Hybrid Vertical-Cavity Laser

DEFF Research Database (Denmark)

2010-01-01

The present invention provides a light source (2) for light circuits on a silicon platform (3). A vertical laser cavity is formed by a gain region (101) arranged between a top mirror (4) and a bottom grating-mirror (12) in a grating region (11) in a silicon layer (10) on a substrate. A waveguide...... (18, 19) for receiving light from the grating region (11) is formed within or to be connected to the grating region, and functions as an 5 output coupler for the VCL. Thereby, vertical lasing modes (16) are coupled to lateral in-plane modes (17, 20) of the in-plane waveguide formed in the silicon...

Crab cavities for linear colliders

CERN Document Server

Burt, G; Carter, R; Dexter, A; Tahir, I; Beard, C; Dykes, M; Goudket, P; Kalinin, A; Ma, L; McIntosh, P; Shulte, D; Jones, Roger M; Bellantoni, L; Chase, B; Church, M; Khabouline, T; Latina, A; Adolphsen, C; Li, Z; Seryi, Andrei; Xiao, L

2008-01-01

Crab cavities have been proposed for a wide number of accelerators and interest in crab cavities has recently increased after the successful operation of a pair of crab cavities in KEK-B. In particular crab cavities are required for both the ILC and CLIC linear colliders for bunch alignment. Consideration of bunch structure and size constraints favour a 3.9 GHz superconducting, multi-cell cavity as the solution for ILC, whilst bunch structure and beam-loading considerations suggest an X-band copper travelling wave structure for CLIC. These two cavity solutions are very different in design but share complex design issues. Phase stabilisation, beam loading, wakefields and mode damping are fundamental issues for these crab cavities. Requirements and potential design solutions will be discussed for both colliders.

TESLA & ILC Cryomodules

Energy Technology Data Exchange (ETDEWEB)

Peterson, T. J. [Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States); Weisend, II, J. G. [Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)

2016-01-01

The TESLA collaboration developed a unique variant of SRF cryomodule designs, the chief feature being use of the large, low pressure helium vapor return pipe as the structural support backbone of the cryomodule. Additional innovative features include all cryogenic piping within the cryomodule (no parallel external cryogenic transfer line), long strings of RF cavities within a single cryomodule, and cryomodules connected in series. Several projects, including FLASH and XFEL at DESY, LCLS-II at SLAC, and the ILC technical design have adopted this general design concept. Advantages include saving space by eliminating the external transfer line, relatively tight packing of RF cavities along the beamline due to fewer warm-cold transitions, and potentially lower costs. However, a primary disadvantage is the relative lack of independence for warm-up, replacement, and cool-down of individual cryomodules.

Vertical-Cavity In-plane Heterostructures: Physics and Applications

DEFF Research Database (Denmark)

Taghizadeh, Alireza; Mørk, Jesper; Chung, Il-Sug

2015-01-01

We show that the in-plane heterostructures realized in vertical cavities with high contrast grating(HCG) reflector enables exotic configurations of heterostructure and photonic wells. In photonic crystal heterostructures forming a photonic well, the property of a confined mode is determined...... by the well width and barrier height. We show that in vertical-cavity in-plane heterostructures, anisotropic dispersion curvatures plays a key role as well, leading to exotic effects such as a photonic well with conduction band like well and a valence band like barrier. We investigate three examples...

Theoretical Investigation of Subwavelength Gratings and Vertical Cavity Lasers Employing Grating Structures

DEFF Research Database (Denmark)

Taghizadeh, Alireza

This thesis deals with theoretical investigations of a newly proposed grating structure, referred to as hybrid grating (HG) as well as vertical cavity lasers based on the grating reflectors. The HG consists of a near-subwavelength grating layer and an unpatterned high-refractive-index cap layer...... directions, which is analogous to electronic quantum wells in conduction or valence bands. Several interesting configurations of heterostructures have been investigated and their potential in fundamental physics study and applications are discussed. For numerical and theoretical studies, a three...... feasibility than the HCG-based ones. Furthermore, the concept of cavity dispersion in vertical cavities is introduced and its importance in the modal properties is numerically investigated. The dispersion curvature of a cavity mode is interpreted as the effective photon mass of the cavity mode. In a vertical...

Hybrid III-V-on-Si Vertical Cavity laser for Optical Interconnects

DEFF Research Database (Denmark)

Park, Gyeong Cheol; Semenova, Elizaveta; Chung, Il-Sug

2013-01-01

Combining a III-V active material onto the Si platform is an attractive approach for silicon photonics light source. We have developed fabrication methods for novel III-V on Si vertical cavity lasers.......Combining a III-V active material onto the Si platform is an attractive approach for silicon photonics light source. We have developed fabrication methods for novel III-V on Si vertical cavity lasers....

Bistable output from a coupled-resonator vertical-cavity laser diode

International Nuclear Information System (INIS)

Fischer, A. J.; Choquette, K. D.; Chow, W. W.; Allerman, A. A.; Geib, K.

2000-01-01

We report a monolithic coupled-resonator vertical-cavity laser with an ion-implanted top cavity and a selectively oxidized bottom cavity which exhibits bistable behavior in the light output versus injection current. Large bistability regions over current ranges as wide as 18 mA have been observed with on/off contrast ratios of greater than 20 dB. The position and width of the bistability region can be varied by changing the bias to the top cavity. Switching between on and off states can be accomplished with changes as small as 250 μW to the electrical power applied to the top cavity. The bistable behavior is the response of the nonlinear susceptibility in the top cavity to the changes in the bottom intracavity laser intensity as the bottom cavity reaches the thermal rollover point

Hybrid vertical-cavity laser with lateral emission into a silicon waveguide

DEFF Research Database (Denmark)

Park, Gyeong Cheol; Xue, Weiqi; Taghizadeh, Alireza

2015-01-01

into the waveguide integrated with the laser. This laser has the advantages of long-wavelength vertical-cavity surface-emitting lasers, such as low threshold and high side-mode suppression ratio, while allowing integration with silicon photonic circuits, and is fabricated using CMOS compatible processes. It has......We experimentally demonstrate an optically-pumped III-V/Si vertical-cavity laser with lateral emission into a silicon waveguide. This on-chip hybrid laser comprises a distributed Bragg reflector, a III-V active layer, and a high-contrast grating reflector, which simultaneously funnels light...

Cryomodule tests of four Tesla-like cavities in the Superconducting RF Test Facility at KEK

Directory of Open Access Journals (Sweden)

Eiji Kako

2010-04-01

Full Text Available A 6-m cryomodule including four Tesla-like cavities was developed, and was tested in the Superconducting RF Test Facility phase-I at KEK. The performance as a total superconducting cavity system was checked in the cryomodule tests at 2 K with high rf power. One of the four cavities achieved a stable pulsed operation at 32  MV/m, which is higher than the operating accelerating gradient in the ILC. The maximum accelerating gradient (E_{acc,max⁡} obtained in the vertical cw tests was maintained or slightly improved in the cryomodule tests operating in a pulse mode. Compensation of the Lorentz force detuning at 31  MV/m was successfully demonstrated by a piezo tuner and predetuning.

Vertical-cavity surface-emitting lasers for medical diagnosis

DEFF Research Database (Denmark)

Ansbæk, Thor

This thesis deals with the design and fabrication of tunable Vertical-Cavity Surface-Emitting Lasers (VCSELs). The focus has been the application of tunable VCSELs in medical diagnostics, specifically OCT. VCSELs are candidates as light sources for swept-source OCT where their high sweep rate, wide...

Characterization and Comparison of Control Units for Piezo Actuators to be used for Lorentz Force Compensation inth ILC

Energy Technology Data Exchange (ETDEWEB)

Bhattacharyya, Sampriti; Pilipenko, Roman; /Fermilab

2010-01-01

Superconducting accelerators, such as the International Linear Collider (ILC), rely on very high Q accelerating cavities to achieve high electric fields at low RF power. Such cavities have very narrow resonances: a few kHz with a 1.3GHz resonance frequency for the ILC. Several mechanical factors cause tune shifts much larger than this: pressure variations in the liquid helium bath; microphonics from pumps and other mechanical devices; and for a pulsed machine such as the ILC, Lorentz force detuning (pressure from the contained RF field). Simple passive stiffening is limited by many manufacturing and material considerations. Therefore, active tuning using piezo actuators is needed. Here we study a supply for their operation. Since commercial power amplifiers are expensive, we analyzed the characteristics of four power amplifiers: (iPZD) built by Istituto Nazionale di Fisica Nucleare (Sezione di Pisa); and a DC-DC converter power supply built in Fermilab (Piezo Master); and two commercial amplifiers, Piezosystem jena and Piezomechanik. This paper presents an analysis and characterization of these amplifiers to understand the cost benefit and reliability when using in a large scale, pulsed beam accelerator like the ILC.

ILC Higgs White Paper

CERN Document Server

Asner, D.M.; Calancha, C.; Fujii, K.; Graf, N.; Haber, H.E.; Ishikawa, A.; Kanemura, S.; Kawada, S.; Kurata, M.; Miyamoto, A.; Neal, H.; Ono, H.; Potter, C.; Strube, J.; Suehara, T.; Tanabe, T.; Tian, J.; Tsumura, J.; Watanuki, S.; Weiglein, G.; Yagyu, K.; Yokoya, H.

2013-01-01

The ILC Higgs White Paper is a review of Higgs Boson theory and experiment at the International Linear Collider (ILC). Theory topics include the Standard Model Higgs, the two-Higgs doublet model, alternative approaches to electroweak symmetry breaking, and precision goals for Higgs boson experiments. Experimental topics include the measurement of the Higgs cross section times branching ratio for various Higgs decay modes at ILC center of mass energies of 250, 500, and 1000 GeV, and the extraction of Higgs couplings and the total Higgs width from these measurements. Luminosity scenarios based on the ILC TDR machine design are used throughout. The gamma-gamma collider option at the ILC is also discussed.

Multivariate optimization of ILC parameters

International Nuclear Information System (INIS)

Bazarov, I.V.; Padamsee, H.S.

2005-01-01

We present results of multiobjective optimization of the International Linear Collider (ILC) which seeks to maximize luminosity at each given total cost of the linac (capital and operating costs of cryomodules, refrigeration and RF). Evolutionary algorithms allow quick exploration of optimal sets of parameters in a complicated system such as ILC in the presence of realistic constraints as well as investigation of various what-if scenarios in potential performance. Among the parameters we varied there were accelerating gradient and Q of the cavities (in a coupled manner following a realistic Q vs. E curve), the number of particles per bunch, the bunch length, number of bunches in the train, etc. We find an optimum which decreases (relative to TESLA TDR baseline) the total linac cost by 22%, capital cost by 25% at the same luminosity of 3 x 10 38 m -2 s -1 . For this optimum the gradient is 35 MV/m, the final spot size is 3.6 nm, and the beam power is 15.9 MV/m. Changing the luminosity by 10 38 m -2 s -1 results in 10% change in the total linac cost and 4% in the capital cost. We have also explored the optimal fronts of luminosity vs. cost for several other scenarios using the same approach. (orig.)

Emittance Correction in the 2006 ILC Bunch Compressor

International Nuclear Information System (INIS)

Tenenbaum, P.; SLAC

2007-01-01

A recent study [1] has indicated substantial potential emittance growth in the ILC bunch compressor due to quad misalignments, BPM misalignments, and pitches in the RF cavities. Table 1 summarizes several results from [1]. In this simulation, quad misalignments and cavity pitches are Gaussian distributed and are considered with respect to the nominal survey line; BPM misalignments are also Gaussian-distributed but are considered with respect to the quadrupole axis. It is assumed that the BPM offsets with respect to the quads are found in a previous quad-shunting BBA step which is not simulated. In this study we seek to repeat the studies documented above, and additionally to perform a study in which additional dispersion bumps are used to further reduce the projected emittance

Transverse-mode-selectable microlens vertical-cavity surface-emitting laser

DEFF Research Database (Denmark)

Chung, Il-Sug; Debernardi, Pierluigi; Lee, Yong Tak

2010-01-01

A new vertical-cavity surface-emitting laser structure employing a thin microlens is suggested and numerically investigated. The laser can be made to emit in either a high-power Gaussian-shaped single-fundamental mode or a high-power doughnut-shaped higher-order mode. The physical origin...

Capture cavity II results at FNAL

Energy Technology Data Exchange (ETDEWEB)

Branlard, Julien; Chase, Brian; Cancelo, G.; Carcagno, R.; Edwards, H.; Fliller, R.; Hanna, B.; Harms, Elvan; Hocker, A.; Koeth, T.; Kucera, M.; /Fermilab

2007-06-01

As part of the research and development towards the International Linear Collider (ILC), several test facilities have been developed at Fermilab. This paper presents the latest Low Level RF (LLRF) results obtained with Capture Cavity II (CCII) at the ILC Test Accelerator (ILCTA) test facility. The main focus will be on controls and RF operations using the SIMCON based LLRF system developed in DESY [1]. Details about hardware upgrades and future work will be discussed.

Numerical Investigation of Vertical Cavity Lasers With High-Contrast Gratings Using the Fourier Modal Method

DEFF Research Database (Denmark)

Taghizadeh, Alireza; Mørk, Jesper; Chung, Il-Sug

2016-01-01

We explore the use of a modal expansion technique, Fourier modal method (FMM), for investigating the optical properties of vertical cavities employing high-contrast gratings (HCGs). Three techniques for determining the resonance frequency and quality factor (Q-factor) of a cavity mode are compared......, the scattering losses of several HCG-based vertical cavities with inplane heterostructures which have promising prospects for fundamental physics studies and on-chip laser applications, are investigated. This type of parametric study of 3D structures would be numerically very demanding using spatial...

Comparative Simulation Studies of Multipacting in Higher-Order-Mode Couplers of Superconducting RF Cavities

International Nuclear Information System (INIS)

Li, Y. M.; Liu, Kexin; Geng, Rongli

2014-01-01

Multipacting (MP) in higher-order-mode (HOM) couplers of the International Linear Collider (ILC) baseline cavity and the Continuous Electron Beam Accelerator Facility (CEBAF) 12 GeV upgrade cavity is studied by using the ACE3P suites, developed by the Advanced Computations Department at SLAC. For the ILC cavity HOM coupler, the simulation results show that resonant trajectories exist in three zones, corresponding to an accelerating gradient range of 0.6A-1.6 MV/m, 21A-34 MV/m, 32A-35 MV/m, and > 40MV/m, respectively. For the CEBAF 12 GeV upgrade cavity HOM coupler, resonant trajectories exist in one zone, corresponding to an accelerating gradient range of 6A-13 MV/m. Potential implications of these MP barriers are discussed in the context of future high energy pulsed as well as medium energy continuous wave (CW) accelerators based on superconducting radio frequency cavities. Frequency scaling of MPA's predicted in HOM couplers of the ILC, CBEAF upgrade, SNS and FLASH third harmonic cavity is given and found to be in good agreement with the analytical result based on the parallel plate model

Comparative Simulation Studies of Multipacting in Higher-Order-Mode Couplers of Superconducting RF Cavities

Energy Technology Data Exchange (ETDEWEB)

Li, Y. M. [Peking University, Beijing (China); Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Liu, Kexin [Peking University, Beijing (China); Geng, Rongli [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)

2014-02-01

Multipacting (MP) in higher-order-mode (HOM) couplers of the International Linear Collider (ILC) baseline cavity and the Continuous Electron Beam Accelerator Facility (CEBAF) 12 GeV upgrade cavity is studied by using the ACE3P suites, developed by the Advanced Computations Department at SLAC. For the ILC cavity HOM coupler, the simulation results show that resonant trajectories exist in three zones, corresponding to an accelerating gradient range of 0.6-1.6 MV/m, 21-34 MV/m, 32-35 MV/m, and > 40MV/m, respectively. For the CEBAF 12 GeV upgrade cavity HOM coupler, resonant trajectories exist in one zone, corresponding to an accelerating gradient range of 6-13 MV/m. Potential implications of these MP barriers are discussed in the context of future high energy pulsed as well as medium energy continuous wave (CW) accelerators based on superconducting radio frequency cavities. Frequency scaling of MP's predicted in HOM couplers of the ILC, CBEAF upgrade, SNS and FLASH third harmonic cavity is given and found to be in good agreement with the analytical result based on the parallel plate model.

LHC-ILC synergy

CERN Document Server

Godbole, Rohini M

2006-01-01

I will begin by making a few general comments on the synergy between the Large Hadron Collider (LHC) which will go in action in 2007 and the International Linear Collider (ILC) which is under planning. I will then focus on the synergy between the LHC and the PLC option at the ILC, which is expected to be realised in the later stages of the ILC program. In this I will cover the possible synergy in the Higgs sector (with and without CP violation), in the determination of the anomalous vector boson couplings and last but not the least, in the search for extra dimensions and radions.

Efficient quality-eactor estimation of a vertical cavity employing a high-contrast grating

DEFF Research Database (Denmark)

Taghizadeh, Alireza; Mørk, Jesper; Chung, Il-Sug

2017-01-01

Hybrid vertical cavity lasers employing high-contrast grating reflectors are attractive for Si-integrated light source applications. Here, a method for reducing a three-dimensional (3D) optical simulation of this laser structure to lower-dimensional simulations is suggested, which allows for very...... fast and approximate analysis of the quality-factor of the 3D cavity. This approach enables us to efficiently optimize the laser cavity design without performing cumbersome 3D simulations....

Continuous-wave optically pumped green perovskite vertical-cavity surface-emitter

KAUST Repository

Alias, Mohd Sharizal; Liu, Zhixiong; Alatawi, Abdullah; Ng, Tien Khee; Wu, Tao; Ooi, Boon S.

2017-01-01

We report an optically pumped green perovskite vertical-cavity surface-emitter operating in continuous-wave (CW) with a power density threshold of ~89 kW/cm2. The device has an active region of CH3NH3PbBr3 embedded in a dielectric microcavity

Polymer-coated vertical-cavity surface-emitting laser diode vapor sensor

DEFF Research Database (Denmark)

Ansbæk, Thor; Nielsen, Claus Højgaard; Larsen, Niels Bent

2010-01-01

We report a new method for monitoring vapor concentration of volatile organic compounds using a vertical-cavity surface-emitting laser (VCSEL). The VCSEL is coated with a polymer thin film on the top distributed Bragg reflector (DBR). The analyte absorption is transduced to the electrical domain ...

Comparative simulation studies of multipacting in higher-order-mode couplers of superconducting rf cavities

Directory of Open Access Journals (Sweden)

Y. M. Li

2014-02-01

Full Text Available Multipacting (MP in higher-order-mode (HOM couplers of the International Linear Collider (ILC baseline cavity and the Continuous Electron Beam Accelerator Facility (CEBAF 12 GeV upgrade cavity is studied by using the ACE3P suites, developed by the Advanced Computations Department at SLAC. For the ILC cavity HOM coupler, the simulation results show that resonant trajectories exist in three zones, corresponding to an accelerating gradient range of 0.6–1.6  MV/m, 21–34   MV/m, 32–35  MV/m and >40  MV/m, respectively. For the CEBAF 12 GeV upgrade cavity HOM coupler, resonant trajectories exist in one zone, corresponding to an accelerating gradient range of 6–13  MV/m. Potential implications of these MP barriers are discussed in the context of future high-energy pulsed as well as medium-energy continuous wave accelerators based on superconducting radio frequency cavities. Frequency scaling of MP’s predicted in HOM couplers of the ILC, CEBAF upgrade, Spallation Neutron Source (SNS, and Free-Electron Laser in Hamburg (FLASH third harmonic cavity is given and found to be in good agreement with the analytical result based on the parallel plate model.

Vertical and horizontal test results of 3.9-GHz accelerating cavities at FNAL

Energy Technology Data Exchange (ETDEWEB)

Khabiboulline, T.; Edwards, H.; Foley, M.; Harms, E.; Hocker, James Andrew; Mitchell, D.; Rowe, A.; Solyak, N.; /Fermilab

2008-06-01

The 3rd harmonic 3.9GHz accelerating cavity was proposed to improve the beam performance of the VUV FEL, FLASH. In the frame of a collaborative agreement, Fermilab will provide DESY with a cryomodule containing a string of four cavities. Seven 9-cell Nb cavities were tested and six of them did reach accelerating gradient up to 24 MV/m almost twice more than design value of 14 MV/m. Two of these cavities are with new HOM couplers with improved design. In this paper we present all results of the vertical and horizontal tests.

3D detector and electronics integration technologies: Applications to ILC, SLHC, and beyond

International Nuclear Information System (INIS)

Lipton, Ronald

2011-01-01

The application of vertically integrated (3D) electronics to particle physics has been explored by the our group for the past several years. We have successfully designed the first vertically integrated demonstrator chip for ILC vertex detection in the three-tier MIT-Lincoln Labs process. We have also studied sensor integration with electronics through oxide bonding and silicon-on-insulator technology. This paper will discuss the status of these studies and prospects for future work.

3D detector and electronics integration technologies: Applications to ILC, SLHC, and beyond

Energy Technology Data Exchange (ETDEWEB)

Lipton, Ronald, E-mail: lipton@fnal.gov [Fermilab, P.O. Box 500, Batavia, IL 60510 (United States)

2011-04-21

The application of vertically integrated (3D) electronics to particle physics has been explored by the our group for the past several years. We have successfully designed the first vertically integrated demonstrator chip for ILC vertex detection in the three-tier MIT-Lincoln Labs process. We have also studied sensor integration with electronics through oxide bonding and silicon-on-insulator technology. This paper will discuss the status of these studies and prospects for future work.

ILC2s and fungal allergy

Directory of Open Access Journals (Sweden)

Hirohito Kita

2015-07-01

Full Text Available Innate lymphoid cells (ILCs have emerged recently as an important component of the immune system and the cell type that regulates mucosal immune responses and tissue homeostasis. Group 2 ILCs (ILC2s, a subset of ILCs, reside in various tissues and are characterized by their capacity to produce type 2 cytokines and tissue growth factors. These ILC2s play an important role in allergic immune responses by linking signals in the atmospheric environment to the immune system. Fungi are one of the major allergens associated with human asthma, and animal and in vitro models using the fungal allergens have provided significant information toward our understanding of the mechanisms of allergic disease. In mouse models of fungus-induced allergic airway inflammation, IL-33, IL-25, and TSLP are released by airway epithelial cells. Lung ILC2s that respond to these cytokines quickly produce a large quantity of type 2 cytokines, resulting in airway eosinophilia, mucus production, and airway hyperreactivity even in the absence of adaptive immune cells. Evidence also suggests that ILC2s interact with conventional immune cells, such as CD4+ T cells, and facilitate development of adaptive immune response and persistent airway inflammation. ILC2s are also present in respiratory mucosa in humans. Further investigations into the biology of ILC2s and their roles in the pathophysiology of allergic diseases will provide major conceptual advances in the field and may provide useful information toward development of new therapeutic strategies for patients.

Photon production at the interaction point of the ILC

Energy Technology Data Exchange (ETDEWEB)

Appleby, R. [Manchester Univ., Cockcroft Institute and the University of Oxford Road, Manchester (United Kingdom); Bambade, P. [Univ Paris-Sud, LAL, CNRS/IN2P3, 91 - Orsay (France)

2008-01-15

The intense beam-beam effect at the interaction point of the International Linear Collider (ILC) causes large disruption of the beams and the production of photons. These photons, arising dominantly through Beamstrahlung emission, are problematic for the machine design as they need to be transported and dumped in a controlled way. In this work, we perform simulations of the beam-beam interaction to predict photon production rates and distributions for the different beam parameters considered at ILC. The results are expressed in terms of a set of cones of excluded power, allowing to define the beam-stay-clear requirements relevant for different cases and contexts. A comparison is also made with theoretical expectations. The suggested photon cone half-opening angles are 0.75 and 0.85 mrad in the horizontal and vertical planes, respectively. These cones cover all machine energies and parameter sets, and include the low power Compton photons. (authors)

ILC Operating Scenarios

Energy Technology Data Exchange (ETDEWEB)

Barklow, T.; Brau, J.; Fujii, K.; Gao, J.; List, J.; Walker, N.; Yokoya, K.; Collaboration: ILC Parameters Joint Working Group

2015-06-15

The ILC Technical Design Report documents the design for the construction of a linear collider which can be operated at energies up to 500 GeV. This report summarizes the outcome of a study of possible running scenarios, including a realistic estimate of the real time accumulation of integrated luminosity based on ramp-up and upgrade processes. The evolution of the physics outcomes is emphasized, including running initially at 500 GeV, then at 350 GeV and 250 GeV. The running scenarios have been chosen to optimize the Higgs precision measurements and top physics while searching for evidence for signals beyond the standard model, including dark matter. In addition to the certain precision physics on the Higgs and top that is the main focus of this study, there are scientific motivations that indicate the possibility for discoveries of new particles in the upcoming operations of the LHC or the early operation of the ILC. Follow-up studies of such discoveries could alter the plan for the centre-of-mass collision energy of the ILC and expand the scientific impact of the ILC physics program. It is envisioned that a decision on a possible energy upgrade would be taken near the end of the twenty year period considered in this report.

Sub-monolayer dot vertical-cavity surface-emitting lasers

International Nuclear Information System (INIS)

Blokhin, S.A.; Maleev, N.A.; Kuz'menkov, A.G.

2006-01-01

Vertical-cavity surface-emitting lasers (VCSELs) based on submonolayer InGaAs quantum-dot active region and doped with AlGaAs/GaAs distributed Bragg reflectors were grown by molecular beam epitaxy. 3 μm aperture single-mode VCSELs demonstrate lasing at 980 nm with threshold current of 0.6 mA, maximum output power of 4 mW and external differential efficiency as high as 68%. Ultimately low internal optical losses were measured for these multimode sub-monolayer quantum dot VCSELs [ru

Localization of rf breakdowns in a standing wave cavity

Directory of Open Access Journals (Sweden)

Faya Wang

2009-04-01

Full Text Available At SLAC, a five-cell, normal-conducting, L-band (1.3 GHz, standing-wave (SW cavity was built as a prototype positron capture accelerator for the ILC. The structure met the ILC gradient goal but required extensive rf processing. When rf breakdowns occurred, a large variation was observed in the decay rate of the stored energy in the cavity after the input power was shut off. It appeared that the breakdowns were isolating sections of the cavity, and that the trapped energy in those sections was then partitioned among its natural modes, producing a distinct beating pattern during the decay. To explore this phenomenon further, an equivalent circuit model of cavity was created that reproduces well its normal operating characteristics. The model was then used to compute the spectra of trapped energy for different numbers of isolated cells. The resulting modal patterns agree well with those of the breakdown data, and thus such a comparison appears to provide a means of identifying the irises on which the breakdowns occurred.

Continuously tunable monomode mid-infrared vertical external cavity surface emitting laser on Si

Science.gov (United States)

Khiar, A.; Rahim, M.; Fill, M.; Felder, F.; Hobrecker, F.; Zogg, H.

2010-10-01

A tunable PbTe based mid-infrared vertical external cavity surface emitting laser is described. The active part is a ˜1 μm thick PbTe layer grown epitaxially on a Bragg mirror on the Si-substrate. The cavity is terminated with a curved Si/SiO Bragg top mirror and pumped optically with a 1.55 μm laser. Cavity length is <100 μm in order that only one longitudinal mode is supported. By changing the cavity length, up to 5% wavelength continuous and mode-hop free tuning is achieved at fixed temperature. The total tuning extends from 5.6 to 4.7 μm at 100-170 K operation temperature.

Development of an S-band cavity Beam Position Monitor for ATF2

Science.gov (United States)

Heo, A.; Kim, E.-S.; Kim, H.; Son, D.; Honda, Y.; Tauchi, T.

2013-04-01

We have developed an S-band cavity Beam Position Monitor (BPM) in order to measure the position of an electron beam in the final focus area at ATF2, which is the test facility for the final focus design for the International Linear Collider (ILC). The lattice of the ILC Beam Delivery System (BDS) has been modified, requiring a larger physical aperture of 40 mm in the final focus area. The beam orbit measurement in this area is now covered with high resolution S-Band cavity BPMs. In this paper we summarize the design of the cavity BPM and the first experimental results. The calibration slopes were measured as 0.87 counts/μm in the x-coordinate direction and 1.16 counts/μm in the y-coordinate direction.

Progress and Plans for R&D and the Conceptual Design of the ILC High Gradient Structures

CERN Document Server

Padamsee, Hasan

2005-01-01

Gradients and Q's in the dominant ILC candidate structure have shown steady improvement, reaching 35-40 MV/m in the last year by using the best techniques of electropolishing, high pressure rinsing and 120 C baking for 48 hours. Progress and plans for t his structure will be reviewed. Above 40 MV/m, the surface magnetic field encroaches the rf critical magnetic field, believed to fall between 1750 and 2000 Oe, depending on the theory. One way to circumvent the limit is to modify the cavity shape to reduc e the ratio of peak magnetic to accelerating field. Two candidate shapes are evolving, the Re-entrant shape and the Low-Loss shape. Although field emission is aggravated by higher electric fields, it does not present a brick wall limit because high pressu re rinsing at 100 bar eliminates microparticles which cause field emission. Fundamental and higher mode properties of these new shapes will be compared with the dominant ILC candidate. Results of single and multicell cavities will be presented. The record fi...

Characterization of innate lymphoid cells (ILC) in human skin and blood demonstrates increase of NKp44+ ILC3 in psoriasis

Science.gov (United States)

Tosi, Isabella; Grys, Katarzyna; Sreeneebus, Hemawtee; Perera, Gayathri K; Chapman, Anna; Smith, Catherine H; Di Meglio, Paola; Nestle, Frank O

2013-01-01

Innate lymphoid cells (ILC) are increasingly appreciated as key regulators of tissue immunity. However, their role in human tissue homeostasis and disease remains to be fully elucidated. Here we characterise the ILC in human skin from healthy individuals and from the inflammatory skin disease psoriasis. We show that a substantial proportion of IL-17A and IL-22 producing cells in skin and blood of normal individuals and psoriasis patients are CD3 negative innate lymphocytes. Deep immunophenotyping of human ILC subsets showed a statistically significant increase in the frequency of circulating NKp44+ ILC3 in blood of psoriasis patients compared to healthy individuals or atopic dermatitis patients. More than 50% of circulating NKp44+ ILC3 expressed cutaneous lymphocyte-associated antigen indicating their potential for skin homing. Analysis of skin tissue revealed a significantly increased frequency of total ILC in skin compared to blood. Moreover the frequency of NKp44+ ILC3 was significantly increased in non-lesional psoriatic skin compared to normal skin. A detailed time course of a psoriasis patient treated with anti-TNF showed a close association between therapeutic response, decrease in inflammatory skin lesions, and decrease of circulating NKp44+ ILC3. Overall, data from this initial observational study suggest a potential role for NKp44+ ILC3 in psoriasis pathogenesis. PMID:24352038

Beam Dynamics Challenges for the ILC

International Nuclear Information System (INIS)

Kubo, Kiyoshi; Seryi, Andrei; Walker, Nicholas; Wolski, Andy

2008-01-01

The International Linear Collider (ILC) is a proposal for 500 GeV center-of-mass electron-positron collider, with a possible upgrade to ∼1 TeV center-of-mass. At the heart of the ILC are the two ∼12 km 1.3 GHz superconducting RF (SCRF) linacs which will accelerate the electron and positron beams to an initial maximum energy of 250 GeV each. The Global Design Effort (GDE)--responsible for the world-wide coordination of this uniquely international project--published the ILC Reference Design Report in August of 2007 [1]. The ILC outlined in the RDR design stands on a legacy of over fifteen-years of R and D. The GDE is currently beginning the next step in this ambitious project, namely an Engineering Design phase, which will culminate with the publication of an Engineering Design Report (EDR) in mid-2010. Throughout the history of linear collider development, beam dynamics has played an essential role. In particular, the need for complex computer simulations to predict the performance of the machine has always been crucial, not least because the parameters of the ILC represent in general a large extrapolation from where current machines operate today; many of the critical beam-dynamics features planned for the ILC can ultimately only be truly tested once the ILC has been constructed. It is for this reason that beam dynamics activities will continue to be crucial during the Engineering Design phase, as the available computer power and software techniques allow ever-more complex and realistic models of the machine to be developed. Complementary to the computer simulation efforts are the need for well-designed experiments at beam-test facilities, which--while not necessarily producing a direct demonstration of the ILC-like parameters for the reasons mentioned above--can provide important input and benchmarking for the computer models

Continuous-wave optically pumped green perovskite vertical-cavity surface-emitter

KAUST Repository

Alias, Mohd Sharizal

2017-09-11

We report an optically pumped green perovskite vertical-cavity surface-emitter operating in continuous-wave (CW) with a power density threshold of ~89 kW/cm2. The device has an active region of CH3NH3PbBr3 embedded in a dielectric microcavity; this feat was achieved with a combination of optimal spectral alignment of the optical cavity modes with the perovskite optical gain, an adequate Q-factor of the microcavity, adequate thermal stability, and improved material quality with a smooth, passivated, and annealed thin active layer. Our results signify a way towards efficient CW perovskite emitter operation and electrical injection using low-cost fabrication methods for addressing monolithic optoelectronic integration and lasing in the green gap.

Cavity Processing and Preparation of 650 MHz Elliptical Cell Cavities for PIP-II

Energy Technology Data Exchange (ETDEWEB)

Rowe, Allan [Fermilab; Chandrasekaran, Saravan Kumar [Fermilab; Grassellino, Anna [Fermilab; Melnychuk, Oleksandr [Fermilab; Merio, Margherita [Fermilab; Reid, Thomas [Argonne (main); Sergatskov, Dmitri [Fermilab

2017-05-01

The PIP-II project at Fermilab requires fifteen 650 MHz SRF cryomodules as part of the 800 MeV LINAC that will provide a high intensity proton beam to the Fermilab neutrino program. A total of fifty-seven high-performance SRF cavities will populate the cryomodules and will operate in both pulsed and continuous wave modes. These cavities will be processed and prepared for performance testing utilizing adapted cavity processing infrastructure already in place at Fermilab and Argonne. The processing recipes implemented for these structures will incorporate state-of-the art processing and cleaning techniques developed for 1.3 GHz SRF cavities for the ILC, XFEL, and LCLS-II projects. This paper describes the details of the processing recipes and associated chemistry, heat treatment, and cleanroom processes at the Fermilab and Argonne cavity processing facilities. This paper also presents single and multi-cell cavity test results with quality factors above 5·10¹⁰ and accelerating gradients above 30 MV/m.

Characteristic of innate lymphoid cells (ILC

Directory of Open Access Journals (Sweden)

Mateusz Adamiak

2014-12-01

Full Text Available Innate lymphoid cells (ILC is a newly described family of immune cells that are part of the natural immunity which is important not only during infections caused by microorganisms, but also in the formation of lymphoid tissue, tissue remodeling after damage due to injury and homeostasis tissue stromal cells. Family ILC cells form NK cells (natural killer and lymphoid tissue inducer T cells (LTi, which, although they have different functions, are evolutionarily related. NK cells are producing mainly IFN-γ, whereas LTi cells as NKR+LTi like, IL-17 and/or IL-22, which suggests that the last two cells, can also represent the innate versions of helper T cell - TH17 and TH22. Third population of ILC is formed by cells with characteristics such as NK cells and LTi (ILC22 - which are named NK22 cells, natural cytotoxicity receptor 22 (NCR22 cells or NK receptor-positive (LTi NKR+ LTi cells. Fourth population of ILC cells are ILC17 - producing IL-17, while the fifth is formed by natural helper type 2 T cells (nTH2, nuocyte, innate type 2 helper cells (IH2 and multi-potent progenitor type 2 cells (MPPtype2. Cells of the last population synthesize IL-5 and IL-13. It is assumed that an extraordinary functional diversity of ILC family, resembles T cells, probably because they are under the control of the corresponding transcription factors - as direct regulation factors, such as the family of lymphocytes T.

Bistable laser device with multiple coupled active vertical-cavity resonators

Science.gov (United States)

Fischer, Arthur J.; Choquette, Kent D.; Chow, Weng W.

2003-08-19

A new class of bistable coupled-resonator vertical-cavity semiconductor laser devices has been developed. These bistable laser devices can be switched, either electrically or optically, between lasing and non-lasing states. A switching signal with a power of a fraction of a milliwatt can change the laser output of such a device by a factor of a hundred, thereby enabling a range of optical switching and data encoding applications.

Vertical-cavity surface-emitting laser vapor sensor using swelling polymer reflection modulation

DEFF Research Database (Denmark)

Ansbæk, Thor; Nielsen, Claus Højgård; Dohn, Søren

2012-01-01

Vapor detection using a low-refractive index polymer for reflection modulation of the top mirror in a vertical-cavity surface-emitting laser (VCSEL) is demonstrated. The VCSEL sensor concept presents a simple method to detect the response of a sensor polymer in the presence of volatile organic...

High-Speed Semiconductor Vertical-Cavity Surface-Emitting Lasers for Optical Data-Transmission Systems (Review)

Science.gov (United States)

Blokhin, S. A.; Maleev, N. A.; Bobrov, M. A.; Kuzmenkov, A. G.; Sakharov, A. V.; Ustinov, V. M.

2018-01-01

The main problems of providing a high-speed operation semiconductor lasers with a vertical microcavity (so-called "vertical-cavity surface-emitting lasers") under amplitude modulation and ways to solve them have been considered. The influence of the internal properties of the radiating active region and the electrical parasitic elements of the equivalent circuit of lasers are discussed. An overview of approaches that lead to an increase of the cutoff parasitic frequency, an increase of the differential gain of the active region, the possibility of the management of mode emission composition and the lifetime of photons in the optical microcavities, and reduction of the influence of thermal effects have been presented. The achieved level of modulation bandwidth of ˜30 GHz is close to the maximum achievable for the classical scheme of the direct-current modulation, which makes it necessary to use a multilevel modulation format to further increase the information capacity of optical channels constructed on the basis of vertical-cavity surface-emitting lasers.

Heat transfer of natural convection in a rectangular cavity with vertical walls of different temperatures

International Nuclear Information System (INIS)

Seki, Nobuhiro; Fukusako, Shoichiro; Inaba, Hideo

1978-01-01

In the present study the behavior of heat transfer in a rectangular cavity with one isothermal vertical wall heated and the other cooled is investigated. Heat transfer coefficients on the vertical walls are measured for fluids with Prandtl number Pr of 3 to 40,000 in case of aspect-ratio H/W from 5 to 47.5 and their correlated results are presented for laminar, transition and turbulent regions, respectively. It is shown that the present arrangement (Nu sub(H) - Ra sub(H)) using the height of cavity as a representative length may significantly be useful in the various heat transfer modes accompanied with flow patterns of them. (auth.)

Wakefield and RF Kicks Due to Coupler Asymmetry in TESLA-Type Accelerating Cavities

International Nuclear Information System (INIS)

Bane, K

2008-01-01

In a future linear collider, such as the International Linear Collider (ILC), trains of high current, low emittance bunches will be accelerated in a linac before colliding at the interaction point. Asymmetries in the accelerating cavities of the linac will generate fields that will kick the beam transversely and degrade the beam emittance and thus the collider performance. In the main linac of the ILC, which is filled with TESLA-type superconducting cavities, it is the fundamental (FM) and higher mode (HM) couplers that are asymmetric and thus the source of such kicks. The kicks are of two types: one, due to (the asymmetry in) the fundamental RF fields and the other, due to transverse wakefields that are generated by the beam even when it is on axis. In this report we calculate the strength of these kicks and estimate their effect on the ILC beam. The TESLA cavity comprises nine cells, one HM coupler in the upstream end, and one (identical, though rotated) HM coupler and one FM coupler in the downstream end (for their shapes and location see Figs. 1, 2) [1]. The cavity is 1.1 m long, the iris radius 35 mm, and the coupler beam pipe radius 39 mm. Note that the couplers reach closer to the axis than the irises, down to a distance of 30 mm

Spectral-Modulation Characteristics of Vertical-Cavity Surface-Emitting Lasers

Science.gov (United States)

Vas'kovskaya, M. I.; Vasil'ev, V. V.; Zibrov, S. A.; Yakovlev, V. P.; Velichanskii, V. L.

2018-01-01

The requirements imposed on vertical-cavity surface-emitting lasers in a number of metrological problems in which optical pumping of alkali atoms is used are considered. For lasers produced by different manufacturers, these requirements are compared with the experimentally observed spectral characteristics at a constant pump current and in the microwave modulation mode. It is shown that a comparatively small number of lasers in the microwave modulation mode make it possible to obtain the spectrum required for atomic clocks based on the coherent population-trapping effect.

ILC Reference Design Report Volume 4 - Detectors

CERN Document Server

Behnke, Ties; Jaros, John; Miyamoto, Akiya; Aarons, Gerald; Abe, Toshinori; Abernathy, Jason; Ablikim, Medina; Abramowicz, Halina; Adey, David; Adloff, Catherine; Adolphsen, Chris; Afanaciev, Konstantin; Agapov, Ilya; Ahn, Jung-Keun; Aihara, Hiroaki; Akemoto, Mitsuo; del Carmen Alabau, Maria; Albert, Justin; Albrecht, Hartwig; Albrecht, Michael; Alesini, David; Alexander, Gideon; Alexander, Jim; Allison, Wade; Amann, John; Amirikas, Ramila; An, Qi; Anami, Shozo; Ananthanarayan, B.; Anderson, Terry; Andricek, Ladislav; Anduze, Marc; Anerella, Michael; Anfimov, Nikolai; Angal-Kalinin, Deepa; Antipov, Sergei; Antoine, Claire; Aoki, Mayumi; Aoza, Atsushi; Aplin, Steve; Appleby, Rob; Arai, Yasuo; Araki, Sakae; Arkan, Tug; Arnold, Ned; Arnold, Ray; Arnowitt, Richard; Artru, Xavier; Arya, Kunal; Aryshev, Alexander; Asakawa, Eri; Asiri, Fred; Asner, David; Atac, Muzaffer; Atoian, Grigor; Attié, David; Augustin, Jean-Eudes; Augustine, David B.; Ayres, Bradley; Aziz, Tariq; Baars, Derek; Badaud, Frederique; Baddams, Nigel; Bagger, Jonathan; Bai, Sha; Bailey, David; Bailey, Ian R.; Baker, David; Balalykin, Nikolai I.; Balbuena, Juan Pablo; Baldy, Jean-Luc; Ball, Markus; Ball, Maurice; Ballestrero, Alessandro; Ballin, Jamie; Baltay, Charles; Bambade, Philip; Ban, Syuichi; Band, Henry; Bane, Karl; Banerjee, Bakul; Barbanotti, Serena; Barbareschi, Daniele; Barbaro-Galtieri, Angela; Barber, Desmond P.; Barbi, Mauricio; Bardin, Dmitri Y.; Barish, Barry; Barklow, Timothy L.; Barlow, Roger; Barnes, Virgil E.; Barone, Maura; Bartels, Christoph; Bartsch, Valeria; Basu, Rahul; Battaglia, Marco; Batygin, Yuri; Baudot, Jerome; Baur, Ulrich; Elwyn Baynham, D.; Beard, Carl; Bebek, Chris; Bechtle, Philip; Becker, Ulrich J.; Bedeschi, Franco; Bedjidian, Marc; Behera, Prafulla; Bellantoni, Leo; Bellerive, Alain; Bellomo, Paul; Bentson, Lynn D.; Benyamna, Mustapha; Bergauer, Thomas; Berger, Edmond; Bergholz, Matthias; Beri, Suman; Berndt, Martin; Bernreuther, Werner; Bertolini, Alessandro; Besancon, Marc; Besson, Auguste; 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Finocchiaro, Giuseppe; Fischer, Peter; Fisher, Peter; Eugene Fisk, H.; Fitton, Mike D.; Fleck, Ivor; Fleischer, Manfred; Fleury, Julien; Flood, Kevin; Foley, Mike; Ford, Richard; Fortin, Dominique; Foster, Brian; Fourches, Nicolas; Francis, Kurt; Frey, Ariane; Frey, Raymond; Friedsam, Horst; Frisch, Josef; Frishman, Anatoli; Fuerst, Joel; Fujii, Keisuke; Fujimoto, Junpei; Fukuda, Masafumi; Fukuda, Shigeki; Funahashi, Yoshisato; Funk, Warren; Furletova, Julia; Furukawa, Kazuro; Furuta, Fumio; Fusayasu, Takahiro; Fuster, Juan; Gadow, Karsten; Gaede, Frank; Gaglione, Renaud; Gai, Wei; Gajewski, Jan; Galik, Richard; Galkin, Alexei; Galkin, Valery; Gallin-Martel, Laurent; Gannaway, Fred; Gao, Jian She; Gao, Jie; Gao, Yuanning; Garbincius, Peter; Garcia-Tabares, Luis; Garren, Lynn; Garrido, Luís; Garutti, Erika; Garvey, Terry; Garwin, Edward; Gascón, David; Gastal, Martin; Gatto, Corrado; Gatto, Raoul; Gay, Pascal; Ge, Lixin; Ge, Ming Qi; Ge, Rui; Geiser, Achim; Gellrich, Andreas; Genat, Jean-Francois; Geng, Zhe Qiao; Gentile, Simonetta; Gerbick, Scot; Gerig, Rod; Ghosh, Dilip Kumar; Ghosh, Kirtiman; Gibbons, Lawrence; Giganon, Arnaud; Gillespie, Allan; Gillman, Tony; Ginzburg, Ilya; Giomataris, Ioannis; Giunta, Michele; Gladkikh, Peter; Gluza, Janusz; Godbole, Rohini; Godfrey, Stephen; Goldhaber, Gerson; Goldstein, Joel; Gollin, George D.; Gonzalez-Sanchez, Francisco Javier; Goodrick, Maurice; Gornushkin, Yuri; Gostkin, Mikhail; Gottschalk, Erik; Goudket, Philippe; Gough Eschrich, Ivo; Gournaris, Filimon; Graciani, Ricardo; Graf, Norman; Grah, Christian; Grancagnolo, Francesco; Grandjean, Damien; Grannis, Paul; Grassellino, Anna; Graugés, Eugeni; Gray, Stephen; Green, Michael; Greenhalgh, Justin; Greenshaw, Timothy; Grefe, Christian; Gregor, Ingrid-Maria; Grenier, Gerald; Grimes, Mark; Grimm, Terry; Gris, Philippe; Grivaz, Jean-Francois; Groll, Marius; Gronberg, Jeffrey; Grondin, Denis; Groom, Donald; Gross, Eilam; Grunewald, Martin; Grupen, Claus; Grzelak, Grzegorz; Gu, Jun; Gu, Yun-Ting; Guchait, Monoranjan; Guiducci, Susanna; Guler, Ali Murat; Guler, Hayg; Gulmez, Erhan; Gunion, John; Guo, Zhi Yu; Gurtu, Atul; Ha, Huy Bang; Haas, Tobias; Haase, Andy; Haba, Naoyuki; Haber, Howard; Haensel, Stephan; Hagge, Lars; Hagura, Hiroyuki; Hajdu, Csaba; Haller, Gunther; Haller, Johannes; Hallermann, Lea; Halyo, Valerie; Hamaguchi, Koichi; Hammond, Larry; Han, Liang; Han, Tao; Hand, Louis; Handu, Virender K.; Hano, Hitoshi; Hansen, Christian; Hansen, Jørn Dines; Hansen, Jorgen Beck; Hara, Kazufumi; Harder, Kristian; Hartin, Anthony; Hartung, Walter; Hast, Carsten; Hauptman, John; Hauschild, Michael; Hauviller, Claude; Havranek, Miroslav; Hawkes, Chris; Hawkings, Richard; Hayano, Hitoshi; Hazumi, Masashi; He, An; He, Hong Jian; Hearty, Christopher; Heath, Helen; Hebbeker, Thomas; Hedberg, Vincent; Hedin, David; Heifets, Samuel; Heinemeyer, Sven; Heini, Sebastien; Helebrant, Christian; Helms, Richard; Heltsley, Brian; Henrot-Versille, Sophie; Henschel, Hans; Hensel, Carsten; Hermel, Richard; 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Inoue, Hitoshi; Inoue, Youichi; Introzzi, Gianluca; Ioakeimidi, Katerina; Ishihara, Satoshi; Ishikawa, Akimasa; Ishikawa, Tadashi; Issakov, Vladimir; Ito, Kazutoshi; Ivanov, V.V.; Ivanov, Valentin; Ivanyushenkov, Yury; Iwasaki, Masako; Iwashita, Yoshihisa; Jackson, David; Jackson, Frank; Jacobsen, Bob; Jaganathan, Ramaswamy; Jamison, Steven; Janssen, Matthias Enno; Jaramillo-Echeverria, Richard; Jauffret, Clement; Jawale, Suresh B.; Jeans, Daniel; Jedziniak, Ron; Jeffery, Ben; Jehanno, Didier; Jenner, Leo J.; Jensen, Chris; Jensen, David R.; Jiang, Hairong; Jiang, Xiao Ming; Jimbo, Masato; Jin, Shan; Keith Jobe, R.; Johnson, Anthony; Johnson, Erik; Johnson, Matt; Johnston, Michael; Joireman, Paul; Jokic, Stevan; Jones, James; Jones, Roger M.; Jongewaard, Erik; Jönsson, Leif; Joshi, Gopal; Joshi, Satish C.; Jung, Jin-Young; Junk, Thomas; Juste, Aurelio; Kado, Marumi; Kadyk, John; Käfer, Daniela; Kako, Eiji; Kalavase, Puneeth; Kalinin, Alexander; Kalinowski, Jan; Kamitani, Takuya; Kamiya, Yoshio; Kamiya, Yukihide; Kamoshita, Jun-ichi; Kananov, Sergey; Kanaya, Kazuyuki; Kanazawa, Ken-ichi; Kanemura, Shinya; Kang, Heung-Sik; Kang, Wen; Kanjial, D.; Kapusta, Frédéric; Karataev, Pavel; Karchin, Paul E.; Karlen, Dean; Karyotakis, Yannis; Kashikhin, Vladimir; Kashiwagi, Shigeru; Kasley, Paul; Katagiri, Hiroaki; Kato, Takashi; Kato, Yukihiro; Katzy, Judith; Kaukher, Alexander; Kaur, Manjit; Kawagoe, Kiyotomo; Kawamura, Hiroyuki; Kazakov, Sergei; Kekelidze, V.D.; Keller, Lewis; Kelley, Michael; Kelly, Marc; Kelly, Michael; Kennedy, Kurt; Kephart, Robert; Keung, Justin; Khainovski, Oleg; Khan, Sameen Ahmed; Khare, Prashant; Khovansky, Nikolai; Kiesling, Christian; Kikuchi, Mitsuo; Kilian, Wolfgang; Killenberg, Martin; Kim, Donghee; Kim, Eun San; Kim, Eun-Joo; Kim, Guinyun; Kim, Hongjoo; Kim, Hyoungsuk; Kim, Hyun-Chui; Kim, Jonghoon; Kim, Kwang-Je; Kim, Kyung Sook; Kim, Peter; Kim, Seunghwan; Kim, Shin-Hong; Kim, Sun Kee; Kim, Tae Jeong; Kim, Youngim; Kim, Young-Kee; Kimmitt, Maurice; Kirby, Robert; Kircher, François; Kisielewska, Danuta; Kittel, Olaf; Klanner, Robert; Klebaner, Arkadiy L.; Kleinwort, Claus; Klimkovich, Tatsiana; Klinkby, Esben; Kluth, Stefan; Knecht, Marc; Kneisel, Peter; Ko, In Soo; Ko, Kwok; Kobayashi, Makoto; Kobayashi, Nobuko; Kobel, Michael; Koch, Manuel; Kodys, Peter; Koetz, Uli; Kohrs, Robert; Kojima, Yuuji; Kolanoski, Hermann; Kolodziej, Karol; Kolomensky, Yury G.; Komamiya, Sachio; Kong, Xiang Cheng; Konigsberg, Jacobo; Korbel, Volker; Koscielniak, Shane; Kostromin, Sergey; Kowalewski, Robert; Kraml, Sabine; Krammer, Manfred; Krasnykh, Anatoly; Krautscheid, Thorsten; Krawczyk, Maria; James Krebs, H.; Krempetz, Kurt; Kribs, Graham; Krishnagopal, Srinivas; Kriske, Richard; Kronfeld, Andreas; Kroseberg, Jürgen; Kruchonak, Uladzimir; Kruecker, Dirk; Krüger, Hans; Krumpa, Nicholas A.; Krumshtein, Zinovii; Kuang, Yu Ping; Kubo, Kiyoshi; Kuchler, Vic; Kudoh, Noboru; Kulis, Szymon; Kumada, Masayuki; Kumar, Abhay; Kume, Tatsuya; Kundu, Anirban; Kurevlev, German; Kurihara, Yoshimasa; Kuriki, Masao; Kuroda, Shigeru; Kuroiwa, Hirotoshi; Kurokawa, Shin-ichi; Kusano, Tomonori; Kush, Pradeep K.; Kutschke, Robert; Kuznetsova, Ekaterina; Kvasnicka, Peter; Kwon, Youngjoon; Labarga, Luis; Lacasta, Carlos; Lackey, Sharon; Lackowski, Thomas W.; Lafaye, Remi; Lafferty, George; Lagorio, Eric; Laktineh, Imad; Lal, Shankar; Laloum, Maurice; Lam, Briant; Lancaster, Mark; Lander, Richard; Lange, Wolfgang; Langenfeld, Ulrich; Langeveld, Willem; Larbalestier, David; Larsen, Ray; Lastovicka, Tomas; Lastovicka-Medin, Gordana; Latina, Andrea; Latour, Emmanuel; Laurent, Lisa; Le, Ba Nam; Le, Duc Ninh; Le Diberder, Francois; Dû, Patrick Le; Lebbolo, Hervé; Lebrun, Paul; Lecoq, Jacques; Lee, Sung-Won; Lehner, Frank; Leibfritz, Jerry; Lenkszus, Frank; Lesiak, Tadeusz; Levy, Aharon; Lewandowski, Jim; Leyh, Greg; Li, Cheng; Li, Chong Sheng; Li, Chun Hua; Li, Da Zhang; Li, Gang; Li, Jin; Li, Shao Peng; Li, Wei Ming; Li, Weiguo; Li, Xiao Ping; Li, Xue-Qian; Li, Yuanjing; Li, Yulan; Li, Zenghai; Li, Zhong Quan; Liang, Jian Tao; Liao, Yi; Lilje, Lutz; Guilherme Lima, J.; Lintern, Andrew J.; Lipton, Ronald; List, Benno; List, Jenny; Liu, Chun; Liu, Jian Fei; Liu, Ke Xin; Liu, Li Qiang; Liu, Shao Zhen; Liu, Sheng Guang; Liu, Shubin; Liu, Wanming; Liu, Wei Bin; Liu, Ya Ping; Liu, Yu Dong; Lockyer, Nigel; Logan, Heather E.; Logatchev, Pavel V.; Lohmann, Wolfgang; Lohse, Thomas; Lola, Smaragda; Lopez-Virto, Amparo; Loveridge, Peter; Lozano, Manuel; Lu, Cai-Dian; Lu, Changguo; Lu, Gong-Lu; Lu, Wen Hui; Lubatti, Henry; Lucotte, Arnaud; Lundberg, Björn; Lundin, Tracy; Luo, Mingxing; Luong, Michel; Luth, Vera; Lutz, Benjamin; Lutz, Pierre; Lux, Thorsten; Luzniak, Pawel; Lyapin, Alexey; Lykken, Joseph; Lynch, Clare; Ma, Li; Ma, Lili; Ma, Qiang; Ma, Wen-Gan; Macfarlane, David; Maciel, Arthur; MacLeod, Allan; MacNair, David; Mader, Wolfgang; Magill, Stephen; Magnan, Anne-Marie; Maiheu, Bino; Maity, Manas; Majchrzak, Millicent; Majumder, Gobinda; Makarov, Roman; Makowski, Dariusz; Malaescu, Bogdan; Mallik, C.; Mallik, Usha; Malton, Stephen; Malyshev, Oleg B.; Malysheva, Larisa I.; Mammosser, John; Mamta; Mamuzic, Judita; Manen, Samuel; Manghisoni, Massimo; Manly, Steven; Marcellini, Fabio; Marcisovsky, Michal; Markiewicz, Thomas W.; Marks, Steve; Marone, Andrew; Marti, Felix; Martin, Jean-Pierre; Martin, Victoria; Martin-Chassard, Gisèle; Martinez, Manel; Martinez-Rivero, Celso; Martsch, Dennis; Martyn, Hans-Ulrich; Maruyama, Takashi; Masuzawa, Mika; Mathez, Hervé; Matsuda, Takeshi; Matsumoto, Hiroshi; Matsumoto, Shuji; Matsumoto, Toshihiro; Matsunaga, Hiroyuki; Mättig, Peter; Mattison, Thomas; Mavromanolakis, Georgios; Mawatari, Kentarou; Mazzacane, Anna; McBride, Patricia; McCormick, Douglas; McCormick, Jeremy; McDonald, Kirk T.; McGee, Mike; McIntosh, Peter; McKee, Bobby; McPherson, Robert A.; Meidlinger, Mandi; Meier, Karlheinz; Mele, Barbara; Meller, Bob; Melzer-Pellmann, Isabell-Alissandra; Mendez, Hector; Mercer, Adam; Merkin, Mikhail; Meshkov, I.N.; Messner, Robert; Metcalfe, Jessica; Meyer, Chris; Meyer, Hendrik; Meyer, Joachim; Meyer, Niels; Meyners, Norbert; Michelato, Paolo; Michizono, Shinichiro; Mihalcea, Daniel; Mihara, Satoshi; Mihara, Takanori; Mikami, Yoshinari; Mikhailichenko, Alexander A.; Milardi, Catia; Miller, David J.; Miller, Owen; Miller, Roger J.; Milstene, Caroline; Mimashi, Toshihiro; Minashvili, Irakli; Miquel, Ramon; Mishra, Shekhar; Mitaroff, Winfried; Mitchell, Chad; Miura, Takako; Miyata, Hitoshi; Mjörnmark, Ulf; Mnich, Joachim; Moenig, Klaus; Moffeit, Kenneth; Mokhov, Nikolai; Molloy, Stephen; Monaco, Laura; Monasterio, Paul R.; Montanari, Alessandro; Moon, Sung Ik; Moortgat-Pick, Gudrid A.; Mora de Freitas, Paulo; Morel, Federic; Moretti, Stefano; Morgunov, Vasily; Mori, Toshinori; Morin, Laurent; Morisseau, François; Morita, Yoshiyuki; Morita, Youhei; Morita, Yuichi; Morozov, Nikolai; Morozumi, Yuichi; Morse, William; Moser, Hans-Guenther; Moultaka, Gilbert; Mtingwa, Sekazi; Mudrinic, Mihajlo; Mueller, Alex; Mueller, Wolfgang; Muennich, Astrid; Muhlleitner, Milada Margarete; Mukherjee, Bhaskar; Mukhopadhyaya, Biswarup; Müller, Thomas; Munro, Morrison; Murayama, Hitoshi; Muto, Toshiya; Myneni, Ganapati Rao; Nabhiraj, P.Y.; Nagaitsev, Sergei; Nagamine, Tadashi; Nagano, Ai; Naito, Takashi; Nakai, Hirotaka; Nakajima, Hiromitsu; Nakamura, Isamu; Nakamura, Tomoya; Nakanishi, Tsutomu; Nakao, Katsumi; Nakao, Noriaki; Nakayoshi, Kazuo; Nam, Sang; Namito, Yoshihito; Namkung, Won; Nantista, Chris; Napoly, Olivier; Narain, Meenakshi; Naroska, Beate; Nauenberg, Uriel; Nayyar, Ruchika; Neal, Homer; Nelson, Charles; Nelson, Janice; Nelson, Timothy; Nemecek, Stanislav; Neubauer, Michael; Neuffer, David; Newman, Myriam Q.; Nezhevenko, Oleg; Ng, Cho-Kuen; Nguyen, Anh Ky; Nguyen, Minh; Van Nguyen Thi,Hong; Niebuhr, Carsten; Niehoff, Jim; Niezurawski, Piotr; Nishitani, Tomohiro; Nitoh, Osamu; Noguchi, Shuichi; Nomerotski, Andrei; Noonan, John; Norbeck, Edward; Nosochkov, Yuri; Notz, Dieter; Nowak, Grazyna; Nowak, Hannelies; Noy, Matthew; Nozaki, Mitsuaki; Nyffeler, Andreas; Nygren, David; Oddone, Piermaria; O'Dell, Joseph; Oh, Jong-Seok; Oh, Sun Kun; Ohkuma, Kazumasa; Ohlerich, Martin; Ohmi, Kazuhito; Ohnishi, Yukiyoshi; Ohsawa, Satoshi; Ohuchi, Norihito; Oide, Katsunobu; Okada, Nobuchika; Okada, Yasuhiro; Okamura, Takahiro; Okugi, Toshiyuki; Okumi, Shoji; Okumura, Ken-ichi; Olchevski, Alexander; Oliver, William; Olivier, Bob; Olsen, James; Olsen, Jeff; Olsen, Stephen; Olshevsky, A.G.; Olsson, Jan; Omori, Tsunehiko; Onel, Yasar; Onengut, Gulsen; Ono, Hiroaki; Onoprienko, Dmitry; Oreglia, Mark; Oren, Will; Orimoto, Toyoko J.; Oriunno, Marco; Orlandea, Marius Ciprian; Oroku, Masahiro; Orr, Lynne H.; Orr, Robert S.; Oshea, Val; Oskarsson, Anders; Osland, Per; Ossetski, Dmitri; Österman, Lennart; Ostiguy, Francois; Otono, Hidetoshi; Ottewell, Brian; Ouyang, Qun; Padamsee, Hasan; Padilla, Cristobal; Pagani, Carlo; Palmer, Mark A.; Pam, Wei Min; Pande, Manjiri; Pande, Rajni; Pandit, V.S.; Pandita, P.N.; Pandurovic, Mila; Pankov, Alexander; Panzeri, Nicola; Papandreou, Zisis; Paparella, Rocco; Para, Adam; Park, Hwanbae; Parker, Brett; Parkes, Chris; Parma, Vittorio; Parsa, Zohreh; Parsons, Justin; Partridge, Richard; Pasquinelli, Ralph; Pásztor, Gabriella; Paterson, Ewan; Patrick, Jim; Patteri, Piero; Ritchie Patterson, J.; Pauletta, Giovanni; Paver, Nello; Pavlicek, Vince; Pawlik, Bogdan; Payet, Jacques; Pchalek, Norbert; Pedersen, John; Pei, Guo Xi; Pei, Shi Lun; Pelka, Jerzy; Pellegrini, Giulio; Pellett, David; Peng, G.X.; Penn, Gregory; Penzo, Aldo; Perry, Colin; Peskin, Michael; Peters, Franz; Petersen, Troels Christian; Peterson, Daniel; Peterson, Thomas; Petterson, Maureen; Pfeffer, Howard; Pfund, Phil; Phelps, Alan; Van Phi, Quang; Phillips, Jonathan; Phinney, Nan; Piccolo, Marcello; Piemontese, Livio; Pierini, Paolo; Thomas Piggott, W.; Pike, Gary; Pillet, Nicolas; Jayawardena, Talini Pinto; Piot, Phillippe; Pitts, Kevin; Pivi, Mauro; Plate, Dave; Pleier, Marc-Andre; Poblaguev, Andrei; Poehler, Michael; Poelker, Matthew; Poffenberger, Paul; Pogorelsky, Igor; Poirier, Freddy; Poling, Ronald; Poole, Mike; Popescu, Sorina; Popielarski, John; Pöschl, Roman; Postranecky, Martin; Potukochi, Prakash N.; Prast, Julie; Prat, Serge; Preger, Miro; Prepost, Richard; Price, Michael; Proch, Dieter; Puntambekar, Avinash; Qin, Qing; Qu, Hua Min; Quadt, Arnulf; Quesnel, Jean-Pierre; Radeka, Veljko; Rahmat, Rahmat; Rai, Santosh Kumar; Raimondi, Pantaleo; Ramberg, Erik; Ranjan, Kirti; Rao, Sista V.L.S.; Raspereza, Alexei; Ratti, Alessandro; Ratti, Lodovico; Raubenheimer, Tor; Raux, Ludovic; Ravindran, V.; Raychaudhuri, Sreerup; Re, Valerio; Rease, Bill; Reece, Charles E.; Regler, Meinhard; Rehlich, Kay; Reichel, Ina; Reichold, Armin; Reid, John; Reid, Ron; Reidy, James; Reinhard, Marcel; Renz, Uwe; Repond, Jose; Resta-Lopez, Javier; Reuen, Lars; Ribnik, Jacob; Rice, Tyler; Richard, François; Riemann, Sabine; Riemann, Tord; Riles, Keith; Riley, Daniel; Rimbault, Cécile; Rindani, Saurabh; Rinolfi, Louis; Risigo, Fabio; Riu, Imma; Rizhikov, Dmitri; Rizzo, Thomas; Rochford, James H.; Rodriguez, Ponciano; Roeben, Martin; Rolandi, Gigi; Roodman, Aaron; Rosenberg, Eli; Roser, Robert; Ross, Marc; Rossel, François; Rossmanith, Robert; Roth, Stefan; Rougé, André; Rowe, Allan; Roy, Amit; Roy, Sendhunil B.; Roy, Sourov; Royer, Laurent; Royole-Degieux, Perrine; Royon, Christophe; Ruan, Manqi; Rubin, David; Ruehl, Ingo; Jimeno, Alberto Ruiz; Ruland, Robert; Rusnak, Brian; Ryu, Sun-Young; Sabbi, Gian Luca; Sadeh, Iftach; Sadygov, Ziraddin Y; Saeki, Takayuki; Sagan, David; Sahni, Vinod C.; Saini, Arun; Saito, Kenji; Saito, Kiwamu; Sajot, Gerard; Sakanaka, Shogo; Sakaue, Kazuyuki; Salata, Zen; Salih, Sabah; Salvatore, Fabrizio; Samson, Joergen; Sanami, Toshiya; Levi Sanchez, Allister; Sands, William; Santic, John; Sanuki, Tomoyuki; Sapronov, Andrey; Sarkar, Utpal; Sasao, Noboru; Satoh, Kotaro; Sauli, Fabio; Saunders, Claude; Saveliev, Valeri; Savoy-Navarro, Aurore; Sawyer, Lee; Saxton, Laura; Schäfer, Oliver; Schälicke, Andreas; Schade, Peter; Schaetzel, Sebastien; Scheitrum, Glenn; Schibler, Emilie; Schindler, Rafe; Schlösser, Markus; Schlueter, Ross D.; Schmid, Peter; Schmidt, Ringo Sebastian; Schneekloth, Uwe; Schreiber, Heinz Juergen; Schreiber, Siegfried; Schroeder, Henning; Peter Schüler, K.; Schulte, Daniel; Schultz-Coulon, Hans-Christian; Schumacher, Markus; Schumann, Steffen; Schumm, Bruce A.; Schwienhorst, Reinhard; Schwierz, Rainer; Scott, Duncan J.; Scuri, Fabrizio; Sefkow, Felix; Sefri, Rachid; Seguin-Moreau, Nathalie; Seidel, Sally; Seidman, David; Sekmen, Sezen; Seletskiy, Sergei; Senaha, Eibun; Senanayake, Rohan; Sendai, Hiroshi; Sertore, Daniele; Seryi, Andrei; Settles, Ronald; Sever, Ramazan; Shales, Nicholas; Shao, Ming; Shelkov, G.A.; Shepard, Ken; Shepherd-Themistocleous, Claire; Sheppard, John C.; Shi, Cai Tu; Shidara, Tetsuo; Shim, Yeo-Jeong; Shimizu, Hirotaka; Shimizu, Yasuhiro; Shimizu, Yuuki; Shimogawa, Tetsushi; Shin, Seunghwan; Shioden, Masaomi; Shipsey, Ian; Shirkov, Grigori; Shishido, Toshio; Shivpuri, Ram K.; Shrivastava, Purushottam; Shulga, Sergey; Shumeiko, Nikolai; Shuvalov, Sergey; Si, Zongguo; Siddiqui, Azher Majid; Siegrist, James; Simon, Claire; Simrock, Stefan; Sinev, Nikolai; Singh, Bhartendu K.; Singh, Jasbir; Singh, Pitamber; Singh, R.K.; Singh, S.K.; Singini, Monito; Sinha, Anil K.; Sinha, Nita; Sinha, Rahul; Sinram, Klaus; Sissakian, A.N.; Skachkov, N.B.; Skrinsky, Alexander; Slater, Mark; Slominski, Wojciech; Smiljanic, Ivan; Smith, A J Stewart; Smith, Alex; Smith, Brian J.; Smith, Jeff; Smith, Jonathan; Smith, Steve; Smith, Susan; Smith, Tonee; Neville Snodgrass, W.; Sobloher, Blanka; Sohn, Young-Uk; Solidum, Ruelson; Solyak, Nikolai; Son, Dongchul; Sonmez, Nasuf; Sopczak, Andre; Soskov, V.; Spencer, Cherrill M.; Spentzouris, Panagiotis; Speziali, Valeria; Spira, Michael; Sprehn, Daryl; Sridhar, K.; Srivastava, Asutosh; St. Lorant, Steve; Stahl, Achim; Stanek, Richard P.; Stanitzki, Marcel; Stanley, Jacob; Stefanov, Konstantin; Stein, Werner; Steiner, Herbert; Stenlund, Evert; Stern, Amir; Sternberg, Matt; Stockinger, Dominik; Stockton, Mark; Stoeck, Holger; Strachan, John; Strakhovenko, V.; Strauss, Michael; Striganov, Sergei I.; Strologas, John; Strom, David; Strube, Jan; Stupakov, Gennady; Su, Dong; Sudo, Yuji; Suehara, Taikan; Suehiro, Toru; Suetsugu, Yusuke; Sugahara, Ryuhei; Sugimoto, Yasuhiro; Sugiyama, Akira; Suh, Jun Suhk; Sukovic, Goran; Sun, Hong; Sun, Stephen; Sun, Werner; Sun, Yi; Sun, Yipeng; Suszycki, Leszek; Sutcliffe, Peter; Suthar, Rameshwar L.; Suwada, Tsuyoshi; Suzuki, Atsuto; Suzuki, Chihiro; Suzuki, Shiro; Suzuki, Takashi; Swent, Richard; Swientek, Krzysztof; Swinson, Christina; Syresin, Evgeny; Szleper, Michal; Tadday, Alexander; Takahashi, Rika; Takahashi, Tohru; Takano, Mikio; Takasaki, Fumihiko; Takeda, Seishi; Takenaka, Tateru; Takeshita, Tohru; Takubo, Yosuke; Tanaka, Masami; Tang, Chuan Xiang; Taniguchi, Takashi; Tantawi, Sami; Tapprogge, Stefan; Tartaglia, Michael A.; Tassielli, Giovanni Francesco; Tauchi, Toshiaki; 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Valishev, Alex; Vamra, Raghava; Van der Graaf, Harry; Van Kooten, Rick; Van Zandbergen, Gary; Vanel, Jean-Charles; Variola, Alessandro; Varner, Gary; Velasco, Mayda; Velte, Ulrich; Velthuis, Jaap; Vempati, Sundir K.; Venturini, Marco; Vescovi, Christophe; Videau, Henri; Vila, Ivan; Vincent, Pascal; Virey, Jean-Marc; Visentin, Bernard; Viti, Michele; Vo, Thanh Cuong; Vogel, Adrian; Vogt, Harald; von Toerne, Eckhard; Vorozhtsov, S.B.; Vos, Marcel; Votava, Margaret; Vrba, Vaclav; Wackeroth, Doreen; Wagner, Albrecht; Wagner, Carlos E.M.; Wagner, Stephen; Wake, Masayoshi; Walczak, Roman; Walker, Nicholas J.; Walkowiak, Wolfgang; Wallon, Samuel; Walsh, Roberval; Walston, Sean; Waltenberger, Wolfgang; Walz, Dieter; Wang, Chao En; Wang, Chun Hong; Wang, Dou; Wang, Faya; Wang, Guang Wei; Wang, Haitao; Wang, Jiang; Wang, Jiu Qing; Wang, Juwen; Wang, Lanfa; Wang, Lei; Wang, Min-Zu; Wang, Qing; Wang, Shu Hong; Wang, Xiaolian; Wang, Xue-Lei; Wang, Yi Fang; Wang, Zheng; Wanzenberg, Rainer; Ward, Bennie; Ward, David; Warmbein, Barbara; Warner, David W.; Warren, Matthew; Washio, Masakazu; Watanabe, Isamu; Watanabe, Ken; Watanabe, Takashi; Watanabe, Yuichi; Watson, Nigel; Wattimena, Nanda; Wayne, Mitchell; Weber, Marc; Weerts, Harry; Weiglein, Georg; Weiland, Thomas; Weinzierl, Stefan; Weise, Hans; Weisend, John; Wendt, Manfred; Wendt, Oliver; Wenzel, Hans; Wenzel, William A.; Wermes, Norbert; Werthenbach, Ulrich; Wesseln, Steve; Wester, William; White, Andy; White, Glen R.; Wichmann, Katarzyna; Wienemann, Peter; Wierba, Wojciech; Wilksen, Tim; Willis, William; Wilson, Graham W.; Wilson, John A.; Wilson, Robert; Wing, Matthew; Winter, Marc; Wirth, Brian D.; Wolbers, Stephen A.; Wolff, Dan; Wolski, Andrzej; Woodley, Mark D.; Woods, Michael; Woodward, Michael L.; Woolliscroft, Timothy; Worm, Steven; Wormser, Guy; Wright, Dennis; Wright, Douglas; Wu, Andy; Wu, Tao; Wu, Yue Liang; Xella, Stefania; Xia, Guoxing; Xia, Lei; Xiao, Aimin; Xiao, Liling; Xie, Jia Lin; Xing, Zhi-Zhong; Xiong, Lian You; Xu, Gang; Xu, Qing Jing; Yajnik, Urjit A.; Yakimenko, Vitaly; Yamada, Ryuji; Yamaguchi, Hiroshi; Yamamoto, Akira; Yamamoto, Hitoshi; Yamamoto, Masahiro; Yamamoto, Naoto; Yamamoto, Richard; Yamamoto, Yasuchika; Yamanaka, Takashi; Yamaoka, Hiroshi; Yamashita, Satoru; Yamazaki, Hideki; Yan, Wenbiao; Yang, Hai-Jun; Yang, Jin Min; Yang, Jongmann; Yang, Zhenwei; Yano, Yoshiharu; Yazgan, Efe; Yeh, G.P.; Yilmaz, Hakan; Yock, Philip; Yoda, Hakutaro; Yoh, John; Yokoya, Kaoru; Yokoyama, Hirokazu; York, Richard C.; Yoshida, Mitsuhiro; Yoshida, Takuo; Yoshioka, Tamaki; Young, Andrew; Yu, Cheng Hui; Yu, Jaehoon; Yu, Xian Ming; Yuan, Changzheng; Yue, Chong-Xing; Yue, Jun Hui; Zacek, Josef; Zagorodnov, Igor; Zalesak, Jaroslav; Zalikhanov, Boris; Zarnecki, Aleksander Filip; Zawiejski, Leszek; Zeitnitz, Christian; Zeller, Michael; Zerwas, Dirk; Zerwas, Peter; Zeyrek, Mehmet; Zhai, Ji Yuan; Zhang, Bao Cheng; Zhang, Bin; Zhang, Chuang; Zhang, He; Zhang, Jiawen; Zhang, Jing; Zhang, Jing Ru; Zhang, Jinlong; Zhang, Liang; Zhang, X.; Zhang, Yuan; Zhang, Zhige; Zhang, Zhiqing; Zhang, Ziping; Zhao, Haiwen; Zhao, Ji Jiu; Zhao, Jing Xia; Zhao, Ming Hua; Zhao, Sheng Chu; Zhao, Tianchi; Zhao, Tong Xian; Zhao, Zhen Tang; Zhao, Zhengguo; Zhou, De Min; Zhou, Feng; Zhou, Shun; Zhu, Shou Hua; Zhu, Xiong Wei; Zhukov, Valery; Zimmermann, Frank; Ziolkowski, Michael; Zisman, Michael S.; Zomer, Fabian; Zong, Zhang Guo; Zorba, Osman; Zutshi, Vishnu

2007-01-01

This report, Volume IV of the International Linear Collider Reference Design Report, describes the detectors which will record and measure the charged and neutral particles produced in the ILC's high energy e+e- collisions. The physics of the ILC, and the environment of the machine-detector interface, pose new challenges for detector design. Several conceptual designs for the detector promise the needed performance, and ongoing detector R&D is addressing the outstanding technological issues. Two such detectors, operating in push-pull mode, perfectly instrument the ILC interaction region, and access the full potential of ILC physics.

Emerging applications for vertical cavity surface emitting lasers

International Nuclear Information System (INIS)

Harris, J S; O'sullivan, T; Sarmiento, T; Lee, M M; Vo, S

2011-01-01

Vertical cavity surface emitting lasers (VCSELs) emitting at 850 nm have experienced explosive growth in the past decade because of their many attractive optical features and incredibly low-cost manufacturability. This review reviews the foundations for GaAs-based VCSEL technology as well as the materials and device challenges to extend the operating wavelength to both shorter and longer wavelengths. We discuss some of the applications that are enabled by the integration of VCSELs with both active and passive semiconductor elements for telecommunications, both in vivo and in vitro biosensing, high-density optical storage and imaging at wavelengths much less than the diffraction limit of light

Simulations of the ILC Electron Gun and Electron Bunching System

International Nuclear Information System (INIS)

Haakonsen, C.B.; McGill U.

2006-01-01

The International Linear Collider (ILC) is a proposed electron-positron collider, expected to provide insight into important questions in particle physics. A part of the global R and D effort for the ILC is the design of its electron gun and electron bunching system. The present design of the bunching system has two sub-harmonic bunchers, one operating at 108 MHz and one at 433MHz, and two 5-cell 1.3 GHz (L-band) bunchers. This bunching system has previously been simulated using the Phase and Radial Motion in Electron Linear Accelerators (PARMELA) software, and those simulations indicated that the design provides sufficient bunching and acceleration. Due to the complicated dynamics governing the electrons in the bunching system we decided to verify and expand the PARMELA results using the more recent and independent simulation software General Particle Tracer (GPT). GPT tracks the motion and interactions of a set of macro particles, each of which represent a number of electrons, and provides a variety of analysis capabilities. To provide initial conditions for the macro particles, a method was developed for deriving the initial conditions from detailed simulations of particle trajectories in the electron gun. These simulations were performed using the Egun software. For realistic simulation of the L-band bunching cavities, their electric and magnetic fields were calculated using the Superfish software and imported into GPT. The GPT simulations arrived at similar results to the PARMELA simulations for sub-harmonic bunching. However, using GPT it was impossible to achieve an efficient bunching performance of the first L-band bunching cavity. To correct this, the first L-band buncher cell was decoupled from the remaining 4 cells and driven as an independent cavity. Using this modification we attained results similar to the PARMELA simulations. Although the modified bunching system design performed as required, the modifications are technically challenging to implement

Ultrafast directional beam switching in coupled vertical-cavity surface-emitting lasers

International Nuclear Information System (INIS)

Ning, C. Z.; Goorjian, P.

2001-01-01

We propose a strategy to performing ultrafast directional beam switching using two coupled vertical-cavity surface-emitting lasers (VCSELs). The proposed strategy is demonstrated for two VCSELs of 5.6 μm in diameter placed about 1 μm apart from the edges, showing a switching speed of 42 GHz with a maximum far-field angle span of about 10 degree. [copyright] 2001 American Institute of Physics

1.3 GHz superconducting RF cavity program at Fermilab

Energy Technology Data Exchange (ETDEWEB)

Ginsburg, C.M.; Arkan, T.; Barbanotti, S.; Carter, H.; Champion, M.; Cooley, L.; Cooper, C.; Foley, M.; Ge, M.; Grimm, C.; Harms, E.; /Fermilab

2011-03-01

At Fermilab, 9-cell 1.3 GHz superconducting RF (SRF) cavities are prepared, qualified, and assembled into cryomodules (CMs) for Project X, an International Linear Collider (ILC), or other future projects. The 1.3 GHz SRF cavity program includes targeted R&D on 1-cell 1.3 GHz cavities for cavity performance improvement. Production cavity qualification includes cavity inspection, surface processing, clean assembly, and one or more cryogenic low-power CW qualification tests which typically include performance diagnostics. Qualified cavities are welded into helium vessels and are cryogenically tested with pulsed high-power. Well performing cavities are assembled into cryomodules for pulsed high-power testing in a cryomodule test facility, and possible installation into a beamline. The overall goals of the 1.3 GHz SRF cavity program, supporting facilities, and accomplishments are described.

The ILC control system

International Nuclear Information System (INIS)

Carwardine, J.; Saunders, C.; Arnold, N.; Lenkszus, F.; Rehlich, K.; Simrock, S.; Banerjee, b.; Chase, B.; Gottschalk, E.; Joireman, P.; Kasley, P.; Lackey, S.; McBride, P.; Pavlicek, V.; Patrick, J.; Votava, M.; Wolbers, S.; Furukawa, K.; Michizono, S.; Larson, R.S.; Downing, R.

2007-01-01

Since the last ICALEPCS, a small multi-region team has developed a reference design model for a control system for the International Linear Collider as part of the ILC Global Design Effort. The scale and performance parameters of the ILC accelerator require new thinking in regards to control system design. Technical challenges include the large number of accelerator systems to be controlled, the large scale of the accelerator facility, the high degree of automation needed during accelerator operations, and control system equipment requiring 'Five Nines' availability. The R and D path for high availability touches the control system hardware, software, and overall architecture, and extends beyond traditional interfaces into the technical systems. Software considerations for HA include fault detection through exhaustive out-of-band monitoring and automatic state migration to redundant systems, while the telecom industry's emerging ATCA standard - conceived, specified, and designed for High Availability - is being evaluated for suitability for ILC front-end electronics.

Development of high gradient superconducting radio frequency cavities for international linear collider and energy recovery linear accelerator

International Nuclear Information System (INIS)

Saito, Kenji; Furuta, Fumio; Saeki, Takayuki

2009-01-01

Superconducting radio frequency (SRF) cavities were used for storage rings like TRISTAN at KEK, HERA at DESY and LEP-II at CERN in 1990-2000. This technology has been accepted as a common accelerator technology. In August 2004, ITPR recommended an electron/positron linear collider based on SRF technology for the future high energy physics. ICFA accepted the recommendation and named it ILC (International Linear Collider). SRF cavities have a very unique feature due to its very small surface resistance. Energy recovery is another very exciting application. Many laboratories are proposing ERL (Energy Recovery LINAC) as a next bright photon source. In these accelerators, production of SRF cavities with reliably high performance is the most important issue. In this paper the activities of ILC high gradient cavities will be introduced. ERL activity will be briefly presented. (author)

Development of High Gradient Superconducting Radio Frequency Cavities for International Linear Collider and Energy Recovery Linear Accelerator

Science.gov (United States)

Saito, Kenji; Furuta, Fumio; Saeki, Takayuki

Superconducting radio frequency (SRF) cavities were used for storage rings like TRISTAN at KEK, HERA at DESY and LEP-II at CERN in 1990-2000. This technology has been accepted as a common accelerator technology. In August 2004, ITPR recommended an electron/positron linear collider based on SRF technology for the future high energy physics. ICFA accepted the recommendation and named it ILC (International Linear Collider). SRF cavities have a very unique feature due to its very small surface resistance. Energy recovery is another very exciting application. Many laboratories are proposing ERL (Energy Recovery LINAC) as a next bright photon source. In these accelerators, production of SRF cavities with reliably high performance is the most important issue. In this paper the activities of ILC high gradient cavities will be introduced. ERL activity will be briefly presented.

Spin-controlled ultrafast vertical-cavity surface-emitting lasers

Science.gov (United States)

Höpfner, Henning; Lindemann, Markus; Gerhardt, Nils C.; Hofmann, Martin R.

2014-05-01

Spin-controlled semiconductor lasers are highly attractive spintronic devices providing characteristics superior to their conventional purely charge-based counterparts. In particular, spin-controlled vertical-cavity surface emitting lasers (spin-VCSELs) promise to offer lower thresholds, enhanced emission intensity, spin amplification, full polarization control, chirp control and ultrafast dynamics. Most important, the ability to control and modulate the polarization state of the laser emission with extraordinarily high frequencies is very attractive for many applications like broadband optical communication and ultrafast optical switches. We present a novel concept for ultrafast spin-VCSELs which has the potential to overcome the conventional speed limitation for directly modulated lasers by the relaxation oscillation frequency and to reach modulation frequencies significantly above 100 GHz. The concept is based on the coupled spin-photon dynamics in birefringent micro-cavity lasers. By injecting spin-polarized carriers in the VCSEL, oscillations of the coupled spin-photon system can by induced which lead to oscillations of the polarization state of the laser emission. These oscillations are decoupled from conventional relaxation oscillations of the carrier-photon system and can be much faster than these. Utilizing these polarization oscillations is thus a very promising approach to develop ultrafast spin-VCSELs for high speed optical data communication in the near future. Different aspects of the spin and polarization dynamics, its connection to birefringence and bistability in the cavity, controlled switching of the oscillations, and the limitations of this novel approach will be analysed theoretically and experimentally for spin-polarized VCSELs at room temperature.

Effect of cathode shape on vertical buffered electropolishing for niobium SRF cavities

Science.gov (United States)

Jin, S.; Wu, A. T.; Lu, X. Y.; Rimmer, R. A.; Lin, L.; Zhao, K.; Mammosser, J.; Gao, J.

2013-09-01

This paper reports the research results of the effect of cathode shape during vertical buffered electropolishing (BEP) by employing a demountable single cell niobium (Nb) superconducting radio frequency (SRF) cavity. Several different cathode shapes such as, for instance, bar, ball, ellipsoid, and wheels of different diameters have been tested. Detailed electropolishing parameters including I-V characteristic, removal rate, surface roughness, and polishing uniformity at different locations inside the demountable cavity are measured. Similar studies are also done on conventional electropolishing (EP) for comparison. It is revealed that cathode shape has dominant effects for BEP especially on the obtaining of a suitable polishing condition and a uniform polishing rate in an Nb SRF single cell cavity. EP appears to have the same tendency. This paper demonstrates that a more homogeneous polishing result can be obtained by optimizing the electric field distribution inside the cavity through the modification of the cathode shape given the conditions that temperature and electrolyte flow are kept constant. Electric field distribution and electrolyte flow patterns inside the cavity are simulated via Poisson-Superfish and Solidworks respectively. With the optimal cathode shape, BEP shows a much faster polishing rate of ∼2.5 μm/min and is able to produce a smoother surface finish in the treatments of single cell cavities in comparison with EP.

Effect of cathode shape on vertical buffered electropolishing for niobium SRF cavities

International Nuclear Information System (INIS)

Jin, S.; Wu, A.T.; Lu, X.Y.; Rimmer, R.A.; Lin, L.; Zhao, K.; Mammosser, J.; Gao, J.

2013-01-01

This paper reports the research results of the effect of cathode shape during vertical buffered electropolishing (BEP) by employing a demountable single cell niobium (Nb) superconducting radio frequency (SRF) cavity. Several different cathode shapes such as, for instance, bar, ball, ellipsoid, and wheels of different diameters have been tested. Detailed electropolishing parameters including I–V characteristic, removal rate, surface roughness, and polishing uniformity at different locations inside the demountable cavity are measured. Similar studies are also done on conventional electropolishing (EP) for comparison. It is revealed that cathode shape has dominant effects for BEP especially on the obtaining of a suitable polishing condition and a uniform polishing rate in an Nb SRF single cell cavity. EP appears to have the same tendency. This paper demonstrates that a more homogeneous polishing result can be obtained by optimizing the electric field distribution inside the cavity through the modification of the cathode shape given the conditions that temperature and electrolyte flow are kept constant. Electric field distribution and electrolyte flow patterns inside the cavity are simulated via Poisson–Superfish and Solidworks respectively. With the optimal cathode shape, BEP shows a much faster polishing rate of ∼2.5 μm/min and is able to produce a smoother surface finish in the treatments of single cell cavities in comparison with EP.

Connecting LHC, ILC, and quintessence

International Nuclear Information System (INIS)

Chung, Daniel J.H.; Everett, Lisa L.; Kong, Kyoungchul; Matchev, Konstantin T.

2007-01-01

If the cold dark matter consists of weakly interacting massive particles (WIMPs), anticipated measurements of the WIMP properties at the Large Hadron Collider (LHC) and the International Linear Collider (ILC) will provide an unprecedented experimental probe of cosmology at temperatures of order 1 GeV. It is worth emphasizing that the expected outcome of these tests may or may not be consistent with the picture of standard cosmology. For example, in kination-dominated quintessence models of dark energy, the dark matter relic abundance can be significantly enhanced compared to that obtained from freeze out in a radiation-dominated universe. Collider measurements then will simultaneously probe both dark matter and dark energy. In this article, we investigate the precision to which the LHC and ILC can determine the dark matter and dark energy parameters under those circumstances. We use an illustrative set of four benchmark points in minimal supergravity in analogy with the four LCC benchmark points. The precision achievable together at the LHC and ILC is sufficient to discover kination-dominated quintessence, under the assumption that the WIMPs are the only dark matter component. The LHC and ILC can thus play important roles as alternative probes of both dark matter and dark energy

Research and development for electropolishing of Nb for ILC accelerator cavities

International Nuclear Information System (INIS)

Kelley, Michael J.

2009-01-01

The objectives of this project are to 1, Expand the scientific and technological understanding of the effect of post-treatment (electropolish, buffered chemical polish, low-temperature baking) on the surface of niobium; 2, Relate the knowledge to the performance of niobium superconducting radiofrequency accelerator cavities; and, 3, Thereby design and demonstrate an electropolish process that can be applied to complete cavities

Dark current and radiation shielding studies for the ILC main linac

Energy Technology Data Exchange (ETDEWEB)

Mokhov, Nikolai V. [Fermilab; Rakhno, I. L. [Fermilab; Solyak, N. A. [Fermilab; Sukhanov, A. [Fermilab; Tropin, I. S. [Fermilab

2016-12-05

Electrons of dark current (DC), generated in high-gradient superconducting RF cavities (SRF) due to field emission, can be accelerated up to very high energies—19 GeV in the case of the International Linear Collider (ILC) main linac—before they are removed by focusing and steering magnets. Electromagnetic and hadron showers generated by such electrons can represent a significant radiation threat to the linac equipment and personnel. In our study, an operational scenario is analysed which is believed can be considered as the worst case scenario for the main linac regarding the DC contribution to the radiation environment in the main linac tunnel. A detailed modelling is performed for the DC electrons which are emitted from the surface of the SRF cavities and can be repeatedly accelerated in the high-gradient fields in many SRF cavities. Results of MARS15 Monte Carlo calculations, performed for the current main linac tunnel design, reveal that the prompt dose design level of 25 μSv/hr in the service tunnel can be provided by a 2.3-m thick concrete wall between the main and service ls.

Development of superconducting cavities at JAERI

International Nuclear Information System (INIS)

Ouchi, N.

2001-01-01

Development of superconducting (SC) cavities is continued for the high intensity proton accelerator in JAERI. In FY-1999, we carried out R and D work; (1) 2nd vertical test of β=0.886 single-cell cavity, (2) vertical test for observation of Q-disease without heat treatment after electropolishing, (3) vertical test of β=0.5 5-cell cavity, (4) pretuning, surface treatment and vertical test of β=0.886 5-cell cavity, (5) pulsed operation of β=0.886 single-cell cavity in the vertical test to confirm the validity of a new model calculation. This paper describes the present status of the R and D work for the SC cavities in JAERI. (author)

Study for ILC Damping Ring at KEKB

Energy Technology Data Exchange (ETDEWEB)

Flanagan, J.W.; Fukuma, H.; Kanazawa, K.I.; Koiso, H.; Masuzawa, M.; Ohmi, Kazuhito; Ohnishi, Y.; Oide, Katsunobu; Suetsugu, Y.; Tobiyama, M.; /KEK, Tsukuba; Pivi, M.; /SLAC

2011-11-04

ILC damping ring consists of very low emittance electron and positron storage rings. It is necessary for ILC damping ring to study electron cloud effects in such low emittance positron ring. We propose a low emittance operation of KEKB to study the effects.

Investigations on helicoflex gaskets for ILC cavity flanges

International Nuclear Information System (INIS)

Budagov, Yu.; Sisakyan, A.; Shirkov, G.; Sukhanova, A.; Trubnikov, G.; Basti, A.; Bedeschi, F.; Ragonesi, A.; Kephart, R.; Mitchell

2010-01-01

A reliable joint of the Nb superconducting cavities is achieved due to the use of the conical Nb-Ti flanges together with a quick disconnect system (from the Garlock company). The joint was tested at room temperature and liquid nitrogen temperature (77 K), the measured leak level is -9 mbar·1/s. This flange assembly simplifies the design, reduces the assembly time by an order of magnitude, and is expected to decrease the accelerator vacuum chamber length

ILC3 GM-CSF production and mobilisation orchestrate acute intestinal inflammation.

Science.gov (United States)

Pearson, Claire; Thornton, Emily E; McKenzie, Brent; Schaupp, Anna-Lena; Huskens, Nicky; Griseri, Thibault; West, Nathaniel; Tung, Sim; Seddon, Benedict P; Uhlig, Holm H; Powrie, Fiona

2016-01-18

Innate lymphoid cells (ILCs) contribute to host defence and tissue repair but can induce immunopathology. Recent work has revealed tissue-specific roles for ILCs; however, the question of how a small population has large effects on immune homeostasis remains unclear. We identify two mechanisms that ILC3s utilise to exert their effects within intestinal tissue. ILC-driven colitis depends on production of granulocyte macrophage-colony stimulating factor (GM-CSF), which recruits and maintains intestinal inflammatory monocytes. ILCs present in the intestine also enter and exit cryptopatches in a highly dynamic process. During colitis, ILC3s mobilize from cryptopatches, a process that can be inhibited by blocking GM-CSF, and mobilization precedes inflammatory foci elsewhere in the tissue. Together these data identify the IL-23R/GM-CSF axis within ILC3 as a key control point in the accumulation of innate effector cells in the intestine and in the spatio-temporal dynamics of ILCs in the intestinal inflammatory response.

Physics at international linear collider (ILC)

International Nuclear Information System (INIS)

Yamamoto, Hitoshi

2007-01-01

International Linear Collider (ILC) is an electron-positron collider with the initial center-of-mass energy of 500 GeV which is upgradable to about 1 TeV later on. Its goal is to study the physics at TeV scale with unprecedented high sensitivities. The main topics include precision measurements of the Higgs particle properties, studies of supersymmetric particles and the underlying theoretical structure if supersymmetry turns out to be realized in nature, probing alternative possibilities for the origin of mass, and the cosmological connections thereof. In many channels, Higgs and leptonic sector in particular, ILC is substantially more sensitive than LHC, and is complementary to LHC overall. In this short article, we will have a quick look at the capabilities of ILC. (author)

Acetone vapor sensing using a vertical cavity surface emitting laser diode coated with polystyrene

DEFF Research Database (Denmark)

Ansbæk, Thor; Nielsen, Claus Højgaard; Larsen, Niels Bent

2009-01-01

We report theoretical and experimental on a new vapor sensor, using a single-mode vertical-cavity surface-emitting laser (VCSEL) coated with a polymer sensor coating, which can detect acetone vapor at a volume fraction of 2.5%. The sensor provides the advantage of standard packaging, small form...

First results with prototype ISIS devices for ILC vertex detector

International Nuclear Information System (INIS)

Damerell, C.; Zhang, Z.; Gao, R.; John John, Jaya; Li, Y.; Nomerotski, A.; Holland, A.; Seabroke, G.; Havranek, M.; Stefanov, K.; Kar-Roy, A.; Bell, R.; Burt, D.; Pool, P.

2010-01-01

The vertex detectors at the International Linear Collider (ILC) (there will be two of them, one for each of two general purpose detectors) will certainly be built with silicon pixel detectors, either monolithic or perhaps vertically integrated. However, beyond this general statement, there is a wide range of options supported by active R and D programmes all over the world. Pixel-based vertex detectors build on the experience at the SLAC large detector (SLD) operating at the SLAC linear collider (SLC), where a 307 Mpixel detector permitted the highest physics performance at LEP or SLC. For ILC, machine conditions demand much faster readout than at SLC, something like 20 time slices during the 1 ms bunch train. The approach of the image sensor with in-situ storage (ISIS) is unique in offering this capability while avoiding the undesirable requirement of 'pulsed power'. First results from a prototype device that approaches the pixel size of 20 μm square, needed for physics, are reported. The dimensional challenge is met by using a 0.18 μm imaging CMOS process, instead of a conventional CCD process.

First results with prototype ISIS devices for ILC vertex detector

Energy Technology Data Exchange (ETDEWEB)

Damerell, C., E-mail: c.damerell@rl.ac.u [RAL, Oxon OX11 0QX (United Kingdom); Zhang, Z. [RAL, Oxon OX11 0QX (United Kingdom); Gao, R.; John John, Jaya; Li, Y.; Nomerotski, A. [Oxford U (United Kingdom); Holland, A.; Seabroke, G. [Centre for Electronic Imaging, Open U (United Kingdom); Havranek, M. [Czech Technical University in Prague (Czech Republic); Stefanov, K. [Sentec Ltd, Cambridge (United Kingdom); Kar-Roy, A. [Jazz Semiconductors, California (United States); Bell, R.; Burt, D.; Pool, P. [e2V Technologies, Chelmsford (United Kingdom)

2010-12-11

The vertex detectors at the International Linear Collider (ILC) (there will be two of them, one for each of two general purpose detectors) will certainly be built with silicon pixel detectors, either monolithic or perhaps vertically integrated. However, beyond this general statement, there is a wide range of options supported by active R and D programmes all over the world. Pixel-based vertex detectors build on the experience at the SLAC large detector (SLD) operating at the SLAC linear collider (SLC), where a 307 Mpixel detector permitted the highest physics performance at LEP or SLC. For ILC, machine conditions demand much faster readout than at SLC, something like 20 time slices during the 1 ms bunch train. The approach of the image sensor with in-situ storage (ISIS) is unique in offering this capability while avoiding the undesirable requirement of 'pulsed power'. First results from a prototype device that approaches the pixel size of 20 {mu}m square, needed for physics, are reported. The dimensional challenge is met by using a 0.18 {mu}m imaging CMOS process, instead of a conventional CCD process.

Adaptive ILC with an adaptive iterative learnign gain

International Nuclear Information System (INIS)

Ashraf, S.; Muhammad, E.

2008-01-01

This paper describes the design of an adaptive ILC (Iterative Learning Controller) with an iterative learning gain. The basic idea behind ILC is that the information obtained from one trial can be used to improve the control input for the next trial. This proposed scheme extends the idea further and suggests that the information obtained from one trial could also be used to improve control algorithm parameters (gain matrices). The scheme converges faster than the conventional ILC. This convergence and hence number of iterations has always been an issue with ILC. This scheme because of its simple mathematical structure can easily be implemented with lower memory and simpler hardware as opposed to other such adaptive schemes which are computationally expensive. (author)

CXCR6 Expression Is Important for Retention and Circulation of ILC Precursors

Directory of Open Access Journals (Sweden)

Sylvestre Chea

2015-01-01

Full Text Available Innate lymphoid cells are present at mucosal sites and represent the first immune barrier against infections, but what contributes to their circulation and homing is still unclear. Using Rag2−/−Cxcr6Gfp/+ reporter mice, we assessed the expression and role of CXCR6 in the circulation of ILC precursors and their progeny. We identify CXCR6 expressing ILC precursors in the bone marrow and characterize their significant increase in CXCR6-deficient mice at steady state, indicating their partial retention in the bone marrow after CXCR6 ablation. Circulation was also impaired during embryonic life as fetal liver from CXCR6-deficient embryos displayed decreased numbers of ILC3 precursors. When injected, fetal CXCR6-deficient ILC3 precursors also fail to home and reconstitute ILC compartments in vivo. We show that adult intestinal ILC subsets have heterogeneous expression pattern of CXCR6, integrin α4β7, CD62L, CD69, and CD44, with ILC1 and ILC3 being more likely tissue resident lymphocytes. Intestinal ILC subsets were unchanged in percentages and numbers in both mice. We demonstrate that the ILC frequency is maintained due to a significant increase of ILC peripheral proliferation, as well as an increased proliferation of the in situ ILC precursors to compensate their retention in the bone marrow.

Optoelectronic integrated circuits utilising vertical-cavity surface-emitting semiconductor lasers

International Nuclear Information System (INIS)

Zakharov, S D; Fyodorov, V B; Tsvetkov, V V

1999-01-01

Optoelectronic integrated circuits with additional optical inputs/outputs, in which vertical-cavity surface-emitting (VCSE) lasers perform the data transfer functions, are considered. The mutual relationship and the 'affinity' between optical means for data transfer and processing, on the one hand, and the traditional electronic component base, on the other, are demonstrated in the case of implementation of three-dimensional interconnects with a high transmission capacity. Attention is drawn to the problems encountered when semiconductor injection lasers are used in communication lines. It is shown what role can be played by VCSE lasers in solving these problems. A detailed analysis is made of the topics relating to possible structural and technological solutions in the fabrication of single lasers and of their arrays, and also of the problems hindering integrating of lasers into emitter arrays. Considerable attention is given to integrated circuits with optoelectronic smart pixels. Various technological methods for vertical integration of GaAs VCSE lasers with the silicon substrate of a microcircuit (chip) are discussed. (review)

Numerical study of three-dimensional natural convection and entropy generation in a cubical cavity with partially active vertical walls

Directory of Open Access Journals (Sweden)

Abdullah A.A.A Al-Rashed

2017-09-01

Full Text Available Natural convection and entropy generation due to the heat transfer and fluid friction irreversibilities in a three-dimensional cubical cavity with partially heated and cooled vertical walls has been investigated numerically using the finite volume method. Four different arrangements of partially active vertical sidewalls of the cubical cavity are considered. Numerical calculations are carried out for Rayleigh numbers from (103 ≤ Ra ≤ 106, various locations of the partial heating and cooling vertical sidewalls, while the Prandtl number of air is considered constant as Pr=0.7 and the irreversibility coefficient is taken as (φ=10−4. The results explain that the total entropy generation rate increases when the Rayleigh number increases. While, the Bejan number decreases as the Rayleigh number increases. Also, it is found that the arrangements of heating and cooling regions have a significant effect on the fluid flow and heat transfer characteristics of natural convection and entropy generation in a cubical cavity. The Middle-Middle arrangement produces higher values of average Nusselt numbers.

Challenges of the ILC Main Linac

International Nuclear Information System (INIS)

Ross, Marc

2007-01-01

With the completion of the ILC Reference Design Report (RDR), we begin the next phase of the project - development of the Engineering Design. Our strategy and priorities come from the identification, contained in the RDR, of scientific and engineering challenges of the ILC. First among these is the cost of the main linac which, including the associated earthworks and cooling/power systems, amounts to 60% of the ILC total cost. Next is the challenge to reach the highest practical gradient since this R and D has the largest cost leverage of any of the ongoing programs. Finally, we have to understand the beam dynamics and beam tuning processes in the main linac, as we will not have the opportunity to do full (or even large) scale tests of these before the linac is constructed.

Wakefield calculation for superconducting TM110 cavity without azimuthal symmetry

Energy Technology Data Exchange (ETDEWEB)

Bellantoni, Leo; /Fermilab; Burt, Graeme; /Lancaster U.

2006-08-01

The 3.9GHz TM{sub 110} mode deflecting cavity developed at FNAL has many applications, including use as a longitudinal bunch profile diagnostic, and as a crab cavity candidate for the ILC. These applications involve beams with substantial time structure. For the 13-cell version intended for the bunch profile application, long-range wakes have been evaluated in the frequency domain and short-range wakes have been evaluated in the time domain. Higher-order interactions of the main field in the cavity with the beam have also been parameterized. Pedagogic derivations are included as appendices.

Status of SCRF cavity and ADS development in Japan

International Nuclear Information System (INIS)

Yamamoto, Akira

2011-01-01

SCRF cavity technology has progressed with high-energy particle accelerator programs in Japan. It was first applied for TRISTAN program at KEK, in early 1980s, and it is expected to be a key technology to realize the next energy-frontier lepton collider such as ILC, and/or intensity-frontier proton accelerators hopefully to be realized in Japan. The JPARC project as a joint program between JAEA and KEK is scoping to realize ADS program with the linac upgrade using a superconducting cavity system, as a future program. The talk will cover an overview of the SCRF cavity development and the ADS development in Japan. (author)

Numerical study of the thermal and aerodynamic insulation of a cavity with a vertical downstream air jet

Energy Technology Data Exchange (ETDEWEB)

Mhiri, H.; El Golli, S. [Ecole Nationale d`Ingenieurs, Monastir (Tunisia). Lab. d`Energetique; Berthon, A.; Le Palec, G.; Bournot, P. [Technopole de Chateau-Gombert, Marseille (France)

1998-10-01

Because of its numerous industrial applications (air conditioning, thermal insulation, behavior of fires), heat transfer in rectangular cavities has made the subject of many works which concern both theoretical numerical studies and experimental investigations. This work is devoted to a numerical approach of the laminar mixed convection in a cavity which one of the boundaries is materialized by a laminar vertical downstream air jet. The purpose is to analyze the interaction of this flow with the natural movement that grows in the cavity under the combined action of boundary thermal gradients and external medium of the cavity in order to examine thermal insulation qualities of the jet. Calculations have been made with the help of the finite volume method.

Steady-state characteristics of lateral p-n junction vertical-cavity surface-emitting lasers

Science.gov (United States)

Ryzhii, V.; Tsutsui, N.; Khmyrova, I.; Ikegami, T.; Vaccaro, P. O.; Taniyama, H.; Aida, T.

2001-09-01

We developed an analytical device model for lateral p-n junction vertical-cavity surface-emitting lasers (LJVCSELs) with a quantum well active region. The model takes into account the features of the carrier injection, transport, and recombination in LJVCSELs as well as the features of the photon propagation in the cavity. This model is used for the calculation and analysis of the LJVCSEL steady-state characteristics. It is shown that the localization of the injected electrons primarily near the p-n junction and the reabsorption of lateral propagating photons significantly effects the LJVCSELs performance, in particular, the LJVCSEL threshold current and power-current characteristics. The reincarnation of electrons and holes due to the reabsorption of lateral propagating photons can substantially decrease the threshold current.

Novel automatic phase lock determination for superconducting cavity tests at vertical test stand at RRCAT

International Nuclear Information System (INIS)

Singh, Kunver Adarsh Pratap; Mohania, Praveen; Rajput, Vikas; Baxy, Deodatta; Shrivastava, Purushottam

2015-01-01

RRCAT has developed a Vertical Test Stand (VTS) which is used to test the Nb superconducting cavities under cryogenic conditions. In the VTS, RF cavity is characterized for its quality factor variation vs the accelerating gradient. The RF system is an essential part of the VTS which is required to provide stable RF power to the cavity in terms of amplitude, frequency and phase. RF system of VTS consists of several modules including the LLRF system. The LLRF system consists of the 'Frequency Control Module' which controls the input frequency to the SCRF cavity. Due to high quality factor, bandwidth of the cavity is less than 1 Hz. Even slight mechanical vibrations (microphonics) causes change in cavity resonance frequency resulting in total reflection of incident power. A PLL based frequency tracking module has been used to track the resonant frequency of RF cavity. This module changes RF source frequency according to change in Cavity resonance frequency. A novel method using a LabView based computer program has been developed which changes the phase of input RF signal using IQ modulator and monitors the transmitted power, incident and reflected power. The program plots the graph between phase and ratio of transmitted power to incident/reflected power and gives optimum locking phase for operation which has resulted in significant saving in the overall process time for the tests of the cavities in VTS. (author)

Low index contrast heterostructure photonic crystal cavities with high quality factors and vertical radiation coupling

Science.gov (United States)

Ge, Xiaochen; Minkov, Momchil; Fan, Shanhui; Li, Xiuling; Zhou, Weidong

2018-04-01

We report here design and experimental demonstration of heterostructure photonic crystal cavities resonating near the Γ point with simultaneous strong lateral confinement and highly directional vertical radiation patterns. The lateral confinement is provided by a mode gap originating from a gradual modulation of the hole radii. High quality factor resonance is realized with a low index contrast between silicon nitride and quartz. The near surface-normal directional emission is preserved when the size of the core region is scaled down. The influence of the cavity size parameters on the resonant modes is also investigated theoretically and experimentally.

Stress evaluation at the ILC positron source

Energy Technology Data Exchange (ETDEWEB)

Ushakov, Andriy; Moortgat-Pick, Gudrid [Universitaet Hamburg, II. Institut fuer Theoretische Physik, Luruper Chaussee 149, 22761 Hamburg (Germany); Riemann, Sabine; Dietrich, Felix [Deutsches Elektronen-Synchrotron (DESY), Standort Zeuthen, Platanenallee 6, 15738 Zeuthen (Germany); Aulenbacher, Kurt; Tyukin, Valery; Heil, Philipp [Johannes Gutenberg-Universitaet Mainz, Institut fuer Kernphysik, Johann-Joachim-Becher-Weg 45, 55128 Mainz (Germany)

2016-07-01

High luminosity is required at future Linear Colliders which is particularly challenging for all corresponding positron sources. At the International Linear Collider (ILC), polarized positrons are obtained from electron-positron pairs by converting high-energy photons produced by passing the high-energy main electron beam through a helical undulator. The conversion target undergoes cyclic stress with high peak values. To distribute the thermal load, the target is designed as wheel spinning in vacuum with 100 m/s. However, the cyclic stress over long time at high target temperatures could exceed the fatigue stress limit. In the talk, an overview of the ILC positron source is given. The prospects to study material parameters under conditions as expected at the ILC are discussed.

Innate Lymphoid Cells (ILCs): Cytokine Hubs Regulating Immunity and Tissue Homeostasis

NARCIS (Netherlands)

Nagasawa, Maho; Spits, Hergen; Ros, Xavier Romero

2017-01-01

Innate lymphoid cells (ILCs) have emerged as an expanding family of effector cells particularly enriched in the mucosal barriers. ILCs are promptly activated by stress signals and multiple epithelial- and myeloid-cell-derived cytokines. In response, ILCs rapidly secrete effector cytokines, which

Detecting metastable staus and gravitinos at the ILC

International Nuclear Information System (INIS)

Martyn, H.U.

2006-06-01

A study of various SUSY scenarios is presented in which the lightest supersymmetric particle is the gravitino G and the next-to-lightest supersymmetric particle is a scalar tau τ with lifetimes ranging from seconds to years. Gravitinos are interesting dark matter candidates which can be produced in decays of heavier sparticles at the International Linear Collider (ILC), but remain undetected in direct searches of astrophysical experiments. We investigate the detection and measurement of metastable staus, which may be copiously produced at the ILC either directly or via cascade decays. A proper choice of the experimental conditions will allow one to stop large samples of τ's in the calorimeters of the ILC detector and to study the subsequent decays τ → τG. Detailed simulations show that the properties of the stau and the gravitino, such as τ mass and lifetime and G mass, can be accurately determined at a future ILC and may provide direct access to the gravitational coupling, respectively Planck scale. (Orig.)

Innate Lymphoid Cells (ILCs) as Mediators of Inflammation, Release of Cytokines and Lytic Molecules.

Science.gov (United States)

Elemam, Noha Mousaad; Hannawi, Suad; Maghazachi, Azzam A

2017-12-10

Innate lymphoid cells (ILCs) are an emerging group of immune cells that provide the first line of defense against various pathogens as well as contributing to tissue repair and inflammation. ILCs have been classically divided into three subgroups based on their cytokine secretion and transcription factor profiles. ILC nomenclature is analogous to that of T helper cells. Group 1 ILCs composed of natural killer (NK) cells as well as IFN-γ secreting ILC1s. ILC2s have the capability to produce T H 2 cytokines while ILC3s and lymphoid tissue inducer (LTis) are subsets of cells that are able to secrete IL-17 and/or IL-22. A recent subset of ILC known as ILC4 was discovered, and the cells of this subset were designated as NK17/NK1 due to their release of IL-17 and IFN-γ. In this review, we sought to explain the subclasses of ILCs and their roles as mediators of lytic enzymes and inflammation.

Resolution of a High Performance Cavity Beam Position Monitor System

International Nuclear Information System (INIS)

Walston, S.; Chung, C.; Fitsos, P.; Gronberg, J.; Ross, M.; Khainovski, O.; Kolomensky, Y.; Loscutoff, P.; Slater, M.; Thomson, M.; Ward, D.; Boogert, S.; Vogel, V.; Meller, R.; Lyapin, A.; Malton, S.; Miller, D.; Frisch, J.; Hinton, S.; May, J.; McCormick, D.; Smith, S.; Smith, T.; White, G.; Orimoto, T.; Hayano, H.; Honda, Y.; Terunuma, N.; Urakawa, J.

2005-01-01

International Linear Collider (ILC) interaction region beam sizes and component position stability requirements will be as small as a few nanometers. It is important to the ILC design effort to demonstrate that these tolerances can be achieved - ideally using beam-based stability measurements. It has been estimated that RF cavity beam position monitors (BPMs) could provide position measurement resolutions of less than one nanometer and could form the basis of the desired beam-based stability measurement. We have developed a high resolution RF cavity BPM system. A triplet of these BPMs has been installed in the extraction line of the KEK Accelerator Test Facility (ATF) for testing with its ultra-low emittance beam. A metrology system for the three BPMs was recently installed. This system employed optical encoders to measure each BPM's position and orientation relative to a zero-coefficient of thermal expansion carbon fiber frame and has demonstrated that the three BPMs behave as a rigid-body to less than 5 nm. To date, we have demonstrated a BPM resolution of less than 20 nm over a dynamic range of +/- 20 microns

Performance in the vertical test of the 832 nine-cell 1.3 GHz cavities for the European X-ray Free Electron Laser

Science.gov (United States)

Reschke, D.; Gubarev, V.; Schaffran, J.; Steder, L.; Walker, N.; Wenskat, M.; Monaco, L.

2017-04-01

The successful production and associated vertical testing of over 800 superconducting 1.3 GHz accelerating cavities for the European X-ray Free Electron Laser (XFEL) represents the culmination of over 20 years of superconducting radio-frequency R&D. The cavity production took place at two industrial vendors under the shared responsibility of INFN Milano-LASA and DESY. Average vertical testing rates at DESY exceeded 10 cavities per week, peaking at up to 15 cavities per week. The cavities sent for cryomodule assembly at Commissariat à l'énergie atomique (CEA) Saclay achieved an average maximum gradient of approximately 33 MV /m , reducing to ˜30 MV /m when the operational specifications on quality factor (Q) and field emission were included (the so-called usable gradient). Only 16% of the cavities required an additional surface retreatment to recover their low performance (usable gradient less than 20 MV /m ). These cavities were predominantly limited by excessive field emission for which a simple high pressure water rinse (HPR) was sufficient. Approximately 16% of the cavities also received an additional HPR, e.g. due to vacuum problems before or during the tests or other reasons, but these were not directly related to gradient performance. The in-depth statistical analyses presented in this report have revealed several features of the series produced cavities.

Innate Lymphoid Cells (ILCs as Mediators of Inflammation, Release of Cytokines and Lytic Molecules

Directory of Open Access Journals (Sweden)

Noha Mousaad Elemam

2017-12-01

Full Text Available Innate lymphoid cells (ILCs are an emerging group of immune cells that provide the first line of defense against various pathogens as well as contributing to tissue repair and inflammation. ILCs have been classically divided into three subgroups based on their cytokine secretion and transcription factor profiles. ILC nomenclature is analogous to that of T helper cells. Group 1 ILCs composed of natural killer (NK cells as well as IFN-γ secreting ILC1s. ILC2s have the capability to produce TH2 cytokines while ILC3s and lymphoid tissue inducer (LTis are subsets of cells that are able to secrete IL-17 and/or IL-22. A recent subset of ILC known as ILC4 was discovered, and the cells of this subset were designated as NK17/NK1 due to their release of IL-17 and IFN-γ. In this review, we sought to explain the subclasses of ILCs and their roles as mediators of lytic enzymes and inflammation.

A high gradient test of a single-cell superconducting radio frequency cavity with a feedback waveguide

Science.gov (United States)

Kostin, Roman; Avrakhov, Pavel; Kanareykin, Alexei; Solyak, Nikolay; Yakovlev, Vyacheslav; Kazakov, Sergey; Wu, Genfa; Khabiboulline, Timergali; Rowe, Allan; Rathke, John

2015-09-01

The most severe problem of the international linear collider (ILC-type) is its high cost, resulting in part from the enormous length of the collider. This length is determined mainly by the achievable accelerating gradient in the RF system of the collider. In current technology, the maximum acceleration gradient in superconducting (SC) structures is determined mainly by the value of the surface RF magnetic field. In order to increase the gradient, a superconducting traveling wave accelerating (STWA) structure is suggested. Utilization of STWA structure with small phase advance per cell for future high energy linear colliders such as ILCs may provide an accelerating gradient 1.2-1.4 times larger [1] than a standing wave structure. However, STWA structure requires a feedback waveguide for power redirecting from the end of the structure back to the front end of accelerating structure. Recent tests of a 1.3 GHz model of a single-cell cavity with waveguide feedback demonstrated an accelerating gradient comparable to the gradient of a single-cell ILC-type cavity from the same manufacturer [2]. In the present paper, high gradient test results are presented.

Full simulation of the beam-related backgrounds at the ILC

Energy Technology Data Exchange (ETDEWEB)

Schuetz, Anne [DESY (Germany); KIT (Germany)

2016-07-01

The ILC has been proposed as the next machine at the energy frontier and a Technical Design Report was presented in 2012. As part of the site-specific studies to prepare the hosting of the ILC in Japan, the final focus region of the ILC had to be adapted. In this contribution, updated results for the beam-related background as well as new results for the backgrounds originating from the beam dump are presented. The beam-related backgrounds are simulated using GuineaPig and are then propagated through the full simulation of the SiD detector. The impact of various modifications in the final-focus region on the detector occupancies are then evaluated. For the neutron background from the beam dump, the FLUKA simulation suite is used, which is well established for dosimetry and shielding studies. With this program, the effect of the neutrons from the ILC beam dumps on the ILC detectors are studied.

Accelerator Physics for ILC and CLIC

CERN Document Server

Zimmermann, F

2010-01-01

This paper summarizes the second part of the “accelerator physics lectures” delivered at the Ambleside Linear Collider School 2009. It discusses more specific linear-collider issues: superconducting and room-temperature linear accelerators, particle sources for electrons and positrons, synchrotron radiation and damping, intensity limits, beam stability, and beam delivery system – including final focus, collimation, and beam-beam effects. It also presents an overview of the International Linear Collider (ILC), a description of the two beam acceleration scheme of the Compact Linear Collider (CLIC), and a comparison of the ILC and CLIC parameters.

Development of Vertical Buffered Electropolishing for Its Post-Treatment Technology on 1.5 GHz Niobium SRF Cavities

International Nuclear Information System (INIS)

Jin Song; Lu Xiang-Yang; Lin Lin; Zhao Kui; Wu, A. T.; Rimmer, R. A.

2011-01-01

We report the latest research development of vertical buffered electropolishing on its post-treatment procedure as well as the effects of several major post-treatment techniques for buffered electropolishing (BEP) processed 1.5 GHz niobium (Nb) superconducting radio frequency (SRF) cavities. With the established post-treatment procedure, an accelerating gradient of 28.4 MV/m is obtained on a single cell cavity of the cebaf shape. This is the best result in the history of BEP development. The cavity is limited by quench with a high quality factor over 1.2 × 10 10 at the quench point. Analyses from optical inspection and temperature-mapping show that the quench should be originated from the pits that were already present on the cavity before this BEP treatment. All of these factors indicate that this procedure will have a great potential to produce better results if cavities without intrinsic performance limiting imperfections are used. (nuclear physics)

Human innate lymphoid cells (ILCs) in filarial infections.

Science.gov (United States)

Bonne-Année, S; Nutman, T B

2018-02-01

Filarial infections are characteristically chronic and can cause debilitating diseases governed by parasite-induced innate and adaptive immune responses. Filarial parasites traverse or establish niches in the skin (migrating infective larvae), in nonmucosal tissues (adult parasite niche) and in the blood or skin (circulating microfilariae) where they intersect with the host immune response. While several studies have demonstrated that filarial parasites and their antigens can modulate myeloid cells (monocyte, macrophage and dendritic cell subsets), T- and B-lymphocytes and skin resident cell populations, the role of innate lymphoid cells during filarial infections has only recently emerged. Despite the identification and characterization of innate lymphoid cells (ILCs) in murine helminth infections, little is actually known about the role of human ILCs during parasitic infections. The focus of this review will be to highlight the composition of ILCs in the skin, lymphatics and blood; where the host-parasite interaction is well-defined and to examine the role of ILCs during filarial infections. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

Characteristics of innate lymphoid cells (ILCs) and their role in immunological disorders (an update).

Science.gov (United States)

Yazdani, Reza; Sharifi, Mehri; Shirvan, Aylar Saba; Azizi, Gholamreza; Ganjalikhani-Hakemi, Mazdak

2015-01-01

Innate lymphoid cells (ILCs) are a novel family of hematopoietic effectors and regulators of innate immunity. Although these cells are morphologically similar to B cells and T cells, however they do not express antigen receptors. ILCs seems to have emerging roles in innate immune responses against infectious or non-infectious microorganisms, protection of the epithelial barrier, lymphoid organogenesis and inflammation, tissue remodeling and regulating homeostasis of tissue stromal cells. In addition, it has recently been reported that ILCs have a crucial role in several disorders such as allergy and autoimmunity. Based on their phenotype and functions, ILCs are classified into three major groups called ILCs1, ILCs2, and ILCs3. Here we reviewed the most recent data concerning diverse ILC phenotypes, subclasses, functions in immune responses as well as in immune mediated disorders. Copyright © 2015 Elsevier Inc. All rights reserved.

Group 3 innate lymphoid cells (ILC3s): Origin, differentiation, and plasticity in humans and mice.

Science.gov (United States)

Montaldo, Elisa; Juelke, Kerstin; Romagnani, Chiara

2015-08-01

Since their discovery, innate lymphoid cells (ILCs) have been the subject of intense research. As their name implies, ILCs are innate cells of lymphoid origin, and can be grouped into subsets based on their cytotoxic activity, cytokine profile, and the transcriptional requirements during ILC differentiation. The main ILC groups are "killer" ILCs, comprising NK cells, and "helper-like" ILCs (including ILC1s, ILC2s, and ILC3s). This review examines the origin, differentiation stages, and plasticity of murine and human ILC3s. ILC3s express the retinoic acid receptor (RAR) related orphan receptor RORγt and the signature cytokines IL-22 and IL-17. Fetal ILC3s or lymphoid tissue inducer cells are required for lymphoid organogenesis, while postnatally developing ILC3s are important for the generation of intestinal cryptopatches and isolated lymphoid follicles as well as for the defence against pathogens and epithelial homeostasis. Here, we discuss the transcription factors and exogenous signals (including cytokines, nutrients and cell-to-cell interaction) that drive ILC3 lineage commitment and acquisition of their distinctive effector program. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Cryogenics for a vertical test stand facility for testing superconducting radio frequency cavities at RRCAT

International Nuclear Information System (INIS)

Gupta, Prabhat Kumar; Kumar, Manoj; Kush, P.K.

2015-01-01

Vertical Test Stand (VTS) Facility is located in a newly constructed building of Cryo-Engineering and Cryo-Module Development Division (CCDD). This test facility is one of the important facilities to develop SCRF technologies for superconducting accelerators like Indian Spallation Neutron Source. VTS has to be used for regular testing of the Superconducting Radio Frequency (SRF) Niobium cavities at nominal frequency of 1.3 GHz/ 650 MHz at 4 K / 2 K liquid helium (LHe) bath temperatures. Testing of these cavities at 2 K evaluates cavity processing methods, procedures and would also serve as a pre-qualification test for cavity to test it in horizontal cryostat, called horizontal test stand, with other cavity components such as tuner and helium vessel. Cryogenic technologies play a major role in these cavity testing facilities. Achieving and maintaining a stable temperature of 2 K in these test stands on regular and reliable basis is a challenging task and require broad range of cryogenic expertise, large scale system level understanding and many in-house technological and process developments. Furthermore this test stand will handle large amount of liquid helium. Therefore, an appropriately designed infrastructure is required to handle such large amount of helium gas generated during the operation of VTS .This paper describes the different cryogenic design aspects, initial cryogenic operation results and different cryogenic safety aspects. (author)

Development of a TE011 Cavity for Thin-Films Study

CERN Document Server

Martinet, G; Fouaidy, M; Hammoudi, N

2010-01-01

Bulk niobium cavities have almost reached their maximum performances. Maximum accelerating gradient field is above 35-40 MV/m for a multi-cells cavity at 1.8 Kelvin and it achieves 25-30 MV/m with high reliability. The question of increasing the accelerating gradient in a significant way is running regarding the huge amount of units required for new projects (16000 units for ILC). A promising solution is to use thin films of new materials deposited on copper or niobium. In order to investigate the behaviour of these materials for the accelerating cavities, we have developed a dedicated setup based on thermometric method and a TE011 cavity. We present here the design study of the setup and the expected sensitivity of the method for the surface measurement of materials properties under RF fields.

A teststand for photo detectors and beamtests for ILC polarimetry; Aufbau eines Teststandes fuer Photodetektoren und Teststrahlmessungen fuer die Strahlpolarisationsmessung am ILC

Energy Technology Data Exchange (ETDEWEB)

Velte, Ulrich

2009-02-15

In the future International Linear Collider (ILC) up to 80% polarized electrons shall be brought to collision with up to 60% polarized positrons. Because the cross sections of the resulting reactions depend sensitively on the beam polarization this must be measured with a hitherto never reached accuracy of {delta}P/P{approx}0.25%. This shall be reached via Compton scattering of laser photons from the beam particles and subsequent detection of the scattered electrons in a Cherenkov hodoscope. Content of this thesis was to build a teststand, in which different photodetectors for the detection of the Cherenkov light can be characterized and checked on their suitability for the special application in the ILC polarimeter. The until now best polarization measurement was reached in the framework of the SLD experiment at SLAC in California ({delta}P/P{approx}0.5%). At present the Cherenkov counter of the SLD polarimeter is at DESY and is their used in order to measure different photodetectors coming into question for the ILC polarimetry in the test beam. In order to be able to continue the experiences from the SLD experiment in the framework of this thesis test-beam measurements at the Cherenkov detector are evaluated and the first developments towards a polarimeter for the ILC described. [German] Im zukuenftigen International Linear Collider (ILC) sollen bis zu 80% polarisierte Elektronen mit bis zu 60% polarisierten Positronen zur Kollision gebracht werden. Da die Wirkungsquerschnitte der resultierenden Reaktionen empfindlich von der Strahlpolarisation abhaengen, muss diese mit einer bisher nie erreichten Genauigkeit von {delta}P/P{approx}0.25% gemessen werden. Dies soll ueber Compton-Streuung von Laserphotonen an den Strahlteilchen und anschliessendem Nachweis der gestreuten Elektronen in einem Cerenkov-Hodoskop erreicht werden. Inhalt dieser Arbeit war es, einen Teststand aufzubauen, in dem verschiedenartige Photodetektoren zum Nachweis des Cerenkov

Performance in the vertical test of the 832 nine-cell 1.3 GHz cavities for the European X-ray Free Electron Laser

Directory of Open Access Journals (Sweden)

D. Reschke

2017-04-01

Full Text Available The successful production and associated vertical testing of over 800 superconducting 1.3 GHz accelerating cavities for the European X-ray Free Electron Laser (XFEL represents the culmination of over 20 years of superconducting radio-frequency R&D. The cavity production took place at two industrial vendors under the shared responsibility of INFN Milano–LASA and DESY. Average vertical testing rates at DESY exceeded 10 cavities per week, peaking at up to 15 cavities per week. The cavities sent for cryomodule assembly at Commissariat à l’énergie atomique (CEA Saclay achieved an average maximum gradient of approximately 33  MV/m, reducing to ∼30  MV/m when the operational specifications on quality factor (Q and field emission were included (the so-called usable gradient. Only 16% of the cavities required an additional surface retreatment to recover their low performance (usable gradient less than 20  MV/m. These cavities were predominantly limited by excessive field emission for which a simple high pressure water rinse (HPR was sufficient. Approximately 16% of the cavities also received an additional HPR, e.g. due to vacuum problems before or during the tests or other reasons, but these were not directly related to gradient performance. The in-depth statistical analyses presented in this report have revealed several features of the series produced cavities.

Physics highlights at ILC and CLIC

CERN Document Server

Lukić, Strahinja

2015-01-01

In this lecture, the physics potential for the e+e- linear collider experiments ILC and CLIC is reviewed. The experimental conditions are compared to those at hadron colliders and their intrinsic value for precision experiments, complementary to the hadron colliders, is discussed. The detector concepts for ILC and CLIC are outlined in their most important aspects related to the precision physics. Highlights from the physics program and from the benchmark studies are given. It is shown that linear colliders are a promising tool, complementing the LHC in essential ways to test the Standard Model and to search for new physics.

Design and development of RF system for vertical test stand for characterization of superconducting RF cavities

International Nuclear Information System (INIS)

Mohania, Praveen; Rajput, Vikas; Baxy, Deodatta; Agrawal, Ankur; Mahawar, Ashish; Adarsh, Kunver; Singh, Pratap; Shrivastava, Purushottam

2011-01-01

RRCAT is developing a Vertical Test Stand (VTS) to test and qualify 1.3 GHz/650 MHz, SCRF Cavities in collaboration with Fermi National Accelerator Laboratory (FNAL) under Indian Institutions' Fermilab Collaboration. The technical details for VTS is being provided by FNAL, USA. The RF System of VTS needs to provide stable RF power to SCRF cavity with control of amplitude, relative phase and frequency. The incident, reflected, transmitted power and field decay time constant of the cavity are measured to evaluate cavity performance parameters (E, Qo). RF Power is supplied via 500 W Solid State amplifier, 1270-1310 MHz being developed by PHPMS, RRCAT. VTS system is controlled by PXI Platform and National Instruments LabVIEW software. Low Level RF (LLRF) system is used to track the cavity frequency using Phase Locked Loop (PLL). The system is comprised of several integrated functional modules which would be assembled, optimized, and tested separately. Required components and instruments have been identified and procurement for the same is underway. Inhouse development for the Solid State RF amplifier and instrument interfacing is in progress. This paper describes the progress on the development of the RF system for VTS. (author)

Readout ASIC for ILC-FPCCD vertex detector

International Nuclear Information System (INIS)

Takubo, Yosuke; Miyamoto, Akiya; Ikeda, Hirokazu; Yamamoto, Hitoshi; Itagaki, Kennosuke; Nagamine, Tadashi; Sugimoto, Yasuhiro

2010-01-01

The concept of FPCCD (Fine Pixel CCD) whose pixel size is 5x5μm 2 has been proposed as vertex detector at ILC. Since FPCCD has 128 x20,000 pixels in one readout channel, its readout poses a considerable challenge. We have developed a prototype of readout ASIC to readout the large number of pixels during the inter-train gap of the ILC beam. In this paper, we report the design and performance of the readout ASIC.

Recent Developments in SRF Cavity Science and Performance

Energy Technology Data Exchange (ETDEWEB)

G. Ciovati

2006-08-10

The performances of SRF cavities made of high purity bulk niobium have been improving in the last few years and surface magnetic fields (Bp) close to the thermodynamic critical field of niobium have been achieved in a few cases. The recommendation made in 2004 in favor of SRF as the technology of choice for the International Linear Collider (ILC), requires improving the reliability of multi-cell cavities operating at accelerating gradients (Eacc) of the order of 35 MV/m. Additionally, a better understanding of the present limitations to cavity performance, such as the high-field Q-drop is needed. This contribution presents some recent developments in SRF cavity science and performance. Among the most significant advances of the last few years, new cavity shapes with lower ratio Bp/Eacc were designed and tested. Cavities made of large-grain niobium became available, promising lower cost at comparable performance to standard fine-grain ones and several tests on single-cell cavities were done to gain a better understanding of high-field losses. In addition, studies to improve the reliability of electropolishing are being carried out by several research groups.

Evaluation of different photodetector types for an ILC polarimeter

International Nuclear Information System (INIS)

Helebrant, Christian

2009-01-01

At the International Linear Collider (ILC) (ILC Reference Design Report, 2007 ) the polarization of the electron and positron beams needs to be measured with as yet unequaled precision of ΔP/P∼0.25%. The key element of the polarimeter will be the precise detection of Cherenkov light from Compton scattered electrons. The poster ) deals with the choice of a suitable photodetector (PD). In a recently assembled test facility various types of PDs have been checked. Results are presented with a special focus on the linearity of the device, since this is expected to be the limiting factor on the precision of the polarization measurement at the ILC.

Discovering bottom squark coannihilation at the ILC

International Nuclear Information System (INIS)

Belyaev, Alexander; Lastovicka, Tomas; Nomerotski, Andrei; Lastovicka-Medin, Gordana

2010-01-01

We study the potential of the international linear collider (ILC) at √(s)=500 GeV to probe new dark matter motivated scenario where the bottom squark (sbottom) is the next-to-lightest supersymmetric particle. For this scenario, which is virtually impossible for the LHC to test, the ILC has a potential to cover a large fraction of the parameter space. The challenge is due to a very low energy of jets, below 20-30 GeV, which pushes the jet clustering and flavor tagging algorithms to their limits. The process of sbottom pair production was studied within the SiD detector concept. We demonstrate that ILC offers a unique opportunity to test the supersymmetry parameter space motivated by the sbottom-neutralino coannihilation scenario in cases when the sbottom production is kinematically accessible. The study was done with the full SiD simulation and reconstruction chain including all standard model and beam backgrounds.

R&D for the Post-EP Processes of Superconducting RF Cavity

Energy Technology Data Exchange (ETDEWEB)

Saeki, Takayuki [KEK; Funahashi, Y. [KEK; Hayano, H. [KEK; Kato, Seigo [KEK; Nishiwaki, Michiru [KEK; Sawabe, Motoaki [KEK; Ueno, Kenji [KEK; Watanabe, K. [KEK; Antoine, Claire [CEA, Gif-sur-Yvette; Berry, Stefurn [CEA, Gif-sur-Yvette; Eozenou, F. [CEA, Gif-sur-Yvette; Gasser, Y. [CEA, Gif-sur-Yvette; Visentin, B. [CEA, Gif-sur-Yvette; Clemens, William A. [JLAB; Geng, Rongli [JLAB; Manus, Robert [JLAB; Tyagi, Puneet [GUAS/AS, Ibaraki

2009-11-01

The Electro-Polishing (EP) process is the best candidate of final surface treatment for the production of ILC cavities. Nevertheless, the broad distribution of the gradient caused by field emitters in cavities is sitll a serious problem for the EP process. A candidate source of field emitter is the sulfur component which is produced in the EP process and remains the inner-surface of cavities. We studied the effect of Ethanole- and degreaser-rinse processes after the EP process by a unique method. Moreover, we tried to test the sponge cleaning as the post-EP process to remove the field emitter inside the cavcity. This article describe the results of series tests of the post-EP process at KEK.

Conceptual design of an L-band recirculating superconducting traveling wave accelerating structure for ILC

International Nuclear Information System (INIS)

Avrakhov, P.; Kanareykin, A.; Liu, Z.; Kazakov, S.; KEK, Tsukuba; Solyak, N.; Yakovlev, V.; Gai, W.

2007-01-01

With this paper, we propose the conceptual design of a traveling wave accelerating structure for a superconducting accelerator. The overall goal is to study a traveling wave (TW) superconducting (SC) accelerating structure for ILC that allows an increased accelerating gradient and, therefore reduction of the length of the collider. The conceptual studies were performed in order to optimize the acceleration structure design by minimizing the surface fields inside the cavity of the structure, to make the design compatible with existing technology, and to determine the maximum achievable gain in the accelerating gradient. The proposed solution considers RF feedback system redirecting the accelerating wave that passed through the superconducting traveling wave acceleration (STWA) section back to the input of the accelerating structure. The STWA structure has more cells per unit length than a TESLA structure but provides an accelerating gradient higher than a TESLA structure, consequently reducing the cost. In this paper, the STWA cell shape optimization, coupler cell design and feedback waveguide solution are considered. We also discuss the field flatness in the superconducting TW structure, the HOM modes and multipactor performance have been studied as well. The proposed TW structure design gives an overall 46% gain over the SW ILC structure if the 10 m long TW structure is employed

Non-simplified SUSY. τ-coannihilation at LHC and ILC

Energy Technology Data Exchange (ETDEWEB)

Berggren, M.; Kruecker, D.; List, J.; Melzer-Pellmann, I.A.; Seitz, C. [DESY, Hamburg (Germany); Cakir, A. [DESY, Hamburg (Germany); Istanbul Technical University, Department of Physics Engineering, Istanbul (Turkey); Samani, B.S. [DESY, Hamburg (Germany); IPM, P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of); Wayand, S. [KIT IEKP, Karlsruhe (Germany)

2016-04-15

If new phenomena beyond the Standard Model will be discovered at the LHC, the properties of the new particles could be determined with data from the High-Luminosity LHC and from a future linear collider like the ILC. We discuss the possible interplay between measurements at the two accelerators in a concrete example, namely a full SUSY model which features a small τ-LSP mass difference. Various channels have been studied using the Snowmass 2013 combined LHC detector implementation in the Delphes simulation package, as well as simulations of the ILD detector concept from the Technical Design Report. We investigate both the LHC and the ILC capabilities for discovery, separation and identification of various parts of the spectrum. While some parts would be discovered at the LHC, there is substantial room for further discoveries at the ILC. We finally highlight examples where the precise knowledge about the lower part of the mass spectrum which could be acquired at the ILC would enable a more in-depth analysis of the LHC data with respect to the heavier states. (orig.)

Self-mixing interferometry in vertical-cavity surface-emitting lasers for nanomechanical cantilever sensing

DEFF Research Database (Denmark)

Larsson, David; Greve, Anders; Hvam, Jørn Märcher

2009-01-01

We have experimentally investigated self-mixing interference produced by the feedback of light from a polymer micrometer-sized cantilever into a vertical-cavity surface-emitting laser for sensing applications. In particular we have investigated how the visibility of the optical output power...... and the junction voltage depends on the laser injection current and the distance to the cantilever. The highest power visibility obtained from cantilevers without reflective coatings was 60%, resulting in a very high sensitivity of 45 mV/nm with a noise floor below 1.2 mV. Different detection schemes are discussed....

A large superconducting accelerator project. International linear collider (ILC). Introduction

International Nuclear Information System (INIS)

Yamamoto, Akira

2013-01-01

The international linear collider (ILC) is proposed as the next-energy-frontier particle accelerator anticipated to be realized through global cooperation. The ILC accelerator is composed of a pair of electron and positron linear accelerators to realize head-on collision with a center-of-mass energy of 500 (250+250) GeV. It is based on superconducting radio-frequency (SCRF) technology, and the R and D and technical design have progressed in the technical design phase since 2007, and the technical design report (TDR) reached completion in 2012. This report reviews the ILC general design and technology. (author)

Novel Cavities in Vertical External Cavity Surface Emitting Lasers for Emission in Broad Spectral Region by Means of Nonlinear Frequency Conversion

Science.gov (United States)

Lukowski, Michal L.

Optically pumped semiconductor vertical external cavity surface emitting lasers (VECSEL) were first demonstrated in the mid 1990's. Due to the unique design properties of extended cavity lasers VECSELs have been able to provide tunable, high-output powers while maintaining excellent beam quality. These features offer a wide range of possible applications in areas such as medicine, spectroscopy, defense, imaging, communications and entertainment. Nowadays, newly developed VECSELs, cover the spectral regions from red (600 nm) to around 5 microm. By taking the advantage of the open cavity design, the emission can be further expanded to UV or THz regions by the means of intracavity nonlinear frequency generation. The objective of this dissertation is to investigate and extend the capabilities of high-power VECSELs by utilizing novel nonlinear conversion techniques. Optically pumped VECSELs based on GaAs semiconductor heterostructures have been demonstrated to provide exceptionally high output powers covering the 900 to 1200 nm spectral region with diffraction limited beam quality. The free space cavity design allows for access to the high intracavity circulating powers where high efficiency nonlinear frequency conversions and wavelength tuning can be obtained. As an introduction, this dissertation consists of a brief history of the development of VECSELs as well as wafer design, chip fabrication and resonator cavity design for optimal frequency conversion. Specifically, the different types of laser cavities such as: linear cavity, V-shaped cavity and patented T-shaped cavity are described, since their optimization is crucial for transverse mode quality, stability, tunability and efficient frequency conversion. All types of nonlinear conversions such as second harmonic, sum frequency and difference frequency generation are discussed in extensive detail. The theoretical simulation and the development of the high-power, tunable blue and green VECSEL by the means of type I

GaN-based vertical-cavity laser performance improvements using tunnel-junction-cascaded active regions

International Nuclear Information System (INIS)

Piprek, Joachim

2014-01-01

This Letter investigates the output power enhancement achieved by tunnel junction insertion into the InGaN multi-quantum well (MQW) active region of a 410 nm vertical-cavity surface-emitting laser which enables the repeated use of carriers for light generation (carrier recycling). While the number of quantum wells remains unchanged, the tunnel junction eliminates absorption caused by the non-uniform MQW carrier distribution. The thermal resistance drops and the excess bias lead to a surprisingly small rise in self-heating.

Injection and Extraction Lines for the ILC Damping Rings

International Nuclear Information System (INIS)

Reichel, Ina

2007-01-01

The current design for the injection and extraction lines into and out of the ILC Damping Rings is presented as well as the design for the abort line. Due to changes of the geometric boundary conditions by other subsystems of the ILC, a modular approach has been used to be able to respond to recurring layout changes while reusing previously designed parts

Radiation Requirements and Testing of Cryogenic Thermometers for the Ilc

Science.gov (United States)

Barnett, T.; Filippov, Yu. P.; Filippova, E. Yu.; Mokhov, N. V.; Nakao, N.; Klebaner, A. L.; Korenev, S. A.; Theilacker, J. C.; Trenikhina, J.; Vaziri, K.

2008-03-01

Large quantity of cryogenic temperature sensors will be used for operation of the International Linear Collider (ILC). Most of them will be subject to high radiation doses during the accelerator lifetime. Understanding of particle energy spectra, accumulated radiation dose in thermometers and its impact on performance are vital in establishing technical specification of cryogenic thermometry for the ILC. Realistic MARS15 computer simulations were performed to understand the ILC radiation environment. Simulation results were used to establish radiation dose requirements for commercially available cryogenic thermometers. Two types of thermometers, Cernox® and TVO, were calibrated prior to irradiation using different technique. The sensors were subjected then to up to 200 kGy electron beam irradiation with kinetic energy of 5 MeV, a representative of the situation at the ILC operation. A post-irradiation behavior of the sensors was studied. The paper describes the MARS15 model, simulation results, cryogenic test set-up, irradiation tests, and cryogenic test results.

Radiation requirements and testing of cryogenic thermometers for the ILC

International Nuclear Information System (INIS)

Barnett, T.; Filippov, Yu.P.; Mokhov, N.V.; Nakao, N.; Klebaner, A.L.; Korenev, S.A.; Theilacker, J.C.; Trenikhina, J.; Vaziri, K.

2007-01-01

Large quantity of cryogenic temperature sensors will be used for operation of the International Linear Collider (ILC). Most of them will be subject to high radiation doses during the accelerator lifetime. Understanding of particle energy spectra, accumulated radiation dose in thermometers and its impact on performance are vital in establishing technical specification of cryogenic thermometry for the ILC. Realistic MARS15 computer simulations were performed to understand the ILC radiation environment. Simulation results were used to establish radiation dose requirements for commercially available cryogenic thermometers. Two types of thermometers, Cernox(reg s ign) and TVO, were calibrated prior to irradiation using different technique. The sensors were subjected then to up to 200 kGy electron beam irradiation with kinetic energy of 5 MeV, a representative of the situation at the ILC operation. A post-irradiation behavior of the sensors was studied. The paper describes the MARS15 model, simulation results, cryogenic test set-up, irradiation tests, and cryogenic test results

Freeway Traffic Density and On-Ramp Queue Control via ILC Approach

Directory of Open Access Journals (Sweden)

Ronghu Chi

2014-01-01

Full Text Available A new queue length information fused iterative learning control approach (QLIF-ILC is presented for freeway traffic ramp metering to achieve a better performance by utilizing the error information of the on-ramp queue length. The QLIF-ILC consists of two parts, where the iterative feedforward part updates the control input signal by learning from the past control data in previous trials, and the current feedback part utilizes the tracking error of the current learning iteration to stabilize the controlled plant. These two parts are combined in a complementary manner to enhance the robustness of the proposed QLIF-ILC. A systematic approach is developed to analyze the convergence and robustness of the proposed learning scheme. The simulation results are further given to demonstrate the effectiveness of the proposed QLIF-ILC.

Common ground in ILC and CLIC detector concepts

CERN Multimedia

Daisy Yuhas

2013-01-01

The Compact Linear Collider and the International Linear Collider will accelerate particles and create collisions in different ways. Nonetheless, the detector concepts under development share many commonalities.   Timepix chips under scrutiny in the DESY test beam with the help of the beam telescope. CERN physicist Dominik Dannheim explains that the CLIC detector plans are adaptations of the ILC detector designs with a few select modifications. “When we started several years ago, we did not want to reinvent the wheel,” says Dannheim. “The approved ILC detector concepts served as an excellent starting point for our designs.” Essential differences Both CLIC and ILC scientists foresee general-purpose detectors that make measurements with exquisite precision. These colliders, however, have very different operating parameters, which will have important consequences for the various detector components. The ILC’s collision energy is set at 500 GeV ...

VCSELs Fundamentals, Technology and Applications of Vertical-Cavity Surface-Emitting Lasers

CERN Document Server

2013-01-01

The huge progress which has been achieved in the field is covered here, in the first comprehensive monograph on vertical-cavity surface-emitting lasers (VCSELs) since eight years. Apart from chapters reviewing the research field and the laser fundamentals, there are comprehensive updates on red and blue emitting VCSELs, telecommunication VCSELs, optical transceivers, and parallel-optical links for computer interconnects. Entirely new contributions are made to the fields of vectorial three-dimensional optical modeling, single-mode VCSELs, polarization control, polarization dynamics, very-high-speed design, high-power emission, use of high-contrast gratings, GaInNAsSb long-wavelength VCSELs, optical video links, VCSELs for optical mice and sensing, as well as VCSEL-based laser printing. The book appeals to researchers, optical engineers and graduate students.

Post LHC7 SUSY benchmark points for ILC physics

Energy Technology Data Exchange (ETDEWEB)

Baer, Howard [Oklahoma Univ., Norman, OK (United States); List, Jenny [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

2012-05-15

We re-evaluate prospects for supersymmetry at the proposed International Linear e{sup +}e{sup -} Collider (ILC) in light of the first year of serious data taking at LHC with {radical}(s)=7 TeV and {proportional_to}5 fb{sup -1} of pp collisions (LHC7). Strong new limits from LHC SUSY searches, along with a hint of a Higgs boson signal around m{sub h}{proportional_to}125 GeV, suggest a paradigm shift from previously popular models to ones with new and compelling signatures. We present a variety of new ILC benchmark models, including: natural SUSY, hidden SUSY, NUHM2 with low m{sub A}, non-universal gaugino mass (NUGM) model, pMSSM, Kallosh-Linde model, Bruemmer-Buchmueller model, normal scalar mass hierarchy (NMH) plus one surviving case from mSUGRA/CMSSM in the far focus point region. While all these models at present elude the latest LHC limits, they do offer intriguing case study possibilities for ILC operating at {radical}(s){proportional_to}0.25-1 TeV, and present a view of some of the diverse SUSY phenomena which might be expected at both LHC and ILC in the post LHC7 era.

Post LHC7 SUSY benchmark points for ILC physics

International Nuclear Information System (INIS)

Baer, Howard; List, Jenny

2012-05-01

We re-evaluate prospects for supersymmetry at the proposed International Linear e + e - Collider (ILC) in light of the first year of serious data taking at LHC with √(s)=7 TeV and ∝5 fb -1 of pp collisions (LHC7). Strong new limits from LHC SUSY searches, along with a hint of a Higgs boson signal around m h ∝125 GeV, suggest a paradigm shift from previously popular models to ones with new and compelling signatures. We present a variety of new ILC benchmark models, including: natural SUSY, hidden SUSY, NUHM2 with low m A , non-universal gaugino mass (NUGM) model, pMSSM, Kallosh-Linde model, Bruemmer-Buchmueller model, normal scalar mass hierarchy (NMH) plus one surviving case from mSUGRA/CMSSM in the far focus point region. While all these models at present elude the latest LHC limits, they do offer intriguing case study possibilities for ILC operating at √(s)∝0.25-1 TeV, and present a view of some of the diverse SUSY phenomena which might be expected at both LHC and ILC in the post LHC7 era.

Automated optical inspection and image analysis of superconducting radio-frequency cavities

Energy Technology Data Exchange (ETDEWEB)

Wenskat, Marc

2017-04-15

The inner surface of superconducting cavities plays a crucial role to achieve highest accelerating fields and low losses. For an investigation of this inner surface of more than 100 cavities within the cavity fabrication for the European XFEL and the ILC HiGrade Research Project, an optical inspection robot OBACHT was constructed. To analyze up to 2325 images per cavity, an image processing and analysis code was developed and new variables to describe the cavity surface were obtained. The accuracy of this code is up to 97% and the PPV 99% within the resolution of 15.63 μm. The optical obtained surface roughness is in agreement with standard profilometric methods. The image analysis algorithm identified and quantified vendor specific fabrication properties as the electron beam welding speed and the different surface roughness due to the different chemical treatments. In addition, a correlation of ρ=-0.93 with a significance of 6σ between an obtained surface variable and the maximal accelerating field was found.

Automated optical inspection and image analysis of superconducting radio-frequency cavities

International Nuclear Information System (INIS)

Wenskat, Marc

2017-04-01

The inner surface of superconducting cavities plays a crucial role to achieve highest accelerating fields and low losses. For an investigation of this inner surface of more than 100 cavities within the cavity fabrication for the European XFEL and the ILC HiGrade Research Project, an optical inspection robot OBACHT was constructed. To analyze up to 2325 images per cavity, an image processing and analysis code was developed and new variables to describe the cavity surface were obtained. The accuracy of this code is up to 97% and the PPV 99% within the resolution of 15.63 μm. The optical obtained surface roughness is in agreement with standard profilometric methods. The image analysis algorithm identified and quantified vendor specific fabrication properties as the electron beam welding speed and the different surface roughness due to the different chemical treatments. In addition, a correlation of ρ=-0.93 with a significance of 6σ between an obtained surface variable and the maximal accelerating field was found.

Effort towards symmetric removal and surface smoothening of 1.3-GHz niobium single-cell cavity in vertical electropolishing using a unique cathode

Science.gov (United States)

Chouhan, Vijay; Kato, Shigeki; Nii, Keisuke; Yamaguchi, Takanori; Sawabe, Motoaki; Hayano, Hitoshi; Ida, Yoshiaki

2017-08-01

A detailed study on vertical electropolishing (VEP) of a 1.3-GHz single-cell niobium coupon cavity, which contains six coupons and four viewports at different positions, is reported. The cavity was vertically electropolished using a conventional rod and three types of unique cathodes named as Ninja cathodes, which were designed to have four retractable blades made of either an insulator or a metal or a combination of both. This study reveals the effect of the cathodes and their rotation speed on uniformity in removal thickness and surface morphology at different positions inside the cavity. Removal thickness was measured at several positions of the cavity using an ultrasonic thickness gauge and the surface features of the coupons were examined by an optical microscope and a surface profiler. The Ninja cathode with partial metallic blades was found to be effective not only in reducing asymmetric removal, which is one of the major problems in VEP and might be caused by the accumulation of hydrogen (H2 ) gas bubbles on the top iris of the cavity, but also in yielding a smooth surface of the entire cavity. A higher rotation speed of the Ninja cathode prevents bubble accumulation on the upper iris, and might result in a viscous layer of similar thickness in the cavity cell. Moreover, a higher electric field at the equator owing to the proximity of partial metallic blades to the equator surface resulted in a smooth surface. The effects of H2 gas bubbles and stirring were also observed in lab EP experiments.

Effort towards symmetric removal and surface smoothening of 1.3-GHz niobium single-cell cavity in vertical electropolishing using a unique cathode

Directory of Open Access Journals (Sweden)

Vijay Chouhan

2017-08-01

Full Text Available A detailed study on vertical electropolishing (VEP of a 1.3-GHz single-cell niobium coupon cavity, which contains six coupons and four viewports at different positions, is reported. The cavity was vertically electropolished using a conventional rod and three types of unique cathodes named as Ninja cathodes, which were designed to have four retractable blades made of either an insulator or a metal or a combination of both. This study reveals the effect of the cathodes and their rotation speed on uniformity in removal thickness and surface morphology at different positions inside the cavity. Removal thickness was measured at several positions of the cavity using an ultrasonic thickness gauge and the surface features of the coupons were examined by an optical microscope and a surface profiler. The Ninja cathode with partial metallic blades was found to be effective not only in reducing asymmetric removal, which is one of the major problems in VEP and might be caused by the accumulation of hydrogen (H_{2} gas bubbles on the top iris of the cavity, but also in yielding a smooth surface of the entire cavity. A higher rotation speed of the Ninja cathode prevents bubble accumulation on the upper iris, and might result in a viscous layer of similar thickness in the cavity cell. Moreover, a higher electric field at the equator owing to the proximity of partial metallic blades to the equator surface resulted in a smooth surface. The effects of H_{2} gas bubbles and stirring were also observed in lab EP experiments.

Self-mixing interferometry in vertical-cavity surface-emitting lasers for nanomechanical cantilever sensing

Science.gov (United States)

Larsson, David; Greve, Anders; Hvam, Jørn M.; Boisen, Anja; Yvind, Kresten

2009-03-01

We have experimentally investigated self-mixing interference produced by the feedback of light from a polymer micrometer-sized cantilever into a vertical-cavity surface-emitting laser for sensing applications. In particular we have investigated how the visibility of the optical output power and the junction voltage depends on the laser injection current and the distance to the cantilever. The highest power visibility obtained from cantilevers without reflective coatings was ˜60%, resulting in a very high sensitivity of 45 mV/nm with a noise floor below 1.2 mV. Different detection schemes are discussed.

CLIC/ILC Researchers Explore New Avenues for Collaboration

CERN Multimedia

Katarina Anthony

2010-01-01

Researchers from CLIC and ILC met for their first common International Workshop on Linear Colliders, which was held in Geneva from 18 to 22 October. Although the talks were mostly scientific and technical, the political message behind them was a breakthrough, as the workshop showed the progress made in unifying the two communities.   The International Workshop on Linear Colliders (IWLC), which was organised by the European Committee for Future Accelerators, hosted by CERN, and held at CERN and the International Conference Centre in Geneva, attracted a large audience of about 500 experts. Although there have been other joint conferences between the CLIC and ILC communities before, they have all been focused on specific technical and/or managerial issues. The IWLC was part of an ongoing effort by CLIC and ILC to provide an environment in which researchers can exchange ideas, inform their peers about their most recent achievements and work together on common issues. Given the possible technical ov...

Nonpolar III-nitride vertical-cavity surface-emitting lasers incorporating an ion implanted aperture

KAUST Repository

Leonard, J. T.; Cohen, D. A.; Yonkee, B. P.; Farrell, R. M.; Margalith, T.; Lee, S.; DenBaars, S. P.; Speck, J. S.; Nakamura, S.

2015-01-01

© 2015 AIP Publishing LLC. We report on our recent progress in improving the performance of nonpolar III-nitride vertical-cavity surface-emitting lasers (VCSELs) by using an Al ion implanted aperture and employing a multi-layer electron-beam evaporated ITO intracavity contact. The use of an ion implanted aperture improves the lateral confinement over SiNx apertures by enabling a planar ITO design, while the multi-layer ITO contact minimizes scattering losses due to its epitaxially smooth morphology. The reported VCSEL has 10 QWs, with a 3nm quantum well width, 1nm barriers, a 5nm electron-blocking layer, and a 6.95- λ total cavity thickness. These advances yield a single longitudinal mode 406nm nonpolar VCSEL with a low threshold current density (∼16kA/cm²), a peak output power of ∼12μW, and a 100% polarization ratio. The lasing in the current aperture is observed to be spatially non-uniform, which is likely a result of filamentation caused by non-uniform current spreading, lateral optical confinement, contact resistance, and absorption loss.

Nonpolar III-nitride vertical-cavity surface-emitting lasers incorporating an ion implanted aperture

KAUST Repository

Leonard, J. T.

2015-07-06

© 2015 AIP Publishing LLC. We report on our recent progress in improving the performance of nonpolar III-nitride vertical-cavity surface-emitting lasers (VCSELs) by using an Al ion implanted aperture and employing a multi-layer electron-beam evaporated ITO intracavity contact. The use of an ion implanted aperture improves the lateral confinement over SiNx apertures by enabling a planar ITO design, while the multi-layer ITO contact minimizes scattering losses due to its epitaxially smooth morphology. The reported VCSEL has 10 QWs, with a 3nm quantum well width, 1nm barriers, a 5nm electron-blocking layer, and a 6.95- λ total cavity thickness. These advances yield a single longitudinal mode 406nm nonpolar VCSEL with a low threshold current density (∼16kA/cm²), a peak output power of ∼12μW, and a 100% polarization ratio. The lasing in the current aperture is observed to be spatially non-uniform, which is likely a result of filamentation caused by non-uniform current spreading, lateral optical confinement, contact resistance, and absorption loss.

Track reconstruction at the ILC: the ILD tracking software

International Nuclear Information System (INIS)

Gaede, Frank; Aplin, Steven; Rosemann, Christoph; Voutsinas, Georgios; Glattauer, Robin

2014-01-01

One of the key requirements for Higgs physics at the International Linear Collider ILC is excellent track reconstruction with very good momentum and impact parameter resolution. ILD is one of the two detector concepts at the ILC. Its central tracking system comprises of an outer Si-tracker, a highly granular TPC, an intermediate silicon tracker and a pixel vertex detector, and it is complemented by silicon tracking disks in the forward direction. Large hit densities from beam induced coherent electron-positron pairs at the ILC pose an additional challenge to the pattern recognition algorithms. We present the recently developed new ILD tracking software, the pattern recognition algorithms that are using clustering techniques, Cellular Automatons and Kalman filter based track extrapolation. The performance of the ILD tracking system is evaluated using a detailed simulation including dead material, gaps and imperfections.

Development of III-Sb metamorphic DBR membranes on InP for vertical cavity laser applications

Science.gov (United States)

Addamane, S. J.; Mansoori, A.; Renteria, E. J.; Dawson, N.; Shima, D. M.; Rotter, T. J.; Hains, C. P.; Dawson, L. R.; Balakrishnan, G.

2016-04-01

Sb-based metamorphic DBR membranes are developed for InP-based vertical cavity laser applications. The reflectivity of the metamorphic DBR membrane is compared to the reflectivity of a lattice-matched DBR to characterize the optical quality of the DBR membrane. The metamorphic interface between InP and the III-antimonides is found to degrade the reflectivity of the DBR. Therefore, the growth temperature for the metamorphic DBR is optimized in order to obtain highly reflective (>99.8%) III-Sb thin-film membranes.

Production of Seamless Superconducting Radio Frequency Cavities from Ultra-fine Grained Niobium, Phase II Final Report

Energy Technology Data Exchange (ETDEWEB)

Roy Crooks, Ph.D., P.E.

2009-10-31

The positron and electron linacs of the International Linear Collider (ILC) will require over 14,000, nine-cell, one meter length, superconducting radio frequency (SRF) cavities [ILC Reference Design Report, 2007]. Manufacturing on this scale will benefit from more efficient fabrication methods. The current methods of fabricating SRF cavities involve deep drawing of the halves of each of the elliptical cells and joining them by high-vacuum, electron beam welding, with at least 19 circumferential welds per cavity. The welding is costly and has undesirable effects on the cavity surfaces, including grain-scale surface roughening at the weld seams. Hydroforming of seamless tubes avoids welding, but hydroforming of coarse-grained seamless tubes results in strain-induced surface roughening. Surface roughness limits accelerating fields, because asperities prematurely exceed the critical magnetic field and become normal conducting. This project explored the technical and economic feasibility of an improved processing method for seamless tubes for hydroforming. Severe deformation of bulk material was first used to produce a fine structure, followed by extrusion and flow-forming methods of tube making. Extrusion of the randomly oriented, fine-grained bulk material proceeded under largely steady-state conditions, and resulted in a uniform structure, which was found to be finer and more crystallographically random than standard (high purity) RRR niobium sheet metal. A 165 mm diameter billet of RRR grade niobium was processed into five, 150 mm I.D. tubes, each over 1.8 m in length, to meet the dimensions used by the DESY ILC hydroforming machine. Mechanical properties met specifications. Costs of prototype tube production were approximately twice the price of RRR niobium sheet, and are expected to be comparable with economies of scale. Hydroforming and superconducting testing will be pursued in subsequent collaborations with DESY and Fermilab. SRF Cavities are used to construct

Down-regulation of E protein activity augments an ILC2 differentiation program in the thymus

Science.gov (United States)

Innate lymphoid cells (ILCs) are important regulators in various immune responses. Current paradigm states that all newly-made ILCs originate from common lymphoid progenitors (CLP) in the bone marrow. Id2, an inhibitor of E protein transcription factors, is indispensable for ILC differentiation. Une...

Performance test of a vertically-directed electric-field cavity resonator made for the rapid gelation apparatus with microwave heating

International Nuclear Information System (INIS)

Yamagishi, Shigeru; Ogawa, Toru; Hasegawa, Atsushi.

1996-06-01

A cavity resonator with vertically-directed electric field was produced and attached to 'the rapid gelation apparatus with microwave heating' previously reported. Using the rapid gelation apparatus, drops of a simulated solution and of U-containing solutions for internal gelation were heated. The results indicated that the heating required for gelation of the U-containing solutions was possible. However, the electric field strength in the cavity resonator at that time was comparable to that causing the discharge due to the gaseous ammonia released from the heated drops. As a result, gel microspheres were not obtained in a stable state. The discussion suggests that the stable gelation would be realized by improving the cavity resonator shape and/or by modifying the power supply accompanied with using a power stabilizer. (author)

Development of optical inspection system of L-band SRF cavity

International Nuclear Information System (INIS)

Tajima, Yujiro; Iwashita, Yoshihisa; Hayano, Hitoshi

2008-01-01

The International Linear Collider (ILC) will require about 15,000 1.3 GHz superconducting radio frequency (SRF) accelerating cavities with high accelerating gradient (>35 MV/m) in its main linac. The high yield (80%) of successful high gradient cavities is necessary. Both of the yield and the accelerating gradient of SRF cavities does not reach the required level at present. We think that the gradient of the SRF cavities is limited by irregularities on the interior surface of the cavities, for example, fine dusts (1μm), balls (100μm) and pits (100μm): electrons emitted from the fine dusts by the tunnel effect are accelerated in the electric field, and consume the stored energy of the cavities (Field Emission). The balls and pits cause a breakdown by a magnetic field enhancement or a thermal current concentration (Thermal Breakdown). To prevent these problems the interior surface are treated by polishing and rinsing. The relation between the surface states and the gradient limitations, however, is still not clarified. To study the relation, we are developing an optical inspection system of the interior surface. (author)

Hidden particle production at the ILC

International Nuclear Information System (INIS)

Fujii, Keisuke; Itoh, Hideo; Okada, Nobuchika; Hano, Hitoshi; Yoshioka, Tamaki

2008-01-01

In a class of new physics models, the new physics sector is completely or partly hidden, namely, a singlet under the standard model (SM) gauge group. Hidden fields included in such new physics models communicate with the standard model sector through higher-dimensional operators. If a cutoff lies in the TeV range, such hidden fields can be produced at future colliders. We consider a scalar field as an example of the hidden fields. Collider phenomenology on this hidden scalar is similar to that of the SM Higgs boson, but there are several features quite different from those of the Higgs boson. We investigate productions of the hidden scalar at the International Linear Collider (ILC) and study the feasibility of its measurements, in particular, how well the ILC distinguishes the scalar from the Higgs boson, through realistic Monte Carlo simulations.

A metrology system for a high resolution cavity beam position monitor system

Science.gov (United States)

Walston, Sean; Boogert, Stewart; Chung, Carl; Fitsos, Pete; Frisch, Joe; Gronberg, Jeff; Hayano, Hitoshi; Hinton, Shantell; Honda, Yosuke; Khainovski, Oleg; Kolomensky, Yury; Loscutoff, Peter; Lyapin, Alexey; Malton, Stephen; May, Justin; McCormick, Douglas; Meller, Robert; Miller, David; Orimoto, Toyoko; Ross, Marc; Slater, Mark; Smith, Steve; Smith, Tonee; Terunuma, Nobuhiro; Thomson, Mark; Urakawa, Junji; Vogel, Vladimir; Ward, David; White, Glen

2013-11-01

International Linear Collider (ILC) interaction region beam sizes and component position stability requirements will likely be as small as a few nanometers. It is important to the ILC design effort to demonstrate that these tolerances can be achieved-ideally using a beam-based stability measurement. We developed a high resolution RF cavity Beam Position Monitor (BPM) system. A triplet of these BPMs, installed in the extraction line of the KEK Accelerator Test Facility (ATF) and tested with its ultra-low emittance beam, achieved a position measurement resolution of 15 nm. A metrology system for the three BPMs was subsequently installed. This system employed optical encoders to measure each BPM's position and orientation relative to a zero-coefficient of thermal expansion carbon fiber frame. We have demonstrated that the three BPMs behave as a rigid-body at the level of less than 5 nm.

Automated optical inspection and image analysis of superconducting radio-frequency cavities

Science.gov (United States)

Wenskat, M.

2017-05-01

The inner surface of superconducting cavities plays a crucial role to achieve highest accelerating fields and low losses. For an investigation of this inner surface of more than 100 cavities within the cavity fabrication for the European XFEL and the ILC HiGrade Research Project, an optical inspection robot OBACHT was constructed. To analyze up to 2325 images per cavity, an image processing and analysis code was developed and new variables to describe the cavity surface were obtained. The accuracy of this code is up to 97 % and the positive predictive value (PPV) 99 % within the resolution of 15.63 μm. The optical obtained surface roughness is in agreement with standard profilometric methods. The image analysis algorithm identified and quantified vendor specific fabrication properties as the electron beam welding speed and the different surface roughness due to the different chemical treatments. In addition, a correlation of ρ = -0.93 with a significance of 6 σ between an obtained surface variable and the maximal accelerating field was found.

Cryomodule tests of the TESLA-like superconducting cavity in KEK-STF

International Nuclear Information System (INIS)

Kako, Eiji; Sato, Masato; Shishido, Toshio; Noguchi, Shuichi; Hatori, Hirofumi; Hayano, Hitoshi; Yamamoto, Yasuchika; Watanabe, Ken

2008-01-01

Construction of STF (Superconducting RF Test Facility) is being carried out at KEK. The STF-Baseline superconducting cavity system, which includes four TESLA-like 9-cell cavities, input couplers and frequency tuners, has been developed for the future ILC project. A 6-m cryomodule including one of four TESLA-like cavities was assembled, and the cryomodule was installed in the tunnel for the initial test, called the STF Phase-0.5. The first cool-down of the cryomodule and high power tests of the cavity had been carried out at 2 K from October to November, 2007. The maximum accelerating gradient (Eacc, max) of 19.3 MV/m was achieved in a specific pulse width of 1.5 msec and a repetition rate of 5 Hz, (23.4 MV/m in a shorter pulse width of 0.6 msec). Compensation of Lorentz force detuning at 18 MV/m was successfully demonstrated by using a piezo tuner. The second cryomodule test for four cavities, called the STF Phase-1.0, is scheduled in July, 2008. (author)

ILC in 2012: Decisions ahead!

CERN Multimedia

Barry Barish, Director of the Global Design Effort for the International Linear Collider

2011-01-01

The 2000 or so people from around the world who are planning and developing the International Linear Collider (ILC) are starting to get this funny feeling when something that you have been working on and looking forward to for a long, long time is suddenly just around the corner.   Simulation of a Higgs event in a future ILC detector. Copyright: DESY 2006. 2012 will be a big one for the potential next big thing in particle physics: towards the end of the year the community plans to release its Technical Design Report, that all-important publication that basically says “we’re ready – just say the word”. Of course the future of particle physics in the world depends crucially on results from the LHC, so we are all curious (on the edge of our seats may describe it more appropriately) to see what the big discovery machine will tell us about Standard Model Higgs particles (or not), dark matter and all those other unsolved mysteries on which...

ILC in 2012: Decisions ahead!

CERN Multimedia

Barry Barish, Director of the Global Design Effort for the International Linear Collider

2012-01-01

The 2000 or so people from around the world who are planning and developing the International Linear Collider (ILC) are starting to get this funny feeling when something that you have been working on and looking forward to for a long, long time is suddenly just around the corner.   Simulation of a Higgs event in a future ILC detector. Copyright: DESY 2006. 2012 will be a big one for the potential next big thing in particle physics: towards the end of the year the community plans to release its Technical Design Report, that all-important publication that basically says “we’re ready – just say the word”. Of course the future of particle physics in the world depends crucially on results from the LHC, so we are all curious (on the edge of our seats may describe it more appropriately) to see what the big discovery machine will tell us about Standard Model Higgs particles (or not), dark matter and all those other unsolved mysteries on which...

Analysis of fluid-solid interaction in MHD natural convection in a square cavity equally partitioned by a vertical flexible membrane

International Nuclear Information System (INIS)

Mehryan, S.A.M.; Ghalambaz, Mohammad; Ismael, Muneer A.; Chamkha, Ali J.

2017-01-01

This paper investigates numerically the problem of unsteady natural convection inside a square cavity partitioned by a flexible impermeable membrane. The finite element method with the arbitrary Lagrangian-Eulerian (ALE) technique has been used to model the interaction of the fluid and the membrane. The horizontal walls of the cavity are kept adiabatic while the vertical walls are kept isothermal at different temperatures. A uniform magnetic field is applied onto the cavity with different orientations. The cavity has been provided by two eyelets to compensate volume changes due the movement of the flexible membrane. A parametric study is carried out for the pertinent parameters, which are the Rayleigh number (10"5–10"8), Hartmann number (0–200) and the orientation of the magnetic field (0–180°). The change in the Hartmann number affects the shape of the membrane and the heat transfer in the cavity. The angle of the magnetic field orientation also significantly affects the shape of the membrane and the heat transfer in the cavity. - Highlights: • Magnetohydrodynamics heat transfer in a partitioned cavity is studied. • There is a flexible membrane in the cavity. • The membrane is modeled using fluid-solid structure interaction. • A moving grid formulation based on ALE is adopted. • The effect of the magnetic field on the natural convection heat transfer is examined.

Analysis of fluid-solid interaction in MHD natural convection in a square cavity equally partitioned by a vertical flexible membrane

Energy Technology Data Exchange (ETDEWEB)

Mehryan, S.A.M., E-mail: a.mansuri1366@gmail.com [Department of Mechanical Engineering, Dezful Branch, Islamic Azad University, Dezful (Iran, Islamic Republic of); Ghalambaz, Mohammad, E-mail: m.ghalambaz@iaud.ac.ir [Department of Mechanical Engineering, Dezful Branch, Islamic Azad University, Dezful (Iran, Islamic Republic of); Ismael, Muneer A., E-mail: muneerismael@yahoo.com [Mechanical Engineering Department, Engineering College, University of Basrah, Basrah (Iraq); Chamkha, Ali J., E-mail: achamkha@pmu.edu.sa [Mechanical Engineering Department, Prince Mohammad Bin Fahd University, Al-Khobar 31952 (Saudi Arabia); Prince Sultan Endowment for Energy and Environment, Prince Mohammad Bin Fahd University, Al-Khobar 31952 (Saudi Arabia)

2017-02-15

This paper investigates numerically the problem of unsteady natural convection inside a square cavity partitioned by a flexible impermeable membrane. The finite element method with the arbitrary Lagrangian-Eulerian (ALE) technique has been used to model the interaction of the fluid and the membrane. The horizontal walls of the cavity are kept adiabatic while the vertical walls are kept isothermal at different temperatures. A uniform magnetic field is applied onto the cavity with different orientations. The cavity has been provided by two eyelets to compensate volume changes due the movement of the flexible membrane. A parametric study is carried out for the pertinent parameters, which are the Rayleigh number (10{sup 5}–10{sup 8}), Hartmann number (0–200) and the orientation of the magnetic field (0–180°). The change in the Hartmann number affects the shape of the membrane and the heat transfer in the cavity. The angle of the magnetic field orientation also significantly affects the shape of the membrane and the heat transfer in the cavity. - Highlights: • Magnetohydrodynamics heat transfer in a partitioned cavity is studied. • There is a flexible membrane in the cavity. • The membrane is modeled using fluid-solid structure interaction. • A moving grid formulation based on ALE is adopted. • The effect of the magnetic field on the natural convection heat transfer is examined.

Few-mode vertical-cavity surface-emitting laser: Optional emission of transverse modes with different polarizations

Science.gov (United States)

Zhong, Chuyu; Zhang, Xing; Hofmann, Werner; Yu, Lijuan; Liu, Jianguo; Ning, Yongqiang; Wang, Lijun

2018-05-01

Few-mode vertical-cavity surface-emitting lasers that can be controlled to emit certain modes and polarization states simply by changing the biased contacts are proposed and fabricated. By directly etching trenches in the p-doped distributed Bragg reflector, the upper mesa is separated into several submesas above the oxide layer. Individual contacts are then deposited. Each contact is used to control certain transverse modes with different polarization directions emitted from the corresponding submesa. These new devices can be seen as a prototype of compact laser sources in mode division multiplexing communications systems.

Post LHC8 SUSY benchmark points for ILC physics

International Nuclear Information System (INIS)

Baer, Howard; List, Jenny

2013-07-01

We re-evaluate prospects for supersymmetry at the proposed International Linear e + e - Collider (ILC) in light of the first two years of serious data taking at LHC: LHC7 with ∝5 fb -1 of pp collisions at √(s)=7 TeV and LHC8 with ∝20 fb -1 at √(s)=8 TeV. Strong new limits from LHC8 SUSY searches, along with the discovery of a Higgs boson with m h ≅125 GeV, suggest a paradigm shift from previously popular models to ones with new and compelling signatures. After a review of the current status of supersymmetry, we present a variety of new ILC benchmark models, including: natural SUSY, radiatively-driven natural SUSY (RNS), NUHM2 with low m A , a focus point case from mSUGRA/CMSSM, non-universal gaugino mass (NUGM) model, τ-coannihilation, Kallosh-Linde/spread SUSY model, mixed gauge-gravity mediation, normal scalar mass hierarchy (NMH), and one example with the recently discovered Higgs boson being the heavy CP-even state H. While all these models at present elude the latest LHC8 limits, they do offer intriguing case study possibilities for ILC operating at √(s)≅ 0.25-1 TeV. The benchmark points also present a view of the widely diverse SUSY phenomena which might still be expected in the post LHC8 era at both LHC and ILC.

Post LHC8 SUSY benchmark points for ILC physics

Energy Technology Data Exchange (ETDEWEB)

Baer, Howard [Oklahoma Univ., Norman, OK (United States); List, Jenny [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

2013-07-15

We re-evaluate prospects for supersymmetry at the proposed International Linear e{sup +}e{sup -} Collider (ILC) in light of the first two years of serious data taking at LHC: LHC7 with {proportional_to}5 fb{sup -1} of pp collisions at {radical}(s)=7 TeV and LHC8 with {proportional_to}20 fb{sup -1} at {radical}(s)=8 TeV. Strong new limits from LHC8 SUSY searches, along with the discovery of a Higgs boson with m{sub h}{approx_equal}125 GeV, suggest a paradigm shift from previously popular models to ones with new and compelling signatures. After a review of the current status of supersymmetry, we present a variety of new ILC benchmark models, including: natural SUSY, radiatively-driven natural SUSY (RNS), NUHM2 with low m{sub A}, a focus point case from mSUGRA/CMSSM, non-universal gaugino mass (NUGM) model, {tau}-coannihilation, Kallosh-Linde/spread SUSY model, mixed gauge-gravity mediation, normal scalar mass hierarchy (NMH), and one example with the recently discovered Higgs boson being the heavy CP-even state H. While all these models at present elude the latest LHC8 limits, they do offer intriguing case study possibilities for ILC operating at {radical}(s){approx_equal} 0.25-1 TeV. The benchmark points also present a view of the widely diverse SUSY phenomena which might still be expected in the post LHC8 era at both LHC and ILC.

Interim report on the Global Design Effort Global International Linear Collider (ILC) R&D

Energy Technology Data Exchange (ETDEWEB)

Harrison, M.

2011-04-30

The International Linear Collider: A Technical Progress Report marks the halfway point towards the Global Design Effort fulfilling its mandate to follow up the ILC Reference Design Report with a more optimised Technical Design Report (TDR) by the end of 2012. The TDR will be based on much of the work reported here and will contain all the elements needed to propose the ILC to collaborating governments, including a technical design and implementation plan that are realistic and have been better optimised for performance, cost and risk. We are on track to develop detailed plans for the ILC, such that once results from the Large Hadron Collider (LHC) at CERN establish the main science goals and parameters of the next machine, we will be in good position to make a strong proposal for this new major global project in particle physics. The two overriding issues for the ILC R&D programme are to demonstrate that the technical requirements for the accelerator are achievable with practical technologies, and that the ambitious physics goals can be addressed by realistic ILC detectors. This GDE interim report documents the impressive progress on the accelerator technologies that can make the ILC a reality. It highlights results of the technological demonstrations that are giving the community increased confidence that we will be ready to proceed with an ILC project following the TDR. The companion detector and physics report document likewise demonstrates how detector designs can meet the ambitious and detailed physics goals set out by the ILC Steering Committee. LHC results will likely affect the requirements for the machine design and the detectors, and we are monitoring that very closely, intending to adapt our design as those results become available.

A 3D deep n-well CMOS MAPS for the ILC vertex detector

Energy Technology Data Exchange (ETDEWEB)

Gaioni, L., E-mail: luigi.gaioni@unipv.i [Universita di Pavia, I-27100 Pavia (Italy); INFN, Sezione di Pavia, I-27100 Pavia (Italy); Manghisoni, M. [Universita di Bergamo, I-24044 Dalmine (Bulgaria) (Italy); INFN, Sezione di Pavia, I-27100 Pavia (Italy); Ratti, L. [Universita di Pavia, I-27100 Pavia (Italy); INFN, Sezione di Pavia, I-27100 Pavia (Italy); Re, V.; Traversi, G. [Universita di Bergamo, I-24044 Dalmine (Bulgaria) (Italy); INFN, Sezione di Pavia, I-27100 Pavia (Italy)

2010-05-21

This work presents the features of a new kind of deep n-well monolithic active pixel sensor (DNW-MAPS), called SDR1 (Sparsified Data Readout), which exploits the capabilities of vertical integration (3D) processing in view of the design of a high granularity detector for vertexing applications at the International Linear Collider (ILC). SDR1 inherits and extends the functional capabilities of DNW-MAPS fabricated in planar (2D) CMOS technology and is expected to show better collection efficiency with respect to 2D versions. The aim of the paper is to outline the features of analog and digital architecture of the SDR1 chip, together with circuit simulations data. Also some device simulation results concerning detection efficiency will be discussed.

Impact of optical feedback on current-induced polarization behavior of 1550 nm vertical-cavity surface-emitting lasers.

Science.gov (United States)

Deng, Tao; Wu, Zheng-Mao; Xie, Yi-Yuan; Wu, Jia-Gui; Tang, Xi; Fan, Li; Panajotov, Krassimir; Xia, Guang-Qiong

2013-06-01

Polarization switching (PS) between two orthogonal linearly polarized fundamental modes is experimentally observed in commercial free-running 1550 nm vertical-cavity surface-emitting lasers (VCSELs) (Raycan). The characteristics of this PS are strongly modified after introducing a polarization-preserved (PP) or polarization-orthogonal (PO) optical feedback. Under the case that the external cavity is approximately 30 cm, the PP optical feedback results in the PS point shifting toward a lower injection current, and the region within which the two polarization modes coexist is enlarged with the increase of the PP feedback strength. Under too-strong PP feedback levels, the PS disappears. The impact of PO optical feedback on VCSEL polarization behavior is quite similar to that of PP optical feedback, but larger feedback strength is needed to obtain similar results.

Results from the first single cell Nb₃Sn cavity coatings at JLab

Energy Technology Data Exchange (ETDEWEB)

Eremeev, Grigory [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

2015-09-01

Nb₃Sn is a promising superconducting material for SRF applications and has the potential to exceed the limitations of niobium. We have used the recently commissioned Nb₃Sn coating system to investigate Nb₃Sn coatings on several single cell cavities by applying the same coating procedure on several different single cells with different history and pre-coating surface preparation. We report on our findings with four 1.5 GHz CEBAF-shape single cell and one 1.3 GHz ILC-shape single cavities that were coated, inspected, and tested.

WIMP search and a Cherenkov detector prototype for ILC polarimetry

Energy Technology Data Exchange (ETDEWEB)

Bartels, Christoph

2011-10-15

The planned International Linear Collider (ILC) will be an essential experiment to precisely determine the properties and structure of physics at the TeV scale. An important feature of the ILC is the possibility to use polarized electrons and positrons. In part 1 of this thesis, a model independent search for Weakly Interacting Massive Particles (WIMPs) at ILC is presented. The signal channel under study is direct WIMP pair production with associated Initial State Radiation (ISR), e{sup +}e{sup -} {yields} {chi}{chi}{gamma}, where the WIMPs leave the detector without any further interaction, and only the emitted photon is detected. From the energy spectrum of the detected photons the coupling structure, cross sections, masses and the quantum number of the dominant partial wave in the production process can be inferred. The analysis includes the dominant SM, as well as machine-induced backgrounds, and is performed using a full simulation of the ILD detector concept. For an integrated luminosity of L=500 fb{sup -1}, the signal cross sections can be measured to a precision of 3%, dominated by systematic uncertainties on the polarization measurement of the initial electrons and positrons. Masses can be measured to a precision of up to 2% by a comparison of the data photon spectrum to parametrized template spectra. In part 2 of this thesis, a Cherenkov detector prototype for Compton polarimetry at ILC is presented. For the polarization measurement a systematic uncertainty of {delta} P/P = 0.25% or better is envisioned. To achieve this goal, the Cherenkov detector has to be precisely aligned with the fan of Compton scattered electrons and its signal response needs to be highly linear. For the detector prototype data driven alignment strategies have been developed by comparing data recorded at the Elsa accelerator in Bonn, Germany, with detailed Geant4 simulations. With the use of multi-anode photomultipliers, data driven alignment strategies promise to provide the

WIMP search and a Cherenkov detector prototype for ILC polarimetry

International Nuclear Information System (INIS)

Bartels, Christoph

2011-10-01

The planned International Linear Collider (ILC) will be an essential experiment to precisely determine the properties and structure of physics at the TeV scale. An important feature of the ILC is the possibility to use polarized electrons and positrons. In part 1 of this thesis, a model independent search for Weakly Interacting Massive Particles (WIMPs) at ILC is presented. The signal channel under study is direct WIMP pair production with associated Initial State Radiation (ISR), e + e - → χχγ, where the WIMPs leave the detector without any further interaction, and only the emitted photon is detected. From the energy spectrum of the detected photons the coupling structure, cross sections, masses and the quantum number of the dominant partial wave in the production process can be inferred. The analysis includes the dominant SM, as well as machine-induced backgrounds, and is performed using a full simulation of the ILD detector concept. For an integrated luminosity of L=500 fb -1 , the signal cross sections can be measured to a precision of 3%, dominated by systematic uncertainties on the polarization measurement of the initial electrons and positrons. Masses can be measured to a precision of up to 2% by a comparison of the data photon spectrum to parametrized template spectra. In part 2 of this thesis, a Cherenkov detector prototype for Compton polarimetry at ILC is presented. For the polarization measurement a systematic uncertainty of δ P/P = 0.25% or better is envisioned. To achieve this goal, the Cherenkov detector has to be precisely aligned with the fan of Compton scattered electrons and its signal response needs to be highly linear. For the detector prototype data driven alignment strategies have been developed by comparing data recorded at the Elsa accelerator in Bonn, Germany, with detailed Geant4 simulations. With the use of multi-anode photomultipliers, data driven alignment strategies promise to provide the required precision. At ILC, these

Modeling radiation loads in the ILC main linac and a novel approach to treat dark current

Energy Technology Data Exchange (ETDEWEB)

Mokhov, Nilolai V. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Rakhno, Igor L. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Tropin, Igor S. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

2017-09-11

Electromagnetic and hadron showers generated by electrons of dark current (DC) can represent a significant radiation threat to the ILC linac equipment and personnel. In this study, a commissioning scenario is analysed which is considered as the worst-case scenario for the main linac regarding the DC contribution to the radiation environment in the tunnel. A normal operation scenario is analysed as well. An emphasis is made on radiation load to sensitive electronic equipment—cryogenic thermometers inside the cryomodules. Prompt and residual dose rates in the ILC main linac tunnels were also calculated in these new high-statistics runs. A novel approach was developed—as a part of general purpose Monte Carlo code MARS15—to model generation, acceleration and transport of DC electrons in electromagnetic fields inside SRF cavities. Comparisons were made with a standard approach when a set of pre-calculated DC electron trajectories is used, with a proper normalization, as a source for Monte Carlo modelling. Results of MARS15 Monte Carlo calculations, performed for the current main linac tunnel design, reveal that the peak absorbed dose in the cryogenic thermometers in the main tunnel for 20 years of operation is about 0.8 MGy. The calculated contact residual dose on cryomodules and tunnel walls in the main tunnel for typical irradiation and cooling conditions is 0.1 and 0.01 mSv/hr, respectively.

Non-simplified SUSY. {tau}-coannihilation at LHC and ILC

Energy Technology Data Exchange (ETDEWEB)

Berggren, M.; Cakir, A.; Krueger, D.; List, J.; Lobanov, A.; Melzer-Pellmann, I.A.

2013-07-15

Simplified models have become a widely used and important tool to cover the more diverse phenomenology beyond constrained SUSY models. However, they come with a substantial number of caveats themselves, and great care needs to be taken when drawing conclusions from limits based on the simplified approach. To illustrate this issue with a concrete example, we examine the applicability of simplified model results to a series of full SUSY model points which all feature a small {tau} -LSP mass difference, and are compatible with electroweak and flavor precision observables as well as current LHC results. Various channels have been studied using the Snowmass Combined LHC detector implementation in the Delphes simulation package, as well as the Letter of Intent or Technical Design Report simulations of the ILD detector concept at the ILC. We investigated both the LHC and ILC capabilities for discovery, separation and identification of all parts of the spectrum. While parts of the spectrum would be discovered at the LHC, there is substantial room for further discoveries and property determination at the ILC.

Bilinear R parity violation at the ILC. Neutrino physics at colliders

International Nuclear Information System (INIS)

List, J.; Vormwald, B.; Hamburg Univ.

2013-07-01

Supersymmetry (SUSY) with bilinearly broken R parity (bRPV) offers an attractive possibility to explain the origin of neutrino masses and mixings. Thereby neutralinos become a probe to the neutrino sector since studying neutralino decays gives access to neutrino parameters at colliders. We present the study of a bRPV SUSY model at the International Linear Collider (ILC), with the bRPV parameters determined from current neutrino data. The ILC offers a very clean environment to study the neutralino properties as well as their subsequent decays, which typically involve a W/Z and a lepton. This study is based on ILC beam parameters according to the Technical Design Report for a center of mass energy of 500 GeV. Full detector simulation of the International Large Detector (ILD) was performed for SUSY and Standard Model processes. We show for the fully simulated example point that the χ 0 1 mass can be reconstructed with an uncertainty of less than 0.2% for an integrated luminosity of 100 fb -1 from direct χ 0 1 pair production, thus to a large extent independently of the rest of the SUSY spectrum. We also demonstrate that the achievable precision on the atmospheric neutrino mixing angle sin 2 θ 23 from measuring the neutralino branching fractions BR(χ 0 1 →Wμ) and BR(χ 0 1 →Wτ) at the ILC is comparable to current uncertainties from neutrino experiments. Thus the ILC could have the opportunity to unveil the mechanism of neutrino mass generation.

A metrology system for a high resolution cavity beam position monitor system

Energy Technology Data Exchange (ETDEWEB)

Walston, Sean, E-mail: walston2@llnl.gov [Lawrence Livermore National Laboratory, 7000 East Ave., L-181, Livermore, CA 94550 (United States); Boogert, Stewart [Royal Holloway, University of London, Egham (United Kingdom); Chung, Carl; Fitsos, Pete [Lawrence Livermore National Laboratory, 7000 East Ave., L-181, Livermore, CA 94550 (United States); Frisch, Joe [Stanford Linear Accelerator Center, Menlo Park, CA (United States); Gronberg, Jeff [Lawrence Livermore National Laboratory, 7000 East Ave., L-181, Livermore, CA 94550 (United States); Hayano, Hitoshi [High Energy Accelerator Research Organization (KEK), Tsukuba-shi, Ibaraki-ken (Japan); Hinton, Shantell [Stanford Linear Accelerator Center, Menlo Park, CA (United States); Honda, Yosuke [High Energy Accelerator Research Organization (KEK), Tsukuba-shi, Ibaraki-ken (Japan); Khainovski, Oleg; Kolomensky, Yury; Loscutoff, Peter [University of California and Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Lyapin, Alexey; Malton, Stephen [University College London, London (United Kingdom); May, Justin; McCormick, Douglas [Stanford Linear Accelerator Center, Menlo Park, CA (United States); Meller, Robert [Cornell University, Ithaca, NY (United States); Miller, David [University College London, London (United Kingdom); Orimoto, Toyoko [University of California and Lawrence Berkeley National Laboratory, Berkeley, CA (United States); California Institute of Technology, Pasadena, CA (United States); Ross, Marc [Stanford Linear Accelerator Center, Menlo Park, CA (United States); Fermi National Accelerator Laboratory, Batavia, IL (United States); and others

2013-11-11

International Linear Collider (ILC) interaction region beam sizes and component position stability requirements will likely be as small as a few nanometers. It is important to the ILC design effort to demonstrate that these tolerances can be achieved–ideally using a beam-based stability measurement. We developed a high resolution RF cavity Beam Position Monitor (BPM) system. A triplet of these BPMs, installed in the extraction line of the KEK Accelerator Test Facility (ATF) and tested with its ultra-low emittance beam, achieved a position measurement resolution of 15 nm. A metrology system for the three BPMs was subsequently installed. This system employed optical encoders to measure each BPM's position and orientation relative to a zero-coefficient of thermal expansion carbon fiber frame. We have demonstrated that the three BPMs behave as a rigid-body at the level of less than 5 nm.

4.5 μm wavelength vertical external cavity surface emitting laser operating above room temperature

Science.gov (United States)

Rahim, M.; Khiar, A.; Felder, F.; Fill, M.; Zogg, H.

2009-05-01

A midinfrared vertical external cavity surface emitting laser with 4.5 μm emission wavelength and operating above room temperature has been realized. The active part consists of a single 850 nm thick epitaxial PbSe gain layer. It is followed by a 2 1/2 pair Pb1-yEuyTe/BaF2 Bragg mirror. No microstructural processing is needed. Excitation is done optically with a 1.5 μm wavelength laser. The device operates up to 45 °C with 100 ns pulses and delivers 6 mW output power at 27 °C heat-sink temperature.

Present status of superconducting cavity developments

Energy Technology Data Exchange (ETDEWEB)

Ouchi, Nobuo; Kusano, Joichi; Hasegawa, Kazuo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment] [and others

1997-11-01

An R and D work of a superconducting (SC) cavity for the high intensity proton linac has begun at JAERI in collaboration with KEK. The RF field calculation and the structural analysis have been made to determine the cavity shape in the proton energy range between 100 and 1500 MeV. The results indicate the feasibility of a SC proton linac. A vertical test stand with clean room, water rinsing system, cavity evacuation pumping system, cryostat and data acquisition system has been installed to demonstrate the cavity performance. A single cell cavity of {beta}=0.5 has been fabricated and tested at the test stand to obtain the Q-value and the maximum surface electric field strength. The measured Q-values have been found to be high enough for our requirement while the field strength was limited to about 75% of the specification by the multipacting. We describe the preliminary design of the SC cavity, the overview of the vertical test stand and experimental results of the single cell cavity. (author)

An Architecture Proposal for the ILC Test Beam Silicon Telescope at Fermilab

Energy Technology Data Exchange (ETDEWEB)

Turqueti, M.A.; /Fermilab

2007-04-01

The requirements for an ILC Test Beam silicon telescope system are foreseen to be very stringent. Resolution, noise, and throughput must be carefully managed in order to provide a useful instrument for the high energy physics community to develop detector technologies for the ILC. Since the ILC Test Beam is meant to test a wide variety of different detectors, it must employ universally accepted software techniques, hardware standards and protocols as well as easy integration of hardware and software with the various clients using the system. In this paper, we describe an open modular architecture to achieve these goals, including an analysis of the entire chain of software and hardware needed to meet the requirements.

Performance of TESLA Cavities After Fabrication and Preparation in Industry

CERN Document Server

Pekeler, Michael; Bauer, Stefan; Knobloch, Jens; Vom Stein, Peter

2005-01-01

In order to demonstrate cw operation of TESLA cavities in linear accelerators driving FEL applications, two TESLA cavities were manufactured and prepared by ACCEL for BESSY. After production, both cavities were prepared for vertical test at ACCEL's premises using state of the art chemical polishing and high pressure water rinsing techniques. The cavities were tested in DESY's vertical RF test installation. Accelerating gradients close to 25 MV/m were reached. One cavity was completed with a helium vessel modified for cw operation and prepared with chemical polishing, high pressure water rinsing, and assembled with the required High Power Coupler at ACCEL. The fully dressed cavity was then shipped under vacuum to BESSY and tested in the horizontal cryostat HoBiCaT. Horizontal RF test results will be presented and compared with the vertical test results.

Vacuum systems for the ILC helical undulator

CERN Document Server

Malyshev, O B; Clarke, J A; Bailey, I R; Dainton, J B; Malysheva, L I; Barber, D P; Cooke, P; Baynham, E; Bradshaw, T; Brummitt, A; Carr, S; Ivanyushenkov, Y; Rochford, J; Moortgat-Pick, G A

2007-01-01

The International Linear Collider (ILC) positron source uses a helical undulator to generate polarized photons of ∼10MeV∼10MeV at the first harmonic. Unlike many undulators used in synchrotron radiation sources, the ILC helical undulator vacuum chamber will be bombarded by photons, generated by the undulator, with energies mostly below that of the first harmonic. Achieving the vacuum specification of ∼100nTorr∼100nTorr in a narrow chamber of 4–6mm4–6mm inner diameter, with a long length of 100–200m100–200m, makes the design of the vacuum system challenging. This article describes the vacuum specifications and calculations of the flux and energy of photons irradiating the undulator vacuum chamber and considers possible vacuum system design solutions for two cases: cryogenic and room temperature.

Study of a DEPFET vertex detector and of supersymmetric smuons at the ILC

Energy Technology Data Exchange (ETDEWEB)

Chen, Xun

2009-01-21

This thesis is devoted to the study of the performance of a pixel vertex detector based on DEPFET technology at the International Linear Collider (ILC). The ILC is the proposed next generation e{sup +}e{sup -} collider to explore the physics at the Terascale. At the ILC with its well-defined initial state of collisions, possible discoveries at the Large Hadron Collider can be verified and studied more accurately. It is expected that the precision measurements of the ILC will answer many fundamental questions about the universe, such as the generation of particle masses and the origin of electroweak spontaneous symmetry breaking. The ambitious physics goals present challenges to the ILC detectors. Several detector concepts have been proposed in recent years. A crucial device for all these concepts is the pixel vertex detector. It provides precise impact parameter information of charged particles, jet flavor tagging and improves overall tracking efficiency. To meet the requirements of the ILC environment, the vertex detector will be arranged in a concentric multi-layer array around the interaction point to cover as large a solid angle as possible. Endcap disks are considered in some designs. Silicon pixel sensor technologies must be employed to provide excellent point resolution. The DEPFET technology, which integrates the first level of amplification into a depleted silicon bulk, is one of the promising candidates. The DEPFET sensor is very sensitive with a high signal-to-noise ratio. Power consumption is minimized due to the internal storage of signal charges. The good radiation tolerance makes it capable of working close to the interaction point. In this thesis, we discuss the detailed simulation of the DEPFET vertex detector, following the general vertex detector layout proposed by the TESLA collaboration. The simulation is used to evaluate the impact parameter resolution. We also discuss the DEPFET test beam analysis on two-track resolution. The whole analysis

Study of a DEPFET vertex detector and of supersymmetric smuons at the ILC

International Nuclear Information System (INIS)

Chen, Xun

2009-01-01

This thesis is devoted to the study of the performance of a pixel vertex detector based on DEPFET technology at the International Linear Collider (ILC). The ILC is the proposed next generation e + e - collider to explore the physics at the Terascale. At the ILC with its well-defined initial state of collisions, possible discoveries at the Large Hadron Collider can be verified and studied more accurately. It is expected that the precision measurements of the ILC will answer many fundamental questions about the universe, such as the generation of particle masses and the origin of electroweak spontaneous symmetry breaking. The ambitious physics goals present challenges to the ILC detectors. Several detector concepts have been proposed in recent years. A crucial device for all these concepts is the pixel vertex detector. It provides precise impact parameter information of charged particles, jet flavor tagging and improves overall tracking efficiency. To meet the requirements of the ILC environment, the vertex detector will be arranged in a concentric multi-layer array around the interaction point to cover as large a solid angle as possible. Endcap disks are considered in some designs. Silicon pixel sensor technologies must be employed to provide excellent point resolution. The DEPFET technology, which integrates the first level of amplification into a depleted silicon bulk, is one of the promising candidates. The DEPFET sensor is very sensitive with a high signal-to-noise ratio. Power consumption is minimized due to the internal storage of signal charges. The good radiation tolerance makes it capable of working close to the interaction point. In this thesis, we discuss the detailed simulation of the DEPFET vertex detector, following the general vertex detector layout proposed by the TESLA collaboration. The simulation is used to evaluate the impact parameter resolution. We also discuss the DEPFET test beam analysis on two-track resolution. The whole analysis procedures

Particle-in-Cell Calculations of the Electron Cloud in the ILC Positron Damping Ring Wigglers

International Nuclear Information System (INIS)

Celata, C.M.; Furman, M.A.; Vay, J.-L.; Grote, D.P.

2007-01-01

The self-consistent code suite WARP-POSINST is being used to study electron cloud effects in the ILC positron damping ring wiggler. WARP is a parallelized, 3D particle-in-cell code which is fully self-consistent for all species. The POSINST models for the production of photoelectrons and secondary electrons are used to calculate electron creation. Mesh refinement and a moving reference frame for the calculation will be used to reduce the computer time needed by several orders of magnitude. We present preliminary results for cloud buildup showing 3D electron effects at the nulls of the vertical wiggler field. First results from a benchmark of WARP-POSINST vs. POSINST are also discussed

Bilinear R parity violation at the ILC. Neutrino physics at colliders

Energy Technology Data Exchange (ETDEWEB)

List, J. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Vormwald, B. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Hamburg Univ. (Germany). Inst. fuer Experimentalphysik

2013-07-15

Supersymmetry (SUSY) with bilinearly broken R parity (bRPV) offers an attractive possibility to explain the origin of neutrino masses and mixings. Thereby neutralinos become a probe to the neutrino sector since studying neutralino decays gives access to neutrino parameters at colliders. We present the study of a bRPV SUSY model at the International Linear Collider (ILC), with the bRPV parameters determined from current neutrino data. The ILC offers a very clean environment to study the neutralino properties as well as their subsequent decays, which typically involve a W/Z and a lepton. This study is based on ILC beam parameters according to the Technical Design Report for a center of mass energy of 500 GeV. Full detector simulation of the International Large Detector (ILD) was performed for SUSY and Standard Model processes. We show for the fully simulated example point that the {chi}{sup 0}{sub 1} mass can be reconstructed with an uncertainty of less than 0.2% for an integrated luminosity of 100 fb{sup -1} from direct {chi}{sup 0}{sub 1} pair production, thus to a large extent independently of the rest of the SUSY spectrum. We also demonstrate that the achievable precision on the atmospheric neutrino mixing angle sin{sup 2} {theta}{sub 23} from measuring the neutralino branching fractions BR({chi}{sup 0}{sub 1}{yields}W{mu}) and BR({chi}{sup 0}{sub 1}{yields}W{tau}) at the ILC is comparable to current uncertainties from neutrino experiments. Thus the ILC could have the opportunity to unveil the mechanism of neutrino mass generation.

Innovations in ILC detector design using a particle flow algorithm approach

International Nuclear Information System (INIS)

Magill, S.; High Energy Physics

2007-01-01

The International Linear Collider (ILC) is a future e + e - collider that will produce particles with masses up to the design center-of-mass (CM) energy of 500 GeV. The ILC complements the Large Hadron Collider (LHC) which, although colliding protons at 14 TeV in the CM, will be luminosity-limited to particle production with masses up to ∼1-2 TeV. At the ILC, interesting cross-sections are small, but there are no backgrounds from underlying events, so masses should be able to be measured by hadronic decays to dijets (∼80% BR) as well as in leptonic decay modes. The precise measurement of jets will require major detector innovations, in particular to the calorimeter, which will be optimized to reconstruct final state particle 4-vectors--called the particle flow algorithm approach to jet reconstruction

A GaInAsP/InP Vertical Cavity Surface Emitting Laser for 1.5 m m operation

Science.gov (United States)

Sceats, R.; Balkan, N.; Adams, M. J.; Masum, J.; Dann, A. J.; Perrin, S. D.; Reid, I.; Reed, J.; Cannard, P.; Fisher, M. A.; Elton, D. J.; Harlow, M. J.

1999-04-01

We present the results of our studies concerning the pulsed operation of a bulk GaInAsP/InP vertical cavity surface emitting laser (VCSEL). The device is tailored to emit at around 1.5 m m at room temperature. The structure has a 45 period n-doped GaInAsP/InP bottom distributed Bragg reflector (DBR), and a 4 period Si/Al2O3 dielectric top reflector defining a 3-l cavity. Electroluminescence from a 16 m m diameter top window was measured in the pulsed injection mode. Spectral measurements were recorded in the temperature range between 125K and 240K. Polarisation, lasing threshold current and linewidth measurements were also carried out at the same temperatures. The threshold current density has a broad minimum at temperatures between 170K and 190K, (Jth=13.2 kA/cm2), indicating a good match between the gain and the cavity resonance in this temperature range. Maximum emitted power from the VCSEL is 0.18 mW at 180K.

Fast calculation of the `ILC norm' in iterative learning control

Science.gov (United States)

Rice, Justin K.; van Wingerden, Jan-Willem

2013-06-01

In this paper, we discuss and demonstrate a method for the exploitation of matrix structure in computations for iterative learning control (ILC). In Barton, Bristow, and Alleyne [International Journal of Control, 83(2), 1-8 (2010)], a special insight into the structure of the lifted convolution matrices involved in ILC is used along with a modified Lanczos method to achieve very fast computational bounds on the learning convergence, by calculating the 'ILC norm' in ? computational complexity. In this paper, we show how their method is equivalent to a special instance of the sequentially semi-separable (SSS) matrix arithmetic, and thus can be extended to many other computations in ILC, and specialised in some cases to even faster methods. Our SSS-based methodology will be demonstrated on two examples: a linear time-varying example resulting in the same ? complexity as in Barton et al., and a linear time-invariant example where our approach reduces the computational complexity to ?, thus decreasing the computation time, for an example, from the literature by a factor of almost 100. This improvement is achieved by transforming the norm computation via a linear matrix inequality into a check of positive definiteness - which allows us to further exploit the almost-Toeplitz properties of the matrix, and additionally provides explicit upper and lower bounds on the norm of the matrix, instead of the indirect Ritz estimate. These methods are now implemented in a MATLAB toolbox, freely available on the Internet.

Optical surface properties and their RF limitations of European XFEL cavities

Energy Technology Data Exchange (ETDEWEB)

Wenskat, Marc

2017-04-15

The inner surface of superconducting cavities plays a crucial role to achieve highest accelerating fields and low losses. The industrial fabrication of cavities for the European X-Ray Free Electron Laser (XFEL) and the International Linear Collider (ILC) HiGrade Research Project allowed for an investigation of this interplay. For the serial inspection of the inner surface, the optical inspection robot OBACHT was constructed and to analyze the large amount of data, represented in the images of the inner surface, an image processing and analysis code was developed and new variables to describe the cavity surface were obtained. This quantitative analysis identified vendor specific surface properties which allow to perform a quality control and assurance during the production. In addition, a strong negative correlation of ρ=-0.93 with a significance of 6σ of the integrated grain boundary area ΣA versus the maximal achievable accelerating field E{sub acc,max} has been found.

Optical surface properties and their RF limitations of European XFEL cavities

International Nuclear Information System (INIS)

Wenskat, Marc

2017-04-01

The inner surface of superconducting cavities plays a crucial role to achieve highest accelerating fields and low losses. The industrial fabrication of cavities for the European X-Ray Free Electron Laser (XFEL) and the International Linear Collider (ILC) HiGrade Research Project allowed for an investigation of this interplay. For the serial inspection of the inner surface, the optical inspection robot OBACHT was constructed and to analyze the large amount of data, represented in the images of the inner surface, an image processing and analysis code was developed and new variables to describe the cavity surface were obtained. This quantitative analysis identified vendor specific surface properties which allow to perform a quality control and assurance during the production. In addition, a strong negative correlation of ρ=-0.93 with a significance of 6σ of the integrated grain boundary area ΣA versus the maximal achievable accelerating field E acc,max has been found.

Natural convection with evaporation in a vertical cylindrical cavity under the effect of temperature-dependent surface tension

Science.gov (United States)

Kozhevnikov, Danil A.; Sheremet, Mikhail A.

2018-01-01

The effect of surface tension on laminar natural convection in a vertical cylindrical cavity filled with a weak evaporating liquid has been analyzed numerically. The cylindrical enclosure is insulated at the bottom, heated by a constant heat flux from the side, and cooled by a non-uniform evaporative heat flux from the top free surface having temperature-dependent surface tension. Governing equations with corresponding boundary conditions formulated in dimensionless stream function, vorticity, and temperature have been solved by finite difference method of the second-order accuracy. The influence of Rayleigh number, Marangoni number, and aspect ratio on the liquid flow and heat transfer has been studied. Obtained results have revealed that the heat transfer rate at free surface decreases with Marangoni number and increases with Rayleigh number, while the average temperature inside the cavity has an opposite behavior; namely, it growths with Marangoni number and reduces with Rayleigh number.

AHR prevents human IL-1R1hi ILC3 differentiation to natural killer cells

Science.gov (United States)

Hughes, Tiffany; Briercheck, Edward L.; Freud, Aharon G.; Trotta, Rossana; McClory, Susan; Scoville, Steven D.; Keller, Karen; Deng, Youcai; Cole, Jordan; Harrison, Nicholas; Mao, Charlene; Zhang, Jianying; Benson, Don M.; Yu, Jianhua; Caligiuri, Michael A.

2014-01-01

SUMMARY Accumulating evidence indicates that human natural killer (NK) cells develop in secondary lymphoid tissue (SLT) through a so-called “stage 3” developmental intermediate minimally characterized by a CD34-CD117+CD94- immunophenotype that lacks mature NK cell function. This stage 3 population is heterogeneous, potentially composed of functionally distinct innate lymphoid cell (ILC) types that includes interleukin-1 receptor (IL-1R1) positive, IL-22-producing ILC3s. Whether human ILC3s are developmentally related to NK cells is a subject of ongoing investigation. Here we show that antagonism of the aryl hydrocarbon receptor (AHR) or silencing of AHR gene expression promotes differentiation of tonsillar IL-22-producing IL-1R1hi human ILC3s to CD56brightCD94+ IFN-gamma-producing cytolytic mature NK cells expressing eomesodermin (EOMES) and T-Box Protein 21 (TBX21 or TBET). Hence, AHR is a transcription factor that prevents human IL-1R1hi ILC3s from differentiating into NK cells. PMID:24953655

Characterization of innate lymphoid cells in human skin and blood demonstrates increase of NKp44+ ILC3 in psoriasis.

Science.gov (United States)

Villanova, Federica; Flutter, Barry; Tosi, Isabella; Grys, Katarzyna; Sreeneebus, Hemawtee; Perera, Gayathri K; Chapman, Anna; Smith, Catherine H; Di Meglio, Paola; Nestle, Frank O

2014-04-01

Innate lymphoid cells (ILCs) are increasingly appreciated as key regulators of tissue immunity. However, their role in human tissue homeostasis and disease remains to be fully elucidated. Here we characterize the ILCs in human skin from healthy individuals and from the inflammatory skin disease psoriasis. We show that a substantial proportion of IL-17A and IL-22 producing cells in the skin and blood of normal individuals and psoriasis patients are CD3-negative innate lymphocytes. Deep immunophenotyping of human ILC subsets showed a statistically significant increase in the frequency of circulating NKp44+ ILC3 in the blood of psoriasis patients compared with healthy individuals or atopic dermatitis patients. More than 50% of circulating NKp44+ ILC3 expressed cutaneous lymphocyte-associated antigen, indicating their potential for skin homing. Analysis of skin tissue revealed a significantly increased frequency of total ILCs in the skin compared with blood. Moreover, the frequency of NKp44+ ILC3 was significantly increased in non-lesional psoriatic skin compared with normal skin. A detailed time course of a psoriasis patient treated with anti-tumor necrosis factor showed a close association between therapeutic response, decrease in inflammatory skin lesions, and decrease of circulating NKp44+ ILC3. Overall, data from this initial observational study suggest a potential role for NKp44+ ILC3 in psoriasis pathogenesis.

A quartz Cherenkov detector for polarimetry at the ILC

International Nuclear Information System (INIS)

Vauth, Annika

2014-09-01

At the proposed International Linear Collider (ILC), the use of polarised electron and positron beams is a key ingredient of the physics program. A measurement of the polarisation with a yet unprecedented precision of δP / P =0.25% is required. To achieve this, Compton polarimeter measurements in front of and behind the collision point are foreseen. In this thesis, a novel concept for a detector for ILC polarimetry is introduced to eliminate one of the dominating systematics limiting the previous best measurement of beam polarisation: a detector using quartz as Cherenkov medium could increase the tolerance against non-linear photodetector responses. The high refractive index of quartz results in a higher Cherenkov light yield compared to conventional Cherenkov gases. This could allow single-peak resolution in the Cherenkov photon spectra produced by the Compton electrons at the polarimeters. The detailed simulation studies presented in this work imply that such single-peak resolution is possible. Considerations for the choice of a suitable detector geometry are discussed. A four-channel prototype has been constructed and successfully operated in a first testbeam campaign at the DESY testbeam, confirming simulation predictions. Although further studies have to be considered to quantify all aspects of the detector response, the findings of the analysis of the data from the first testbeam are promising with regards to reaching the desired light yield. In the final part of this thesis, the application of a detector concept allowing single-peak resolution to the polarisation measurement at the ILC is examined. Two of the main sources of systematic uncertainties on the polarimeter measurements are detector non-linearities and misalignments. The performance of the suggested quartz detector concept in Monte Carlo studies promises a control of these systematics which meets the precision requirements for ILC polarimetry.

Crab cavities: Past, present, and future of a challenging device

Energy Technology Data Exchange (ETDEWEB)

Wu, Q. [Brookhaven National Lab. (BNL), Upton, NY (United States)

2015-05-03

In two-ring facilities operating with a crossing-angle collision scheme, luminosity can be limited due to an incomplete overlapping of the colliding bunches. Crab cavities then are introduced to restore head-on collisions by providing the destined opposite deflection to the head and tail of the bunch. An increase in luminosity was demonstrated at KEKB with global crab-crossing, while the Large Hardron Collider (LHC) at CERN currently is designing local crab crossing for the Hi-Lumi upgrade. Future colliders may investigate both approaches. In this paper, we review the challenges in the technology, and the implementation of crab cavities, while discussing experience in earlier colliders, ongoing R&D, and proposed implementations for future facilities, such as HiLumi-LHC, CERN’s compact linear collider (CLIC), the international linear collider (ILC), and the electron-ion collider under design at BNL (eRHIC).

Crab cavities: Past, present, and future of a challenging device

International Nuclear Information System (INIS)

Wu, Q.

2015-01-01

In two-ring facilities operating with a crossing-angle collision scheme, luminosity can be limited due to an incomplete overlapping of the colliding bunches. Crab cavities then are introduced to restore head-on collisions by providing the destined opposite deflection to the head and tail of the bunch. An increase in luminosity was demonstrated at KEKB with global crab-crossing, while the Large Hardron Collider (LHC) at CERN currently is designing local crab crossing for the Hi-Lumi upgrade. Future colliders may investigate both approaches. In this paper, we review the challenges in the technology, and the implementation of crab cavities, while discussing experience in earlier colliders, ongoing R&D, and proposed implementations for future facilities, such as HiLumi-LHC, CERN@@@s compact linear collider (CLIC), the international linear collider (ILC), and the electron-ion collider under design at BNL (eRHIC).

Crab Cavities: Past, Present, and Future of a Challenging Device

CERN Document Server

Wu, Q

2015-01-01

In two-ring facilities operating with a crossing-angle collision scheme, luminosity can be limited due to an incomplete overlapping of the colliding bunches. Crab cavities then are introduced to restore head-on collisions by providing the destined opposite deflection to the head and tail of the bunch. An increase in luminosity was demonstrated at KEKB with global crab- crossing, while the Large Hardron Collider (LHC) at CERN currently is designing local crab crossing for the Hi-Lumi upgrade. Future colliders may investigate both approaches. In this paper, we review the challenges in the technology, and the implementation of crab cavities, while discussing experience in earlier colliders, ongoing R&D, and proposed implementations for future facilities, such as HiLumi-LHC, CERN’s compact linear collider (CLIC), the international linear collider (ILC), and the electronion collider under design at BNL (eRHIC).

Vertical cavity surface emitting lasers from all-inorganic perovskite quantum dots

Science.gov (United States)

Sun, Handong; Wang, Yue; Li, Xiaoming; Zeng, Haibo

We report the breakthrough in realizing the challenging while practically desirable vertical cavity surface emitting lasers (VCSELs) based on the CsPbX3 inorganic perovskite nanocrystals (IPNCs). These laser devices feature record low threshold (9 µJ/cm2), unidirectional output (beam divergence of 3.6º) and superb stability. We show that both single-mode and multimode lasing operation are achievable in the device. In contrast to traditional metal chacogenide colloidal quantum dots based lasers where the pump thresholds for the green and blue wavelengths are typically much higher than that of the red, these CsPbX3 IPNC-VCSEL devices are able to lase with comparable thresholds across the whole visible spectral range, which is appealing for achieving single source-pumped full-color lasers. We further reveal that these lasers can operate in quasi-steady state regime, which is very practical and cost-effective. Given the facile solution processibility, our CsPbX3 IPNC-VCSEL devices may hold great potential in developing low-cost yet high-performance lasers, promising in revolutionizing the vacuum-based epitaxial semiconductor lasers.

Human intrahepatic ILC2 are IL-13positive amphiregulinpositive and their frequency correlates with model of end stage liver disease score.

Directory of Open Access Journals (Sweden)

Hannah C Jeffery

Full Text Available Innate lymphoid cells (ILC have been implicated in the initiation of inflammation and fibrosis in mice. However, ILC have not been characterized in inflamed human liver tissue.Human intrahepatic lymphocytes were isolated by mechanical digestion and phenotyped by flow cytometry. Conditioned medium from cultures of primary human biliary epithelial cells, stellate cells, fibroblasts and inflamed human liver tissue was used to model the effects of the inflammatory liver environment of ILC phenotype and function.All three ILC subsets were present in the human liver, with the ILC1 (CRTH2negCD117neg subset constituting around 70% of intrahepatic ILCs. Both NCRpos (NKp44+ and NCRneg ILC3 (CRTH2negCD117pos subsets were also detected. ILC2 (CRTH2pos frequency correlated with disease severity measured by model of end stage liver disease (MELD scoring leading us to study this subset in more detail. ILC2 displayed a tissue resident CD69+ CD161++ phenotype and expressed chemokine receptor CCR6 allowing them to respond to CCL20 secreted by cholangiocytes and stellate cells. ILC2 expressed integrins VLA-5 and VLA-6 and the IL-2 and IL-7 cytokine receptors CD25 and CD127 although IL-2 and IL-7 were barely detectable in inflamed liver tissue. Although biliary epithelial cells secrete IL-33, intrahepatic ILC2 had low expression of the ST2 receptor. Intrahepatic ILC2 secreted the immunoregulatory and repair cytokines IL-13 and amphiregulin.Intrahepatic ILC2 express receptors allowing them to be recruited to bile ducts in inflamed portal tracts. Their frequencies increased with worsening liver function. Their secretion of IL-13 and amphiregulin suggests they may be recruited to promote resolution and repair and thereby they may contribute to ongoing fibrogenesis in liver disease.

Nonlinear dynamic behaviors of an optically injected vertical-cavity surface-emitting laser

International Nuclear Information System (INIS)

Li Xiaofeng; Pan Wei; Luo Bin; Ma Dong; Wang Yong; Li Nuohan

2006-01-01

Nonlinear dynamics of a vertical-cavity surface-emitting laser (VCSEL) with external optical injection are studied numerically. We consider a master-slave configuration where the dynamic characteristics of the slave are affected by the optical injection from the master, and we also establish the corresponding Simulink model. The period-doubling route as well as the period-halving route is observed, where the regular, double-periodic, and chaotic pulsings are found. By adjusting the injection strength properly, the laser can be controlled to work at a given state. The effects of frequency detuning on the nonlinear behaviors are also investigated in terms of the bifurcation diagrams of photon density with the frequency detuning. For weak injection case, the nonlinear dynamics shown by the laser are quite different when the value of frequency detuning varies contrarily (positive and negative direction). If the optical injection is strong enough, the slave can be locked by the master even though the frequency detuning is relatively large

Compact electro-absorption modulator integrated with vertical-cavity surface-emitting laser for highly efficient millimeter-wave modulation

International Nuclear Information System (INIS)

Dalir, Hamed; Ahmed, Moustafa; Bakry, Ahmed; Koyama, Fumio

2014-01-01

We demonstrate a compact electro-absorption slow-light modulator laterally-integrated with an 850 nm vertical-cavity surface-emitting laser (VCSEL), which enables highly efficient millimeter-wave modulation. We found a strong leaky travelling wave in the lateral direction between the two cavities via widening the waveguide width with a taper shape. The small signal response of the fabricated device shows a large enhancement of over 55 dB in the modulation amplitude at frequencies beyond 35 GHz; thanks to the photon-photon resonance. A large group index of over 150 in a Bragg reflector waveguide enables the resonance at millimeter wave frequencies for 25 μm long compact modulator. Based on the modeling, we expect a resonant modulation at a higher frequency of 70 GHz. The resonant modulation in a compact slow-light modulator plays a significant key role for high efficient narrow-band modulation in the millimeter wave range far beyond the intrinsic modulation bandwidth of VCSELs.

The simulation of thermal characteristics of 980 nm vertical cavity surface emitting lasers

Science.gov (United States)

Fang, Tianxiao; Cui, Bifeng; Hao, Shuai; Wang, Yang

2018-02-01

In order to design a single mode 980 nm vertical cavity surface emitting laser (VCSEL), a 2 μm output aperture is designed to guarantee the single mode output. The effects of different mesa sizes on the lattice temperature, the output power and the voltage are simulated under the condition of continuous working at room temperature, to obtain the optimum process parameters of mesa. It is obtained by results of the crosslight simulation software that the sizes of mesa radius are between 9.5 to 12.5 μm, which cannot only obtain the maximum output power, but also improve the heat dissipation of the device. Project supported by the Beijing Municipal Eduaction Commission (No. PXM2016_014204_500018) and the Construction of Scientific and Technological Innovation Service Ability in 2017 (No. PXM2017_014204_500034).

Study of Thermocurrents in ILC cavities via measurements of the Seebeck Effect in niobium, titanium, and stainless steel thermocouples

Energy Technology Data Exchange (ETDEWEB)

Cooley, Victoria [Univ. of Wisconsin, Madison, WI (United States)

2014-01-01

The goals of Fermilab’s Superconductivity and Radio Frequency Development Department are to engineer, fabricate, and improve superconducting radio frequency (SCRF) cavities in the interest of advancing accelerator technology. Improvement includes exploring possible limitations on cavity performance and mitigating such impediments. This report focuses on investigating and measuring the Seebeck Effect observed in cavity constituents titanium, niobium, and stainless steel arranged in thermocouples. These junctions exist between cavities, helium jackets, and bellows, and their connection can produce a loop of electrical current and magnetic flux spontaneously during cooling. The experimental procedure and results are described and analyzed. Implications relating the results to cavity performance are discussed.

Amplification of an Autodyne Signal in a Bistable Vertical-Cavity Surface-Emitting Laser with the Use of a Vibrational Resonance

Science.gov (United States)

Chizhevsky, V. N.

2018-01-01

For the first time, it is demonstrated experimentally that a vibrational resonance in a polarization-bistable vertical-cavity surface-emitting laser can be used to increase the laser response in autodyne detection of microvibrations from reflecting surfaces. In this case, more than 25-fold signal amplification is achieved. The influence of the asymmetry of the bistable potential on the microvibration-detection efficiency is studied.

Mid-infrared PbTe vertical external cavity surface emitting laser on Si-substrate with above 1 W output power

Science.gov (United States)

Rahim, M.; Fill, M.; Felder, F.; Chappuis, D.; Corda, M.; Zogg, H.

2009-12-01

Mid-infrared vertical external cavity surface emitting lasers (VECSELs) emitting above 1 W output power in pulsed mode and up to 17 mW in continuous mode at -172 °C were realized. Emission wavelength changes from 5 μm at -172 °C to 3.6 μm at 20 °C heat sink temperature. The active medium is a one wavelength thick PbTe layer grown by molecular beam epitaxy on a Si-substrate. It is followed by a 2.5 pair Pb1-yEuyTe/EuTe epitaxial Bragg mirror. The cavity is completed with an external curved Pb1-yEuyTe/BaF2 mirror. The VECSEL is optically pumped with 1.55 μm wavelength laser and In-soldered to Cu heat sink. No microstructural processing is needed.

Physics at the ILC

International Nuclear Information System (INIS)

Lutz, P.

2007-01-01

The seminar was an introduction to the physics studies made possible at an e + e - collider at center-of-mass energies of 500 GeV and above, like the ILC (International Linear Collider) now in discussion within the community of high energy physicists. After a brief introduction to the machine, three main topics were covered, namely Physics of the Standard Model, Physics related to the understanding of the EWSB (electroweak Symmetry Breaking) and Physics beyond the Standard Model. Before the conclusion, the attention was drawn on challenges concerning the detectors that could tackle the precision needed

Performance experience with the CEBAF SRF cavities

International Nuclear Information System (INIS)

Reece, C.; Benesch, J.; Drury, M.; Hovater, C.; Mammosser, J.; Preble, J.

1995-01-01

The full complement of 169 pairs of niobium superconducting cavities has been installed in the CEBAF accelerator. This paper surveys the performance characteristics of these cavities in vertical tests, commissioning in the tunnel, and operational experience to date. Although installed performance exceeds specifications, and 3.2 GeV beam has been delivered on target, present systems do not consistently preserve the high performance obtained in vertical dewar tests as operational capability. Principal sources of these limitations are discussed

The ILC global control system

International Nuclear Information System (INIS)

Carwardine, J.; Arnold, N.; Lenkszus, F.; Saunders, C.; Rehlich, K.; Simrock, S.; Banerjee, B.; Chase, B.; Gottschalk, E.; Joireman, P.; Kasley, P.; Lackey, S.; McBride, P.; Pavlicek, V.; Patrick, J.; Votava, M.; Wolbers, S.; Furukawa, K.; Michizono, S.; Larsen, R.S.; Downing, R.

2008-01-01

The scale and performance parameters of the ILC require new thinking in regards to control system design. This design work has begun quite early in comparison to most accelerator projects, with the goal of uniquely high overall accelerator availability. Among the design challenges are high control system availability, precision timing and rf phase reference distribution, standardizing of interfaces, operability, and maintainability. We present the current state of the design and take a prospective look at ongoing research and development projects.

Cross-Tissue Transcriptomic Analysis of Human Secondary Lymphoid Organ-Residing ILC3s Reveals a Quiescent State in the Absence of Inflammation

Directory of Open Access Journals (Sweden)

Yotam E. Bar-Ephraim

2017-10-01

Full Text Available A substantial number of human and mouse group 3 innate lymphoid cells (ILC3s reside in secondary lymphoid organs, yet the phenotype and function of these ILC3s is incompletely understood. Here, we employed an unbiased cross-tissue transcriptomic approach to compare human ILC3s from non-inflamed lymph nodes and spleen to their phenotypic counterparts in inflamed tonsils and from circulation. These analyses revealed that, in the absence of inflammation, lymphoid organ-residing ILC3s lack transcription of cytokines associated with classical ILC3 functions. This was independent of expression of the natural cytotoxicity receptor NKp44. However, and in contrast to ILC3s from peripheral blood, lymphoid organ-residing ILC3s express activating cytokine receptors and have acquired the ability to be recruited into immune responses by inflammatory cytokines. This comprehensive cross-tissue dataset will allow for identification of functional changes in human lymphoid organ ILC3s associated with human disease.

Conceptual design of 3D integrated pixel sensors for the innermost layer of the ILC vertex detector

International Nuclear Information System (INIS)

Fu, Y; Hu-Guo, C; Dorokhov, A; Zhao, W; Hu, Y; Torheim, O

2011-01-01

The paper presents a design of CMOS Pixel Sensor (CPS) using the vertical integration technology (3DIT), expected to alleviate the most essential limitations of 2D-CPS. Our objective is to develop an intelligent architecture in order to meet the requirements of the innermost layer of the International Linear Collider (ILC) vertex detectors, which are particularly demanding in spatial resolution of less than 3 μm and associated frame readout time of 10 μs. The sensor, with a pixel pitch of 23 μm, will be composed of 3-tiers Integrated Circuits (IC) with different functionalities: detection with in pixel analogue processing, pixel-level 3-bit Analogue to Digital Conversion (ADC) and fast parallel sparse readout.

5-μm vertical external-cavity surface-emitting laser (VECSEL) for spectroscopic applications

Science.gov (United States)

Rahim, M.; Khiar, A.; Felder, F.; Fill, M.; Zogg, H.; Sigrist, M. W.

2010-08-01

Mid-IR tunable VECSELs (Vertical External-Cavity Surface-Emitting Lasers) emitting at 4-7 μm wavelengths and suitable for spectroscopic sensing applications are described. They are realized with lead-chalcogenide (IV-VI) narrow band gap materials. The active part, a single 0.6-2-μm thick PbTe or PbSe gain layer, is grown onto an epitaxial Bragg mirror consisting of two or three Pb1- y Eu y Te/BaF2 quarter-wavelength layer pairs. All layers are deposited by MBE in a single run employing a BaF2 or Si substrate, no further processing is needed. The cavity is completed with an external curved top mirror, which is again realized with an epitaxial Bragg structure. Pumping is performed optically with a 1.5-μm laser. Maximum output power for pulsed operation is currently up to >1 Wp at -173°C and >10 mW at 10°C. In continuous wave (CW) operation, 18 mW at 100 K are reached. Still higher operating temperatures and/or powers are expected with better heat-removal structures and better designs employing QW (Quantum-Wells). Advantages of mid-IR VECSELs compared to edge-emitting lasers are their very good beam quality (circular beam with 15 μm are accessible with Pb1- y X y Z (X=Sr, Eu, Sn, Z=Se, Te) and/or including QW.

Lead-chalcogenide mid-infrared vertical external cavity surface emitting lasers with improved threshold: Theory and experiment

Science.gov (United States)

Fill, Matthias; Debernardi, Pierluigi; Felder, Ferdinand; Zogg, Hans

2013-11-01

Mid-infrared Vertical External Cavity Surface Emitting Lasers (VECSEL) based on narrow gap lead-chalcogenide (IV-VI) semiconductors exhibit strongly reduced threshold powers if the active layers are structured laterally for improved optical confinement. This is predicted by 3-d optical calculations; they show that lateral optical confinement is needed to counteract the anti-guiding features of IV-VIs due to their negative temperature dependence of the refractive index. An experimental proof is performed with PbSe quantum well based VECSEL grown on a Si-substrate by molecular beam epitaxy and emitting around 3.3 μm. With proper mesa-etching, the threshold intensity is about 8-times reduced.

Lead-chalcogenide mid-infrared vertical external cavity surface emitting lasers with improved threshold: Theory and experiment

Energy Technology Data Exchange (ETDEWEB)

Fill, Matthias [ETH Zurich, Laser Spectroscopy and Sensing Lab, 8093 Zurich (Switzerland); Phocone AG, 8005 Zurich (Switzerland); Debernardi, Pierluigi [IEIIT-CNR, Torino 10129 (Italy); Felder, Ferdinand [Phocone AG, 8005 Zurich (Switzerland); Zogg, Hans [ETH Zurich (Switzerland)

2013-11-11

Mid-infrared Vertical External Cavity Surface Emitting Lasers (VECSEL) based on narrow gap lead-chalcogenide (IV-VI) semiconductors exhibit strongly reduced threshold powers if the active layers are structured laterally for improved optical confinement. This is predicted by 3-d optical calculations; they show that lateral optical confinement is needed to counteract the anti-guiding features of IV-VIs due to their negative temperature dependence of the refractive index. An experimental proof is performed with PbSe quantum well based VECSEL grown on a Si-substrate by molecular beam epitaxy and emitting around 3.3 μm. With proper mesa-etching, the threshold intensity is about 8-times reduced.

Heat transfer in window frames with internal cavities

Energy Technology Data Exchange (ETDEWEB)

Gustavsen, Arild

2001-07-01

rates. From the results it appears that the thermal transmittance of a four-sided section can be found by calculating the average of the thermal transmittance of the respective single horizontal and vertical sections. In addition, it was found that two-dimensional conduction heat transfer simulation software agrees well with three-dimensional CFD simulations if the natural convection correlations used for the internal cavities are correct. Numerical simulations were done with natural convection in three-dimensional cavities with a high vertical aspect ratio and a low horizontal aspect ratio. The cavities studied had vertical aspect ratios of 20, 40, and 80 and horizontal aspect ratios ranging from 0.2 to 5. It was shown that three-dimensional cavities with a horizontal aspect ratio larger than five can be considered to be a two-dimensional cavity to within 4 % when considering heat transfer rates. Nusselt number correlations for the different horizontal aspect ratios are presented for cavities with vertical aspect ratios of 20 and 40. Complex multicellular flow was studied for the case where the vertical and horizontal aspect ratios were 40 and 2, respectively. Experimental studies included the normal spectral and total emissivity of specimens from six meter long untreated and anodized aluminum profiles. Specimens facing the internal cavities (thermal break cavity and all aluminum cavity) were measured. Some masking tapes often used in hot box experiments were also measured. The normal total emissivity was found to be is fairly constant (between 0.834 and 0.856) for exterior parts of the anodized profile and for surfaces facing the thermal break cavity. The normal total emissivity of the all-aluminum internal cavities was found to vary between 0.055 and 0.82. The experiments were performed with a Fourier transform infrared spectrometer in the wavelength interval from 4.5 to 40 mm. (author)

Flavorful Z{sup '} signatures at LHC and ILC

Energy Technology Data Exchange (ETDEWEB)

Chen, S.-L. [Department of Physics and Center for Theoretical Sciences, National Taiwan University, Taipei, Taiwan (China); Okada, Nobuchika [Department of Physics, University of Maryland, College Park, MD 20742 (United States); Theory Group, KEK, Tsukuba 305-0801 (Japan)], E-mail: okadan@post.kek.jp

2008-10-30

There are lots of new physics models which predict an extra neutral gauge boson, referred as Z{sup '}-boson. In a certain class of these new physics models, the Z{sup '}-boson has flavor-dependent couplings with the fermions in the Standard Model (SM). Based on a simple model in which couplings of the SM fermions in the third generation with the Z{sup '}-boson are different from those of the corresponding fermions in the first two generations, we study the signatures of Z{sup '}-boson at the Large Hadron Collider (LHC) and the International Linear Collider (ILC). We show that at the LHC, the Z{sup '}-boson with mass around 1 TeV can be produced through the Drell-Yan processes and its dilepton decay modes provide us clean signatures not only for the resonant production of Z{sup '}-boson but also for flavor-dependences of the production cross sections. We also study fermion pair productions at the ILC involving the virtual Z{sup '}-boson exchange. Even though the center-of-energy of the ILC is much lower than a Z{sup '}-boson mass, the angular distributions and the forward-backward asymmetries of fermion pair productions show not only sizable deviations from the SM predictions but also significant flavor-dependences.

Highly Selective Volatile Organic Compounds Breath Analysis Using a Broadly-Tunable Vertical-External-Cavity Surface-Emitting Laser.

Science.gov (United States)

Tuzson, Béla; Jágerská, Jana; Looser, Herbert; Graf, Manuel; Felder, Ferdinand; Fill, Matthias; Tappy, Luc; Emmenegger, Lukas

2017-06-20

A broadly tunable mid-infrared vertical-external-cavity surface-emitting laser (VECSEL) is employed in a direct absorption laser spectroscopic setup to measure breath acetone. The large wavelength coverage of more than 30 cm -1 at 3.38 μm allows, in addition to acetone, the simultaneous measurement of isoprene, ethanol, methanol, methane, and water. Despite the severe spectral interferences from water and alcohols, an unambiguous determination of acetone is demonstrated with a precision of 13 ppbv that is achieved after 5 min averaging at typical breath mean acetone levels in synthetic gas samples mimicking human breath.

Converter-Modulator Design and Operations for the ILC L-band Test Stand

Energy Technology Data Exchange (ETDEWEB)

Reass, William A.; /Los Alamos; Burkhart, C.; Adolphsen, Chris E.; Beukers, T.; Cassel, R.; de Lira, A.; Papas, C.; Nguyen, M.; Went, R.; /SLAC; Anderson, David E.; /Oak

2007-09-10

To facilitate a rapid response to the International Linear Collider (ILC) L-band development program at SLAC, a spare converter-modulator was shipped from LANL. This modulator was to be a spare for the spallation neutron source (SNS) accelerator at ORNL. The ILC application requires a 33% higher peak output power (15 MW) and output current (120 Amp). This presents significant design challenges to modify the existing hardware and yet maintain switching parameters and thermal cycling within the semiconductor component ratings. To minimize IGBT commutation and free-wheeling diode currents, a different set of optimizations, as compared to the SNS design, were used to tune the resonant switching networks. Additional complexities arose as nanocrystalline cores with different performance characteristics (as compared to SNS), were used to fabricate the resonant 'boost' transformers. This paper will describe the electrical design, modeling efforts, and resulting electrical performance as implemented for the ILC L-band test stand.

PbSe quantum well mid-infrared vertical external cavity surface emitting laser on Si-substrates

Science.gov (United States)

Fill, M.; Khiar, A.; Rahim, M.; Felder, F.; Zogg, H.

2011-05-01

Mid-infrared vertical external cavity surface emitting lasers based on PbSe/PbSrSe multi-quantum-well structures on Si-substrates are realized. A modular design allows growing the active region and the bottom Bragg mirror on two different Si-substrates, thus facilitating comparison between different structures. Lasing is observed from 3.3 to 5.1 μm wavelength and up to 52 °C heat sink temperature with 1.55 μm optical pumping. Simulations show that threshold powers are limited by Shockley-Read recombination with lifetimes as short as 0.1 ns. At higher temperatures, an additional threshold power increase occurs probably due to limited carrier diffusion length and carrier leakage, caused by an unfavorable band alignment.

Higgs boson production in the littlest Higgs model with T-parity at the ILC

Science.gov (United States)

Han, Jinzhong; Yang, Guang; Meng, Ming; Wang, Weijian; Li, Jingyun

2018-04-01

We investigate the Higgs boson production processes e+e‑→ ZH, e+e‑→ νν¯H, e+e‑→ tt¯H, e+e‑→ ZHH and e+e‑→ νν¯HH in the littlest Higgs model with T-parity (LHT) at the International Linear Collider (ILC). We calculate the LHT model predictions on the production rate of these processes at the ILC in the case of (un)polarized beams and the signal strengths of the production processes ZH and νν¯H with Higgs decaying to bb¯(gg,γγ). In the allowed parameter space, we find that the signal strengths μgg is most likely approach to the expected precision of the ILC.

Performance of a reentrant cavity beam position monitor

Directory of Open Access Journals (Sweden)

Claire Simon

2008-08-01

Full Text Available The beam-based alignment and feedback systems, essential operations for the future colliders, require high resolution beam position monitors (BPMs. In the framework of the European CARE/SRF program, a reentrant cavity BPM with its associated electronics was developed by the CEA/DSM/Irfu in collaboration with DESY. The design, the fabrication, and the beam test of this monitor are detailed within this paper. This BPM is designed to be inserted in a cryomodule, work at cryogenic temperature in a clean environment. It has achieved a resolution better than 10  μm and has the possibility to perform bunch to bunch measurements for the x-ray free electron laser (X-FEL and the International Linear Collider (ILC. Its other features are a small size of the rf cavity, a large aperture (78 mm, and an excellent linearity. A first prototype of a reentrant cavity BPM was installed in the free electron laser in Hamburg (FLASH, at Deutsches Elektronen-Synchrotron (DESY and demonstrated its operation at cryogenic temperature inside a cryomodule. The second, installed, also, in the FLASH linac to be tested with beam, measured a resolution of approximately 4  μm over a dynamic range ±5  mm in single bunch.

Performance of a reentrant cavity beam position monitor

International Nuclear Information System (INIS)

Simon, C.; Luong, M.; Chel, S.; Napoly, O.; Novo, J.; Roudier, D.; Rouviere, N.; Baboi, N.; Mildner, N.; Nolle, D.

2008-01-01

The beam-based alignment and feedback systems, essential operations for the future colliders, require high resolution beam position monitors (BPMs). In the framework of the European CARE/SRF program, a reentrant cavity BPM with its associated electronics was developed by the CEA/DSM/Irfu in collaboration with DESY. The design, the fabrication, and the beam test of this monitor are detailed within this paper. This BPM is designed to be inserted in a cryo-module, work at cryogenic temperature in a clean environment. It has achieved a resolution better than 10 μm and has the possibility to perform bunch to bunch measurements for the X-ray free electron laser (X-FEL) and the International Linear Collider (ILC). Its other features are a small size of the rf cavity, a large aperture (78 mm), and an excellent linearity. A first prototype of a reentrant cavity BPM was installed in the free electron laser in Hamburg (FLASH), at Deutsches Elektronen-Synchrotron (DESY) and demonstrated its operation at cryogenic temperature inside a cryo-module. The second, installed, also, in the FLASH linac to be tested with beam, measured a resolution of approximately 4 μm over a dynamic range ± 5 mm in single bunch. (authors)

Performance of a reentrant cavity beam position monitor

Science.gov (United States)

Simon, Claire; Luong, Michel; Chel, Stéphane; Napoly, Olivier; Novo, Jorge; Roudier, Dominique; Rouvière, Nelly; Baboi, Nicoleta; Mildner, Nils; Nölle, Dirk

2008-08-01

The beam-based alignment and feedback systems, essential operations for the future colliders, require high resolution beam position monitors (BPMs). In the framework of the European CARE/SRF program, a reentrant cavity BPM with its associated electronics was developed by the CEA/DSM/Irfu in collaboration with DESY. The design, the fabrication, and the beam test of this monitor are detailed within this paper. This BPM is designed to be inserted in a cryomodule, work at cryogenic temperature in a clean environment. It has achieved a resolution better than 10μm and has the possibility to perform bunch to bunch measurements for the x-ray free electron laser (X-FEL) and the International Linear Collider (ILC). Its other features are a small size of the rf cavity, a large aperture (78 mm), and an excellent linearity. A first prototype of a reentrant cavity BPM was installed in the free electron laser in Hamburg (FLASH), at Deutsches Elektronen-Synchrotron (DESY) and demonstrated its operation at cryogenic temperature inside a cryomodule. The second, installed, also, in the FLASH linac to be tested with beam, measured a resolution of approximately 4μm over a dynamic range ±5mm in single bunch.

Heat and mass transfer in porous cavity: Assisting flow

Energy Technology Data Exchange (ETDEWEB)

Badruddin, Irfan Anjum [Dept. of Mechanical Engineering, University of Malaya, Kuala Lumpur, 50603 (Malaysia); Quadir, G. A. [School of Mechatronic Engineering, University Malaysia Perlis, Pauh Putra, 02600 Arau, Perlis (Malaysia)

2016-06-08

In this paper, investigation of heat and mass transfer in a porous cavity is carried out. The governing partial differential equations are non-dimensionalised and solved using finite element method. The left vertical surface of the cavity is maintained at constant temperature and concentration which are higher than the ambient temperature and concentration applied at right vertical surface. The top and bottom walls of the cavity are adiabatic. Heat transfer is assumed to take place by natural convection and radiation. The investigation is carried out for assisting flow when buoyancy and gravity force act in same direction.

Electropolishing on single-cell: (TESLA, Reentrant and Low Loss shapes) Comsol modelling

International Nuclear Information System (INIS)

Bruchon, M.

2007-01-01

In the framework of improvement of cavity electropolishing, modelling permits to evaluate some parameters not easily accessible by experiments and can also help us to guide them. Different laboratories (DESY, Fermilab) work on electro or chemical polishing modelling with different approaches and softwares. At CEA Saclay, COMSOL software is used to model horizontal electropolishing of cavity in two dimensions. The goal of this study has been motivated by improvement of our electropolishing setup by modifying the arrival of the acid. The influence of a protuberant cathode has been evaluated and compared for different shapes of single cell cavities: TESLA, ILC Low Loss (LL ILC ), and ILC Reentrant (RE ILC ). (author)

UK pulls out of plans for ILC

CERN Multimedia

Durrani, Matin

2007-01-01

"A funding crisis at one of the UK's leading research councils has forced the country to pull out of plans for the International Linear Collider (ILC). The science and Technology Facilities Council (STFC) says in a report published today that it does not see "a practicable path towards the realization of this facility as currently conceived on a reasonable timescale". (1 page)

ILC Instrumentation R and D at SCIPP

International Nuclear Information System (INIS)

Carman, J.; Crosby, S.; Fadeyev, V.; Schumm, B.A.; Spencer, N.; Wilder, M.; Partridge, R.

2011-01-01

The Santa Cruz Institute for Particle Physics (SCIPP) continues to be engaged in research and development towards an ILC detector. The latest efforts at SCIPP are described, including those associated with the LSTFE front-end readout ASIC, the use of charge division to obtain a longitudinal coordinate from silicon strip detectors, and the contribution of strip resistance to readout noise.

The potential of the ILC for discovering new particles

Energy Technology Data Exchange (ETDEWEB)

Fujii, Keisuke [High Energy Accelerator Research Organization (KEK), Ibaraki (Japan); Grojean, Christophe [DESY, Hamburg (Germany); Humboldt-Univ., Berlin (Germany). Inst. fuer Physik; ICREA, Barcelona (Spain); Peskin, Michael E. [Stanford Univ., Menlo Park, CA (United States). SLAC; Collaboration: LCC Physics Working Group; and others

2017-02-15

This paper addresses the question of whether the International Linear Collider has the capability of discovering new particles that have not already been discovered at the CERN Large Hadron Collider. We summarize the various paths to discovery offered by the ILC, and discuss them in the context of three different scenarios: 1. LHC does not discover any new particles, 2. LHC discovers some new low mass states and 3. LHC discovers new heavy particles. We will show that in each case, ILC plays a critical role in discovery of new phenomena and in pushing forward the frontiers of high-energy physics as well as our understanding of the universe in a manner which is highly complementary to that of LHC. For the busy reader, a two-page executive summary is provided at the beginning of the document.

The potential of the ILC for discovering new particles

International Nuclear Information System (INIS)

Fujii, Keisuke; Grojean, Christophe; Peskin, Michael E.

2017-02-01

This paper addresses the question of whether the International Linear Collider has the capability of discovering new particles that have not already been discovered at the CERN Large Hadron Collider. We summarize the various paths to discovery offered by the ILC, and discuss them in the context of three different scenarios: 1. LHC does not discover any new particles, 2. LHC discovers some new low mass states and 3. LHC discovers new heavy particles. We will show that in each case, ILC plays a critical role in discovery of new phenomena and in pushing forward the frontiers of high-energy physics as well as our understanding of the universe in a manner which is highly complementary to that of LHC. For the busy reader, a two-page executive summary is provided at the beginning of the document.

Determination of new electroweak parameters at the ILC. Sensitivity to new physics

Energy Technology Data Exchange (ETDEWEB)

Beyer, M.; Schmidt, E.; Schroeder, H. [Rostock Univ. (Germany). Inst. fuer Physik; Kilian, W. [Siegen Univ. (Gesamthochschule) (Germany). Fach Physik]|[Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Krstonosic, P.; Reuter, J. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Moenig, K. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

2006-04-15

We present a study of the sensitivity of an International Linear Collider (ILC) to electroweak parameters in the absence of a light Higgs boson. In particular, we consider those parameters that have been inaccessible at previous colliders, quartic gauge couplings. Within a generic effective-field theory context we analyze all processes that contain quasi-elastic weak-boson scattering, using complete six-fermion matrix elements in unweighted event samples, fast simulation of the ILC detector, and a multidimensional parameter fit of the set of anomalous couplings. The analysis does not rely on simplifying assumptions such as custodial symmetry or approximations such as the equivalence theorem. We supplement this by a similar new study of triple weak-boson production, which is sensitive to the same set of anomalous couplings. Including the known results on triple gauge couplings and oblique corrections, we thus quantitatively determine the indirect sensitivity of the ILC to new physics in the electroweak symmetry-breaking sector, conveniently parameterized by real or fictitious resonances in each accessible spin/isospin channel. (Orig.)

Determination of new electroweak parameters at the ILC. Sensitivity to new physics

International Nuclear Information System (INIS)

Beyer, M.; Schmidt, E.; Schroeder, H.; Krstonosic, P.; Reuter, J.; Moenig, K.

2006-04-01

We present a study of the sensitivity of an International Linear Collider (ILC) to electroweak parameters in the absence of a light Higgs boson. In particular, we consider those parameters that have been inaccessible at previous colliders, quartic gauge couplings. Within a generic effective-field theory context we analyze all processes that contain quasi-elastic weak-boson scattering, using complete six-fermion matrix elements in unweighted event samples, fast simulation of the ILC detector, and a multidimensional parameter fit of the set of anomalous couplings. The analysis does not rely on simplifying assumptions such as custodial symmetry or approximations such as the equivalence theorem. We supplement this by a similar new study of triple weak-boson production, which is sensitive to the same set of anomalous couplings. Including the known results on triple gauge couplings and oblique corrections, we thus quantitatively determine the indirect sensitivity of the ILC to new physics in the electroweak symmetry-breaking sector, conveniently parameterized by real or fictitious resonances in each accessible spin/isospin channel. (Orig.)

Coherent Instabilities of ILC Damping Ring

Energy Technology Data Exchange (ETDEWEB)

Heifets, S.; Stupakov, G.; Bane, K.; /SLAC

2006-09-27

The paper presents the first attempt to estimates the ILC damping ring impedance and compare thresholds of the classical instabilities for several designs initially proposed for the DR. The work was carried out in the spring of 2006. Since then the choice of the DR is narrowed. Nevertheless, the analysis described may be useful for the next iterations of the beam stability. Overall, the conventional instabilities will have little impact on the ring performance provided the careful design of the ring minimizes the impedance below acceptable level indicated above. The only exception is the transverse CB instability. The longitudinal CB is less demanding. However, even the transverse CB instability would have threshold current above nominal provided the aperture in the wigglers is increased from 8 mm to 16 mm. The microwave instability needs more studies. Nevertheless, we should remember that the ILC DR is different from existing high-current machines at least in two respects: absence of the beam-beam tune spread stabilizing beams in colliders, and unusual strict requirements for low emittance. That may cause new problems such as bunch emittance dilution due to high-frequency wakes (BPMs, grooves), etc. Even if such a possibility exists, it probably universal for all machines and ought be addressed in the design of vacuum components rather than have effect on the choice of the machine design.

Vertical Cavity Surface Emitting Laser for Operation at 1.5 µm with Integral AlGaInAs/InP Bragg mirrors

OpenAIRE

Linnik, M.; Christou, A.

2001-01-01

The design and performance of a low threshold selectively oxidized Vertical Cavity Surface Emitting Laser (VCSEL) fabricated for operation at a wavelength of 1.55 µm is based on III-V quaternary semiconductor alloys and is grown by Molecular Beam Epitaxy technique. The theoretical investigation of the optical properties of the compound semiconductor alloys allows one to select the optimum materials for highly reflective Bragg mirrors. The simulation of the designed VCSEL performance has been ...

Self-sustained pulsation in the oxide-confined vertical-cavity surface-emitting lasers based on submonolayer InGaAs quantum dots

International Nuclear Information System (INIS)

Kuzmenkov, A. G.; Ustinov, V. M.; Sokolovskii, G. S.; Maleev, N. A.; Blokhin, S. A.; Deryagin, A. G.; Chumak, S. V.; Shulenkov, A. S.; Mikhrin, S. S.; Kovsh, A. R.; McRobbie, A. D.; Sibbett, W.; Cataluna, M. A.; Rafailov, E. U.

2007-01-01

The authors report the observation of strong self-pulsations in molecular-beam epitaxy-grown oxide-confined vertical-cavity surface-emitting lasers based on submonolayer InGaAs quantum dots. At continuous-wave operation, self-pulsations with pulse durations of 100-300 ps and repetition rates of 0.2-0.6 GHz were measured. The average optical power of the pulsations was 0.5-1.0 mW at the laser continuous-wave current values of 1.5-2.5 mA

Single-mode temperature and polarisation-stable high-speed 850nm vertical cavity surface emitting lasers

International Nuclear Information System (INIS)

Nazaruk, D E; Blokhin, S A; Maleev, N A; Bobrov, M A; Pavlov, M M; Kulagina, M M; Vashanova, K A; Zadiranov, Yu M; Ustinov, V M; Kuzmenkov, A G; Vasil'ev, A P; Gladyshev, A G; Blokhin, A A; Salut, 7 Larina Str, N Novgorod, 603950 (Russian Federation))" data-affiliation=" (JSV Salut, 7 Larina Str, N Novgorod, 603950 (Russian Federation))" >Fefelov, A G

2014-01-01

A new intracavity-contacted design to realize temperature and polarization-stable high-speed single-mode 850 nm vertical cavity surface emitting lasers (VCSELs) grown by molecular-beam epitaxy is proposed. Temperature dependences of static and dynamic characteristics of the 4.5 pm oxide aperture InGaAlAs VCSEL were investigated in detail. Due to optimal gain-cavity detuning and enhanced carrier localization in the active region the threshold current remains below 0.75 mA for the temperature range within 20-90°C, while the output power exceeds 1 mW up to 90°C. Single-mode operation with side-mode suppression ratio higher than 30 dB and orthogonal polarization suppression ratio more than 18 dB was obtained in the whole current and temperature operation range. Device demonstrates serial resistance less than 250 Ohm, which is rather low for any type of single-mode short- wavelength VCSELs. VCSEL demonstrates temperature robust high-speed operation with modulation bandwidth higher than 13 GHz in the entire temperature range of 20-90°C. Despite high resonance frequency the high-speed performance of developed VCSELs was limited by the cut-off frequency of the parasitic low pass filter created by device resistances and capacitances. The proposed design is promising for single-mode high-speed VCSEL applications in a wide spectral range

Automated Surface Classification of SRF Cavities for the Investigation of the Influence of Surface Properties onto the Operational Performance

Energy Technology Data Exchange (ETDEWEB)

Wenskat, Marc

2015-07-15

Superconducting niobium radio-frequency cavities are fundamental for the European XFEL and the International Linear Collider. To use the operational advantages of superconducting cavities, the inner surface has to fulfill quite demanding requirements. The surface roughness and cleanliness improved over the last decades and with them, the achieved maximal accelerating field. Still, limitations of the maximal achieved accelerating field are observed, which are not explained by localized geometrical defects or impurities. The scope of this thesis is a better understanding of these limitations in defect free cavities based on global, rather than local, surface properties. For this goal, more than 30 cavities underwent subsequent surface treatments, cold RF tests and optical inspections within the ILC-HiGrade research program and the XFEL cavity production. An algorithm was developed which allows an automated surface characterization based on an optical inspection robot. This algorithm delivers a set of optical surface properties, which describes the inner cavity surface. These optical surface properties deliver a framework for a quality assurance of the fabrication procedures. Furthermore, they shows promising results for a better understanding of the observed limitations in defect free cavities.

Automated Surface Classification of SRF Cavities for the Investigation of the Influence of Surface Properties onto the Operational Performance

International Nuclear Information System (INIS)

Wenskat, Marc

2015-07-01

Superconducting niobium radio-frequency cavities are fundamental for the European XFEL and the International Linear Collider. To use the operational advantages of superconducting cavities, the inner surface has to fulfill quite demanding requirements. The surface roughness and cleanliness improved over the last decades and with them, the achieved maximal accelerating field. Still, limitations of the maximal achieved accelerating field are observed, which are not explained by localized geometrical defects or impurities. The scope of this thesis is a better understanding of these limitations in defect free cavities based on global, rather than local, surface properties. For this goal, more than 30 cavities underwent subsequent surface treatments, cold RF tests and optical inspections within the ILC-HiGrade research program and the XFEL cavity production. An algorithm was developed which allows an automated surface characterization based on an optical inspection robot. This algorithm delivers a set of optical surface properties, which describes the inner cavity surface. These optical surface properties deliver a framework for a quality assurance of the fabrication procedures. Furthermore, they shows promising results for a better understanding of the observed limitations in defect free cavities.

Beam-induced backgrounds in detectors at the ILC

Energy Technology Data Exchange (ETDEWEB)

Vogel, Adrian

2008-11-15

There is general consensus in the high-energy physics community that the next particle collider to be built should be a linear electron-positron accelerator. Such a machine, colliding point-like particles with a well-defined initial state, would be an ideal complement to the Large Hadron Collider (LHC) and would allow high-precision measurements of the new physics phenomena that are likely to be discovered at the TeV energy scale. The most advanced project in that context is the International Linear Collider (ILC), aiming for a centre-of-mass energy of 500 GeV and a luminosity of 2 x 10{sup 34} cm{sup -2}s{sup -1} in its first stage. One of the detector concepts that are currently being developed and studied is the so-called International Large Detector (ILD). A prime feature of the ILD concept is the usage of a Time Projection Chamber (TPC) as the main tracker, which allows to reach the required momentum resolution, but which also has excellent particle identification capabilities and a highly robust and efficient tracking. The beam-beam interaction of the strongly focused particle bunches at the ILC will produce beamstrahlung photons, which can in turn scatter to electron-positron pairs. These pairs are a major source of detector backgrounds. This thesis explains the methods to study the effects of beam-induced electron-positron pair backgrounds with Mokka, a full detector simulation for the ILC that is based on Geant4, and it presents the simulation results for different detector configurations and various small modifications. The main focus of the simulations and their analysis is on the vertex detector and the TPC, but results for the inner silicon trackers and the hadronic calorimeters are shown as well. (orig.)

Beam-induced backgrounds in detectors at the ILC

International Nuclear Information System (INIS)

Vogel, Adrian

2008-11-01

There is general consensus in the high-energy physics community that the next particle collider to be built should be a linear electron-positron accelerator. Such a machine, colliding point-like particles with a well-defined initial state, would be an ideal complement to the Large Hadron Collider (LHC) and would allow high-precision measurements of the new physics phenomena that are likely to be discovered at the TeV energy scale. The most advanced project in that context is the International Linear Collider (ILC), aiming for a centre-of-mass energy of 500 GeV and a luminosity of 2 x 10 34 cm -2 s -1 in its first stage. One of the detector concepts that are currently being developed and studied is the so-called International Large Detector (ILD). A prime feature of the ILD concept is the usage of a Time Projection Chamber (TPC) as the main tracker, which allows to reach the required momentum resolution, but which also has excellent particle identification capabilities and a highly robust and efficient tracking. The beam-beam interaction of the strongly focused particle bunches at the ILC will produce beamstrahlung photons, which can in turn scatter to electron-positron pairs. These pairs are a major source of detector backgrounds. This thesis explains the methods to study the effects of beam-induced electron-positron pair backgrounds with Mokka, a full detector simulation for the ILC that is based on Geant4, and it presents the simulation results for different detector configurations and various small modifications. The main focus of the simulations and their analysis is on the vertex detector and the TPC, but results for the inner silicon trackers and the hadronic calorimeters are shown as well. (orig.)

Physics Interplay of the LHC and the ILC

Energy Technology Data Exchange (ETDEWEB)

Weiglein, G.

2004-12-17

Physics at the Large Hadron Collider (LHC) and the International e{sup +}e{sup -} Linear Collider (ILC)will be complementary in many respects, as has been demonstrated at previous generations of hadron and lepton colliders. This report addresses the possible interplay between the LHC and ILC in testing the Standard Model and in discovering and determining the origin of new physics. Mutual benefits for the physics programme at both machines can occur both at the level of a combined interpretation of Hadron Collider and Linear Collider data and at the level of combined analyses of the data, where results obtained at one machine can directly influence the way analyses are carried out at the other machine. Topics under study comprise the physics of weak and strong electroweak symmetry breaking, supersymmetric models, new gauge theories, models with extra dimensions, and electroweak and QCD precision physics. The status of the work that has been carried out within the LHC/LC Study Group so far is summarized in this report. Possible topics for future studies are outlined.

Discriminating leptonic Yukawa interactions with doubly charged scalar at the ILC

Science.gov (United States)

Nomura, Takaaki; Okada, Hiroshi; Yokoya, Hiroshi

2018-04-01

We explore discrimination of two types of leptonic Yukawa interactions associated with Higgs triplet, LbarLc ΔLL, and with SU (2) singlet doubly charged scalar, ebarRc k++eR. These interactions can be distinguished by measuring the effects of doubly charged scalar boson exchange in the e+e- →ℓ+ℓ- processes at polarized electron-positron colliders. We study a forward-backward asymmetry of scattering angular distribution to estimate the sensitivity for these effects at the ILC. In addition, we investigate prospects of upper bounds on the Yukawa couplings by combining the constraints of lepton flavor violation processes and the e+e- →ℓ+ℓ- processes at the LEP and the ILC.

Critical role of fatty acid metabolism in ILC2 mediated barrier protection during malnutrition and helminth infection

Science.gov (United States)

Innate lymphoid cells (ILCs) play an important role in many immune processes, including control of infections, inflammation and tissue repair. To date little is known about the metabolism of ILCs under steady-state conditions and infection, and whether these cells can metabolically adapt in response...

Development of a compact vertical-cavity surface-emitting laser end-pumped actively Q-switched laser for laser-induced breakdown spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Li, Shuo; Chen, Rongzhang; Nelsen, Bryan; Chen, Kevin, E-mail: pec9@pitt.edu [Department of Electrical and Computer Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States); Liu, Lei; Huang, Xi; Lu, Yongfeng [Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588 (United States)

2016-03-15

This paper reports the development of a compact and portable actively Q-switched Nd:YAG laser and its applications in laser-induced breakdown spectroscopy (LIBS). The laser was end-pumped by a vertical-cavity surface-emitting laser (VCSEL). The cavity lases at a wavelength of 1064 nm and produced pulses of 16 ns with a maximum pulse energy of 12.9 mJ. The laser exhibits a reliable performance in terms of pulse-to-pulse stability and timing jitter. The LIBS experiments were carried out using this laser on NIST standard alloy samples. Shot-to-shot LIBS signal stability, crater profile, time evolution of emission spectra, plasma electron density and temperature, and limits of detection were studied and reported in this paper. The test results demonstrate that the VCSEL-pumped solid-state laser is an effective and compact laser tool for laser remote sensing applications.

Injection molding of micro pillars on vertical side walls using polyether-ether-ketone (PEEK)

DEFF Research Database (Denmark)

Zhang, Yang; Hansen, Hans Nørgaard; Sørensen, Søren

2016-01-01

This paper investigates the replication of microstructures on a vertical wall by PEEK injection molding. A 4-cavity insert was used in the injection molding. Pre-fabricated nickel plates with ø 4 μm micro holes on the surface were glued on vertical walls in the cavities. 3 cavities were coated by...

Metasurface external cavity laser

Energy Technology Data Exchange (ETDEWEB)

Xu, Luyao, E-mail: luyaoxu.ee@ucla.edu; Curwen, Christopher A.; Williams, Benjamin S. [Department of Electrical Engineering, University of California, Los Angeles, California 90095 (United States); California NanoSystems Institute, University of California, Los Angeles, California 90095 (United States); Hon, Philip W. C.; Itoh, Tatsuo [Department of Electrical Engineering, University of California, Los Angeles, California 90095 (United States); Chen, Qi-Sheng [Northrop Grumman Aerospace Systems, Redondo Beach, California 90278 (United States)

2015-11-30

A vertical-external-cavity surface-emitting-laser is demonstrated in the terahertz range, which is based upon an amplifying metasurface reflector composed of a sub-wavelength array of antenna-coupled quantum-cascade sub-cavities. Lasing is possible when the metasurface reflector is placed into a low-loss external cavity such that the external cavity—not the sub-cavities—determines the beam properties. A near-Gaussian beam of 4.3° × 5.1° divergence is observed and an output power level >5 mW is achieved. The polarized response of the metasurface allows the use of a wire-grid polarizer as an output coupler that is continuously tunable.

An Intelligent Lighting Control System (ILCS) using LabVIEW ...

African Journals Online (AJOL)

An Intelligent Lighting Control System (ILCS) was proposed and designed by considering ergonomic setting and energy efficiency. The integration of CompactRIO as a main hardware and National Instrument Laboratory Virtual Instrument Engineering Workbench (NI LabVIEW) 2012 as a platform to design an interactive ...

Lithographic wavelength control of an external cavity laser with a silicon photonic crystal cavity-based resonant reflector.

Science.gov (United States)

Liles, Alexandros A; Debnath, Kapil; O'Faolain, Liam

2016-03-01

We report the experimental demonstration of a new design for external cavity hybrid lasers consisting of a III-V semiconductor optical amplifier (SOA) with fiber reflector and a photonic crystal (PhC)-based resonant reflector on SOI. The silicon reflector is composed of an SU8 polymer bus waveguide vertically coupled to a PhC cavity and provides a wavelength-selective optical feedback to the laser cavity. This device exhibits milliwatt-level output power and side-mode suppression ratios of more than 25 dB.

The Murine Natural Cytotoxic Receptor NKp46/NCR1 Controls TRAIL Protein Expression in NK Cells and ILC1s

Directory of Open Access Journals (Sweden)

Sam Sheppard

2018-03-01

Full Text Available Summary: TRAIL is an apoptosis-inducing ligand constitutively expressed on liver-resident type 1 innate lymphoid cells (ILC1s and a subset of natural killer (NK cells, where it contributes to NK cell anti-tumor, anti-viral, and immunoregulatory functions. However, the intrinsic pathways involved in TRAIL expression in ILCs remain unclear. Here, we demonstrate that the murine natural cytotoxic receptor mNKp46/NCR1, expressed on ILC1s and NK cells, controls TRAIL protein expression. Using NKp46-deficient mice, we show that ILC1s lack constitutive expression of TRAIL protein and that NK cells activated in vitro and in vivo fail to upregulate cell surface TRAIL in the absence of NKp46. We show that NKp46 regulates TRAIL expression in a dose-dependent manner and that the reintroduction of NKp46 in mature NK cells deficient for NKp46 is sufficient to restore TRAIL surface expression. These studies uncover a link between NKp46 and TRAIL expression in ILCs with potential implications in pathologies involving NKp46-expressing cells. : Sheppard et al. find that mice deficient in the activating receptor NCR1/NKp46 (Ncr1−/− fail to express the apoptosis-inducing ligand TRAIL at the surface of group 1 innate lymphoid cells (ILC1s. Keywords: NK cell, natural killer cell, NKp46, ILC1, TRAIL, IL-15, IL-2

Fast pulsing dynamics of a vertical-cavity surface-emitting laser operating in the low-frequency fluctuation regime

International Nuclear Information System (INIS)

Sciamanna, M.; Rogister, F.; Megret, P.; Blondel, M.; Masoller, C.; Abraham, N. B.

2003-01-01

We analyze the dynamics of a vertical-cavity surface-emitting laser with optical feedback operating in the low-frequency fluctuation regime. By focusing on the fast pulsing dynamics, we show that the two linearly polarized modes of the laser exhibit two qualitatively different behaviors: they emit pulses in phase just after a power dropout and they emit pulses out of phase after the recovery process of the output power. As a consequence, two distinct statistical distributions of the fast pulsating total intensity are observed, either monotonically decaying from the noise level or peaked around the mean intensity value. We further show that gain self-saturation of the lasing transition strongly modifies the shape of the intensity distribution

Simplified SUSY at the ILC

International Nuclear Information System (INIS)

Berggren, Mikael

2013-08-01

At the ILC, one has the possibility to search for SUSY in an model-independent way: The corner-stone of SUSY is that sparticles couple as particles. This is independent of the mechanism responsible for SUSY breaking. Any model will have one Lightest SUSY Particle (LSP), and one Next to Lightest SUSY Particle (NLSP). In models with conserved R-parity, the NLSP must decay solely to the LSP and the SM partner of the NLSP. Therefore, studying NLSP production and decay can be regarded as a ''simplified model without simplification'': Any SUSY model will have such a process. The NLSP could be any sparticle: a slepton, an electroweak-ino, or even a squark. However, since there are only a finite number of sparticles, one can systematically search for signals of all possible NLSP:s. This way, the entire space of models that have a kinematically reachable NLSP can be covered. For any NLSP, the ''worst case'' can be determined, since the SUSY principle allows to calculate the cross-section once the NLSP nature and mass are given. The region in the LSP-NLSP mass-plane where the ''worst case'' could be discovered or excluded experimentally can be found by estimating background and efficiency at each point in the plane. From experience at LEP, it is expected that the lower signal-to background ratio will indeed be found for models with conserved R-parity. In this document, we show that at the ILC, such a program is possible, as it was at LEP. No loop-holes are left, even for difficult or non-standard cases: whatever the NLSP is it will be detectable.

New Methods for Thin Film Deposition and First Investigations of the use of High Temperature Superconductors for Thin Film Cavities

CERN Document Server

Gustafsson, Anna; Vollenberg, Wilhelmus; Seviour, Rebecca

2010-01-01

Niobium thin film cavities have shown good and reliable performance for LEP and LHC, although there are limitations to overcome if this technique should be used for new accelerators such as the ILC. New coating techniques like High Power Impulse Magnetron Sputtering (HiPIMS) has shown very promising results and we will report on its possible improvements for Nb thin film cavity performance. Current materials used in accelerator Superconducting Radio Frequency (SRF) technologies operate at temperatures below 4 K, which require complex cryogenic systems. Researchers have investigated the use of High Temperature Superconductors (HTS) to form RF cavities, with limited success. We propose a new approach to achieve a high-temperature SRF cavity based on the superconducting ’proximity effect’. The superconducting proximity effect is the effect through which a superconducting material in close proximity to a non-superconducting material induces a superconducting condensate in the latter. Using this effect we hope...

Inverse type II seesaw mechanism and its signature at the LHC and ILC

Energy Technology Data Exchange (ETDEWEB)

Freitas, F.F.; Pires, C.A. de S, E-mail: cpires@fisica.ufpb.br; Rodrigues da Silva, P.S.

2017-06-10

The advent of the LHC, and the proposal of building future colliders as the ILC, both programmed to explore new physics at the TeV scale, justify the recent interest in collider phenomenology of seesaw mechanisms whose signatures lie on TeV scale or less. The most popular TeV scale seesaw mechanisms are the inverse seesaw ones. There are three types of inverse seesaw mechanisms, but only that one implemented in an arrangement involving six non-standard heavy neutrinos has received attention. In this paper we develop an inverse seesaw mechanism based on Higgs triplet model and simulate its collider phenomenology by producing doubly charged Higgses at the LHC and ILC and analyzing their subsequent decays in pair of leptons. We find that although the new scalars decouple from the standard ones, signals of these scalars may be detected in the current run of the LHC or in the future ILC. Our simulations probe the model in the region of parameter space that generates the correct neutrino masses and mixing for both normal and inverted hierarchy cases.

Beam dynamic simulations of the CLIC crab cavity and implications on the BDS

Energy Technology Data Exchange (ETDEWEB)

Shinton, I.R.R., E-mail: ian.shinton@stfc.ac.uk [School of Physics and Astronomy, University of Manchester, Manchester (United Kingdom); Cockcroft Institute of Accelerator Science and Technology, Daresbury (United Kingdom); Burt, G. [Engineering Department, Lancaster University, Lancaster (United Kingdom); Cockcroft Institute of Accelerator Science and Technology, Daresbury (United Kingdom); Glasman, C.J.; Jones, R.M. [School of Physics and Astronomy, University of Manchester, Manchester (United Kingdom); Cockcroft Institute of Accelerator Science and Technology, Daresbury (United Kingdom); Wolski, A. [Department of Physics, University of Liverpool, Liverpool (United Kingdom); Cockcroft Institute of Accelerator Science and Technology, Daresbury (United Kingdom)

2011-11-21

The Compact Linear Collider (CLIC) is a proposed electron positron linear collider design aiming to achieve a centre of mass energy of up to 3 TeV. The main accelerating structures in CLIC operate at an X-band frequency of 11.994 GHz with an accelerating gradient of 100 MV/m. The present design requires the beams to collide at a small crossing angle of 10 mrad per line giving a resultant overall crossing angle of 20 mrad. Transverse deflecting cavities, referred to as 'Crab cavities', are installed in the beam delivery system (BDS) of linear collider designs in order to ensure the final luminosity at the interaction point (IP) is comparable to that in a head on collision. We utilise the beam tracking code PLACET combined with the beam-beam code GUINEA-PIG to calculate the resulting luminosity at the IP. We follow a similar tuning procedure to that used for the design of the ILC crab cavities and anitcrab cavities. However an unexpected loss in luminosity of 10% was observed for the 20 mrad design was observed. It was discovered that the action of the crab cavities can affect the geometric aberrations resulting from the sextupoles used to correct chromatic effects in the beam delivery system. This has direct consequences regarding the design of the present CLIC BDS.

Plasmon resonant cavities in vertical nanowire arrays

Science.gov (United States)

Bora, Mihail; Bond, Tiziana C.; Fasenfest, Benjamin J.; Behymer, Elaine M.

2014-07-15

Tunable plasmon resonant cavity arrays in paired parallel nanowire waveguides are presented. Resonances can be observed when the waveguide length is an odd multiple of quarter plasmon wavelengths, consistent with boundary conditions of node and antinode at the ends. Two nanowire waveguides can satisfy the dispersion relation of a planar metal-dielectric-metal waveguide of equivalent width equal to the square field average weighted gap. Confinement factors of over 10.sup.3 are possible due to plasmon focusing in the inter-wire space.

A Study of Failure Modes in the ILC Main Linac

CERN Document Server

Eliasson, Peder; Krücker, Dirk; Latina, Andrea; Poirier, Freddy; Schulte, Daniel; Walker, Nicholas John; Xia, Guoxing

2006-01-01

Failures in the ILC can lead to beam loss or even damage the machine. In the paper quadrupole failures and errors in the klystron phase are being investigated and the impact on the machine protection is being considered for the main linac.

Polarimeters and energy spectrometers for the ILC beam delivery system

Energy Technology Data Exchange (ETDEWEB)

Boogert, S. [London Univ. (United Kingdom). Royal Holloway; Hildreth, M. [Univ. of Notre Dame (United States); Kaefer, K. [DESY, Hamburg (Germany); DESY, Zeuthen (DE)] (and others)

2009-02-15

This article gives an overview of current plans and issues for polarimeters and energy spectrometers in the Beam Delivery System of the ILC. It is meant to serve as a useful reference for the Detector Letter of Intent documents currently being prepared. (orig.)

A Study of Laser System Requirements for Application in Beam Diagnostics And Polarimetry at the ILC

Energy Technology Data Exchange (ETDEWEB)

Dixit, S.; Delerue, N.; Foster, B.; Howell, D.F.; Peach, K.; Quelch, G.; Qureshi, M.; Reichold, A.; /Oxford U.; Hirst, G.; Ross, I.; /Rutherford; Urakawa, J.; /KEK,; Soskov, V.; Variola, A.; Zomer, F.; /Orsay, LAL; Blair, G.A.; Boogert, S.T.; Boorman, G.; Bosco, A.; Driouichi, C.; Karataev, P.; /Royal Holloway, U. of London; Brachmann,; /SLAC

2007-02-12

Advanced laser systems will be essential for a range of diagnostics devices and polarimetry at the ILC. High average power, high beam quality, excellent stability and reliability will be crucial in order to deliver the information required to attain the necessary ILC luminosity as well as for efficient polarimetry. The key parameters are listed together with the R & D required to achieve the necessary laser system performance.

Simplified SUSY at the ILC

Energy Technology Data Exchange (ETDEWEB)

Berggren, Mikael

2013-08-15

At the ILC, one has the possibility to search for SUSY in an model-independent way: The corner-stone of SUSY is that sparticles couple as particles. This is independent of the mechanism responsible for SUSY breaking. Any model will have one Lightest SUSY Particle (LSP), and one Next to Lightest SUSY Particle (NLSP). In models with conserved R-parity, the NLSP must decay solely to the LSP and the SM partner of the NLSP. Therefore, studying NLSP production and decay can be regarded as a ''simplified model without simplification'': Any SUSY model will have such a process. The NLSP could be any sparticle: a slepton, an electroweak-ino, or even a squark. However, since there are only a finite number of sparticles, one can systematically search for signals of all possible NLSP:s. This way, the entire space of models that have a kinematically reachable NLSP can be covered. For any NLSP, the ''worst case'' can be determined, since the SUSY principle allows to calculate the cross-section once the NLSP nature and mass are given. The region in the LSP-NLSP mass-plane where the ''worst case'' could be discovered or excluded experimentally can be found by estimating background and efficiency at each point in the plane. From experience at LEP, it is expected that the lower signal-to background ratio will indeed be found for models with conserved R-parity. In this document, we show that at the ILC, such a program is possible, as it was at LEP. No loop-holes are left, even for difficult or non-standard cases: whatever the NLSP is it will be detectable.

Microbiota-Dependent Crosstalk Between Macrophages and ILC3 Promotes Intestinal Homeostasis

Science.gov (United States)

Mortha, Arthur; Chudnovskiy, Aleksey; Hashimoto, Daigo; Bogunovic, Milena; Spencer, Sean P.; Belkaid, Yasmine; Merad, Miriam

2014-01-01

The intestinal microbiota and tissue-resident myeloid cells promote immune responses that maintain intestinal homeostasis in the host. However, the cellular cues that translate microbial signals into intestinal homeostasis remain unclear. Here, we show that deficient granulocyte-macrophage colony-stimulating factor (GM-CSF) production altered mononuclear phagocyte effector functions and led to reduced regulatory T cell (Treg) numbers and impaired oral tolerance. We observed that RORγt+ innate lymphoid cells (ILCs) are the primary source of GM-CSF in the gut and that ILC-driven GM-CSF production was dependent on the ability of macrophages to sense microbial signals and produce interleukin-1β. Our findings reveal that commensal microbes promote a crosstalk between innate myeloid and lymphoid cells that leads to immune homeostasis in the intestine. PMID:24625929

Microbiota-dependent crosstalk between macrophages and ILC3 promotes intestinal homeostasis.

Science.gov (United States)

Mortha, Arthur; Chudnovskiy, Aleksey; Hashimoto, Daigo; Bogunovic, Milena; Spencer, Sean P; Belkaid, Yasmine; Merad, Miriam

2014-03-28

The intestinal microbiota and tissue-resident myeloid cells promote immune responses that maintain intestinal homeostasis in the host. However, the cellular cues that translate microbial signals into intestinal homeostasis remain unclear. Here, we show that deficient granulocyte-macrophage colony-stimulating factor (GM-CSF) production altered mononuclear phagocyte effector functions and led to reduced regulatory T cell (T(reg)) numbers and impaired oral tolerance. We observed that RORγt(+) innate lymphoid cells (ILCs) are the primary source of GM-CSF in the gut and that ILC-driven GM-CSF production was dependent on the ability of macrophages to sense microbial signals and produce interleukin-1β. Our findings reveal that commensal microbes promote a crosstalk between innate myeloid and lymphoid cells that leads to immune homeostasis in the intestine.

The RF Design of an HOM Polarized RF Gun for the ILC

International Nuclear Information System (INIS)

Wang, J.W.; Clendenin, J.E.; Colby, E.R.; Miller, R.A.; Lewellen, J.W.

2006-01-01

The ILC requires a polarized electron beam. While a highly polarized beam can be produced by a GaAs-type cathode in a DC gun of the type currently in use at SLAC, JLAB and elsewhere, the ILC injector system can be simplified and made more efficient if a GaAs-type cathode can be combined with a low emittance RF gun. Since this type of cathode is known to be extremely sensitive to vacuum contamination including back bombardment by electrons and ions, any successful polarized RF gun must have a significantly improved operating vacuum compared to existing RF guns. We present a new RF design for an L-Band normal conducting (NC) RF gun for the ILC polarized electron source. This design incorporates a higher order mode (HOM) structure, whose chief virtue in this application is an improved conductance for vacuum pumping on the cathode. Computer simulation models have been used to optimize the RF parameters with two principal goals: first to minimize the required RF power; second to reduce the peak surface field relative to the field at the cathode in order to suppress field emitted electron bombardment. The beam properties have been simulated initially using PARMELA. Vacuum and other practical issues for implementing this design are discussed

Report of the Fermilab ILC Citizens' Task Force

Energy Technology Data Exchange (ETDEWEB)

None

2008-06-01

Fermi National Accelerator Laboratory convened the ILC Citizens' Task Force to provide guidance and advice to the laboratory to ensure that community concerns and ideas are included in all public aspects of planning and design for a proposed future accelerator, the International Linear Collider. In this report, the members of the Task Force describe the process they used to gather and analyze information on all aspects of the proposed accelerator and its potential location at Fermilab in northern Illinois. They present the conclusions and recommendations they reached as a result of the learning process and their subsequent discussions and deliberations. While the Task Force was charged to provide guidance on the ILC, it became clear during the process that the high cost of the proposed accelerator made a near-term start for the project at Fermilab unlikely. Nevertheless, based on a year of extensive learning and dialogue, the Task Force developed a series of recommendations for Fermilab to consider as the laboratory develops all successor projects to the Tevatron. The Task Force recognizes that bringing a next-generation particle physics project to Fermilab will require both a large international effort and the support of the local community. While the Task Force developed its recommendations in response to the parameters of a future ILC, the principles they set forth apply directly to any large project that may be conceived at Fermilab, or at other laboratories, in the future. With this report, the Task Force fulfills its task of guiding Fermilab from the perspective of the local community on how to move forward with a large-scale project while building positive relationships with surrounding communities. The report summarizes the benefits, concerns and potential impacts of bringing a large-scale scientific project to northern Illinois.

TESLA superconducting RF cavity development

International Nuclear Information System (INIS)

Koepke, K.

1995-01-01

The TESLA collaboration has made steady progress since its first official meeting at Cornell in 1990. The infrastructure necessary to assemble and test superconducting rf cavities has been installed at the TESLA Test Facility (TTF) at DESY. 5-cell, 1.3 GHz cavities have been fabricated and have reached accelerating fields of 25 MV/m. Full sized 9-cell copper cavities of TESLA geometry have been measured to verify the higher order modes present and to evaluate HOM coupling designs. The design of the TESLA 9-cell cavity has been finalized and industry has started delivery. Two prototype 9-cell niobium cavities in their first tests have reached accelerating fields of 10 MV/m and 15 MV/m in a vertical dewar after high peak power (HPP) conditioning. The first 12 m TESLA cryomodule that will house 8 9-cell cavities is scheduled to be delivered in Spring 1995. A design report for the TTF is in progress. The TTF test linac is scheduled to be commissioned in 1996/1997. (orig.)

Polarization of ILC2s in Peripheral Blood Might Contribute to Immunosuppressive Microenvironment in Patients with Gastric Cancer

Directory of Open Access Journals (Sweden)

Qingli Bie

2014-01-01

Full Text Available Newly identified nuocytes or group 2 innate lymphoid cells (ILC2s play an important role in Th2 cell mediated immunity such as protective immune responses to helminth parasites, allergic asthma, and chronic rhinosinusitis. However, the contributions of ILC2s in the occurrence and development of cancer remain unknown. Our previous study found that there was a predominant Th2 phenotype in patients with gastric cancer. In this study, the ILC2s related genes or molecules in PBMC from patients with gastric cancer were measured, and the potential correlation between them was analyzed. The expression levels of RORα, GATA3, T1/ST2, IL-17RB, CRTH2, IL-33, IL-5, and IL-4 mRNA were significantly increased in patients, but no significant changes were found in ICOS, CD45, and IL-13 expression, and there was a positive correlation between RORα or IL-13 and other related factors, such as ICOS and CD45. The increased frequency of ILC2s was also found in PBMC of patients by flow cytometry. In addition, the mRNA of Arg1 and iNOS were also significantly increased in patients. These results suggested that there are polarized ILC2s in gastric cancer patients which might contribute to immunosuppressive microenvironment and closely related to the upregulation of MDSCs and M2 macrophages.

Proton irradiation effects in oxide-confined vertical cavity surface emitting laser (VCSEL) diodes

International Nuclear Information System (INIS)

Barnes, C.E.; Swift, G.M.; Guertin, S.; Schwank, J.R.; Armendariz, M.G.; Hash, G.L.; Choquette, K.D.

1999-01-01

Vertical cavity surface emitting laser (VCSEL) diodes are employed as the emitter portion of opto-couplers that are used in space applications. Proton irradiation studies on VCSELs were performed at the Indiana University cyclotron facility. The beam energy was set at 192 MeV, the beam current was 200 nA that is equivalent to a flux of approximately 1*10 11 protons/cm 2 .s. We conclude that the oxide confined VCSELs examined in this study show more than sufficient radiation hardness for nearly all space applications. The observed proton-induced decreases in light output and the corresponding increases in laser threshold current can be explained in terms of proton-induced displacement damage which introduces non-radiative recombination centers in the active region of the lasers and causes a decrease in laser efficiency. These radiation effects accentuate the detrimental thermal effects observed at high currents. We also note that forward bias annealing is effective in these devices in producing at least partial recovery of the light output, and that this may be a viable hardness assurance technique during a flight mission. (A.C.)

A UWOC system based on a 6 m/5.2 Gbps 680 nm vertical-cavity surface-emitting laser

Science.gov (United States)

Li, Chung-Yi; Tsai, Wen-Shing

2018-02-01

This study proves that an underwater wireless optical communication (UWOC) based on a 6 m/5.2 Gbps 68 nm vertical-cavity surface-emitting laser (VCSEL)-based system is superior to a 405 nm UWOC system. This UWOC application is the first to use a VCSEL at approximately 680 nm. The experiment also proved that a 680 nm VCSEL has the same transmission distance as that of an approximately 405 nm laser diode. The 680 nm VCSEL has a 5.2 Gbps high transmission rate and can transmit up to 6 m. Thus, the setup is the best alternative solution for high-speed UWOC applications.

Measuring Hadronic Jets at the ILC - From Particle Flow Calorimetry to the Higgs Self-Coupling

CERN Document Server

Hermberg, Benjamin

2015-01-01

This work deals with the development of a technical prototype of a highly segmented hadron calorimeter for precision measurements at the future International Linear Col- lider (ILC). The precision measurements at the ILC pose special challenges for both the detector technology as well as for the reconstruction methods. In this thesis two aspects to hadronic final states are examined. The first part deals with a prototype of a highly segmented hadronic calorimeter and the second part with kinematic Fits for the deter- mination of the Higgs self-coupling in decays of the Higgs boson into b quarks. The challenge for the examined prototype of the hadronic calorimeter is the demon- stration of the technical feasibility of a real detector. The ILC is pursuing the Particle Flow concept, as a consequence, it follows for the calorimeter a high granularity and an integrated readout electronics. Two important aspects of the calorimeter prototype are the channel-wise adjustable trigger threshold and the power-pulsing fun...

Transverse mode selection in vertical-cavity surface-emitting lasers via deep impurity-induced disordering

Science.gov (United States)

O'Brien, Thomas R.; Kesler, Benjamin; Dallesasse, John M.

2017-02-01

Top emission 850-nm vertical-cavity surface-emitting lasers (VCSELs) demonstrating transverse mode selection via impurity-induced disordering (IID) are presented. The IID apertures are fabricated via closed ampoule zinc diffusion. A simple 1-D plane wave model based on the intermixing of Group III atoms during IID is presented to optimize the mirror loss of higher-order modes as a function of IID strength and depth. In addition, the impact of impurity diffusion into the cap layer of the lasers is shown to improve contact resistance. Further investigation of the mode-dependent characteristics of the device imply an increase in the thermal impedance associated with the fraction of IID contained within the oxide aperture. The optimization of the ratio of the IID aperture to oxide aperture is experimentally determined. Single fundamental mode output of 1.6 mW with 30 dBm side mode suppression ratio is achieved by a 3.0 μm oxide-confined device with an IID aperture of 1.3 μm indicating an optimal IID aperture size of 43% of the oxide aperture.

Proceedings of the ILC Physics Working Group Meeting at KEK in the period from May 2007 to June 2009

CERN Document Server

AUTHOR|(CDS)2080137; Ono, Hiroaki; Kanemura, Shinya; Suehara, Taikan; Takubo, Yosuke; Tanabe, Tomohiko; Fujii, Keisuke

2010-01-01

The ILC physics working group is a mixture of experimentalists and theorists mainly working in Japan. It has its origin in the previous LC physics study group and has been reformed with the initiative of a JSPS Creative Scientific Research project: "Research and Development of a Novel Detector System for the International Linear Collider". The working group is, however, formally independent of the JSPS project and is open to everybody who is interested in ILC physics. The primary task of the working group is to reexamine the ILC physics in the context of the expected LHC outcome and to further strengthen the physics case for the ILC project. The topics covered in the working group activities range from key measurements such as those of the Higgs self-coupling and the top Yukawa coupling to uncover the secrets of the electroweak symmetry breaking to various new physics scenarios like supersymmetry, large extra dimensions, and other models of terascale physics. The working group has held ten General Meetings in...

Search for Higgs portal DM at the ILC

Energy Technology Data Exchange (ETDEWEB)

Ko, P. [School of Physics, KIAS,Seoul 02455 (Korea, Republic of); Quantum Universe Center, KIAS,Seoul 02455 (Korea, Republic of); Yokoya, Hiroshi [Quantum Universe Center, KIAS,Seoul 02455 (Korea, Republic of)

2016-08-18

Higgs portal dark matter (DM) models are simple interesting and viable DM models. There are three types of the models depending on the DM spin: scalar, fermion and vector DM models. In this paper, we consider renormalizable, unitary and gauge invariant Higgs portal DM models, and study how large parameter regions can be surveyed at the International Linear Collider (ILC) experiment at √s=500 GeV. For the Higgs portal singlet fermion and vector DM cases, the force mediator involves two scalar propagators, the SM-like Higgs boson and the dark Higgs boson. We show that their interference generates interesting and important patterns in the mono-Z plus missing E{sub T} signatures at the ILC, and the results are completely different from those obtained from the Higgs portal DM models within the effective field theories. In addition, we show that it would be possible to distinguish the spin of DM in the Higgs portal scenarios, if the shape of the recoil-mass distribution is observed. We emphasize that the interplay between these collider observations and those in the direct detection experiments has to be performed in the model with renomalizability and unitarity to combine the model analyses in different scales.

Characterization of 2.3 μm GaInAsSb-based vertical-cavity surface-emitting laser structures using photo-modulated reflectance

International Nuclear Information System (INIS)

Chai, G. M. T.; Hosea, T. J. C.; Fox, N. E.; Hild, K.; Ikyo, A. B.; Marko, I. P.; Sweeney, S. J.; Bachmann, A.; Arafin, S.; Amann, M.-C.

2014-01-01

We report angle dependent and temperature dependent (9 K–300 K) photo-modulated reflectance (PR) studies on vertical-cavity surface-emitting laser (VCSEL) structures, designed for 2.3 μm mid-infrared gas sensing applications. Changing the temperature allows us to tune the energies of the quantum well (QW) transitions relative to the VCSEL cavity mode (CM) energy. These studies show that this VCSEL structure has a QW-CM offset of 21 meV at room temperature. Consequently the QW ground-state transition comes into resonance with the CM at 220 ± 2 K. The results from these PR studies are closely compared with those obtained in a separate study of actual operating devices and show how the PR technique may be useful for device optimisation without the necessity of having first to process the wafers into working devices

Characterization of 2.3 μm GaInAsSb-based vertical-cavity surface-emitting laser structures using photo-modulated reflectance

Energy Technology Data Exchange (ETDEWEB)

Chai, G. M. T. [Ibnu Sina Institute for Fundamental Science Studies, Universiti Teknologi Malaysia, Johor Bahru 81310 (Malaysia); Hosea, T. J. C., E-mail: j.hosea@surrey.ac.uk [Ibnu Sina Institute for Fundamental Science Studies, Universiti Teknologi Malaysia, Johor Bahru 81310 (Malaysia); Advanced Technology Institute and Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Fox, N. E.; Hild, K.; Ikyo, A. B.; Marko, I. P.; Sweeney, S. J. [Advanced Technology Institute and Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Bachmann, A.; Arafin, S.; Amann, M.-C. [Walter Schottky Institut, Technische Universität Munchen, Am Coulombwall 4, D-85748 Garching (Germany)

2014-01-07

We report angle dependent and temperature dependent (9 K–300 K) photo-modulated reflectance (PR) studies on vertical-cavity surface-emitting laser (VCSEL) structures, designed for 2.3 μm mid-infrared gas sensing applications. Changing the temperature allows us to tune the energies of the quantum well (QW) transitions relative to the VCSEL cavity mode (CM) energy. These studies show that this VCSEL structure has a QW-CM offset of 21 meV at room temperature. Consequently the QW ground-state transition comes into resonance with the CM at 220 ± 2 K. The results from these PR studies are closely compared with those obtained in a separate study of actual operating devices and show how the PR technique may be useful for device optimisation without the necessity of having first to process the wafers into working devices.

Single-exposure two-dimensional superresolution in digital holography using a vertical cavity surface-emitting laser source array.

Science.gov (United States)

Granero, Luis; Zalevsky, Zeev; Micó, Vicente

2011-04-01

We present a new implementation capable of producing two-dimensional (2D) superresolution (SR) imaging in a single exposure by aperture synthesis in digital lensless Fourier holography when using angular multiplexing provided by a vertical cavity surface-emitting laser source array. The system performs the recording in a single CCD snapshot of a multiplexed hologram coming from the incoherent addition of multiple subholograms, where each contains information about a different 2D spatial frequency band of the object's spectrum. Thus, a set of nonoverlapping bandpass images of the input object can be recovered by Fourier transformation (FT) of the multiplexed hologram. The SR is obtained by coherent addition of the information contained in each bandpass image while generating an enlarged synthetic aperture. Experimental results demonstrate improvement in resolution and image quality.

The International Linear Collider Progress Report 2015

Energy Technology Data Exchange (ETDEWEB)

Yamamoto, Akira [SLAC National Accelerator Lab., Menlo Park, CA (United States)

2015-07-15

The ILC technical design is now being adapted to the preferred candidate site. Changes in layout are being managed by a rigorous change-control procedure. Series production of cavities for the European XFEL has shown that cavities can be mass-produced in industry with a performance well above XFEL requirements and close to that needed for the ILC. A number of technical developments are under way with a view to further reducing the ILC cost. This work must continue through the preparatory stage for ILC construction once resources become available. A summary of the design updates and of the further preparatory work needed is summarized in tabular form in the Appendix.

Comparison of nonpolar III-nitride vertical-cavity surface-emitting lasers with tunnel junction and ITO intracavity contacts

KAUST Repository

Leonard, J. T.

2016-03-01

We report on the lasing of III-nitride nonpolar, violet, vertical-cavity surface-emitting lasers (VCSELs) with III-nitride tunnel-junction (TJ) intracavity contacts and ion implanted apertures (IIAs). The TJ VCSELs are compared to similar VCSELs with tin-doped indium oxide (ITO) intracavity contacts. Prior to analyzing device results, we consider the relative advantages of III-nitride TJs for blue and green emitting VCSELs. The TJs are shown to be most advantageous for violet and UV VCSELs, operating near or above the absorption edge for ITO, as they significantly reduce the total internal loss in the cavity. However, for longer wavelength III-nitride VCSELs, TJs primarily offer the advantage of improved cavity design flexibility, allowing one to make the p-side thicker using a thick n-type III-nitride TJ intracavity contact. This offers improved lateral current spreading and lower loss, compare to using ITO and p-GaN, respectively. These aspects are particularly important for achieving high-power CW VCSELs, making TJs the ideal intracavity contact for any III-nitride VCSEL. A brief overview of III-nitride TJ growth methods is also given, highlighting the molecular-beam epitaxy (MBE) technique used here. Following this overview, we compare 12 mu m aperture diameter, violet emitting, TJ and ITO VCSEL experimental results, which demonstrate the significant improvement in differential efficiency and peak power resulting from the reduced loss in the TJ design. Specifically, the TJ VCSEL shows a peak power of similar to 550 mu W with a threshold current density of similar to 3.5 kA/cm(2), while the ITO VCSELs show peak powers of similar to 80 mu W and threshold current densities of similar to 7 kA/cm

Comparison of nonpolar III-nitride vertical-cavity surface-emitting lasers with tunnel junction and ITO intracavity contacts

KAUST Repository

Leonard, J. T.; Young, E. C.; Yonkee, B. P.; Cohen, D. A.; Shen, Chao; Margalith, T.; Ng, Tien Khee; Denbaars, S. P.; Ooi, Boon S.; Speck, J. S.; Nakamura, S.

2016-01-01

We report on the lasing of III-nitride nonpolar, violet, vertical-cavity surface-emitting lasers (VCSELs) with III-nitride tunnel-junction (TJ) intracavity contacts and ion implanted apertures (IIAs). The TJ VCSELs are compared to similar VCSELs with tin-doped indium oxide (ITO) intracavity contacts. Prior to analyzing device results, we consider the relative advantages of III-nitride TJs for blue and green emitting VCSELs. The TJs are shown to be most advantageous for violet and UV VCSELs, operating near or above the absorption edge for ITO, as they significantly reduce the total internal loss in the cavity. However, for longer wavelength III-nitride VCSELs, TJs primarily offer the advantage of improved cavity design flexibility, allowing one to make the p-side thicker using a thick n-type III-nitride TJ intracavity contact. This offers improved lateral current spreading and lower loss, compare to using ITO and p-GaN, respectively. These aspects are particularly important for achieving high-power CW VCSELs, making TJs the ideal intracavity contact for any III-nitride VCSEL. A brief overview of III-nitride TJ growth methods is also given, highlighting the molecular-beam epitaxy (MBE) technique used here. Following this overview, we compare 12 mu m aperture diameter, violet emitting, TJ and ITO VCSEL experimental results, which demonstrate the significant improvement in differential efficiency and peak power resulting from the reduced loss in the TJ design. Specifically, the TJ VCSEL shows a peak power of similar to 550 mu W with a threshold current density of similar to 3.5 kA/cm(2), while the ITO VCSELs show peak powers of similar to 80 mu W and threshold current densities of similar to 7 kA/cm

Modular PbSrS/PbS mid-infrared vertical external cavity surface emitting laser on Si

Science.gov (United States)

Khiar, A.; Rahim, M.; Fill, M.; Felder, F.; Zogg, H.; Cao, D.; Kobayashi, S.; Yokoyama, T.; Ishida, A.

2011-07-01

A mid-infrared vertical external cavity surface emitting laser (VECSEL) based on undoped PbS is described herein. A 200 nm-thick PbS active layer embedded between PbSrS cladding layers forms a double heterostructure. The layers are grown on a lattice and thermal expansion mismatched Si-substrate. The substrate is placed onto a flat bottom Bragg mirror again grown on a Si substrate, and the VECSEL is completed with a curved top mirror. Pumping is done optically with a 1.55 μm laser diode. This leads to an extremely simple modular fabrication process. Lasing wavelengths range from 3-3.8 μm at 100-260 K heat sink temperature. The lowest threshold power is ˜210 mWp and highest output power is ˜250 mWp. The influence of the different recombination mechanism as well as free carrier absorption on the threshold power is modeled.

Development of an advanced electropolishing setup for multicell high gradient niobium cavities

Directory of Open Access Journals (Sweden)

F. Éozénou

2012-08-01

Full Text Available Reproducible operation at high performances of superconducting cavities is required for linear accelerators. High beta elliptical cavities are thus of concern and, to achieve required performances for such resonators, surface preparation including electropolishing is recommended. We have designed and operate a setup for electropolishing in the vertical position of multicell cavities in order to: (i obtain high yield with large elliptical cavities for Superconducting Linac (SPL or European Spallation Source projects; (ii develop a reference installation demonstrating that this process is appropriate for the large scale treatment of cavities in industry. The setup described here is the first one able to electropolish vertically multicell cavities with circulating acid and high safety standards. This equipment makes it possible to use a wide range of parameters such as voltage, acid flow rate, temperature, and nitrogen injection with an R&D purpose in mind. Optimization is studied using modeling with COMSOL software for different cavities. As examples, we present some results for the 704 MHz high-beta SPL cavity and the 1300 MHz International Linear Collider cavity and show the influence of cathode shape on both acid flow and electric field distribution during the process. Importance of the size of the cavity and first results achieved on single-cell and nine-cell cavities will be discussed.

Mounting system for optical frequency reference cavities

Science.gov (United States)

Notcutt, Mark (Inventor); Hall, John L. (Inventor); Ma, Long-Sheng (Inventor)

2008-01-01

A technique for reducing the vibration sensitivity of laser-stabilizing optical reference cavities is based upon an improved design and mounting method for the cavity, wherein the cavity is mounted vertically. It is suspended at one plane, around the spacer cylinder, equidistant from the mirror ends of the cavity. The suspension element is a collar of an extremely low thermal expansion coefficient material, which surrounds the spacer cylinder and contacts it uniformly. Once the collar has been properly located, it is cemented in place so that the spacer cylinder is uniformly supported and does not have to be squeezed at all. The collar also includes a number of cavities partially bored into its lower flat surface, around the axial bore. These cavities are support points, into which mounting base pins will be inserted. Hence the collar is supported at a minimum of three points.

IL-4-producing ILC2s are required for the differentiation of TH2 cells following Heligmosomoides polygyrus infection

Science.gov (United States)

Pelly, VS; Kannan, Y; Coomes, SM; Entwistle, LJ; Rückerl, D; Seddon, B; MacDonald, AS; McKenzie, A; Wilson, MS

2017-01-01

Immunity to many human and murine gastrointestinal helminth parasites requires interleukin-4 (IL-4)-directed type 2 helper (TH2) differentiation of CD4+ T cells to elicit type-2 immunity. Despite a good understanding of the inflammatory cascade elicited following helminth infection, the initial source of IL-4 is unclear. Previous studies using the rat helminth parasite Nippostronglyus brasiliensis, identified an important role for basophil-derived IL-4 for TH2 differentiation. However, basophils are redundant for TH2 differentiation following infection with the natural helminth parasite of mice Heligmosomoides polygyrus, indicating that other sources of IL-4 are required. In this study using H. polygyrus, which is controlled by IL-4-dependent immunity, we identified that group-2 innate lymphoid cells (ILC2s) produced significant amounts of IL-4 and IL-2 following H. polygyrus infection. Leukotriene D4 was sufficient to stimulate IL-4 secretion by ILC2s, and the supernatant from activated ILC2s could potently drive TH2 differentiation in vitro in an IL-4-dependent manner. Furthermore, specific deletion of IL-4 from ILC2s compromised TH2 differentiation in vivo. Overall, this study highlights a previously unrecognized and important role for ILC2-derived IL-4 for TH2 differentiation in a natural TH2-dependent model of human helminthiasis. PMID:26883724

Development of monolithic pixel detector with SOI technology for the ILC vertex detector

Science.gov (United States)

Yamada, M.; Ono, S.; Tsuboyama, T.; Arai, Y.; Haba, J.; Ikegami, Y.; Kurachi, I.; Togawa, M.; Mori, T.; Aoyagi, W.; Endo, S.; Hara, K.; Honda, S.; Sekigawa, D.

2018-01-01

We have been developing a monolithic pixel sensor for the International Linear Collider (ILC) vertex detector with the 0.2 μm FD-SOI CMOS process by LAPIS Semiconductor Co., Ltd. We aim to achieve a 3 μm single-point resolution required for the ILC with a 20×20 μm2 pixel. Beam bunch crossing at the ILC occurs every 554 ns in 1-msec-long bunch trains with an interval of 200 ms. Each pixel must record the charge and time stamp of a hit to identify a collision bunch for event reconstruction. Necessary functions include the amplifier, comparator, shift register, analog memory and time stamp implementation in each pixel, and column ADC and Zero-suppression logic on the chip. We tested the first prototype sensor, SOFIST ver.1, with a 120 GeV proton beam at the Fermilab Test Beam Facility in January 2017. SOFIST ver.1 has a charge sensitive amplifier and two analog memories in each pixel, and an 8-bit Wilkinson-type ADC is implemented for each column on the chip. We measured the residual of the hit position to the reconstructed track. The standard deviation of the residual distribution fitted by a Gaussian is better than 3 μm.

Hadron production in photon-photon processes at the ILC

Energy Technology Data Exchange (ETDEWEB)

Sasikumar, Kollassery Swathi [Deutsches Elektronen-Synchrotron (DESY), Notkestrasse 85, 22607 Hamburg (Germany); Universitaet Hamburg, Institut fuer Experimentalphysik, Luruper Chaussee 149, 22761 Hamburg (Germany); Berggren, Carl Mikael; List, Jenny [Deutsches Elektronen-Synchrotron (DESY), Notkestrasse 85, 22607 Hamburg (Germany)

2016-07-01

The International linear Collider (ILC) is a proposed e{sup +}e{sup -} collider, designed to operate at energies from 91 GeV upto about 500 GeV (with the possibility to upgrade to 1 TeV). The highly clean conditions provided by the ILC enables us to make high precision measurements e.g. of the Higgs boson and to search for new particles. In addition to the desired e{sup +}e{sup -} collisions, parasitic collisions of real and virtual photons radiated off the e{sup ±} beams occur at rates of a few γγ collisions per bunch crossing. The γγ centre of mass energies reach from few 100 MeV up to the full e{sup +}e{sup -} centre of mass energy. For all these energies, in particular the production of hadrons,needs to be modelled correctly in order to estimate the impact of these backgrounds which pile-up on each e{sup +}e{sup -} event. This contribution discusses the current simulations of γγ → hadron processes, evaluates their impact on the detector and introduces new methods to remove them from the interesting physics events.

Deflecting cavity for beam diagnostics at Cornell ERL injector

International Nuclear Information System (INIS)

Belomestnykh, Sergey; Bazarov, Ivan; Shemelin, Valery; Sikora, John; Smolenski, Karl; Veshcherevich, Vadim

2010-01-01

A single-cell, 1300-MHz, TM110-like mode vertically deflecting cavity is designed and built for beam slice emittance measurements, and to study the temporal response of negative electron affinity photocathodes in the ERL injector at Cornell University. We describe the cavity shape optimization procedure, RF and mechanical design, its performance with beam.

Polarized γ source based on Compton backscattering in a laser cavity

Directory of Open Access Journals (Sweden)

V. Yakimenko

2006-09-01

Full Text Available We propose a novel gamma source suitable for generating a polarized positron beam for the next generation of electron-positron colliders, such as the International Linear Collider (ILC, and the Compact Linear Collider (CLIC. This 30-MeV polarized gamma source is based on Compton scattering inside a picosecond CO_{2} laser cavity generated from electron bunches produced by a 4-GeV linac. We identified and experimentally verified the optimum conditions for obtaining at least one gamma photon per electron. After multiplication at several consecutive interaction points, the circularly polarized gamma rays are stopped on a target, thereby creating copious numbers of polarized positrons. We address the practicality of having an intracavity Compton-polarized positron source as the injector for these new colliders.

GaN-based vertical-cavity surface-emitting lasers with tunnel junction contacts grown by metal-organic chemical vapor deposition

Science.gov (United States)

Lee, SeungGeun; Forman, Charles A.; Lee, Changmin; Kearns, Jared; Young, Erin C.; Leonard, John T.; Cohen, Daniel A.; Speck, James S.; Nakamura, Shuji; DenBaars, Steven P.

2018-06-01

We report the first demonstration of III–nitride vertical-cavity surface-emitting lasers (VCSELs) with tunnel junction (TJ) intracavity contacts grown completely by metal–organic chemical vapor deposition (MOCVD). For the TJs, n++-GaN was grown on in-situ activated p++-GaN after buffered HF surface treatment. The electrical properties and epitaxial morphologies of the TJs were first investigated on TJ LED test samples. A VCSEL with a TJ intracavity contact showed a lasing wavelength of 408 nm, a threshold current of ∼15 mA (10 kA/cm2), a threshold voltage of 7.8 V, a maximum output power of 319 µW, and a differential efficiency of 0.28%.

1.3 μm wavelength vertical cavity surface emitting laser fabricated by orientation-mismatched wafer bonding: A prospect for polarization control

Science.gov (United States)

Okuno, Yae L.; Geske, Jon; Gan, Kian-Giap; Chiu, Yi-Jen; DenBaars, Steven P.; Bowers, John E.

2003-04-01

We propose and demonstrate a long-wavelength vertical cavity surface emitting laser (VCSEL) which consists of a (311)B InP-based active region and (100) GaAs-based distributed Bragg reflectors (DBRs), with an aim to control the in-plane polarization of output power. Crystal growth on (311)B InP substrates was performed under low-migration conditions to achieve good crystalline quality. The VCSEL was fabricated by wafer bonding, which enables us to combine different materials regardless of their lattice and orientation mismatch without degrading their quality. The VCSEL was polarized with a power extinction ratio of 31 dB.

Hybrid III-V/SOI resonant cavity enhanced photodetector

DEFF Research Database (Denmark)

Learkthanakhachon, Supannee; Taghizadeh, Alireza; Park, Gyeong Cheol

2016-01-01

A hybrid III–V/SOI resonant-cavity-enhanced photodetector (RCE-PD) structure comprising a high-contrast grating (HCG) reflector, a hybrid grating (HG) reflector, and an air cavity between them, has been proposed and investigated. In the proposed structure, a light absorbing material is integrated...... as part of the HG reflector, enabling a very compact vertical cavity. Numerical investigations show that a quantum efficiency close to 100 % and a detection linewidth of about 1 nm can be achieved, which are desirable for wavelength division multiplexing applications. Based on these results, a hybrid RCE...

Studies on GEM modules for a Large Prototype TPC for the ILC

International Nuclear Information System (INIS)

Tsionou, Dimitra

2017-01-01

The International Linear Collider (ILC) is a future electron–positron collider with centre of mass energy of 500–1000 GeV. The International Large Detector (ILD) is one of two detector concepts at the ILC. Its high precision tracking system consists of Silicon sub-detectors and a Time Projection Chamber (TPC) equipped with micro-pattern gas detectors (MPGDs). Within the framework of the LCTPC collaboration, a Large Prototype (LP) TPC has been built as a demonstrator. This prototype has been equipped with Gas Electron Multiplier (GEM) modules and studied with electron beams of energies 1–6 GeV at the DESY test beam facility. The performance of the prototype detector and the extrapolation to the ILD TPC is presented here. In addition, ongoing optimisation studies and R&D activities in order to prepare the next GEM module iteration are discussed.

Studies on GEM modules for a Large Prototype TPC for the ILC

Energy Technology Data Exchange (ETDEWEB)

Tsionou, Dimitra, E-mail: dimitra.tsionou@desy.de

2017-02-11

The International Linear Collider (ILC) is a future electron–positron collider with centre of mass energy of 500–1000 GeV. The International Large Detector (ILD) is one of two detector concepts at the ILC. Its high precision tracking system consists of Silicon sub-detectors and a Time Projection Chamber (TPC) equipped with micro-pattern gas detectors (MPGDs). Within the framework of the LCTPC collaboration, a Large Prototype (LP) TPC has been built as a demonstrator. This prototype has been equipped with Gas Electron Multiplier (GEM) modules and studied with electron beams of energies 1–6 GeV at the DESY test beam facility. The performance of the prototype detector and the extrapolation to the ILD TPC is presented here. In addition, ongoing optimisation studies and R&D activities in order to prepare the next GEM module iteration are discussed.

Studies on GEM modules for a large prototype TPC for the ILC

International Nuclear Information System (INIS)

Tsionou, Dimitra

2016-12-01

The International Linear Collider (ILC) is a future electron-positron collider with centre of mass energy of 500-1000 GeV. The International Large Detector (ILD) is one of two detector concepts at the ILC. Its high precision tracking system consists of Silicon sub-detectors and a Time Projection Chamber (TPC) equipped with micro-pattern gas detectors (MPGDs). Within the framework of the LCTPC collaboration, a Large Prototype (LP) TPC has been built as a demonstrator. This prototype has been equipped with Gas Electron Multiplier (GEM) modules and studied with electron beams of energies 1-6 GeV at the DESY test beam facility. The performance of the prototype detector and the extrapolation to the ILD TPC is presented here. In addition, ongoing optimisation studies and R and D; activities in order to prepare the next GEM module iteration are discussed.

Compressibility effects in the shear layer over a rectangular cavity

Energy Technology Data Exchange (ETDEWEB)

Beresh, Steven J.; Wagner, Justin; Casper, Katya Marie

2016-10-26

we studied the influence of compressibility on the shear layer over a rectangular cavity of variable width in a free stream Mach number range of 0.6–2.5 using particle image velocimetry data in the streamwise centre plane. As the Mach number increases, the vertical component of the turbulence intensity diminishes modestly in the widest cavity, but the two narrower cavities show a more substantial drop in all three components as well as the turbulent shear stress. Furthermore, this contrasts with canonical free shear layers, which show significant reductions in only the vertical component and the turbulent shear stress due to compressibility. The vorticity thickness of the cavity shear layer grows rapidly as it initially develops, then transitions to a slower growth rate once its instability saturates. When normalized by their estimated incompressible values, the growth rates prior to saturation display the classic compressibility effect of suppression as the convective Mach number rises, in excellent agreement with comparable free shear layer data. The specific trend of the reduction in growth rate due to compressibility is modified by the cavity width.

Chaos synchronization in vertical-cavity surface-emitting laser based on rotated polarization-preserved optical feedback.

Science.gov (United States)

Nazhan, Salam; Ghassemlooy, Zabih; Busawon, Krishna

2016-01-01

In this paper, the influence of the rotating polarization-preserved optical feedback on the chaos synchronization of a vertical-cavity surface-emitting laser (VCSEL) is investigated experimentally. Two VCSELs' polarization modes (XP) and (YP) are gradually rotated and re-injected back into the VCSEL. The anti-phase dynamics synchronization of the two polarization modes is evaluated using the cross-correlation function. For a fixed optical feedback, a clear relationship is found between the cross-correlation coefficient and the polarization angle θp. It is shown that high-quality anti-phase polarization-resolved chaos synchronization is achieved at higher values of θp. The maximum value of the cross-correlation coefficient achieved is -0.99 with a zero time delay over a wide range of θp beyond 65° with a poor synchronization dynamic at θp less than 65°. Furthermore, it is observed that the antiphase irregular oscillation of the XP and YP modes changes with θp. VCSEL under the rotating polarization optical feedback can be a good candidate as a chaotic synchronization source for a secure communication system.

Transverse and polarization effects in index-guided vertical-cavity surface-emitting lasers

International Nuclear Information System (INIS)

Torre, M. S.; Masoller, C.; Mandel, Paul

2006-01-01

We study numerically the polarization dynamics of vertical-cavity surface-emitting lasers (VCSEL's) operating in the fundamental transverse mode. We use an extension of the spin-flip model that not only accounts for the vector nature of the laser field, but also considers spatial transverse effects. The model assumes two orthogonal, linearly polarized fields, which are coupled to two carrier populations, associated with different spin sublevels of the conduction and valence bands in the quantum-well active region. Spatial effects are taken into account by considering transverse profiles for the two polarizations, for the two carrier populations, and for the carrier diffusion. The optical profile is the LP 01 mode, suitable for describing index-guided VCSEL's with cylindrical symmetry emitting on the fundamental transverse mode for both polarizations. We find that in small-active-region VCSEL's, fast carrier diffusion induces self-sustained oscillations of the total laser output, which are not present in larger-area devices or with slow carrier diffusion. These self-pulsations appear close to threshold, and, as the injection current increases, they grow in amplitude; however, there is saturation and the self-pulsations disappear at higher injection levels. The dependence of the oscillation amplitude on various laser parameters is investigated, and the results are found to be in good qualitative agreement with those reported by Van der Sande et al. [Opt. Lett. 29, 53 (2004)], based on a rate-equation model that takes into account transverse inhomogeneities through an intensity-dependent confinement factor

Resource-efficient ILC for LTI/LTV systems through LQ tracking and stable inversion: enabling large feedforward tasks on a position-dependent printer

NARCIS (Netherlands)

van Zundert, J.; Bolder, J.J.; Koekebakker, S.H.; Oomen, T.A.E.

Iterative learning control (ILC) enables high performance for systems that execute repeating tasks. Norm-optimal ILC based on lifted system representations provides an analytic expression for the optimal feedforward signal. However, for large tasks the computational load increases rapidly for

ilc-25.pdf | dec2005 | jess | Indian Academy of Sciences

Indian Academy of Sciences (India)

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International Linear Collider Reference Design Report Volume 2: PHYSICS AT THE ILC

CERN Document Server

Djouadi, Abdelhak; Moenig, Klaus; Okada, Yasuhiro; Oreglia, Mark; Yamashita, Satoru; Aarons, Gerald; Abe, Toshinori; Abernathy, Jason; Ablikim, Medina; Abramowicz, Halina; Adey, David; Adloff, Catherine; Adolphsen, Chris; Afanaciev, Konstantin; Agapov, Ilya; Ahn, Jung-Keun; Aihara, Hiroaki; Akemoto, Mitsuo; del Carmen Alabau, Maria; Albert, Justin; Albrecht, Hartwig; Albrecht, Michael; Alesini, David; Alexander, Gideon; Alexander, Jim; Allison, Wade; Amann, John; Amirikas, Ramila; An, Qi; Anami, Shozo; Ananthanarayan, B.; Anderson, Terry; Andricek, Ladislav; Anduze, Marc; Anerella, Michael; Anfimov, Nikolai; Angal-Kalinin, Deepa; Antipov, Sergei; Antoine, Claire; Aoki, Mayumi; Aoza, Atsushi; Aplin, Steve; Appleby, Rob; Arai, Yasuo; Araki, Sakae; Arkan, Tug; Arnold, Ned; Arnold, Ray; Arnowitt, Richard; Artru, Xavier; Arya, Kunal; Aryshev, Alexander; Asakawa, Eri; Asiri, Fred; Asner, David; Atac, Muzaffer; Atoian, Grigor; Attié, David; Augustin, Jean-Eudes; Augustine, David B.; Ayres, Bradley; Aziz, Tariq; Baars, Derek; Badaud, Frederique; Baddams, Nigel; Bagger, Jonathan; Bai, Sha; Bailey, David; Bailey, Ian R.; Baker, David; Balalykin, Nikolai I.; Balbuena, Juan Pablo; Baldy, Jean-Luc; Ball, Markus; Ball, Maurice; Ballestrero, Alessandro; Ballin, Jamie; Baltay, Charles; Bambade, Philip; Ban, Syuichi; Band, Henry; Bane, Karl; Banerjee, Bakul; Barbanotti, Serena; Barbareschi, Daniele; Barbaro-Galtieri, Angela; Barber, Desmond P.; Barbi, Mauricio; Bardin, Dmitri Y.; Barish, Barry; Barklow, Timothy L.; Barlow, Roger; Barnes, Virgil E.; Barone, Maura; Bartels, Christoph; Bartsch, Valeria; Basu, Rahul; Battaglia, Marco; Batygin, Yuri; Baudot, Jerome; Baur, Ulrich; Elwyn Baynham, D.; Beard, Carl; Bebek, Chris; Bechtle, Philip; Becker, Ulrich J.; Bedeschi, Franco; Bedjidian, Marc; Behera, Prafulla; Behnke, Ties; Bellantoni, Leo; Bellerive, Alain; Bellomo, Paul; Bentson, Lynn D.; Benyamna, Mustapha; Bergauer, Thomas; Berger, Edmond; Bergholz, Matthias; Beri, Suman; Berndt, Martin; Bernreuther, Werner; Bertolini, Alessandro; Besancon, Marc; Besson, Auguste; Beteille, Andre; Bettoni, Simona; Beyer, Michael; Bhandari, R.K.; Bharadwaj, Vinod; Bhatnagar, Vipin; Bhattacharya, Satyaki; Bhattacharyya, Gautam; Bhattacherjee, Biplob; Bhuyan, Ruchika; Bi, Xiao-Jun; Biagini, Marica; Bialowons, Wilhelm; Biebel, Otmar; Bieler, Thomas; Bierwagen, John; Birch, Alison; Bisset, Mike; Biswal, S.S.; Blackmore, Victoria; Blair, Grahame; Blanchard, Guillaume; Blazey, Gerald; Blue, Andrew; Blümlein, Johannes; Boffo, Christian; Bohn, Courtlandt; Boiko, V.I.; Boisvert, Veronique; Bondarchuk, Eduard N.; Boni, Roberto; Bonvicini, Giovanni; Boogert, Stewart; Boonekamp, Maarten; Boorman, Gary; Borras, Kerstin; Bortoletto, Daniela; Bosco, Alessio; Bosio, Carlo; Bosland, Pierre; Bosotti, Angelo; Boudry, Vincent; Boumediene, Djamel-Eddine; Bouquet, Bernard; Bourov, Serguei; Bowden, Gordon; Bower, Gary; Boyarski, Adam; Bozovic-Jelisavcic, Ivanka; Bozzi, Concezio; Brachmann, Axel; Bradshaw, Tom W.; Brandt, Andrew; Brasser, Hans Peter; Brau, Benjamin; Brau, James E.; Breidenbach, Martin; Bricker, Steve; Brient, Jean-Claude; Brock, Ian; Brodsky, Stanley; Brooksby, Craig; Broome, Timothy A.; Brown, David; Brown, David; Brownell, James H.; Bruchon, Mélanie; Brueck, Heiner; Brummitt, Amanda J.; Brun, Nicole; Buchholz, Peter; Budagov, Yulian A.; Bulgheroni, Antonio; Bulyak, Eugene; Bungau, Adriana; Bürger, Jochen; Burke, Dan; Burkhart, Craig; Burrows, Philip; Burt, Graeme; Burton, David; Büsser, Karsten; Butler, John; Butterworth, Jonathan; Buzulutskov, Alexei; Cabruja, Enric; Caccia, Massimo; Cai, Yunhai; Calcaterra, Alessandro; Caliier, Stephane; Camporesi, Tiziano; Cao, Jun-Jie; Cao, J.S.; Capatina, Ofelia; Cappellini, Chiara; Carcagno, Ruben; Carena, Marcela; Carloganu, Cristina; Carosi, Roberto; Stephen Carr, F.; Carrion, Francisco; Carter, Harry F.; Carter, John; Carwardine, John; Cassel, Richard; Cassell, Ronald; Cavallari, Giorgio; Cavallo, Emanuela; Cembranos, Jose A.R.; Chakraborty, Dhiman; Chandez, Frederic; Charles, Matthew; Chase, Brian; Chattopadhyay, Subhasis; Chauveau, Jacques; Chefdeville, Maximilien; Chehab, Robert; Chel, Stéphane; Chelkov, Georgy; Chen, Chiping; Chen, He Sheng; Chen, Huai Bi; Chen, Jia Er; Chen, Sen Yu; Chen, Shaomin; Chen, Shenjian; Chen, Xun; Chen, Yuan Bo; Cheng, Jian; Chevallier, M.; Chi, Yun Long; Chickering, William; Cho, Gi-Chol; Cho, Moo-Hyun; Choi, Jin-Hyuk; Choi, Jong Bum; Choi, Seong Youl; Choi, Young-Il; Choudhary, Brajesh; Choudhury, Debajyoti; Rai Choudhury, S.; Christian, David; Christian, Glenn; Christophe, Grojean; Chung, Jin-Hyuk; Church, Mike; Ciborowski, Jacek; Cihangir, Selcuk; Ciovati, Gianluigi; Clarke, Christine; Clarke, Don G.; Clarke, James A.; Clements, Elizabeth; Coca, Cornelia; Coe, Paul; Cogan, John; Colas, Paul; Collard, Caroline; Colledani, Claude; Combaret, Christophe; Comerma, Albert; Compton, Chris; Constance, Ben; Conway, John; Cook, Ed; Cooke, Peter; Cooper, William; Corcoran, Sean; Cornat, Rémi; Corner, Laura; Cortina Gil, Eduardo; Clay Corvin, W.; Cotta Ramusino, Angelo; Cowan, Ray; Crawford, Curtis; Cremaldi, Lucien M; Crittenden, James A.; Cussans, David; Cvach, Jaroslav; da Silva, Wilfrid; Dabiri Khah, Hamid; Dabrowski, Anne; Dabrowski, Wladyslaw; Dadoun, Olivier; Dai, Jian Ping; Dainton, John; Daly, Colin; Damerell, Chris; Danilov, Mikhail; Daniluk, Witold; Daram, Sarojini; Datta, Anindya; Dauncey, Paul; David, Jacques; Davier, Michel; Davies, Ken P.; Dawson, Sally; De Boer, Wim; De Curtis, Stefania; De Groot, Nicolo; de la Taille, Christophe; de Lira, Antonio; De Roeck, Albert; de Sangro, Riccardo; De Santis,Stefano; Deacon, Laurence; Deandrea, Aldo; Dehmelt, Klaus; Delagnes, Eric; Delahaye, Jean-Pierre; Delebecque, Pierre; Delerue, Nicholas; Delferriere, Olivier; Demarteau, Marcel; Deng, Zhi; Denisov, Yu.N.; Densham, Christopher J.; Desch, Klaus; Deshpande, Nilendra; Devanz, Guillaume; Devetak, Erik; Dexter, Amos; Di benedetto, Vito; Diéguez, Angel; Diener, Ralf; Dinh, Nguyen Dinh; Dixit, Madhu; Dixit, Sudhir; Dolezal, Zdenek; Dollan, Ralph; Dong, Dong; Dong, Hai Yi; Dorfan, Jonathan; Dorokhov, Andrei; Doucas, George; Downing, Robert; Doyle, Eric; Doziere, Guy; Drago, Alessandro; Dragt, Alex; Drake, Gary; Drásal, Zbynek; Dreiner, Herbert; Drell, Persis; Driouichi, Chafik; Drozhdin, Alexandr; Drugakov, Vladimir; Du, Shuxian; Dugan, Gerald; Duginov, Viktor; Dulinski, Wojciech; Dulucq, Frederic; Dutta, Sukanta; Dwivedi, Jishnu; Dychkant, Alexandre; Dzahini, Daniel; Eckerlin, Guenter; Edwards, Helen; Ehrenfeld, Wolfgang; Ehrlichman, Michael; Ehrlichmann, Heiko; Eigen, Gerald; Elagin, Andrey; Elementi, Luciano; Eliasson, Peder; Ellis, John; Ellwood, George; Elsen, Eckhard; Emery, Louis; Enami, Kazuhiro; Endo, Kuninori; Enomoto, Atsushi; Eozénou, Fabien; Erbacher, Robin; Erickson, Roger; Oleg Eyser, K.; Fadeyev, Vitaliy; Fang, Shou Xian; Fant, Karen; Fasso, Alberto; Faucci Giannelli, Michele; Fehlberg, John; Feld, Lutz; Feng, Jonathan L.; Ferguson, John; Fernandez-Garcia, Marcos; Luis Fernandez-Hernando, J.; Fiala, Pavel; Fieguth, Ted; Finch, Alexander; Finocchiaro, Giuseppe; Fischer, Peter; Fisher, Peter; Eugene Fisk, H.; Fitton, Mike D.; Fleck, Ivor; Fleischer, Manfred; Fleury, Julien; Flood, Kevin; Foley, Mike; Ford, Richard; Fortin, Dominique; Foster, Brian; Fourches, Nicolas; Francis, Kurt; Frey, Ariane; Frey, Raymond; Friedsam, Horst; Frisch, Josef; Frishman, Anatoli; Fuerst, Joel; Fujii, Keisuke; Fujimoto, Junpei; Fukuda, Masafumi; Fukuda, Shigeki; Funahashi, Yoshisato; Funk, Warren; Furletova, Julia; Furukawa, Kazuro; Furuta, Fumio; Fusayasu, Takahiro; Fuster, Juan; Gadow, Karsten; Gaede, Frank; Gaglione, Renaud; Gai, Wei; Gajewski, Jan; Galik, Richard; Galkin, Alexei; Galkin, Valery; Gallin-Martel, Laurent; Gannaway, Fred; Gao, Jian She; Gao, Jie; Gao, Yuanning; Garbincius, Peter; Garcia-Tabares, Luis; Garren, Lynn; Garrido, Luís; Garutti, Erika; Garvey, Terry; Garwin, Edward; Gascón, David; Gastal, Martin; Gatto, Corrado; Gatto, Raoul; Gay, Pascal; Ge, Lixin; Ge, Ming Qi; Ge, Rui; Geiser, Achim; Gellrich, Andreas; Genat, Jean-Francois; Geng, Zhe Qiao; Gentile, Simonetta; Gerbick, Scot; Gerig, Rod; Ghosh, Dilip Kumar; Ghosh, Kirtiman; Gibbons, Lawrence; Giganon, Arnaud; Gillespie, Allan; Gillman, Tony; Ginzburg, Ilya; Giomataris, Ioannis; Giunta, Michele; Gladkikh, Peter; Gluza, Janusz; Godbole, Rohini; Godfrey, Stephen; Goldhaber, Gerson; Goldstein, Joel; Gollin, George D.; Gonzalez-Sanchez, Francisco Javier; Goodrick, Maurice; Gornushkin, Yuri; Gostkin, Mikhail; Gottschalk, Erik; Goudket, Philippe; Gough Eschrich, Ivo; Gournaris, Filimon; Graciani, Ricardo; Graf, Norman; Grah, Christian; Grancagnolo, Francesco; Grandjean, Damien; Grannis, Paul; Grassellino, Anna; Graugés, Eugeni; Gray, Stephen; Green, Michael; Greenhalgh, Justin; Greenshaw, Timothy; Grefe, Christian; Gregor, Ingrid-Maria; Grenier, Gerald; Grimes, Mark; Grimm, Terry; Gris, Philippe; Grivaz, Jean-Francois; Groll, Marius; Gronberg, Jeffrey; Grondin, Denis; Groom, Donald; Gross, Eilam; Grunewald, Martin; Grupen, Claus; Grzelak, Grzegorz; Gu, Jun; Gu, Yun-Ting; Guchait, Monoranjan; Guiducci, Susanna; Guler, Ali Murat; Guler, Hayg; Gulmez, Erhan; Gunion, John; Guo, Zhi Yu; Gurtu, Atul; Ha, Huy Bang; Haas, Tobias; Haase, Andy; Haba, Naoyuki; Haber, Howard; Haensel, Stephan; Hagge, Lars; Hagura, Hiroyuki; Hajdu, Csaba; Haller, Gunther; Haller, Johannes; Hallermann, Lea; Halyo, Valerie; Hamaguchi, Koichi; Hammond, Larry; Han, Liang; Han, Tao; Hand, Louis; Handu, Virender K.; Hano, Hitoshi; Hansen, Christian; Hansen, Jørn Dines; Hansen, Jorgen Beck; Hara, Kazufumi; Harder, Kristian; Hartin, Anthony; Hartung, Walter; Hast, Carsten; Hauptman, John; Hauschild, Michael; Hauviller, Claude; Havranek, Miroslav; Hawkes, Chris; Hawkings, Richard; Hayano, Hitoshi; Hazumi, Masashi; He, An; He, Hong Jian; Hearty, Christopher; Heath, Helen; Hebbeker, Thomas; Hedberg, Vincent; Hedin, David; Heifets, Samuel; Heinemeyer, Sven; Heini, Sebastien; Helebrant, Christian; Helms, Richard; Heltsley, Brian; Henrot-Versille, Sophie; Henschel, Hans; Hensel, Carsten; Hermel, Richard; Herms, Atilà; Herten, Gregor; Hesselbach, Stefan; Heuer, Rolf-Dieter; Heusch, Clemens A.; Hewett, Joanne; Higashi, Norio; Higashi, Takatoshi; Higashi, Yasuo; Higo, Toshiyasu; Hildreth, Michael D.; Hiller, Karlheinz; Hillert, Sonja; Hillier, Stephen James; Himel, Thomas; Himmi, Abdelkader; Hinchliffe, Ian; Hioki, Zenro; Hirano, Koichiro; Hirose, Tachishige; Hisamatsu, Hiromi; Hisano, Junji; Hlaing, Chit Thu; Hock, Kai Meng; Hoeferkamp, Martin; Hohlfeld, Mark; Honda, Yousuke; Hong, Juho; Hong, Tae Min; Honma, Hiroyuki; Horii, Yasuyuki; Horvath, Dezso; Hosoyama, Kenji; Hostachy, Jean-Yves; Hou, Mi; Hou, Wei-Shu; Howell, David; Hronek, Maxine; Hsiung, Yee B.; Hu, Bo; Hu, Tao; Huang, Jung-Yun; Huang, Tong Ming; Huang, Wen Hui; Huedem, Emil; Huggard, Peter; Hugonie, Cyril; Hu-Guo, Christine; Huitu, Katri; Hwang, Youngseok; Idzik, Marek; Ignatenko, Alexandr; Ignatov, Fedor; Ikeda, Hirokazu; Ikematsu, Katsumasa; Ilicheva, Tatiana; Imbault, Didier; Imhof, Andreas; Incagli, Marco; Ingbir, Ronen; Inoue, Hitoshi; Inoue, Youichi; Introzzi, Gianluca; Ioakeimidi, Katerina; Ishihara, Satoshi; Ishikawa, Akimasa; Ishikawa, Tadashi; Issakov, Vladimir; Ito, Kazutoshi; Ivanov, V.V.; Ivanov, Valentin; Ivanyushenkov, Yury; Iwasaki, Masako; Iwashita, Yoshihisa; Jackson, David; Jackson, Frank; Jacobsen, Bob; Jaganathan, Ramaswamy; Jamison, Steven; Janssen, Matthias Enno; Jaramillo-Echeverria, Richard; Jaros, John; Jauffret, Clement; Jawale, Suresh B.; Jeans, Daniel; Jedziniak, Ron; Jeffery, Ben; Jehanno, Didier; Jenner, Leo J.; Jensen, Chris; Jensen, David R.; Jiang, Hairong; Jiang, Xiao Ming; Jimbo, Masato; Jin, Shan; Keith Jobe, R.; Johnson, Anthony; Johnson, Erik; Johnson, Matt; Johnston, Michael; Joireman, Paul; Jokic, Stevan; Jones, James; Jones, Roger M.; Jongewaard, Erik; Jönsson, Leif; Joshi, Gopal; Joshi, Satish C.; Jung, Jin-Young; Junk, Thomas; Juste, Aurelio; Kado, Marumi; Kadyk, John; Käfer, Daniela; Kako, Eiji; Kalavase, Puneeth; Kalinin, Alexander; Kalinowski, Jan; Kamitani, Takuya; Kamiya, Yoshio; Kamiya, Yukihide; Kamoshita, Jun-ichi; Kananov, Sergey; Kanaya, Kazuyuki; Kanazawa, Ken-ichi; Kanemura, Shinya; Kang, Heung-Sik; Kang, Wen; Kanjial, D.; Kapusta, Frédéric; Karataev, Pavel; Karchin, Paul E.; Karlen, Dean; Karyotakis, Yannis; Kashikhin, Vladimir; Kashiwagi, Shigeru; Kasley, Paul; Katagiri, Hiroaki; Kato, Takashi; Kato, Yukihiro; Katzy, Judith; Kaukher, Alexander; Kaur, Manjit; Kawagoe, Kiyotomo; Kawamura, Hiroyuki; Kazakov, Sergei; Kekelidze, V.D.; Keller, Lewis; Kelley, Michael; Kelly, Marc; Kelly, Michael; Kennedy, Kurt; Kephart, Robert; Keung, Justin; Khainovski, Oleg; Khan, Sameen Ahmed; Khare, Prashant; Khovansky, Nikolai; Kiesling, Christian; Kikuchi, Mitsuo; Kilian, Wolfgang; Killenberg, Martin; Kim, Donghee; Kim, Eun San; Kim, Eun-Joo; Kim, Guinyun; Kim, Hongjoo; Kim, Hyoungsuk; Kim, Hyun-Chui; Kim, Jonghoon; Kim, Kwang-Je; Kim, Kyung Sook; Kim, Peter; Kim, Seunghwan; Kim, Shin-Hong; Kim, Sun Kee; Kim, Tae Jeong; Kim, Youngim; Kim, Young-Kee; Kimmitt, Maurice; Kirby, Robert; Kircher, François; Kisielewska, Danuta; Kittel, Olaf; Klanner, Robert; Klebaner, Arkadiy L.; Kleinwort, Claus; Klimkovich, Tatsiana; Klinkby, Esben; Kluth, Stefan; Knecht, Marc; Kneisel, Peter; Ko, In Soo; Ko, Kwok; Kobayashi, Makoto; Kobayashi, Nobuko; Kobel, Michael; Koch, Manuel; Kodys, Peter; Koetz, Uli; Kohrs, Robert; Kojima, Yuuji; Kolanoski, Hermann; Kolodziej, Karol; Kolomensky, Yury G.; Komamiya, Sachio; Kong, Xiang Cheng; Konigsberg, Jacobo; Korbel, Volker; Koscielniak, Shane; Kostromin, Sergey; Kowalewski, Robert; Kraml, Sabine; Krammer, Manfred; Krasnykh, Anatoly; Krautscheid, Thorsten; Krawczyk, Maria; James Krebs, H.; Krempetz, Kurt; Kribs, Graham; Krishnagopal, Srinivas; Kriske, Richard; Kronfeld, Andreas; Kroseberg, Jürgen; Kruchonak, Uladzimir; Kruecker, Dirk; Krüger, Hans; Krumpa, Nicholas A.; Krumshtein, Zinovii; Kuang, Yu Ping; Kubo, Kiyoshi; Kuchler, Vic; Kudoh, Noboru; Kulis, Szymon; Kumada, Masayuki; Kumar, Abhay; Kume, Tatsuya; Kundu, Anirban; Kurevlev, German; Kurihara, Yoshimasa; Kuriki, Masao; Kuroda, Shigeru; Kuroiwa, Hirotoshi; Kurokawa, Shin-ichi; Kusano, Tomonori; Kush, Pradeep K.; Kutschke, Robert; Kuznetsova, Ekaterina; Kvasnicka, Peter; Kwon, Youngjoon; Labarga, Luis; Lacasta, Carlos; Lackey, Sharon; Lackowski, Thomas W.; Lafaye, Remi; Lafferty, George; Lagorio, Eric; Laktineh, Imad; Lal, Shankar; Laloum, Maurice; Lam, Briant; Lancaster, Mark; Lander, Richard; Lange, Wolfgang; Langenfeld, Ulrich; Langeveld, Willem; Larbalestier, David; Larsen, Ray; Lastovicka, Tomas; Lastovicka-Medin, Gordana; Latina, Andrea; Latour, Emmanuel; Laurent, Lisa; Le, Ba Nam; Le, Duc Ninh; Le Diberder, Francois; Dû, Patrick Le; Lebbolo, Hervé; Lebrun, Paul; Lecoq, Jacques; Lee, Sung-Won; Lehner, Frank; Leibfritz, Jerry; Lenkszus, Frank; Lesiak, Tadeusz; Levy, Aharon; Lewandowski, Jim; Leyh, Greg; Li, Cheng; Li, Chong Sheng; Li, Chun Hua; Li, Da Zhang; Li, Gang; Li, Jin; Li, Shao Peng; Li, Wei Ming; Li, Weiguo; Li, Xiao Ping; Li, Xue-Qian; Li, Yuanjing; Li, Yulan; Li, Zenghai; Li, Zhong Quan; Liang, Jian Tao; Liao, Yi; Lilje, Lutz; Guilherme Lima, J.; Lintern, Andrew J.; Lipton, Ronald; List, Benno; List, Jenny; Liu, Chun; Liu, Jian Fei; Liu, Ke Xin; Liu, Li Qiang; Liu, Shao Zhen; Liu, Sheng Guang; Liu, Shubin; Liu, Wanming; Liu, Wei Bin; Liu, Ya Ping; Liu, Yu Dong; Lockyer, Nigel; Logan, Heather E.; Logatchev, Pavel V.; Lohmann, Wolfgang; Lohse, Thomas; Lola, Smaragda; Lopez-Virto, Amparo; Loveridge, Peter; Lozano, Manuel; Lu, Cai-Dian; Lu, Changguo; Lu, Gong-Lu; Lu, Wen Hui; Lubatti, Henry; Lucotte, Arnaud; Lundberg, Björn; Lundin, Tracy; Luo, Mingxing; Luong, Michel; Luth, Vera; Lutz, Benjamin; Lutz, Pierre; Lux, Thorsten; Luzniak, Pawel; Lyapin, Alexey; Lynch, Clare; Ma, Li; Ma, Lili; Ma, Qiang; Ma, Wen-Gan; Macfarlane, David; Maciel, Arthur; MacLeod, Allan; MacNair, David; Mader, Wolfgang; Magill, Stephen; Magnan, Anne-Marie; Maiheu, Bino; Maity, Manas; Majchrzak, Millicent; Majumder, Gobinda; Makarov, Roman; Makowski, Dariusz; Malaescu, Bogdan; Mallik, C.; Mallik, Usha; Malton, Stephen; Malyshev, Oleg B.; Malysheva, Larisa I.; Mammosser, John; Mamta; Mamuzic, Judita; Manen, Samuel; Manghisoni, Massimo; Manly, Steven; Marcellini, Fabio; Marcisovsky, Michal; Markiewicz, Thomas W.; Marks, Steve; Marone, Andrew; Marti, Felix; Martin, Jean-Pierre; Martin, Victoria; Martin-Chassard, Gisèle; Martinez, Manel; Martinez-Rivero, Celso; Martsch, Dennis; Martyn, Hans-Ulrich; Maruyama, Takashi; Masuzawa, Mika; Mathez, Hervé; Matsuda, Takeshi; Matsumoto, Hiroshi; Matsumoto, Shuji; Matsumoto, Toshihiro; Matsunaga, Hiroyuki; Mättig, Peter; Mattison, Thomas; Mavromanolakis, Georgios; Mawatari, Kentarou; Mazzacane, Anna; McBride, Patricia; McCormick, Douglas; McCormick, Jeremy; McDonald, Kirk T.; McGee, Mike; McIntosh, Peter; McKee, Bobby; McPherson, Robert A.; Meidlinger, Mandi; Meier, Karlheinz; Mele, Barbara; Meller, Bob; Melzer-Pellmann, Isabell-Alissandra; Mendez, Hector; Mercer, Adam; Merkin, Mikhail; Meshkov, I.N.; Messner, Robert; Metcalfe, Jessica; Meyer, Chris; Meyer, Hendrik; Meyer, Joachim; Meyer, Niels; Meyners, Norbert; Michelato, Paolo; Michizono, Shinichiro; Mihalcea, Daniel; Mihara, Satoshi; Mihara, Takanori; Mikami, Yoshinari; Mikhailichenko, Alexander A.; Milardi, Catia; Miller, David J.; Miller, Owen; Miller, Roger J.; Milstene, Caroline; Mimashi, Toshihiro; Minashvili, Irakli; Miquel, Ramon; Mishra, Shekhar; Mitaroff, Winfried; Mitchell, Chad; Miura, Takako; Miyamoto, Akiya; Miyata, Hitoshi; Mjörnmark, Ulf; Mnich, Joachim; Moffeit, Kenneth; Mokhov, Nikolai; Molloy, Stephen; Monaco, Laura; Monasterio, Paul R.; Montanari, Alessandro; Moon, Sung Ik; Moortgat-Pick, Gudrid A.; Mora de Freitas, Paulo; Morel, Federic; Moretti, Stefano; Morgunov, Vasily; Mori, Toshinori; Morin, Laurent; Morisseau, François; Morita, Yoshiyuki; Morita, Youhei; Morita, Yuichi; Morozov, Nikolai; Morozumi, Yuichi; Morse, William; Moser, Hans-Guenther; Moultaka, Gilbert; Mtingwa, Sekazi; Mudrinic, Mihajlo; Mueller, Alex; Mueller, Wolfgang; Muennich, Astrid; Muhlleitner, Milada Margarete; Mukherjee, Bhaskar; Mukhopadhyaya, Biswarup; Müller, Thomas; Munro, Morrison; Murayama, Hitoshi; Muto, Toshiya; Myneni, Ganapati Rao; Nabhiraj, P.Y.; Nagaitsev, Sergei; Nagamine, Tadashi; Nagano, Ai; Naito, Takashi; Nakai, Hirotaka; Nakajima, Hiromitsu; Nakamura, Isamu; Nakamura, Tomoya; Nakanishi, Tsutomu; Nakao, Katsumi; Nakao, Noriaki; Nakayoshi, Kazuo; Nam, Sang; Namito, Yoshihito; Namkung, Won; Nantista, Chris; Napoly, Olivier; Narain, Meenakshi; Naroska, Beate; Nauenberg, Uriel; Nayyar, Ruchika; Neal, Homer; Nelson, Charles; Nelson, Janice; Nelson, Timothy; Nemecek, Stanislav; Neubauer, Michael; Neuffer, David; Newman, Myriam Q.; Nezhevenko, Oleg; Ng, Cho-Kuen; Nguyen, Anh Ky; Nguyen, Minh; Van Nguyen Thi,Hong; Niebuhr, Carsten; Niehoff, Jim; Niezurawski, Piotr; Nishitani, Tomohiro; Nitoh, Osamu; Noguchi, Shuichi; Nomerotski, Andrei; Noonan, John; Norbeck, Edward; Nosochkov, Yuri; Notz, Dieter; Nowak, Grazyna; Nowak, Hannelies; Noy, Matthew; Nozaki, Mitsuaki; Nyffeler, Andreas; Nygren, David; Oddone, Piermaria; O'Dell, Joseph; Oh, Jong-Seok; Oh, Sun Kun; Ohkuma, Kazumasa; Ohlerich, Martin; Ohmi, Kazuhito; Ohnishi, Yukiyoshi; Ohsawa, Satoshi; Ohuchi, Norihito; Oide, Katsunobu; Okada, Nobuchika; Okamura, Takahiro; Okugi, Toshiyuki; Okumi, Shoji; Okumura, Ken-ichi; Olchevski, Alexander; Oliver, William; Olivier, Bob; Olsen, James; Olsen, Jeff; Olsen, Stephen; Olshevsky, A.G.; Olsson, Jan; Omori, Tsunehiko; Onel, Yasar; Onengut, Gulsen; Ono, Hiroaki; Onoprienko, Dmitry; Oren, Will; Orimoto, Toyoko J.; Oriunno, Marco; Orlandea, Marius Ciprian; Oroku, Masahiro; Orr, Lynne H.; Orr, Robert S.; Oshea, Val; Oskarsson, Anders; Osland, Per; Ossetski, Dmitri; Österman, Lennart; Ostiguy, Francois; Otono, Hidetoshi; Ottewell, Brian; Ouyang, Qun; Padamsee, Hasan; Padilla, Cristobal; Pagani, Carlo; Palmer, Mark A.; Pam, Wei Min; Pande, Manjiri; Pande, Rajni; Pandit, V.S.; Pandita, P.N.; Pandurovic, Mila; Pankov, Alexander; Panzeri, Nicola; Papandreou, Zisis; Paparella, Rocco; Para, Adam; Park, Hwanbae; Parker, Brett; Parkes, Chris; Parma, Vittorio; Parsa, Zohreh; Parsons, Justin; Partridge, Richard; Pasquinelli, Ralph; Pásztor, Gabriella; Paterson, Ewan; Patrick, Jim; Patteri, Piero; Ritchie Patterson, J.; Pauletta, Giovanni; Paver, Nello; Pavlicek, Vince; Pawlik, Bogdan; Payet, Jacques; Pchalek, Norbert; Pedersen, John; Pei, Guo Xi; Pei, Shi Lun; Pelka, Jerzy; Pellegrini, Giulio; Pellett, David; Peng, G.X.; Penn, Gregory; Penzo, Aldo; Perry, Colin; Peskin, Michael; Peters, Franz; Petersen, Troels Christian; Peterson, Daniel; Peterson, Thomas; Petterson, Maureen; Pfeffer, Howard; Pfund, Phil; Phelps, Alan; Van Phi, Quang; Phillips, Jonathan; Phinney, Nan; Piccolo, Marcello; Piemontese, Livio; Pierini, Paolo; Thomas Piggott, W.; Pike, Gary; Pillet, Nicolas; Jayawardena, Talini Pinto; Piot, Phillippe; Pitts, Kevin; Pivi, Mauro; Plate, Dave; Pleier, Marc-Andre; Poblaguev, Andrei; Poehler, Michael; Poelker, Matthew; Poffenberger, Paul; Pogorelsky, Igor; Poirier, Freddy; Poling, Ronald; Poole, Mike; Popescu, Sorina; Popielarski, John; Pöschl, Roman; Postranecky, Martin; Potukochi, Prakash N.; Prast, Julie; Prat, Serge; Preger, Miro; Prepost, Richard; Price, Michael; Proch, Dieter; Puntambekar, Avinash; Qin, Qing; Qu, Hua Min; Quadt, Arnulf; Quesnel, Jean-Pierre; Radeka, Veljko; Rahmat, Rahmat; Rai, Santosh Kumar; Raimondi, Pantaleo; Ramberg, Erik; Ranjan, Kirti; Rao, Sista V.L.S.; Raspereza, Alexei; Ratti, Alessandro; Ratti, Lodovico; Raubenheimer, Tor; Raux, Ludovic; Ravindran, V.; Raychaudhuri, Sreerup; Re, Valerio; Rease, Bill; Reece, Charles E.; Regler, Meinhard; Rehlich, Kay; Reichel, Ina; Reichold, Armin; Reid, John; Reid, Ron; Reidy, James; Reinhard, Marcel; Renz, Uwe; Repond, Jose; Resta-Lopez, Javier; Reuen, Lars; Ribnik, Jacob; Rice, Tyler; Richard, François; Riemann, Sabine; Riemann, Tord; Riles, Keith; Riley, Daniel; Rimbault, Cécile; Rindani, Saurabh; Rinolfi, Louis; Risigo, Fabio; Riu, Imma; Rizhikov, Dmitri; Rizzo, Thomas; Rochford, James H.; Rodriguez, Ponciano; Roeben, Martin; Rolandi, Gigi; Roodman, Aaron; Rosenberg, Eli; Roser, Robert; Ross, Marc; Rossel, François; Rossmanith, Robert; Roth, Stefan; Rougé, André; Rowe, Allan; Roy, Amit; Roy, Sendhunil B.; Roy, Sourov; Royer, Laurent; Royole-Degieux, Perrine; Royon, Christophe; Ruan, Manqi; Rubin, David; Ruehl, Ingo; Jimeno, Alberto Ruiz; Ruland, Robert; Rusnak, Brian; Ryu, Sun-Young; Sabbi, Gian Luca; Sadeh, Iftach; Sadygov, Ziraddin Y; Saeki, Takayuki; Sagan, David; Sahni, Vinod C.; Saini, Arun; Saito, Kenji; Saito, Kiwamu; Sajot, Gerard; Sakanaka, Shogo; Sakaue, Kazuyuki; Salata, Zen; Salih, Sabah; Salvatore, Fabrizio; Samson, Joergen; Sanami, Toshiya; Levi Sanchez, Allister; Sands, William; Santic, John; Sanuki, Tomoyuki; Sapronov, Andrey; Sarkar, Utpal; Sasao, Noboru; Satoh, Kotaro; Sauli, Fabio; Saunders, Claude; Saveliev, Valeri; Savoy-Navarro, Aurore; Sawyer, Lee; Saxton, Laura; Schäfer, Oliver; Schälicke, Andreas; Schade, Peter; Schaetzel, Sebastien; Scheitrum, Glenn; Schibler, Emilie; Schindler, Rafe; Schlösser, Markus; Schlueter, Ross D.; Schmid, Peter; Schmidt, Ringo Sebastian; Schneekloth, Uwe; Schreiber, Heinz Juergen; Schreiber, Siegfried; Schroeder, Henning; Peter Schüler, K.; Schulte, Daniel; Schultz-Coulon, Hans-Christian; Schumacher, Markus; Schumann, Steffen; Schumm, Bruce A.; Schwienhorst, Reinhard; Schwierz, Rainer; Scott, Duncan J.; Scuri, Fabrizio; Sefkow, Felix; Sefri, Rachid; Seguin-Moreau, Nathalie; Seidel, Sally; Seidman, David; Sekmen, Sezen; Seletskiy, Sergei; Senaha, Eibun; Senanayake, Rohan; Sendai, Hiroshi; Sertore, Daniele; Seryi, Andrei; Settles, Ronald; Sever, Ramazan; Shales, Nicholas; Shao, Ming; Shelkov, G.A.; Shepard, Ken; Shepherd-Themistocleous, Claire; Sheppard, John C.; Shi, Cai Tu; Shidara, Tetsuo; Shim, Yeo-Jeong; Shimizu, Hirotaka; Shimizu, Yasuhiro; Shimizu, Yuuki; Shimogawa, Tetsushi; Shin, Seunghwan; Shioden, Masaomi; Shipsey, Ian; Shirkov, Grigori; Shishido, Toshio; Shivpuri, Ram K.; Shrivastava, Purushottam; Shulga, Sergey; Shumeiko, Nikolai; Shuvalov, Sergey; Si, Zongguo; Siddiqui, Azher Majid; Siegrist, James; Simon, Claire; Simrock, Stefan; Sinev, Nikolai; Singh, Bhartendu K.; Singh, Jasbir; Singh, Pitamber; Singh, R.K.; Singh, S.K.; Singini, Monito; Sinha, Anil K.; Sinha, Nita; Sinha, Rahul; Sinram, Klaus; Sissakian, A.N.; Skachkov, N.B.; Skrinsky, Alexander; Slater, Mark; Slominski, Wojciech; Smiljanic, Ivan; Smith, A J Stewart; Smith, Alex; Smith, Brian J.; Smith, Jeff; Smith, Jonathan; Smith, Steve; Smith, Susan; Smith, Tonee; Neville Snodgrass, W.; Sobloher, Blanka; Sohn, Young-Uk; Solidum, Ruelson; Solyak, Nikolai; Son, Dongchul; Sonmez, Nasuf; Sopczak, Andre; Soskov, V.; Spencer, Cherrill M.; Spentzouris, Panagiotis; Speziali, Valeria; Spira, Michael; Sprehn, Daryl; Sridhar, K.; Srivastava, Asutosh; St. Lorant, Steve; Stahl, Achim; Stanek, Richard P.; Stanitzki, Marcel; Stanley, Jacob; Stefanov, Konstantin; Stein, Werner; Steiner, Herbert; Stenlund, Evert; Stern, Amir; Sternberg, Matt; Stockinger, Dominik; Stockton, Mark; Stoeck, Holger; Strachan, John; Strakhovenko, V.; Strauss, Michael; Striganov, Sergei I.; Strologas, John; Strom, David; Strube, Jan; Stupakov, Gennady; Su, Dong; Sudo, Yuji; Suehara, Taikan; Suehiro, Toru; Suetsugu, Yusuke; Sugahara, Ryuhei; Sugimoto, Yasuhiro; Sugiyama, Akira; Suh, Jun Suhk; Sukovic, Goran; Sun, Hong; Sun, Stephen; Sun, Werner; Sun, Yi; Sun, Yipeng; Suszycki, Leszek; Sutcliffe, Peter; Suthar, Rameshwar L.; Suwada, Tsuyoshi; Suzuki, Atsuto; Suzuki, Chihiro; Suzuki, Shiro; Suzuki, Takashi; Swent, Richard; Swientek, Krzysztof; Swinson, Christina; Syresin, Evgeny; Szleper, Michal; Tadday, Alexander; Takahashi, Rika; Takahashi, Tohru; Takano, Mikio; Takasaki, Fumihiko; Takeda, Seishi; Takenaka, Tateru; Takeshita, Tohru; Takubo, Yosuke; Tanaka, Masami; Tang, Chuan Xiang; Taniguchi, Takashi; Tantawi, Sami; Tapprogge, Stefan; Tartaglia, Michael A.; Tassielli, Giovanni Francesco; Tauchi, Toshiaki; Tavian, Laurent; Tawara, Hiroko; Taylor, Geoffrey; Telnov, Alexandre V.; Telnov, Valery; Tenenbaum, Peter; Teodorescu, Eliza; Terashima, Akio; Terracciano, Giuseppina; Terunuma, Nobuhiro; Teubner, Thomas; Teuscher, Richard; Theilacker, Jay; Thomson, Mark; Tice, Jeff; Tigner, Maury; Timmermans, Jan; Titov, Maxim; Toge, Nobukazu; Tokareva, N.A.; Tollefson, Kirsten; Tomasek, Lukas; Tomovic, Savo; Tompkins, John; Tonutti, Manfred; Topkar, Anita; Toprek, Dragan; Toral, Fernando; Torrence, Eric; Traversi, Gianluca; Trimpl, Marcel; Mani Tripathi, S.; Trischuk, William; Trodden, Mark; Trubnikov, G.V.; Tschirhart, Robert; Tskhadadze, Edisher; Tsuchiya, Kiyosumi; Tsukamoto, Toshifumi; Tsunemi, Akira; Tucker, Robin; Turchetta, Renato; Tyndel, Mike; Uekusa, Nobuhiro; Ueno, Kenji; Umemori, Kensei; Ummenhofer, Martin; Underwood, David; Uozumi, Satoru; Urakawa, Junji; Urban, Jeremy; Uriot, Didier; Urner, David; Ushakov, Andrei; Usher, Tracy; Uzunyan, Sergey; Vachon, Brigitte; Valerio, Linda; Valin, Isabelle; Valishev, Alex; Vamra, Raghava; Van der Graaf, Harry; Van Kooten, Rick; Van Zandbergen, Gary; Vanel, Jean-Charles; Variola, Alessandro; Varner, Gary; Velasco, Mayda; Velte, Ulrich; Velthuis, Jaap; Vempati, Sundir K.; Venturini, Marco; Vescovi, Christophe; Videau, Henri; Vila, Ivan; Vincent, Pascal; Virey, Jean-Marc; Visentin, Bernard; Viti, Michele; Vo, Thanh Cuong; Vogel, Adrian; Vogt, Harald; von Toerne, Eckhard; Vorozhtsov, S.B.; Vos, Marcel; Votava, Margaret; Vrba, Vaclav; Wackeroth, Doreen; Wagner, Albrecht; Wagner, Carlos E.M.; Wagner, Stephen; Wake, Masayoshi; Walczak, Roman; Walker, Nicholas J.; Walkowiak, Wolfgang; Wallon, Samuel; Walsh, Roberval; Walston, Sean; Waltenberger, Wolfgang; Walz, Dieter; Wang, Chao En; Wang, Chun Hong; Wang, Dou; Wang, Faya; Wang, Guang Wei; Wang, Haitao; Wang, Jiang; Wang, Jiu Qing; Wang, Juwen; Wang, Lanfa; Wang, Lei; Wang, Min-Zu; Wang, Qing; Wang, Shu Hong; Wang, Xiaolian; Wang, Xue-Lei; Wang, Yi Fang; Wang, Zheng; Wanzenberg, Rainer; Ward, Bennie; Ward, David; Warmbein, Barbara; Warner, David W.; Warren, Matthew; Washio, Masakazu; Watanabe, Isamu; Watanabe, Ken; Watanabe, Takashi; Watanabe, Yuichi; Watson, Nigel; Wattimena, Nanda; Wayne, Mitchell; Weber, Marc; Weerts, Harry; Weiglein, Georg; Weiland, Thomas; Weinzierl, Stefan; Weise, Hans; Weisend, John; Wendt, Manfred; Wendt, Oliver; Wenzel, Hans; Wenzel, William A.; Wermes, Norbert; Werthenbach, Ulrich; Wesseln, Steve; Wester, William; White, Andy; White, Glen R.; Wichmann, Katarzyna; Wienemann, Peter; Wierba, Wojciech; Wilksen, Tim; Willis, William; Wilson, Graham W.; Wilson, John A.; Wilson, Robert; Wing, Matthew; Winter, Marc; Wirth, Brian D.; Wolbers, Stephen A.; Wolff, Dan; Wolski, Andrzej; Woodley, Mark D.; Woods, Michael; Woodward, Michael L.; Woolliscroft, Timothy; Worm, Steven; Wormser, Guy; Wright, Dennis; Wright, Douglas; Wu, Andy; Wu, Tao; Wu, Yue Liang; Xella, Stefania; Xia, Guoxing; Xia, Lei; Xiao, Aimin; Xiao, Liling; Xie, Jia Lin; Xing, Zhi-Zhong; Xiong, Lian You; Xu, Gang; Xu, Qing Jing; Yajnik, Urjit A.; Yakimenko, Vitaly; Yamada, Ryuji; Yamaguchi, Hiroshi; Yamamoto, Akira; Yamamoto, Hitoshi; Yamamoto, Masahiro; Yamamoto, Naoto; Yamamoto, Richard; Yamamoto, Yasuchika; Yamanaka, Takashi; Yamaoka, Hiroshi; Yamazaki, Hideki; Yan, Wenbiao; Yang, Hai-Jun; Yang, Jin Min; Yang, Jongmann; Yang, Zhenwei; Yano, Yoshiharu; Yazgan, Efe; Yeh, G.P.; Yilmaz, Hakan; Yock, Philip; Yoda, Hakutaro; Yoh, John; Yokoya, Kaoru; Yokoyama, Hirokazu; York, Richard C.; Yoshida, Mitsuhiro; Yoshida, Takuo; Yoshioka, Tamaki; Young, Andrew; Yu, Cheng Hui; Yu, Jaehoon; Yu, Xian Ming; Yuan, Changzheng; Yue, Chong-Xing; Yue, Jun Hui; Zacek, Josef; Zagorodnov, Igor; Zalesak, Jaroslav; Zalikhanov, Boris; Zarnecki, Aleksander Filip; Zawiejski, Leszek; Zeitnitz, Christian; Zeller, Michael; Zerwas, Dirk; Zerwas, Peter; Zeyrek, Mehmet; Zhai, Ji Yuan; Zhang, Bao Cheng; Zhang, Bin; Zhang, Chuang; Zhang, He; Zhang, Jiawen; Zhang, Jing; Zhang, Jing Ru; Zhang, Jinlong; Zhang, Liang; Zhang, X.; Zhang, Yuan; Zhang, Zhige; Zhang, Zhiqing; Zhang, Ziping; Zhao, Haiwen; Zhao, Ji Jiu; Zhao, Jing Xia; Zhao, Ming Hua; Zhao, Sheng Chu; Zhao, Tianchi; Zhao, Tong Xian; Zhao, Zhen Tang; Zhao, Zhengguo; Zhou, De Min; Zhou, Feng; Zhou, Shun; Zhu, Shou Hua; Zhu, Xiong Wei; Zhukov, Valery; Zimmermann, Frank; Ziolkowski, Michael; Zisman, Michael S.; Zomer, Fabian; Zong, Zhang Guo; Zorba, Osman; Zutshi, Vishnu

2007-01-01

This article reviews the physics case for the ILC. Baseline running at 500 GeV as well as possible upgrades and options are discussed. The opportunities on Standard Model physics, Higgs physics, Supersymmetry and alternative theories beyond the Standard Model are described.

Analysis of the cool down related cavity performance of the European XFEL vertical acceptance tests

Energy Technology Data Exchange (ETDEWEB)

Wenskat, Marc; Schaffran, J.

2017-09-15

For the European X-Ray Free Electron Laser (XFEL) cavity production, the cold radio-frequency (RF) test of the cavities at 2 K after delivery from the two vendors was the mandatory acceptance test. It has been previously reported, that the cool down dynamics of a cavity across T{sub c} has a significant influence on the observed intrinsic quality factor Q{sub 0}, which is a measure of the losses on the inner cavity surface. A total number of 367 cool downs is used to analyze this correlation and we show that such a correlation is not observed during the European XFEL cavity production.

Comparison of Mesa and Device Diameter Variation in Double Wafer-Fused Multi Quantum-Well, Long-Wavelength, Vertical Cavity Surface Emitting Lasers

International Nuclear Information System (INIS)

Menon, P.S.; Kandiah, K.; Burhanuddin Yeop Majlis; Shaari, S.

2011-01-01

Long-wavelength vertical-cavity surface-emitting lasers (LW-VCSELs) have profound advantages compared to traditional edge-emitting lasers offering improved properties with respect to mode selectivity, fibre coupling, threshold currents and integration into 2D arrays or with other electronic devices. Its commercialization is gaining momentum as the local and access network in optical communication system expand. Numerical modeling of LW-VCSEL utilizing wafer-fused InP-based multi-quantum wells (MQW) and GaAs-based distributed Bragg reflectors (DBRs) is presented in this paper. Emphasis is on the device and mesa/pillar diameter design parameter comparison and its effect on the device characteristics. (author)

Dedicated very front-end electronics for an ILC prototype hadronic calorimeter with SiPM read-out

CERN Document Server

de La Taille, C

2008-01-01

The SPIROC chip is a dedicated very front-end electronics for an ILC prototype hadronic calorimeter with Silicon photomultiplier (or MPPC) readout. This ASIC is due to equip a 10,000-channel demonstrator in 2009. SPIROC is an evolution of FLC_SiPM used for the ILC AHCAL physics prototype [1]. SPIROC was submitted in June 2007 and will be tested in September 2007. It embeds cutting edge features that fulfil ILC final detector requirements. It has been realized in 0.35m SiGe technology. It has been developed to match the requirements of large dynamic range, low noise, low consumption, high precision and large number of readout channels needed. SPIROC is an auto-triggered, bi-gain, 36-channel ASIC which allows to measure on each channel the charge from one photoelectron to 2000 and the time with a 100ps accurate TDC. An analogue memory array with a depth of 16 for each channel is used to store the time information and the charge measurement. A 12-bit Wilkinson ADC has been embedded to digitize the analogue memor...

Quantum Control of a Spin Qubit Coupled to a Photonic Crystal Cavity

Science.gov (United States)

2012-12-01

Cavities in Monocrystalline Diamond. Physical Review Letters 109, 033604 (2012). 14. Kroutvar, M. et al. Optically programmable electron spin...temperatures, varying the detuning of X− from the cavity. The dashed blue lines in panel a are fits to the reflectivity. The spectra are vertically

Silicon Tracker Design for the ILC

International Nuclear Information System (INIS)

Nelson, T.; SLAC

2005-01-01

The task of tracking charged particles in energy frontier collider experiments has been largely taken over by solid-state detectors. While silicon microstrip trackers offer many advantages in this environment, large silicon trackers are generally much more massive than their gaseous counterparts. Because of the properties of the machine itself, much of the material that comprises a typical silicon microstrip tracker can be eliminated from a design for the ILC. This realization is the inspiration for a tracker design using lightweight, short, mass-producible modules to tile closed, nested cylinders with silicon microstrips. This design relies upon a few key technologies to provide excellent performance with low cost and complexity. The details of this concept are discussed, along with the performance and status of the design effort

Enhancement of slope efficiency and output power in GaN-based vertical-cavity surface-emitting lasers with a SiO2-buried lateral index guide

Science.gov (United States)

Kuramoto, Masaru; Kobayashi, Seiichiro; Akagi, Takanobu; Tazawa, Komei; Tanaka, Kazufumi; Saito, Tatsuma; Takeuchi, Tetsuya

2018-03-01

We have achieved a high output power of 6 mW from a 441 nm GaN-based vertical-cavity surface-emitting laser (VCSEL) under continuous wave (CW) operation, by reducing both the internal loss and the reflectivity of the front cavity mirror. A preliminary analysis of the internal loss revealed an enormously high transverse radiation loss in a conventional GaN-based VCSEL without lateral optical confinement (LOC). Introducing an LOC structure enhanced the slope efficiency by a factor of 4.7, with a further improvement to a factor of 6.7 upon reducing the front mirror reflectivity. The result was a slope efficiency of 0.87 W/A and an external differential quantum efficiency of 32% under pulsed operation. A flip-chip-bonded VCSEL also exhibited a high slope efficiency of 0.64 W/A and an external differential quantum efficiency of 23% for the front-side output under CW operation. The reflectivity of the cavity mirror was adjusted by varying the number of AlInN/GaN distributed Bragg reflector pairs from 46 to 42, corresponding to reflectivity values from 99.8% to 99.5%. These results demonstrate that a combination of internal loss reduction and cavity mirror control is a very effective way of obtaining a high output GaN-based VCSEL.

Polarized positrons for the ILC. Update on simulations

Energy Technology Data Exchange (ETDEWEB)

Ushakov, A.; Adeyemi, O.S.; Moortgat-Pick, G. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Staufenbiel, F.; Riemann, S. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

2012-02-15

To achieve the extremely high luminosity for colliding electron-positron beams at the future International Linear Collider [1] (ILC) an undulator-based source with about 230 meters helical undulator and a thin titanium-alloy target rim rotated with tangential velocity of about 100 meters per second are foreseen. The very high density of heat deposited in the target has to be analyzed carefully. The energy deposited by the photon beam in the target has been calculated in FLUKA. The resulting stress in the target material after one bunch train has been simulated in ANSYS. (orig.)

The ILC P2 Marx and Application of the Marx Topology to Future Accelerators

Energy Technology Data Exchange (ETDEWEB)

Kemp, M.A.; Benwell, A.; Burkhart, C.; Hugyik, J.; Larsen, R.; Macken, K.; MacNair, D.; Nguyen, M.; Olsen, J.; /SLAC

2011-08-19

The SLAC P2 Marx is under development as the linac klystron modulator for the ILC. This modulator builds upon the success of the P1 Marx, which is currently undergoing lifetime evaluation. While the SLAC P2 Marx's (henceforth, 'P2 Marx') target application is the ILC, characteristics of the Marx topology make it equally well-suited for operation at different parameter ranges; for example, increased pulse repetition frequency, increased output current, longer pulse width, etc. Marx parameters such as the number of cells, cell capacitance, and component selection can be optimized for the application. This paper provides an overview of the P2 Marx development. In addition, the scalability of the Marx topology to other long-pulse parameter ranges is discussed.

Recommendation for Mitigations of the Electron Cloud Instability in the ILC

International Nuclear Information System (INIS)

Pivi, Mauro

2011-01-01

Electron cloud has been identified as one of the highest priority issues for the international Linear Collider (ILC) Damping Rings (DR). An electron cloud Working Group (WG) has evaluated the electron cloud effect and instability, and mitigation solutions for the electron cloud formation. Working group deliverables include recommendations for the baseline and alternate solutions to the electron cloud formation in various regions of the ILC Positron DR, which is presently assumed to be the 3.2 km design. Detailed studies of a range of mitigation options including coatings, clearing electrodes, grooves and novel concepts, were carried out over the previous several years by nearly 50 researchers, and the results of the studies form the basis for the recommendation. The recommendations are the result of the working group discussions held at numerous meetings and during a dedicated workshop. In addition, a number of items requiring further investigation were identified during the discussions at the Cornell meeting and studies will be carried out at CesrTA, a test accelerator dedicated to electron cloud studies, and other institutions.

Simplified analytical model for thermal transfer in vertical hollow brick

Energy Technology Data Exchange (ETDEWEB)

Lorente, S [Lab. d` Etudes Thermiques et Mecaniques, INSA, UPS, Toulouse (France); Petit, M [Lab. d` Etudes Thermiques et Mecaniques, INSA, UPS, Toulouse (France); Javelas, R [Lab. d` Etudes Thermiques et Mecaniques, INSA, UPS, Toulouse (France)

1996-12-01

A modern building envelope has a lot of little cavities. Most of them are vertical with a high height to thickness ratio. We present here the conception of a software to determine heat transfer through terra-cotta bricks full of large vertical cavities. After a bibliographic study on convective heat transfer in such cavities, we made an analytical model based on Karman-Polhausen`s method for convection and on the radiosity method for radiative heat transfer. We used a test apparatus of a single cavity to determine the temperature field inside the cavity. Using these experimental results, we showed that the exchange was two-dimensional. We also realised heat flux measurements. Then we expose our theoretical study: We propose relations between central core temperatures and active face temperatures, then between outside and inside active face temperatures. We calculate convective superficial heat transfer because we noticed we have boundary layers along the active faces. We realise a heat flux balance between convective plus radiative heat transfer and conductive heat transfer, so we propose an algorithm to calculate global heat transfer through a single cavity. Finally, we extend our model to a whole hollow brick with lined-up cavities and propose an algorithm to calculate heat flux and thermal resistance with a good accuracy ({approx}7.5%) compared to previous experimental results. (orig.)

Study of an ILC Main Linac that Follows the Earth Curvature

CERN Document Server

Eliasson, P; Poirier, F; Schulte, Daniel; Walker, N

2006-01-01

In the base line configuration, the tunnel of the ILC will follow the earth curvature. The emittance growth in a curved main linac has been studied including static and dynamic imperfections. These include effects due to current ripples in the power supplies of the steering coils and the impact of the beam position monitors scale errors.

Optimization of the beam crossing angle at the ILC for e+e‑ and γ γ collisions

Science.gov (United States)

Telnov, V. I.

2018-03-01

At this time, the design of the International Linear Collider (ILC) is optimized for e+e‑ collisions; the photon collider (γ γ and >=) is considered as an option. Unexpected discoveries, such as the diphoton excess digamma(750) seen at the LHC, could strongly motivate the construction of a photon collider. In order to enable the γ γ collision option, the ILC design should be compatible with it from the very beginning. In this paper, we discuss the problem of the beam crossing angle. In the ILC technical design [1], this angle is 14 mrad, which is just enough to provide enough space for the final quadrupoles and outgoing beams. For γ γ collisions, the crossing angle must be larger because the low-energy electrons that result from multiple Compton scattering get large disruption angles in collisions with the opposing electron beam and some deflection in the solenoidal detector field. For a 2E0=500 GeV collider, the required crossing angle is about 25 mrad. In this paper, we consider the factors that determine the crossing angle as well as its minimum permissible value that does not yet cause a considerable reduction of the γ γ luminosity. It is shown that the best solution is to increase the laser wavelength from the current 1 μm (which is optimal for 2E0=500 GeV) to 2 μm as this makes possible achieving high γ γ luminosities at a crossing angle of 20 mrad, which is also quite comfortable for e+e‑ collisions, does not cause any degradation of the e+e‑ luminosity and opens the possibility for a more energetic future collider in the same tunnel (e.g., CLIC). Moreover, the 2 μm wavelength is optimal for a 2E0 = 1 TeV collider, e.g., a possible ILC energy upgrade. Please consider this paper an appeal to increase the ILC crossing angle from 14 to 20 mrad.

Upstream vertical cavity surface-emitting lasers for fault monitoring and localization in WDM passive optical networks

Science.gov (United States)

Wong, Elaine; Zhao, Xiaoxue; Chang-Hasnain, Connie J.

2008-04-01

As wavelength division multiplexed passive optical networks (WDM-PONs) are expected to be first deployed to transport high capacity services to business customers, real-time knowledge of fiber/device faults and the location of such faults will be a necessity to guarantee reliability. Nonetheless, the added benefit of implementing fault monitoring capability should only incur minimal cost associated with upgrades to the network. In this work, we propose and experimentally demonstrate a fault monitoring and localization scheme based on a highly-sensitive and potentially low-cost monitor in conjunction with vertical cavity surface-emitting lasers (VCSELs). The VCSELs are used as upstream transmitters in the WDM-PON. The proposed scheme benefits from the high reflectivity of the top distributed Bragg reflector (DBR) mirror of optical injection-locked (OIL) VCSELs to reflect monitoring channels back to the central office for monitoring. Characterization of the fault monitor demonstrates high sensitivity, low bandwidth requirements, and potentially low output power. The added advantage of the proposed fault monitoring scheme incurs only a 0.5 dB penalty on the upstream transmissions on the existing infrastructure.

Simulations of the Electron Cloud Build Up and Instabilities for Various ILC Damping Ring Configurations

International Nuclear Information System (INIS)

Pivi, Mauro; Raubenheimer, Tor O.; Wang, Lanfa; Ohmi, Kazuhito; Wanzenberg, Rainer; Wolski, Andrzej

2007-01-01

In the beam pipe of the positron damping ring of the International Linear Collider (ILC), an electron cloud may be first produced by photoelectrons and ionization of residual gases and then increased by the secondary emission process. This paper reports the assessment of electron cloud effects in a number of configuration options for the ILC baseline configuration. Careful estimates were made of the secondary electron yield (sometimes in the literature also referred as secondary emission yield SEY or (delta), with a peak value (delta) max ) threshold for electron cloud build-up, and the related single- and coupled-bunch instabilities, as a function of beam current and surface properties for a variety of optics designs. When the configuration for the ILC damping rings was chosen at the end of 2005, the results from these studies were important considerations. On the basis of the joint theoretical and experimental work, the baseline configuration currently specifies a pair of 6 km damping rings for the positron beam, to mitigate the effects of the electron cloud that could present difficulties in a single 6 km ring. However, since mitigation techniques are now estimated to be sufficiently mature, a reduced single 6-km circumference is presently under consideration so as to reduce costs

Probing Higgs-radion mixing in warped models through complementary searches at the LHC and the ILC

Science.gov (United States)

Frank, Mariana; Huitu, Katri; Maitra, Ushoshi; Patra, Monalisa

2016-09-01

We consider the Higgs-radion mixing in the context of warped space extradimensional models with custodial symmetry and investigate the prospects of detecting the mixed radion. Custodial symmetries allow the Kaluza-Klein excitations to be lighter and protect Z b b ¯ to be in agreement with experimental constraints. We perform a complementary study of discovery reaches of the Higgs-radion mixed state at the 13 and 14 TeV LHC and at the 500 and 1000 GeV International Linear Collider (ILC). We carry out a comprehensive analysis of the most significant production and decay modes of the mixed radion in the 80 GeV-1 TeV mass range and indicate the parameter space that can be probed at the LHC and the ILC. There exists a region of the parameter space which can be probed, at the LHC, through the diphoton channel even for a relatively low luminosity of 50 fb-1 . The reach of the four-lepton final state in probing the parameter space is also studied in the context of 14 TeV LHC, for a luminosity of 1000 fb-1 . At the ILC, with an integrated luminosity of 500 fb-1 , we analyze the Z -radion associated production and the W W fusion production, followed by the radion decay into b b ¯ and W+W-. The W W fusion production is favored over the Z -radion associated channel in probing regions of the parameter space beyond the LHC reach. The complementary study at the LHC and the ILC is useful both for the discovery of the radion and the understanding of its mixing sector.

Pb{sub 1–x}Eu{sub x}Te alloys (0 ⩽ x ⩽ 1) as materials for vertical-cavity surface-emitting lasers in the mid-infrared spectral range of 4–5 μm

Energy Technology Data Exchange (ETDEWEB)

Pashkeev, D. A., E-mail: d.pashkeev@gmail.com; Selivanov, Yu. G.; Chizhevskii, E. G.; Zasavitskiy, I. I. [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation)

2016-02-15

The optical properties of epitaxial layers and heterostructures based on Pb{sub 1–x}Eu{sub x}Te alloys (0 ⩽ x ⩽ 1) are analyzed in the context of designing Bragg mirrors and vertical-cavity surface-emitting lasers for the midinfrared spectral range. It is shown that the optimal heteropair for laser microcavities is Pb{sub 1–x}Eu{sub x}Te(x ≈ 0.06)/EuTe. On the basis of this heteropair, highly reflective Bragg mirrors consisting of just three periods and featuring a reflectance of R ⩾ 99.8% at the center of the stop band are grown by molecular-beam epitaxy on BaF{sub 2} (111) substrates. Single-mode optically pumped vertical-cavity surface-emitting lasers for the 4–5 μm spectral range operating at liquid-nitrogen temperatures are demonstrated.

Forward instrumentation for ILC detectors

Energy Technology Data Exchange (ETDEWEB)

Abramowicz, Halina [Tel Aviv Univ. (Israel); Abusleme, Angel [Stanford Univ., CA (United States); Afanaciev, Konstantin [NCPHEP, Minsk (BY)] (and others)

2010-09-15

Two special calorimeters are foreseen for the instrumentation of the very forward region of the ILC detector, a luminometer designed to measure the rate of low angle Bhabha scattering events with a precision better than 10{sup -3} and a low polar angle calorimeter, adjacent to the beam-pipe. The latter will be hit by a large amount of beamstrahlung remnants. The amount and shape of these depositions will allow a fast luminosity estimate and the determination of beam parameters. The sensors of this calorimeter must be radiation hard. Both devices will improve the hermeticity of the detector in the search for new particles. Finely segmented and very compact calorimeters will match the requirements. Due to the high occupancy fast front-end electronics is needed. The design of the calorimeters developed and optimised with Monte Carlo simulations is presented. Sensors and readout electronics ASICs have been designed and prototypes are available. Results on the performance of these major components are summarised. (orig.)

Forward instrumentation for ILC detectors

International Nuclear Information System (INIS)

Abramowicz, Halina; Abusleme, Angel; Afanaciev, Konstantin

2010-09-01

Two special calorimeters are foreseen for the instrumentation of the very forward region of the ILC detector, a luminometer designed to measure the rate of low angle Bhabha scattering events with a precision better than 10 -3 and a low polar angle calorimeter, adjacent to the beam-pipe. The latter will be hit by a large amount of beamstrahlung remnants. The amount and shape of these depositions will allow a fast luminosity estimate and the determination of beam parameters. The sensors of this calorimeter must be radiation hard. Both devices will improve the hermeticity of the detector in the search for new particles. Finely segmented and very compact calorimeters will match the requirements. Due to the high occupancy fast front-end electronics is needed. The design of the calorimeters developed and optimised with Monte Carlo simulations is presented. Sensors and readout electronics ASICs have been designed and prototypes are available. Results on the performance of these major components are summarised. (orig.)

Forward Instrumentation for ILC Detectors

CERN Document Server

Abramowicz, Halina; Afanaciev, Konstantin; Aguilar, Jonathan; Ambalathankandy, Prasoon; Bambade, Philip; Bergholz, Matthias; Bozovic-Jelisavcic, Ivanka; Castro, Elena; Chelkov, Georgy; Coca, Cornelia; Daniluk, Witold; Dragone, Angelo; Dumitru, Laurentiu; Elsener, Konrad; Emeliantchik, Igor; Fiutowski, Tomasz; Gostkin, Mikhail; Grah, Christian; Grzelak, Grzegorz; Haller, Gunter; Henschel, Hans; Ignatenko, Alexandr; Idzik, Marek; Ito, Kazutoshi; Jovin, Tatjana; Kielar, Eryk; Kotula, Jerzy; Krumstein, Zinovi; Kulis, Szymon; Lange, Wolfgang; Lohmann, Wolfgang; Levy, Aharon; Moszczynski, Arkadiusz; Nauenberg, Uriel; Novgorodova, Olga; Ohlerich, Marin; Orlandea, Marius; Oleinik, Gleb; Oliwa, Krzysztof; Olshevski, Alexander; Pandurovic, Mila; Pawlik, Bogdan; Przyborowski, Dominik; Sato, Yutaro; Sadeh, Iftach; Sailer, Andre; Schmidt, Ringo; Schumm, Bruce; Schuwalow, Sergey; Smiljanic, Ivan; Swientek, Krzysztof; Takubo, Yosuke; Teodorescu, Eliza; Wierba, Wojciech; Yamamoto, Hitoshi; Zawiejski, Leszek; Zhang, Jinlong

2010-01-01

Two special calorimeters are foreseen for the instrumentation of the very forward region of the ILC detector, a luminometer designed to measure the rate of low angle Bhabha scattering events with a precision better than 10-3 and a low polar angle calorimeter, adjacent to the beam-pipe. The latter will be hit by a large amount of beamstrahlung remnants. The amount and shape of these depositions will allow a fast luminosity estimate and the determination of beam parameters. The sensors of this calorimeter must be radiation hard. Both devices will improve the hermeticity of the detector in the search for new particles. Finely segmented and very compact calorimeters will match the requirements. Due to the high occupancy fast front-end electronics is needed. The design of the calorimeters developed and optimised with Monte Carlo simulations is presented. Sensors and readout electronics ASICs have been designed and prototypes are available. Results on the performance of these major components are summarised.

Spread of smoke and heat along narrow air cavity in double-skin façade fires

Directory of Open Access Journals (Sweden)

Chow Lun Cheuk

2014-01-01

Full Text Available A scenario on double-skin façade fire was identified earlier for hazard assessment. A flashover room fire occurred next to the façade, broke the interior glass pane and spread to the façade cavity. As observed in experiments, hot gas moved up as a vertical channel flow for narrow façade cavity. Heat and smoke spread along the narrow air cavity of a double-skin façade will be studied in this paper. A simple mathematical model is developed from basic heat transfer theory for studying the vertical air temperature profiles of the hot gas flowing along the cavity. Assuming one-dimensional flow for hot gas moving up the façade cavity, conservation equations on mass and enthalpy were solved. Experimental results on two double-skin façade rigs of height 6 m and 15 m with narrow cavity depth were used to justify the results. A total of 11 tests were carried out. Correlation expressions between cavity air temperature and the height above ceiling of the fire room were derived.

A lateral cephalometric study of pharyngeal cavity in Korean adults

International Nuclear Information System (INIS)

Lee, Sang Rae

1976-01-01

A study was performed to investigate the size of pharyngeal cavity and sexual differences between Korean adult mal e and female by introducing linear analysis of the lateral cephalogram. The radiograms were composed of 46 adult male aged 24.64 and 52 adult female aged 22.74 respectively. In order to study and measure the pharyngeal area, the following skeletal landmarks were selected: S,N,A,Ptm, B,H,H', M ,S-N, FH and CV, and the angle CV-FH was measured to provide a factor for correction of error resulting from improper he ad positioning of subjects, especially in the relative positions of A and H, while radiography. All points to be measured were projected at right angles to the Frankfort plane. For the purpose of measuring the anteroposterior dimensions of pharyngeal cavity the distances were measured in A-Ptm, A-S, S-Ptm and CV-H, and vertical measurements were made in SN-A, SN-PNS, SN-H' and M-H. The obtained results were as follows: 1. The pharyngeal cavity is broader in the vertical than in the anteroposterior diameter in both sex and the maximum sexual differences were showed in the distances between SN and H', and minimal sexual differences in the distances between S and Ptm. 2. In general, the measurements of male were larger than those of female in the anteroposterior dimensions of pharyngea l cavity, but the distances between A and S, between CV and H showed significant sexual differences when evaluated statistically. 3. All of the measurements were larger in male than in female in vertical dimensions of pharyngeal cavity, and there were statistical significances of sexual differences in all variables.

A lateral cephalometric study of pharyngeal cavity in Korean adults

Energy Technology Data Exchange (ETDEWEB)

Lee, Sang Rae [Department of Dental Radiology, College of Dentistry, Kyung Hee University, Seoul (Korea, Republic of)

1976-11-15

A study was performed to investigate the size of pharyngeal cavity and sexual differences between Korean adult mal e and female by introducing linear analysis of the lateral cephalogram. The radiograms were composed of 46 adult male aged 24.64 and 52 adult female aged 22.74 respectively. In order to study and measure the pharyngeal area, the following skeletal landmarks were selected: S,N,A,Ptm, B,H,H', M ,S-N, FH and CV, and the angle CV-FH was measured to provide a factor for correction of error resulting from improper he ad positioning of subjects, especially in the relative positions of A and H, while radiography. All points to be measured were projected at right angles to the Frankfort plane. For the purpose of measuring the anteroposterior dimensions of pharyngeal cavity the distances were measured in A-Ptm, A-S, S-Ptm and CV-H, and vertical measurements were made in SN-A, SN-PNS, SN-H' and M-H. The obtained results were as follows: 1. The pharyngeal cavity is broader in the vertical than in the anteroposterior diameter in both sex and the maximum sexual differences were showed in the distances between SN and H', and minimal sexual differences in the distances between S and Ptm. 2. In general, the measurements of male were larger than those of female in the anteroposterior dimensions of pharyngea l cavity, but the distances between A and S, between CV and H showed significant sexual differences when evaluated statistically. 3. All of the measurements were larger in male than in female in vertical dimensions of pharyngeal cavity, and there were statistical significances of sexual differences in all variables.

Impact of calibration errors on CMB component separation using FastICA and ILC

Science.gov (United States)

Dick, Jason; Remazeilles, Mathieu; Delabrouille, Jacques

2010-01-01

The separation of emissions from different astrophysical processes is an important step towards the understanding of observational data. This topic of component separation is of particular importance in the observation of the relic cosmic microwave background (CMB) radiation, as performed by the Wilkinson Microwave Anisotropy Probe satellite and the more recent Planck mission, launched on 2009 May 14 from Kourou and currently taking data. When performing any sort of component separation, some assumptions about the components must be used. One assumption that many techniques typically use is knowledge of the frequency scaling of one or more components. This assumption may be broken in the presence of calibration errors. Here we compare, in the context of imperfect calibration, the recovery of a clean map of emission of the CMB from observational data with two methods: FastICA (which makes no assumption of the frequency scaling of the components) and an `Internal Linear Combination' (ILC), which explicitly extracts a component with a given frequency scaling. We find that even in the presence of small calibration errors (less than 1 per cent) with a Planck-style mission, the ILC method can lead to inaccurate CMB reconstruction in the high signal-to-noise ratio regime, because of partial cancellation of the CMB emission in the recovered map. While there is no indication that the failure of the ILC will translate to other foreground cleaning or component separation techniques, we propose that all methods which assume knowledge of the frequency scaling of one or more components be careful to estimate the effects of calibration errors.

Design of half-reentrant SRF cavities

International Nuclear Information System (INIS)

Meidlinger, M.; Grimm, T.L.; Hartung, W.

2006-01-01

The shape of a TeSLA inner cell can be improved to lower the peak surface magnetic field at the expense of a higher peak surface electric field by making the cell reentrant. Such a single-cell cavity was designed and tested at Cornell, setting a world record accelerating gradient [V. Shemelin et al., An optimized shape cavity for TESLA: concept and fabrication, 11th Workshop on RF Superconductivity, Travemuende, Germany, September 8-12, 2003; R. Geng, H. Padamsee, Reentrant cavity and first test result, Pushing the Limits of RF Superconductivity Workshop, Argonne National Laboratory, September 22-24, 2004]. However, the disadvantage to a cavity is that liquids become trapped in the reentrant portion when it is vertically hung during high pressure rinsing. While this was overcome for Cornell's single-cell cavity by flipping it several times between high pressure rinse cycles, this may not be feasible for a multi-cell cavity. One solution to this problem is to make the cavity reentrant on only one side, leaving the opposite wall angle at six degrees for fluid drainage. This idea was first presented in 2004 [T.L. Grimm et al., IEEE Transactions on Applied Superconductivity 15(6) (2005) 2393]. Preliminary designs of two new half-reentrant (HR) inner cells have since been completed, one at a high cell-to-cell coupling of 2.1% (high-k cc HR) and the other at 1.5% (low-k cc HR). The parameters of a HR cavity are comparable to a fully reentrant cavity, with the added benefit that a HR cavity can be easily cleaned with current technology

Occurrence, frequency, and significance of cavities in fractured-rock aquifers near Oak Ridge National Laboratory, Tennessee

International Nuclear Information System (INIS)

Moore, G.K.

1988-01-01

Virtually all wells drilled into bedrock intercept a water-bearing fracture, but cavities occur only in areas underlaid by limy rocks. Multiple cavities are common in wells in the Conasauga and Knox Groups but are rare in the Rome Formation and the Chickamauga Group. The geometric mean height (vertical dimension) of the cavities is 0.59 m, the geometric mean depth is 14 m, the average lateral spatial frequency is 0.16, and the average vertical spatial frequency is 0.019. Differences in cavity parameter values are caused partly by geologic factors such as lithology, bed thickness, and spatial fracture frequency. However, hydrologic factors such as percolation rate, recharge amount, aquifer storage capacity, and differences between lateral and vertical permeability may also be important. Tracer tests show that groundwater velocity in some cavities is in the range 20-300 m/d, and relatively rapid flow rates occur near springs. In contrast, wells that intercept cavities have about the same range in hydraulic conductivity as wells in regolith and fractured rock. The hydraulic conductivity data indicate a flow rate of less than 1.0 m/d. This difference cannot be adequately explained, but rapid groundwater movement may be much more common above the water table than below. Rapid groundwater flows below the water table might be rare except near springs in the Knox Group. 10 refs., 3 figs., 4 tabs

High-power, format-flexible, 885-nm vertical-cavity surface-emitting laser arrays

Science.gov (United States)

Wang, Chad; Talantov, Fedor; Garrett, Henry; Berdin, Glen; Cardellino, Terri; Millenheft, David; Geske, Jonathan

2013-03-01

High-power, format flexible, 885 nm vertical-cavity surface-emitting laser (VCSEL) arrays have been developed for solid-state pumping and illumination applications. In this approach, a common VCSEL size format was designed to enable tiling into flexible formats and operating configurations. The fabrication of a common chip size on ceramic submount enables low-cost volume manufacturing of high-power VCSEL arrays. This base VCSEL chip was designed to be 5x3.33 mm2, and produced up to 50 Watts of peak continuous wave (CW) power. To scale to higher powers, multiple chips can be tiled into a combination of series or parallel configurations tailored to the application driver conditions. In actively cooled CW operation, the VCSEL array chips were packaged onto a single water channel cooler, and we have demonstrated 0.5x1, 1x1, and 1x3 cm2 formats, producing 150, 250, and 500 Watts of peak power, respectively, in under 130 A operating current. In QCW operation, the 1x3 cm2 VCSEL module, which contains 18 VCSEL array chips packaged on a single water cooler, produced over 1.3 kW of peak power. In passively cooled packages, multiple chip configurations have been developed for illumination applications, producing over 300 Watts of peak power in QCW operating conditions. These VCSEL chips use a substrate-removed structure to allow for efficient thermal heatsinking to enable high-power operation. This scalable, format flexible VCSEL architecture can be applied to wavelengths ranging from 800 to 1100 nm, and can be used to tailor emission spectral widths and build high-power hyperspectral sources.

The correction of the littlest Higgs model to the Higgs production process e+e-→e+e-H at the ILC

International Nuclear Information System (INIS)

Wang, Xuelei; Liu, Yaobei; Chen, Jihong; Yang, Hua

2007-01-01

The littlest Higgs model is the most economical one among various little Higgs models. In the context of the littlest Higgs model, we study the process e + e - →e + e - H at the ILC and calculate the correction of the littlest Higgs model to the cross section of this process. The results show that, in the favorable parameter spaces preferred by the electroweak precision data, the value of the relative correction is in the range from a few percent to tens percent. In most cases, the correction is large enough to reach the measurement precision of the ILC. Therefore, the correction of the littlest Higgs model to the process e + e - →e + e - H might be detected at the ILC, which will give an ideal way to test the model. (orig.)

The Development and Psychometric Properties of the Immigration Law Concerns Scale (ILCS) for HIV Testing.

Science.gov (United States)

Lechuga, Julia; Galletly, Carol L; Broaddus, Michelle R; Dickson-Gomez, Julia B; Glasman, Laura R; McAuliffe, Timothy L; Vega, Miriam Y; LeGrand, Sarah; Mena, Carla A; Barlow, Morgan L; Valera, Erik; Montenegro, Judith I

2017-11-08

To develop, pilot test, and conduct psychometric analyses of an innovative scale measuring the influence of perceived immigration laws on Latino migrants' HIV-testing behavior. The Immigration Law Concerns Scale (ILCS) was developed in three phases: Phase 1 involved a review of law and literature, generation of scale items, consultation with project advisors, and subsequent revision of the scale. Phase 2 involved systematic translation- back translation and consensus-based editorial processes conducted by members of a bilingual and multi-national study team. In Phase 3, 339 sexually active, HIV-negative Spanish-speaking, non-citizen Latino migrant adults (both documented and undocumented) completed the scale via audio computer-assisted self-interview. The psychometric properties of the scale were tested with exploratory factor analysis and estimates of reliability coefficients were generated. Bivariate correlations were conducted to test the discriminant and predictive validity of identified factors. Exploratory factor analysis revealed a three-factor, 17-item scale. subscale reliability ranged from 0.72 to 0.79. There were significant associations between the ILCS and the HIV-testing behaviors of participants. Results of the pilot test and psychometric analysis of the ILCS are promising. The scale is reliable and significantly associated with the HIV-testing behaviors of participants. Subscales related to unwanted government attention and concerns about meeting moral character requirements should be refined.

EFFECT OF DISCRETE HEATER AT THE VERTICAL WALL OF THE CAVITY OVER THE HEAT TRANSFER AND ENTROPY GENERATION USING LBM

Directory of Open Access Journals (Sweden)

Mousa Farhadi

2011-01-01

Full Text Available In this paper Lattice Boltzmann Method (LBM was employed for investigation the effect of the heater location on flow pattern, heat transfer and entropy generation in a cavity. A 2D thermal lattice Boltzmann model with 9 velocities, D2Q9, is used to solve the thermal flow problem. The simulations were performed for Rayleigh numbers from 103 to 106 at Pr = 0.71. The study was carried out for heater length of 0.4 side wall length which is located at the right side wall. Results are presented in the form of streamlines, temperature contours, Nusselt number and entropy generation curves. Results show that the location of heater has a great effect on the flow pattern and temperature fields in the enclosure and subsequently on entropy generation. The dimensionless entropy generation decreases at high Rayleigh number for all heater positions. The ratio of averaged Nusselt number and dimensionless entropy generation for heater located on vertical and horizontal walls was calculated. Results show that higher heat transfer was observed from the cold walls when the heater located on vertical wall. On the other hand, heat transfer increases from the heater surface when it located on the horizontal wall.

Wavelength-controlled external-cavity laser with a silicon photonic crystal resonant reflector

Science.gov (United States)

Gonzalez-Fernandez, A. A.; Liles, Alexandros A.; Persheyev, Saydulla; Debnath, Kapil; O'Faolain, Liam

2016-03-01

We report the experimental demonstration of an alternative design of external-cavity hybrid lasers consisting of a III-V Semiconductor Optical Amplifier with fiber reflector and a Photonic Crystal (PhC) based resonant reflector on SOI. The Silicon reflector comprises a polymer (SU8) bus waveguide vertically coupled to a PhC cavity and provides a wavelength-selective optical feedback to the laser cavity. This device exhibits milliwatt-level output power and sidemode suppression ratio of more than 25 dB.

Design, Construction, and Initial Test of High Spatial Resolution Thermometry Arrays for Detection of Surface Temperature Profiles on SRF Cavities in Super Fluid Helium

Energy Technology Data Exchange (ETDEWEB)

Ari Palczewski, Rongli Geng, Grigory Eremeev

2011-07-01

We designed and built two high resolution (0.6-0.55mm special resolution [1.1-1.2mm separation]) thermometry arrays prototypes out of the Allen Bradley 90-120 ohm 1/8 watt resistor to measure surface temperature profiles on SRF cavities. One array was designed to be physically flexible and conform to any location on a SRF cavity; the other was modeled after the common G-10/stycast 2850 thermometer and designed to fit on the equator of an ILC (Tesla 1.3GHz) SRF cavity. We will discuss the advantages and disadvantages of each array and their construction. In addition we will present a case study of the arrays performance on a real SRF cavity TB9NR001. TB9NR001 presented a unique opportunity to test the performance of each array as it contained a dual (4mm separation) cat eye defect which conventional methods such as OST (Oscillating Superleak second-sound Transducers) and full coverage thermometry mapping were unable to distinguish between. We will discuss the new arrays ability to distinguish between the two defects and their preheating performance.

The first fully functional 3D CMOS chip with Deep N-well active pixel sensors for the ILC vertex detector

International Nuclear Information System (INIS)

Traversi, G.; Gaioni, L.; Manazza, A.; Manghisoni, M.; Ratti, L.; Re, V.

2013-01-01

This work presents the characterization of Deep N-well (DNW) active pixel sensors fabricated in a vertically integrated technology. The DNW approach takes advantage of the triple well structure to lay out a sensor with relatively large charge collecting area (as compared to standard three transistor MAPS), while the readout is performed by a classical signal processing chain for capacitive detectors. This new 3D design relies upon stacking two homogeneous tiers fabricated in a 130 nm CMOS process where the top tier is thinned down to about 12μm to expose through silicon vias (TSV), therefore making connection to the buried circuits possible. This technology has been used to design a fine pitch 3D CMOS sensor with sparsification capabilities, in view of vertexing applications to the International Linear Collider (ILC) experiments. Results from the characterization of different kind of test structures, including single pixels, 3×3 and 8×8 matrices, are presented

The Higgs-strahlung and double Higgs-strahlung production in the left-right twin Higgs model at the ILC

International Nuclear Information System (INIS)

Yao-Bei, Liu; Hong-Mei, Han; Xue-Lei, Wang

2008-01-01

The Higgs-strahlung process e + e - → ZH and the double Higgs-strahlung process e + e - → ZHH are very important for studying Higgs boson properties and the Higgs self-coupling in the high-energy e + e - collider (ILC). We calculate the contributions of the left-right twin Higgs (LRTH) model to these processes and find that, in the favorable parameter spaces, the LRTH model can generate significant corrections to the production cross-section of these processes. We expect that the possible signals of the LRTH model can be detected via these processes in the future ILC experiments. (authors)

Analysis of the Qualification-Tests Performance of the Superconducting Cavities for the SNS Linac

CERN Document Server

Delayen, J R; Ozelis, O

2004-01-01

Thomas Jefferson National Accelerating Facility (Jefferson Lab) is producing superconducting radio frequency (SRF) cryomodules for the Spallation Neutron Source (SNS) cold linac. This consists of 11 medium-beta (β=0.61) cyomodules of 3 cavities each, and 12 high-beta (β=0.81) cryomodules of 4 cavities each. Before assembly into cavity strings the cavities undergo individual qualification tests in a vertical cryostat (VTA). In this paper we analyze the performance of the cavities during these qualification tests, and attempt to correlate this performance with cleaning, assembly, and testing procedures. We also compare VTA performance with performance in completed cryomodules.

Results of Cavity Series Fabrication at Jefferson Laboratory for the Cryomodule 'R100'

International Nuclear Information System (INIS)

Marhauser, F.; Clemens, W.A.; Drury, M.A.; Forehand, D.; Henry, J.; Manning, S.; Overton, R.B.; Williams, R.S.

2011-01-01

A series production of eight superconducting RF cavities for the cryomodule R100 was conducted at JLab in 2010. The cavities underwent chemical post-processing prior to vertical high power testing and routinely exceeded the envisaged performance specifications. After cryomodule assembly, cavities were successfully high power acceptance tested. In this paper, we present the achievements paving the way for the first demonstration of 100 MV (and beyond) in a single cryomodule to be operated at CEBAF.

Free convection performance of circular cavities having two active curved vertical sides and two inactive curved horizontal sides

International Nuclear Information System (INIS)

Ridouane, El Hassan; Campo, Antonio

2006-01-01

A detailed review of the archival reveals that the heat transfer and fluid flow characteristics of circular cavities have not been investigated so far and of course their physical features are not understood. A prominent application of these cavities arises in the miniaturized packaging of electronic components that are subject to strict constraints. This paper addresses primarily steady-state laminar natural convection of air in a circular cavity of diameter H inscribed in a square cavity of side H where the corresponding sides are in contact at four points. A third cavity, an arc-square cavity whose shape lies between the square and circular cavity shapes is included in the analysis. The finite volume method is used to perform the numerical simulations. The methodology takes into account the second-order-accurate QUICK scheme for the discretization of the convective term, whereas the pressure-velocity coupling is handled with the SIMPLE scheme. Since the air is not assumed a Boussinesq gas, it was decided to take all thermophysical properties as temperature-dependent. In the end, it has been demonstrated that the circular cavity possesses a superior balance between heat transfer enhancement and size in cross-section area in comparison with the standard square cavity. The side of the square cavity is similar to the diameter of the circular cavity

Vertical electro-absorption modulator design and its integration in a VCSEL

Science.gov (United States)

Marigo-Lombart, L.; Calvez, S.; Arnoult, A.; Thienpont, H.; Almuneau, G.; Panajotov, K.

2018-04-01

Electro-absorption modulators, either embedded in CMOS technology or integrated with a semiconductor laser, are of high interest for many applications such as optical communications, signal processing and 3D imaging. Recently, the integration of a surface-normal electro-absorption modulator into a vertical-cavity surface-emitting laser has been considered. In this paper we implement a simple quantum well electro-absorption model and design and optimize an asymmetric Fabry-Pérot semiconductor modulator while considering all physical properties within figures of merit. We also extend this model to account for the impact of temperature on the different parameters involved in the calculation of the absorption, such as refractive indices and exciton transition broadening. Two types of vertical modulator structures have been fabricated and experimentally characterized by reflectivity and photocurrent measurements demonstrating a very good agreement with our model. Finally, preliminary results of an electro-absorption modulator vertically integrated with a vertical-cavity surface-emitting laser device are presented, showing good modulation performances required for high speed communications.

Design, prototyping, and testing of a compact superconducting double quarter wave crab cavity

Science.gov (United States)

Xiao, Binping; Alberty, Luis; Belomestnykh, Sergey; Ben-Zvi, Ilan; Calaga, Rama; Cullen, Chris; Capatina, Ofelia; Hammons, Lee; Li, Zenghai; Marques, Carlos; Skaritka, John; Verdu-Andres, Silvia; Wu, Qiong

2015-04-01

We proposed a novel design for a compact superconducting crab cavity with a double quarter wave (DQWCC) shape. After fabrication and surface treatments, this niobium proof-of-principle cavity was tested cryogenically in a vertical cryostat. The cavity is extremely compact yet has a low frequency of 400 MHz, an essential property for service in the Large Hadron Collider luminosity upgrade. The cavity's electromagnetic properties are well suited for this demanding task. The demonstrated deflecting voltage of 4.6 MV is well above the required 3.34 MV for a crab cavity in the future High Luminosity LHC. In this paper, we present the design, prototyping, and results from testing the DQWCC.

A large area Micromegas TPC for tracking at the ILC

International Nuclear Information System (INIS)

Wang, Wenxin

2013-01-01

The study of the fundamental building blocks of matter necessitates always more powerful accelerators. New particles are produced in high energy collisions of protons or electrons. The by-Products of these collisions are detected in large apparatus surrounding the interaction point. The 125 GeV Higgs particle discovered at LHC will be studied in detail in the next e + e - collider. The leading project for this is called ILC. The team that I joined is working on the R and D for a Time Projection Chamber (TPC) to detect the charged tracks by the ionization they leave in a gas volume, optimised for use at ILC. This primary ionization is amplified by the so-Called Micromegas device, with a charge-Sharing anode made of a resistive-Capacitive coating. After a presentation of the physics motivation for the ILC and ILD detector, I will review the principle of operation of a TPC (Chapter 2) and underline the advantages of the Micromegas readout with charge sharing. The main part of this PhD work concerns the detailed study of up to 12 prototypes of various kinds. The modules and their readout electronics are described in Chapter 3. A test-Bench setup has been assembled at CERN (Chapter 4) to study the response to a 55 Fe source, allowing an energy calibration and a uniformity study. In Chapter 5, the ion back-flow is studied using a bulk Micromegas and the gas gain is measured using a calibrated electronics chain. With the same setup, the electron transparency is measured as a function of the field ratio (drift/amplification). Also, several beam tests have been carried out at DESY with a 5 GeV electron beam in a 1 T superconducting magnet. These beam tests allowed the detailed study of the spatial resolution. In the final test, the endplate was equipped with seven modules, bringing sensitivity to misalignment and distortions. Such a study required software developments (Chapter 6) to make optimal use of the charge sharing and to reconstruct multiple tracks through several

The Mechanical Behavior of Bone Cement in THR in the Presense of Cavities

Directory of Open Access Journals (Sweden)

A. Benouis

2014-06-01

Full Text Available In this work we analyze three-dimensionally using the finite element method, the level and the Von Mises stress equivalent distribution induced around a cavity and between two cavities located in the proximal and distal bone cement polymethylmethacrylate (PMMA. The effects of the position around two main axes (vertical and horizontal of the cavity with respect to these axes, of the cavity - cavity interdistance and of the type of loading (static on the mechanical behavior of cement orthopedic are highlighted. We show that the breaking strain of the cement is largely taken when the cement in its proximal-lateral part contains cavities very close adjacent to each other. This work highlights not only the effect of the density of cavities, in our case simulated by cavity-cavity interdistance, but also the nature of the activity of the patient (patient standing corresponding to static efforts on the mechanical behavior of cement.

In search of new phenomena using polarization. HERA and ILC

International Nuclear Information System (INIS)

Helebrant, Christian

2009-12-01

The longitudinal polarization of leptons can be used as an important tool in the search for new phenomena at particle colliders. In the first part of this thesis a search for first generation leptoquarks at the H1 experiment is presented. During the HERA-2 runperiod polarized lepton beams were used. The analysis presented herein utilizes this fact in order to enhance the sensitivity to these chirally coupling leptoquarks. Since no evidence for their existence is found, exclusion limits depending on the mass and Yukawa coupling are calculated. This analysis can exclude leptoquarks coupling at electromagnetic strength up to masses of 280-300 GeV, depending on the leptoquark quantum numbers. A new domain of physics is expected to be open to the planned electron positron linear collider ILC, where polarized lepton beams will play an important role. In order to fully exploit its physics potential, the polarization will have to be measured with an as yet unequaled precision of 0.25%, which is expected to be limited by systematic effects, like the nonlinearity of the photodetectors employed. In the second part of this thesis several methods are tested with respect to their capability to resolve photodetector nonlinearities at the permille level, and checked for their long term stability. With some of the methods presented herein it will be possible to measure and correct photodetector nonlinearities at a running ILC experiment with the accuracy required in order to achieve the aimed precision of the polarization measurement. (orig.)

In search of new phenomena using polarization. HERA and ILC

Energy Technology Data Exchange (ETDEWEB)

Helebrant, Christian

2009-12-15

The longitudinal polarization of leptons can be used as an important tool in the search for new phenomena at particle colliders. In the first part of this thesis a search for first generation leptoquarks at the H1 experiment is presented. During the HERA-2 runperiod polarized lepton beams were used. The analysis presented herein utilizes this fact in order to enhance the sensitivity to these chirally coupling leptoquarks. Since no evidence for their existence is found, exclusion limits depending on the mass and Yukawa coupling are calculated. This analysis can exclude leptoquarks coupling at electromagnetic strength up to masses of 280-300 GeV, depending on the leptoquark quantum numbers. A new domain of physics is expected to be open to the planned electron positron linear collider ILC, where polarized lepton beams will play an important role. In order to fully exploit its physics potential, the polarization will have to be measured with an as yet unequaled precision of 0.25%, which is expected to be limited by systematic effects, like the nonlinearity of the photodetectors employed. In the second part of this thesis several methods are tested with respect to their capability to resolve photodetector nonlinearities at the permille level, and checked for their long term stability. With some of the methods presented herein it will be possible to measure and correct photodetector nonlinearities at a running ILC experiment with the accuracy required in order to achieve the aimed precision of the polarization measurement. (orig.)

Mid infrared resonant cavity detectors and lasers with epitaxial lead-chalcogenides

Science.gov (United States)

Zogg, H.; Rahim, M.; Khiar, A.; Fill, M.; Felder, F.; Quack, N.

2010-09-01

Wavelength tunable emitters and detectors in the mid-IR wavelength region allow applications including thermal imaging and gas spectroscopy. One way to realize such tunable devices is by using a resonant cavity. By mechanically changing the cavity length with MEMS mirror techniques, the wavelengths may be tuned over a considerable range. Resonant cavity enhanced detectors (RCED) are sensitive at the cavity resonance only. They may be applied for low resolution spectroscopy, and, when arrays of such detectors are realized, as multicolour IR-FPA or "IR-AFPA", adaptive focal plane arrays. We report the first room temperature mid-IR VECSEL (vertical external cavity surface emitting laser) with a wavelength above 3 μm. The active region is just 850 nm PbSe, followed by a 2.5 pair Bragg mirror. Output power is > 10 mW at RT.

Vortex capturing vertical axis wind turbine

International Nuclear Information System (INIS)

Zannetti, L; Gallizio, F; Ottino, G

2007-01-01

An analytical-numerical study is presented for an innovative lift vertical axis turbine whose blades are designed with vortex trapping cavities that act as passive flow control devices. The unsteady flow field past one-bladed and two-bladed turbines is described by a combined analytical and numerical method based on conformal mapping and on a blob vortex method

Attractor hopping between polarization dynamical states in a vertical-cavity surface-emitting laser subject to parallel optical injection

Science.gov (United States)

Denis-le Coarer, Florian; Quirce, Ana; Valle, Angel; Pesquera, Luis; Rodríguez, Miguel A.; Panajotov, Krassimir; Sciamanna, Marc

2018-03-01

We present experimental and theoretical results of noise-induced attractor hopping between dynamical states found in a single transverse mode vertical-cavity surface-emitting laser (VCSEL) subject to parallel optical injection. These transitions involve dynamical states with different polarizations of the light emitted by the VCSEL. We report an experimental map identifying, in the injected power-frequency detuning plane, regions where attractor hopping between two, or even three, different states occur. The transition between these behaviors is characterized by using residence time distributions. We find multistability regions that are characterized by heavy-tailed residence time distributions. These distributions are characterized by a -1.83 ±0.17 power law. Between these regions we find coherence enhancement of noise-induced attractor hopping in which transitions between states occur regularly. Simulation results show that frequency detuning variations and spontaneous emission noise play a role in causing switching between attractors. We also find attractor hopping between chaotic states with different polarization properties. In this case, simulation results show that spontaneous emission noise inherent to the VCSEL is enough to induce this hopping.

Conceptual Design of ILC Damping Ring Wiggler Straight Vacuum System

International Nuclear Information System (INIS)

Marks, S.; Kennedy, K.; Plate, D.; Schlueter, R.D.; Zisman, M.

2007-01-01

The positron and electron damping rings for the International Linear Collider will contain long straight sections consisting of twenty wiggler/quadrupole pairs. The wigglers will be based upon the CESR superconducting design. There are a number of challenges associated with the design of the wiggler straight vacuum system, in particular, the absorption of photon power generated by the wigglers. This paper will present the overall conceptual design of the wiggler straight vacuum system developed for the ILC Reference Design Report. Particular emphasis will be placed on photon power load calculations and the absorber design

Reservatsioonide lubatavus ning reservatsioonide vastuväidete õiguslik mõju ILC uurimistöö valguses : [bakalaureusetöö] / Marja-Liisa Laatsit ; Tartu Ülikool, õigusteaduskond ; juhendaja: Lauri Mälksoo

Index Scriptorium Estoniae

Laatsit, Marja-Liisa

2009-01-01

ILC = International Law Commission. - Reservatsioonidest tänases teoorias ja praktikas, vastuväidetest reservatsioonide tegemisele, reservatsioonide lubatavusest ja nende õiguslikust mõjust (ILC eriraportöör Pellet̀ettepanekutest, NATO SOFA lepingust)

Transient heating and entropy generation of a fluid inside a large aspect ratio cavity

International Nuclear Information System (INIS)

Cajas, J.C.; Trevino, C.

2013-01-01

In this work, the transient heating of a fluid inside a vertical cavity of large aspect ratio (height/length) was studied numerically by the use of the SIMPLE algorithm. The heat sources are two vertical plates localized in the side walls of the cavity near the bottom. Calculations were performed for a fixed value of the Prandtl number, Pr = 7, aspect ratio of 12 and six different Rayleigh numbers between 10 3 and 10 6 . The temperature and entropy production fields, the non-dimensional heat flux on the heated plates (given by the average Nusselt number) have been obtained. From a clear dependence on the Rayleigh number, different mechanisms of symmetry break and heat transfer in the cavity were found, where vortices dynamics play a very important role. A universal behavior of the mean values of the overall reduced entropy production rate was found, valid after a short initial transient. (authors)

Industrialization of the nitrogen-doping preparation for SRF cavities for LCLS-II

Science.gov (United States)

Gonnella, D.; Aderhold, S.; Burrill, A.; Daly, E.; Davis, K.; Grassellino, A.; Grimm, C.; Khabiboulline, T.; Marhauser, F.; Melnychuk, O.; Palczewski, A.; Posen, S.; Ross, M.; Sergatskov, D.; Sukhanov, A.; Trenikhina, Y.; Wilson, K. M.

2018-03-01

The Linac Coherent Light Source II (LCLS-II) is a new state-of-the-art coherent X-ray source being constructed at SLAC National Accelerator Laboratory. It employs 280 superconducting radio frequency (SRF) cavities in order operate in continuous wave (CW) mode. To reduce the overall cryogenic cost of such a large accelerator, nitrogen-doping of the SRF cavities is being used. Nitrogen-doping has consistently been shown to increase the efficiency of SRF cavities operating in the 2.0 K regime and at medium fields (15-20 MV/m) in vertical cavity tests and horizontal cryomodule tests. While nitrogen-doping's efficacy for improvement of cavity performance was demonstrated at three independent labs, Fermilab, Jefferson Lab, and Cornell University, transfer of the technology to industry for LCLS-II production was not without challenges. Here we present results from the beginning of LCLS-II cavity production. We discuss qualification of the cavity vendors and the first cavities from each vendor. Finally, we demonstrate that nitrogen-doping has been successfully transferred to SRF cavity vendors, resulting in consistent production of cavities with better cryogenic efficiency than has ever been achieved for a large-scale accelerator.

Buffer Chemical Polishing and RF Testing of the 56 MHz SRF Cavity

Energy Technology Data Exchange (ETDEWEB)

Burrill,A.

2009-01-01

The 56 MHz cavity presents a unique challenge in preparing it for RF testing prior to construction of the cryomodule. This challenge arises due to the physical dimensions and subsequent weight of the cavity, and is further complicated by the coaxial geometry, and the need to properly chemically etch and high pressure rinse the entire inner surface prior to RF testing. To the best of my knowledge, this is the largest all niobium SRF cavity to be chemically etched and subsequently tested in a vertical dewar at 4K, and these processes will be the topic of this technical note.

Control of emitted light polarization in a 1310 nm dilute nitride spin-vertical cavity surface emitting laser subject to circularly polarized optical injection

Energy Technology Data Exchange (ETDEWEB)

Alharthi, S. S., E-mail: ssmalh@essex.ac.uk; Hurtado, A.; Al Seyab, R. K.; Henning, I. D.; Adams, M. J. [School of Computer Science and Electronic Engineering, University of Essex, Wivenhoe Park, Colchester CO4 3SQ (United Kingdom); Korpijarvi, V.-M.; Guina, M. [Optoelectronics Research Centre (ORC), Tampere University of Technology, P.O. Box 692, FIN-33101 Tampere (Finland)

2014-11-03

We experimentally demonstrate the control of the light polarization emitted by a 1310 nm dilute nitride spin-Vertical Cavity Surface Emitting Laser (VCSEL) at room temperature. This is achieved by means of a combination of polarized optical pumping and polarized optical injection. Without external injection, the polarization of the optical pump controls that of the spin-VCSEL. However, the addition of the externally injected signal polarized with either left- (LCP) or right-circular polarization (RCP) is able to control the polarization of the spin-VCSEL switching it at will to left- or right-circular polarization. A numerical model has been developed showing a very high degree of agreement with the experimental findings.

A novel nano-sensor based on optomechanical crystal cavity

Science.gov (United States)

Zhang, Yeping; Ai, Jie; Ma, Jingfang

2017-10-01

Optical devices based on new sensing principle are widely used in biochemical and medical area. Nowadays, mass sensing based on monitoring the frequency shifts induced by added mass in oscillators is a well-known and widely used technique. It is interesting to note that for nanoscience and nanotechnology applications there is a strong demand for very sensitive mass sensors, being the target a sensor for single molecule detection. The desired mass resolution for very few or even single molecule detection, has to be below the femtogram range. Considering the strong interaction between high co-localized optical mode and mechanical mode in optomechanical crystal (OMC) cavities, we investigate OMC splitnanobeam cavities in silicon operating near at the 1550nm to achieve high optomechanical coupling rate and ultra-small motion mass. Theoretical investigations of the optical and mechanical characteristic for the proposed cavity are carried out. By adjusting the structural parameters, the cavity's effective motion mass below 10fg and mechanical frequency exceed 10GHz. The transmission spectrum of the cavity is sensitive to the sample which located on the center of the cavity. We conducted the fabrication and the characterization of this cavity sensor on the silicon-on-insulator (SOI) chip. By using vertical coupling between the tapered fiber and the SOI chip, we measured the transmission spectrum of the cavity, and verify this cavity is promising for ultimate precision mass sensing and detection.

CrossRef Energy Reconstruction in a High Granularity Semi-Digital Hadronic Calorimeter for ILC Experiments

CERN Document Server

Mannai, S; Cortina, E; Laktineh, I

2016-01-01

Abstract: The Semi-Digital Hadronic CALorimeter (SDHCAL) is one of the two hadronic calorimeter options proposed by the International Large Detector (ILD) project for the future International Linear Collider (ILC) experiments. It is a sampling calorimeter with 48 active layers made of Glass Resistive Plate Chambers (GRPCs) and their embedded electronics. A fine lateral segmentation is obtained thanks to pickup pads of 1 cm2. This ensures the high granularity required for the application of the Particle Flow Algorithm (PFA) in order to improve the jet energy resolution in the ILC experiments. The performance of the SDHCAL technological prototype was tested successfully in several beam tests at CERN. The main point to be discussed here concerns the energy reconstruction in SDHCAL. Based on Monte Carlo simulation of the SDHCAL prototype using the GEANT4 package, we present different energy reconstruction methods to study the energy linearity and resolution of the detector response to single hadrons. In particula...

Beam orbit control in TESLA superconducting cavities from dipole mode measurements

International Nuclear Information System (INIS)

Paparella, R.

2006-09-01

The knowledge of the electromagnetic interaction between a beam and the surrounding vacuum chamber is necessary in order to optimize the accelerator performance in terms of stored current. Many instability phenomena may occur in the machine because of the fields produced by the beam and acting back on itself. Basically, these fields, wake-fields, produce an extra voltage, affecting the longitudinal dynamics, and a transverse kick which deflects the beam. In this thesis we present the results of theoretical and experimental investigations to demonstrate the possibility of using the dipolar wake fields of the superconducting accelerating to measure the beam transverse position. After an introduction to the ILC project and to the TESLA technology, of superconducting RF cavities, we will approach the problem from an analytical point of view in chapter 2. The expression of the wake fields in a cylindrical cavity will be investigated and the electromagnetic field modes derived from Maxwell equations in an original way. Graphical solutions of a Matlab program simulating the fields due to a particle passing through a pill-box cavity along a generic path will be shown. The interaction of the beam with higher order modes (HOM) in the TESLA cavities has been studied in the past at the TESLA Test Facility (TTF) in order to determine whether the modes with the highest loss factor are sufficiently damped. Starting from the results obtained before 2003, HOM signals has been better observed and examined in order to use dipole modes to find the electric center of each cavity in the first TTF accelerating module. The results presented in chapter 3 will show that by monitoring the HOM signal amplitude for two polarizations of a dipole mode, one can measure electrical center of the modes with a resolution of 50 μm. Moreover, a misalignment of the first TTF module with respect to the gun axis has been predicted using cavity dipole modes. Alternatives to this method are described in

Dynamical dispersion engineering in coupled vertical cavities employing a high-contrast grating

DEFF Research Database (Denmark)

Taghizadeh, Alireza; Chung, Il-Sug

2017-01-01

, including a case capable of dynamically controlling the photon’s effective mass to a large extent while keeping the resonance frequency same. We believe that full-control and dynamical-tuning of the photon’s effective mass may enable new possibilities for cavity quantum electrodynamics studies...

Engineering design of vertical test stand cryostat

International Nuclear Information System (INIS)

Suhane, S.K.; Sharma, N.K.; Raghavendra, S.; Joshi, S.C.; Das, S.; Kush, P.K.; Sahni, V.C.; Gupta, P.D.; Sylvester, C.; Rabehl, R.; Ozelis, J.

2011-01-01

Under Indian Institutions and Fermilab collaboration, Raja Ramanna Centre for Advanced Technology and Fermi National Accelerator Laboratory are jointly developing 2K Vertical Test Stand (VTS) cryostats for testing SCRF cavities at 2K. The VTS cryostat has been designed for a large testing aperture of 86.36 cm for testing of 325 MHz Spoke resonators, 650 MHz and 1.3 GHz multi-cell SCRF cavities for Fermilab's Project-X. Units will be installed at Fermilab and RRCAT and used to test cavities for Project-X. A VTS cryostat comprises of liquid helium (LHe) vessel with internal magnetic shield, top insert plate equipped with cavity support stand and radiation shield, liquid nitrogen (LN 2 ) shield and vacuum vessel with external magnetic shield. The engineering design and analysis of VTS cryostat has been carried out using ASME B and PV Code and Finite Element Analysis. Design of internal and external magnetic shields was performed to limit the magnetic field inside LHe vessel at the cavity surface 2 shield has been performed to check the effectiveness of LN 2 cooling and for compliance with ASME piping code allowable stresses.

Design studies and sensor tests for the beam calorimeter of the ILC detector

International Nuclear Information System (INIS)

Kuznetsova, E.

2007-03-01

The International Linear Collider (ILC) is being designed to explore particle physics at the TeV scale. The design of the Very Forward Region of the ILC detector is considered in the presented work. The Beam Calorimeter - one of two electromagnetic calorimeters situated there - is the subject of this thesis. The Beam Calorimeter has to provide a good hermeticity for high energy electrons, positrons and photons down to very low polar angles, serve for fast beam diagnostics and shield the inner part of the detector from backscattered beamstrahlung remnants and synchrotron radiation. As a possible technology for the Beam Calorimeter a diamond-tungsten sandwich calorimeter is considered. Detailed simulation studies are done in order to explore the suitability of the considered design for the Beam Calorimeter objectives. Detection efficiency, energy and angular resolution for electromagnetic showers are studied. At the simulation level the diamondtungsten design is shown to match the requirements on the Beam Calorimeter performance. Studies of polycrystalline chemical vapour deposition (pCVD) diamond as a sensor material for the Beam Calorimeter are done to explore the properties of the material. Results of the measurements performed with pCVD diamond samples produced by different manufacturers are presented. (orig.)

The global electroweak fit at NNLO and prospects for the LHC and ILC

International Nuclear Information System (INIS)

Baak, M.; Hoecker, A.; Cuth, J.; Schott, M.; Haller, J.; Kogler, R.; Moenig, K.; Stelzer, J.

2014-01-01

For a long time, global fits of the electroweak sector of the standard model (SM) have been used to exploit measurements of electroweak precision observables at lepton colliders (LEP, SLC), together with measurements at hadron colliders (Tevatron, LHC) and accurate theoretical predictions at multi-loop level, to constrain free parameters of the SM, such as the Higgs and top masses. Today, all fundamental SM parameters entering these fits are experimentally determined, including information on the Higgs couplings, and the global fits are used as powerful tools to assess the validity of the theory and to constrain scenarios for new physics. Future measurements at the Large Hadron Collider (LHC) and the International Linear Collider (ILC) promise to improve the experimental precision of key observables used in the fits. This paper presents updated electroweak fit results using the latest NNLO theoretical predictions and prospects for the LHC and ILC. The impact of experimental and theoretical uncertainties is analysed in detail. We compare constraints from the electroweak fit on the Higgs couplings with direct LHC measurements, and we examine present and future prospects of these constraints using a model with modified couplings of the Higgs boson to fermions and bosons. (orig.)

Design studies and sensor tests for the beam calorimeter of the ILC detector

Energy Technology Data Exchange (ETDEWEB)

Kuznetsova, E.

2007-03-15

The International Linear Collider (ILC) is being designed to explore particle physics at the TeV scale. The design of the Very Forward Region of the ILC detector is considered in the presented work. The Beam Calorimeter - one of two electromagnetic calorimeters situated there - is the subject of this thesis. The Beam Calorimeter has to provide a good hermeticity for high energy electrons, positrons and photons down to very low polar angles, serve for fast beam diagnostics and shield the inner part of the detector from backscattered beamstrahlung remnants and synchrotron radiation. As a possible technology for the Beam Calorimeter a diamond-tungsten sandwich calorimeter is considered. Detailed simulation studies are done in order to explore the suitability of the considered design for the Beam Calorimeter objectives. Detection efficiency, energy and angular resolution for electromagnetic showers are studied. At the simulation level the diamondtungsten design is shown to match the requirements on the Beam Calorimeter performance. Studies of polycrystalline chemical vapour deposition (pCVD) diamond as a sensor material for the Beam Calorimeter are done to explore the properties of the material. Results of the measurements performed with pCVD diamond samples produced by different manufacturers are presented. (orig.)

Quasilinear infiltration from an elliptical cavity

Science.gov (United States)

Kuhlman, Kristopher L.; Warrick, Arthur W.

2008-08-01

We develop analytic solutions to the linearized steady-state Richards equation for head and total flowrate due to an elliptic cylinder cavity with a specified pressure head boundary condition. They are generalizations of the circular cylinder cavity solutions of Philip [Philip JR. Steady infiltration from circular cylindrical cavities. Soil Sci Soc Am J 1984;48:270-8]. The circular and strip sources are limiting cases of the elliptical cylinder solution, derived for both horizontally- and vertically-aligned ellipses. We give approximate rational polynomial expressions for total flowrate from an elliptical cylinder over a range of sizes and shapes. The exact elliptical solution is in terms of Mathieu functions, which themselves are generalizations of and computed from trigonometric and Bessel functions. The required Mathieu functions are computed from a matrix eigenvector problem, a modern approach that is straightforward to implement using available linear algebra libraries. Although less efficient and potentially less accurate than the iterative continued fraction approach, the matrix approach is simpler to understand and implement and is valid over a wider parameter range.

HF power couplers for pulsed superconducting cavity resonators; Coupleurs de puissance HF pour cavites supraconductrices en mode pulse

Energy Technology Data Exchange (ETDEWEB)

Jenhani, Hassen [Laboratoire de l' Accelerateur Lineaire, IN2P3-CNRS et Universite de Paris-Sud, BP 34, F-91898 Orsay Cedex (France)

2006-11-15

Recent years have seen an impressive improvement in the accelerating gradients obtained in superconducting cavities. Consequently, such cavities have become attractive candidates for large superconducting linear accelerator projects such as the European XFEL and the International Linear Collider (ILC). As a result, there is a strong interest in reducing RF conditioning time and improving the performance of the input power couplers for these cavities. The so-called TTF-III input power coupler, adopted for the XFEL superconducting RF cavities are complex components. In order to better understand the behavior of this component we have performed a series of experiments on a number of such couplers. Initially, we developed a fully automated RF high power test stand for coupler conditioning procedure. Following this, we performed a series of coupler conditioning tests. This has allowed the study of the coupler behavior during processing. A number of experiments were carried out to evaluate the in-situ baking effect on the conditioning time. Some of the conditioned couplers were sent to DESY in order to be tested on 9-cells TESLA cavities under cryogenic conditions. These tests have shown that the couplers in no way limit the cavity performance, even up to gradients of 35 MV/m. The main objective of our coupler studies was the reduction of their conditioning time, which represents one of the most important criteria in the choice of coupler for high energy linacs. Excellent progress in reducing the conditioning time has been demonstrated by making appropriate modifications to the conditioning procedure. Furthermore, special attention was paid to electron generation processes in the couplers, via multipacting. Simulations of this process were made on both the TTF-III coupler and on a new coupler prototype, TTF-V. Experiments aimed at suppressing multipacting were also successfully achieved by using a DC bias on the inner conductor of the co-axial coupler. (author)

An efficient approach to characterizing and calculating carrier loss due to heating and barrier height variation in vertical-cavity surface-emitting lasers

International Nuclear Information System (INIS)

Jian, Wu; Summers, H. D.

2010-01-01

It is important to determine quantitatively the internal carrier loss arising from heating and barrier height variation in a vertical-cavity surface-emitting quantum well laser (VCSEL). However, it is generally difficult to realize this goal using purely theoretical formulas due to difficulty in deriving the parameters relating to the quantum well structure. In this paper, we describe an efficient approach to characterizing and calculating the carrier loss due to the heating and the barrier height change in the VCSEL. In the method, the thermal carrier loss mechanism is combined with gain measurement and calculation. The carrier loss is re-characterized in a calculable form by constructing the threshold current and gain detuning-related loss current using the measured gain data and then substituting them for the quantum well-related parameters in the formula. The result can be expressed as a product of an exponential weight factor linked to the barrier height change and the difference between the threshold current and gain detuning-related loss current. The gain variation at cavity frequency due to thermal carrier loss and gain detuning processes is measured by using an AlInGaAs–AlGaAs VCSEL structure. This work provides a useful approach to analysing threshold and loss properties of the VCSEL, particularly, gain offset design for high temperature operation of VCSELs. (classical areas of phenomenology)

International Linear Collider Reference Design Report Volume 2: Physics at the ILC

Energy Technology Data Exchange (ETDEWEB)

Aarons, Gerald; Abe, Toshinori; Abernathy, Jason; Ablikim, Medina; Abramowicz, Halina; Adey, David; Adloff, Catherine; Adolphsen, Chris; Afanaciev, Konstantin; Agapov, Ilya; Ahn, Jung-Keun; Aihara, Hiroaki; Akemoto, Mitsuo; del Carmen Alabau, Maria; Albert, Justin; Albrecht, Hartwig; Albrecht, Michael; Alesini, David; Alexander, Gideon; Alexander, Jim; Allison, Wade; /SLAC /Tokyo U. /Victoria U. /Beijing, Inst. High Energy Phys. /Tel Aviv U. /Birmingham U. /Annecy, LAPP /Minsk, High Energy Phys. Ctr. /DESY /Royal Holloway, U. of London /CERN /Pusan Natl. U. /KEK, Tsukuba /Orsay, LAL /Notre Dame U. /Frascati /Cornell U., Phys. Dept. /Oxford U. /Hefei, CUST /Bangalore, Indian Inst. Sci. /Fermilab

2011-11-14

The triumph of 20th century particle physics was the development of the Standard Model and the confirmation of many of its aspects. Experiments determined the particle constituents of ordinary matter, and identified four forces that hold matter together and transform it from one form to another. Particle interactions were found to obey precise laws of relativity and quantum theory. Remarkable features of quantum physics were observed, including the real effects of 'virtual' particles on the visible world. Building on this success, particle physicists are now able to address questions that are even more fundamental, and explore some of the deepest mysteries in science. The scope of these questions is illustrated by this summary from the report Quantum Universe: (1) Are there undiscovered principles of nature; (2) How can we solve the mystery of dark energy; (3) Are there extra dimensions of space; (4) Do all the forces become one; (5) Why are there so many particles; (6) What is dark matter? How can we make it in the laboratory; (7) What are neutrinos telling us; (8) How did the universe begin; and (9) What happened to the antimatter? A worldwide program of particle physics investigations, using multiple approaches, is already underway to explore this compelling scientific landscape. As emphasized in many scientific studies, the International Linear Collider is expected to play a central role in what is likely to be an era of revolutionary advances. Discoveries from the ILC could have breakthrough impact on many of these fundamental questions. Many of the scientific opportunities for the ILC involve the Higgs particle and related new phenomena at Terascale energies. The Standard Model boldly hypothesizes a new form of Terascale energy, called the Higgs field, that permeates the entire universe. Elementary particles acquire mass by interacting with this field. The Higgs field also breaks a fundamental electroweak force into two forces, the electromagnetic

International Linear Collider Reference Design Report. Volume 2: Physics at the ILC

International Nuclear Information System (INIS)

Aarons, Gerald; Abe, Toshinori; Abernathy, Jason; Ablikim, Medina; Abramowicz, Halina; Adey, David; Adloff, Catherine; Adolphsen, Chris; Afanaciev, Konstantin; Agapov, Ilya

2011-01-01

The triumph of 20th century particle physics was the development of the Standard Model and the confirmation of many of its aspects. Experiments determined the particle constituents of ordinary matter, and identified four forces that hold matter together and transform it from one form to another. Particle interactions were found to obey precise laws of relativity and quantum theory. Remarkable features of quantum physics were observed, including the real effects of 'virtual' particles on the visible world. Building on this success, particle physicists are now able to address questions that are even more fundamental, and explore some of the deepest mysteries in science. The scope of these questions is illustrated by this summary from the report Quantum Universe: (1) Are there undiscovered principles of nature; (2) How can we solve the mystery of dark energy; (3) Are there extra dimensions of space; (4) Do all the forces become one; (5) Why are there so many particles; (6) What is dark matter? How can we make it in the laboratory; (7) What are neutrinos telling us; (8) How did the universe begin; and (9) What happened to the antimatter? A worldwide program of particle physics investigations, using multiple approaches, is already underway to explore this compelling scientific landscape. As emphasized in many scientific studies, the International Linear Collider is expected to play a central role in what is likely to be an era of revolutionary advances. Discoveries from the ILC could have breakthrough impact on many of these fundamental questions. Many of the scientific opportunities for the ILC involve the Higgs particle and related new phenomena at Terascale energies. The Standard Model boldly hypothesizes a new form of Terascale energy, called the Higgs field, that permeates the entire universe. Elementary particles acquire mass by interacting with this field. The Higgs field also breaks a fundamental electroweak force into two forces, the electromagnetic and weak

Resonant cavity light-emitting diodes based on dielectric passive cavity structures

Science.gov (United States)

Ledentsov, N.; Shchukin, V. A.; Kropp, J.-R.; Zschiedrich, L.; Schmidt, F.; Ledentsov, N. N.

2017-02-01

A novel design for high brightness planar technology light-emitting diodes (LEDs) and LED on-wafer arrays on absorbing substrates is proposed. The design integrates features of passive dielectric cavity deposited on top of an oxide- semiconductor distributed Bragg reflector (DBR), the p-n junction with a light emitting region is introduced into the top semiconductor λ/4 DBR period. A multilayer dielectric structure containing a cavity layer and dielectric DBRs is further processed by etching into a micrometer-scale pattern. An oxide-confined aperture is further amended for current and light confinement. We study the impact of the placement of the active region into the maximum or minimum of the optical field intensity and study an impact of the active region positioning on light extraction efficiency. We also study an etching profile composed of symmetric rings in the etched passive cavity over the light emitting area. The bottom semiconductor is an AlGaAs-AlAs multilayer DBR selectively oxidized with the conversion of the AlAs layers into AlOx to increase the stopband width preventing the light from entering the semiconductor substrate. The approach allows to achieve very high light extraction efficiency in a narrow vertical angle keeping the reasonable thermal and current conductivity properties. As an example, a micro-LED structure has been modeled with AlGaAs-AlAs or AlGaAs-AlOx DBRs and an active region based on InGaAlP quantum well(s) emitting in the orange spectral range at 610 nm. A passive dielectric SiO2 cavity is confined by dielectric Ta2O5/SiO2 and AlGaAs-AlOx DBRs. Cylindrically-symmetric structures with multiple ring patterns are modeled. It is demonstrated that the extraction coefficient of light to the air can be increased from 1.3% up to above 90% in a narrow vertical angle (full width at half maximum (FWHM) below 20°). For very small oxide-confined apertures 100nm the narrowing of the FWHM for light extraction can be reduced down to 5�

Design, prototyping, and testing of a compact superconducting double quarter wave crab cavity

Directory of Open Access Journals (Sweden)

Binping Xiao

2015-04-01

Full Text Available We proposed a novel design for a compact superconducting crab cavity with a double quarter wave (DQWCC shape. After fabrication and surface treatments, this niobium proof-of-principle cavity was tested cryogenically in a vertical cryostat. The cavity is extremely compact yet has a low frequency of 400 MHz, an essential property for service in the Large Hadron Collider luminosity upgrade. The cavity’s electromagnetic properties are well suited for this demanding task. The demonstrated deflecting voltage of 4.6 MV is well above the required 3.34 MV for a crab cavity in the future High Luminosity LHC. In this paper, we present the design, prototyping, and results from testing the DQWCC.

Development of ultra-light pixelated ladders for an ILC vertex detector

CERN Document Server

Chon-Sen, N.; Claus, G.; De Masi, R.; Deveaux, M.; Dulinski, W.; Goffe, M.; Goldstein, J.; Gregor, I.-M.; Hu-Guo, Ch.; Imhoff, M.; Muntz, C.; Nomerotski, A.; Santos, C.; Schrader, C.; Specht, M.; Stroth, J.; Winter, M.

2010-01-01

The development of ultra-light pixelated ladders is motivated by the requirements of the ILD vertex detector at ILC. This paper summarizes three projects related to system integration. The PLUME project tackles the issue of assembling double-sided ladders. The SERWIETE project deals with a more innovative concept and consists in making single-sided unsupported ladders embedded in an extra thin plastic enveloppe. AIDA, the last project, aims at building a framework reproducing the experimental running conditions where sets of ladders could be tested.

Construction and present status of KEKB superconducting cavities

International Nuclear Information System (INIS)

Tajima, T.; Akai, K.; Ezura, E; Furuya, T.; Hosoyama, K.; Mitsunobu, S.

2000-01-01

The superconducting cavity (SCC) for KEKB is 508 MHz single-cell cavity that has large beam pipes (22 cm and 30 cm i.d.) so that higher-order modes propagate out of the cavity and be absorbed by a lossy material. The input coupler is the TRISTAN-type coaxial one with some modifications such that dc bias voltage can be applied to avoid multipactoring during beam operation, fins to efficiently cool the outer conductor and a heater to remove condensed gases. The higher-order mode absorber is made of ferrite directly sinter-bonded on the inner surface of the copper pipe using a technique called Hot Isostatic Press (HIP). One prototype cavity was tested up to 0.57 A at TRISTAN Accumulation Ring (AR) in 1996. Then, four cavities were constructed for KEKB. One of the cavities achieved an accelerating field of 19 MV/m at a test in a vertical cryostat; this field is the world record at this frequency to our knowledge. No degradation of the field after assembly into horizontal cryostats was observed up to the available power of 300 kW that corresponds to ∼12 MV/m. These four cavities were installed in KEKB tunnel and are expected to supply 6 MV in total voltage to the 1.1 A electron beam in high energy ring (HER). Since beam commissioning started in Dec. 1998, the system has been supplying 6 MV and working very smoothly without any trouble. The maximum current has been 0.51 A and power delivered to beam per cavity is 370-380 kW/cavity up to the end of Apr., 1999. (author)

Low Emittance Guns for the ILC Polarized Electron Beam

International Nuclear Information System (INIS)

Clendenin, J. E.; Brachmann, A.; Ioakeimidi, K.; Kirby, R. E.; Maruyama, T.; Miller, R. H.; Wang, J. W.; Zhou, F.

2007-01-01

Polarized electron beams generated by DC guns are routinely available at several accelerators including JLAB, Mainz and SLAC. These guns operate with a cathode bias on the order of -100 kV. To minimize space charge effects, relatively long bunches are generated at the gun and then compressed longitudinally external to the gun just before and during initial acceleration. For linear colliders, this compression is accomplished using a combination of rf bunchers. For the basic design of the International Linear Collider (ILC), a 120 kV DC photocathode gun is used to produce a series of nanosecond bunches that are each compressed by two sub-harmonic bunchers (SHBs) followed by an L-band buncher and capture section. The longitudinal bunching process results in a significantly higher emittance than produced by the gun alone. While high-energy experiments using polarized beams are not generally sensitive to the source emittance, there are several benefits to a lower source emittance including a simpler more efficient injector system and a lower radiation load during transport especially at bends as at the damping ring. For the ILC, the SHBs could be eliminated if the voltage of the gun is raised sufficiently. Simulations using the General Particle Tracer (GPT) package indicate that a cathode bias voltage of ≥200 kV should allow both SHBs to be operated at 433 or even 650 MHz, while ≥500 kV would be required to eliminate the SHBs altogether. Simulations can be used to determine the minimum emittance possible if the injector is designed for a given increased voltage. A possible alternative to the DC gun is an rf gun. Emittance compensation, routinely used with rf guns, is discussed for higher-voltage DC guns

Low Emittance Guns for the ILC Polarized Electron Beam

International Nuclear Information System (INIS)

Clendenin, J.E.; Brachmann, A.; Ioakeimidi, K.; Kirby, R.E.; Maruyama, T.; Miller, R.H.; Wang, J.W.; Zhou, F.; SLAC

2006-01-01

Polarized electron beams generated by DC guns are routinely available at several accelerators including JLAB, Mainz and SLAC. These guns operate with a cathode bias on the order of -100 kV. To minimize space charge effects, relatively long bunches are generated at the gun and then compressed longitudinally external to the gun just before and during initial acceleration. For linear colliders, this compression is accomplished using a combination of rf bunchers. For the basic design of the International Linear Collider (ILC), a 120 kV DC photocathode gun is used to produce a series of nanosecond bunches that are each compressed by two sub-harmonic bunchers (SHBs) followed by an L-band buncher and capture section. The longitudinal bunching process results in a significantly higher emittance than produced by the gun alone. While high-energy experiments using polarized beams are not generally sensitive to the source emittance, there are several benefits to a lower source emittance including a simpler more efficient injector system and a lower radiation load during transport especially at bends as at the damping ring. For the ILC, the SHBs could be eliminated if the voltage of the gun is raised sufficiently. Simulations using the General Particle Tracer (GPT) package indicate that a cathode bias voltage of (ge)200 kV should allow both SHBs to be operated at 433 or even 650 MHz, while (ge)500 kV would be required to eliminate the SHBs altogether. Simulations can be used to determine the minimum emittance possible if the injector is designed for a given increased voltage. A possible alternative to the DC gun is an rf gun. Emittance compensation, routinely used with rf guns, is discussed for higher-voltage DC guns

High power tests of the prototype 352 MHz beta 0.85 five cell cavity for the TRASCO project

International Nuclear Information System (INIS)

Chiaveri, E.; Losito, R.; Calatroni, S.

2003-01-01

The Five-cell beta 0.85 cavities built at CERN for the development of the TRASCO project is fully tested at the CERN SL-CT Test Bench. The cavity, built using the standard Niobium on Copper technique, was previously tested in a vertical cryostat, showing Qo and Field exceeding the design goal for the TRASCO Project (2.5x10 9 and 5.5 MV/m at 4.5 K). After the successful test we decided to check the performances of the cavity installed in a horizontal Cryostat and equipped with a LEP-II Type high power main coupler and HOM couplers. The cavity was equipped with the Helium Tank, Tuners and couplers at CERN and tested at the SL-CT facility at CERN under a collaboration agreement between INFN and CERN. The behavior of the fully equipped cavity substantially confirmed the results of the preliminary production tests in the vertical Cryostat. The quality factor at low field was substantially unchanged. No MP activity was detected confirming the soundness of the design and the quality of the surface treatment. (author)

From neutrino physics to beam polarisation. A high precision story at the ILC

International Nuclear Information System (INIS)

Vormwald, Benedikt

2014-03-01

In this thesis, we investigate the experimental prospects of studying a supersymmetric model with bilinearly broken R parity at the International Linear Collider. In this model, neutrinos mix with the supersymmetric neutralinos such that neutrino properties can be probed by examining neutralino decays, which incorporate usually a lepton and a W/Z boson. As a study case, we focus on the determination of the atmospheric neutrino mixing angle θ 23 , which is accessible via the ratio of the neutralino branching ratios BR(χ 0 1 →Wμ)/BR(χ 0 1 →Wτ). A detailed simulation of the International Large Detector has been performed for all Standard Model backgrounds and for χ 0 1 -pair production within a simplified model. The study is based on ILC beam parameters according to the Technical Design Report for a center-of-mass energy of √(s)=500 GeV. From muonic χ 0 1 decays, we find that the χ 0 1 mass can be reconstructed with an uncertainty of δ(m χ 0 1 )=(40(stat.)+35(syst.)) MeV for an integrated luminosity of ∫Ldt=500 fb -1 . The ratio of branching ratios can be determined to a precision of δ(BR(χ 0 1 →Wμ)/BR(χ 0 1 →Wτ))=2.9%. Due to this, the atmospheric neutrino mixing angle can be deduced with a precision comparable to modern neutrino experiments. Thus, the ILC is capable to test whether bRPV SUSY is the mechanism of neutrino mass generation. As also shown in the bRPV SUSY study of this thesis, beam polarisation is an important parameter in physics analyses at the ILC. The beam polarisation is measured with two Compton polarimeters per electron/positron beam. In order to achieve the design goal of an envisaged precision of 0.25%, the detector nonlinearity of the used Cherenkov detectors has to be determined very precisely. Herein, the main source of nonlinearity is expected to originate from the involved photomultipliers. For this reason, a differential nonlinearity measurement as well as a linearisation method is developed. The working

The short circumference damping ring design for the ILC

CERN Document Server

Korostelev, Maxim S; Kuriki, Masao; Kuroda, Shigeru; Naito, Takashi; Ross, Marc; Urakawa, Junji; Zimmermann, Frank

2005-01-01

The ILC damping ring tentative design is driven by the operational scenario of the main linac, the beam-dynamics demand of producing a stable and high-quality beam, the injection/extraction scheme and the kicker performance. In this paper, a short circumference damping ring design based on TME cells is described. The ring accommodates injection kickers which provide a flat top of 280 nsec and a 60 nsec rise and fall time and very fast strip-line kickers for beam extraction with a 2 nsec rise and fall time for 3-MHz operation. The potential impact of collective effects and the possible degradation of the dynamic aperture by nonlinear-wiggler fields are estimated.

Numerical study of free convection in an enclosure with two vertical isothermal walls

International Nuclear Information System (INIS)

Barletta, A.; Rossi di Schio, E.; Zanchini, E.; Nobile, E.; Pinto, F.

2005-01-01

In this paper, natural convection is studied in a 2D-cavity with two vertical isothermal walls, kept at different temperatures, and two adiabatic walls which are either straight (rectangular cavity) or elliptic (modified rectangular cavity). The local mass, momentum and energy balance equations are written in a dimensionless form and solved numerically, by means of two different software packages based on Galerkin finite element methods. With reference to a Prandtl number of 0.71, two rectangular cavities are studied: a square one and a cavity with height double than width. Then, for each value of the ratio between height and width, two cavities with elliptic boundaries are investigated. The numerical solution shows that the elliptic boundaries enhance the mean Nusselt number and the dimensionless mean kinetic energy of the fluid. (authors)

Higgs CP properties using the τ decay modes at the ILC

OpenAIRE

Berge, Stefan; Bernreuther, Werner; Spiesberger, Hubert

2013-01-01

We investigate the prospects of determining the CP nature of the 126 GeV neutral spin-0 (Higgs) boson h, discovered at the LHC, at a future linear e+e− collider (ILC). We consider the production of h by the Higgsstrahlung process e+e−→Z+h and its subsequent decays to τ leptons, h→τ−τ+. We investigate how precisely a possible pseudoscalar component of h can be detected by the measurement of a suitably defined angular distribution, if all major decay modes of the τ lepton are used. From our num...

Hydroforming SRF Three-cell Cavity from Seamless Niobium Tube

Energy Technology Data Exchange (ETDEWEB)

Yamanaka, Masashi [KEK, Tsukuba; Dohmae, Takeshi [KEK, Tsukuba; Hocker, Andy [Fermilab; Inoue, Hitoshi [KEK, Tsukuba; Park, Gunn-Tae [KEK, Tsukuba; Tajima, Tsuyoshi [Los Alamos; Umemori, Kensei [KEK, Tsukuba

2016-06-01

We are developing the manufacturing method for superconducting radio frequency (SRF) cavities by using a hydroforming instead of using conventional electron beam welding. We expect higher reliability and reduced cost with hydroforming. For successful hydroforming, high-purity seamless niobium tubes with good formability as well as advancing the hydroforming technique are necessary. Using a seamless niobium tube from ATI Wah Chang, we were able to successfully hydroform a 1.3 GHz three-cell TESLA-like cavity and obtained an Eacc of 32 MV/m. A barrel polishing process was omitted after the hydroforming. The vertical test was carried out with very rough inside surface. We got amazing and interesting result.

Lead salt resonant cavity enhanced detector with MEMS mirror

Science.gov (United States)

Felder, F.; Fill, M.; Rahim, M.; Zogg, H.; Quack, N.; Blunier, S.; Dual, J.

2010-01-01

We describe a tunable resonant cavity enhanced detector (RCED) for the mid-infrared employing narrow gap lead-chalcogenide (IV-VI) layers on a Si substrate. The device consists of an epitaxial Bragg reflector layer, a thin p-n+ heterojunction with PbSrTe as detecting layer and a micro-electro-mechanical system (MEMS) micromirror as second mirror. Despite the thin absorber layer the sensitivity is even higher than for a conventional detector. Tunability is achieved by changing the cavity length with a vertically movable MEMS mirror. The device may be used as miniature infrared spectrometer to cover the spectral range from 30 μm.

The quest for high-gradient superconducting cavities

International Nuclear Information System (INIS)

Padamsee, H.

1999-01-01

Superconducting RF cavities excel in applications requiring continuous waves or long pulse voltages. Since power losses in the walls of the cavity increase as the square of the accelerating voltage, copper cavities become uneconomical as demand for high continuous wave voltage grows with particle energy. For these reasons, RF superconductivity has become an important technology for high energy and high luminosity accelerators. The state of art in performance of sheet metal niobium cavities is best represented by the statistics of more than 300 5-cell, 1.5-GHz cavities built for CEBAF. Key aspects responsible for the outstanding performance of the CEBAF cavities set are the anti-multipactor, elliptical cell shape, good fabrication and welding techniques, high thermal conductivity niobium, and clean surface preparation. On average, field emission starts at the electric field of 8.7 MV/m, but there is a large spread, even though the cavities received nominally the same surface treatment and assembly procedures. In some cavities, field emission was detected as low as 3 MV/m. In others, it was found to be as high as 19 MV/m. As we will discuss, the reason for the large spread in the gradients is the large spread in emitter characteristics and the random occurrence of emitters on the surface. One important phenomenon that limits the achievable RF magnetic field is thermal breakdown of superconductivity, originating at sub-millimeter-size regions of high RF loss, called defects. Simulation reveal that if the defect is a normal conducting region of 200 mm radius, it will break down at 5 MV/m. Producing high gradients and high Q in superconducting cavities demands excellent control of material properties and surface cleanliness. The spread in gradients that arises from the random occurrence of defects and emitters must be reduced. It will be important to improve installation procedures to preserve the excellent gradients now obtained in laboratory test in vertical cryostats

A Novel Manufacturing Process for Compact, Low-Weight and Flexible Ultra-Wideband Cavity Backed Textile Antennas

Directory of Open Access Journals (Sweden)

Dries Van Baelen

2018-01-01

Full Text Available A novel manufacturing procedure for the fabrication of ultra-wideband cavity-backed substrate integrated waveguide antennas on textile substrates is proposed. The antenna cavity is constructed using a single laser-cut electrotextile patch, which is folded around the substrate. Electrotextile slabs protruding from the laser-cut patch are then vertically folded and glued to form the antenna cavity instead of rigid metal tubelets to implement the vertical cavity walls. This approach drastically improves mechanical flexibility, decreases the antenna weight to slightly more than 1 g and significantly reduces alignment errors. As a proof of concept, a cavity-backed substrate integrated waveguide antenna is designed and realized for ultra-wideband operation in the [5.15–5.85] GHz band. Antenna performance is validated in free space as well as in two on body measurement scenarios. Furthermore, the antenna’s figures of merit are characterized when the prototype is bent at different curvature radii, as commonly encountered during deployment on the human body. Also the effect of humidity content on antenna performance is studied. In all scenarios, the realized antenna covers the entire operating frequency band, meanwhile retaining a stable radiation pattern with a broadside gain above 5 dBi, and a radiation efficiency of at least 70%.

Numerical Studies on Natural Convection Heat Losses from Open Cubical Cavities

Directory of Open Access Journals (Sweden)

M. Prakash

2013-01-01

Full Text Available The natural convection heat losses occurring from cubical open cavities are analysed in this paper. Open cubical cavities of sides 0.1 m, 0.2 m, 0.25 m, 0.5 m, and 1 m with constant temperature back wall boundary conditions and opening ratio of 1 are studied. The Fluent CFD software is used to analyse the three-dimensional (3D cavity models. The studies are carried out for cavities with back wall temperatures between 35°C and 100°C. The effect of cavity inclination on the convective loss is analysed for angles of 0° (cavity facing sideways, 30°, 45°, 60°, and 90° (cavity facing vertically downwards. The Rayleigh numbers involved in this study range between 4.5 × 105 and 1.5 × 109. The natural convection loss is found to increase with an increase in back wall temperature. The natural convection loss is observed to decrease with an increase in cavity inclination; the highest convective loss being at 0° and the lowest at 90° inclination. This is observed for all cavities analysed here. Nusselt number correlations involving the effect of Rayleigh number and the cavity inclination angle have been developed from the current studies. These correlations can be used for engineering applications such as electronic cooling, low- and medium-temperature solar thermal systems, passive architecture, and also refrigeration systems.

Study of superconducting cavities for high power proton accelerators

International Nuclear Information System (INIS)

Biarrotte, J.L.

2000-01-01

The research program on hybrid reactors has started in France in order to study the technologies allowing the transmutation of radioactive wastes thanks to a spallation neutron source supplied by a linear high intensity proton accelerator. The study of the high energy part of this accelerator (superconducting accelerator for hybrid) has started, and its aim is the design of superconducting radiofrequency cavities which make the two different sections of the accelerator (0.47 and 0.65). This thesis presents the advance of the work carried out on this topic since 1997, in particular the design and optimization of the 5-cell cavities which work at the 704.4 MHz frequency. The experimental part of the study has been carried out in parallel with the industrial fabrication (Cerca) of several prototypes of mono-cell cavities. These cavities have shown very good RF performances during the tests in vertical cryostat; the A 102 A cavity, in particular develops a Q0 of 7.10 10 (indicating very low RF losses) and reaches an accelerator field of 25 MV/m, i.e. more than two times the specified value (about 10 MV/V). Finally, a new risk analysis method for the excitation of the upper modes is proposed. This method shows in particular the uselessness of the implementation of HOM couplers on the cavities for a continuous beam use. (J.S.)

Design of a current based readout chip and development of a DEPFET pixel prototype system for the ILC vertex detector

International Nuclear Information System (INIS)

Trimpl, M.

2005-12-01

The future TeV-scale linear collider ILC (International Linear Collider) offers a large variety of precision measurements complementary to the discovery potential of the LHC (Large Hadron Collider). To fully exploit its physics potential, a vertex detector with unprecedented performance is needed. One proposed technology for the ILC vertex detector is the DEPFET active pixel sensor. The DEPFET sensor offers particle detection with in-pixel amplification by incorporating a field effect transistor into a fully depleted high-ohmic silicon substrate. The device provides an excellent signal-to-noise ratio and a good spatial resolution at the same time. To establish a very fast readout of a DEPFET pixel matrix with row rates of 20 MHz and more, the 128 channel CURO II ASIC has been designed and fabricated. The architecture of the chip is completely based on current mode techniques (SI) perfectly adapted to the current signal of the sensor. For the ILC vertex detector a prototype system with a 64 x 128 DEPFET pixel matrix read out by the CURO II chip has been developed. The design issues and the standalone performance of the readout chip as well as first results with the prototype system will be presented. (orig.)

Design of a current based readout chip and development of a DEPFET pixel prototype system for the ILC vertex detector

Energy Technology Data Exchange (ETDEWEB)

Trimpl, M.

2005-12-15

The future TeV-scale linear collider ILC (International Linear Collider) offers a large variety of precision measurements complementary to the discovery potential of the LHC (Large Hadron Collider). To fully exploit its physics potential, a vertex detector with unprecedented performance is needed. One proposed technology for the ILC vertex detector is the DEPFET active pixel sensor. The DEPFET sensor offers particle detection with in-pixel amplification by incorporating a field effect transistor into a fully depleted high-ohmic silicon substrate. The device provides an excellent signal-to-noise ratio and a good spatial resolution at the same time. To establish a very fast readout of a DEPFET pixel matrix with row rates of 20 MHz and more, the 128 channel CURO II ASIC has been designed and fabricated. The architecture of the chip is completely based on current mode techniques (SI) perfectly adapted to the current signal of the sensor. For the ILC vertex detector a prototype system with a 64 x 128 DEPFET pixel matrix read out by the CURO II chip has been developed. The design issues and the standalone performance of the readout chip as well as first results with the prototype system will be presented. (orig.)

Light higgsinos at the ILC. Precision measurements and detector requirements

International Nuclear Information System (INIS)

Sert, Hale

2016-01-01

This thesis is based on a study of Natural Supersymmetry (SUSY) scenarios at the International Linear Collider (ILC). These scenarios are motivated by naturalness, which requires the mu parameter to be at the electroweak scale. The considered Natural SUSY scenario contains three light higgsino-like charginos and neutralinos, χ 1 ± , χ 1 0 and χ 2 0 with a mass splitting of a few GeV or even sub-GeV, while all other supersymmetric particles are heavy in the multi-TeV scale. Due to the small mass difference of a few GeV, the final state consists of a large missing energy and a few very soft visible particles. Therefore, the analysis of such scenarios is extremely challenging for the LHC as well as the ILC. In order to investigate the feasibility of observing light higgsinos at the ILC, an analysis has been performed using both fast detector simulation and full detector simulation for International Large Detector (ILD). The fast simulation results have indicated that the key observables of the higgsinos can be reconstructed with an uncertainty of a few percent. It has been shown that the results enable determining the lower limits and allowed regions for the mass parameters of the bino M 1 and the wino M 2 , as well as determining the higgsino mass parameter μ to the accuracy of a few percent. The full simulation analysis has provided information about detector requirements, such as the identification of low momentum electrons and muons. The electron identification can be studied by using the ionisation energy loss of the particles per length, dE/dx, which can be obtained from the Time Projection Chamber (TPC) of ILD. The identification of low momentum muons has been studied in the context of the thesis by using the calorimeter cluster shape differences between muons and pions. As a result, a method has been developed for particles with momentum lower than 2 GeV, and its impact on the higgsino analysis has been investigated. It has been found that assuming the

From neutrino physics to beam polarisation. A high precision story at the ILC

Energy Technology Data Exchange (ETDEWEB)

Vormwald, Benedikt

2014-03-15

In this thesis, we investigate the experimental prospects of studying a supersymmetric model with bilinearly broken R parity at the International Linear Collider. In this model, neutrinos mix with the supersymmetric neutralinos such that neutrino properties can be probed by examining neutralino decays, which incorporate usually a lepton and a W/Z boson. As a study case, we focus on the determination of the atmospheric neutrino mixing angle θ{sub 23}, which is accessible via the ratio of the neutralino branching ratios BR(χ{sup 0}{sub 1}→Wμ)/BR(χ{sup 0}{sub 1}→Wτ). A detailed simulation of the International Large Detector has been performed for all Standard Model backgrounds and for χ{sup 0}{sub 1}-pair production within a simplified model. The study is based on ILC beam parameters according to the Technical Design Report for a center-of-mass energy of √(s)=500 GeV. From muonic χ{sup 0}{sub 1} decays, we find that the χ{sup 0}{sub 1} mass can be reconstructed with an uncertainty of δ(m{sub χ{sup 0}{sub 1}})=(40(stat.)+35(syst.)) MeV for an integrated luminosity of ∫Ldt=500 fb{sup -1}. The ratio of branching ratios can be determined to a precision of δ(BR(χ{sup 0}{sub 1}→Wμ)/BR(χ{sup 0}{sub 1}→Wτ))=2.9%. Due to this, the atmospheric neutrino mixing angle can be deduced with a precision comparable to modern neutrino experiments. Thus, the ILC is capable to test whether bRPV SUSY is the mechanism of neutrino mass generation. As also shown in the bRPV SUSY study of this thesis, beam polarisation is an important parameter in physics analyses at the ILC. The beam polarisation is measured with two Compton polarimeters per electron/positron beam. In order to achieve the design goal of an envisaged precision of 0.25%, the detector nonlinearity of the used Cherenkov detectors has to be determined very precisely. Herein, the main source of nonlinearity is expected to originate from the involved photomultipliers. For this reason, a differential

Experimental investigation of the charge/discharge process for an organic PCM macroencapsulated in an aluminium rectangular cavity

Science.gov (United States)

Bejan, Andrei-Stelian; Labihi, Abdelouhab; Croitoru, Cristiana Verona; Catalina, Tiberiu; Chehouani, Hassan; Benhamou, Brahim

2018-02-01

Buildings sector has one of the highest potential regarding the reduction of greenhouse gases emissions, as being responsible for more than 40% of energy consumption worldwide. This is why, in order to achieve indoor thermal comfort, it is mandatory to use energy-efficient systems. Materials acting as thermal energy storage (TES) represents one of the most effective strategy that can be implemented and nowadays, many studies are focusing their attention on latent heat storage, respectively on phase changing materials (PCM) which can embed a large embed a high quantity of energy, unlike classic materials acting as thermal mass. This purpose of this paper is to experimentally investigate the charge and discharge processes for an organic PCM (RT35 paraffin) macroencapsulated in an aluminium rectangular cavity which was placed first in a horizontal position and after in a vertical position. After several experimental campaigns conducted we determined that the vertical position enhance the heat transfer because of the natural convection which occurs inside the cavity. Therefore, the charging time is lower in case of the vertical cavity and the temperature measured inside and on the surface is higher.

Searching for the doubly charged scalars in the Georgi-Machacek model via γγ collisions at the ILC

Science.gov (United States)

Cao, Jun; Li, Yu-Qi; Liu, Yao-Bei

2018-04-01

The Georgi-Machacek (GM) model predicts the existence of the doubly-charged scalars H5±±, which can be seen the typical particles in this model and their diboson decay channels are one of the most promising ways to discover such new doubly-charged scalars. Based on the constraints of the latest combined ATLAS and CMS Higgs boson diphoton signal strength data at 2σ confidence level, we focus on the study of the triple scalar production in γγ collisions at the future International Linear collider (ILC): γγ → hH5++H 5‑‑, where the production cross-sections are very sensitive to the triple scalar coupling parameter ghHH. Considering the typical same-sign diboson decay modes for the doubly-charged scalars, the possible final signals might be detected via this process at the future ILC experiments.

Transverse jet-cavity interactions with the influence of an impinging shock

International Nuclear Information System (INIS)

Zare-Behtash, H.; Lo, K.H.; Kontis, K.; Ukai, T.; Obayashi, S.

2015-01-01

Highlights: • Experimental study of shock-jet-cavity in a supersonic freestream is conducted. • Shock impingement at the cavity leading edge lifts the shear layer, encouraging momentum transfer. • Shock impingement close to the jet location increases the number of smaller turbulent structures. - Abstract: For high-speed air breathing engines, fuel injection and subsequent mixing with air is paramount for combustion. The high freestream velocity poses a great challenge to efficient mixing both in macroscale and microscale. Utilising cavities downstream of fuel injection locations, as a means to hold the flow and stabilise the combustion, is one mechanism which has attracted much attention, requiring further research to study the unsteady flow features and interactions occurring within the cavity. In this study we combine the transverse jet injection upstream of a cavity with an impinging shock to see how this interaction influences the cavity flow, since impinging shocks have been shown to enhance mixing of transverse jets. Utilising qualitative and quantitative methods: schlieren, oilflow, PIV, and PSP the induced flowfield is analysed. The impinging shock lifts the shear layer over the cavity and combined with the instabilities generated by the transverse jet creates a highly complicated flowfield with numerous vertical structures. The interaction between the oblique shock and the jet leads to a relatively uniform velocity distribution within the cavity

Beam Acceleration by a Multicell RF Cavity Structure Proposed for an Improved Yield in Hydroforming

International Nuclear Information System (INIS)

Kang, Yoon W.; Shin, Ki; Fathy, A.E.; Holmes, Jeffrey A.

2012-01-01

We study the accelerating properties of a new multicell cavity structure with irises forming a rectangular aperture between the cavity cells. We are interested in this structure because, from a mechanical point of view, it may be possible to manufacture with high quality using a hydroforming process. RF analysis shows that the rectangular iris shape provides some asymmetric transverse focusing per half RF period, particularly for low beam energies. If the horizontal and vertical rectangular irises are interleaved, the net transverse focusing could be increased. Here we present studies of the acceleration and transport properties of these cavities by tracking particles using the ORBIT Code through time-dependent 3D cavity fields taken from CST MWS.

SPIROC (SiPM Integrated Read-Out Chip) Dedicated very front-end electronics for an ILC prototype hadronic calorimeter with SiPM read-out

CERN Document Server

Bouchel, Michel; Dulucq, Frédéric; Fleury, Julien; de La Taille, Christophe; Martin-Chassard, Gisèle; Raux, Ludovic

2009-01-01

The SPIROC chip is a dedicated very front-end electronics for an ILC prototype hadronic calorimeter with Silicon photomultiplier (or MPPC) readout. This ASIC is due to equip a 10,000-channel demonstrator in 2009. SPIROC is an evolution of FLC_SiPM used for the ILC AHCAL physics prototype [1]. SPIROC was submitted in June 2007 and will be tested in September 2007. It embeds cutting edge features that fulfil ILC final detector requirements. It has been realized in 0.35m SiGe technology. It has been developed to match the requirements of large dynamic range, low noise, low consumption, high precision and large number of readout channels needed. SPIROC is an auto-triggered, bi-gain, 36-channel ASIC which allows to measure on each channel the charge from one photoelectron to 2000 and the time with a 100ps accurate TDC. An analogue memory array with a depth of 16 for each channel is used to store the time information and the charge measurement. A 12-bit Wilkinson ADC has been embedded to digitize the analogue memor...

SPIROC (SiPM Integrated Read-Out Chip) Dedicated very front-end electronics for an ILC prototype hadronic calorimeter with SiPM read-out

CERN Document Server

Bouchel, Michel; Fleury, Julien; de La Taille, Christophe; Martin-Chassard, Gisèle; Raux, Ludovic

2007-01-01

The SPIROC chip is a dedicated very front-end electronics for an ILC prototype hadronic calorimeter with Silicon photomultiplier (or MPPC) readout. This ASIC is due to equip a 10,000-channel demonstrator in 2009. SPIROC is an evolution of FLC_SiPM used for the ILC AHCAL physics prototype [1]. SPIROC was submitted in June 2007 and will be tested in September 2007. It embeds cutting edge features that fulfil ILC final detector requirements. It has been realized in 0.35m SiGe technology. It has been developed to match the requirements of large dynamic range, low noise, low consumption, high precision and large number of readout channels needed. SPIROC is an auto-triggered, bi-gain, 36-channel ASIC which allows to measure on each channel the charge from one photoelectron to 2000 and the time with a 100ps accurate TDC. An analogue memory array with a depth of 16 for each channel is used to store the time information and the charge measurement. A 12-bit Wilkinson ADC has been embedded to digitize the analogue memor...

Beam Collimation Studies for the ILC Positron Source

Energy Technology Data Exchange (ETDEWEB)

Drozhdin, A.; /Fermilab; Nosochkov, Y.; Zhou, F.; /SLAC

2008-06-26

Results of the collimation studies for the ILC positron source beam line are presented. The calculations of primary positron beam loss are done using the ELEGANT code. The secondary positron and electron beam loss, the synchrotron radiation along the beam line and the bremsstrahlung radiation in the collimators are simulated using the STRUCT code. The first part of the collimation system, located right after the positron source target (0.125 GeV), is used for protection of the RF Linac sections from heating and radiation. The second part of the system is used for final collimation before the beam injection into the Damping Ring at 5 GeV. The calculated power loss in the collimation region is within 100 W/m, with the loss in the collimators of 0.2-5 kW. The beam transfer efficiency from the target to the Damping Ring is 13.5%.

Multi-Bunch Simulations of the ILC for Luminosity Performance Studies

CERN Document Server

White, Glen; Walker, Nicholas J

2005-01-01

To study the luminosity performance of the International Linear Collider (ILC) with different design parameters, a simulation was constructed that tracks a multi-bunch representation of the beam from the Damping Ring extraction through to the Interaction Point. The simulation code PLACET is used to simulate the LINAC, MatMerlin is used to track through the Beam Delivery System and GUINEA-PIG for the beam-beam interaction. Included in the simulation are ground motion and wakefield effects, intra-train fast feedback and luminosity-based feedback systems. To efficiently study multiple parameters/multiple seeds, the simulation is deployed on the Queen Mary High-Throughput computing cluster at Queen Mary, University of London, where 100 simultaneous simulation seeds can be run.

Beam polarization at the ILC. The physics impact and the accelerator solutions

Energy Technology Data Exchange (ETDEWEB)

Aurand, B. [Bonn Univ. (Germany). Phys. Inst.; Bailey, I. [Liverpool Univ. (United Kingdom). Cockcroft Inst.; Bartels, C. [DESY, Hamburg (Germany); DESY, Zeuthen (DE)] (and others)

2009-03-15

In this contribution accelerator solutions for polarized beams and their impact on physics measurements are discussed. Focus are physics requirements for precision polarimetry near the interaction point and their realization with polarized sources. Based on the ILC baseline programme as described in the Reference Design Report (RDR), recent developments are discussed and evaluated taking into account physics runs at beam energies between 100 GeV and 250 GeV, as well as calibration runs on the Z-pole and options as the 1 TeV upgrade and GigaZ. (orig.)

Multi-angle VECSEL cavities for dispersion control and multi-color operation

Science.gov (United States)

Baker, Caleb; Scheller, Maik; Laurain, Alexandre; Yang, Hwang-Jye; Ruiz Perez, Antje; Stolz, Wolfgang; Addamane, Sadhvikas J.; Balakrishnan, Ganesh; Jones, R. Jason; Moloney, Jerome V.

2017-02-01

We present a novel Vertical External Cavity Surface Emitting Laser (VECSEL) cavity design which makes use of multiple interactions with the gain region under different angles of incidence in a single round trip. This design allows for optimization of the net, round-trip Group Delay Dispersion (GDD) by shifting the GDD of the gain via cavity fold angle while still maintaining the high gain of resonant structures. The effectiveness of this scheme is demonstrated with femtosecond-regime pulses from a resonant structure and record pulse energies for the VECSEL gain medium. In addition, we show that the interference pattern of the intracavity mode within the active region, resulting from the double-angle multifold, is advantageous for operating the laser in CW on multiple wavelengths simultaneously. Power, noise, and mode competition characterization is presented.

CFD Simulation of Flow Tones from Grazing Flow past a Deep Cavity

International Nuclear Information System (INIS)

T Bagwell

2006-01-01

Locked-in flow tones due to shear flow over a deep cavity are investigated using Large Eddy Simulation (LES). An isentropic form of the compressible Navier-Stokes equations (pseudo-compressibility) is used to couple the vertical flow over the cavity mouth with the deep cavity resonances (1). Comparisons to published experimental data (2) show that the pseudo-compressible LES formulation is capable of predicting the feedforward excitation of the deep cavity resonator, as well as the feedback process from the resonator to the flow source. By systematically increasing the resonator damping level, it is shown that strong lock-in results in a more organized shear layer than is observed for the locked-out flow state. By comparison, weak interactions (non-locked-in) produce no change in the shear layer characteristics. This supports the 40 dB definition of lock-in defined in the experiment

Scalar production in association with a Z boson at the LHC and ILC: The mixed Higgs-radion case of warped models

Science.gov (United States)

Angelescu, Andrei; Moreau, Grégory; Richard, François

2017-07-01

The radion scalar field might be the lightest new particle predicted by extradimensional extensions of the standard model. It could thus lead to the first signatures of new physics at the LHC collider. We perform a complete study of the radion production in association with the Z gauge boson in the custodially protected warped model with a brane-localized Higgs boson addressing the gauge hierarchy problem. Radion-Higgs mixing effects are present. Such a radion production receives possibly resonant contributions from the Kaluza-Klein excitations of the Z boson as well as the extra neutral gauge boson (Z'). All the exchange and mixing effects induced by those heavy bosons are taken into account in the radion coupling and rate calculations. The investigation of the considered radion production at the LHC allows us to be sensitive to some parts of the parameter space but only the ILC program at high luminosity would cover most of the theoretically allowed parameter space via the studied reaction. Complementary tests of the same theoretical parameters can be realized through the high accuracy measurements of the Higgs couplings at the ILC. The generic sensitivity limits on the rates discussed for the LHC and ILC potential reach can be applied to the searches for other (light) exotic scalar bosons.

Fabrication and vertical test experience of the European X-ray Free Electron Laser 3.9 GHz superconducting cavities

Science.gov (United States)

Pierini, P.; Bertucci, M.; Bosotti, A.; Chen, J. F.; Maiano, C. G.; Michelato, P.; Monaco, L.; Moretti, M.; Pagani, C.; Paparella, R.; Sertore, D.; Vogel, E.

2017-04-01

We report the experience of the production, processing and qualification testing of the superconducting radio frequency cavities at 3.9 GHz for the third harmonic system at the European XFEL (EXFEL) injector. The rf structure concept, originally developed for the FLASH FEL facility, was adapted to the new interfaces provided by the EXFEL design and the cavities were procured from a qualified vendor, delivered ready for the testing at the INFN infrastructure. A total of 23 cavities, three prototypes and two batches of 10, have been realized and tested up to specifications.

Different optical properties in different periodic slot cavity geometrical morphologies

Science.gov (United States)

Zhou, Jing; Shen, Meng; Du, Lan; Deng, Caisong; Ni, Haibin; Wang, Ming

2016-09-01

In this paper, optical properties of two-dimensional periodic annular slot cavity arrays in hexagonal close-packing on a silica substrate are theoretically characterized by finite difference time domain (FDTD) simulation method. By simulating reflectance spectra, electric field distribution, and charge distribution, we confirm that multiple cylindrical surface plasmon resonances can be excited in annular inclined slot cavities by linearly polarized light, in which the four reflectance dips are attributed to Fabry-Perot cavity resonances in the coaxial cavity. A coaxial waveguide mode TE11 will exist in these annular cavities, and the wavelengths of these reflectance dips are effectively tailored by changing the geometrical pattern of slot cavity and the dielectric materials filled in the cavities. These resonant wavelengths are localized in annular cavities with large electric field enhancement and dissipate gradually due to metal loss. The formation of an absorption peak can be explained from the aspect of phase matching conditions. We observed that the proposed structure can be tuned over the broad spectral range of 600-4000 nm by changing the outer and inner radii of the annular gaps, gap surface topography. Meanwhile, different lengths of the cavity may cause the shift of resonance dips. Also, we study the field enhancement at different vertical locations of the slit. In addition, dielectric materials filling in the annular gaps will result in a shift of the resonance wavelengths, which make the annular cavities good candidates for refractive index sensors. The refractive index sensitivity of annular cavities can also be tuned by the geometry size and the media around the cavity. Annular cavities with novel applications can be implied as surface enhanced Raman spectra substrates, refractive index sensors, nano-lasers, and optical trappers. Project supported by the National Natural Science Foundation of China (Grant No. 61178044), the Natural Science Foundation

Deep drawing experiences of niobium disk for PEFP SRF cavity prototype

International Nuclear Information System (INIS)

Kim, Han Sung; An, Sun; Zhang, Liping; Tang, Yazhe; Li, Ying Min; Kwon, Hyeok Jung; Cho, Yong Sub

2009-01-01

A superconducting radio frequency (SRF) cavity with a geometrical beta of 0.42 has been designed to accelerate a proton beam after 100 MeV for an extension of Proton Engineering Frontier Project (PEFP). The designed cavity shape is an elliptical and the resonant frequency is 700 MHz. In order to confirm the RF and mechanical properties of the cavity, two prototypes of copper cavities have been fabricated and tested. Based on the experiences gained with the copper prototypes, two niobium prototypes have been designed. One is two-cell cavity and the other is five cell cavity. The two-cell cavity is for finalizing the niobium cavity production procedure and testing the cavity RF properties at a low temperature and moderate power level. The five-cell cavity is for checking the production quality and testing vertical test system in the future. Both of them are under fabrication. Through the fabrication of the niobium prototype, several issues such as deep drawing, electron beam welding and surface treatment will be addressed. The drawing of the PEPF SRF low beta cavity is shown in Fig. 1. Major parameters for the cavity are like following. - Frequency: 700 MHz - Operating mode: TM010 pi mode - Cavity type: Elliptical - Geometrical beta: 0.42 - Number of cells: 5 per cavity - Accelerating gradient: 8 MV/m - Epeak/Eacc: 3.71 - Bpeak/Eacc: 7.47 mT/(MV/m) - R/Q: 102.3 ohm - Epeak: 29.68 MV/m - Field flatness: 1.56 % - Cell to cell coupling: 1.41 % - Geometrical factor: 121.68 ohm - Cavity wall thickness: 4.3 mm - Lorentz force detuning: 0.4 Hz/(MV/m)2 - Stiffening structure: Double ring - Effective length: 0.45 m - External Q of FPC: 8.0E5 ±20 % - HOM load: less than 2 W - HOM Qext requirement: less than 3.0E5 At present, all the niobium disk and plates for cavity and NbTi flanges for beam pipe flange are prepared

Measuring hadronic jets at the ILC. From particle flow calorimetry to the Higgs self-coupling

International Nuclear Information System (INIS)

Hermberg, Benjamin

2015-10-01

This work deals with the development of a technical prototype of a highly segmented hadron calorimeter for precision measurements at the future International Linear Collider (ILC). The precision measurements at the ILC pose special challenges for both the detector technology as well as for the reconstruction methods. In this thesis two aspects to hadronic final states are examined. The first part deals with a prototype of a highly segmented hadronic calorimeter and the second part with kinematic Fits for the determination of the Higgs self-coupling in decays of the Higgs boson into b quarks. The challenge for the examined prototype of the hadronic calorimeter is the demonstration of the technical feasibility of a real detector. The ILC is pursuing the Particle Flow concept, as a consequence, it follows for the calorimeter a high granularity and an integrated readout electronics. Two important aspects of the calorimeter prototype are the channel-wise adjustable trigger threshold and the power-pulsing functionality to minimize the power consumption. In this work it could be shown that with the current readout chip generation, the use of the channel-wise threshold adjustment leads to a shift of the global trigger threshold. Despite of the functionality of the power pulsing, the total current consumption is 30 times above the desired power consumption of 25 μW/channel. In the data of a test beam campaign at CERN 2012 the pedestal was determined, the stability analyzed and specific features of the pedestal identified. In order to achieve the accuracy for the measurement of the Higgs self-coupling, this work examines the applicability of kinematic fits within the framework of the Higgs self-coupling analysis. Basis of the analysis is the lepton channel ZHH→l anti lb anti bb anti b.It could be shown that the use of kinematic fits improves the mass resolution, thus the uncertainty of the cross section is reduced by 18%. The use of a modified fit processor improves the

Continuous wave vertical cavity surface emitting lasers at 2.5 μm with InP-based type-II quantum wells

International Nuclear Information System (INIS)

Sprengel, S.; Andrejew, A.; Federer, F.; Veerabathran, G. K.; Boehm, G.; Amann, M.-C.

2015-01-01

A concept for electrically pumped vertical cavity surface emitting lasers (VCSEL) for emission wavelength beyond 2 μm is presented. This concept integrates type-II quantum wells into InP-based VCSELs with a buried tunnel junction as current aperture. The W-shaped quantum wells are based on the type-II band alignment between GaInAs and GaAsSb. The structure includes an epitaxial GaInAs/InP and an amorphous AlF 3 /ZnS distributed Bragg reflector as bottom and top (outcoupling) mirror, respectively. Continuous-wave operation up to 10 °C at a wavelength of 2.49 μm and a peak output power of 400 μW at −18 °C has been achieved. Single-mode emission with a side-mode suppression ratio of 30 dB for mesa diameters up to 14 μm is presented. The long emission wavelength and current tunability over a wavelength range of more than 5 nm combined with its single-mode operation makes this device ideally suited for spectroscopy applications

Reconstruction of IP Beam Parameters at the ILC from Beamstraahlung

CERN Document Server

White, Glen

2005-01-01

The luminosity performance of the ILC will be very sensitive to the parameters of the colliding bunches. Only some of these parameters can be measured using planned instrumentation. This analysis aims to access some of the colliding beam parameters not available by other means and to improve on the resolution of those that are. GUINEA-PIG is used to simulate the beam-beam interactions and produce beamstrahlung radiation (e+/e- pairs and photons). These are tracked to a simulation of the low-angle Beam Calorimeter and a photon detector and event shapes are produced. A Taylor map is produced to transform from the event shapes to the simulated beam parameters. This paper reports on the progress of this analysis, examining the usefulness of the proposed fitting technique.

Effect of Perpendicular Magnetic Field on Free Convection in a Rectangular Cavity

Directory of Open Access Journals (Sweden)

Anand Kumar

2015-12-01

Full Text Available The steady free convective flow of a viscous incompressible and electrically conducting fluid in a two-dimensional cavity in the presence of a magnetic field applied normal to the plane of the cavity is investigated. The side vertical walls of the cavity are heated differentially while the horizontal walls are assumed to be insulated. The governing equations are re-formulated in terms of vorticity and stream function. The resulting boundary value problem is solved numerically using an alternating direction implicit (ADI method. A number of plots illustrating the influence of Hartmann number and Rayleigh number on the streamlines and isotherms as well as the velocity and temperature profiles are shown. Furthermore, results for the average Nusselt number and the maximum absolute stream function have been obtained, and these are compared with the corresponding results in the literature when the magnetic field is applied along the cavity in the horizontal direction.

Improving the pair separation of WW/ZZ at the ILC by consideration of photon radiation in kinematic fits; Verbesserung der WW/ZZ-Unterscheidung am ILC durch Beruecksichtigung von Photonabstrahlung in kinematischen Fits

Energy Technology Data Exchange (ETDEWEB)

Beckmann, Moritz

2010-04-15

The International Linear Collider (ILC) is intended for high precision measurements. This places enormous demands on detector precision in the ongoing detector development program. Precision can be further improved by application of a kinematic fit to the data, forcing energy and momentum conservation. However, this requires all energies and momenta to be considered. Initial state radiation and beamstrahlung are two processes which emit photons predominantly in the beam direction and which escape detection. Due to higher center-of-mass energy and stronger focussing of the beam, these processes will have more impact at the ILC than at earlier colliders. This thesis investigates the effects of these processes on kinematic fits at the example of the separation of events with WW/ZZ pair production events. Different approaches in consideration of these processes are pointed out. A kinematic fit was performed on a sample of simulated e{sup +}e{sup -} {yields} u anti dd anti u events, forcing energy and momentum conservation and equal boson masses. It is shown that 25% more events can be covered in this fit, if photon radiation is taken into consideration using a basic approximation of the momentum spectrum of the photons. This method obtains even a further increase in resolution. Thus, a mass resolution of 1.9 GeV (without decay width) can be obtained. (orig.)

Characterisation and application of radiation hard sensors for LHC and ILC

International Nuclear Information System (INIS)

Novgorodova, Olga

2013-11-01

The Large Hadron Collider (LHC) currently in operation intends to explore particle physics on the TeV scale. The International Linear Collider (ILC) and the Compact Linear Collider (CLIC) are being designed to measure the properties of particles discovered at the LHC with higher precision. Very forward detector systems at these machines are needed for the precise measurement of the luminosity and to approach full polar angle overage. In the current detector concepts for linear collider two electromagnetic calorimeters, Beam Calorimeter (BeamCal) and Luminosity Calorimeter (LumiCal), are foreseen. Both calorimeters are designed as sandwich calorimeters with tungsten absorber layers instrumented with finely segmented sensors. Due to a large amount of beamstrahlung remnants hitting BeamCal at the innermost radii, the sensors must withstand up to 1 MGy radiation dose per year. In this thesis two types of sensor materials were investigated: single crystal chemical vapour deposition diamonds (scCVDD) and gallium arsenide doped by chromium (GaAs:Cr). The very forward calorimeters ensure coverage for high energy electrons, positrons and photons down to very low polar angles. Within this thesis, simulation studies are presented for different beam parameters of the ILC. A new sensor segmentation was proposed to achieve better reconstruction efficiency of single high-energy electrons, positrons and photons on top of the beamstrahlung background. Only for a few years ago polycrystalline diamond sensors have been used for beam diagnostics in high-energy physics experiments. The Compact Muon Solenoid experiment, CMS, at the LHC is instrumented with several detectors for the Beam Conditions and Radiation Monitoring. The Fast Beam Conditions Monitor (BCM1F) is part of these systems. Here for the first time single crystal diamond sensors have been used. Eight detectors, comprising each a single crystal sensor and front-end electronics, are positioned around the beam pipe on both

Characterisation and application of radiation hard sensors for LHC and ILC

Energy Technology Data Exchange (ETDEWEB)

Novgorodova, Olga

2013-11-15

The Large Hadron Collider (LHC) currently in operation intends to explore particle physics on the TeV scale. The International Linear Collider (ILC) and the Compact Linear Collider (CLIC) are being designed to measure the properties of particles discovered at the LHC with higher precision. Very forward detector systems at these machines are needed for the precise measurement of the luminosity and to approach full polar angle overage. In the current detector concepts for linear collider two electromagnetic calorimeters, Beam Calorimeter (BeamCal) and Luminosity Calorimeter (LumiCal), are foreseen. Both calorimeters are designed as sandwich calorimeters with tungsten absorber layers instrumented with finely segmented sensors. Due to a large amount of beamstrahlung remnants hitting BeamCal at the innermost radii, the sensors must withstand up to 1 MGy radiation dose per year. In this thesis two types of sensor materials were investigated: single crystal chemical vapour deposition diamonds (scCVDD) and gallium arsenide doped by chromium (GaAs:Cr). The very forward calorimeters ensure coverage for high energy electrons, positrons and photons down to very low polar angles. Within this thesis, simulation studies are presented for different beam parameters of the ILC. A new sensor segmentation was proposed to achieve better reconstruction efficiency of single high-energy electrons, positrons and photons on top of the beamstrahlung background. Only for a few years ago polycrystalline diamond sensors have been used for beam diagnostics in high-energy physics experiments. The Compact Muon Solenoid experiment, CMS, at the LHC is instrumented with several detectors for the Beam Conditions and Radiation Monitoring. The Fast Beam Conditions Monitor (BCM1F) is part of these systems. Here for the first time single crystal diamond sensors have been used. Eight detectors, comprising each a single crystal sensor and front-end electronics, are positioned around the beam pipe on both

Demonstration of a III-nitride vertical-cavity surface-emitting laser with a III-nitride tunnel junction intracavity contact

International Nuclear Information System (INIS)

Leonard, J. T.; Young, E. C.; Yonkee, B. P.; Cohen, D. A.; Margalith, T.; Speck, J. S.; DenBaars, S. P.; Nakamura, S.

2015-01-01

We report on a III-nitride vertical-cavity surface-emitting laser (VCSEL) with a III-nitride tunnel junction (TJ) intracavity contact. The violet nonpolar VCSEL employing the TJ is compared to an equivalent VCSEL with a tin-doped indium oxide (ITO) intracavity contact. The TJ VCSEL shows a threshold current density (J th ) of ∼3.5 kA/cm 2 , compared to the ITO VCSEL J th of 8 kA/cm 2 . The differential efficiency of the TJ VCSEL is also observed to be significantly higher than that of the ITO VCSEL, reaching a peak power of ∼550 μW, compared to ∼80 μW for the ITO VCSEL. Both VCSELs display filamentary lasing in the current aperture, which we believe to be predominantly a result of local variations in contact resistance, which may induce local variations in refractive index and free carrier absorption. Beyond the analyses of the lasing characteristics, we discuss the molecular-beam epitaxy (MBE) regrowth of the TJ, as well as its unexpected performance based on band-diagram simulations. Furthermore, we investigate the intrinsic advantages of using a TJ intracavity contact in a VCSEL using a 1D mode profile analysis to approximate the threshold modal gain and general loss contributions in the TJ and ITO VCSEL

Demonstration of a III-nitride vertical-cavity surface-emitting laser with a III-nitride tunnel junction intracavity contact

Energy Technology Data Exchange (ETDEWEB)

Leonard, J. T., E-mail: jtleona01@gmail.com; Young, E. C.; Yonkee, B. P.; Cohen, D. A.; Margalith, T.; Speck, J. S. [Materials Department, University of California, Santa Barbara, California 93106 (United States); DenBaars, S. P.; Nakamura, S. [Materials Department, University of California, Santa Barbara, California 93106 (United States); Department of Electrical and Computer Engineering, University of California, Santa Barbara, California 93106 (United States)

2015-08-31

We report on a III-nitride vertical-cavity surface-emitting laser (VCSEL) with a III-nitride tunnel junction (TJ) intracavity contact. The violet nonpolar VCSEL employing the TJ is compared to an equivalent VCSEL with a tin-doped indium oxide (ITO) intracavity contact. The TJ VCSEL shows a threshold current density (J{sub th}) of ∼3.5 kA/cm{sup 2}, compared to the ITO VCSEL J{sub th} of 8 kA/cm{sup 2}. The differential efficiency of the TJ VCSEL is also observed to be significantly higher than that of the ITO VCSEL, reaching a peak power of ∼550 μW, compared to ∼80 μW for the ITO VCSEL. Both VCSELs display filamentary lasing in the current aperture, which we believe to be predominantly a result of local variations in contact resistance, which may induce local variations in refractive index and free carrier absorption. Beyond the analyses of the lasing characteristics, we discuss the molecular-beam epitaxy (MBE) regrowth of the TJ, as well as its unexpected performance based on band-diagram simulations. Furthermore, we investigate the intrinsic advantages of using a TJ intracavity contact in a VCSEL using a 1D mode profile analysis to approximate the threshold modal gain and general loss contributions in the TJ and ITO VCSEL.

Associated production of a neutral top-Higgs with a heavy-quark pair in the γγ collisions at ILC

International Nuclear Information System (INIS)

Huang Jinshu; Lu Gongru; Xu Wei; Wang Shuaiwei

2010-01-01

We have studied the associated production processes of a neutral top-Higgs in the topcolor assisted technicolor model with a pair of heavy quarks in γγ collisions at the International Linear Collider (ILC). We find that the cross section for t(t-bar)h t in γγ collisions is at the level of a few fb with the c.m. energy √s=1000 GeV, which is consistent with the results of the cross section of t(t-bar)H in the standard model and the cross section of t(t-bar)h in the minimal supersymmetric standard model. It should be clear that hundreds of to thousands of ht per year can be produced at the ILC. This process of γγ→t(t-bar)h t is really interesting in testing the standard model and searching the signs of technicolor. (authors)

Buoyancy Induced Heat Transfer and Fluid Flow Inside a Prismatic Cavity

International Nuclear Information System (INIS)

Aich, Walid; Omri, Ahmed; Ben Nasrallah, Sassi

2009-01-01

This paper deals with a numerical simulation of natural convection flows in a prismatic cavity. This configuration represents solar energy collectors, conventional attic spaces of greenhouses and buildings with pitched roofs. The third dimension of the cavity is considered long enough for the flow to be considered 2D. The base is submitted to a uniform heat flux, the two top inclined walls are symmetrically cooled and the two vertical walls are assumed to be perfect thermal insulators. The aim of the study is to examine the thermal exchange by natural convection and effects of buoyancy forces on flow structure. The study provides useful information on the flow structure sensitivity to the governing parameters, the Rayleigh number (Ra) and the aspect ratio of the cavity. The hydrodynamic and thermal fields, the local Nusselt number, the temperature profile at the bottom and at the center of the cavity are investigated for a large range of Ra. The effect of the aspect ratio is examined for different values of Ra. Based on the authors knowledge, no previous results on natural convection in this geometry exist

Discriminating Z' from anomalous trilinear gauge coupling signatures in e+e- → W+W- at ILC with polarized beams

International Nuclear Information System (INIS)

Andreev, V.V.; Moortgat-Pick, G.; Osland, P.; Pankov, A.A.

2012-05-01

New heavy neutral gauge bosons Z' are predicted by many models of physics beyond the Standard Model. It is quite possible that Z's are heavy enough to lie beyond the discovery reach of the CERN Large Hadron Collider LHC, in which case only indirect signatures of Z' exchanges may emerge at future colliders, through deviations of the measured cross sections from the Standard Model predictions. We discuss in this context the foreseeable sensitivity to Z's of W ± -pair production cross sections at the e + e - International Linear Collider (ILC), especially as regards the potential of distinguishing observable effects of the Z' from analogous ones due to competitor models with anomalous trilinear gauge couplings (AGC) that can lead to the same or similar new physics experimental signatures at the ILC. The sensitivity of the ILC for probing the Z-Z' mixing and its capability to distinguish these two new physics scenarios is substantially enhanced when the polarization of the initial beams and the produced W ± bosons are considered. A model independent analysis of the Z' effects in the process e + e - → W + W - allows to differentiate the full class of vector Z' models from those with anomalous trilinear gauge couplings, with one notable exception: the sequential SM (SSM)-like models can in this process not be distinguished from anomalous gauge couplings. Results of model dependent analysis of a specific Z' are expressed in terms of discovery and identification reaches on the Z-Z' mixing angle and the Z' mass.

Discriminating Z' from anomalous trilinear gauge coupling signatures in e+e-→W+W- at ILC with polarized beams

International Nuclear Information System (INIS)

Andreev, V.V.; Moortgat-Pick, G.; Osland, P.; Pankov, A.A.; Paver, N.

2012-01-01

New heavy neutral gauge bosons Z' are predicted by many models of physics beyond the Standard Model. It is quite possible that Z's are heavy enough to lie beyond the discovery reach of the CERN Large Hadron Collider LHC, in which case only indirect signatures of Z' exchanges may emerge at future colliders, through deviations of the measured cross sections from the Standard Model predictions. We discuss in this context the foreseeable sensitivity to Z's of W ± -pair production cross sections at the e + e - International Linear Collider (ILC), especially as regards the potential of distinguishing observable effects of the Z' from analogous ones due to competitor models with anomalous trilinear gauge couplings (AGC) that can lead to the same or similar new physics experimental signatures at the ILC. The sensitivity of the ILC for probing the Z-Z' mixing and its capability to distinguish these two new physics scenarios is substantially enhanced when the polarization of the initial beams and the produced W ± bosons are considered. A model-independent analysis of the Z' effects in the process e + e - →W + W - allows to differentiate the full class of vector Z' models from those with anomalous trilinear gauge couplings, with one notable exception: the sequential SM (SSM)-like models can in this process not be distinguished from anomalous gauge couplings. Results of model-dependent analysis of a specific Z' are expressed in terms of discovery and identification reaches on the Z-Z' mixing angle and the Z' mass. (orig.)

Nonpolar III-nitride vertical-cavity surface-emitting laser with a photoelectrochemically etched air-gap aperture

Energy Technology Data Exchange (ETDEWEB)

Leonard, J. T., E-mail: jtleona01@gmail.com; Yonkee, B. P.; Cohen, D. A.; Megalini, L.; Speck, J. S. [Materials Department, University of California, Santa Barbara, California 93106 (United States); Lee, S. [Department of Electrical and Computer Engineering, University of California, Santa Barbara, California 93106 (United States); DenBaars, S. P.; Nakamura, S. [Materials Department, University of California, Santa Barbara, California 93106 (United States); Department of Electrical and Computer Engineering, University of California, Santa Barbara, California 93106 (United States)

2016-01-18

We demonstrate a III-nitride nonpolar vertical-cavity surface-emitting laser (VCSEL) with a photoelectrochemically (PEC) etched aperture. The PEC lateral undercut etch is used to selectively remove the multi-quantum well (MQW) region outside the aperture area, defined by an opaque metal mask. This PEC aperture (PECA) creates an air-gap in the passive area of the device, allowing one to achieve efficient electrical confinement within the aperture, while simultaneously achieving a large index contrast between core of the device (the MQW within the aperture) and the lateral cladding of the device (the air-gap formed by the PEC etch), leading to strong lateral confinement. Scanning electron microscopy and focused ion-beam analysis is used to investigate the precision of the PEC etch technique in defining the aperture. The fabricated single mode PECA VCSEL shows a threshold current density of ∼22 kA/cm{sup 2} (25 mA), with a peak output power of ∼180 μW, at an emission wavelength of 417 nm. The near-field emission profile shows a clearly defined single linearly polarized (LP) mode profile (LP{sub 12,1}), which is in contrast to the filamentary lasing that is often observed in III-nitride VCSELs. 2D mode profile simulations, carried out using COMSOL, give insight into the different mode profiles that one would expect to be displayed in such a device. The experimentally observed single mode operation is proposed to be predominantly a result of poor current spreading in the device. This non-uniform current spreading results in a higher injected current at the periphery of the aperture, which favors LP modes with high intensities near the edge of the aperture.

Low-loss tunable 1D ITO-slot photonic crystal nanobeam cavity

Science.gov (United States)

Amin, Rubab; Tahersima, Mohammad H.; Ma, Zhizhen; Suer, Can; Liu, Ke; Dalir, Hamed; Sorger, Volker J.

2018-05-01

Tunable optical material properties enable novel applications in both versatile metamaterials and photonic components including optical sources and modulators. Transparent conductive oxides (TCOs) are able to highly tune their optical properties with applied bias via altering their free carrier concentration and hence plasma dispersion. The TCO material indium tin oxide (ITO) exhibits unity-strong index change and epsilon-near-zero behavior. However, with such tuning the corresponding high optical losses, originating from the fundamental Kramers–Kronig relations, result in low cavity finesse. However, achieving efficient tuning in ITO-cavities without using light–matter interaction enhancement techniques such as polaritonic modes, which are inherently lossy, is a challenge. Here we discuss a novel one-dimensional photonic crystal nanobeam cavity to deliver a cavity system offering a wide range of resonance tuning range, while preserving physical compact footprints. We show that a vertical silicon-slot waveguide incorporating an actively gated-ITO layer delivers ∼3.4 nm of tuning. By deploying distributed feedback, we are able to keep the Q-factor moderately high with tuning. Combining this with the sub-diffraction limited mode volume (0.1 (λ/2n)3) from the photonic (non-plasmonic) slot waveguide, facilitates a high Purcell factor exceeding 1000. This strong light–matter-interaction shows that reducing the mode volume of a cavity outweighs reducing the losses in diffraction limited modal cavities such as those from bulk Si3N4. These tunable cavities enable future modulators and optical sources such as tunable lasers.

Lattice design for an ILC damping ring with 3 km circumference

International Nuclear Information System (INIS)

Wolski, Andrzej

2004-01-01

We describe a simple lattice that meets the specifications for the damping times and horizontal and longitudinal emittances for the International Linear Collider (ILC) damping rings. The circumference of a little over 3 km leads to a bunch spacing of around 3 ns, which will require advances in kicker technology for injection and extraction. We present the lattice design, and initial results of studies of the acceptance and collective effects. With the high bunch charge and close spacing, the ion and electron cloud effects are expected to be severe; however, the simple structure of the lattice allows for easy variation of the circumference and bunch spacing, which may make it useful for future investigations

Large-Grain Superconducting Gun Cavity Testing Program Phase One Closing Report

Energy Technology Data Exchange (ETDEWEB)

Hammons, L. [Brookhaven National Lab. (BNL), Upton, NY (United States); Bellavia, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Belomestnykh, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ben-Zvi, I. [Brookhaven National Lab. (BNL), Upton, NY (United States); Cullen, C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Dai, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Degen, C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Hahn, H. [Brookhaven National Lab. (BNL), Upton, NY (United States); Masi, L. [Brookhaven National Lab. (BNL), Upton, NY (United States); McIntyre, G. [Brookhaven National Lab. (BNL), Upton, NY (United States); Schultheiss, C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Seda, T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Kellerman, R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Tallerico, T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Todd, R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Tuozzolo, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Xu, W. [Brookhaven National Lab. (BNL), Upton, NY (United States); Than, Y. [Brookhaven National Lab. (BNL), Upton, NY (United States)

2013-10-31

This report details the experimental configuration and RF testing results for the first phase of a large-grained niobium electron gun cavity testing program being conducted in the Small Vertical Testing Facility in the Collider-Accelerator Department. This testing is meant to explore multi-pacting in the cavity and shed light on the behavior of a counterpart cavity of identical geometry installed in the Energy Recovery LINAC being constructed in the Collider-Accelerator Department at Brookhaven National Laboratory. This test found that the Q of the large-grained cavity at 4 K reached ~6.5 × 10⁸ and at 2 K reached a value of ~6 × 10⁹. Both of these values are about a factor of 10 lower than would be expected for this type of cavity given the calculated surface resistance and the estimated geometry factor for this half-cell cavity. In addition, the cavity reached a peak voltage of 0.6 MV before there was sig-nificant decline in the Q value and a substantial increase in field emission. This relatively low volt-age, coupled with the low Q and considerable field emission suggest contamination of the cavity interior, possibly during experimental assembly. The results may also suggest that additional chemical etching of the interior surface of the cavity may be beneficial. Throughout the course of testing, various challenges arose including slow helium transfer to the cryostat and cable difficulties. These difficulties and others were eventually resolved, and the re-port discusses the operating experience of the experiment thus far and the plans for future work aimed at exploring the nature of multipacting with a copper cathode inserted into the cavity.

Configuration Studies and Recommendations for the ILC Damping Rings

International Nuclear Information System (INIS)

Wolski, Andrzej; Gao, Jie; Guiducci, Susanna

2006-01-01

We describe the results of studies comparing different options for the baseline configuration of the ILC damping rings. The principal configuration decisions apply to the circumference, beam energy, lattice type, and technology options for key components, including the injection/extraction kickers and the damping wigglers. To arrive at our recommended configuration, we performed detailed studies of a range of lattices representing a variety of different configuration options; these lattices are described in Chapter 2. The results of the various studies are reported in chapters covering issues of beam dynamics, technical subsystems, costs, and commissioning, reliability and upgrade ability. Our detailed recommendations for the baseline configuration are given in Chapter 7, where we also outline further research and development that is needed before a machine using our recommended configuration can be built and operated successfully. In the same chapter, we suggest possible alternatives to the baseline configuration

Tests on model of a prestressed concrete nuclear pressure vessel with multiple cavities

International Nuclear Information System (INIS)

Favre, R.; Koprna, M.; Jaccoud, J.P.

1977-01-01

The prestressed concrete pressure vessel (prototype) is a cylinder having a diameter of 48 m and a height of 39 m. It has 25 vertical cavities (reactor, heat exchangers, heat recuperators) and 3 horizontal cavities (gas turbines of 500 kw). The cavities are closed by plugs, and their tightness is ensured by a steel lining. A model, on a scale of 1/20, made of microconcrete, was loaded in several cycles, by a uniform inner pressure in the cavities, increasing to the point of failure. The three successive stages were examined: stage of globally elastic behavior, cracking stage, ultimate stage. The behavior of the model is globally elastic up to an inner pressure of 120 to 130 kp/cm 2 , corresponding to about twice the maximum pressure of service, equal to 65 kp/cm 2 . The prestressed tendons at this stage show practically no stress increase. The first detectable cracks appear on the lateral side half-way up the model, as soon as the pressure exceeded 120 kp/cm 2 . From 150-165 kp/cm 2 , the cracking stage can be considered as achieved and the main crack pattern entirely formed. A horizontal crack continues in the middle of the barrel, as well as vertical cracks at each outer cavity. Beyond a pressure of 150-165 kp/cm 2 the ultimate stage begins. The strains of the stresses in the tendons grow more rapidly. The steel lining is highly solicited. Above about 210 kp/cm 2 the model behaves like a structure composed of a group of concrete blocks bound by the tendons and the lining. The failure (240 kp/cm 2 ) occurred through a mechanism of ejection and bending of the concrete ring at the periphery of the barrel of the vessel, which was solicited mainly in tension

IV-VI mid-IR tunable lasers and detectors with external resonant cavities

Science.gov (United States)

Zogg, H.; Rahim, M.; Khiar, A.; Fill, M.; Felder, F.; Quack, N.; Blunier, S.; Dual, J.

2009-08-01

Wavelength tunable emitters and detectors in the mid-IR wavelength region allow applications including thermal imaging and spectroscopy. Such devices may be realized using a resonant cavity. By mechanically changing the cavity length with MEMS mirror techniques, the wavelengths may be tuned over a considerable range. Vertical external cavity surface emitting lasers (VECSEL) may be applied for gas spectroscopy. Resonant cavity enhanced detectors (RCED) are sensitive at the cavity resonance only. They may be applied for low resolution spectroscopy, and, when arrays of such detectors are realized, as multicolor IR-FPA or IR-AFPA (IR-adaptive focal plane arrays). We review mid-infrared RCEDs and VECSELs using narrow gap IV-VI (lead chalcogenide) materials like PbTe and PbSe as the active medium. IV-VIs are fault tolerant and allow easy wavelength tuning. The VECSELs operate up to above room temperature and emit in the 4 - 5 μm range with a PbSe active layer. RCEDs with PbTe absorbing layers above 200 K operating temperature have higher sensitivities than the theoretical limit for a similar broad-band detector coupled with a passive tunable band-filter.

Integration of electro-absorption modulator in a vertical-cavity surface-emitting laser

Science.gov (United States)

Marigo-Lombart, L.; Calvez, S.; Arnoult, A.; Rumeau, A.; Viallon, C.; Thienpont, H.; Panajotov, K.; Almuneau, G.

2018-02-01

VCSELs became dominant laser sources in many short optical link applications such as datacenter, active cables, etc. Actual standards and commercialized VCSEL are providing 25 Gb/s data rates, but new solutions are expected to settle the next device generation enabling 100 Gb/s. Directly modulated VCSEL have been extensively studied and improved to reach bandwidths in the range of 26-32 GHz [Chalmers, TU Berlin], however at the price of increased applied current and thus reduced device lifetime. Furthermore, the relaxation oscillation limit still subsists with this solution. Thus, splitting the emission and the modulation functions as done with DFB lasers is a very promising alternative [TI-Tech, TU Berlin]. Here, we study the vertical integration of an ElectroAbsorption Modulator (EAM) within a VCSEL, where the output light of the VCSEL is modulated through the EAM section. In our original design, we finely optimized the EAM design to maximize the modulation depth by implementing perturbative Quantum Confined Stark Effect (QCSE) calculations, while designing the vertical integration of the EAM without penalty on the VCSEL static performances. We will present the different fabricated vertical structures, as well as the experimental electrical and optical static measurements for those configurations demonstrating a very good agreement with the reflectivity and absorption simulations obtained for both the VCSEL and the EAM-VCSEL structures. Finally, to reach very high frequency modulation we studied the BCB electrical properties up to 110 GHz and investigated coplanar and microstrip lines access to decrease both the parasitic capacitance and the influence of the substrate.

Advance in Vertical Buffered Electropolishing on Niobium for Particle Accelerators

International Nuclear Information System (INIS)

Wu, A.T.; Jin, S.; Mammosser, J.D.; Reece, C.E.; Rimmer, R.A.; Lin, L.; Lu, X.Y.; Zhao, K.

2011-01-01

Niobium (Nb) is the most popular material that has been employed for making superconducting radio frequency (SRF) cavities to be used in various particle accelerators over the last couple of decades. One of the most important steps in fabricating Nb SRF cavities is the final chemical removal of 150 μm of Nb from the inner surfaces of the SRF cavities. This is usually done by either buffered chemical polishing (BCP) or electropolishing (EP). Recently a new Nb surface treatment technique called buffered electropolishing (BEP) has been developed at Jefferson Lab. It has been demonstrated that BEP can produce the smoothest surface finish on Nb ever reported in the literature while realizing a Nb removal rate as high as 10 μm/min that is more than 25 and 5 times quicker than those of EP and BCP(112) respectively. In this contribution, recent advance in optimizing and understanding BEP treatment technique is reviewed. Latest results from RF measurements on BEP treated Nb single cell cavities by our unique vertical polishing system will be reported.

Non-homogeneous model for a side heated square cavity filled with a nanofluid

International Nuclear Information System (INIS)

Celli, Michele

2013-01-01

Highlights: • A side heated two dimensional square cavity filled with a nanofluid is studied. • A non-homogeneous model is taken into account. • The properties of the nanofluid are functions of the fraction of nanoparticles. • Low-Rayleigh numbers yield a non-homogeneous distribution of the nanoparticles. -- Abstract: A side heated two dimensional square cavity filled with a nanofluid is here studied. The side heating condition is obtained by imposing two different uniform temperatures at the vertical boundary walls. The horizontal walls are assumed to be adiabatic and all boundaries are assumed to be impermeable to the base fluid and to the nanoparticles. In order to study the behavior of the nanofluid, a non-homogeneous model is taken into account. The thermophysical properties of the nanofluid are assumed to be functions of the average volume fraction of nanoparticles dispersed inside the cavity. The definitions of the nondimensional governing parameters (Rayleigh number, Prandtl number and Lewis number) are exactly the same as for the clear fluids. The distribution of the nanoparticles shows a particular sensitivity to the low Rayleigh numbers. The average Nusselt number at the vertical walls is sensitive to the average volume fraction of the nanoparticles dispersed inside the cavity and it is also sensitive to the definition of the thermophysical properties of the nanofluid. Highly viscous base fluids lead to a critical behavior of the model when the simulation is performed in pure conduction regime. The solution of the problem is obtained numerically by means of a Galerkin finite element method

Lattice Boltzmann simulation for temperature-sensitive magnetic fluids in a porous square cavity

International Nuclear Information System (INIS)

Jin Licong; Zhang Xinrong; Niu Xiaodong

2012-01-01

A lattice Boltzmann method is developed to simulate temperature-sensitive magnetic fluids in a porous cavity. In the simulation, the magnetic force, efficient gravity, viscous loss term and geometric loss term in porous medium are imported to the momentum equation. To test the reliability of the method, a validation with water in porous cavity is carried out. Good agreements with the previous results verify that the present lattice Boltzmann method is promising for simulation of magnetic fluids in porous medium. In this study, we investigate the change of magnetization with external magnetic field, and we present numerical results for the streamlines, isotherms, and magnetization at vertical or horizontal mid-profiles for different values of Ram. In addition, Nusselt numbers changing with magnetic Rayleigh numbers are also investigated. - Highlights: → Developed a lattice Boltzmann method for magnetic nano-fluids in porous cavity. → Clarified flow and heat transfer for different values of (magnetic) Rayleigh numbers. → Heat transfer enhancement for magnetic fluid in porous cavity.

Measuring the Dispersion in Laser Cavity Mirrors using White-Light Interferometry

Science.gov (United States)

2008-03-01

mirrors. Two AlGaInP (aluminum gallium indium phosphide ) diode lasers are aligned such that one is polarized vertically while one is polarized...linear crystals, where the index of refraction depends on beam intensity. Short pulses with high peak intensities are well 14 suited to induce the...MEASURING THE DISPERSION OF LASER CAVITY MIRRORS USING WHITE-LIGHT INTERFEROMETRY THESIS Allison S

Signals of leptophilic dark matter at the ILC

Energy Technology Data Exchange (ETDEWEB)

Dutta, Sukanta [University of Delhi, SGTB Khalsa College, Delhi (India); Rawat, Bharti; Sachdeva, Divya [University of Delhi, Department of Physics and Astrophysics, Delhi (India)

2017-09-15

Adopting a model independent approach, we constrain the various effective interactions of leptophilic DM particles with the visible world from the WMAP and Planck data. The thermally averaged indirect DM annihilation cross section and the DM-electron direct-detection cross section for such a DM candidate are observed to be consistent with the respective experimental data. We study the production of cosmologically allowed leptophilic DM in association with Z (Z → f anti f), f ≡ q, e{sup -}, μ{sup -} at the ILC. We perform the χ{sup 2} analysis and compute the 99% C.L. acceptance contours in the m{sub χ} and Λ plane from the two-dimensional differential distributions of various kinematic observables obtained after employing parton showering and hadronisation to the simulated data. We observe that the dominant hadronic channel provides the best kinematic reach of 2.62 TeV (m{sub χ} = 25 GeV), which further improves to ∝ 3 TeV for polarised beams at √(s) = 1 TeV and an integrated luminosity of 1 ab{sup -1}. (orig.)

An analytic study on laminar film condensation along the interior surface of a cave-shaped cavity of a flat plate heat pipe

International Nuclear Information System (INIS)

Lee, Jin Sung; Kim, Tae Gyu; Park, Tae Sang; Kim, Choong Sik; Park, Chan Hoon

2002-01-01

An analytic approach has been employed to study condensate film thickness distribution inside cave-shaped cavity of a flat plate heat pipe. The results indicate that the condensate film thickness largely depends on mass flow rate and local velocity of condensate. The increasing rate of condensate film for circular region reveals about 50% higher value than that of vertical region. The physical properties of working fluid affect significantly the condensate film thickness, such as the condensate film thickness for the case of FC-40 are 5 times larger than that of water. In comparison with condensation on a vertical wall, the average heat transfer coefficient in the cave-shaped cavity presented 10∼15% lower values due to the fact that the average film thickness formed inside the cave-shaped cavity was larger than that of the vertical wall with an equivalent flow length. A correlation formula which is based on the condensate film analysis for the cave-shaped cavity to predict average heat transfer coefficient is presented. Also, the critical minimum fill charge ratio of working fluid based on condensate film analysis has been predicted, and the minimum fill charge ratios for FC-40 and water are about Ψ crit =3∼7%, Ψ crit =0.5∼1.3%, respectively, in the range of heat flux q = 5∼90kW/m 2

Passive amplification of a fiber laser in a Fabry-Perot cavity: application to gamma-ray production by Compton backscattering

International Nuclear Information System (INIS)

Labaye, F.

2012-01-01

One of the critical points of the International Linear Collider (ILC) is the polarized positrons source. Without going through further explanation on the physical process of polarized positrons production, we point out that they are produced when circularly polarized gamma rays interact with mater. Thus, the critical point is the circularly polarized gamma-ray source. A technical solution for this source is the Compton backscattering and in the end, this thesis takes place in the framework for the design of a high average power laser systems enslaved to Fabry-Perot cavities for polarized gamma-ray production by Compton backscattering. In the first part, we present this thesis context, the Compton backscattering principle and the choice for an optical architecture based on a fiber laser and a Fabry-Perot cavity. We finish by enumerating several possible applications for Compton backscattering which shows that the work presented here might benefits from technology transfer through others research fields. In the second part, we present the different fiber laser architecture studied as well as the results obtained. In the third part, we remind the operating principle of a Fabry-Perot cavity and present the one used for our experiment as well as its specificities. In the fourth part, we address the Compton backscattering experiment which enables us to present the joint utilization of a fiber laser and a Fabry-Perot cavity in a particles accelerator to generate gamma rays for the first time to our knowledge. This experiment took place in the Accelerator Test Facility (ATF). The experimental apparatus as well as the results obtained are thus presented. In the end, we summarize the results presented in this manuscript and propose different evolution possibilities for the system in a general conclusion. (author)

Complex-enhanced chaotic signals with time-delay signature suppression based on vertical-cavity surface-emitting lasers subject to chaotic optical injection

Science.gov (United States)

Chen, Jianjun; Duan, Yingni; Zhong, Zhuqiang

2018-03-01

A chaotic system is constructed on the basis of vertical-cavity surface-emitting lasers (VCSELs), where a slave VCSEL subject to chaotic optical injection (COI) from a master VCSEL with the external feedback. The complex degree (CD) and time-delay signature (TDS) of chaotic signals generated by this chaotic system are investigated numerically via permutation entropy (PE) and self-correlation function (SF) methods, respectively. The results show that, compared with master VCSEL subject to optical feedback, complex-enhanced chaotic signals with TDS suppression can be achieved for S-VCSEL subject to COI. Meanwhile, the influences of several controllable parameters on the evolution maps of CD of chaotic signals are carefully considered. It is shown that the CD of chaotic signals for S-VCSEL is always higher than that for M-VCSEL due to the CIO effect. The TDS of chaotic signals can be significantly suppressed by choosing the reasonable parameters in this system. Furthermore, TDS suppression and high CD chaos can be obtained simultaneously in the specific parameter ranges. The results confirm that this chaotic system may effectively improve the security of a chaos-based communication scheme.

Study of field-limiting defects in superconducting RF cavities for electron-accelerators

International Nuclear Information System (INIS)

Aderhold, Sebastian

2015-02-01

Superconducting radio-frequency resonators made from niobium are an integral part of many accelerator projects. Their main advantage are the low ohmic losses resulting in the possibility for a long pulse structure and high duty cycles up to continous wave (cw) operation. The European X-Ray Free-Electron Laser (XFEL) and the International Linear Collider (ILC) are based on this technology. In some cases the resonators reach accelerating electric fields close to the theoretical limit of bulk niobium. Yet most resonators are limited at lower fields and mass production for large scale accelerator projects suffers from the spread in the achievable gradient per resonator. The main limitations are field emission and the breakdown of superconductivity (quench). While field emission is mostly attributed to the overall surface cleanliness of the resonator, quench is usually associated with local defects. Optical inspection of the inner surface of the resonators with unprecedented resolution, accuracy and a special illumination has been established at DESY and used to study such local surface defects. More than 30 resonators have been inspected. Distinctive features from these inspections have been catalogued and assessed for their potential risk for the performance of the resonator. Several confirmed quenching defects could be extracted for further analysis and could be traced back to likely origins in the production process. A new, automated set-up for optical inspection of large series of resonators, named OBACHT, has been developed and successfully commissioned. Its design includes the minimal need for operator interference, reproducibility, robustness and versatility, in order to fit the requirements for application both in a laboratory and in a production environment. To facilitate the comparison of the results obtained during the global R and D effort on resonators for the ILC, the ILC global yield database has been established. The yield and selection rules for the

Cryogenic rf test of the first SRF cavity etched in an rf Ar/Cl2 plasma

Science.gov (United States)

Upadhyay, J.; Palczewski, A.; Popović, S.; Valente-Feliciano, A.-M.; Im, Do; Phillips, H. L.; Vušković, L.

2017-12-01

An apparatus and a method for etching of the inner surfaces of superconducting radio frequency (SRF) accelerator cavities are described. The apparatus is based on the reactive ion etching performed in an Ar/Cl2 cylindrical capacitive discharge with reversed asymmetry. To test the effect of the plasma etching on the cavity rf performance, a 1497 MHz single cell SRF cavity was used. The single cell cavity was mechanically polished and buffer chemically etched and then rf tested at cryogenic temperatures to provide a baseline characterization. The cavity's inner wall was then exposed to the capacitive discharge in a mixture of Argon and Chlorine. The inner wall acted as the grounded electrode, while kept at elevated temperature. The processing was accomplished by axially moving the dc-biased, corrugated inner electrode and the gas flow inlet in a step-wise manner to establish a sequence of longitudinally segmented discharges. The cavity was then tested in a standard vertical test stand at cryogenic temperatures. The rf tests and surface condition results, including the electron field emission elimination, are presented.

Infinity in Logic and Computation: International Conference, ILC 2007, Cape Town, South Africa, November 3-5, 2007: Revised selected papers

NARCIS (Netherlands)

Archibald, M.; Brattka, V.; Goranko, V.; Löwe, B.

2009-01-01

Edited in collaboration with FoLLI, the Association of Logic, Language and Information, this volume constitutes a selection of papers presented at the Internatonal Conference on Infinity in Logic and Computation, ILC 2007, held in Cape Town, South Africa, in November 2007. The 7 revised papers

Fast Ferroelectric L-Band Tuner for ILC Cavities

Energy Technology Data Exchange (ETDEWEB)

Hirshfield, Jay L

2010-03-15

Design, analysis, and low-power tests are described on a 1.3 GHz ferroelectric tuner that could find application in the International Linear Collider or in Project X at Fermi National Accelerator Laboratory. The tuner configuration utilizes a three-deck sandwich imbedded in a WR-650 waveguide, in which ferroelectric bars are clamped between conducting plates that allow the tuning bias voltage to be applied. Use of a reduced one-third structure allowed tests of critical parameters of the configuration, including phase shift, loss, and switching speed. Issues that were revealed that require improvement include reducing loss tangent in the ferroelectric material, development of a reliable means of brazing ferroelectric elements to copper parts of the tuner, and simplification of the mechanical design of the configuration.

Effect of cooldown and residual magnetic field on the performance of niobium–copper clad superconducting radio-frequency cavity

International Nuclear Information System (INIS)

Dhakal, Pashupati; Ciovati, Gianluigi

2017-01-01

Here, we present the results of rf measurements on a niobium–copper clad superconducting radio-frequency cavity with different cooldown conditions and residual magnetic field in a vertical test Dewar in order to explore the effect of thermal current induced magnetic field and its trapping on the performance of the cavity. The residual resistance, extracted from the Q 0 (T) curves in the temperature range 4.3–1.5 K, showed no dependence on a temperature gradient along the cavity during the cooldown across the critical temperature up to ~50 K m –1 . The rf losses due to the trapping of residual magnetic field during the cavity cooldown were found to be ~4.3 nΩ μT –1 , comparable to the values measured in bulk niobium cavities. An increase of residual resistance following multiple cavity quenches was observed along with evidence of trapping of magnetic flux generated by thermoelectric currents.

Optical Injection Locking of Vertical Cavity Surface-Emitting Lasers: Digital and Analog Applications

Science.gov (United States)

Parekh, Devang

With the rise of mobile (cellphones, tablets, notebooks, etc.) and broadband wireline communications (Fiber to the Home), there are increasing demands being placed on transmitters for moving data from device to device and around the world. Digital and analog fiber-optic communications have been the key technology to meet this challenge, ushering in ubiquitous Internet and cable TV over the past 20 years. At the physical layer, high-volume low-cost manufacturing of semiconductor optoelectronic devices has played an integral role in allowing for deployment of high-speed communication links. In particular, vertical cavity surface emitting lasers (VCSEL) have revolutionized short reach communications and are poised to enter more markets due to their low cost, small size, and performance. However, VCSELs have disadvantages such as limited modulation performance and large frequency chirp which limits fiber transmission speed and distance, key parameters for many fiber-optic communication systems. Optical injection locking is one method to overcome these limitations without re-engineering the VCSEL at the device level. By locking the frequency and phase of the VCSEL by the direct injection of light from another laser oscillator, improved device performance is achieved in a post-fabrication method. In this dissertation, optical injection locking of VCSELs is investigated from an applications perspective. Optical injection locking of VCSELs can be used as a pathway to reduce complexity, cost, and size of both digital and analog fiber-optic communications. On the digital front, reduction of frequency chirp via bit pattern inversion for large-signal modulation is experimentally demonstrated showing up to 10 times reduction in frequency chirp and over 90 times increase in fiber transmission distance. Based on these results, a new reflection-based interferometric model for optical injection locking was established to explain this phenomenon. On the analog side, the resonance

Swept-source optical coherence tomography powered by a 1.3-μm vertical cavity surface emitting laser enables 2.3-mm-deep brain imaging in mice in vivo

Science.gov (United States)

Choi, Woo June; Wang, Ruikang K.

2015-10-01

We report noninvasive, in vivo optical imaging deep within a mouse brain by swept-source optical coherence tomography (SS-OCT), enabled by a 1.3-μm vertical cavity surface emitting laser (VCSEL). VCSEL SS-OCT offers a constant signal sensitivity of 105 dB throughout an entire depth of 4.25 mm in air, ensuring an extended usable imaging depth range of more than 2 mm in turbid biological tissue. Using this approach, we show deep brain imaging in mice with an open-skull cranial window preparation, revealing intact mouse brain anatomy from the superficial cerebral cortex to the deep hippocampus. VCSEL SS-OCT would be applicable to small animal studies for the investigation of deep tissue compartments in living brains where diseases such as dementia and tumor can take their toll.

Engineering, design and prototype tests of a 3.9 GHz transverse-mode superconducting cavity for a radiofrequency-separated kaon beam

International Nuclear Information System (INIS)

Mark S. Champion et al.

2001-01-01

A research and development program is underway to construct superconducting cavities to be used for radiofrequency separation of a Kaon beam at Fermilab. The design calls for installation of twelve 13-cell cavities operating in the 3.9 GHz transverse mode with a deflection gradient of 5 MV/m. They present the mechanical, cryogenic and vacuum design of the cavity, cryomodule, rf power coupler, cold tuner and supporting hardware. The electromagnetic design of the cavity is presented in a companion paper by Wanzenberg and McAshan. The warm tuning system (for field flatness) and the vertical test system is presented along with test results of bench measurements and cold tests on single-cell and five-cell prototypes

Coldbox installation for HL-LHC crab cavity test in the SPS tunnel (BA6)

CERN Document Server

Ordan, Julien Marius

2018-01-01

The Cold-box, produced by Linde Kryotechnik for the SPS crab-cavity test stand for HL-LHC, on its arrival at CERN. It wll be transported into the tunnel in horizontal position and then will have to be tilted in its operational position, on its vertical axis, before connecting it to cryogenics lines.

Development of Infrastructure Facilities for Superconducting RF Cavity Fabrication, Processing and 2 K Characterization at RRCAT

Science.gov (United States)

Joshi, S. C.; Raghavendra, S.; Jain, V. K.; Puntambekar, A.; Khare, P.; Dwivedi, J.; Mundra, G.; Kush, P. K.; Shrivastava, P.; Lad, M.; Gupta, P. D.

2017-02-01

An extensive infrastructure facility is being established at Raja Ramanna Centre for Advanced Technology (RRCAT) for a proposed 1 GeV, high intensity superconducting proton linac for Indian Spallation Neutron Source. The proton linac will comprise of a large number of superconducting Radio Frequency (SCRF) cavities ranging from low beta spoke resonators to medium and high beta multi-cell elliptical cavities at different RF frequencies. Infrastructure facilities for SCRF cavity fabrication, processing and performance characterization at 2 K are setup to take-up manufacturing of large number of cavities required for future projects of Department of Atomic Energy (DAE). RRCAT is also participating in a DAE’s approved mega project on “Physics and Advanced technology for High intensity Proton Accelerators” under Indian Institutions-Fermilab Collaboration (IIFC). In the R&D phase of IIFC program, a number of high beta, fully dressed multi-cell elliptical SCRF cavities will be developed in collaboration with Fermilab. A dedicated facility for SCRF cavity fabrication, tuning and processing is set up. SCRF cavities developed will be characterized at 2K using a vertical test stand facility, which is already commissioned. A Horizontal Test Stand facility has also been designed and under development for testing a dressed multi-cell SCRF cavity at 2K. The paper presents the infrastructure facilities setup at RRCAT for SCRF cavity fabrication, processing and testing at 2K.

Investigation of in-house superconducting radio-frequency 9-cell cavity made of large grain niobium at KEK

Science.gov (United States)

Dohmae, Takeshi; Umemori, Kensei; Yamanaka, Masashi; Watanabe, Yuichi; Inoue, Hitoshi

2017-12-01

The first in-house, 9-cell, superconducting radio-frequency cavity made of large grain Nb was fabricated at KEK. Some characteristic techniques were employed for the fabrication that were not used for fine grain (FG) Nb. Even though a penetrated hole was created during electron beam welding, it was successfully repaired and did not affect the cavity performance. The completed cavity then underwent vertical tests (VTs) via several surface treatment processes. A defect that caused quenches was found after a VT at 25 mm from the equator where the typical local grinding machine developed at KEK could not be utilized. A new local grinding machine using a 3D printer was thus developed for the first time, and it completely removed this defect. Finally, the cavity achieved a maximum Q0 value of 3.8 ×1010 and accelerating gradient of 38 MV/m. The obtained Q0 value is about 1.5 times higher than that for the KEK in-house FG cavity.

Direct visualization of the in-plane leakage of high-order transverse modes in vertical-cavity surface-emitting lasers mediated by oxide-aperture engineering

Science.gov (United States)

Ledentsov, N.; Shchukin, V. A.; Kropp, J.-R.; Burger, S.; Schmidt, F.; Ledentsov, N. N.

2016-03-01

Oxide-confined apertures in vertical cavity surface emitting laser (VCSEL) can be engineered such that they promote leakage of the transverse optical modes from the non- oxidized core region to the selectively oxidized periphery of the device. The reason of the leakage is that the VCSEL modes in the core can be coupled to tilted modes in the periphery if the orthogonality between the core mode and the modes at the periphery is broken by the oxidation-induced optical field redistribution. Three-dimensional modeling of a practical VCSEL design reveals i) significantly stronger leakage losses for high-order transverse modes than that of the fundamental one as high-order modes have a higher field intensity close to the oxide layers and ii) narrow peaks in the far-field profile generated by the leaky component of the optical modes. Experimental 850-nm GaAlAs leaky VCSELs produced in the modeled design demonstrate i) single-mode lasing with the aperture diameters up to 5μm with side mode suppression ratio >20dB at the current density of 10kA/cm2; and ii) narrow peaks tilted at 37 degrees with respect to the vertical axis in excellent agreement with the modeling data and confirming the leaky nature of the modes and the proposed mechanism of mode selection. The results indicate that in- plane coupling of VCSELs, VCSELs and p-i-n photodiodes, VCSEL and delay lines is possible allowing novel photonic integrated circuits. We show that the approach enables design of oxide apertures, air-gap apertures, devices created by impurity-induced intermixing or any combinations of such designs through quantitative evaluation of the leaky emission.

Probing the Standard Model with Higgs signal rates from the Tevatron, the LHC and a future ILC

International Nuclear Information System (INIS)

Bechtle, P.; Staal, O.

2014-03-01

We explore the room for possible deviations from the Standard Model (SM) Higgs boson coupling structure in a systematic study of Higgs coupling scale factor (κ) benchmark scenarios using the latest signal rate measurements from the Tevatron and LHC experiments. We employ a profile likelihood method based on a χ 2 test performed with HiggsSignals, which takes into account detailed information on signal efficiencies and major correlations of theoretical and experimental uncertainties. All considered scenarios allow for additional non-standard Higgs boson decay modes, and various assumptions for constraining the total decay width are discussed. No significant deviations from the SM Higgs boson coupling structure are found in any of the investigated benchmark scenarios. We derive upper limits on an additional (undetectable) Higgs decay mode under the assumption that the Higgs couplings to weak gauge bosons do not exceed the SM prediction. We furthermore discuss the capabilities of future facilities for probing deviations from the SM Higgs couplings, comparing the high luminosity upgrade of the LHC with a future International Linear Collider (ILC), where for the latter various energy and luminosity scenarios are considered. At the ILC model-independent measurements of the coupling structure can be performed, and we provide estimates of the precision that can be achieved.

IOP Latest R&D news and beam test performance of the highly granular SiW-ECAL technological prototype for the ILC

CERN Document Server

Irles, Adrián

2018-02-22

High precision physics at future colliders as the International Linear Collider (ILC) require unprecedented high precision in the determination of the energy of final state particles. The needed precision will be achieved thanks to the Particle Flow algorithms (PF) which require highly granular and hermetic calorimeters systems. The physical proof of concept of the PF was performed in the previous campaign of beam tests of physic prototypes within the CALICE collaboration. One of these prototypes was the physics prototype of the Silicon-Tungsten Electromagnetic Calorimeter (SiW-ECAL) for the International Large Detector at the ILC. In this document we present the latest nes on R&D of the next generation prototype, the technological prototype with fully embedded very front-end (VFE) electronics, of the SiW-ECAL. Special emphasis is given to the presentation and discussion of the first results from the beam test done at DESY in June 2017. The physics program for such beam test consisted in the calibration a...

Vibration diagnostics instrumentation for ILC

OpenAIRE

Bertolini, A.

2007-01-01

The future e-e+ 500 GeV International Linear Collider will rely on unprecedented nanometer scale particle beam size at the interaction point, in order to achieve the design luminosity. Tight tolerances on static and dynamic alignment of the accelerator cavities and optical components are demanded to transport and focus the high energy electron and positron beams with reasonable position jitter and low emittance. A brief review of techniques and devices evaluated and developed so far for the v...

System aspects of the ILC-electronics and power pulsing

CERN Document Server

Götlicher, P

2007-01-01

The requirements for the electronics of an experiment at the international linear collider (ILC) are driven by the bunch structure of the accelerator - short trains (1ms) with bunch to bunch lag of 0.3μs interrupted by long empty intervals (199ms) - and the precision physics. Based on developments of the CALICEcollaboration a system for high granular dense calorimetry is presented. The talk covers the system aspect: — of compact sensors as Si-diodes and multi-pixel Geiger mode photo sensors, — of the electromechanics with components embedded into the PCB’s, — of integrating the functionality needed nearby the sensor into low power ASIC’s, — of a DAQ-chain, in which each channel triggers on its own and the data selection is installed into PC’s and — of calibrating the calorimeter. With the high number of 100 million channels the power consumption and cooling have to be investigated carefully. Calculations demonstrate, that active cooling inside the calorimeters can be avoided. But essential fo...

The International Linear Collider

Directory of Open Access Journals (Sweden)

List Benno

2014-04-01

Full Text Available The International Linear Collider (ILC is a proposed e+e− linear collider with a centre-of-mass energy of 200–500 GeV, based on superconducting RF cavities. The ILC would be an ideal machine for precision studies of a light Higgs boson and the top quark, and would have a discovery potential for new particles that is complementary to that of LHC. The clean experimental conditions would allow the operation of detectors with extremely good performance; two such detectors, ILD and SiD, are currently being designed. Both make use of novel concepts for tracking and calorimetry. The Japanese High Energy Physics community has recently recommended to build the ILC in Japan.

The International Linear Collider

Science.gov (United States)

List, Benno

2014-04-01

The International Linear Collider (ILC) is a proposed e+e- linear collider with a centre-of-mass energy of 200-500 GeV, based on superconducting RF cavities. The ILC would be an ideal machine for precision studies of a light Higgs boson and the top quark, and would have a discovery potential for new particles that is complementary to that of LHC. The clean experimental conditions would allow the operation of detectors with extremely good performance; two such detectors, ILD and SiD, are currently being designed. Both make use of novel concepts for tracking and calorimetry. The Japanese High Energy Physics community has recently recommended to build the ILC in Japan.

Development of digital low level rf system

International Nuclear Information System (INIS)

Michizono, Shinichiro; Anami, Shozo; Katagiri, Hiroaki; Fang, Zhigao; Matsumoto, Toshihiro; Miura, Takako; Yano, Yoshiharu; Yamaguchi, Seiya; Kobayashi, Tetsuya

2008-01-01

One of the biggest advantages of the digital low level rf (LLRF) system is its flexibility. Owing to the recent rapid progress in digital devices (such as ADCs and DACs) and telecommunication devices (mixers and IQ modulators), digital LLRF system becomes popular in these 10 years. The J-PARC linac LLRF system adopted cPCI crates and FPGA based digital feedback system. Since the LLRF control of the normal conducting cavities are more difficult than super conducting cavities due to its lower Q values, fast processing using the FPGA was the essential to the feedback control. After the successful operation of J-PARC linac LLRF system, we developed the STF (ILC test facility in KEK) LLRF system. Since the klystron drives eight cavities in STF phase 1, we modified the FPGA board. Basic configuration and the performances of these systems are summarized. The future R and D projects (ILC and ERL) is also described from the viewpoints of LLRF. (author)

Cryogenic rf test of the first SRF cavity etched in an rf Ar/Cl2 plasma

Directory of Open Access Journals (Sweden)

J. Upadhyay

2017-12-01

Full Text Available An apparatus and a method for etching of the inner surfaces of superconducting radio frequency (SRF accelerator cavities are described. The apparatus is based on the reactive ion etching performed in an Ar/Cl2 cylindrical capacitive discharge with reversed asymmetry. To test the effect of the plasma etching on the cavity rf performance, a 1497 MHz single cell SRF cavity was used. The single cell cavity was mechanically polished and buffer chemically etched and then rf tested at cryogenic temperatures to provide a baseline characterization. The cavity’s inner wall was then exposed to the capacitive discharge in a mixture of Argon and Chlorine. The inner wall acted as the grounded electrode, while kept at elevated temperature. The processing was accomplished by axially moving the dc-biased, corrugated inner electrode and the gas flow inlet in a step-wise manner to establish a sequence of longitudinally segmented discharges. The cavity was then tested in a standard vertical test stand at cryogenic temperatures. The rf tests and surface condition results, including the electron field emission elimination, are presented.

Improvement of cavity performance in the Saclay/Cornell/DESY's SC cavities

International Nuclear Information System (INIS)

Kako, E.; Noguchi, S.; Ono, M.

2000-01-01

Development of 1.3 GHz Nb superconducting cavities for TESLA (TeV Energy Superconducting Linear Collider) has been carried out with international collaboration. Three Saclay single-cell cavities, one Cornell two-cell cavity and one DESY nine-cell cavity were sent to KEK in order to compare the cavity performance. These cavities were tested at KEK after the following surface treatment: 1) high pressure rinsing, HPR, 2) chemical polishing and HPR, 3) electropolishing and HPR. The test results, especially, improvement of the cavity performance due to electropolishing are reported in this paper. (author)

Second-generation PVCC design with a dielectric light injector and polyhedron interior cavity

Science.gov (United States)

Ortabasi, Ugur; Winston, Roland; Ellis, Scott

2006-08-01

The Photovoltaic Cavity Converter (PVCC) under development is a novel approach to convert highly concentrated solar radiation into electricity via a photon entrapment process and subsequent spectral stripping. Equipped with a multi-bandgap, single junction cell system PVCC circumvents most of the present limitations of the four (or more)-junction cell systems with vertical architecture. Our previous studies have shown that the PVCC concept has the potential to reach a collective conversion efficiency of 50% in the near term. Based on our past experiences regarding the cavity geometry and the light injection method we have developed a second generation design for the PVCC that overcomes the limitations of the first generation prototype.

Correction of beam-beam effects in luminosity measurement at ILC

CERN Document Server

Lukic, S

2015-01-01

Three methods for handling beam-beam effects in luminosity measurement at ILC are tested and evaluated in this work. The first method represents an optimization of the LEPtype asymmetric selection cuts that reduce the counting biases. The second method uses the experimentally reconstructed shape of the √ s ′ spectrum to determine the Beamstrahlung component of the bias. The last, recently proposed, collision-frame method relies on the reconstruction of the collision-frame velocity to define the selection function in the collision frame both in experiment and in theory. Thus the luminosity expression is insensitive to the difference between the CM frame of the collision and the lab frame. The collision-frame method is independent of the knowledge of the beam parameters, and it allows an accurate reconstruction of the luminosity spectrum above 80% of the nominal CM energy. However, it gives no precise infromation about luminosity below 80% of the nominal CM energy. The compatibility of diverse selection cut...

Fundamental damper power calculation of the 56 MHz SRF cavity for RHIC

International Nuclear Information System (INIS)

Wu, Q.; Bellavia, S.; Ben-Zvi, I.; Grau, M.; Miglionico, G.; Pai, C.

2011-01-01

At each injection period during RHIC's operation, the beam's frequency sweeps across a wide range, and some of its harmonics will cross the frequency of the 56MHz SRF cavity. To avoid excitation of the cavity at these times, we designed a fundamental damper for the quarter-wave resonator to damp the cavity heavily. The power extracted by the fundamental damper should correspond to the power handling ability of the system at all stages. In this paper, we discuss the power output from the fundamental damper when it is fully extracted, inserted, and any intermediate point. A Fundamental Damper (FD) will greatly reduce the cavity's Q factor to ∼300 during the acceleration phase of the beam. However, when the beam is at store and the FD is removed, the cavity is excited by both the yellow and the blue beams at 2 x 0.3A to attain the required 2MV voltage across its gap. The cavity then is operated to increase the luminosity of the RHIC experiments. Table 1 lists the parameters of the FD. Figure 1 shows the configuration of the FD fully inserted into the 56MHz SRF cavity; this complete insertion is defined as the start location (0cm) of FD simulation, an assumption we make throughout this paper. The power consumed by the cavity while maintaining the beam's energy and its orbit is compensated by the 28MHz accelerating cavities in the storage ring. The power dissipation of the external load is dynamic with respect to the position of the FD during its extraction. As a function of the external Q and the EM field in the cavity, the power should peak with the FD at a certain vertical location. Our calculation of the power extracted is detailed in the following sections. Figure 2 plots the frequency change in the cavity, and the external Q against the changes in position of the FD. The location of the FD is selected carefully such that the frequency will approach the designed working point from the lower side only. The loaded Q of the cavity is 223 when the FD is fully

Computation of coupled surface radiation and natural convection in an inclined form cavity

International Nuclear Information System (INIS)

Amraqui, Samir; Mezrhab, Ahmed; Abid, Cherifa

2011-01-01

The present paper is concerned with computation of the radiation-natural convection interactions in an inclined form cavity. The cavity contains two symmetrically identical isothermal blocks and is vented by two opening located in a vertical median axis at the top and the bottom parts of the cavity. Calculations are made by using a finite volume method and an efficient numerical procedure is introduced for calculating the view factors, with shadow effects included. Effects of Rayleigh number Ra and inclination angle φ are investigated for Pr = 0.71 in presence and in absence of the radiation exchange. Results are reported in terms of isotherms, streamlines, local and average Nusselt numbers and mass flow rate. In light of the obtained results, we can conclude that the heat transfer decreases with increasing φ. In addition, the increase of Ra and the taking into account of the radiation exchange produce a considerable increase in the heat transfer.

Validation of the superconducting 3.9 GHz cavity package for the European X-ray Free Electron Laser

Science.gov (United States)

Maiano, C. G.; Branlard, J.; Hüning, M.; Jensch, K.; Kostin, D.; Matheisen, A.; Möller, W.-D.; Sulimov, A.; Vogel, E.; Bosotti, A.; Chen, J. F.; Moretti, M.; Paparella, R.; Pierini, P.; Sertore, D.

2017-04-01

A full test of the cavity package concept under realistic operating condition was a necessary step before the assembly of the European XFEL (EXFEL) 3.9 GHz superconducting system and its installation in the accelerator. One cavity, equipped with magnetic shielding, power coupler and frequency tuner has been tested in a specially designed single cavity cryostat in one of the test benches of the DESY Accelerator Module Test Facility (AMTF). The cavity was operated at high pulsed power up to an accelerating field of 24 MV /m , above the quench accelerating field of 21 MV /m achieved during the continuous wave (CW) vertical qualification test and with a large margin with respect to the EXFEL maximum operating specification of 15 MV /m for the 3.9 GHz system. All subsystems under test—coupler, tuner, waveguide tuners, low level radio-frequency (LLRF) system—were qualified to their design performances.

An iterative model for the steady state current distribution in oxide-confined vertical-cavity surface-emitting lasers (VCSELs)

Science.gov (United States)

Chuang, Hsueh-Hua

The purpose of this dissertation is to develop an iterative model for the analysis of the current distribution in vertical-cavity surface-emitting lasers (VCSELs) using a circuit network modeling approach. This iterative model divides the VCSEL structure into numerous annular elements and uses a circuit network consisting of resistors and diodes. The measured sheet resistance of the p-distributed Bragg reflector (DBR), the measured sheet resistance of the layers under the oxide layer, and two empirical adjustable parameters are used as inputs to the iterative model to determine the resistance of each resistor. The two empirical values are related to the anisotropy of the resistivity of the p-DBR structure. The spontaneous current, stimulated current, and surface recombination current are accounted for by the diodes. The lateral carrier transport in the quantum well region is analyzed using drift and diffusion currents. The optical gain is calculated as a function of wavelength and carrier density from fundamental principles. The predicted threshold current densities for these VCSELs match the experimentally measured current densities over the wavelength range of 0.83 mum to 0.86 mum with an error of less than 5%. This model includes the effects of the resistance of the p-DBR mirrors, the oxide current-confining layer and spatial hole burning. Our model shows that higher sheet resistance under the oxide layer reduces the threshold current, but also reduces the current range over which single transverse mode operation occurs. The spatial hole burning profile depends on the lateral drift and diffusion of carriers in the quantum wells but is dominated by the voltage drop across the p-DBR region. To my knowledge, for the first time, the drift current and the diffusion current are treated separately. Previous work uses an ambipolar approach, which underestimates the total charge transferred in the quantum well region, especially under the oxide region. However, the total

Evaluation Of Silicon Diodes As IN-SITU Cryogenic Field Emission Detectors For SRF Cavity Development

International Nuclear Information System (INIS)

Palczewski, Ari; Geng, Rongli

2012-01-01

We performed in-situ cryogenic testing of four silicon diodes as possible candidates for field emission (FE) monitors of superconducting radio frequency (SRF) cavities during qualification testing and in accelerator cryo-modules. We evaluated diodes from 2 companies - from Hamamatsu corporation model S1223-01; and from OSI Optoelectronics models OSD35-LR-A, XUV-50C, and FIL-UV20. The measurements were done by placing the diodes in superfluid liquid helium near the top of a field emitting 9-cell cavity during its vertical test. For each diode, we will discuss their viability as a 2K cryogenic detector for FE mapping of SRF cavities and the directionality of S1223-01 in such environments. We will also present calibration curves between the diodes and JLab's standard radiation detector placed above the Dewar's top plate.

Mixed convection of ferrofluids in a lid driven cavity with two rotating cylinders

Directory of Open Access Journals (Sweden)

Fatih Selimefendigil

2015-09-01

Full Text Available Mixed convection of ferrofluid filled lid driven cavity in the presence of two rotating cylinders were numerically investigated by using the finite element method. The cavity is heated from below, cooled from driven wall and rotating cylinder surfaces and side vertical walls of the cavity are assumed to be adiabatic. A magnetic dipole source is placed below the bottom wall of the cavity. The study is performed for various values of Reynolds numbers (100 ≤ Re ≤ 1000, angular rotational speed of the cylinders (−400 ≤ Ω ≤ 400, magnetic dipole strengths (0 ≤ γ ≤ 500, angular velocity ratios of the cylinders (0.25≤Ωi/Ωj≤4 and diameter ratios of the cylinders (0.5≤Di/Dj≤2. It is observed that flow patterns and thermal transport within the cavity are affected by variation in Reynolds number and magnetic dipole strength. The results of this investigation revealed that cylinder angular velocities, ratio of the angular velocities and diameter ratios have profound effect on heat transfer enhancement within the cavity. Averaged heat transfer enhancements of 181.5 % is achieved for clockwise rotation of the cylinder at Ω = −400 compared to motionless cylinder case. Increasing the angular velocity ratio from Ω2/Ω1=0.25 to Ω2/Ω1=4 brings about 91.7 % of heat transfer enhancement.

Vibration diagnostics instrumentation for ILC

Energy Technology Data Exchange (ETDEWEB)

Bertolini, A.

2007-06-15

The future e{sup -}e{sup +} 500 GeV International Linear Collider will rely on unprecedented nanometer scale particle beam size at the interaction point, in order to achieve the design luminosity. Tight tolerances on static and dynamic alignment of the accelerator cavities and optical components are demanded to transport and focus the high energy electron and positron beams with reasonable position jitter and low emittance. A brief review of techniques and devices evaluated and developed so far for the vibration diagnostics of the machine is presented in this paper. (orig.)

Vibration diagnostics instrumentation for ILC

International Nuclear Information System (INIS)

Bertolini, A.

2007-06-01

The future e - e + 500 GeV International Linear Collider will rely on unprecedented nanometer scale particle beam size at the interaction point, in order to achieve the design luminosity. Tight tolerances on static and dynamic alignment of the accelerator cavities and optical components are demanded to transport and focus the high energy electron and positron beams with reasonable position jitter and low emittance. A brief review of techniques and devices evaluated and developed so far for the vibration diagnostics of the machine is presented in this paper. (orig.)

Complete one-loop electroweak corrections to ZZZ production at the ILC

International Nuclear Information System (INIS)

Su Jijuan; Ma Wengan; Zhang Renyou; Wang Shaoming; Guo Lei

2008-01-01

We study the complete O(α ew ) electroweak (EW) corrections to the production of three Z 0 bosons in the framework of the standard model (SM) at the ILC. The leading-order and the EW next-to-leading-order corrected cross sections are presented, and their dependence on the colliding energy √(s) and Higgs-boson mass m H is analyzed. We investigate also the LO and one-loop EW corrected distributions of the transverse momentum of the final Z 0 boson, and the invariant mass of the Z 0 Z 0 pair. Our numerical results show that the EW one-loop correction generally suppresses the tree-level cross section, and the relative correction with m H =120 GeV(150 GeV) varies between -15.8%(-13.9%) and -7.5%(-6.2%) when √(s) goes up from 350 GeV to 1 TeV.

Systematic characterization of a 1550 nm microelectromechanical (MEMS)-tunable vertical-cavity surface-emitting laser (VCSEL) with 7.92 THz tuning range for terahertz photomixing systems

Science.gov (United States)

Haidar, M. T.; Preu, S.; Cesar, J.; Paul, S.; Hajo, A. S.; Neumeyr, C.; Maune, H.; Küppers, F.

2018-01-01

Continuous-wave (CW) terahertz (THz) photomixing requires compact, widely tunable, mode-hop-free driving lasers. We present a single-mode microelectromechanical system (MEMS)-tunable vertical-cavity surface-emitting laser (VCSEL) featuring an electrothermal tuning range of 64 nm (7.92 THz) that exceeds the tuning range of commercially available distributed-feedback laser (DFB) diodes (˜4.8 nm) by a factor of about 13. We first review the underlying theory and perform a systematic characterization of the MEMS-VCSEL, with particular focus on the parameters relevant for THz photomixing. These parameters include mode-hop-free CW tuning with a side-mode-suppression-ratio >50 dB, a linewidth as narrow as 46.1 MHz, and wavelength and polarization stability. We conclude with a demonstration of a CW THz photomixing setup by subjecting the MEMS-VCSEL to optical beating with a DFB diode driving commercial photomixers. The achievable THz bandwidth is limited only by the employed photomixers. Once improved photomixers become available, electrothermally actuated MEMS-VCSELs should allow for a tuning range covering almost the whole THz domain with a single system.

Development of high pressure rinsing set up for 650 MHz, 5- cell superconducting RF cavity cleaning

International Nuclear Information System (INIS)

Suhane, S.K.; Chauhan, S.K.; Bose, A.; Kokil, S.V.; Rajput, D.S.; Oraon, B.; Md Hussain; Sahu, A.; Raghavendra, S.; Joshi, S.C.

2015-01-01

High pressure rinsing (HPR) is an ultra-cleanliness process for the surface preparation of high field superconducting RF cavities. Any dust particle or chemical residue on the interior of cavity causes field emission. Jets of high pressure (80-100 bar) ultra pure water dislodge surface contaminants that normally resist removal with conventional rinsing procedures, leading to substantial reduction in field emission and better cavity performance. For cleaning of 650 MHz, 5-cell SRF cavities, a high pressure rinsing set up has been developed at RRCAT. The HPR tool has a rotating wand coaxial with the vertically mounted SRF cavity that is moving up and down. Fan style spray nozzles are attached to the end of the rotating wand and the water jets emerging from spray nozzles scan the entire internal surface of the cavity. The set-up was installed in a specially built clean area meeting cleanliness class 100 standards. The ultrapure water with resistivity 2 ≥ 18 MΩ-cm required for rinsing is obtained from a dedicated water purification system installed for this purpose. The paper describes the salient design and constructional details of the high pressure rinsing set up. Characterization of water jet parameters based on the momentum transfer between the water jet and a load cell is also presented. (author)

Numerical study of a heated cavity insulated by a horizontal laminar jet

Energy Technology Data Exchange (ETDEWEB)

Besbes, S.; Mhiri, H.; El Golli, S. [Ecole Nationale d' Ingenieurs de Monastir (Tunisia). Lab. de Mecanique des Fluides et Thermique; Le Palec, G.; Bournot, P. [Institut de Mecanique de Marseille (France)

2001-08-01

In this work, we present a numerical study of the thermal insulation of a heated two dimensional cavity limited on its superior part by a horizontal plane air jet. The lower horizontal wall is isothermal, while the two vertical walls are adiabatics. A finite difference method based on the stream function-vorticity formulation is developed to solve the dimensionless Navier-Stokes and energy equations resulting from some assumptions. The results allowed us to point out two flow configurations: if natural convection prevails, the hot jet issuing from the nozzle diffuses upwards, and consequently, the cavity cannot be insulated correctly. However, the use of an aspiration zone can then improve the insulation. When forced convection predominates, the hydrodynamic barrier is conserved, and the enclosure is also thermally well confined. (author)

MHD natural convection in open inclined square cavity with a heated circular cylinder

Science.gov (United States)

Hosain, Sheikh Anwar; Alim, M. A.; Saha, Satrajit Kumar

2017-06-01

MHD natural convection in open cavity becomes very important in many scientific and engineering problems, because of it's application in the design of electronic devices, solar thermal receivers, uncovered flat plate solar collectors having rows of vertical strips, geothermal reservoirs, etc. Several experiments and numerical investigations have been presented for describing the phenomenon of natural convection in open cavity for two decades. MHD natural convection and fluid flow in a two-dimensional open inclined square cavity with a heated circular cylinder was considered. The opposite wall to the opening side of the cavity was first kept to constant heat flux q, at the same time the surrounding fluid interacting with the aperture was maintained to an ambient temperature T∞. The top and bottom wall was kept to low and high temperature respectively. The fluid with different Prandtl numbers. The properties of the fluid are assumed to be constant. As a result a buoyancy force is created inside the cavity due to temperature difference and natural convection is formed inside the cavity. The Computational Fluid Dynamics (CFD) code are used to discretize the solution domain and represent the numerical result to graphical form.. Triangular meshes are used to obtain the solution of the problem. The streamlines and isotherms are produced, heat transfer parameter Nu are obtained. The results are presented in graphical as well as tabular form. The results show that heat flux decreases for increasing inclination of the cavity and the heat flux is a increasing function of Prandtl number Pr and decreasing function of Hartmann number Ha. It is observed that fluid moves counterclockwise around the cylinder in the cavity. Various recirculations are formed around the cylinder. The almost all isotherm lines are concentrated at the right lower corner of the cavity. The object of this work is to develop a Mathematical model regarding the effect of MHD natural convection flow around

Cooling tests of the cryomodules at superconducting RF test facility (STF)

International Nuclear Information System (INIS)

Ohuchi, Norihito; Nakai, Hirotaka; Kojima, Yuuji

2009-01-01

KEK has been constructing the Superconducting RF Test Facility (STF) with aiming at a center of the ILC-R and D in Asia from 2005. In this project, KEK targets manufacturing and operational experiences of the RF cavity and cryomodule toward the ILC, and two cryomodules have been developed. These cryomodules are 6 meter long and have 4 nine-cell cavities in each cryostat. The designs of the cryomodules are based on the TESLA Type-3 (TTF-3) at DESY, however, each cryostat has the different type of cavities, TESLA-like type and Low-Loss type. The tests of the cryomodules were performed in two steps. In the first test, measurements of the cryogenic performances of these cryomodules were the main objective. One nine-cell cavity was assembled in each cryomodule and cool-down of the two cryomodules was performed, individually. In the second test, the four TESLA-like cavities were assembled in the cryomodule as complete integration. Cool-down of the cryomodule to 2 K was successfully completed, and thermal performances of the cryomodule and cooling capacity of the cryogenics system were studied in detail. In this paper, we will report the design of the cryomodules and the thermal performances at these cold tests. (author)

NLO QCD corrections to off-shell t anti t and t anti tH at the ILC

International Nuclear Information System (INIS)

Reuter, Juergen; Chokoufe Nejad, Bijan; Weiss, Christian

2017-01-01

We discuss top-quark physics at the ILC with a focus on the full off-shell processes for t anti t and t anti tH production, including top-quark decays and also leptonic W decays. A special focus is on the matching of the resummed vNRQCD threshold calculation and the fixed-order NLO QCD continuum calculation, where we present an update on the validation of the matching. All of the calculations have been performed in the WHIZARD event generator framework.

Fabrication, Tuning, Treatment and Testing of Two 3.5 Cell Photo-Injektor Cavities for the ELBE Linac

CERN Document Server

Arnold, A; Teichert, J; Xiang, R; Eremeev, G V; Kneisel, P; Stirbet, M; Turlington, L

2011-01-01

As part of a CRADA (Cooperative Research and Development Agreement) between Helmholtz-Zentrum Dresden-Rossendorf (HZDR) and Thomas Jefferson Lab National Accelerator Facility (TJNAF) we have fabricated and tested two 1.3 GHz 3.5 cell photo-injector cavities from polycrystalline RRR niobium and large grain RRR niobium, respectively. The cavity with the better performance will replace the presently used injector cavity in the ELBE linac [1]. The cavities have been fabricated and pre-tuned at TJNAF, while the more sophisticated final field tuning; the adjustment of the external couplings and the field profile measurement of transverse electric modes for RF focusing [2] was done at HZDR. The following standard surface treatment and the vertical test were carried out at TJNAF’s production facilities. A major challenge turned out to be the rinsing of the cathode cell, which has small opening (Ø10 mm) to receive the cathode stalk. Another unexpected problem encountered after etching, since large visible defects a...

Intrabeam Scattering Studies for the ILC Damping Rings Using a NewMATLAB Code

Energy Technology Data Exchange (ETDEWEB)

Reichel, I.; Wolski, A.

2006-06-21

A new code to calculate the effects of intrabeam scattering (IBS) has been developed in MATLAB based on the approximation suggested by K. Bane. It interfaces with the Accelerator Toolbox but can also read in lattice functions from other codes. The code has been benchmarked against results from other codes for the ATF that use this approximation or do the calculation in a different way. The new code has been used to calculate the emittance growth due to intrabeam scattering for the lattices currently proposed for the ILC Damping Rings, as IBS is a concern, especially for the electron ring. A description of the code and its user interface, as well as results for the Damping Rings, will be presented.

Intrabeam Scattering Studies for the ILC Damping Rings Using a New MATLAB Code

International Nuclear Information System (INIS)

Reichel, I.; Wolski, A.

2006-01-01

A new code to calculate the effects of intrabeam scattering (IBS) has been developed in MATLAB based on the approximation suggested by K. Bane. It interfaces with the Accelerator Toolbox but can also read in lattice functions from other codes. The code has been benchmarked against results from other codes for the ATF that use this approximation or do the calculation in a different way. The new code has been used to calculate the emittance growth due to intrabeam scattering for the lattices currently proposed for the ILC Damping Rings, as IBS is a concern, especially for the electron ring. A description of the code and its user interface, as well as results for the Damping Rings, will be presented

Climate Modeling: Ocean Cavities below Ice Shelves

Energy Technology Data Exchange (ETDEWEB)

Petersen, Mark Roger [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Computer, Computational, and Statistical Sciences Division

2016-09-12

The Accelerated Climate Model for Energy (ACME), a new initiative by the U.S. Department of Energy, includes unstructured-mesh ocean, land-ice, and sea-ice components using the Model for Prediction Across Scales (MPAS) framework. The ability to run coupled high-resolution global simulations efficiently on large, high-performance computers is a priority for ACME. Sub-ice shelf ocean cavities are a significant new capability in ACME, and will be used to better understand how changing ocean temperature and currents influence glacial melting and retreat. These simulations take advantage of the horizontal variable-resolution mesh and adaptive vertical coordinate in MPAS-Ocean, in order to place high resolution below ice shelves and near grounding lines.

A Many-Atom Cavity QED System with Homogeneous Atom-Cavity Coupling

OpenAIRE

Lee, Jongmin; Vrijsen, Geert; Teper, Igor; Hosten, Onur; Kasevich, Mark A.

2013-01-01

We demonstrate a many-atom-cavity system with a high-finesse dual-wavelength standing wave cavity in which all participating rubidium atoms are nearly identically coupled to a 780-nm cavity mode. This homogeneous coupling is enforced by a one-dimensional optical lattice formed by the field of a 1560-nm cavity mode.

Segmented trapped vortex cavity

Science.gov (United States)

Grammel, Jr., Leonard Paul (Inventor); Pennekamp, David Lance (Inventor); Winslow, Jr., Ralph Henry (Inventor)

2010-01-01

An annular trapped vortex cavity assembly segment comprising includes a cavity forward wall, a cavity aft wall, and a cavity radially outer wall there between defining a cavity segment therein. A cavity opening extends between the forward and aft walls at a radially inner end of the assembly segment. Radially spaced apart pluralities of air injection first and second holes extend through the forward and aft walls respectively. The segment may include first and second expansion joint features at distal first and second ends respectively of the segment. The segment may include a forward subcomponent including the cavity forward wall attached to an aft subcomponent including the cavity aft wall. The forward and aft subcomponents include forward and aft portions of the cavity radially outer wall respectively. A ring of the segments may be circumferentially disposed about an axis to form an annular segmented vortex cavity assembly.

Comparison of Wenner and dipole–dipole arrays in the study of an underground three-dimensional cavity

International Nuclear Information System (INIS)

Neyamadpour, Ahmad; Wan Abdullah, W A T; Taib, Samsudin; Neyamadpour, Behrang

2010-01-01

The objective of this paper was to compare Wenner and dipole–dipole configurations in delineating an underground cavity at a site near the University of Malaya, Malaysia. A three-dimensional electrical resistivity imaging survey was carried out along seven parallel lines using Wenner and dipole–dipole arrays. A three-dimensional least-squares algorithm, based on the robust inversion method, was used in the inversion of the apparent resistivity data. In the inverted model, both the horizontal and vertical extents of the anomalous zones were displayed. Results indicate the superiority of the Wenner array over the dipole–dipole array for determining the vertical distribution of the subsurface resistivity, although the dipole–dipole array produced a better lateral extent of the subsurface features. The results show that the three-dimensional electrical resistivity imaging survey using both the Wenner and dipole–dipole arrays, in combination with an appropriate three-dimensional inversion method and synthetic model analysis, can be highly useful for engineering and environmental applications, especially for underground three-dimensional cavity detection

Latest R&D news and beam test performance of the highly granular SiW-ECAL technological prototype for the ILC

Science.gov (United States)

Irles, A.

2018-02-01

High precision physics at future colliders as the International Linear Collider (ILC) require unprecedented high precision in the determination of the energy of final state particles. The needed precision will be achieved thanks to the Particle Flow algorithms (PF) which require highly granular and hermetic calorimeters systems. The physical proof of concept of the PF was performed in the previous campaign of beam tests of physic prototypes within the CALICE collaboration. One of these prototypes was the physics prototype of the Silicon-Tungsten Electromagnetic Calorimeter (SiW-ECAL) for the ILC. In this document we present the latest news on R&D of the next generation prototype, the technological prototype with fully embedded very front-end (VFE) electronics, of the SiW-ECAL. Special emphasis is given to the presentation and discussion of the first results from the beam test done at DESY in June 2017. The physics program for such beam test consisted in the calibration and commissioning of the current set of available SiW ECAL modules; the test of performance of individual slabs under 1T magnetic fields; and the study of electromagnetic showers events.

Implosion of the small cavity and large cavity cannonball targets

International Nuclear Information System (INIS)

Nishihara, Katsunobu; Yamanaka, Chiyoe.

1984-01-01

Recent results of cannonball target implosion research are briefly reviewed with theoretical predictions for GEKKO XII experiments. The cannonball targets are classified into two types according to the cavity size ; small cavity and large cavity. The compression mechanisms of the two types are discussed. (author)

Efficient Characterization of Protein Cavities within Molecular Simulation Trajectories: trj_cavity.

Science.gov (United States)

Paramo, Teresa; East, Alexandra; Garzón, Diana; Ulmschneider, Martin B; Bond, Peter J

2014-05-13

Protein cavities and tunnels are critical in determining phenomena such as ligand binding, molecular transport, and enzyme catalysis. Molecular dynamics (MD) simulations enable the exploration of the flexibility and conformational plasticity of protein cavities, extending the information available from static experimental structures relevant to, for example, drug design. Here, we present a new tool (trj_cavity) implemented within the GROMACS ( www.gromacs.org ) framework for the rapid identification and characterization of cavities detected within MD trajectories. trj_cavity is optimized for usability and computational efficiency and is applicable to the time-dependent analysis of any cavity topology, and optional specialized descriptors can be used to characterize, for example, protein channels. Its novel grid-based algorithm performs an efficient neighbor search whose calculation time is linear with system size, and a comparison of performance with other widely used cavity analysis programs reveals an orders-of-magnitude improvement in the computational cost. To demonstrate its potential for revealing novel mechanistic insights, trj_cavity has been used to analyze long-time scale simulation trajectories for three diverse protein cavity systems. This has helped to reveal, respectively, the lipid binding mechanism in the deep hydrophobic cavity of a soluble mite-allergen protein, Der p 2; a means for shuttling carbohydrates between the surface-exposed substrate-binding and catalytic pockets of a multidomain, membrane-proximal pullulanase, PulA; and the structural basis for selectivity in the transmembrane pore of a voltage-gated sodium channel (NavMs), embedded within a lipid bilayer environment. trj_cavity is available for download under an open-source license ( http://sourceforge.net/projects/trjcavity ). A simplified, GROMACS-independent version may also be compiled.

Mixed convection in a lid-driven square cavity with partial slip

International Nuclear Information System (INIS)

Ismael, Muneer A.; Pop, Ioan; Chamkha, Ali J.

2014-01-01

Steady laminar mixed convection inside a lid-driven square cavity filled with water is studied numerically. The lid is due to the movement of the isothermal top and bottom walls which are maintained at T c and T h , respectively, with T h is higher than T c . A partial slip condition was imposed in these two moving walls. The vertical walls of the cavity are kept adiabatic. The appliance of the numerical analysis was USR finite difference method with upwind scheme treatments of the convective terms included in the momentum and energy equations. The studied relevant parameters were: the partial slip parameter S (0-∞); Richardson number Ri (0.01-100) and the direction of the moving walls (λ t = 1, λ b = ±1). The results have showed that there are critical values for the partial slip parameter at which the convection is declined. (authors)

Validation of the superconducting 3.9 GHz cavity package for the European X-ray Free Electron Laser

Directory of Open Access Journals (Sweden)

C. G. Maiano

2017-04-01

Full Text Available A full test of the cavity package concept under realistic operating condition was a necessary step before the assembly of the European XFEL (EXFEL 3.9 GHz superconducting system and its installation in the accelerator. One cavity, equipped with magnetic shielding, power coupler and frequency tuner has been tested in a specially designed single cavity cryostat in one of the test benches of the DESY Accelerator Module Test Facility (AMTF. The cavity was operated at high pulsed power up to an accelerating field of 24  MV/m, above the quench accelerating field of 21  MV/m achieved during the continuous wave (CW vertical qualification test and with a large margin with respect to the EXFEL maximum operating specification of 15  MV/m for the 3.9 GHz system. All subsystems under test—coupler, tuner, waveguide tuners, low level radio-frequency (LLRF system—were qualified to their design performances.

Export of Ice-Cavity Water from Pine Island Ice Shelf, West Antarctica

Science.gov (United States)

Thurnherr, Andreas; Jacobs, Stanley; Dutrieux, Pierre

2013-04-01

Stability of the West Antarctic Ice Sheet is sensitive to changes in melting at the bottom of floating ice shelves that form the seaward extensions of Antarctic glaciers flowing into the ocean. Not least because observations in the cavities beneath ice shelves are difficult, heat fluxes and melt rates have been inferred from oceanographic measurements obtained near the ice edge (calving fronts). Here, we report on a set of hydrographic and velocity data collected in early 2009 near the calving front of the Amundsen Sea's fast-moving and (until recently) accelerating Pine Island Glacier and its associated ice shelf. CTD profiles collected along the southern half of the meridionally-trending ice front show clear evidence for export of ice-cavity water. That water was carried in the upper ocean along the ice front by a southward current that is possibly related to a striking clockwise gyre that dominated the (summertime) upper-ocean circulation in Pine Island Bay. Signatures of ice-cavity water appear unrelated to current direction along most of the ice front, suggesting that cross-frontal exchange is dominated by temporal variability. However, repeated hydrographic and velocity measurements in a small "ice cove" at the southern end of the calving front show a persistent strong (mean velocity peaking near 0.5 ms-1) outflow of ice-cavity water in the upper 500 m. While surface features (boils) suggested upwelling from deep below the ice shelf, vertical velocity measurements reveal 1) that the mean upwelling within the confines of the cove was too weak to feed the observed outflow, and 2) that large high-frequency internal waves dominated the vertical motion of water inside the cove. These observations indicate that water exchange between the Pine Island Ice Shelf cavity and the Amundsen sea is strongly asymmetric with weak broad inflow at depth and concentrated surface-intensified outflow of melt-laden deep water at the southern edge of the calving front. The lack of

Noise Performance of a 72 m Suspended FABRY-PÉROT Cavity

Science.gov (United States)

Dumas, Jean-Charles; Ju, Li; Barriga, Pablo; Zhao, Chunnong; Woolley, Andrew A.; Blair, David G.

We report on a seismic isolator with a relatively compact 3 m stack, combining new passive isolation techniques. It consists of three cascaded passive 3D isolator stages suspended from an Ultra Low Frequency (ULF) horizontal Robert linkage stage which itself is suspended from a ULF 3D pre-isolator. The 3D isolators use self-damping pendulums and Euler springs for the horizontal and vertical stages respectively, while the 3D pre-isolator is the combination of an inverse pendulum which provides low frequency horizontal pre-isolation, and a LaCoste linkage for low frequency vertical pre-isolation. Two isolators suspending mirror test masses have been built to form a 72 m optical cavity in order to test their performance. We report results which demonstrate residual motion at nanometer level at frequencies above 1 Hz.

Red-cockaded woodpecker nest-cavity selection: relationships with cavity age and resin production

Science.gov (United States)

Richard N. Conner; Daniel Saenz; D. Craig Rudolph; William G. Ross; David L. Kulhavy

1998-01-01

The authors evaluated selection of nest sites by male red-cockaded woodpeckers (Picoides borealis) in Texas relative to the age of the cavity when only cavities excavated by the woodpeckers were available and when both naturally excavated cavities and artificial cavities were available. They also evaluated nest-cavity selection relative to the ability of naturally...

Longitudinal Single-Bunch Instability in the ILC Damping Rings: Estimate of Current Threshold

International Nuclear Information System (INIS)

Venturini, Marco; Venturini, Marco

2008-01-01

Characterization of single-bunch instabilities in the International Linear Collider (ILC) damping rings (DRs) has been indicated as a high-priority activity toward completion of an engineering design. In this paper we report on a first estimate of the current thresholds for the instability using numerical and analytical models of the wake potentials associated with the various machine components. The numerical models were derived (upon appropriate scaling) from designs of the corresponding components installed in existing machines. The current thresholds for instabilities were determined by numerical solution of the Vlasov equation for the longitudinal dynamics. For the DR baseline lattice as of Feb. 2007 we find the critical current for instability to be safely above the design specifications leaving room for further optimization of the choice of the momentum compaction

Dental cavities

Science.gov (United States)

... this page: //medlineplus.gov/ency/article/001055.htm Dental cavities To use the sharing features on this page, please enable JavaScript. Dental cavities are holes (or structural damage) in the ...

Ultrafast pulse amplification in mode-locked vertical external-cavity surface-emitting lasers

Energy Technology Data Exchange (ETDEWEB)

Böttge, C. N., E-mail: boettge@optics.arizona.edu; Hader, J.; Kilen, I.; Moloney, J. V. [College of Optical Sciences, The University of Arizona, 1630 E. University Blvd., Tucson, Arizona 85721 (United States); Koch, S. W. [College of Optical Sciences, The University of Arizona, 1630 E. University Blvd., Tucson, Arizona 85721 (United States); Department of Physics and Material Sciences Center, Philipps-Universität Marburg, Renthof 5, 35032 Marburg (Germany)

2014-12-29

A fully microscopic many-body Maxwell–semiconductor Bloch model is used to investigate the influence of the non-equilibrium carrier dynamics on the short-pulse amplification in mode-locked semiconductor microlaser systems. The numerical solution of the coupled equations allows for a self-consistent investigation of the light–matter coupling dynamics, the carrier kinetics in the saturable absorber and the multiple-quantum-well gain medium, as well as the modification of the light field through the pulse-induced optical polarization. The influence of the pulse-induced non-equilibrium modifications of the carrier distributions in the gain medium and the saturable absorber on the single-pulse amplification in the laser cavity is identified. It is shown that for the same structure, quantum wells, and gain bandwidth the non-equilibrium carrier dynamics lead to two preferred operation regimes: one with pulses in the (sub-)100 fs-regime and one with multi-picosecond pulses. The recovery time of the saturable absorber determines in which regime the device operates.

Superconducting TESLA cavities

Directory of Open Access Journals (Sweden)

B. Aune

2000-09-01

Full Text Available The conceptional design of the proposed linear electron-positron collider TESLA is based on 9-cell 1.3 GHz superconducting niobium cavities with an accelerating gradient of E_{acc}≥25 MV/m at a quality factor Q_{0}≥5×10^{9}. The design goal for the cavities of the TESLA Test Facility (TTF linac was set to the more moderate value of E_{acc}≥15 MV/m. In a first series of 27 industrially produced TTF cavities the average gradient at Q_{0}=5×10^{9} was measured to be 20.1±6.2 MV/m, excluding a few cavities suffering from serious fabrication or material defects. In the second production of 24 TTF cavities, additional quality control measures were introduced, in particular, an eddy-current scan to eliminate niobium sheets with foreign material inclusions and stringent prescriptions for carrying out the electron-beam welds. The average gradient of these cavities at Q_{0}=5×10^{9} amounts to 25.0±3.2 MV/m with the exception of one cavity suffering from a weld defect. Hence only a moderate improvement in production and preparation techniques will be needed to meet the ambitious TESLA goal with an adequate safety margin. In this paper we present a detailed description of the design, fabrication, and preparation of the TESLA Test Facility cavities and their associated components and report on cavity performance in test cryostats and with electron beam in the TTF linac. The ongoing research and development towards higher gradients is briefly addressed.

Reynolds number and end-wall effects on a lid-driven cavity flow

International Nuclear Information System (INIS)

Prasad, A.K.; Koseff, J.R.

1989-01-01

A series of experiments has been conducted in a lid-driven cavity of square cross section (depth = width = 150 mm) for Reynolds numbers (Re, based on lid speed and cavity width) between 3200 and 10 000, and spanwise aspect ratios (SAR) between 0.25:1 and 1:1. Flow visualization using polystyrene beads and two-dimensional laser-Doppler anemometer (LDA) measurements have shed new light on the momentum transfer processes within the cavity. This paper focuses on the variation, with Re and SAR, of the mean and the rms velocities profiles, as well as the /similar to/(U'V') profile, along the horizontal and vertical centerlines in the symmetry plane. In addition, the contribution of the large-scale ''organized structures,'' and the high-frequency ''turbulent'' velocity fluctuations to the total rms is examined. At low Re, the organized structures account for most of the energy contained in the flow irrespective of SAR. As the Re increases, however, so does the energy content of the higher frequency fluctuations. This trend is not independent of SAR; a reduction in the SAR causes the ''organized structures'' to again become more evident

Precision natural SUSY at CEPC, FCC-ee, and ILC

International Nuclear Information System (INIS)

Fan, JiJi; Reece, Matthew; Wang, Lian-Tao

2015-01-01

Testing the idea of naturalness is and will continue to be one of the most important goals of high energy physics experiments. It will play a central role in the physics program of future colliders. In this paper, we present projections of the reach of natural SUSY at future lepton colliders: CEPC, FCC-ee and ILC. We focus on the observables which give the strongest reach, the electroweak precision observables (for left-handed stops), and Higgs to gluon and photon decay rates (for both left- and right-handed stops). There is a “blind spot” when the stop mixing parameter X t is approximately equal to the average stop mass. We argue that in natural scenarios, bounds on the heavy Higgs bosons from tree-level mixing effects that modify the hbb̄ coupling together with bounds from b→sγ play a complementary role in probing the blind spot region. For specific natural SUSY scenarios such as folded SUSY in which the top partners do not carry Standard Model color charges, electroweak precision observables could be the most sensitive probe. In all the scenarios discussed in this paper, the combined set of precision measurements will probe down to a few percent in fine-tuning.

Cryogenic testing of the 2.1 GHz five-cell superconducting RF cavity with a photonic band gap coupler cell

Science.gov (United States)

Arsenyev, Sergey A.; Temkin, Richard J.; Haynes, W. Brian; Shchegolkov, Dmitry Yu.; Simakov, Evgenya I.; Tajima, Tsuyoshi; Boulware, Chase H.; Grimm, Terrence L.; Rogacki, Adam R.

2016-05-01

We present results from cryogenic tests of the multi-cell superconducting radio frequency (SRF) cavity with a photonic band gap (PBG) coupler cell. Achieving high average beam currents is particularly desirable for future light sources and particle colliders based on SRF energy-recovery-linacs (ERLs). Beam current in ERLs is limited by the beam break-up instability, caused by parasitic higher order modes (HOMs) interacting with the beam in accelerating cavities. A PBG cell incorporated in an accelerating cavity can reduce the negative effect of HOMs by providing a frequency selective damping mechanism, thus allowing significantly higher beam currents. The multi-cell cavity was designed and fabricated of niobium. Two cryogenic (vertical) tests were conducted. The high unloaded Q-factor was demonstrated at a temperature of 4.2 K at accelerating gradients up to 3 MV/m. The measured value of the unloaded Q-factor was 1.55 × 108, in agreement with prediction.

Discriminating Z' from anomalous trilinear gauge coupling signatures in e{sup +}e{sup -} {yields} W{sup +}W{sup -} at ILC with polarized beams

Energy Technology Data Exchange (ETDEWEB)

Andreev, V.V. [F. Scorina Gomel State Univ. (Belarus); Moortgat-Pick, G. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Osland, P. [Bergen Univ. (Norway). Dept. of Physics and Technology; European Organization for Nuclear Research (CERN), Geneva (Switzerland); Pankov, A.A. [Technical Univ. of Gomel (Belarus). The Abdus Salam ICTP Affiliated Centre; Paver, N. [Trieste Univ. (Italy); INFN-Trieste Section (Italy)

2012-05-15

New heavy neutral gauge bosons Z' are predicted by many models of physics beyond the Standard Model. It is quite possible that Z's are heavy enough to lie beyond the discovery reach of the CERN Large Hadron Collider LHC, in which case only indirect signatures of Z' exchanges may emerge at future colliders, through deviations of the measured cross sections from the Standard Model predictions. We discuss in this context the foreseeable sensitivity to Z's of W{sup {+-}}-pair production cross sections at the e{sup +}e{sup -} International Linear Collider (ILC), especially as regards the potential of distinguishing observable effects of the Z' from analogous ones due to competitor models with anomalous trilinear gauge couplings (AGC) that can lead to the same or similar new physics experimental signatures at the ILC. The sensitivity of the ILC for probing the Z-Z' mixing and its capability to distinguish these two new physics scenarios is substantially enhanced when the polarization of the initial beams and the produced W{sup {+-}} bosons are considered. A model independent analysis of the Z' effects in the process e{sup +}e{sup -} {yields} W{sup +}W{sup -} allows to differentiate the full class of vector Z' models from those with anomalous trilinear gauge couplings, with one notable exception: the sequential SM (SSM)-like models can in this process not be distinguished from anomalous gauge couplings. Results of model dependent analysis of a specific Z' are expressed in terms of discovery and identification reaches on the Z-Z' mixing angle and the Z' mass.

Discriminating Z' from anomalous trilinear gauge coupling signatures in e{sup +}e{sup -}{yields}W{sup +}W{sup -} at ILC with polarized beams

Energy Technology Data Exchange (ETDEWEB)

Andreev, V.V. [The F. Scorina Gomel State University, Gomel (Belarus); Moortgat-Pick, G. [DESY FLC, Hamburg (Germany); Osland, P. [University of Bergen, Department of Physics and Technology, Bergen (Norway); CERN, Geneve 23 (Switzerland); Pankov, A.A. [Technical University of Gomel, The Abdus Salam ICTP Affiliated Centre, Gomel (Belarus); Paver, N. [University of Trieste and INFN-Trieste Section, Trieste (Italy)

2012-09-15

New heavy neutral gauge bosons Z' are predicted by many models of physics beyond the Standard Model. It is quite possible that Z's are heavy enough to lie beyond the discovery reach of the CERN Large Hadron Collider LHC, in which case only indirect signatures of Z' exchanges may emerge at future colliders, through deviations of the measured cross sections from the Standard Model predictions. We discuss in this context the foreseeable sensitivity to Z's of W{sup {+-}}-pair production cross sections at the e {sup +} e {sup -} International Linear Collider (ILC), especially as regards the potential of distinguishing observable effects of the Z' from analogous ones due to competitor models with anomalous trilinear gauge couplings (AGC) that can lead to the same or similar new physics experimental signatures at the ILC. The sensitivity of the ILC for probing the Z-Z' mixing and its capability to distinguish these two new physics scenarios is substantially enhanced when the polarization of the initial beams and the produced W {sup {+-}} bosons are considered. A model-independent analysis of the Z' effects in the process e {sup +}e{sup -}{yields}W{sup +}W{sup -} allows to differentiate the full class of vector Z' models from those with anomalous trilinear gauge couplings, with one notable exception: the sequential SM (SSM)-like models can in this process not be distinguished from anomalous gauge couplings. Results of model-dependent analysis of a specific Z' are expressed in terms of discovery and identification reaches on the Z-Z' mixing angle and the Z' mass. (orig.)

Cavity quantum electrodynamics

International Nuclear Information System (INIS)

Walther, Herbert; Varcoe, Benjamin T H; Englert, Berthold-Georg; Becker, Thomas

2006-01-01

This paper reviews the work on cavity quantum electrodynamics of free atoms. In recent years, cavity experiments have also been conducted on a variety of solid-state systems resulting in many interesting applications, of which microlasers, photon bandgap structures and quantum dot structures in cavities are outstanding examples. Although these phenomena and systems are very interesting, discussion is limited here to free atoms and mostly single atoms because these systems exhibit clean quantum phenomena and are not disturbed by a variety of other effects. At the centre of our review is the work on the one-atom maser, but we also give a survey of the entire field, using free atoms in order to show the large variety of problems dealt with. The cavity interaction can be separated into two main regimes: the weak coupling in cavity or cavity-like structures with low quality factors Q and the strong coupling when high-Q cavities are involved. The weak coupling leads to modification of spontaneous transitions and level shifts, whereas the strong coupling enables one to observe a periodic exchange of photons between atoms and the radiation field. In this case, atoms and photons are entangled, this being the basis for a variety of phenomena observed, some of them leading to interesting applications in quantum information processing. The cavity experiments with free atoms reached a new domain with the advent of experiments in the visible spectral region. A review on recent achievements in this area is also given

Operation of a novel hot-electron vertical-cavity surface-emitting laser

Science.gov (United States)

Balkan, Naci; O'Brien-Davies, Angela; Thoms, A. B.; Potter, Richard J.; Poolton, Nigel; Adams, Michael J.; Masum, J.; Bek, Alpan; Serpenguzel, Ali; Aydinli, Atilla; Roberts, John S.

1998-07-01

The hot Electron Light Emission and Lasing in Semiconductor Heterostructures devices (HELLISH-1) is novel surface emitter consisting of a GaAs quantum well, within the depletion region, on the n side of Ga1-xAlxAs p- n junction. It utilizes hot electron transport parallel to the layers and injection of hot electron hole pairs into the quantum well through a combination of mechanisms including tunnelling, thermionic emission and diffusion of `lucky' carriers. Super Radiant HELLISH-1 is an advanced structure incorporating a lower distributed Bragg reflector (DBR). Combined with the finite reflectivity of the upper semiconductor-air interface reflectivity it defines a quasi- resonant cavity enabling emission output from the top surface with a higher spectral purity. The output power has increased by two orders of magnitude and reduced the full width at half maximum (FWHM) to 20 nm. An upper DBR added to the structure defines HELLISH-VCSEL which is currently the first operational hot electron surface emitting laser and lases at room temperature with a 1.5 nm FWHM. In this work we demonstrate and compare the operation of UB-HELLISH-1 and HELLISH-VCSEL using experimental and theoretical reflectivity spectra over an extensive temperature range.

Distinguishing Little-Higgs product and simple group models at the LHC and ILC

International Nuclear Information System (INIS)

Kilian, W.; Rainwater, D.

2006-09-01

We propose a means to discriminate between the two basic variants of Little Higgs models, the Product Group and Simple Group models, at the next generation of colliders. It relies on a special coupling of light pseudoscalar particles present in Little Higgs models, the pseudo-axions, to the Z and the Higgs boson, which is present only in Simple Group models. We discuss the collider phenomenology of the pseudo-axion in the presence of such a coupling at the LHC, where resonant production and decay of either the Higgs or the pseudo-axion induced by that coupling can be observed for much of parameter space. The full allowed range of parameters, including regions where the observability is limited at the LHC, is covered by a future ILC, where double scalar production would be a golden channel to look for. (orig.)

Distinguishing Little-Higgs product and simple group models at the LHC and ILC

Energy Technology Data Exchange (ETDEWEB)

Kilian, W. [Siegen Univ. (Gesamthochschule) (Germany). Fachbereich 7 - Physik]|[Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Rainwater, D. [Rochester Univ., NY (United States). Dept. of Physics and Astronomy; Reuter, J. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

2006-09-15

We propose a means to discriminate between the two basic variants of Little Higgs models, the Product Group and Simple Group models, at the next generation of colliders. It relies on a special coupling of light pseudoscalar particles present in Little Higgs models, the pseudo-axions, to the Z and the Higgs boson, which is present only in Simple Group models. We discuss the collider phenomenology of the pseudo-axion in the presence of such a coupling at the LHC, where resonant production and decay of either the Higgs or the pseudo-axion induced by that coupling can be observed for much of parameter space. The full allowed range of parameters, including regions where the observability is limited at the LHC, is covered by a future ILC, where double scalar production would be a golden channel to look for. (orig.)

Thermal conditions within tree cavities in ponderosa pine (Pinus ponderosa) forests: potential implications for cavity users

Science.gov (United States)

Vierling, Kerri T.; Lorenz, Teresa J.; Cunningham, Patrick; Potterf, Kelsi

2017-11-01

Tree cavities provide critical roosting and breeding sites for multiple species, and thermal environments in these cavities are important to understand. Our objectives were to (1) describe thermal characteristics in cavities between June 3 and August 9, 2014, and (2) investigate the environmental factors that influence cavity temperatures. We placed iButtons in 84 different cavities in ponderosa pine (Pinus ponderosa) forests in central Washington, and took hourly measurements for at least 8 days in each cavity. Temperatures above 40 °C are generally lethal to developing avian embryos, and 18% of the cavities had internal temperatures of ≥ 40 °C for at least 1 h of each day. We modeled daily maximum cavity temperature, the amplitude of daily cavity temperatures, and the difference between the mean internal cavity and mean ambient temperatures as a function of several environmental variables. These variables included canopy cover, tree diameter at cavity height, cavity volume, entrance area, the hardness of the cavity body, the hardness of the cavity sill (which is the wood below the cavity entrance which forms the barrier between the cavity and the external environment), and sill width. Ambient temperature had the largest effect size for maximum cavity temperature and amplitude. Larger trees with harder sills may provide more thermally stable cavity environments, and decayed sills were positively associated with maximum cavity temperatures. Summer temperatures are projected to increase in this region, and additional research is needed to determine how the thermal environments of cavities will influence species occupancy, breeding, and survival.

Measurement of Higgs decay to WW$^{*}$ in Higgsstrahlung at $\\sqrt{s}=500$ GeV ILC and in WW-fusion at $\\sqrt{s}=3$ TeV CLIC

CERN Document Server

AUTHOR|(SzGeCERN)718111

2017-01-01

This talk presents results of the two independent analyses evaluating the measurement accuracy of the branching ratio for the Standard model Higgs boson decay to a W-pair, at the Compact Linear Collider (CLIC) and at the International Linear Collider (ILC). The considered Higgs production channels are the WW-fusion for the highest energy stage of CLIC, $\\sqrt{s}=3$ TeV, and the Higgsstrahlung process for the nominal ILC energy, $\\sqrt{s}=500$ GeV. Both studies are performed using the full simulation of the detector. The realistic experimental conditions have been simulated including beam energy spectrum, initial state radiation and the background from $\\gamma \\gamma \\rightarrow hadrons$ processes, which are overlaid on simulated events. The multivariate analysis technique is used for the final event selection and the expected relative statistical uncertainty, $\\Delta ( \\sigma \\cdot BR)/(\\sigma \\cdot BR)$, of the measured Higgs production cross sections is estimated.

Improved reactor cavity

International Nuclear Information System (INIS)

Katz, L.R.; Demarchais, W.E.

1984-01-01

A reactor pressure vessel disposed in a cavity has coolant inlet or outlet pipes extending through passages in the cavity walls and welded to pressure nozzles. The cavity wall has means for directing fluid away from a break at a weld away from the pressure vessel, and means for inhibiting flow of fluid toward the vessel. (author)

Final Report for 'Modeling Electron Cloud Diagnostics for High-Intensity Proton Accelerators'

International Nuclear Information System (INIS)

Veitzer, Seth A.

2009-01-01

Electron clouds in accelerators such as the ILC degrade beam quality and limit operating efficiency. The need to mitigate electron clouds has a direct impact on the design and operation of these accelerators, translating into increased cost and reduced performance. Diagnostic techniques for measuring electron clouds in accelerating cavities are needed to provide an assessment of electron cloud evolution and mitigation. Accurate numerical modeling of these diagnostics is needed to validate the experimental techniques. In this Phase I, we developed detailed numerical models of microwave propagation through electron clouds in accelerating cavities with geometries relevant to existing and future high-intensity proton accelerators such as Project X and the ILC. Our numerical techniques and simulation results from the Phase I showed that there was a high probability of success in measuring both the evolution of electron clouds and the effects of non-uniform electron density distributions in Phase II.

Design of an interaction region with head-on collisions for the ILC