This proposal is to the Department of Energy for 501.6K dollars (349.6K operations and 152K equipment) for continued participation in the UA1 experiment on proton-antiproton collisions. The UA1 experiment is the study of high-energy proton-antiproton collisions in the Super-Proton-synchrotron (SPS) Collider at CERN. A major upgrade of the UA1 detector is in progress for operation with the upgraded antiproton source (ACOL). The US groups have played an increasingly prominent role in UA1 during the past few years. This paper discusses the data analysis that has been done by the group of the position detector and it`s hardware.

The UA1 central detector was crucial to understanding the complex topology of proton-antiproton events. It played a most important role in identifying a handful of Ws and Zs among billions of collisions. The detector was a 6-chamber cylindrical assembly 5.8 m long and 2.3 m in diameter, the largest imaging drift chamber of its day. It recorded the tracks of charged particles curving in a 0.7 Tesla magnetic field, measuring their momentum, the sign of their electric charge and their rate of energy loss (dE/dx). Atoms in the argon-ethane gas mixture filling the chambers were ionised by the passage of charged particles. The electrons which were released drifted along an electric field shaped by field wires and were collected on sense wires. The geometrical arrangement of the 17000 field wires and 6125 sense wires allowed a spectacular 3-D interactive display of reconstructed physics events to be produced.

Detector for the UA2 experiment, for the study of proton-antiproton collisions in the SPS between 1981 and 1993. It was used, along with UA1 (another experiment on the SPS), to discover the W and Z bosons in 1983, which won Carlo Rubbia and Simon van der Meer the Nobel Prize in 1984.

In March 1982 the central derector of UA1 was contaminated by dirt in the compressed air used for cooling during the bakeout of the beam pipe. The lengthy cleaning imposed a change of the collider schedule (Annual Report 1982 p. 114).

In the first phase of operation of the UA1 experiment, 700 $ nb ^- ^{1} $ of integrated luminosity were accumulated at the Sp$\\bar{p}$S collider up to the end of 1985. Published results include first observation and measurements of W and Z bosons, significant limits on the top quark, heavy lepton and supersymmetric particle masses, observation of $ B \\bar{B} $ mixing, studies of b~quark production and tests of QCD using jet, intermediate boson and photon production.\\\\ \\\\ For the second phase of operation the following items were upgraded for the high luminosity 1988 and 1989 collider runs: the muon detection system was improved by extra iron shielding, partly magnetised and instrumented with Iarocci tubes; the data acquisition system was redesigned using VME to prov speed and second level trigger capacity followed by a farm of 318E emulators for on-line event reconstruction and selection; the central detector was equipped with a laser calibration system. A total of 5 $ pb ^- ^{1} $ of mainly muon-triggered da...

The T2K experiment will study neutrino oscillation properties by directing a high intensity neutrino beam produced at J-PARC in Tokai, Japan, towards the large super-Kamiokande detector located 295km away, in Kamioka, Japan. The experiment includes a sophisticated near detector complex, 280m downstream of the neutrino production target. A key element of the near detectors is the ND280 tracker consisting of two active scintillator-bar target systems surrounded by three large time projection chambers (TPCs) for charged particle tracking. The tracker will provide high statistics samples for studying charged current neutrino interaction rates and kinematics prior to oscillation, so as to better understand backgrounds in the far detector. The tracker is surrounded by the UA1/Nomad dipole magnet...

Calorimetry using scintillator plates or tiles alternated with sheets of (usually heavy) passive absorber has been proven over multiple generations of collider detectors. Recent detectors including UA1, CDF, and ZEUS have shown good results from such calorimeters. The advantages offered by scintillator calorimetry for the SSC environment, in particular, are speed (<10 nsec), excellent energy resolution, low noise, and ease of achieving compensation and hence linearity. On the negative side of the ledger can be placed the historical sensitivity of plastic scintillators to radiation damage, the possibility of nonuniform response because of light attenuation, and the presence of cracks for light collection via wavelength shifting plastic (traditionally in sheet form). This approach to calorimetry is being investigated for SSC use by a collaboration of Ames Laboratory/Iowa State University, Argonne National Laboratory, Bicron Corporation, Florida State University, Louisiana State University, University of Mississippi, Oak Ridge National Laboratory, Virginia Polytechnic Institute and State University, Westinghouse Electric Corporation, and University of Wisconsin.

The T2K experiment is designed to study neutrino oscillation properties by directing a high intensity neutrino beam produced at J-PARC in Tokai, Japan, towards the large Super-Kamiokande detector located 295 km away, in Kamioka, Japan. The experiment includes a sophisticated near detector complex, 280 m downstream of the neutrino production target in order to measure the properties of the neutrino beam and to better understand neutrino interactions at the energy scale below a few GeV. A key element of the near detectors is the ND280 tracker, consisting of two active scintillator-bar target systems surrounded by three large time projection chambers (TPCs) for charged particle tracking. The data collected with the tracker are used to study charged current neutrino interaction rates and kinematics prior to oscillation, in order to reduce uncertainties in the oscillation measurements by the far detector. The tracker is surrounded by the former UA1/NOMAD dipole magnet and the TPCs measure the charges, momenta, and particle types of charged particles passing through them. Novel features of the TPC design include its rectangular box layout constructed from composite panels, the use of bulk micromegas detectors for gas amplification, electronics readout based on a new ASIC, and a photoelectron calibration system. This paper describes the design and construction of the TPCs, the micromegas modules, the readout electronics, the gas handling system, and shows the performance of the TPCs as deduced from measurements with particle beams, cosmic rays, and the calibration system.

The 9th Topical Workshop on Proton-Antiproton Collider Physics in Tsukuba Japan demonstrated clearly the enormous breadth of physics accessible in hadron cowders. Although no significant chinks were reported in the armor of the Standard Model, new results presented in this meeting have expanded our knowledge of the electroweak and strong interactions and have extended the searches for non-standard phenomena significantly. Much of the new data reported came from the CDF and D0 experiments at the Fermilab cowder. Superb operation of the Tevatron during the 1992-1993 Run and significant advances on the detector fronts -- in particular, the emergence of the new D0 detector as a productive physics instrument in its first outing and the addition of the CDF silicon vertex detector -- enabled much of this advance. It is noteworthy however that physics from the CERN collider experiments UA1 and UA4 continued to make a large impact at this meeting. In addition, very interesting summary talks were given on new results from HERA, cosmic ray experiments, on super-hadron collider physics, and on e{sup +}e{sup {minus}} experiments at LEP and TRISTAN. These summaries are reported in elsewhere in this volume.

The {Lambda}{sub b} baryon has been observed recently by UA1 through its decay {Lambda}{sub b} {yields} J/{psi}{Lambda}{degrees}. Although CDF finds twice as many J/{psi} and observes {Lambda}{degrees} decays, no evidence for an {Lambda}{sub b} signal is seen. The UA1 data supports a lower than expected production P{sub T} for the {Lambda}{sub b}, and therefore, a lower pion P{sub T}, below the observation threshold of CDF. This result suggests that UA1 and CDF are probably not inconsistent, but also that the production models are not quite right.

The silicon central tracker of the GEM detector has been simulated using the high energy physics simulations code GEANT. This paper will describe the level of detail of the geometry of the tracker that is in the code, including the silicon detectors themselves as well as all non-sensitive volumes such as support structures; the digitization, or detector response to particles, of the silicon detectors; the coordinate reconstruction from the digitizations, and some of the results of the simulations regarding the detector performance.

The potential of CMS as a heavy ion detector is described with special emphasis on the study of the central rapidity region. The detector provides excellent measurements of leptons, photons, gauge bosons, jets and quarkonia. Thus CMS serves as an unbiased detector for Pb+Pb events at root S //n//n = 5.5 TeV.

This report discusses the following topics on the Soleoidal Detector Collaboration: Summary and overview of the detector; physics and detector requirements; central tracking system; superconducting magnet; calorimetry; muon system; electronics; online computing; offline computing; safety; experimental facilities; installation; test and calibration beam plan; and cost and schedule summary.

Development and prototyping efforts directed towards construction of a new vertex detector for the STAR experiment at the RHIC accelerator at BNL are presented. This new detector will extend the physics range of STAR by allowing for precision measurements of yields and spectra of particles containing heavy quarks. The innermost central part of the new detector is a high resolution pixel-type detector (PIXEL). PIXEL requirements are discussed as well as a conceptual mechanical design, a sensor development path, and a detector readout architecture. Selected progress with sensor prototypes dedicated to the PIXEL detector is summarized and the approach chosen for the readout system architecture validated in tests of hardware prototypes is discussed.

We investigate $U_A(1)$ breaking above $T_c$ in terms of the Dirac spectrum on configurations with (2+1)-flavors, using the HISQ action. The strange quark mass is at its physical value. We use several light quark masses corresponding to the Goldstone pion masses in the range of about 115 -- 230 MeV on lattices of size 32$^3 \\times$8 and 48$^3 \\times$8. We calculate the 100 lowest-lying Dirac eigenvalues at temperatures below and above $T_c$. We investigate the volume dependence of the Dirac eigenvalue density to determine whether there is a gap around zero, which can appear if $U_A(1)$ symmetry is restored in the chiral symmetric phase. We also investigate the quark mass dependence of the Dirac eigenvalue density at zero and check whether there is a linear behavior that would signal the $U_A(1)$ breaking above $T_c$.

Here, the central toroidal magnet. Near the beam pipe, Cristina Vannini works at the vertex detector made of drift chambers, located inside the magnet around the interaction region. (centre, down) Jacques Bouad. Gunter Feilhauer works on top of the magnet.

Both ATLAS members and the team engaged in transport and reception, of the lower part of the central barrel of the tile hadronic calorimeter, will not forget installation of the first active piece of the detector!

We propose a method for reading and encoding the information from the Central Tracker of the Heavy Ion Dedicated Detector at LHC. This method will also be suitable for other detectors such as CMS, ATLAS and the like. It enables one to reduce the (number of cables coming out of the detector) x (information reading, encoding and selection time) factor by 12 times compared to what one has with the FASTPLEX system.

The Transition Radiation Detector (TRD) of ALICE will serve to identify and track electrons in the central region. In this contribution, after a brief introduction of TRD, we review the detector performance concerning electron/pion identification as well as J/? and Upsilon detection.

The MUNU experiment has been built to measure the neutrino magnetic moment at a reactor. Its central part, at the same time target and detector, is a 1 m{sup 3} TPC filled with 3 bar of CF4. This TPC is surrounded by active and passive vetos. Data taking has started and the measured performance of this detector will be shown.

Micromegas detectors on bulk are used in a new design of the central tracker for the future Cebaf Large Acceptance Spectrometer 12 (CLAS12) in Hall B at Jefferson Lab. Expected performances and mechanical designs are shown for this cylindrical detector. First tests in moderate magnetic field up to 1.5 T, using a laser source, are in good agreement with simulations.

This image shows a Z0 particle decaying to an electron and positron in the upgraded UA2 detector. The tracks of the positron and electron are reconstructed in the central detector and their energy measured in the UA2 calorimeter.

Vacuum chamber for intersection I-4 of the ISR being assembled inside a wooden mock-up of the gap of the split-field magnet. The central round-cylinder section is provisional and is to be replaced by an elliptic-cylinder section to give more space vertically for installation of detectors. Supports for the central section are of carbon fibre composite.

This report describes the activities of the Heavy Ion Physics Group at the University of California, Riverside from October 1, 1992 to August 31, 1993. During this period, our AGS E802/E859/E866 experiments focused on strange particle production, and the fluctuation phenomenon associated with correlation studies in nucleus nucleus central collisions. We have designed and are implementing a new detector to replace the Target Multiplicity Array (TMA) for the E866 runs. As part of the PHENIX collaboration, we contributed to the Conceptual Design Report (CDR), and worked on a RHIC silicon microstrip detector R&D project, the central core of the multiplicity-vertex detector (MVD). In the coming year, we planned to complete the New Multiplicity Array (NMA) detector for the gold projectile E866 experiment, and analyzed the data associated with this new system. We are continuing our efforts in the preparation of the PHENIX detector system.

OPAL was one of the four experiments installed at the LEP particle accelerator from 1989 - 2000. OPAL's central tracking system consists of (in order of increasing radius) a silicon microvertex detector, a vertex detector, a jet chamber, and z-chambers. All the tracking detectors work by observing the ionization of atoms by charged particles passing by: when the atoms are ionized, electrons are knocked out of their atomic orbitals, and are then able to move freely in the detector. These ionization electrons are detected in the different parts of the tracking system. (This piece includes the vertex, jet and Z chambers) In the picture above, the central detector is the piece being removed to the right.

The Transition Radiation Detector (TRD) for the ALICE experiment at the Large Hadron Collider (LHC) identifies electrons in p+p and in the challenging high multiplicity environment of heavy-ion collisions and provides fast online tracking for the ALICE Level1 trigger. The TRD is designed to have excellent position resolution and pion rejection capability. Presently, six of the 18 TRD supermodules are installed in the ALICE central barrel. In 2008, four supermodules were installed and commissioning of the detector using cosmic ray tracks was successfully performed. We briefly describe the design of the detector and report on the performance and current understanding of the detector based on these data.

The ALPHA experiment has succeeded in trapping antihydrogen, a major milestone on the road to spectroscopic comparisons of antihydrogen with hydrogen. An annihilation vertex detector, which determines the time and position of antiproton annihilations, has been central to this achievement. This detector, an array of double-sided silicon microstrip detector modules arranged in three concentric cylindrical tiers, is sensitive to the passage of charged particles resulting from antiproton annihilation. This article describes the method used to reconstruct the annihilation location and to distinguish the annihilation signal from the cosmic ray background. Recent experimental results using this detector are outlined.

OPAL was one of the four experiments installed at the LEP particle accelerator from 1989 - 2000. OPAL's central tracking system consists of (in order of increasing radius) a silicon microvertex detector, a vertex detector, a jet chamber, and z-chambers. All the tracking detectors work by observing the ionization of atoms by charged particles passing by: when the atoms are ionized, electrons are knocked out of their atomic orbitals, and are then able to move freely in the detector. These ionization electrons are detected in the dirfferent parts of the tracking system. This piece is a prototype of the jet chambers

We present results for the charged-particle multiplicity distribution at mid-rapidity in Au - Au collisions at $\\sqrt{s_{_{NN}}}=130$ GeV measured with the PHENIX detector at RHIC. For the 5% most central collisions we find $dN_{ch}/d\\eta_{|\\eta=0} = 622 \\pm 1 (stat) \\pm 41 (syst)$. The results, analyzed as a function of centrality, show a steady rise of the particle density per participating nucleon with centrality.

Non-uniform distribution of the electric field outlined as double peak distortion (DPD) is considered for heavily irradiated silicon strip detectors, which were developed for the CERN-ATLAS semiconductor tracker. DPD originates from the non-uniform accumulation of electrons and holes from the bulk generated current that are captured by radiation induced defects: deep acceptors and donors with mid-gap energy levels. This corresponds to the formation of the low electric field region in the detector central part that consequently will delay charge collection. The electric field distributions at different reverse biases, fluences and detector operational temperatures are calculated using a one-dimensional Poisson equation as it was done earlier for pad detectors. It has been shown that due to the electric field focusing at the strips the DPD effect is more pronounced for strip detectors as compared to that in pad detectors. The double peak electric field distribution is evinced experimentally in current pulse res...

New Micromegas (Micro-mesh gaseous detectors) are being developed in view of the future physics projects planned by the COMPASS collaboration at CERN. Several major upgrades compared to present detectors are being studied: detectors standing five times higher luminosity with hadron beams, detection of beam particles (flux up to a few hundred of kHz/mm{sup 2}, 10 times larger than for the present detectors) with pixelized read-out in the central part, light and integrated electronics, and improved robustness. Studies were done with the present detectors moved in the beam, and two first pixelized prototypes are being tested with muon and hadron beams in real conditions at COMPASS. We present here this new project and report on two series of tests, with old detectors moved into the beam and with pixelized prototypes operated in real data taking condition with both muon and hadron beams.

A previous analysis of the X-700 Building Criticality Accident Alarm System (CAAS) showed that some of the building may not adequately be covered by the one building CAAS detector in its current location. This report compares the results of that analysis with a new analysis where the detector is in a different location. The new detector location (outside of the storage area in the center of the building--near column B-7) showed coverage for all points previously analyzed. The new centralized detector location reduces the distance and shielding between the source points and the detector. This explains the difference in the level of response when compared to the original (actual) detector location in the new annex west of the building.

Criteria for a high-resolution ..gamma..-ray system are discussed. Desirable properties are high resolution, good response function, and moderate solid angle so as to achieve not only double- but triple-coincidences with good statistics. The Berkeley High-Resolution Ball involved the first use of bismuth germanate (BGO) for anti-Compton shield for Ge detectors. The resulting compact shield permitted rather close packing of 21 detectors around a target. In addition, a small central BGO ball gives the total ..gamma..-ray energy and multiplicity, as well as the angular pattern of the ..gamma.. rays. The 21-detector array is nearly complete, and the central ball has been designed, but not yet constructed. First results taken with 9 detector modules are shown for the nucleus /sup 156/Er. The complex decay scheme indicates a transition from collective rotation (prolate shape) to single- particle states (possibly oblate) near spin 30 h, and has other interesting features.

"Scientists of the US CMS collaboration joined colleagues around the world in announcing today (February 28) that the heaviest piece of the Compact Muon Solenoid particle detector has begun the momentous journey into its experimental cavern 100 meters underground. A huge gantry crne is slowly lowering the CMS detector's preassembled central section into place in the Large Hadron Collider accelerator at CERN in Geneva, Switzerland." (1 page)

In this dissertation, a fast neutron flux-monitoring channel, which is based on the use of SiC semiconductor detectors is designed, modeled and experimentally evaluated as a power monitor for the Gas Turbine Modular Helium Reactors. A detailed mathematical model of the SiC diode detector and the electronic processing channel is developed using TRIM, MATLAB and PSpice simulation codes. The flux monitoring channel is tested at the OSU Research Reactor. The response of the SiC neutron-monitoring channel to neutrons is in close agreement to simulation results. Linearity of the channel response to thermal and fast neutron fluxes, pulse height spectrum of the channel, energy calibration of the channel and the detector degradation in a fast neutron flux are presented. Along with the model of the neutron monitoring channel, a Simulink model of the GT-MHR core has been developed to evaluate the power monitoring requirements for the GT-MHR that are most demanding for the SiC diode power monitoring system. The Simulink model is validated against a RELAP5 model of the GT-MHR. This dyanamic model is used to simulate reactor transients at the full power and at the start up, in order to identify the response time requirements of the GT-MHR. Based on the response time requirements that have been identified by the Simulink model and properties of the monitoring channel, several locations in the central reflector and the reactor cavity are identified to place the detector. The detector lifetime and dynamic range of the monitoring channel at the detector locations are calculated. The channel dynamic range in the GT-MHR central reflector covers four decades of the reactor power. However, the detector does not survive for a reactor refueling cycle in the central reflector. In the reactor cavity, the detector operates sufficiently long; however, the dynamic range of the channel is smaller than the dynamic range of the channel in the central reflector.

The detector solenoid for MICE surrounds a scintillating fiber tracker that is used to analyze the muon beam within the detector. There are two detector magnets for measuring the beam emittance entering and leaving the cooling channel that forms the central part of the experiment. The field in the region of the fiber detectors must be from 2.8 to 4 T and uniform to better than 1 percent over a volume that is 300 mm in diameter by 1000 mm long. The portion of the detector magnet that is around the uniform field section of the magnet consists of two short end coils and a long center coil. In addition, in the direction of the MICE cooling channel, there are two additional coils that are used to match the muon beam in the cooling channel to the beam required for the detectors. Each detector magnet module, with its five coils, will have a design stored-energy of about 4 MJ. Each detector magnet is designed to be cooled using three 1.5 W coolers. This report presents the mechanical and electrical parameters for the detector magnet system.

The Daya Bay Reactor Neutrino Experiment aims for the cleanest and the most precise measurement of the third neutrino mixing angle ?13, which will unlock the gateway of studying the CP violation in leptonic sector. The principle of the central Antineutrino Detectors is the inverse beta decay with coincidence detection of positron scitillation/annilation and neutron capture on Gadolinium. A 3-zone design was adopted for Antineutrino Detectors to minimize systematic uncertainties in detector target mass. Furthermore, an automated calibration system was developed to give a comprehensive and robust energy calibration with Ge, Co and AmC sources. In this talk, we will describe the design and construction of our Antineutrino Detectors. In addition, the performance of calibrations of our Antineutrino Detectors will be presented.

In order to fully exploit the physics opportunities of the Fermilab Tevatron in the Main Injector era, the D0 collaboration is building a major detector upgrade. All of the current D0 central and forward tracking detectors will be removed and replaced with a magnetic tracking system. Key components of this system include a silicon micro-vertex detector and a scintillating-fiber outer tracking detector surrounded by a 2 T superconducting solenoid. A preshower detector, based on scintillating tiles with fiber readout, is situated just outside the solenoid. Detailed simulations of this tracking system have been carried out. These studies show that the tracking and triggering capabilities of the upgraded tracking system will greatly enhance D0's ability to detect and study the top quark and will enable D0 to take advantage of the large amount of B physics available with the Main Injector. ((orig.))

Monte Carlo calculations have been made of the neutron flux and activation in the forward and barrel calorimeters in the L* detector and of the neutron flux in the central detector volume. In addition estimates of the charged particle and neutron background rates in the vicinity of the muon chambers has been determined. The Los Alamos National Laboratory code system LAHET and CINDER, 90 along with ISAJET and GEANT were used in these studies. The results indicate that neutron fluences as low as 2 {times} 10{sup 12} per SSC year can be achieved in the central volume. 6 refs., 3 figs., 2 tabs.

In this talk an overview of the ALICE transition radiation detector (TRD) is presented. In its final form the detector will consist of 540 individual detector modules with nearly 1.2 million readout channels. The TRD is part of the central barrel of ALICE and provides efficient electron identification for momenta above 1 GeV/c. In addition, it provides a fast trigger for charged particles with large transverse momentum. It is designed to operate in the very high multiplicity environment expected for heavy ion collisions at LHC.

The physics program and the design criteria for a Silicon Pad Detector at RHIC are reviewed. An end cap double sided readout detector configuration for RHIC is presented. Its performance as an on-line and off-line centrality tagging device is studied by means of simulations with Fritiof as the event generator. The results of an in-beam test of a prototype double-sided Si-detector are presented. Good signal-to-noise ratio are obtained with front junction and the resistive back side readout. Good separation between one and two minimum-ionizing particle signals is achieved.

In the ALICE experiment, the Low-Voltage Differential Signalling (LVDS) format is used for the transmission of trigger inputs from the detectors to the Central Trigger Processor (CTP), the L0 trigger outputs from Local Trigger Units (LTU) boards back to the detectors and the BUSY inputs from the sub-detectors to the CTP. ALICE has designed a set-up, called the LVDS transmission tester, that aims to measure various transmission quality parameters and the bit-error rate (BER) for long period runs in an automatic way. In this paper, this method is described and the conclusions from these tests for the ALICE LVDS cables are discussed

The ability to detect hydrogen gas leaks economically and with inherent safety is an important technology that could facilitate commercial acceptance of hydrogen fuel in various applications. In particular, hydrogen fueled passenger vehicles will require hydrogen leak detectors to signal the activation of safety devices such as shutoff valves, ventilating fans, alarms, etc. Such detectors may be required in several locations within a vehicle--wherever a leak could pose a safety hazard. It is therefore important that the detectors be very economical. This paper reports progress on the development of low-cost fiber-optic hydrogen detectors intended to meet the needs of a hydrogen-fueled passenger vehicle. In the design, the presence of hydrogen in air is sensed by a thin-film coating at the end of a polymer optical fiber. When the coating reacts reversibly with the hydrogen, its optical properties are changed. Light from a central electro-optic control unit is projected down the optical fiber where it is reflected from the sensor coating back to central optical detectors. A change in the reflected intensity indicates the presence of hydrogen. The fiber-optic detector offers inherent safety by removing all electrical power from the leak sites and offers reduced signal processing problems by minimizing electromagnetic interference. Critical detector performance requirements include high selectivity, response speed and durability as well as potential for low-cost production.

The authors have built and installed new electronics which brings the central shower max detector into the CDF Level-2 trigger. By matching a stiff track from the central fast track processor to an associated shower max cluster, this trigger improvement reduces the electron Level-2 cross section by approximately 50% while retaining greater than 85% of real electrons and allows the authors to lower their electron trigger threshold.

Following the discovery of W+, W- and Z0 particles, the carriers of nature's weak force, two CERN physicists were awarded the Nobel Prize in 1984. Carlo Rubbia , the Italian leader of the UA1 collaboration and driving force behind the conversion of CERN's Super Proton Synchrotron (SPS) into a machine capable of colliding protons and antiprotons, shared the prize with Simon van der Meer, whose technical virtuosity made the project possible. Interviews with Simon van der Meer and Carlo Rubbia.

In this paper we construct a string-like classical solution, the pion-string, in the linear sigma model. We then study the stability of the pion-string, and find that it is unstable in the parameter space allowed experimentally. We also speculate on the existance of an unstable eta-string, associated with spontaneous breakdown of the anomalous $U_A(1)$ symmetry in QCD at high temperatures. The implications of the pion and eta strings for cosmology and heavy ion collisions are briefly mentioned.

Correction is necessary to account for the detector size in clinical dosimetry of photon and electron beams. This correction is due to the absorbed dose gradient present in a finite-size detector. Further corrections are necessary when the detector and phantom materials are not the same. These corrections are due to the perturbation in the charged-particle fluence. Generally these corrections are applied to measurements along the central axis of the beam. Cross beam profile measurements, however, are not usually corrected for detector size. The ionization profile is also usually assumed to be equivalent to the absorbed dose profile. We have corrected the ionization chamber size effect by two approaches: extrapolation of measurements to zero detector size and deconvolution of measurements using a simple model for the detector response function. We have measured absorbed dose profiles to water using a small water-equivalent plastic scintillation detector. Film profile measurements were also studied. The ionization profile corrected for detector size and absorbed dose profile were not equal, probably due to loss of charged-particle equilibrium in the beam edges. For ionization chamber measurements, knowledge of the charged-particle spectrum is needed to convert ionization to absorbed dose to water. This is not necessary for relative absorbed dose measurements under charged-particle equilibrium. Film has been shown to be a straightforward and reliable method for cross beam profile measurements. PMID:2068227

UDP-galacturonic acid, the activated form of galacturonic acid (GalUA), is synthesized both de novo and by salvage pathways. The UDP-GalUA pyrophosphorylase gene involved in the salvage pathway has not been identified. Here we show that UDP-sugar pyrophosphorylase from Pisum sativum with a broad specificity has UDP-GalUA pyrophosphorylase activity. The enzyme catalyzed the formation of UDP-GalUA and pyrophosphate from GalUA 1-phosphate and UTP with an equilibrium constant value of 0.24. The recombinant UDP-sugar pyrophosphorylase had optimal pH of 6.0, and the apparent K(m) values for GalUA 1-phosphate, UTP, UDP-GalUA, and pyrophosphate were 2.27, 1.15, 0.70, and 1.26 mM, respectively. In the presence of inorganic pyrophosphatase, the recombinant enzyme produced UDP-GalUA in an 84% yield (based on the GalUA 1-phosphate substrate) on a preparative scale. Thus, this UDP-sugar pyrophosphorylase is useful for the highly efficient production of UDP-GalUA for studies on pectin biosynthesis. PMID:16581011

The BCD Silicon strip Vertex Detector is constructed of 10 identical central region modules and 18 similar forward region modules. This memo describes a method of assembling these modules from individual silicon wafers. Each wafer is fitted with associated front end electronics and cables and has been tested to insure that only good wafers reach the final assembly stage. 5 figs.

For the 1994 Tevatron collider run, CDF has upgraded the electron and photon trigger hardware to make use of shower position and size information from the central shower maximum detector. For electrons, the upgrade has resulted in a 50% reduction in backgrounds while retaining approximately 90% of the signal. The new trigger also eliminates the background to photon triggers from single-phototube discharge.

The proton-antiproton collider experiment UA2. From centre to outside: the central calorimeter, the recessed toroidal magnets (on temporary supports), and the recessed forward-backward detector structures with their drift chambers in front. (Annual Report 1982 p. 63, Fig. 5)

Event-by-event fluctuations in the multiplicities of charged particles and photons at SPS energies are discussed. Fluctuations are studied by controlling the centrality of the reaction and rapidity acceptance of the detectors. Results are also presented on the event-by-event study of correlations between the multiplicity of charged particles and photons to search for DCC-like signals.

The central problem in the case of face detectors is to build a face class model. We present a method for face class modeling in the eigenfaces space using a large-margin classifier like SVM. Two main issues are addressed: what is the required number of eigenfaces to achieve a good classification ra...

The Zeus experiment is being installed on the Hera electron-proton collider being built at the Desy laboratory in Hamburg. The high-beam crossover rate of the Hera machine will provide experience in data acquisition and triggering relevant to the environment of future accelerators such as the SSC. The Transputer-based data acquisition system for the Zeus central tracking detector is described.

CMS is a general purpose proton-proton detector designed to run at the highest luminosity at the LHC. It is also well adapted for studies at the initially lower luminosities. The main design goals of CMS are : a high performance muon system, a high resolution electromagnetic calorimeter, high quality central tracking, a hermetic hadron calorimeter.

A portable, hand-held apparatus is described for optically scanning indicia imprinted about a planar end face of an article having an outer wall surface, the apparatus comprising: a supporting frame; light detector means fixed to the frame for digitizing light patterns directed thereto; indexing means on the frame for engaging the planar end face and locating the end face in a preselected focal plane on the frame. The indexing means has an inner wall surface complementary to the article wall surface for disposition thereabout and terminates in an end portion beyond the planar end face. The inner wall surface has a radially inwardly extending shoulder spaced from the end portion and engageable with the planar end face; light means directed onto the preselected focal plane; optical means mounted on the frame about a central axis, the optical means being optically interposed between the indexing means and the light detector means for directing reflected light from the preselected focal plane to the light detector means and including a dove prism centrally aligned along the central axis; and means for selectively rotating the dove prism relative to the frame about the central axis to thereby rotate the image from the focal plane as transmitted to the light detector means.

Nonstatistical or intermittent'' fluctuations of charged particle multiplicities have been investigated at the CERN SPS with the WA80 multiplicity array for {sup 32}S+S and {sup 32}S+Au collisions of varying centrality. Within the phase space domain studied there is no evidence for intermittency in these collisions beyond that accounted for by FRITIOF filtered through a full detector simulation.

The time projection chamber is inserted inside the central detector of the DELPHI experiment. Gas is ionised in the chamber as a charged particle passes through, producing an electric signal from which the path of the particle can be found. DELPHI, which ran from 1989 to 2000 on the LEP accelerator, was primarily concerned with particle identification.

8 pages, 9 figures.-- ISI Article Identifier: 000251744500005 | The ATLAS Hadronic Tile Calorimeter detector (TileCal) is an iron-scintillating tiles sampling calorimeter designed to operate at the Large Hadron Collider accelerator at CERN. The central element of the back-end system of the TileCal d...

The Berkeley Mini-Collider, a heavy-ion collider being planned to provide uranium-uranium collisions at T/sub cm/ less than or equal to 4 GeV/nucleon, is described. The central physics to be studied at these energies and our early ideas for a collider detector are presented.

The ALICE experiment at the Large Hadron Collider (LHC) at CERN consists of a central barrel, a muon spectrometer and of additional detectors for trigger and event classification purposes. The low transverse momentum threshold of the central barrel gives ALICE a unique opportunity to study the low mass sector of central production at the LHC. I will report on first analysis results of meson production in double gap events in minimum-bias proton-proton collisions at sqrt{s} = 7 TeV, and will describe a dedicated double gap trigger for future data taking.

A one-coordinate gaseous detector of soft X-ray photons for wide-angle X-ray scattering (WAXS) studies is being developed. The detector operates in counting mode and is based on multi-stage Gas Electron Multiplier(GEM). Full size detector is assembled and has 67 degrees aperture with 350mm distance to the source, readout multi-strip structure with 2048 strips at 0.2mm pitch and is partially equipped with readout electronics in the central part. Main parameters of the detector have been measured with 8keV X-ray beam at VEPP-3 synchrotron ring. Spatial resolution of 470 um (FWHM) has been demonstrated that will allow to distinguish diffraction spots at 0.1 degrees.

Current generation neutrino telescopes cover an energy range from about 10 GeV to beyond $10^9$ GeV. IceCube sets the scale for future experiments to make improvements. Strategies for future upgrades will be discussed in three energy ranges. At the low-energy end, an infill detector to IceCube's DeepCore would add sensitivity in the energy range from a few to a few tens of GeV with the primary goal of measuring the neutrino mass hierarchy. In the central energy range of classical optical neutrino telescopes, next generation detectors are being pursued in the Mediterranean and at Lake Baikal. The KM3NeT detector in its full scale would establish a substantial increase in sensitivity over IceCube. At the highest energies, radio detectors in ice are among the most promising and pursued technologies to increase exposure at $10^9$ GeV by more than an order of magnitude compared to IceCube.

The ATLAS pixel detector consists of 1744 identical silicon pixel modules arranged in three barrel layers providing coverage for the central region, and three disk layers on either side of the primary interaction point providing coverage of the forward regions. Once deployed into the experiment, the detector will employ optical data transfer, with the requisite powering being provided by a complex system of commercial and custom-made power supplies. However, during normal performance and production tests in the laboratory, only single modules are operated and electrical readout is used. In addition, standard laboratory power supplies are used. In contrast to these normal tests, the data discussed here was obtained from a multi-module assembly which was powered and read out using production items: the optical data path, the final design power supply system using close to final services, and the Detector Control System (DCS). To demonstrate the functionality of the pixel detector system a stepwise transition wa...

Data are presented from the DRIFT-IId detector operated in the Boulby Underground Science Facility in England. A 0.8m3 fiducial volume, containing partial pressures of 30Torr CS2 and 10Torr CF4, was exposed for a duration of 47.4 live-time days with sufficient passive shielding to provide a neutron free environment within the detector. The nuclear recoil events seen are consistent with a remaining low-level background from the decay of radon daughters attached to the central cathode of the detector. However, charge from such events must drift across the entire width of the detector, and thus display large diffusion upon reaching the readout planes of the device. Exploiting this feature, it is shown to be possible to reject energy depositions from these Radon Progeny Recoil events while sti...

The Gaudi architecture and framework are designed to provide a common infrastructure and environment for simulation, filtering, reconstruction and analysis applications. In this context, a Detector Description Service was developed in LHCb in order to also provide easy and coherent access to the description of the experimental apparatus. This service centralizes every information about the detector, including geometry, materials, alignment, calibration, structure and controls. From the proof of concept given by the first functional implementation of this service late 2000, the Detector Description Service has grown and has become one of the major components of the LHCb software, shared among all applications, including simulation, reconstruction, analysis and visualization. We describe here the full and functional implementation of the service. We stress the easiness of customization and extension of the detector description by the user, on the seamless integration with condition databases in order to handle ...

We present the characterization of a positron emission tomograph for prostate imaging that centers a patient between a pair of external curved detector banks (ellipse: 45 cm minor, 70 cm major axis). The distance between detector banks adjusts to allow patient access and to position the detectors as closely as possible for maximum sensitivity with patients of various sizes. Each bank is composed of two axial rows of 20 HR+ block detectors for a total of 80 detectors in the camera. The individual detectors are angled in the transaxial plane to point towards the prostate to reduce resolution degradation in that region. The detectors are read out by modified HRRT data acquisition electronics. Compared to a standard whole-body PET camera, our dedicated-prostate camera has the same sensitivity and resolution, less background (less randoms and lower scatter fraction) and a lower cost. We have completed construction of the camera. Characterization data and reconstructed images of several phantoms are shown. Sensitivity of a point source in the center is 946 cps/mu Ci. Spatial resolution is 4 mm FWHM in the central region.

New Micromegas (Micro-mesh gaseous detectors) are being developed in view of the future physics projects planned by the COMPASS collaboration at CERN. Several major upgrades compared to present detectors are being studied: detectors standing five times higher luminosity with hadron beams, detection of beam particles (flux up to a few hundred of kHz/mm2, 10 times larger than for the present Micromegas detectors) with pixelized read-out in the central part, light and integrated electronics, and improved robustness. Two solutions for a reduction of the impact of discharges have been studied, with Micromegas detectors using resistive layers and using an additional GEM foil. The performance of such detectors has been measured during beam test periods. A large size prototype with nominal active area and pixelized read-out has been produced and installed in the COMPASS spectrometer in 2010. In 2011 prototypes featuring an additional GEM foil, as well as a resistive prototype, were tested in similar conditions and preliminary results from those detectors are very promising. We present here the project and report on its status, in particular the performance of large size prototypes with an additional GEM foil.

The objective of the present work was to examine fronto-central spindle frequency. A previously validated spindle detector, providing an electroencephalographic (EEG) amplitude independent spindle detection, was used to detect bilateral sleep spindles from sleep EEG recordings of ten healthy subjects with a time resolution of 0.33-s. A bilateral spindle detected centrally and frontopolarly simultaneously is called here a diffuse spindle. A bilateral spindle detected only frontopolarly or centrally at a given time is called a pure frontopolar and a pure central spindle, respectively. Spindle frequency was obtained with zero-padded discrete Fourier transform (DFT). Waveform phase angle of diffuse spindles was also examined. A total of 1230 diffuse spindles and 5316 pure central and 2595 pure...

Detectors from high-resistivity p-type silicon with multi guard rings structure located on the ohmic side have been investigated. The processed detectors were constructed with four p sup + -rings surrounding the central p sup + -pad. The n sup + -p junction opposite to the contact with rings had not any protection and was cut-through by chip scribing. Investigation of the potential distribution between the floating p sup + -rings has shown that the potential difference arises just after the depletion of the detector bulk and is accompanied by the detector leakage current saturation. The saturated current is mainly a leakage current flowing in a scribed periphery. Grounding of one of the p sup + -rings to collect the detector leakage current allows the separation of the bulk and the surface components of the current, which reduces the current of a central p sup + -pad contact down to tens nA/cm sup 2. A model based on the field effect in the gap between the neighboring p sup + -rings is proposed. The experimen...

The ESRF (European synchrotron radiation facility), with the help of the user community, is in the process of developing its long term strategy, covering the next 10 to 20 years. A central role in this strategy will be given to detector developments, since it is clear that the biggest possible improvement in performance is by increasing the overall detection capabilities. These improvements can be both quantitative, meaning more and larger detectors, and qualitative, meaning new detection concepts. This document gathers the abstracts and transparencies of most presentations of this workshop.

We review the status of the Lake Baikal Neutrino Experiment. The Neutrino Telescope NT200 has been operating since 1998 and has been upgraded to the 10 Mton detector NT200+ in 2005. We present selected astroparticle physics results from long-term operation of NT200. Also discussed are activities towards acoustic detection of UHE-energy neutrinos, and results of associated science activities. Preparation towards a km3-scale (Gigaton volume) detector in Lake Baikal is currently a central activity. As an important milestone, a km3-prototype string, based on completely new technology, has been installed and is operating together with NT200+ since April, 2008.

The authors present results of a simulation of the measurement of two-particle Bose-Einstein correlations in central Au-Au collisions with the PHOBOS detector at RHIC. This measurement is expected to yield information on the relevant time and distance scales in these collisions. As the space-time scale is directly connected with the equation of state governing the evolution of the particle source, this information will be essential in understanding the physics of nucleus-nucleus collisions at RHIC energies. The authors demonstrate that the PHOBOS detector has sufficient resolution and acceptance to distinguish a variety of physics scenarios.

Detectors at future e+e- collider need special calorimeters in the very forward region for a fast estimate and precise measurement of the luminosity, to improve the hermeticity and mask the central tracking detectors from backscattered particles. Design optimized for the ILC collider using Monte Carlo simulations is presented. Sensor prototypes have been produced and dedicated FE ASICs have been developed and tested. For the first time, sensors have been connected to the front-end and ADC ASICs and tested in an electron beam. Results on the performance are discussed.

The transition radiation detector (TRD) for the ALICE experiment at the Large Hadron Collider at CERN will provide electron identification in the central barrel at momenta in excess of 1GeV/c as well as fast triggering (6{mu}s) capability. It consists of 540 gas detectors with an active area of roughly 750m{sup 2} and almost 1.2 million readout channels. The TRD detector control system (DCS) back-end is fully implemented as a detector oriented hierarchy of objects behaving as finite state machines. PVSS II is used in the supervisory layer. Software communications to the hardware is realized by means of a distributed information management server running on an embedded Linux system pool with about 550 servers. TRD DCS controls and monitors 75k FEE chips, several hundred low and high voltage channels, gas and cooling. We give an overview of the commissioning of the TRD detector control system and highlight the operation of 2 TRD supermodules during a continuous 2-weeks cosmic data run with the ALICE detector. Finally, we report on the preparation for the first collisions in ALICE with the startup of LHC mid of 2008.

The GERmanium Detector Array (GERDA) is an ultra-low background experiment under construction at Laboratori Nazionali del Gran Sasso. GERDA will search for {sup 76}Ge neutrinoless double beta decay with an aim for 100-fold reduction in background compared to predecessor experiments. This ambition necessitates innovative design approaches, strict selection of low-radioactivity materials, and novel techniques for active background suppression. The core feature of GERDA is its array of germanium detectors for ionizing radiation, which are enriched in {sup 76}Ge. Germanium detectors are the central theme of this dissertation. The first part describes the implementation, testing, and optimisation of Monte Carlo simulations of germanium spectrometers, intensively involved in the selection of low-radioactivity materials. The simulations are essential for evaluations of the gamma ray measurements. The second part concerns the development and validation of an active background suppression technique based on germanium detector signal shape analysis. This was performed for the first time using a BEGe-type detector, which features a small read-out electrode. As a result of this work, BEGe is now one of the two detector technologies included in research and development for the second phase of the GERDA experiment. A suppression of major GERDA backgrounds is demonstrated, with (0.93{+-}0.08)% survival probability for events from {sup 60}Co, (21{+-}3)% for {sup 226}Ra, and (40{+-}2)% for {sup 228}Th. The acceptance of {sup 228}Th double escape events, which are analogous to double beta decay, was kept at (89{+-}1)%. (orig.)

Triple Charge Division (TCD) centroid finding method that uses modified pattern of Backgammon Shape Cathode (MBSC) is introduced for medium range length position sensitive detectors with optimum numbers of cathode segments. MBSC pattern has three separated areas and uses saw tooth like insulator gaps for separating the areas. Side areas of the MBSC pattern are severed by a central common area. Size of the central area is twice of the size of both sides. Whereas central area is the widest area among three, both sides` areas have the main role in position sensing. With the same resolution and linearity, active region of original Backgammon pattern increases twice by using MBSC pattern, and with the same length, linearity of TCD centroid finding is much better than Backgammon charge division readout method. Linearity prediction of TCD centroid finding and experimental results conducted us to find an optimum truncation of the apices of MBCS pattern in the central area. The TCD centroid finding has an especial readout method since charges must be collected from two segments in both sides and from three segments in the central area of MBSC pattern. The so called Graded Charge Division (GCD) is the especial readout method for TCD. The GCD readout is a combination of the charge division readout and sequence grading of serial segments. Position sensing with TCD centroid finding and GCD readout were done by two sizes MBSC patterns (200mm and 80mm) and Spatial resolution about 1% of the detector length is achieved.

We present a preliminary measurement of the central inclusive jet cross section using a successive combination algorithm based on relative transverse momenta (k{perpendicular}) for jet reconstruction. We analyze a 87.3 pb{sup -1} data sample collected by the D0 detector at the Fermilab Tevatron p{bar p} Collider during 1994-1995. The cross section, reported as a function of transverse momentum (p{sub T} > 60 GeV) in the central region of pseudo-rapidity (|{eta}| < 0.5), is in reasonable agreement with next-to-leading order QCD predictions. This is the first jet production measurement in a hadron collider using a successive combination type of jet algorithm.

Presently the D/null/ detector has three big toroidal magnets; one Central Toroid (CF) and two End Wall Toroids (EF). The EF toroids have central openings 72'' x 72''. Originally, this opening was meant for possible future end-plug calorimeters. Instead we are now designing Small Angle Muon Spectrometer (SAMUS) for the opening. The major component will be built at Serpukhov. The design of the toroid magnets and its magnetic field calculations is being done by exchanging information between Serpukhov and Fermilab. 2 refs., 4 figs., 1 tab.

Black hole (BH)--torus systems are promising candidates for the central engine of gamma-ray bursts (GRBs), and also possible outcomes of the collapse of supermassive stars to supermassive black holes (SMBHs). By three-dimensional general relativistic numerical simulations, we show that an $m=1$ nonaxisymmetric instability grows for a wide range of self-gravitating tori orbiting BHs. The resulting nonaxisymmetric structure persists for a timescale much longer than the dynamical one, becoming a strong emitter of large amplitude, quasiperiodic gravitational waves. Our results indicate that both, the central engine of GRBs and newly formed SMBHs, can be strong gravitational wave sources observable by forthcoming ground-based and spacecraft detectors.

The performance of the spherical drift chamber of the BUGS IV (Bristol university gas scintillator) cosmic ray detector is presented. The 1 m radius spherical chamber employed Ar-N{sub 2} gas scintillation, gas-proportional scintillation, and electron drift timing to provide charge, energy, and pathlength correction information. The details of the scintillation and drift processes are presented and the combination of these techniques in the BUGS IV central drift chamber are discussed. The performance of a recent exposure of the BUGS IV central spherical chamber to relativistic cosmic ray iron nuclei is presented. It is shown that the chamber provided pathlength corrections to all elements of this multi-detector experiment with relative uncertainties of less than 2% for 90% of all impact parameters. The maximum uncertainty for the largest impact parameter events remained less than 5%. Model drift waveforms are derived and shown to be in excellent agreement with the observed data. (orig.). 21 refs.

The DØ calorimeter at Fermilab is a sampling calorimeter measuring the energy of particles produced in high energy proton-antiproton collisions. A set of accurate sampling weights is of significant importance to DØ research activity. The objective of this work was to obtain a set of optimized sampling weights for the DØ central calorimeter, the Inter-Cryostat Detector (ICD), the Central Calorimeter Massless Gap (CCMG), and the End Calorimeter Massless Gap (ECMG). The foundation of the optimization method is that, in high energy physics, the ratio of energy E and the corresponding momentum P of a particle is approximately 1, in units where speed of light is c = 1. The energy distributions in different layers of the calorimeter is different, there are also differences among different calorimeter channels. A computational model, based on those differences, was formulated to calculate the energy E, and the momentum P was obtained through the detectors' precision tracker measuremen...

The production and decay of the &phis; meson in relativistic heavy ion collisions is of considerable interest. An enhanced &phis; meson yield has been suggested as a signature for the formation of a deconfined phase. Furthermore, medium modifications of &phis; meson properties might be related to the expected chiral phase transition. In the year of 2001, the PHENIX experiment at RHIC has measured Au-Au collisions at SNN = 200 GeV. The trajectories and momenta of charged particles are measured with the PHENIX central arm tracking detectors. The additional velocity measurements from the high resolution Time-of-Flight detector as well as the broader acceptance Electromagnetic Calorimeter give PHENIX excellent capabilities to identify charged kaons. An excellent pair mass resolution of approximately 1.3 MeV was achieved for the combined systems. Results on the transverse mass distribution, the centrality dependence of the yield, inverse slope parameter, and the resonance and width of &phis; are...

The Large Hadron Collider at CERN will collide protons at \\sqrtS = 14TeV and lead ions at \\sqrt$\\S_{NN}$. The study of heavy ion collisions is an integral part of the physics program of the Compact Muon Solenoid (CMS). Central heavy ion events at LHC energies are expected to produce a multiplicity of up to 3500 charged particles per unit of rapidity. The CMS detector features a large acceptance and high resolution silicon tracker consisting of pixel and strip detector layers. We describe the algorithms used for pattern recognition in the very high track density environment of heavy ion collisions. Detailed studies using the full detector simulation and reconstruction are presented and achieved reconstruction efficiencies, fake rates and resolutions are discussed.

The performance of a synthetic diamond X-ray detector during typical clinical beam characterisation procedures was compared to the performance of standard clinical detectors; this diamond detector used a single crystal diamond film synthesised using chemical vapour deposition as its sensitive element. Measurements were performed using 6 MV photons from a Varian 600C linear accelerator. The procedures measured the dose profile with depth along the central axis in a phantom (tissue maximum ratio) for a 10 x 10 cm^2 field, variation in dose at the isocentre with field size (output factor), and dose profile across and beyond the X-ray beam (off-axis ratio) for 10 x 10 cm^2 and 1 x 1 cm^2 fields. Tissue maximum ratio values were within 0.8% of the values from a standard ion chamber, over a dept...

The central component of the ATLAS Inner Tracker is the pixel detector. It consists of three barrel layers and three disk-layers in the end-caps in both forward directions. The innermost barrel layer is mounted at a distance of about 5 cm from the interaction region. With its very high granularity, truly two-dimensional hit information, and fast readout it is well suited to cope with the high densities of charged tracks, expected this close to the interaction region. The huge number of readout channels necessitates a very complex services infrastructure for powering, readout and safety. After a description of the pixel detector and its services infrastructure, key results from the system test at CERN are presented. Furthermore the noise performance of the pixel detector, crucial for high tracking and vertexing efficiencies, is studied. Measurements of the single-channel random noise are presented together with studies of common mode noise and measurements of the noise occupancy using a random trigger generator. (orig.)

The pulsed high-flux neutron source ESS, in synergy with advanced neutron optics and spectrometers, will require imaging detectors with better resolution and faster response than presently available. Thus in this work, which is part of a project of the Hahn-Meitner-Institut (HMI), a novel neutron detector has been developed. In the central detector plane a composite foil converter ( sup 1 sup 5 sup 7 Gd/CsI) is located, emitting, after neutron capture and subsequent emission of conversion electrons, a detectable cluster of low-energy electrons. In two adjacent low-pressure gas gaps, sandwiched between fourfold segmented micro-strip gas chamber (MSGC) plates on each side, the clusters are pre-amplified in parallel-plate mode and further in the strong alternating fields between the micro-strips. The advanced micro-strip design is made in multilayer technology on a robust glass substrate. Two closely spaced electrode planes are used for two-dimensional position readout. The expected position resolution is 0.1 - ...

Within a Collaboration Agreement between INFN and CAS (Chinese Academy of Science), the ARGO-YBJ experiment is completely installed at the YangBaJing Cosmic Ray Laboratory (4300 m a.s.l., Tibet, P.R. China). ARGO-YBJ is a plane detector, with a total detection area of {approx}6500 m{sup 2}, made of Resistive Plate Chambers (RPCs) which provide a detailed space-time picture of the charged component of the extensive air showers. At present the detector is completely mounted and the central carpet of 5800 m{sup 2} is operating under a multiplicity trigger N{sub pad}{>=}20, the trigger rate is about 3.5 kHz and the data flow is 5 MB/s. A 0.5 cm lead converter will be mounted on the detector in summer 2007.

Pit commissioning activities The last 4 months have seen various major achievements in hardware commissioning, global data taking, readiness of the DPGs to deal with LHC data flows and alignment and calibration workflows. Since February, the global commissioning has been characterized on the one side by more and more of the final CMS detector becoming available for global readout and triggering and on the other side by consolidation of many of the central software infrastructure and of most of the services infrastructure. The reliability of services like cooling, power, gas has markedly improved with respect to what we observed in the second half of 2007.   Of particular note are the delivery of all low voltage power supplies, the commissioning of the final power distribution, the progressive commissioning ( still ongoing)  of the Detector Safety System and of the associated DCS early warning and alarm system. On the detector side, while already we are used to seeing all of HCAL being exe...

A Time Projection Chamber (TPC) is a candidate for the central tracker of the ILC detectors. TPCs based on Micropattern Gaseous Detectors (MPGD), described in the ILC Reference Design Report, have dimensions of 2.8–4m in diameter and 3–4.6m in length. They are to provide 200 space points with pad readout, along a particle track with the Formula Not Shown spatial resolution of Formula Not Shown per row or better. The momentum resolution of Formula Not Shown is envisaged in the magnetic field of 3–4T. To realize the excellent space point resolution of Formula Not Shown , a TPC with MPGD readout instead of the Multiwire Proportional Chamber (MWPC) readout is needed [1]. The MPGD under consideration are Gas Electron Multiplier (GEM) and Micromesh Gas detector (Micromega...

Tau leptons play a central role in the LHC physics programme, in particular as an important signature in many Higgs boson and Supersymmetry searches. They are further used in Standard Model electroweak measurements, as well as detector related studies like the determination of the missing transverse energy scale. Copious backgrounds from QCD processes call for both efficient identification of hadronically decaying tau leptons, as well as large fake rejection. A solid understanding of the combined performance of the calorimeter and tracking detectors is also required. We present the current status of the tau reconstruction, energy calibration and identification with the ATLAS detector at the LHC. Identification efficiencies are measured in Wtaunu events in data and compared with predictions from Monte Carlo simulations, whereas the misidentification probabilities of QCD jets and electrons are determined from various jet-enriched data samples and from Zee events, respectively. The tau energy scale calibration i...

The ATLAS Transition Radiation Tracker (TRT) is the outermost of the three sub-systems of the ATLAS Inner Detector at the Large Hadron Collider (LHC) at CERN. It consists of close to 300000 thin-wall drift tubes (straws) providing on average 30 two-dimensional space points with 130 ?m resolution for charged particle tracks with |?| < 2 and pT > 0.5 GeV/c. The TRT is immersed in a 2 T magnetic field generated by the central solenoid, significantly contributing together with the other two Inner Detector sub-systems to the particle momentum reconstruction. Along with continuous tracking, it provides particle identification capability through the detection of transition radiation X-ray photons. This talk will describe the operational experience gained with the ATLAS TRT detector during the commissioning with cosmic rays and operation with the first proton-proton collision data at 900 GeV and 7 TeV center-of-mass energy.

The status of the MEGA experiment is described. It is a search for the decay {mu} {r arrow} e{gamma} with a branching ratio sensitivity of approximately 10{sup {minus}13}. The observation of this decay would indicate the existence of physics outside the standard model of electroweak interactions. The experiment employs highly modular, fast detectors, state-of-the-art electronics, and a staged trigger with on-line filters. The detectors are contained in a 1.5 T solenoidal field produced by a superconducting magnet. Positrons are confined to the central region and are measured by a set of thin MWPCs. Photons are measured by one of four layers of pair spectrometers in the outer region. Most aspects of the detector design have been validated in engineering runs; data taking will begin in 1990 with most of the electron arm and one pair spectrometer layer installed. 5 refs., 4 figs.

The ATLAS experiment is being assembeled as a general purpose particle detector to exploit the physics discovery potential of the Large Hadron Collider. The SemiConductor Tracker (SCT), one of the central subsystems of ATLAS, requires alignment of O(10?m) for good performance. The alignment program consists of a set of proceedures to establish the location of detector elements. This includes optimised design and construction prior to operation. This thesis describes Electronic Speckle Pattern Interferometry (ESPI), a technique used to measure deformation at the micron level which has been applied to SCT components during design and prototype development. ESPI creates contour maps of objects under study, helping a qualitative understanding of object behaviour as well as providing measurements. ESPI measurements of the thermal deformation of SCT detector modules are presented. A modified ESPI interferometer was developed to create contours of vibration amplitude. Tests were performed on well-understood objects...

A bend detector is described for use on a pipeline pig assembly; the pipeline pig assembly comprising a front pig element and a rear pig element pivotally connected to each other by the bend detector, the front pig element having a longitudinally disposed housing with means for driving the pipeline assembly by the flow of a fluid through a pipeline system. The rear pig element has a longitudinally disposed housing with means for axially supporting the housing in the pipeline system. The detector includes a means for determining the distance traversed by the pipeline pig assembly through the pipeline system. The bend detector comprises a universal joint having a pair of yoke members being pivotally interconnected to a central member so as to oscillate about a pair of mutually perpendicular axes lying in a plane generally perpendicular to the axis of the pipeline, each of the yoke members having a yoke and a collar. The detector also includes a means for mounting each collar to the front pig element and the rear pig element, respectively, the central member being provided with a substantially longitudinal bore for receiving a hollow sleeve, a central opening in each collar thereby forming an axially aligned passageway with the hollow sleeve. A cable is received in the passageway and has its rear end anchored to the mounting means of the rear pig element, the forward end of the cable connected to an actuator shaft for a stylus for recording a bend along the pipeline system, whereby when the pig assembly traverses a bend. The front pig element pivots with respect to the rear pig element thereby pivoting the sleeve relative to the passageway and thereby exerting a pull on the cable causing the actuator shaft to move longitudinally rearward; thereby indicating the location and degree of the bend.

This report describes the activities of the Heavy Ion Physics Group at the University of California, Riverside from October 1, 1991 to September 30, 1992. During this period, the program focused on particle production at AGS energies, and correlation studies at the Bevalac in nucleus-nucleus central collisions. As part of the PHENIX collaboration, contributions were made to the Preliminary Conceptual Design Report (pCDR), and work on a RHIC silicon microstrip detector R&D project was performed.

The Zeus experiment is being installed on the Hera electron-proton collider being built at the Desy laboratory in Hamburg. The high beam crossover rate of the Hera machine will provide experience in data acquisition and triggering relevant to the SSC environment. This paper describes the Transputer based data acquisition for the Zeus Central Tracking Detector, and outlines some proposed development work on the use of parallel processing techniques in this field.

We present the first measurement of fluctuations from event to event in the production of strange particles in collisions of heavy nuclei. The ratio of charged kaons to charged pions is determined for individual central Pb+Pb collisions. After accounting for the fluctuations due to detector resolution and finite number statistics we derive an upper limit on genuine non-statistical fluctuations, perhaps related to a first or second order QCD phase transition. Such fluctuations are shown to be very small.

The LHC experiments provide an unprecedented coverage in pseudo-rapidity. This advantage and high LHC luminosity allow for broad studies of central exclusive production (CEP) processes such as exclusive production of ¡, di-leptons, di-photons and di-jets. Finally, with the proposed near beam detectors (FP420 and FP220) the exclusive Higgs and SUSY states will be also accesible. The discussion is focused on the CMS programme, as both CMS and ATLAS have similar kinematical coverage and may perform similar studies.

An automated gas chromatograph/electron capture detector (GC/ECD) system was developed to monitor the concentration of HCFC-22 in the urban atmosphere at intervals of 90 min. By using two columns in series we avoided the use of cryogen and dryer for preconcentration or sample drying. Oxygen was doped into the N2 carrier gas to sensitize the ECD. Serial measurements of atmospheric HCFC-22 concentration were attempted in the central area of Tokyo.   

The Fluorescence Detector of the Pierre Auger Observatory uses the atmosphere as a huge calorimeter that needs continuous monitoring to ensure unbiased physics results. The Central Laser Facility (CLF), a calibrated laser source located near the center of the observatory, is used to measure the light attenuation due to aerosols, highly variable even on time scales of 1h. Two independent, fully compatible procedures based on the analysis of CLF vertical events have been developed. Five years of hourly aerosol characterization are provided.

Fully loaded the Central Barrel will weigh 3000 tonnes. Those feet have tosupport this weight. Therefore they are made of 120 mm thick steel plates.To guarantee a maximum coverage for the muon detctor they will house a muon detector just benaeth the top plate. Weight of 1 foot is 35 tonnes.Its height is 3.5 m and it is 2.5 m large

A scheme for time resolved X-ray detection with potentially better than 10 fs time resolution is proposed. The central idea is to use intense fs-laser pulses to depopulate the valence band of a semiconductor and thus switch the absorption of X-rays, monochromatized to just below an absorption edge of the material. The effect can be used as a fast shutter and as a fast detector by recording secondary processes such as X-ray fluorescence or resonant Raman scattering.

A novel large input range source-follower based filter architecture is proposed offering a increased 1-dB compression point, without increased power consumption. An alternative feedback mechanism enables single-ended use and simplifies the bias scheme. Simulation has confirmed a 250MHz second order filter stage consuming 40uA @ 1.2V supply in a 0.13um CMOS technology with 1-dB compression point at a differential peak to peak input amplitude of 1.4V, more than doubling the input range of previous implementations with similar power dissipation.   

CERN in Focus 1ère édition. Le Service Audiovisuel vous propose un panorama des dernières vidéos tournées au CERN. En effet, toutes les six semaines, nous vous présenterons l'ensemble des activités, du démarrage du LHC à la grille de calcul, en passant par les différentes expériences. Au sommaire de cette édition, la visite du premier ministre de Malte, CMS et la derniere descente du YE-1 Le depart des aimants UA1 pour le Japon La mise en marche des secteurs 4 et 5 Et enfin, ATLAS et la descente... BREVES Dernieres soudures LHC Derniers boulonnages LHC College leman Appel a candidature Open Day

The hadron calorimeter for the UA1 experiment at the CERN SPS proton- antiproton collider consists of a lead-scintillator sandwich plus an iron-scintillator sandwich with wavelength shifter readout. The authors have tested prototype modules in muon and hadron beams in the momentum range from 0.7 to 90 GeV/c. For several angles of incidence, they have studied the uniformity of the response to hadrons as a function of position. This has included regions where there is reduced sensitivity due to mechanical constraints and the presence of the wavelength shifter readout. The response, resolution and degree of shower containment were measured as a function of incident momentum.

The Transition Radiation Detector (TRD) is composed of 18 super modules arranged in a barrel geometry in the central part of the ALICE detector. Comprising a total of 540 large-area drift chambers mounted in six layers, it offers almost 1.2 million readout channels on a total area of roughly 750 m{sup 2}. The TRD trigger performs online tracking and electron identification in the challenging heavy ion collisions environment (as well as in pp collisions) within only 6 {mu}s after the interaction and thus requires excellent position resolution and pion rejection capability. The first of the 18 TRD super modules was installed in the ALICE central barrel in October 2006. Two more super modules are scheduled for installation in May 2007, the remaining part being completed during 2008. We will highlight the detector performance of the TRD, including momentum dependence of position resolution, angle resolution and electron identification performance as measured during beam tests. An overview on the commissioning of the detector with cosmic events will be given, focussing on the preparation for first beam in autumn 2007, with the start-up of the LHC. (orig.)

The D0 detector has recently undergone a major upgrade to maximize its potential to fully exploit Run II at the Tevatron 2 TeV proton-antiproton collider. The upgrade includes a completely new central tracking system with an outer scintillating fiber tracker and an inner silicon vertex detector. This thesis describes the development of the software to ''unpack'' the raw data from the central tracking detectors into a useful form, and the development of the Level 3 trigger algorithms to cluster the hit information from these detectors. One of the many areas of physics that is being studied by the D0 experiment is the physics of B mesons, particularly that involving CP violation. The second part of the thesis details a constrained mass fitting tool written to aid the reconstruction of B particles, and a Monte Carlo study into measuring the lifetime of B{sup +} and B{sup 0} mesons. This thesis lays the foundations for the means by which physics is extracted from the vast amount of Tevatron data--the trigger--and illustrates how analyses will proceed through the key reconstruction of heavy quarks.

The ALICE trigger system (TRG) consists of a Central Trigger Processor (CTP) and up to 24 Local Trigger Units (LTU) for each sub-detector. The CTP receives and processes trigger signals from trigger detectors and the outputs from the CTP are 3 levels of hardware triggers: L0, L1 and L2. The 24 sub-detectors are dynamically partitioned in up to 6 independent clusters. The trigger information is propagated through the LTUs to the Front-end electronics (FEE) of each sub-detector via LVDS cables and optical fibres. The trigger information sent from LTU to FEE can be monitored online for possible errors using the newly developed TTCit board. After testing and commissioning of the trigger system itself on the surface, the ALICE trigger electronics has been installed and tested in the experimental cavern with appropriate ALICE experimental software. Testing the Alice trigger system with detectors on the surface and in the experimental cavern in parallel is progressing very well. Currently one setup is used for testi...

The Compact Muon Solenoid (CMS) experiment at CERN is a multi-purpose experiment designed to exploit the physics of proton-proton collisions at the Large Hadron Collider collision energy (14TeV at centre of mass) over the full range of expected luminosities (up to 1034cm-2s-1). The CMS detector control system (DCS) ensures a safe, correct and efficient operation of the detector so that high quality physics data can be recorded. The system is also required to operate the detector with a small crew of experts who can take care of the maintenance of its software and hardware infrastructure. The subsystems size sum up to more than a million parameters that need to be supervised by the DCS. A cluster of roughly 100 servers is used to provide the required processing resources. A scalable approach has been chosen factorizing the DCS system as much as possible. CMS DCS has made clear a division between its computing resources and functionality by creating a computing framework allowing plugging in of functional components. DCS components are developed by the subsystems expert groups while the computing infrastructure is developed centrally. To ensure the correct operation of the detector, DCS organizes the communication between the accelerator and the experiment systems making sure that the detector is in a safe state during hazardous situations and is fully operational when stable conditions are present. This paper describes the current status of the CMS DCS focusing on operational aspects and the role of DCS in this communication.

A 3 year long R and D activity on triple gas electron multiplier (GEM) detectors is reported. This activity was made in the framework of the LHCb experiment in order to find the technology to instrument the central region of the first muon station (M1R1) where a high particle rate is expected. Detector geometry, gas mixture and electric field configuration have been optimized in order to achieve the performance required by the experiment. The use of a very fast, CF4 based, gas mixture provides a time resolution of about 4.5ns (r.m.s.) with a single chamber with gain less than 104. In addition, an optimized gain sharing between the three GEMs allows to keep the discharge probability per incident hadron below 10-12. The average number of firing pads per crossing particle have been found to be lower than 1.2. In a global aging test two detectors were exposed to a dose rate of 16Gy/h. Each detector integrated about 2C/cm2 equivalent to more than 10 years of operation at LHCb. Good aging properties were measured. These results make the triple-GEM detectors a good solution for M1R1 and, in general, for a fast trigger in the presence of a high rate of charged particles.

Data are presented from the DRIFT-IId detector operated in the Boulby Underground Science Facility in England. A 0.8 m3 fiducial volume, containing partial pressures of 30 Torr CS2 and 10 Torr CF4, was exposed for a duration of 47.4 live-time days with sufficient passive shielding to provide a neutron free environment within the detector. The nuclear recoil events seen are consistent with a remaining low-level background from the decay of radon daughters attached to the central cathode of the detector. However, charge from such events must drift across the entire width of the detector, and thus display large diffusion upon reaching the readout planes of the device. Exploiting this feature, it is shown to be possible to reject energy depositions from these Radon Progeny Recoil events while still retaining sensitivity to fiducial-volume nuclear recoil events. The response of the detector is then interpreted, using the F nuclei content of the gas, in terms of sensitivity to proton spin-dependent WIMP-nucleon interactions, displaying a minimum in sensitivity cross section at 1.8 pb for a WIMP mass of 100 GeV/c2. This sensitivity was achieved without compromising the direction sensitivity of DRIFT.

In the summer of 2007, the GLD concept study group, whose membership was largely based in Asia, and the LDC concept study group, which was mostly based in Europe with a strong north american membership, joined forces to produce a single Letter of Intent for a detector at the International Linear Collider, and formed the ILD concept group. Both the GLD and LDC concepts used the particle flow algorithm for jet reconstruction and a TPC for the central tracker. The basic parameters of the two concepts such as the size of the detector and the strength of the solenoid field, however, were quite different and had to be unified in order to write this letter of intent for ILD. Also, other critical details such as the interaction region design had to be unified. This was a non-trivial task, neither politically nor sociologically. The newly-formed concept study group, the ILD group, created a management team and engaged in intense studies to define the ILD detector concept by scientifically optimising the detector designs. The process has worked remarkably well, and we present here the outcome of this study as well as the large amount of studies that preceded separately by the two older concept groups. The ILD detector concept is now well defined, even though some technology choices are still open. One of the merits of unifying the detector concepts was that it revitalised the studies on physics performance and detector designs. We believe that the level of sophistication of the simulation and physics analyses has reached a high degree of sophistication for a detector group at this stage. This was achieved through collaboration and competition, and is the result of a productive learning process. The unification had also positive effects on the subdetector R and D efforts. Most R and D on detector technologies relevant to the GLD and LDC groups is being performed within the framework of detector R and D collaborations such as LCTPC, SiLC, CALICE, and FCAL which pursue their own goals of detector technology development. Members of the detector concept groups participate in the R and D collaborations and make sure that the detector technologies are successfully applied to the detector concept designs. By the creation of the ILD concept group, the application efforts became more focused. Currently, the ILD management includes subdetector contacts who are also key members of the detector R and D collaborations. This scheme is working efficiently such that we can finish basic R and D in time for the Technical Design Report which is envisaged around 2012. Overall, the ILD group structure is efficient while keeping exibility and openness. Even though we are still short on person power and funding at this time, we believe that we are well positioned to successfully complete a technical design for a detector at the International Linear Collider. The ILD group is firmly committed to the ILD project. (orig.)

The Fermilab Collider Detector Facility (CDF) is a large detector system designed to study anti pp collisions at very high center of mass energies. The central detector for the CDF shown employs a large axial magnetic field volume instrumented with a central tracking chamber composed of multiple layers of cylindrical drift chambers and a pair of intermediate tracking chambers. The purpose of this system is to determine the trajectories, sign of electric charge, and momenta of charged particles produced with polar angles between 10 and 170 degrees. The magnetic field volume required for tracking is approximately 3.5 m long an 3 m in diameter. To provide the desired ..delta..p/sub T/p/sub T/ less than or equal to 1.5% at 50 GeV/c using drift chambers with approx. 200..mu.. resolution the field inside this volume should be 1.5 T. The field should be as uniform as is practical to simplify both track finding and the reconstruction of particle trajectories with the drift chambers. Such a field can be produced by a cylindrical current sheet solenoid with a uniform current density of 1.2 x 10/sup 6/ A/m (1200 A/mm) surrounded by an iron return yoke. For practical coils and return yokes, both central electromagnetic and central hadronic calorimetry must be located outside the coil of the magnet. This geometry requires that the coil and the cryostat be thin both in physical thickness and in radiation and absorption lengths. This dual requirement of high linear current density and minimal coil thickness can only be satisfied using superconducting technology. In this report we describe the design for an indirectly cooled superconducting solenoid to meet the requirements of the Fermilab CDF. The components of the magnet system are discussed in the following chapters, with a summary of parameters listed in Appendix A.

BTeV is a new Fermilab beauty and charm experiment designed to operate in the CZero region of the Tevatron collider. Critical to the success of BTeV is its pixel detector. The unique features of this pixel detector include its proximity to the beam, its operation with a beam crossing time of 132 ns, and the need for the detector information to be read out quickly enough to be used for the lowest level trigger. This talk presents an overview of the pixel detector design, giving the motivations for the technical choices made. The status of the current R&D on detector components is also reviewed. Additional Pixel 2002 talks on the BTeV pixel detector are given by Dave Christian[1], Mayling Wong[2], and Sergio Zimmermann[3]. Table 1 gives a selection of pixel detector parameters for the ALICE, ATLAS, BTeV, and CMS experiments. Comparing the progression of this table, which I have been updating for the last several years, has shown a convergence of specifications. Nevertheless, significant differences endure. The BTeV data-driven readout, horizontal and vertical position resolution better than 9 {micro}m with the {+-} 300 mr forward acceptance, and positioning in vacuum and as close as 6 mm from the circulating beams remain unique. These features are driven by the physics goals of the BTeV experiment. Table 2 demonstrates that the vertex trigger performance made possible by these features is requisite for a very large fraction of the B meson decay physics which is so central to the motivation for BTeV. For most of the physics quantities of interest listed in the table, the vertex trigger is essential. The performance of the BTeV pixel detector may be summarized by looking at particular physics examples; e.g., the B{sub s} meson decay B{sub s} {yields} D{sub s}{sup -} K{sup +}. For that decay, studies using GEANT3 simulations provide quantitative measures of performance. For example, the separation between the B{sub s} decay point and the primary proton-antiproton interaction can be measured with an rms uncertainty of 138 {micro}m. This, with the uncertainty in the decay vertex position, leads to an uncertainty of the B{sub s} proper decay time of 46 fs. Even if the parameter x{sub s} equals 25 (where the current lower limit on x{sub s} is about 15), the corresponding relevant proper time is 400 fs. So, the detector resolution is more than adequate to make an excellent measurement of this parameter.

While much work continues on the individual sub-subsystems, the global commissioning of ATLAS is now gathering speed. In early June (4-18) the third milestone run (M3) was dedicated to operating the experiment as a whole. Keeping each of the incomplete sub-systems running stably over many days is no small challenge. Multiply this by the number of sub-detectors involved (see below), and add the infrastructure (computing, power and cooling), DCS and safety systems, and you might well wonder if it can work at all. But work it did! Week-1 In the first week the calorimeters and the barrel muons were triggered via the Central Trigger Processor (CTP) and read out by the central DAQ. As these detectors had been used in the previous milestone run (M2), the emphasis was on monitoring and exercising the formal shift procedures. Each detector was initialized and monitored from their dedicated sub-system desk in the ATLAS control room, and the global run was controlled from the run-control desk. Thanks to all of the pr...

The CMS central DAQ system is built using commercial hardware (PCs and networking equipment), except for two components: the Front-end Readout Link (FRL) and the Fast Merger Module (FMM). The FRL interfaces the sub-detector specific front-end electronics to the central DAQ system in a uniform way. The FRL is a compact-PCI module with an additional PCI 64bit connector to host a Network Interface Card (NIC). On the sub-detector side, the data are written to the link using a FIFO-like protocol (SLINK64). The link uses the Low Voltage Differential Signal (LVDS) technology to transfer data with a throughput of up to 400 MBytes/s. The FMM modules collect status signals from the front-end electronics of the sub-detectors, merge and monitor them and provide the resulting signals with low latency to the first level trigger electronics. In particular, the throttling signals allow the trigger to avoid buffer overflows and data corruption in the front-end electronics when the data produced in the front-end exceeds the c...

Particle identification at high rates is an important challenge for many current and future high-energy physics experiments. The upgrade of the COMPASS RICH-1 detector requires a new technique for Cherenkov photon detection at count rates of several $10^6$ per channel in the central detector region, and a read-out system allowing for trigger rates of up to 100 kHz. To cope with these requirements, the photon detectors in the central region have been replaced with the detection system described in this paper. In the peripheral regions, the existing multi-wire proportional chambers with CsI photocathode are now read out via a new system employing APV pre-amplifiers and flash ADC chips. The new detection system consists of multi-anode photomultiplier tubes (MAPMT) and fast read-out electronics based on the MAD4 discriminator and the F1-TDC chip. The RICH-1 is in operation in its upgraded version for the 2006 CERN SPS run. We present the photon detection design, constructive aspects and the first Cherenkov light ...

We have recently developed a prototypical radiophotoluminescent glass plate dosimeter (GPD) system as a device for small field dosimetry. The purpose of this study is to examine the usefulness of the GPD system for small field dosimetry. The profiles measured with the GPD were evaluated by comparing them to those from Kodak X-Omat V and GAFCROMIC XR type R film dosimeters for 2, 5, 9, and 15 mm circular collimators created by a linear accelerator-based radiosurgery system. The GPD output factors were compared with those of various detectors including an ion chamber, a p-type silicon diode detector, a glass rod dosimeter (GRD), and a diamond detector. The results measured with the GPD were also confirmed by comparing them to those from Monte Carlo simulations. The accuracy of a simulated beam is validated by the excellent agreement between Monte Carlo calculated and measured central axis depth-dose curves for 9- and 15 mm circular collimators using 4- and 10 MV photon beams. The GPD profiles show almost the same full width at half maximum as those of film dosimeters and Monte Carlo simulations at 4- and 10 MV photon beams, but a little narrower penumbrae than the film dosimeters and Monte Carlo simulations. The output factors measured with the GPD are in good agreement with those from a diode detector, a diamond detector, and the GRD with a small active volume and Monte Carlo simulations, except for a very small 2 mm circular collimator. It was found that the GPD is a very useful detector for small field dosimetry. PMID:16013713

The FIASCO multidetector is a low-threshold apparatus, optimized for the investigation of peripheral to semi-central collisions in heavy ion reactions at Fermi energies. It consists of three types of detectors. The first detector layer is a shell of 24 position-sensitive Parallel Plate Avalanche Detectors (PPADs), covering about 70% of the forward hemisphere, which measure the velocity vectors of the heavy (Z > or approx. 10) reaction products. Below and around the grazing angle, behind the most forward PPADs, there are 96 {delta}E-E silicon telescopes (with thickness of 200 and 500 {mu}m, respectively); they are mainly used to measure the energy of the projectile-like fragment and to identify its charge and, via the time-of-flight of the PPADs, also its mass. Finally, behind most of the PPADs there are 158 (or 182, depending on the configuration) scintillation detectors, mostly of the phoswich type, which cover 25-30% of the forward hemisphere; they identify both light charged particles (Z=1,2) and intermediate mass fragments (3{<=}Z < or approx. 20), measuring also their time-of-flight.

Calorimetry in large detectors at LHC poses some requirements on readout electronics which are quite different than for central tracking and muon tracking. The main distinction is, (a) in the large dynamic range of the energies to be measured; and (b) uniformity of response and accuracy of calibration over the whole detector. As in all other functions of the detector, low noise is essential. High luminosity results in pileup effects, which are present in every measurement, and in high radiation for front and forward parts of the calorimeter. Power dissipation and cooling is a concern as in any other detector component, in some respects only more so, since all the elements of the signal processing chain require more power due to the large dynamic range, speed of response, high precision and low noise required. The key requirements on the calorimetry readout electronics are briefly discussed here, with an emphasis on the dynamic range. While there are quite significant differences in the principles and technology among the crystals, tiles with fibers and liquid ionization, the signal is finally reduced to a charge measurement from a capacitive source in all three cases, and the signal processing chain becomes remarkably identical.

The Inter Cryostat Detector (ICD) used in Run I of the D0 Experiment will be inoperable in the central, high magnetic field planned for Run II. In Run I, the ICD enhanced the hermeticity and uniformity of the D0 calorimeter system, improving both missing transverse energy and jet energy resolution. The goals for the Run II ICD are the same. In this document, the physics arguments for maintaining the ICD are presented, followed by a detailed description of the planned design changes, prototype tests, construction, installation, and commissioning of the device for the Run II D0 detector. Estimates of costs and schedule can be found on //DOSERVER2/Operations/Upgrade Project/ subareas available via DZERO`s WinFrame Program Manager. This detector is not intended to provide any ``L0`` capabilities (for luminosity monitoring), or to provide any EM coverage in the intermediate region, or to provide additional coverage in the intermediate regions, unlike previous upgrades proposed in this detector region. The ICD upgrade described here maintains most of the Run I capabilities in a high magnetic field environment.

A preshower Photon Multiplicity Detector (PMD) is proposed to be implemented in the ALICE experiment to study event shapes and isospin fluctuations. The PMD, to be mounted on the magnet door at 6m from the vertex, has fine granularity and full azimuthal coverage in the pseudo-rapidity region 1.8detector is based on a cellular honeycomb proportional chamber design for both the PMD and the CPV, and has a total of about 2 x 105 cels of 1 cm2 area. The honeycomb walls form a common cathode, operated at a high negative voltage. The signal is read out from the anode wires at ground potential using gassiplex electronics. The detector employs an inert gas mixture of Ar (70%) and CO2 (30%). Beam test results for a small prototype indicate that about 80% of the central volume of the detector has almost uniform efficiency (about 95%) for MIP detection. The average number of cells fired by a MIP is close to uni...

A Time Projection Chamber (TPC) is a candidate for the central tracker of the ILC detectors. TPCs based on Micropattern Gaseous Detectors (MPGD), described in the ILC Reference Design Report, have dimensions of 2.8-4 m in diameter and 3-4.6 m in length. They are to provide 200 space points with pad readout, along a particle track with the R? spatial resolution of 100?m per row or better. The momentum resolution of ?(1/pt)?0.5×10-4(GeV/c)-1 is envisaged in the magnetic field of 3-4 T. To realize the excellent space point resolution of 100?m, a TPC with MPGD readout instead of the Multiwire Proportional Chamber (MWPC) readout is needed [1]. The MPGD under consideration are Gas Electron Multiplier (GEM) and Micromesh Gas detector (Micromegas). Both detectors are operated either with regular analog pad readout or with the digital TimePix readout. A Large Prototype (LP) of a TPC has been constructed, which has a diameter of about 750 mm and a length of about 600 mm and allows to measure tracks with up to 125 space points with pad readout. This prototype is fitting into a superconducting magnet, installed in a DESY test beam area and is exposed to 6 GeV electrons. A description of the setup as well as first beam results with the various readout options of the LP will be given.

Event Builder One of the key design features of CMS is the large Central Data Acquisition System capable of bringing over 100 GB of data to the surface and building 100,000 events every second. This very large DAQ system is ex¬pected to give CMS a competitive advantage since we can have a very flexible High Level Trigger entirely run¬ning on standard computer processors. The first stage of what will be the largest DAQ system in the world is now being commissioned at Point 5. While the detector has been read out until now by a small system called the mini-DAQ, the large central DAQ Event Builder has been put together and debugged over the last 4 months. During the month of September, the full system from FED (front end connection to the detector readout) to Filter Unit is being commissioned and we hope to use the central DAQ Event Builder for the Global Run at the end of September. The first batch of 400 computers arrived around in mid-April. These computers became Readout Units (RUs), wit...

This report documents the activities within the CBM project in 2007. Significant progress has been made in the optimization of the simulation software, the layout and development of detectors, the design of front-end electronics, and the concepts for data acquisition. The simulation and analysis routines have been completely integrated into the software framework (FAIRoot and CBMroot), and can be used now easily by users outside GSI. A breakthrough has been achieved in the development of fast algorithms for track and vertex reconstruction which have been improved in speed by a factor of 10{sup 5}. These fast routines permit to perform high-statistics simulations for detailed detector layout optimization. Full event reconstruction based on realistic detector properties and particle multiplicities as given by microscopic transport models are routinely used in the feasibility studies. A version of the Silicon Tracking System is now implemented in the simulation software comprising 8 detector layers based on microstrip technology only, including the readout cables, and the mechanical detector structure. The studies of open charm detection have been extended to D{sub s}{sup +} and {lambda}{sub c}, taking into account a realistic layout of the Silicon Pixel Microvertex detector. The identification of electrons has been optimized by improved ring recognition algorithms and transition radiation simulations. The Ring Imaging Cherenkov (RICH) detector has been redesigned, resulting in a reduction by a factor of two in mirror size and number of readout channels without reducing the pion rejection capability. The muon detection system has been optimized with respect to the number of detector layers. The muon simulations take into account detector inefficiencies and a segmentation of the muon chambers into pads according to a nominal occupancy of 5% for central Au+Au collisions. Studies for a dimuon trigger show promising results. Radiation dose simulations using the FLUKA transport code have been started. A new generation of pixel sensors for the Microvertex detector (MVD) with fast read-out architecture has been tested with pion beams at CERN. The tolerance of the sensors to non-ionizing radiation has been improved, and the construction of a MVD demonstrator has been started. The first double-side microstrip sensors have been built and will be tested. Prototype MWPCs for the measurement of transition radiation have been tested and optimized for high rate capability. Prototype staw-tube tracker modules have been built and tested. The n-XYTER readout ASIC was characterized in various test benches and is now ready for deployment in detector and beam tests in 2008. The design work on the CBM-XYTER, a radiation-hard second-generation readout ASIC for Silicon and fast gas detectors, has started in 2007. The FEE development for the RPC-TOF system saw two major milestones in 2007: the preamplifier-discriminator chip PADI was successfully tested, and the preparatory studies of several time-to-digital converter buildings blocks were concluded with the design choices for the first full system chip to be developed in 2008. Within the development of a future data acquisition system, the scalability of high-throughput event building was demonstrated on a 110 node cluster. A very important milestone will be the proton beam test of Silicon microstrip and gas detectors read out by n-XYTER ASICs at GSI end of September 2008. (orig.)

A commercial 2D array seven29 detector has been characterized and its performance has been evaluated. 2D array ionization chamber equipped with 729 ionization chambers uniformly arranged in a 27 x 27 matrix with an active area of 27 x 27 cm^2 was used for the study. An octagon-shaped phantom (Octavius Phantom) with a central cavity is used to insert the 2D ion chamber array. All measurements were done with a linear accelerator. The detector dose linearity, reproducibility, output factors, dose rate, source to surface distance (SSD), and directional dependency has been studied. The performance of the 2D array, when measuring clinical dose maps, was also investigated. For pretreatment quality assurance, 10 different RapidArc plans conforming to the clinical standards were selected. The 2D ar...

The air fluorescence detectors (FDs) of the Pierre Auger Observatory are vital for the determination of the air shower energy scale. To compensate for variations in atmospheric conditions that affect the energy measurement, the Observatory operates an array of monitoring instruments to record hourly atmospheric conditions across the detector site, an area exceeding 3,000 square km. This paper presents results from four instruments used to characterize the aerosol component of the atmosphere: the Central Laser Facility (CLF), which provides the FDs with calibrated laser shots; the scanning backscatter lidars, which operate at three FD sites; the Aerosol Phase Function monitors (APFs), which measure the aerosol scattering cross section at two FD locations; and the Horizontal Attenuation Monitor (HAM), which measures the wavelength dependence of aerosol attenuation.

The Tile Calorimeter (TileCal) is the hadronic calorimeter covering the most central region of the ATLAS experiment at LHC. I consists of about 1000 channels. The main upgrade will occur for the High Luminosity LHC phase (phase 2) scheduled around 2022. The upgrade aims at replacing the majority of the on- and off-detector electronics so that all calorimeter signals are directly digitized and sent to the off-detector electronics in the counting room. This will be done with minimum latency and maximum robustness. It will provide maximum information to the first level of the calorimeter trigger to improve the trigger efficiency as required to cope with the increased luminosity. Three options are presently being investigated for the front-end electronic upgrade. The first option is an improved version of the present system built using discrete components. The second alternative is based on the development of a dedicated ASIC, which will provide most of the functionality including the digitization. The third alte...

laurent & calin 2003 Athens: the Titan ATLAS, after weighing the Earth many years ago, continues its search on the mass problem and on the Higgs in particular ? and gives results on the beam tests and simulations. Inner detector layout and flavor tagging Much effort has been dedicated to improve b-tagging efficiency, developing new sophisticated methods and more precise tuning of the good old and simple algorythms. But, we have to wait for eight months of datataking to reach an efficient b-tagging. The loss of performance, mainly produced by the increase of the b-layer radius and material changes, was compensated by the software improvements and verified on DC1 data.  Undoubtedly, the confirmation that the required performance can be achieved is coming from the test beams studies. The detector alignment has well advanced software and the tools are waiting to be used efficiently. Even if there are many things to be understood in lead-lead central collisions, encouraging b-tagging resul...

We present Monte Carlo preliminary results about the feasibility to detect the ? c family in p-p collisions at 14 TeV in the ALICE Central Barrel at CERN LHC. The ? c1 and ? c2 were forced to decay in the radiative channel J/ ?+ ?? e + e -+ ? and were merged with a proton-proton non-biased collision. After Monte Carlo transport and simulation of the detector response, the e +, e - and converted ? were reconstructed and identified in the ALICE ITS, TPC and TRD detectors. Separate signals corresponding to ? from ? c1 and from ? c2 were observed. The position and relative weight of the fit to gaussians agreed with the input values within the statistical limits.

The balloon-borne cosmic-ray experiment CREAM-I (Cosmic-Ray Energetics And Mass) completed a successful 42-day flight during the 2004-2005 NASA/NSF/NSBF Antarctic expedition. CREAM-I combines an imaging calorimeter with charge detectors and a precision transition radiation detector (TRD). The TRD component of CREAM-I is targeted at measuring the energy of cosmic-ray particles with charges greater than Z~3. A central science goal of this effort is the determination of the ratio of secondary to primary nuclei at high energy. This measurement is crucial for the reconstruction of the propagation history of cosmic rays and consequently, for the determination of their source spectra. Initial results from the TRD portion of the science stack will be presented.

We study the bunch field diffusion and energy dissipation in the beam pipe of the Super-B detector, which consists of two coaxial Be thin pipes (half a millimeter). Cooling water will run between these two pipes. Gold and nickel will be sputtered (several microns) onto the beryllium pipe at different sides. The Maxwell equations for the beam fields in these thin layers are solved numerically for the case of infinite pipes. We also calculate the amplitude of the electromagnetic fields outside the beam pipe, which may be noticeable as the beam current can reach 4 A in each beam. Results of simulations are used for the design of this central part of the Super-B detector.

The ALICE detector at the LHC (A Large Ion Collider Experiment) will carry out comprehensive measurements of high energy nucleus-nucleus collisions, in order to study QCD matter under extreme conditions and the phase transtion between conï¬�ned matter and the Quark-Gluon Plasma (QGP). This report presents our current state of understanding of the Physics Performance of the large acceptance Electromagnetic Calorimeter (EMCal) in the ALICE central detector. The EMCal enhances ALICEâ??s capabilities for jet measurements. The EMCal enables triggering and full reconstruction of high energy jets in ALICE, and augments existing ALICE capabilities to measure high momentum photons and electrons. Combined with ALICEâ??s excellent capabilities to track and identify particles from very low pT to high pT , the EMCal enables a comprehensive study of jet interactions in the medium produced in heavy ion collisions at the LHC.

After proposing a new method of deriving the atmospheric time constant from the speed of focus variations (Kellerer & Tokovinin 2007), we now implement it with the new instrument, FADE. FADE uses a 36-cm Celestron telescope that is modified to transform stellar point images into a ring by increasing the central obstruction and combining defocus with spherical aberration. Sequences of images recorded with a fast CCD detector are processed to determine the defocus and its variations in time from the ring radii. The temporal structure function of the defocus is fitted with a model to derive the atmospheric seeing and time constant. We investigated by numerical simulation the data reduction algorithm and instrumental biases. Bias caused by instrumental effects, such as optical aberrations, detector noise, acquisition frequency, etc., is quantified. The ring image must be well-focused, i.e. must have a sufficiently sharp radial profile, otherwise, scintillation seriously affects the results. An acquisition fre...

We discuss a method to obtain the true event-by-event net-charge multiplicity distributions from a corresponding measured distribution which is subjected to detector effects such as finite particle counting efficiency. The approach is based on the Bayes method for unfolding of distributions. We are able to faithfully unfold back the measured distributions to match with their corresponding true distributions obtained for a widely varying underlying particle production mechanism, beam energy and collision centrality. Particularly the mean, variance, skewness, kurtosis, their products and ratios of net-charge distributions from the event generators are shown to be successfully unfolded from the measured distributions constructed to mimic a real experimental distribution. We demonstrate the necessity to account for detector effects before associating the higher moments of net-charge distributions with physical quantities or phenomena. The advantage of this approach being that one need not construct new observable...

Scintillating fibers are capable of charged particle tracking with high position resolution, as demonstrated by the central fiber tracker of the D0 experiment. The charged particles will deposit less energy in the polystyrene scintillating fibers as opposed to a typical silicon tracker of the same thickness, while SiPM's are highly efficient at detecting photons created by the passage of the charged particle through the fibers. The current prototype of the Proton Computed Tomography (pCT) tracker uses groups of three 0.5 mm green polystyrene based scintillating fibers connected to a single SiPM, while first generation prototype tracker used Silicon strip detectors. The results of R&D for the Scintillating Fiber Tracker (SFT) as part of the pCT detector are outlined, and the premise for the selection of SiPM is discussed.

This progress report describes U of Oklahoma participation in a number of detector development efforts. The first is a beam solid state device which was performance tested in runs during June and July, 1984. This was a partially instrumented test of an array of gridded solid state detectors. A beam drift chamber was also performance tested. This consist of 18 planes of 2 cells each. Each cell has drift distance of 18 mm on each side of the sense wire. Preliminary tests were also performed on a time-of-flight counter system. The system was not totally instrumented but resolution was able to be measured for its central section at least. Tests showed a number of drifts which can be monitored and corrected. Test results were also collected for the hadron calorimeter for experiment E-653 at Fermilab.

The MUNU detector was designed to study neutrino-electron elastic scattering at low energy. The central component is a Time Projection Chamber filled with CF4 gas, surrounded by an anti-Compton detector. The experiment was carried out at the Bugey (France) nuclear reactor. In this paper we present the final analysis of the data recorded at 3 bar and 1 bar pressure. Both the energy and the scattering angle of the recoil electron are measured. From the 3 bar data a new upper limit on the neutrino magnetic moment was derived. At 1 bar electron tracks down to 150 keV were reconstructed, demonstrating the potentiality of the experimental technique for future applications in low energy neutrino physics.

The alignment system for the muon spectrometer of the CMS detector comprises three independent subsystems of optical and analog position sensors. It aligns muon chambers with respect to each other and to the central silicon tracker. System commissioning at full magnetic field began in 2008 during an extended cosmic ray run. The system succeeded in tracking muon detector movements of up to 18 mm and rotations of several milliradians under magnetic forces. Depending on coordinate and subsystem, the system achieved chamber alignment precisions of 140-350 {mu}m and 30-200 {mu}rad, close to the precision requirements of the experiment. Systematic errors on absolute positions are estimated to be 340-590 {mu}m based on comparisons with independent photogrammetry measurements.

The ZEUS Central Tracking Detector utilizes a time difference measurement to provide a fast determination of the z-coordinate of each hit. The z-by-timing measurement is achieved by using a Time-to-Amplitude Converter which has an intrinsic timing resolution of 36 ps, has pipelined readout, and has a multihit capability of 48 ns. In order to maintain the required sub-nanosecond timing accuracy, the technique incorporates an automated self-calibration system. The readout of the z-by-timing data utilizes a fully customized timing control system which runs synchronously with the HERA beam-crossing clock, and a data acquisition system implemented on a network of Transputers. Three dimensional space-points provided by the z-by-timing system are used as input to all three levels of the ZEUS trigger and for offline track reconstruction. The average z-resolution is determined to be 4.4 cm for multi-track events from positron-proton collisions in the ZEUS detector.

This procedure is intended for the Area Radiation Monitoring System, ARMS, that is replacing the existing Programmable Input-Output Processing System, PIOPS, radiation monitoring system in the 105KE basin. The new system will be referred to as the 105KE ARMS, 105KE Area Radiation Monitoring System. This ATP will ensure calibration integrity of the 105KE radiation detector loops. Also, this ATP will test and document the display, printing, alarm output, alarm acknowledgement, upscale check, and security functions. This ATP test is to be performed after completion of the 105KE ARMS installation. The alarm outputs of the 105KE ARMS will be connected to the basin detector alarms, basin annunciator system, and security Alarm Monitoring System, AMS, located in the 200 area Central Alarm Station (CAS).

These proceedings report of two measurements performed with the ATLAS detector. These measurements use the notion of 'rapidity gaps', although the definition of gap and the probed physics are quite different. The paper [1] presents the rapidity gap cross sections measured with the ATLAS detector using early 2010 pp collisions data. Gap translates the absence of particle produced in a rapidity region. Diffractive events are recorded using the Minimum Bias Trigger Scintillators mounted in front of the end-cap calorimeters. The paper [2] presents the measurement of dijet production with a jet veto on additional central jet activity in pp collisions recorded by ATLAS in 2010. Rapidity gaps are defined by the absence of jet in the rapidity interval bounded by the dijet system, of transverse momentum above 20 GeV. There is therefore some QCD activity in these rapidity gaps. Dijet events are collected using calorimeters jets trigger.

We confirmed the defect detection performances of the remote field eddy current testing (RFECT) in order to inspect the helical-coil-type double wall tube steam generator (DWTSG) with the wire mesh layer for the new small fast reactor 4S (Super-Safe, Small and Simple). As the high sensitivity techniques, we tried to increase the direct magnetic field intensity in the vicinity of the inner wall of the tube and decrease the direct magnetic field around the central axis of the tube using the exciter coil with the flux guide made of the iron-nickel alloy. We adopted the horizontal type multiple detector coils with the flux guides arrayed circumferentially to enhance the sensitivity of the radial component. According to the experimental results, the output voltage of the detector coil in the re...

The four main LHC experiments and the accelerator department have agreed to use a unique commercial SCADA system, PVSS II from ETM (Austria) for detector and accelerator slow control purposes, in order to ease connection and exchange of data among all collaborators and to minimise central support effort for commonly used software and LHC specific libraries provided by the CERN IT department. Knowing this, the PVSS Data Viewer (PDV) had originally been developed to access environment and control data of the Pixel detector of the ATLAS experiment, with an effort to be sufficiently generic to provide access to data of other subdetectors and even data of other experiments, or PVSS systems in general. Other important keys for the design were independence from any existing PVSS installation and universality regarding computer operating systems or user environments. The universality condition has led to the choice of Java as programming language, which also allows to start applications with WebStart technology right...

An analytical device for rapid, non-invasive nuclear magnetic resonance (NMR) spectroscopy of multiple samples using a single spectrometer is provided. A modified toroid cavity/coil detector (TCD), and methods for conducting the simultaneous acquisition of NMR data for multiple samples including a protocol for testing NMR multi-detectors are provided. One embodiment includes a plurality of LC resonant circuits including spatially separated toroid coil inductors, each toroid coil inductor enveloping its corresponding sample volume, and tuned to resonate at a predefined frequency using a variable capacitor. The toroid coil is formed into a loop, where both ends of the toroid coil are brought into coincidence. Another embodiment includes multiple micro Helmholtz coils arranged on a circular perimeter concentric with a central conductor of the toroid cavity.

The International Large Detector (ILD) is a concept for a detector at the International Linear Collider, ILC. The ILC will collide electrons and positrons at energies of initially 500 GeV, upgradeable to 1 TeV. The ILC has an ambitious physics program, which will extend and complement that of the Large Hadron Collider (LHC). The ILC physics case has been well documented, most recently in the ILC Reference Design Report, RDR. A hallmark of physics at the ILC is precision. The clean initial state and the comparatively benign environment of a lepton collider are ideally suited to high precision measurements. To take full advantage of the physics potential of ILC places great demands on the detector performance. The design of ILD, which is based on the GLD and the LDC detector concepts, is driven by these requirements. Excellent calorimetry and tracking are combined to obtain the best possible overall event reconstruction, including the capability to reconstruct individual particles within jets for particle flow calorimetry. This requires excellent spatial resolution for all detector systems. A highly granular calorimeter system is combined with a central tracker which stresses redundancy and efficiency. In addition, efficient reconstruction of secondary vertices and excellent momentum resolution for charged particles are essential for an ILC detector. The interaction region of the ILC is designed to host two detectors, which can be moved into the beam position with a 'push-pull' scheme. The mechanical design of ILD and the overall integration of subdetectors takes these operational conditions into account. The main features of ILD are outlined below. The central component of the ILD tracker is a Time Projection Chamber (TPC) which provides up to 224 precise measurements along the track of a charged particle. This is supplemented by a system of Silicon (Si) based tracking detectors, which provide additional measurement points inside and outside of the TPC, and extend the angular coverage down to very small angles. A Si-pixel based vertex detector (VTX) enables long lived particles such as b- and c-hadrons to be reconstructed. This combination of tracking devices, which has a large degree of redundancy, results in high track reconstruction efficiencies, and unprecedented momentum resolution and vertex reconstruction capabilities. One of the most direct measures of detector performance at the ILC is the jet-energy resolution. Precise di-jet mass reconstruction and separation of hadronically decaying W and Z bosons are essential for many physics channels. The ultimate jet energy resolution is achieved when every particle in the event, charged and neutral, is measured with the best possible precision. Within the paradigm of particle flow calorimetry, this goal is achieved by reconstructing charged particles in the tracker, photons in the electromagnetic calorimeter (ECAL), and neutral hadrons in the ECAL and hadronic calorimeter (HCAL). The ultimate performance is reached for perfect separation of charged-particle clusters from neutral particle clusters in the calorimeters. Thus, a highly granular calorimeter outside the tracker is the second key component of ILD. Sampling calorimeters with dense absorber material and fine grained readout are used. A tungsten absorber based electromagnetic calorimeter (ECAL) covers the first interaction length, followed by a somewhat coarser steel based sampling hadronic calorimeter (HCAL). Several ECAL and HCAL readout technologies are being pursued.

Axial injection into a cyclotron through its iron yoke, a spiral inflector, and the central region electrodes couples the transverse coordinates of motion together, as well as with the longitudinal coordinates. The phase slits in the K1200 cyclotron use the r - {phi} correlations inherent in acceleration of ions in a cyclotron. Computer simulations of injection into and acceleration within the K1200 cyclotron encompassing the four transverse dimensions together with time were used to determine beam matching requirements for injection and phase selection in the K1200 cyclotron. The simulations were compared with measurements using an external timing detector.

The NA49 detector system at the CERN SPS studies a variety of nuclear reactions ranging from p+p via p+A with controlled impact parameter to Pb+Pb collisions with different centralities. Tracking (by time projection chambers) and particle identification (by dE/dx therein) cover the full projectile hemisphere for produced particles. This permits a comprehensive study of antiprotons - notwithstanding their small abundance relative to other particle species-with the aim to scrutinize the evolution of the production characteristics from the most elementary to the most complex and energy-dense hadronic interactions. (5 refs).

The preliminary results on the search for hard diffraction in pp collisions with the D0 detector at Fermilab are presented. The presence of forward rapidity gaps is observed in events with high transverse momentum jet production at the center of mass energies 1800 and 630 GeV. The fraction of events with rapidity gaps is significantly higher than that expected due to multiplicity fluctuations and is consistent with predictions for hard single diffractive jet production. A class of events containing central dijets and two forward rapidity gaps is observed at {radical}s = 1800 GeV consistent with a hard double pomeron exchange event topology.

This letter newly proposes a new multi-user detection scheme for multiple users using co-channel heterogeneous radio signals in ubiquitous antenna system. The ubiquitous antenna system is composed of multiple radio base stations (RBSs), the central control station (CCS) which performs the multi-user detection, and radio-on-fiber (RoF) link which connects the RBSs to the CCS. Computer simulation results show that the multi-user detector exploiting the minimum mean square error (MMSE)-based combiner and the serial interference canceller (SIC) in combination can achieve the coexistence of coded orthogonal frequency division multiplexing (COFDM) and direct sequence spread spectrum (DSSS) signals.   

We study the peripheral ion collisions at LHC energies where a nucleus is excited to a discrete state and then emits gamma -rays. Large nuclear Lorenz factors allow the observation of high-energy photons up to a few tens GeV and in the angular region of a few hundred microradians from the beam direction. These photons can be used to tagg events with particle production in the central rapidity region in ultraperipheral collisions. To detect these photons it is necessary to have an electromagnetic detector in front of the zero- degree calorimeter in LHC experiments.

Light-particle emission from Au+Au collisions has been studied in the bombarding-energy range 100-250A.MeV, using {Delta}E-E{sub R} telescopes in coincidence with the FOPI detector in its phase I configuration. Center-of-mass energy spectra have been measured for Z=1, 2 isotopes emitted in central collisions at CM polar angles between 60 {sup circle} and 90 {sup circle}. Evidence for a collective expansion is reported, on the basis of the mean kinetic energies of hydrogen isotopes. Comparison is presented with statistical calculations (WIX code). For CM kinetic energy spectra, fair agreement is found between data and a recently developed transport model. ((orig.)).

The inclusive production cross sections of the charmed mesons D^0, D^+, D_s^+ and D^{*+} have been measured in interactions of 920 GeV protons on C, Ti, and W targets with the HERA-B detector at the HERA storage ring. Differential cross sections as a function of transverse momentum and Feynman's x variable are given for the central rapidity region and for transverse momenta up to $\\pT=3.5$ GeV/$c$. The atomic mass number dependence and the leading to non-leading particle production asymmetries are presented as well.

A tri-functional cannula combines the functions of tissue Plasminogen Activator (tPA) solution delivery, illumination and venous pressure measurement. The cannula utilizes a tapered hollow-core optical fiber having an inlet for tPA solution, an attached fiber optic splitter configured to receive illumination light from an optical source such and a LED. A window in the cannula transmits the light to and from a central retinal vein. The return light is coupled to an optical detector to measure the pressure within the vein and determine whether an occlusion has been removed.

Their long range in matter renders high-energy atmospheric muons a unique probe for geophysical explorations, permitting the cartography of density distributions which can reveal spatial and possibly also temporal variations in extended geological structures. A Collaboration between volcanologists and (astro-)particle physicists, TOMUVOL, was formed in 2009 to study tomographic muon imaging of volcanos with high-resolution tracking detectors. Here we discuss preparatory work towards muon tomography as well as the first flux measurements taken at the Puy de Dôme, an inactive lava dome volcano in the Massif Central.

The Level-2 Silicon Track Trigger preprocessor (L2 STT) of the D0 detector in Run II is described. It performs a precise reconstruction of charged particle tracks in the Central Fiber Tracker (CFT) and the Silicon Microstrip Tracker (SMT). Events with displaced tracks originating from the decay of long living particles such as B hadrons are triggered on. The presence of b quarks contained in such hadrons is relevant for B physics and crucial as signature of top quark and Higgs boson decays.

Jets have been studied by the CDF Collaboration [1] as a means of searching for new particles and interactions, testing a variety of perturbative QCD predictions, and providing input for the global parton distribution function (PDF) fits. Unless otherwise indicated below, the jets were reconstructed using a cone algorithm [2] with cone radius R = 0.7 from data taken at the Fermilab Tevatron collider in Run 2, 2001-2003, with {radical}s = 1.96 TeV. Central jets, in the pseudorapidity range relative to fixed detector coordinates 0.1 < |{eta}| < 0.7, are used.

Using the facilities of the KASCADE Central Detector EAS muon arrival time distributions, observed with reference to the arrival time of the first locally registered muon, and their correlations with other EAS observables have been investigated at different distances R{sub {mu}} from the shower axis. Invoking detailed Monte Carlo simulations non-parametric multivariate even-by-event analyses have been performed for an estimate of the primary mass composition. The consistency of the Monte Carlo simulations is studied by comparing the primary mass composition results inferred from observations at different R{sub {mu}} and different muon multiplicity thresholds n{sub th}.

The experience of the Collider Detector at Fermilab (CDF) with aging in the large axial drift chamber responsible for tracking in the central region is presented. Premature aging in the Run 1 chamber was observed after only 0.02 C/cm. After cleaning much of the gas system and making modifications to reduce aerosols from the alcohol bubbler, the observed aging rate fell dramatically in test chambers. Considerable effort has been made to better understand the factors that affect aging since the replacement chamber for Run 2 will accumulate about 1.0 C/cm. Current test chambers using the full CDF gas system show aging rates of less than 5%/C/cm.

Correlations in the azimuthal angle between the two largest transverse momentum jets have been measured using the D0 detector in pp-bar collisions at a center-of-mass energy $\\sqrt{s}$=1.96 TeV. The analysis is based on an inclusive dijet event sample in the central rapidity region corresponding to an integrated luminosity of 150 pb-1. Azimuthal correlations are stronger at larger transverse momenta. These are well-described in perturbative QCD at next-to-leading order in the strong coupling constant, except at large azimuthal differences where soft effects are significant.

Forward-backward correlations of charged-particle multiplicities in symmetric bins in pseudorapidity are studied in order to gain insight into the underlying correlation structure of particle production in Au+Au collisions. The PHOBOS detector is used to measure integrated multiplicities in bins centered at eta, defined within |eta|<3, and covering intervals Delta-eta. The variance sigma^2_C of a suitably defined forward-backward asymmetry variable C is calculated as a function of eta, Delta-eta, and centrality. It is found to be sensitive to short range correlations, and the concept of "clustering'' is used to interpret comparisons to phenomenological models.

The study of flow can provide information on the initial state dynamics and the degree of equilibration attained in heavy ion collisions. This contribution presents results for both elliptic and directed flow as determined from data recorded by the PHOBOS experiment in Au+Au runs at RHIC at sqrt(sNN) = 19.6, 130 and 200 GeV. The PHOBOS detector provides a unique coverage in pseudorapidity for measuring flow at RHIC. The systematic dependence of flow on pseudorapidity, transverse momentum, centrality and energy is discussed.

We present a search for fJ(2220) production in radiative J/???fJ(2220) decays using 460fb-1 of data collected with the BABAR detector at the SLAC PEP-II e+e- collider. The fJ(2220) is searched for in the decays to K+K- and KS0KS0. No evidence of this resonance is observed, and 90% confidence level upper limits on the product of the branching fractions for J/???fJ(2220) and fJ(2220)?K+K-(KS0KS0) as a function of spin and helicity are set at the level of 10-5, below the central values reported by the Mark III experiment.

During RHIC 2010 run, STAR has collected a large amount of minimum-bias, central and high $p_{T}$ trigger data in Au+Au collisions at $\\sqrt{s_{NN}} = 39$, 62.4 and 200 GeV with detector configuration for minimum photonic conversion background. In this article we report on a new high precision measurement of non-photonic electron mid-rapidity invariant yield, improved nuclear modification factor and $v_{2}$ in Au+Au collisions at $\\sqrt{s_{NN}} = 200$ GeV. We also present measurements of mid-rapidity invariant yield at $\\sqrt{s_{NN}} = 62.4$ and $v_{2}$ at $\\sqrt{s_{NN}} = 39$ and 62.4 GeV.

Critical to the detection of X-rays by CCDs, is the detailed process of charge diffusion and drift within the device. We reexamine the prescriptions currently used in the modeling of X-ray CCD detectors to provide analytic expressions for the charge distribution over the CCD pixels which are suitable for use in numerical simulations of CCD response. Our treatment results in models which predict charge distributions which are more centrally peaked and have flatter wings than the Gaussian shapes predicted by previous work and adopted in current CCD modeling codes.

The measurements carried out on reactor dosimetry are applied mainly to the study on the effects of the radiation in 108 materials of the reactor; little is on the environmental dosimetry outside of the primary container of BWR reactors. In this work the application of a neutron spectrometer formed by plastic detectors of nuclear traces manufactured in the ININ, for the environmental monitoring in penetrations around the primary container of the unit I of the Laguna Verde central is presented. The neutron monitoring carries out with purposes of radiological protection, during the operational tests of the reactor. (Author)

The distribution of the transverse energy in jets has been measured in p{anti p} collisions at {radical}s = 1.8 TeV using the D0 detector at Fermilab. This measurement of the jet shape is made as a function of jet transverse energy in both the central and forward rapidity regions. Jets are observed to narrow both with increasing transverse energy and with increasing rapidity. Next-to-leading order partonic QCD calculations are compared to the data. Although the calculations qualitatively describe the data, they are shown to be very dependent on renormalization scale, parton clustering algorithm and jet direction definition and fail to consistently describe the data in all regions.

The central tracking device of the DELPHI Experiment at LEP is a Time Projection Chamber (TPC) with an active volume of 2 x 1.34m in length and 2.22m in diameter. Since spring 1988 the TPC has undergone extensive tests in a cosmic ray set-up. It will be installed in the LEP tunnel by early 1989. This report covers the construction, the read-out electronics and the contribution of the TPC to the DELPHI trigger. Emphasis is given to novelties which are not used in similar detectors.

The spectra of lepton pairs from correlated open charm and bottom decays in ultrarelativistic heavy-ion collisions are calculated. Our approach includes energy loss effects of the fast heavy quarks in deconfined matter which are determined by temperature and density of the expanding parton medium. We find a strong suppression of the initial transverse momentum spectrum of heavy quarks due to the energy loss at LHC conditions. Within the central rapidity covered by the ALICE detector system, the dominant contribution from bottom decays to the high invariant mass dielectron spectrum is predicted. (orig.)

This report describes the activities of the Heavy Ion Physics Group at the University of California, Riverside from October 1, 1990 to September 30, 1991. During this period, our program focuses on particle production at AGS energies, and correlation studies at the Bevalac in nucleus central collisions. We participated in the preparation of letters of intent for two RHIC experiments -- the OASIS proposal and the Di-Muon proposal -- and worked on two RHIC R&D efforts -- a silicon strip detector project and a muon-identifier project. A small fraction of time was also devoted to physics programs outside the realm of heavy ion reactions by several individuals.

The Milky Way is the only galaxy for which we can resolve individual stars at all evolutionary phases, from the Galactic center to the outskirt. The last decade, thanks to the advent of near IR detectors and 8 meter class telescopes, has seen a great progress in the understanding of the Milky Way central region: the bulge. Here we review the most recent results regarding the bulge structure, age, kinematics and chemical composition. These results have profound implications for the formation and evolution of the Milky Way and of galaxies in general. This paper provides a summary on our current understanding of the Milky Way bulge, intended mainly for workers on other fields.

Elliptic flow is an interesting probe of the dynamical evolution of the dense system formed in the ultrarelativistic heavy ion collisions at the Relativistic Heavy Ion Collider (RHIC). The elliptic flow dependences on transverse momentum, centrality, and pseudorapidity were measured using data collected by the PHOBOS detector, which offers a unique opportunity to study the azimuthal anisotropies of charged particles over a wide range of pseudorapidity. These measurements are presented, together with an overview of the analysis methods and a discussion of the results.

Detecting, quantifying and visualizing biochemical mechanism in a living system without perturbing function is the goal of the instrument and algorithms designed in this thesis. Biochemical mechanisms of cells have long been known to be dependent on the signals they receive from their environment. Studying biological processes of cells in-vitro can vastly distort their function, since you are removing them from their natural chemical signaling environment. Mice have become the biological system of choice for various areas of biomedical research due to their genetic and physiological similarities with humans, the relatively low cost of their care, and their quick breeding cycle. Drug development and efficacy assessment along with disease detection, management, and mechanism research all have benefited from the use of small animal models of human disease. A high resolution, high sensitivity, three-dimensional (3D) positioning positron emission tomography (PET) detector system was designed through device characterization and Monte Carlo simulation. Position-sensitive avalanche photodiodes (PSAPDs) were characterized in various packaging configurations; coupled to various configurations of lutetium oxyorthosilicate (LSO) scintillation crystals. Forty novelly packaged final design devices were constructed and characterized, each providing characteristics superior to commercially available scintillation detectors used in small animal imaging systems: ˜1mm crystal identification, 14-15% of 511 keV energy resolution, and averaging 1.9 to 5.6 ns coincidence time resolution. A closed-cornered box-shaped detector configuration was found to provide optimal photon sensitivity (˜10.5% in the central plane) using dual LSO-PSAPD scintillation detector modules and Monte Carlo simulation. Standard figures of merit were used to determine optimal system acquisition parameters. A realistic model for constituent devices was developed for understanding the signals reported by the detector system and to create event construction and utilization algorithms. To increase quantitative accuracy in the reconstructed images acquired by the system, a component-based normalization algorithm was developed.

By using the ATLAS detector, observations have been made of a centrality-dependent dijet asymmetry in the collisions of lead ions at the Large Hadron Collider. In a sample of lead-lead events with a per-nucleon center of mass energy of 2.76 TeV, selected with a minimum bias trigger, jets are reconstructed in fine-grained, longitudinally segmented electromagnetic and hadronic calorimeters. The transverse energies of dijets in opposite hemispheres are observed to become systematically more unbalanced with increasing event centrality leading to a large number of events which contain highly asymmetric dijets. This is the first observation of an enhancement of events with such large dijet asymmetries, not observed in proton-proton collisions, which may point to an interpretation in terms of strong jet energy loss in a hot, dense medium. PMID:21231581

First part of this paper (Tesar, 2011) described experimental investigations, combined with numerical flowfield computations, of a pipe flow in which a parallel wall-jet is blown along the inner surface of the pipe. The aim is to separate the main central flow and prevent its contact with the pipe wall. Although originally motivated by the problem of preventing transport of radioactivity to a radiation detector and its activation, the investigations used heat/mass transport analogy so that the actual subject of investigation was transport of heat from warm central air flow across a cool wall-jet flow into the (also cool) wall of the flow containing pipe. This heat transfer is itself also a problem which may be of interest in applications. In the previous part, apart from the description of...

A multiple cell radiation detector includes a central cell having a first cylindrical wall providing a stopping power less than an upper threshold; an anode wire suspended along a cylindrical axis of the central cell; a second cell having a second cylindrical wall providing a stopping power greater than a lower threshold, the second cylindrical wall being mounted coaxially outside of the first cylindrical wall; a first end cap forming a gas-tight seal at first ends of the first and second cylindrical walls; a second end cap forming a gas-tight seal at second ends of the first and second cylindrical walls; and a first group of anode wires suspended between the first and second cylindrical walls.