A Multi-TeV Linear Collider Based on CLIC Technology : CLIC Conceptual Design Report

Energy Technology Data Exchange (ETDEWEB)

Aicheler, M [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Burrows, P. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Draper, M. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Garvey, T. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Lebrun, P. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Peach, K. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Phinney, N. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Schmickler, H. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Schulte, D. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Toge, N. [European Organization for Nuclear Research (CERN), Geneva (Switzerland)

2014-02-13

This report describes the accelerator studies for a future multi-TeV e⁺e^- collider based on the Compact Linear Collider (CLIC) technology. The CLIC concept as described in the report is based on high gradient normal-conducting accelerating structures where the RF power for the acceleration of the colliding beams is extracted from a high-current Drive Beam that runs parallel with the main linac. The focus of CLIC R&D over the last years has been on addressing a set of key feasibility issues that are essential for proving the fundamental validity of the CLIC concept. The status of these feasibility studies are described and summarized. The report also includes a technical description of the accelerator components and R&D to develop the most important parts and methods, as well as a description of the civil engineering and technical services associated with the installation. Several larger system tests have been performed to validate the two-beam scheme, and of particular importance are the results from the CLIC test facility at CERN (CTF3). Both the machine and detector/physics studies for CLIC have primarily focused on the 3 TeV implementation of CLIC as a benchmark for the CLIC feasibility. This report also includes specific studies for an initial 500 GeV machine, and some discussion of possible intermediate energy stages. The performance and operation issues related to operation at reduced energy compared to the nominal, and considerations of a staged construction program are included in the final part of the report. The CLIC accelerator study is organized as an international collaboration with 43 partners in 22 countries. An associated report describes the physics potential and experiments at CLIC and a shorter report in preparation will focus on the CLIC implementation strategy, together with a plan for the CLIC R&D studies 2012–2016. Critical and important implementation issues such as cost, power and schedule will be addressed there.

Physics and Detectors at CLIC

CERN Multimedia

CERN. Geneva

2012-01-01

CLIC represents an attractive option for the future particle physics programme at the energy frontier. CLIC is a proposed electron-positron linear collider, based on a novel two beam accelerating structure, with the capability of operating at centre-of-mass energies of up to 3 TeV. The Physics and Detector volume of the CLIC conceptual design report was recently published as a CERN yellow report. In this seminar, I will review the conclusions of this report, focussing on four main areas. Firstly, I will give an overview of the physics potential at CLIC, and will place this in the context of a possible scenario for the staged construction of the machine. Secondly, I will discuss the challenges for a detector operating in the CLIC machine environment. I will then present detailed studies of possible detector concepts, based on high granularity particle flow calorimetry, which demonstrate that the required detector performance goals at CLIC can be met. Finally, I will highlight the main issues for the future R&a...

Experimental Study of the Effect of Beam Loading on RF Breakdown Rate in CLIC High-Gradient Accelerating Structures

CERN Document Server

Tecker, F; Kelisani, M; Doebert, S; Grudiev, A; Quirante, J; Riddone, G; Syratchev, I; Wuensch, W; Kononenko, O; Solodko, A; Lebet, S

2013-01-01

RF breakdown is a key issue for the multi-TeV highluminosity e+e- Compact Linear Collider (CLIC). Breakdowns in the high-gradient accelerator structures can deflect the beam and decrease the desired luminosity. The limitations of the accelerating structures due to breakdowns have been studied so far without a beam present in the structure. The presence of the beam modifies the distribution of the electrical and magnetic field distributions, which determine the breakdown rate. Therefore an experiment has been designed for high power testing a CLIC prototype accelerating structure with a beam present in the CLIC Test Facility (CTF3). A special beam line allows extracting a beam with nominal CLIC beam current and duration from the CTF3 linac. The paper describes the beam optics design for this experimental beam line and the commissioning of the experiment with beam.

From glutathione transferase to pore in a CLIC

CERN Document Server

Cromer, B A; Morton, C J; Parker, M W; 10.1007/s00249-002-0219-1

2002-01-01

Many plasma membrane chloride channels have been cloned and characterized in great detail. In contrast, very little is known about intracellular chloride channels. Members of a novel class of such channels, called the CLICs (chloride intracellular channels), have been identified over the last few years. A striking feature of the CLIC family of ion channels is that they can exist in a water- soluble state as well as a membrane-bound state. A major step forward in understanding the functioning of these channels has been the recent crystal structure determination of one family member, CLIC1. The structure confirms that CLICs are members of the glutathione S- transferase superfamily and provides clues as to how CLICs can insert into membranes to form chloride channels. (69 refs).

CLIC CDR - physics and detectors: CLIC conceptual design report.

Energy Technology Data Exchange (ETDEWEB)

Berger, E.; Demarteau, M.; Repond, J.; Xia, L.; Weerts, H. (High Energy Physics); (Many)

2012-02-10

This report forms part of the Conceptual Design Report (CDR) of the Compact LInear Collider (CLIC). The CLIC accelerator complex is described in a separate CDR volume. A third document, to appear later, will assess strategic scenarios for building and operating CLIC in successive center-of-mass energy stages. It is anticipated that CLIC will commence with operation at a few hundred GeV, giving access to precision standard-model physics like Higgs and top-quark physics. Then, depending on the physics landscape, CLIC operation would be staged in a few steps ultimately reaching the maximum 3 TeV center-of-mass energy. Such a scenario would maximize the physics potential of CLIC providing new physics discovery potential over a wide range of energies and the ability to make precision measurements of possible new states previously discovered at the Large Hadron Collider (LHC). The main purpose of this document is to address the physics potential of a future multi-TeV e{sup +}e{sup -} collider based on CLIC technology and to describe the essential features of a detector that are required to deliver the full physics potential of this machine. The experimental conditions at CLIC are significantly more challenging than those at previous electron-positron colliders due to the much higher levels of beam-induced backgrounds and the 0.5 ns bunch-spacing. Consequently, a large part of this report is devoted to understanding the impact of the machine environment on the detector with the aim of demonstrating, with the example of realistic detector concepts, that high precision physics measurements can be made at CLIC. Since the impact of background increases with energy, this document concentrates on the detector requirements and physics measurements at the highest CLIC center-of-mass energy of 3 TeV. One essential output of this report is the clear demonstration that a wide range of high precision physics measurements can be made at CLIC with detectors which are challenging, but

Finite Element Model for Thermal-Structural analysis of CLIC Lab Module type 0#2

CERN Document Server

Moilanen, Antti; Vamvakas, Alex; Vainola, Jukka Ilmari; Doebert, Steffen

2017-01-01

Temperature changes lead to unwanted thermo-mechanical deformations in the components of the Compact Linear Collider (CLIC) module. There are several sources and sinks of heat around the CLIC two-beam module. Heat is generated in the components that produce, transfer, and extract radio frequency (RF) power. Excess heat is removed from the components by cooling water as well as dissipated to air by convection from the outer surfaces of the components. The ambient temperature might also vary along the tunnel during the operation of CLIC. Due to tight assembling and alignment tolerances, it is necessary to minimize the thermo-mechanical deformations in the components. In this paper, the steps of thermal-structural Finite Element Analysis (FEA) of CLIC lab module type 0#2 are described from geometry model simplification to setting up the simulation. The description is accompanied by useful hints for CATIA and ANSYS users performing similar modelling tasks. A reliable computer simulation is important for studying ...

Thermo-structural analysis of the rf-induced pulsed surface heating of the CLIC accelerating structures

CERN Document Server

Huopana, Jouni Juhani

2006-01-01

The CLIC (Compact LInear Collider) is being studied at CERN as a potential multi-TeV e+e- collider. The acceleration of the particles is done by RF (Radio Frequency). The surfaces of the RF (radio frequency) accelerating cavities are exposed to high pulsed RF currents which induce cyclic thermal stresses. These cyclic stresses are crucial for the fatigue lifetime of the cavities. To study the fatigue phenomenon properly the induced stresses must be well known. ANSYS FEM simulations were made to study the thermo-structural behaviour of the CLIC accelerating structure in copper zirconium, bimetallic and diamond coated constructions. The simulations showed the existence of high thermal stresses and low stress level shockwaves. It was also shown that the bimetallic structure increases stress values due to the differences in material properties. Diamond coating was found to reduce the thermal stresses.

CLIC Physics Potential

CERN Document Server

Pandurovic, Mila

2017-01-01

The CLICdp is an international collaboration that investigates the physics potential of the Compact Linear Collider (CLIC) and performs research and development of the CLIC detector. CLIC is a future multi-TeV linear electron-positron collider, designed to cover a physics program of the Standard model physics, with the emphasis on Higgs and top as well as to address the wide range of open questions of the phenomena beyond the Standard model with high precision. The CLIC is designed to be build and operated at three discrete energy stages, sort(s) = 380 GeV, 1.5 and 3.0 TeV, which are optimized for the foreseen physics program. In this talk the CLIC accelerator, detector and experimental environment of CLIC will be presented, as well as, the number of the full-simulation measurements in the Higgs, top and beyond Standard model sector, presenting the capabilities of CLIC for high precision measurements.

Wakefield monitor development for CLIC accelerating structure

CERN Document Server

Peauger, F; Girardot, P; Andersson, A; Riddone, G; Samoshkin, A; Solodko, A; Zennaro, R; Ruber, R

2010-01-01

Abstract To achieve high luminosity in CLIC, the accelerating structures must be aligned to an accuracy of 5 μm with respect to the beam trajectory. Position detectors called Wakefield Monitors (WFM) are integrated to the structure for a beam based alignment. This paper describes the requirements of such monitors. Detailed RF design and electromagnetic simulations of the WFM itself are presented. In particular, time domain computations are performed and an evaluation of the resolution is done for two higher order modes at 18 and 24 GHz. The mechanical design of a prototype accelerating structure with WFM is also presented as well as the fabrication status of three complete structures. The objective is to implement two of them in CTF3 at CERN for a feasibility demonstration with beam and high power rf.

Physics at CLIC

CERN Multimedia

CERN. Geneva

2017-01-01

The Compact Linear Collider (CLIC) is a high-energy e+e- collider under development. The CLIC conceptual design report, published in 2012, concentrated on 3 TeV centre-of-mass energy. At that time operation at lower energies was not yet studied at the same level. Following the discovery of the Higgs boson, the CLIC potential for precision Higgs measurements was addressed for several centre-of-mass energies. In parallel, the scope for precision top quark physics was further explored. As a result an optimised CLIC staging scenario was defined in collaboration between accelerator and detector experts. The staging scenario aims at a maximum physics output and maximum luminosity yield with a collider built and operated in three energy steps: 380 GeV, 1.5 TeV, 3 TeV. The seminar will comprise a short status report on the CLIC accelerator and detector. Emphasis will be on the CLIC physics potential for Higgs, top quark and BSM physics in the new staging scenario.

Material studies in the frame of CLIC Accelerating structures production conducted within the Mechanics program together with Metso Oy

CERN Document Server

Nurminen, Janne

2012-01-01

MeChanICs (Marie Curie Linking Industry to CERN) is an Industry to Academia Partnership and Pathways (IAPP) platform for precision manufacturing knowledge exchange bringing together five Finnish manufacturing companies with Helsinki Insitute of Physics (HIP) and CERN. The scientific objective of MeChanICs project is to contribute to the manufacturing RTD of CLIC enabling technologies. The focus is on the design, materials, machining, brazing and assembly of A CLIC accelerating structure. This study deals with the materials work package of the program and wants to explore the following items: 1) producing copper accelerating structures for CLIC from raw copper powder by near net shape hot isostatic pressing (HIP). 2) The feasibility to use HIP diffusion bonding of the accelerator structures as a function of surface quality and applied temperature and pressure. 3) Brazing for CLIC AS auxiliary systems, like water cooling or damping manifolds, to the disc stack by coating one of the brazing partners with an enab...

Particle Identification algorithm for the CLIC ILD and CLIC SiD detectors

CERN Document Server

Nardulli, J

2011-01-01

This note describes the algorithm presently used to determine the particle identification performance for single particles for the CLIC ILD and CLIC SiD detector concepts as prepared in the CLIC Conceptual Design Report.

Standardization of the Experimental Methodology for Quality Assurance and Quality Control (QA-QC of the CLIC Structural Materials

Directory of Open Access Journals (Sweden)

N. Gazis

2015-04-01

Full Text Available The main linear accelerators (linacs of the Compact LInear Collider (CLIC are constituted of sequential two-beam modules (of approximate length of two meters. The CLIC linacs need to be firmly stabilized on their supports with a micron-level requirement, essential for maintaining the final target luminosity close to the required XXX value. Real scale two-beam prototype modules have been designed, manufactured and commissioned to study their behaviour under different operation modes and experimental conditions. The CLIC machine will work for continuous runs under conditions of high radiation background. The structural materials of the systems of the accelerator have to sustain the significant fatigue and activation due to the radiation, generated mainly by the losses of the particle beam. Extensive testing has taken place with a combination of mechanical experiments and irradiation sessions on samples of structural materials, focusing on the micro-precise CLIC module supporting system. The followed experimentally strategy was standardized in a series of sequential steps.

CLIC Test Facility 3

CERN Multimedia

Kossyvakis, I; Faus-golfe, A

2007-01-01

The design of CLIC is based on a two-beam scheme, where short pulses of high power 30 GHz RF are extracted from a drive beam running parallel to the main beam. The 3rd generation CLIC Test Facility (CTF3) will demonstrate the generation of the drive beam with the appropriate time structure, the extraction of 30 GHz RF power from this beam, as well as acceleration of a probe beam with 30 GHz RF cavities. The project makes maximum use of existing equipment and infrastructure of the LPI complex, which became available after the closure of LEP.

CLIC Project Overview (In Conjunction with the Muon Collider Workshop)

International Nuclear Information System (INIS)

Latina, Andrea

2009-01-01

The CLIC study is exploring the scheme for an electron-positron collider with a centre-of-mass energy of 3 TeV in order to make the multi-TeV range accessible for physics. The current goal of the project is to demonstrate the feasibility of the technology by the year 2010. Recently, important progress has been made concerning the high-gradient accelerating structure tests and the experiments with beam in the CLIC test facility, CTF3. On the organizational side, the CLIC international collaborations have significantly gained momentum, boosting the CLIC study.

Particle mis-identification rate algorithm for the CLIC ILD and CLIC SiD detectors

CERN Document Server

Nardulli, J

2011-01-01

This note describes the algorithm presently used to determine the particle mis- identification rate and gives results for single particles for the CLIC ILD and CLIC SiD detector concepts as prepared for the CLIC Conceptual Design Report.

Technological challenges of CLIC

CERN Multimedia

CERN. Geneva; Döbert, Steffen; Arnau-Izquierdo, G; Redaelli, Stefano; Mainaud, Helène; Lefèvre, Thibaut

2006-01-01

Future e+e- Linear Colliders offer the potential to explore new physics at the TeV scale and beyond to very high precision. While the International Linear Collider (ILC) scheme of a collider in the 0.5 - 1 TeV range enters the engineering design phase, the Compact Linear Collider (CLIC) study explores the technical feasibility of a collider capable of reaching into the multi-TeV energy domain. Key ingredients of the CLIC scheme are acceleration at high-frequency (30 GHz) and high-gradient (150 MV/m) in normal conducting structures and the use of the so-called Two Beam Acceleration concept, where a high-charge electron beam (drive beam) running parallel to the main beam is decelerated to provide the RF power to accelerate the main beam itself. A vigorous R&D effort is presently developed by the CLIC international collaboration to demonstrate its feasibility by 2010, when the first physics results from LHC should be available to guide the choice of the centre-of-mass energy better suited to explore the futu...

Experimental study of DC vacuum breakdown and application to high-gradient accelerating structures for CLIC

CERN Document Server

Shipman, Nicholas; Jones, Roger

2016-01-01

The compact linear collider (CLIC) is a leading candidate for the next generation high energy linear collider. As any breakdown would result in a partial or full loss of luminosity for the pulse in which it occurs, obtaining a low breakdown rate in CLIC accelerating structures is a critical requirement for the successful operation of the proposed collider. This thesis presents investigations into the breakdown phenomenon primarily in the low breakdown rate regime of interest to CLIC, performed using the CERN DC spark systems between 2011 and 2014. The design, construction and commissioning of several new pieces of hardware, as well as the development of improved techniques to measuring the inter-electrode gap distance are detailed. These hardware improvements were fundamental in enabling the exciting new experiments mentioned below, which in turn have provided significant additional insight into the phenomenon of breakdown. Experiments were performed to measure fundamental parameters of individual breakdowns...

High Field Studies for CLIC Accelerating Structures Development

CERN Document Server

Profatilova, I

2017-01-01

Compact Linear Collider RF structures need to be able to achieve the very high average accelerating gradient of 100 MV/m. One of the main challenges in reaching such high accelerating gradients is to avoid vacuum electrical breakdown within CLIC accelerating structures. Accelerating structure tests are carried out in the klystron-based test stands known as the XBoxes. In order to investigate vacuum breakdown phenomena and its statistical characteristics in a simpler system and get results in a faster way, pulsed dc systems have been developed at CERN. To acquire sufficient breakdown data in a reasonable period of time, high repetition rate pulse generators are used in the systems for breakdown studies, so-called pulsed dc system. This paper describes the pulsed dc systems and the two high repetition rate circuits, which produce high-voltage pulses for it, available at CERN.

CLIC: Status and Plan

CERN Document Server

Sailer, Andre

2014-01-01

The Compact Linear Collider (CLIC) is a high energy electron–positron col- lider with a maximal centre-of-mass energy of 3 TeV. In order to achieve high luminosity small bunches with high intensity are necessary. These lead to strong beam-beam forces, which create a challenging background environment. The accelerator concept and the detectors designed for CLIC are presented. Results from detector benchmark studies presented in the CLIC conceptual design report are summarised.

Status of Wakefield Monitor Experiments at the CLIC Test Facility

CERN Document Server

Lillestøl, Reidar; Aftab, Namra; Corsini, Roberto; Döbert, Steffen; Farabolini, Wilfrid; Grudiev, Alexej; Javeed, Sumera; Pfingstner, Juergen; Wuensch, Walter

2016-01-01

For the very low emittance beams in CLIC, it is vital to mitigate emittance growth which leads to reduced luminosity in the detectors. One factor that leads to emittance growth is transverse wakefields in the accelerating structures. In order to combat this the structures must be aligned with a precision of a few um. For achieving this tolerance, accelerating structures are equipped with wakefield monitors that measure higher-order dipole modes excited by the beam when offset from the structure axis. We report on such measurements, performed using prototype CLIC accelerating structures which are part of the module installed in the CLIC Test Facility 3 (CTF3) at CERN. Measurements with and without the drive beam that feeds rf power to the structures are compared. Improvements to the experimental setup are discussed, and finally remaining measurements that should be performed before the completion of the program are summarized.

Oxidation promotes insertion of the CLIC1 chloride intracellular channel into the membrane.

Science.gov (United States)

Goodchild, Sophia C; Howell, Michael W; Cordina, Nicole M; Littler, Dene R; Breit, Samuel N; Curmi, Paul M G; Brown, Louise Jennifer

2009-12-01

Members of the chloride intracellular channel (CLIC) family exist primarily as soluble proteins but can also auto-insert into cellular membranes to form ion channels. While little is known about the process of CLIC membrane insertion, a unique feature of mammalian CLIC1 is its ability to undergo a dramatic structural metamorphosis between a monomeric glutathione-S-transferase homolog and an all-helical dimer upon oxidation in solution. Whether this oxidation-induced metamorphosis facilitates CLIC1 membrane insertion is unclear. In this work, we have sought to characterise the role of oxidation in the process of CLIC1 membrane insertion. We examined how redox conditions modify the ability of CLIC1 to associate with and insert into the membrane using fluorescence quenching studies and a sucrose-loaded vesicle sedimentation assay to measure membrane binding. Our results suggest that oxidation of monomeric CLIC1, in the presence of membranes, promotes insertion into the bilayer more effectively than the oxidised CLIC1 dimer.

A Multi-TeV Linear Collider Based on CLIC Technology

Energy Technology Data Exchange (ETDEWEB)

Aicheler, M [European Organ. ization for Nuclear Research, Geneva (Switzerland); Burrows, P [Oxford University (United Kingdom); Draper, M; Garvey, T; Lebrun, P [European Organization for Nuclear Research, Geneva (Switzerland); Peach, K [Oxford University (United Kingdom); Phinney, N [SLAC (United States); Schmickler, H; Schulte, D [European Organization for Nuclear Research, Geneva (Switzerland); Toge, N [KEK, Tsukuba (Japan)

2012-07-01

This report describes the accelerator studies for a future multi-TeV e+e- collider based on the Compact Linear Collider (CLIC) technology. The CLIC concept as described in the report is based on high gradient normal-conducting accelerating structures where the RF power for the acceleration of the colliding beams is extracted from a high-current Drive Beam that runs parallel with the main linac. The focus of CLIC R&D over the last years has been on addressing a set of key feasibility issues that are essential for proving the fundamental validity of the CLIC concept. The status of these feasibility studies are described and summarized. The report also includes a technical description of the accelerator components and R&D to develop the most important parts and methods, as well as a description of the civil engineering and technical services associated with the installation. Several larger system tests have been performed to validate the two-beam scheme, and of particular importance are the results from the CLIC test facility at CERN (CTF3). Both the machine and detector/physics studies for CLIC have primarily focused on the 3 TeV implementation of CLIC as a benchmark for the CLIC feasibility. This report also includes specific studies for an initial 500 GeV machine, and some discussion of possible intermediate energy stages. The performance and operation issues related to operation at reduced energy compared to the nominal, and considerations of a staged construction program are included in the final part of the report. The CLIC accelerator study is organized as an international collaboration with 43 partners in 22 countries. An associated report describes the physics potential and experiments at CLIC and a shorter report in preparation will focus on the CLIC implementation strategy, together with a plan for the CLIC R&D studies 2012–2016. Critical and important implementation issues such as cost, power and schedule will be addressed there. (author)

A Multi-TeV Linear Collider Based on CLIC Technology

International Nuclear Information System (INIS)

Aicheler, M; Burrows, P; Draper, M; Garvey, T; Lebrun, P; Peach, K; Phinney, N; Schmickler, H; Schulte, D; Toge, N

2012-01-01

This report describes the accelerator studies for a future multi-TeV e+e- collider based on the Compact Linear Collider (CLIC) technology. The CLIC concept as described in the report is based on high gradient normal-conducting accelerating structures where the RF power for the acceleration of the colliding beams is extracted from a high-current Drive Beam that runs parallel with the main linac. The focus of CLIC R&D over the last years has been on addressing a set of key feasibility issues that are essential for proving the fundamental validity of the CLIC concept. The status of these feasibility studies are described and summarized. The report also includes a technical description of the accelerator components and R&D to develop the most important parts and methods, as well as a description of the civil engineering and technical services associated with the installation. Several larger system tests have been performed to validate the two-beam scheme, and of particular importance are the results from the CLIC test facility at CERN (CTF3). Both the machine and detector/physics studies for CLIC have primarily focused on the 3 TeV implementation of CLIC as a benchmark for the CLIC feasibility. This report also includes specific studies for an initial 500 GeV machine, and some discussion of possible intermediate energy stages. The performance and operation issues related to operation at reduced energy compared to the nominal, and considerations of a staged construction program are included in the final part of the report. The CLIC accelerator study is organized as an international collaboration with 43 partners in 22 countries. An associated report describes the physics potential and experiments at CLIC and a shorter report in preparation will focus on the CLIC implementation strategy, together with a plan for the CLIC R&D studies 2012–2016. Critical and important implementation issues such as cost, power and schedule will be addressed there. (author)

Particle Identification performance for leptons in jets for the CLIC ILD and CLIC SiD detectors

CERN Document Server

Nardulli, J

2011-01-01

This note describes the particle identification performance for particles in jets for the CLIC ILD and CLIC SiD detector concepts as prepared in the CLIC Conceptual Design Report. The results are presented with and without the presence of the γγ → hadrons background events.

Physics and Detectors at CLIC CLIC Conceptual Design Report

CERN Document Server

Miyamoto, Akiya; Stanitzki,Marcel; Weerts, Harry

2012-01-01

This report describes the physics potential and experiments at a future multi- TeV e+e− collider based on the Compact Linear Collider (CLIC) technology. The physics scenarios considered include precision measurements of known quantities as well as the discovery potential of physics beyond the Standard Model. The report describes the detector performance required at CLIC, taking into account the interaction point environment and especially beaminduced backgrounds. Two detector concepts, designed around highly granular calorimeters and based on concepts studied for the International Linear Collider (ILC), are described and used to study the physics reach and potential of such a collider. Detector subsystems and the principal engineering challenges are illustrated. The overall performance of these CLIC detector concepts is demonstrated by studies of the performance of individual subdetector systems as well as complete simulation studies of six benchmark physics processes. These full detector simulation and rec...

Experimental verification of the CLIC Decelerator with the test Beam Line in the CLIC test facility 3

CERN Document Server

Lillestøl, R L; Olvegård, M; Rabiller, A N; Sterbini, G; Adli, E

2012-01-01

The Test Beam Line in the CLIC Test Facility 3 is the first prototype of the CLIC drive beam decelerator. The main purpose of the experiment is to demonstrate efficient 12 GHz rf power production and stable transport of an electron drive beam during deceleration. The Test Beam Line consists of a FODO structure with high precision BPMs and quadrupoles mounted on mechanical movers for precisebeam alignment. Nine out of the planned 16 Power Extraction and Transfer Structures have currently been installed and commissioned. We correlate rf power production measurements with the drive beam deceleration measurements, and compare the two measurements to the theoretical predictions. We also discuss the impact of the drive beam bunch length and bunch combination on the measurements.

A New Damped and Tapered Accelerating Structure for CLIC

CERN Document Server

Raguin, J Y; Syratchev, I V; Wilson, Ian H; Wuensch, Walter

2002-01-01

The main performance limits when designing accelerating structures for the Compact Linear Collider (CLIC) for an average accelerating gradient above 100 MV/m are electrical breakdown and material fatigue caused by pulsed surface heating. In addition, for stable beam operation, the structures should have low short-range transverse wakefields and much-reduced transverse and longitudinal long-range wakefields. Two damped and tapered accelerating structures have been designed. The first has an accelerating gradient of 112 MV/m with the surface electrical field limited to 300 MV/m and the maximum temperature increase limited to 100°C. The second, with an accelerating gradient of 150 MV/m, has a peak surface electrical field of 392 MV/m and a maximum temperature increase of 167°C. Innovations to the cell and damping waveguide geometry and to the tapering of the structures are presented, and possible further improvements are proposed.

A 12 GHz RF Power Source for the CLIC Study

Energy Technology Data Exchange (ETDEWEB)

Schirm, Karl; /CERN; Curt, Stephane; /CERN; Dobert, Steffen; /CERN; McMonagle, Gerard; /CERN; Rossat, Ghislain; /CERN; Syratchev, Igor; /CERN; Timeo, Luca; /CERN; Haase, Andrew /SLAC; Jensen, Aaron; /SLAC; Jongewaard, Erik; /SLAC; Nantista, Christopher; /SLAC; Sprehn, Daryl; /SLAC; Vlieks, Arnold; /SLAC; Hamdi, Abdallah; /Saclay; Peauger, Franck; /Saclay; Kuzikov, Sergey; /Nizhnii Novgorod, IAP; Vikharev, Alexandr; /Nizhnii Novgorod, IAP

2012-07-03

The CLIC RF frequency has been changed in 2008 from the initial 30 GHz to the European X-band 11.9942 GHz permitting beam independent power production using klystrons for CLIC accelerating structure testing. A design and fabrication contract for five klystrons at that frequency has been signed by different parties with SLAC. France (IRFU, CEA Saclay) is contributing a solid state modulator purchased in industry and specific 12 GHz RF network components to the CLIC study. RF pulses over 120 MW peak at 230 ns length will be obtained by using a novel SLED-I type pulse compression scheme designed and fabricated by IAP, Nizhny Novgorod, Russia. The X-band power test stand is being installed in the CLIC Test Facility CTF3 for independent structure and component testing in a bunker, but allowing, in a later stage, for powering RF components in the CTF3 beam lines. The design of the facility, results from commissioning of the RF power source and the expected performance of the Test Facility are reported.

A 12 GHZ RF Power source for the CLIC study

CERN Document Server

Peauger, F; Curt, S; Doebert, S; McMonagle, G; Rossat, G; Schirm, KM; Syratchev, I; Timeo, L; Kuzikhov, S; Vikharev, AA; Haase, A; Sprehn, D; Jensen, A; Jongewaard, EN; Nantista, CD; Vlieks, A

2010-01-01

The CLIC RF frequency has been changed in 2008 from the initial 30 GHz to the European X-band 11.9942 GHz permitting beam independent power production using klystrons for CLIC accelerating structure testing. A design and fabrication contract for five klystrons at that frequency has been signed by different parties with SLAC. France (IRFU, CEA Saclay) is contributing a solid state modulator purchased in industry and specific 12 GHz RF network components to the CLIC study. RF pulses over 120 MW peak at 230 ns length will be obtained by using a novel SLED-I type pulse compression scheme designed and fabricated by IAP, Nizhny Novgorod, Russia. The X-band power test stand is being installed in the CLIC Test Facility CTF3 for independent structure and component testing in a bunker, but allowing, in a later stage, for powering RF components in the CTF3 beam lines. The design of the facility, results from commissioning of the RF power source and the expected performance of the Test Facility are reported.

Detector Systems at CLIC

CERN Document Server

Simon, Frank

2011-01-01

The Compact Linear Collider CLIC is designed to deliver e+e- collisions at a center of mass energy of up to 3 TeV. The detector systems at this collider have to provide highly efficient tracking and excellent jet energy resolution and hermeticity for multi-TeV final states with multiple jets and leptons. In addition, the detector systems have to be capable of distinguishing physics events from large beam-induced background at a crossing frequency of 2 GHz. Like for the detector concepts at the ILC, CLIC detectors are based on event reconstruction using particle flow algorithms. The two detector concepts for the ILC, ILD and SID, were adapted for CLIC using calorimeters with dense absorbers limiting leakage through increased compactness, as well as modified forward and vertex detector geometries and precise time stamping to cope with increased background levels. The overall detector concepts for CLIC are presented, with particular emphasis on the main detector and engineering challenges, such as: the ultra-thi...

Assembly Test of Elastic Averaging Technique to Improve Mechanical Alignment for Accelerating Structure Assemblies in CLIC

CERN Document Server

Huopana, J

2010-01-01

The CLIC (Compact LInear Collider) is being studied at CERN as a potential multi-TeV e+e- collider [1]. The manufacturing and assembly tolerances for the required RF-components are important for the final efficiency and for the operation of CLIC. The proper function of an accelerating structure is very sensitive to errors in shape and location of the accelerating cavity. This causes considerable issues in the field of mechanical design and manufacturing. Currently the design of the accelerating structures is a disk design. Alternatively it is possible to create the accelerating assembly from quadrants, which favour the mass manufacturing. The functional shape inside of the accelerating structure remains the same and a single assembly uses less parts. The alignment of these quadrants has been previously made kinematic by using steel pins or spheres to align the pieces together. This method proved to be a quite tedious and time consuming method of assembly. To limit the number of different error sources, a meth...

Results from the CLIC Test Facility

CERN Document Server

Braun, H; Bossart, Rudolf; Chautard, F; Corsini, R; Delahaye, J P; Godot, J C; Hutchins, S; Kamber, I; Madsen, J H B; Rinolfi, Louis; Rossat, G; Schreiber, S; Suberlucq, Guy; Thorndahl, L; Wilson, Ian H; Wuensch, Walter

1996-01-01

In order to study the principle of the Compact Linear Collider (CLIC) based on the Two Beam Acceleration (TBA) scheme at high frequency, a CLIC Test Facility (CTF) has been set-up at CERN. After four years of successful running, the experimental programme is now fully completed and all its objectives reached, particularly the generation of a high intensity drive beam with short bunches by a photo-injector, the production of 30 GHz RF power and the acceleration of a probe beam by 30 GHz structures. A summary of the CTF results and their impact on linear collider design is given. This covers 30 GHz high power testing, study of intense, short single bunches; as well as RF-Gun, photocathode and beam diagnostic developments. A second phase of the test facility (CTF2) is presently being installed to demonstrate the feasibility of the TBA scheme by constructing a fully engineered, 10 m long, test section very similar to the CLIC drive and main linacs, producing up to 480 MW of peak RF power at 30 GHz and acceleratin...

Academic Training - Technological challenges of CLIC

CERN Multimedia

Françoise Benz

2006-01-01

2005-2006 ACADEMIC TRAINING PROGRAMME LECTURE SERIES 12, 13, 14, 15 and 16 June 11:00-12:00 - Auditorium, bldg 500 Technological challenges of CLIC R. Corsini, S. Doebert, S. Redaelli, T.Lefevre, CERN-AB and G. Arnau Izquierdo, H. Mainaud, CERN-TS Future e+e- Linear Colliders offer the potential to explore new physics at the TeV scale and beyond to very high precision. While the International Linear Collider (ILC) scheme of a collider in the 0.5 - 1 TeV range enters the engineering design phase, the Compact Linear Collider (CLIC) study explores the technical feasibility of a collider capable of reaching into the multi-TeV energy domain. Key ingredients of the CLIC scheme are acceleration at high-frequency (30 GHz) and high-gradient (150 MV/m) in normal conducting structures and the use of the so-called Two Beam Acceleration concept, where a high-charge electron beam (drive beam) running parallel to the main beam is decelerated to provide the RF power to accelerate the main beam itself. A vigorous R&...

CLIC: developing a linear collider

CERN Multimedia

Laurent Guiraud

1999-01-01

Compact Linear Collider (CLIC) is a CERN project to provide high-energy electron-positron collisions. Instead of conventional radio-frequency klystrons, CLIC will use a low-energy, high-intensity primary beam to produce acceleration.

Preparing for CLIC tests

CERN Multimedia

Laurent Guiraud

1999-01-01

The Canon 5 undergoes first brazing for preparation in the CLIC study at the CLIC Test Facility 2 (CTF2). This will test injection for a proposed linear collider that will further explore discoveries made at the LHC. Electric fields in the canon will boost electrons into the acceleration fields of the collider.

CLIC expands to include the Southern Hemisphere

CERN Multimedia

Roberto Cantoni

2010-01-01

Australia has recently joined the CLIC collaboration: the enlargement will bring new expertise and resources to the project, and is especially welcome in the wake of CERN budget redistributions following the recent adoption of the Medium Term Plan.   The countries involved in CLIC collaboration With the signing of a Memorandum of Understanding on 26 August 2010, the ACAS network (Australian Collaboration for Accelerator Science) became the 40th member of in the multilateral CLIC collaboration making Australia the 22nd country to join the collaboration. “The new MoU was signed by the ACAS network, which includes the Australian Synchrotron and the University of Melbourne”, explains Jean-Pierre Delahaye, CLIC Study Leader. “Thanks to their expertise, the Australian institutes will contribute greatly to the CLIC damping rings and the two-beam test modules." Institutes from any country wishing to join the CLIC collaboration are invited to assume responsibility o...

Overview of CLIC and CTF3

CERN Document Server

Corsini, R

2002-01-01

The CLIC study aims at the design of a high-energy (0.5-5 TeV), high luminosity e+e- linear collider, as a possible facility for the post-LHC era. The beams are accelerated using high-frequency (30 GHz) normal-conducting structures operating at high accelerating gradients to reduce the length and, in consequence, the cost of the linac. The RF power for these structures is generated using the so-called Two-Beam Acceleration (TBA) scheme, where a low-energy, high-intensity electron beam (drive beam) runs parallel to the main linacs and is decelerated in resonant structures, which extract RF power from the drive beam. The drive beam is first accelerated in a low-frequency fully-loaded normal-conducting linac. Its time structure is then obtained by funneling in isochronous rings using transverse RF deflectors. CTF3, a new generation CLIC Test Facility, is being built at CERN to demonstrate the technical feasibility of this novel drive beam generation and RF power production scheme, albeit on a much smaller scale....

Flow induced vibrations of the CLIC X-Band accelerating structures

CERN Document Server

Charles, Tessa; Boland, Mark; Riddone, Germana; Samoshkin, Alexandre

2011-01-01

Turbulent cooling water in the Compact Linear Collider (CLIC) accelerating structures will inevitably induce some vibrations. The maximum acceptable amplitude of vibrations is small, as vibrations in the accelerating structure could lead to beam jitter and alignment difficulties. A Finite Element Analysis model is needed to identify the conditions under which turbulent instabilities and significant vibrations are induced. Due to the orders of magnitude difference between the fluid motion and the structure’s motion, small vibrations of the structure will not contribute to the turbulence of the cooling fluid. Therefore the resonant conditions of the cooling channels presented in this paper, directly identify the natural frequencies of the accelerating structures to be avoided under normal operating conditions. In this paper a 2D model of the cooling channel is presented finding spots of turbulence being formed from a shear layer instability. This effect is observed through direct visualization and wavelet ana...

Material studies for CLIC RF cavities

CERN Document Server

Taborelli, M

2004-01-01

Following the EST/SM suggestion of replacing copper by molybdenum or tungsten for the construction of the RF cavity irises, different CLIC main beam accelerating structures were produced, extensively operated and disassembled for iris surface inspection. The observed surface modifications were found to be very similar to those obtained by sparking in a dedicated laboratory set-up, showing the superior behaviour of both Mo and W with respect to Cu, in terms of surface erosion and conditioning. The iris thermomechanical fatigue due to RF heating was simulated by high power pulsed laser irradiation. A CuZr alloy was found to be much more resistant than pure Cu. Measurements at higher pulse number will be performed on CuZr in order to extrapolate its fatigue behaviour up to the nominal CLIC duration. Finally a possible future development of a hybrid probe beam acceleration structure will be presented.

CLIC Quadrupole Module final report

CERN Document Server

Artoos, K; Mainaud-Durand, H

2013-01-01

Future Linear colliders will need particle beam sizes in the nanometre range. The beam also needs to be stable all along the beam line. The CLIC Main Beam Quadrupole (MBQ) module has been defined and studied. It is meant as a test stand for stabilisation and pre-alignment with a MB Quadrupole. The main topic that has been tackled concerns the Quadrupole magnet stabilisation to 1nm at 1Hz. This is needed to obtain the desired CLIC luminosity of 2.1034 cm-2m-1. The deliverable was demonstrated by procuring a MBQ and by stabilising a powered and cooled CLIC MBQ quadrupole. In addition, the stabilisation system has to be compatible with the pre-alignment procedures. Pre-alignment movement resolution has been demonstrated to 1m. The last step is the combined test of stability with a quadrupole on a CLIC Module with the pre-alignment.

CLIC Detector and Physics Status

CERN Document Server

AUTHOR|(SzGeCERN)627941

2017-01-01

This contribution to LCWS2016 presents recent developments within the CLICdp collaboration. An updated scenario for the staged operation of CLIC has been published; the accelerator will operate at 380 GeV, 1.5 TeV and 3 TeV. The lowest energy stage is optimised for precision Higgs and top physics, while the higher energy stages offer extended Higgs and BSM physics sensitivity. The detector models CLIC_SiD and CLIC_ILD have been replaced by a single optimised detector; CLICdet. Performance studies and R&D in technologies to meet the requirements for this detector design are ongoing.

Physics Signatures at CLIC

CERN Document Server

Battaglia, Marco

2001-01-01

A set of signatures for physics processes of potential interests for the CLIC programme at = 1 - 5 TeV are discussed. These signatures, that may correspond to the manifestation of different scenarios of new physics as well as to Standard Model precision tests, are proposed as benchmarks for the optimisation of the CLIC accelerator parameters and for a first definition of the required detector response.

CLICdp Overview. Overview of physics potential at CLIC

Directory of Open Access Journals (Sweden)

Levy Aharon

2015-01-01

Full Text Available CLICdp, the CLIC detector and physics study, is an international collaboration presently composed of 23 institutions. The collaboration is addressing detector and physics issues for the future Compact Linear Collider (CLIC, a high-energy electron-positron accelerator which is one of the options for the next collider to be built at CERN. Precision physics under challenging beam and background conditions is the key theme for the CLIC detector studies. This leads to a number of cutting-edge R&D activities within CLICdp. The talk includes a brief introduction to CLIC, accelerator and detectors, hardware R&D as well as physics studies at CLIC.

Muon System Design Studies for Detectors at CLIC

CERN Document Server

van der Kraaij, E

2011-01-01

The two concepts for CLIC detectors inherited their design of the muon systems from the ILC community. In this note the outcome of a reevaluation of the design for the CLIC environment is presented. Based on a full detector simulation, the muon identification performance is analysed for different detector layouts and different cellsizes. As a result, nine layers are suggested for the muon systems of the CLIC ILD and CLIC SiD detectors, which are arranged in three groups of three layers. The cellsizes have been kept at 30×30 mm2. These layouts are used for the performance studies of the CLIC Conceptual Design Report (CDR).

CLIC brochure (English version)

CERN Multimedia

Lefevre, Christiane

2012-01-01

The world's biggest and most powerful accelerator, the LHC, is mapping the route of particle physics for the future. The next step, to complement the LHC in exploring this new region, is most likely to be a linear electron-positron collider. The Compact Linear Collider (CLIC) is a novel approach to such a collider. It is currently under development by the CLIC collaboration, which is hosted at CERN.

Acquisition system for the CLIC Module

CERN Document Server

Vilalte, Sebastien

2011-01-01

The status of R&D activities for CLIC module acquisition are discussed [1]. LAPP is involved in the design of the local CLIC module acquisition crate, described in the document Study of the CLIC Module Front-End Acquisition and Evaluation Electronics [2]. This acquisition system is a project based on a local crate, assigned to the CLIC module, including several mother boards. These motherboards are foreseen to hold mezzanines dedicated to the different subsystems. This system has to work in radiation environment. LAPP is involved in the development of Drive Beam stripline position monitors read-out, described in the document Drive Beam Stripline BPM Electronics and Acquisition [3]. LAPP also develops a generic acquisition mezzanine that allows to perform all-around acquisition and components tests for drive beam stripline BPM read-out.

Experimental Program for the CLIC test facility 3 test beam line

CERN Document Server

Adli, E; Dobert, S; Olvegaard, M; Schulte, D; Syratchev, I; Lillestol, Reidar

2010-01-01

The CLIC Test Facility 3 Test Beam Line is the first prototype for the CLIC drive beam decelerator. Stable transport of the drive beam under deceleration is a mandatory component in the CLIC two-beam scheme. In the Test Beam Line more than 50% of the total energy will be extracted from a 150 MeV, 28 A electron drive beam, by the use of 16 power extraction and transfer structures. A number of experiments are foreseen to investigate the drive beam characteristics under deceleration in the Test Beam Line, including beam stability, beam blow up and the efficiency of the power extraction. General benchmarking of decelerator simulation and theory studies will also be performed. Specially designed instrumentation including precision BPMs, loss monitors and a time-resolved spectrometer dump will be used for the experiments. This paper describes the experimental program foreseen for the Test Beam Line, including the relevance of the results for the CLIC decelerator studies.

Mechanical integration studies for the CLIC vertex and inner tracking detectors

CERN Document Server

Villarejo Bermudez, M.A.; Gerwig, H.

2015-01-01

Since the publication of the CLIC Conceptual Design Report, work has proceeded in order to establish a preliminary mechanical design for the innermost CLIC detector region. This note proposes a design for the main Carbon-Fibre Reinforced Polymer (CFRP) structural elements of the inner detectors, for the beam pipe and their supports. It also describes an assembly sequence for the integration of the sensors and the mechanical components. Mechanical simulations of different structural elements and a material budget estimation are appended. Details of a proposed cabling layout for all the subdetectors are included.

Numerical Verification of the Power Transfer and Wakefield Coupling in the CLIC Two-Beam Accelerator

CERN Document Server

Candel, Arno; NG, C; Rawat, V; Schussman, G; Ko, K; Syratchev, I; Grudiev, A; Wuensch, W

2011-01-01

The Compact Linear Collider (CLIC) provides a path to a multi-TeV accelerator to explore the energy frontier of High Energy Physics. Its two-beam accelerator (TBA) concept envisions complex 3D structures, which must be modeled to high accuracy so that simulation results can be directly used to prepare CAD drawings for machining. The required simulations include not only the fundamental mode properties of the accelerating structures but also the Power Extraction and Transfer Structure (PETS), as well as the coupling between the two systems. Time-domain simulations will be performed to understand pulse formation, wakefield damping, fundamental power transfer and wakefield coupling in these structures. Applying SLAC’s parallel finite element code suite, these large-scale problems will be solved on some of the largest supercomputers available. The results will help to identify potential issues and provide new insights on the design, leading to further improvements on the novel two-beam accelerator scheme.

CLIC transfer structure (CTS) simulations using open-quotes MAFIAclose quotes

International Nuclear Information System (INIS)

Millich, A.

1993-01-01

In the two-beam accelerator scheme of CLIC the Transfer Structure serves the purpose of extracting 30 GHz power from the drive beam. The purpose of the 3D simulations of the 30 GHz CTS using the MAFIA set of codes has been to assist the designers in the choice of the final dimensions by appreciating the sensitivity of the RF characteristics to the mechanical parameters. The results of the frequency domain analysis have allowed plotting of the dispersion curves of the waveguides and appreciation the relative importance of higher modes. The time domain investigations have produced results on the shape and magnitude of the beam-induced longitudinal and transverse wake fields and of the loss factors

CLIC Luminosity Monitoring

CERN Document Server

Apyan, Armen; Gschwendtner, Edda; Lefevre, Thibault; Tygier, Sam; Appleby, Robert B

2012-01-01

The CLIC post-collision line is designed to transport the un-collided beams and the products of the collided beams with a total power of 14 MW to the main beam dump. Luminosity monitoring for CLIC is based on high energy muons produced by beamstrahlung photons in the main dump. Threshold Cherenkov counters are proposed for the detection of these muons. The expected rates and layout for these detectors is presented. Another method for luminosity monitoring is to directly detect the beamstrahlung photons in the post-collision line. Full Monte Carlo simulation has been performed to address its feasibility.

Overview of the CLIC detector and its physics potential

CERN Document Server

AUTHOR|(SzGeCERN)786425

2016-01-01

The CLIC detector and physics study (CLICdp) is an international collaboration that investigates the physics potential of the Compact Linear Collider (CLIC). CLIC is a high-energy electron-positron collider under development, aiming for centre-of-mass energies from a few hundred GeV to 3 TeV. In addition to physics studies based on full Monte Carlo simulations of signal and background processes, CLICdp performs cutting-edge hardware R&D. In this contribution CLICdp will present recent results from physics prospect studies, emphasising Higgs studies. Additionally the new CLIC detector model and the recently updated CLIC baseline staging scenario will be presented.

Overview of the CLIC detector and its physics potential

Science.gov (United States)

Ström, Rickard

2017-12-01

The CLIC detector and physics study (CLICdp) is an international collaboration that investigates the physics potential of the Compact Linear Collider (CLIC). CLIC is a high-energy electron-positron collider under development, aiming for centre-of-mass energies from a few hundred GeV to 3 TeV. In addition to physics studies based on full Monte Carlo simulations of signal and background processes, CLICdp performs cuttingedge hardware R&D. In this contribution CLICdp will present recent results from physics prospect studies, emphasising Higgs studies. Additionally the new CLIC detector model and the recently updated CLIC baseline staging scenario will be presented.

Point mutations in the transmembrane region of the clic1 ion channel selectively modify its biophysical properties.

Directory of Open Access Journals (Sweden)

Stefania Averaimo

Full Text Available Chloride intracellular Channel 1 (CLIC1 is a metamorphic protein that changes from a soluble cytoplasmic protein into a transmembrane protein. Once inserted into membranes, CLIC1 multimerises and is able to form chloride selective ion channels. Whilst CLIC1 behaves as an ion channel both in cells and in artificial lipid bilayers, its structure in the soluble form has led to some uncertainty as to whether it really is an ion channel protein. CLIC1 has a single putative transmembrane region that contains only two charged residues: arginine 29 (Arg29 and lysine 37 (Lys37. As charged residues are likely to have a key role in ion channel function, we hypothesized that mutating them to neutral alanine to generate K37A and R29A CLIC1 would alter the electrophysiological characteristics of CLIC1. By using three different electrophysiological approaches: i single channel Tip-Dip in artificial bilayers using soluble recombinant CLIC1, ii cell-attached and iii whole-cell patch clamp recordings in transiently transfected HEK cells, we determined that the K37A mutation altered the single-channel conductance while the R29A mutation affected the single-channel open probability in response to variation in membrane potential. Our results show that mutation of the two charged amino acids (K37 and R29 in the putative transmembrane region of CLIC1 alters the biophysical properties of the ion channel in both artificial bilayers and cells. Hence these charged residues are directly involved in regulating its ion channel activity. This strongly suggests that, despite its unusual structure, CLIC1 itself is able to form a chloride ion channel.

Golden Jubilee Photos: A CLIC for the future

CERN Multimedia

2004-01-01

http://www.cern.ch/cern50/ Prototype copper accelerating structures for CLIC. New accelerator projects take many years to make and mature. When the LHC project was still only a twinkle in CERN's eye, research was already starting on a new machine. A small team at CERN was setting about the task of studying a high-energy, compact, lepton linear collider, known as CLIC. This is possibly set to become the collider of the future. A machine of this kind has all the advantages of a collider (the total collision energy is equal to the sum of the energies of the two colliding beams) without the drawback of synchrotron radiation, which is produced when particles are accelerated around a ring and thus puts a limit on the energy of such colliders. But in a project as technically challenging as CLIC, considerable technological hurdles must be overcome. To limit the linear collider's length to some tens of kilometres, the beams must acquire a considerable quantity of energy per metre travelled. The collision rate (lumi...

Vacuum arc localization in CLIC prototype radio frequency accelerating structures

CERN Document Server

AUTHOR|(CDS)2091976; Koivunen, Visa

2016-04-04

A future linear collider capable of reaching TeV collision energies should support accelerating gradients beyond 100 MV/m. At such high fields, the occurrence of vacuum arcs have to be mitigated through conditioning, during which an accelerating structure’s resilience against breakdowns is slowly increased through repeated radio frequency pulsing. Conditioning is very time and resource consuming, which is why developing more efficient procedures is desirable. At CERN, conditioning related research is conducted at the CLIC high-power X-band test stands. Breakdown localization is an important diagnostic tool of accelerating structure tests. Abnormal position distributions highlight issues in structure design, manufacturing or operation and may consequently help improve these processes. Additionally, positioning can provide insight into the physics of vacuum arcs. In this work, two established positioning methods based on the time-difference-ofarrival of radio frequency waves are extended. The first method i...

LHC and CLIC LLRF final reports

CERN Document Server

Dexter, A; Woolley, B; Ambattu, P; Tahir, I; Syratchev, Igor; Wuensch, Walter

2013-01-01

Crab cavities rotate bunches from opposing beams to achieve effective head-on collision in CLIC or collisions at an adjustable angle in LHC. Without crab cavities 90% of achievable luminosity at CLIC would be lost. In the LHC, the crab cavities allow the same or larger integrated luminosity while reducing significantly the requested dynamic range of physics detectors. The focus for CLIC is accurate phase synchronisation of the cavities, adequate damping of wakefields and modest amplitude stability. For the LHC, the main LLRF issues are related to imperfections: beam offsets in cavities, RF noise, measurement noise in feedback loops, failure modes and mitigations. This report develops issues associated with synchronising the CLIC cavities. It defines an RF system and experiments to validate the approach. It reports on the development of hardware for measuring the phase performance of the RF distributions system and cavities. For the LHC, the hardware being very close to the existing LLRF, the report focuses on...

Study of the supporting system for the CLIC Two-Beam Module

CERN Document Server

Gazis, Nick; Mainaud-Durand, Hélène; Gudkov, Dmitry; Samoshkin, Alexandre; Simopoulos, Simos; Hinis, Evangelos; Alexopoulos, Theodoros

2010-01-01

The Compact Linear Collider (CLIC) study aims at the development of a Multi-TeV e+ e-collider. The micro-precision CLIC structures will have an accelerating gradient of 100 MV/m and will be aligned on so-called girders. The girder construction constrains are mainly dictated by the beam physics and RF requirements. The study of such girders is a challenging case involving material choice, mechanical design as well as prototype fabrication and experimental testing.

CLIC: Physics potential of a high-energy e+e- collider

CERN Multimedia

CERN. Geneva

2018-01-01

The Compact Linear Collider (CLIC) is a future electron-positron collider under study. It foresees e+e- collisions at centre-of-mass energies ranging from a few hundred GeV up to 3 TeV. The CLIC study is an international collaboration hosted by CERN. The lectures provide a broad overview of the CLIC project, covering the physics potential, the particle detectors and the accelerator. An overview of the CLIC physics opportunities is presented. These are best exploited in a staged construction and operation scenario of the collider. The detector technologies, fulfilling CLIC performance requirements and currently under study, are described. The accelerator design and performance, together with its major technologies, are presented in the light of ongoing component tests and large system tests. The status of the optimisation studies (e.g. for cost and power) of the CLIC complex for the proposed energy staging is included. One lecture is dedicated to the use of CLIC technologies in free electron lasers and other ...

Study and application of micrometric alignment on the prototype girders of the CLIC Two-Beam Module

CERN Document Server

Gazis, Nikolaos; Mainaud-Durand, Hélène; Samochkine, Alexandre; Anastasopoulos, Michail

2011-01-01

The Compact LInear Collider (CLIC), currently under study at CERN, aims at the development of a Multi-TeV e+ e- collider. The micro-precision CLIC RF-structures will have an accelerating gradient of 100 MV/m and will be mounted and aligned on specially developed supporting girders. The girder fabrication constraints are dictated by stringent physics requirements. The micrometric pre-alignment over several kilometers of girders, allow for the CLIC structures to fulfill their acceleration and collision functionality. Study of such girders and their sophisticated alignment method, is a challenging case involving dedicated mechanical design as well as prototype production and experimental testing.

Physics at CLIC

CERN Document Server

AUTHOR|(SzGeCERN)669060; Roloff, Philipp Gerhard

2015-01-01

CLIC is a concept for a future linear collider which would use two-beam acceleration to produce e+e- collisions with a centre-of-mass energy of 3 TeV. A staging scenario would also provide collisions at lower centre-of-mass energies, provisionally 350 GeV and 1.4 TeV. In order to demonstrate the wide range of physics processes available at such a linear collider, and to benchmark the performance of proposed detector models, a campaign of simulated physics analyses including Higgs, top and beyond the Standard Model processes has been undertaken at these three energy stages. These proceedings present the current status of these studies and illustrate the potential for precision physics measurements at CLIC.

CLIC e+e- Linear Collider Studies

CERN Document Server

Dannheim, Dominik; Linssen, Lucie; Schulte, Daniel; Simon, Frank; Stapnes, Steinar; Toge, Nobukazu; Weerts, Harry; Wells, James

2012-01-01

This document provides input from the CLIC e+e- linear collider studies to the update process of the European Strategy for Particle Physics. It is submitted on behalf of the CLIC/CTF3 collaboration and the CLIC physics and detector study. It describes the exploration of fundamental questions in particle physics at the energy frontier with a future TeV-scale e+e- linear collider based on the Compact Linear Collider (CLIC) two-beam acceleration technique. A high-luminosity high-energy e+e- collider allows for the exploration of Standard Model physics, such as precise measurements of the Higgs, top and gauge sectors, as well as for a multitude of searches for New Physics, either through direct discovery or indirectly, via high-precision observables. Given the current state of knowledge, following the observation of a \\sim125 GeV Higgs-like particle at the LHC, and pending further LHC results at 8 TeV and 14 TeV, a linear e+e- collider built and operated in centre-of-mass energy stages from a few-hundred GeV up t...

CLIC preparations go up a notch

CERN Multimedia

2007-01-01

The Compact Linear Collider gears up for post-LHC physics with an international workshop. A schematic diagram of CLIC.In June CERN gained a new building: number 2010. And as chance would have it, this is more than just a number to its new residents. By the year 2010, teams working at the new CLIC Experimental Area, along with the already established CLIC Test Facility Three (CTF3), hope to have demonstrated the feasibility of the Compact Linear Collider and, depending on results from the LHC, embark on its final design and proposal. A workshop on 16t-18 October brought people from all around the world to CERN to exchange ideas and hear how the ambitious project is progressing. CLIC is a project that aims to extend lepton collider technology to multi-TeV energy physics, colliding leptons with a centre-of-mass-energy up to 3TeV, more than ten times the energy of the LEP. This is only possible in a linear collider, where no energy is lo...

Cherenkov Fibers for Beam Loss Monitoring at the CLIC Two Beam Module

CERN Document Server

van Hoorne, Jacobus Willem; Holzer, E B

The Compact Linear Collider (CLIC) study is a feasibility study aiming at a nominal center of mass energy of 3TeV and is based on normal conducting travelling-wave accelerating structures, operating at very high field gradients of 100 MV/m. Such high fields require high peak power and hence a novel power source, the CLIC two beam system, has been developed, in which a high intensity, low energy drive beam (DB) supplies energy to a high energy, low intensity main beam (MB). At the Two Beam Modules (TBM), which compose the 2x21km long CLIC main linac, a protection against beam losses resulting from badly controlled beams is necessary and particularly challenging, since the beam power of both main beam (14 MW) and drive beam (70 MW) is impressive. To avoid operational downtimes and severe damages to machine components, a general Machine Protection System (MPS) scheme has been developed. The Beam Loss Monitoring (BLM) system is a key element of the CLIC machine protection system. Its main role will be to detect p...

Test of the beam effect on vacuum arc occurrence in a high-gradient accelerating structure for the CLIC project

CERN Document Server

AUTHOR|(CDS)2130409; Gagliardi, Martino

A new generation of lepton colliders capable of reaching TeV energies is pres- ently under development, and to succeed in this task it is necessary to show that the technology for such a machine is available. The Compact Linear Collider (CLIC) is a possible design option among the future lepton collider projects. It consists of two normal-conducting linacs. Accelerating structures with a gradient of the order of 100 MV/m are necessary to reach the required high energies within a reasonable machine length. One of the strictest require- ments for such accelerating structures is a relatively low occurrence of vacuum arcs. CLIC prototype structures have been tested in the past, but only in absence of beam. In order to proof the feasibility of the high gradient technology for building a functional collider, it is necessary to understand the effect of the beam presence on the vacuum breakdowns. Tests of this type have never been performed previously. The main goal of this work is to provide a first measurement of t...

Feasibility Study for the CERN "CLIC" Photo-Injector Laser System

CERN Document Server

Ross, I N

2000-01-01

This study is designed to contribute to the development of the Cern Linear Collider (CLIC). One route to the generation of the required electron injection into this system is through the use of photo-cathodes illuminated with a suitably designed laser system. The requirements of the accelerator and photo-cathodes have led to a specification for the laser system given in Table 1. Because CLIC will not be built directly but in stages, notably via CLIC Test Facilities (CTF), this table also includes the specification for a photo-injector laser system for CTF3 which will be required before the final system for CLIC. Although there are significant differences between these two specifications it will be necessary to design the CTF3 system such that it can be easily upgraded to the system for CLIC and will be able to check all the critical issues necessary for CLIC.

RF Design of the TW Buncher for the CLIC Drive Beam Injector (2nd report)

CERN Document Server

Shaker, Hamed

2016-01-01

CLIC is based on the two beams concept that one beam (drive beam) produces the required RF power to accelerate another beam (main beam). The drive beam is produced and accelerated up to 50MeV inside the CLIC drive beam injector. The drive beam injector main components are a thermionic electron gun, three sub-harmonic bunchers, a pre-buncher, a TW buncher, 13 accelerating structures and one magnetic chicane. This document is the second report of the RF structure design of the TW buncher. This design is based on the beam dynamic design done by Shahin Sanaye Hajari due to requirements mentioned in CLIC CDR. A disk-loaded tapered structure is chosen for the TW buncher. The axial electric field increases strongly based on the beam dynamic requirements. This second report includes the study of HOM effects, retuning the cells, study of dimensional tolerances and the heat dissipation on the surface.

Simulation of Beam-Beam Background at CLIC

CERN Document Server

Sailer, Andre

2010-01-01

The dense beams used at CLIC to achieve a high luminosity will cause a large amount of background particles through beam-beam interactions. Generator level studies with GuineaPig and full detector simulation studies with an ILD based CLIC detector have been performed to evaluate the amount of beam-beam background hitting the vertex detector.

Simulation of Beam-Beam Background at CLIC

CERN Document Server

Sailer, A

2010-01-01

The dense beams used at CLIC to achieve a high luminosity will cause a large amount of background particles through beam-beam interactions. Generator level studies with GUINEAPIG and full detector simulation studies with an ILD based CLIC detector have been performed to evaluate the amount of beam-beam back- ground hitting the vertex detector.

WAKEFIELD DAMPING FOR THE CLIC CRAB CAVITY

CERN Document Server

Ambattu, P; Dexter, A; Carter, R; Khan, V; Jones, R; Dolgashev, V

2009-01-01

A crab cavity is required in the CLIC to allow effective head-on collision of bunches at the IP. A high operating frequency is preferred as the deflection voltage required for a given rotation angle and the RF phase tolerance for a crab cavity are inversely proportional to the operating frequency. The short bunch spacing of the CLIC scheme and the high sensitivity of the crab cavity to dipole kicks demand very high damping of the inter-bunch wakes, the major contributor to the luminosity loss of colliding bunches. This paper investigates the nature of the wakefields in the CLIC crab cavity and the possibility of using various damping schemes to suppress them effectively.

Achievements and Future Plans of CLIC Test Facilities

CERN Document Server

Braun, Hans Heinrich

2001-01-01

CTF2 was originally designed to demonstrate the feasibility of two-beam acceleration with high current drive beams and a string of 30 GHz CLIC accelerating structure prototypes (CAS). This goal was achieved in 1999 and the facility has since been modified to focus on high gradient testing of CAS's and 30 GHz single cell cavities (SCC). With these modifications, it is now possible to provide 30 GHz RF pulses of more than 150 MW and an adjustable pulselength from 3 to 15 ns. While the SCC results are promising, the testing of CAS's revealed problems of RF breakdown and related surface damage. As a consequence, a new R&D program has been launched to advance the understanding of RF breakdown processes, to improve surface properties, investigate new materials and to optimise the structure geometries of the CAS's. In parallel the construction of a new facility named CTF3 has started. CTF3 will mainly serve two purposes. The first is the demonstration of the CLIC drive beam generation scheme. CTF3 will acceler-a...

TCAD simulations of High-Voltage-CMOS Pixel structures for the CLIC vertex detector

CERN Document Server

Buckland, Matthew Daniel

2016-01-01

The requirements for precision physics and the experimental conditions at CLIC result in stringent constraints for the vertex detector. Capacitively coupled active pixel sensors with 25 μm pitch implemented in a commercial 180 nm High-Voltage CMOS (HV-CMOS) process are currently under study as a candidate technology for the CLIC vertex detector. Laboratory calibration measurements and beam tests with prototypes are complemented by detailed TCAD and electronic circuit simulations, aiming for a comprehensive understanding of the signal formation in the HV-CMOS sensors and subsequent readout stages. In this note 2D and 3D TCAD simulation results of the prototype sensor, the Capacitively Coupled Pixel Detector version three (CCPDv3), will be presented. These include the electric field distribution, leakage current, well capacitance, transient response to minimum ionising particles and charge-collection.

Light-flavor squark reconstruction at CLIC

CERN Document Server

AUTHOR|(SzGeCERN)548062; Weuste, Lars

2015-01-01

We present a simulation study of the prospects for the mass measurement of TeV-scale light- flavored right-handed squark at a 3 TeV e+e collider based on CLIC technology. The analysis is based on full GEANT4 simulations of the CLIC_ILD detector concept, including Standard Model physics backgrounds and beam-induced hadronic backgrounds from two- photon processes. The analysis serves as a generic benchmark for the reconstruction of highly energetic jets in events with substantial missing energy. Several jet finding algorithms were evaluated, with the longitudinally invariant kt algorithm showing a high degree of robustness towards beam-induced background while preserving the features typically found in algorithms developed for e+e- collisions. The presented study of the reconstruction of light-flavored squarks shows that for TeV-scale squark masses, sub-percent accuracy on the mass measurement can be achieved at CLIC.

A Versatile Beam Loss Monitoring System for CLIC

CERN Document Server

Kastriotou, Maria; Farabolini, Wilfrid; Holzer, Eva Barbara; Nebot Del Busto, Eduardo; Tecker, Frank; Welsch, Carsten

2016-01-01

The design of a potential CLIC beam loss monitoring (BLM) system presents multiple challenges. To successfully cover the 48 km of beamline, ionisation chambers and optical fibre BLMs are under investigation. The former fulfils all CLIC requirements but would need more than 40000 monitors to protect the whole facility. For the latter, the capability of reconstructing the original loss position with a multi-bunch beam pulse and multiple loss locations still needs to be quantified. Two main sources of background for beam loss measurements are identified for CLIC. The two-beam accelerator scheme introduces so-called crosstalk, i.e. detection of losses originating in one beam line by the monitors protecting the other. Moreover, electrons emitted from the inner surface of RF cavities and boosted by the high RF gradients may produce signals in neighbouring BLMs, limiting their ability to detect real beam losses. This contribution presents the results of dedicated experiments performed in the CLIC Test Facility to qu...

M10.3.4: CLIC crab cavity specifications completed

CERN Document Server

Dexter, A; Ambattu, P; Shinton, I; Jones, R

2010-01-01

The starting point of Sub-task 2 is to document the currently anticipated requirements for the CLIC crab cavity system. This milestone concerns completion of the basic specifications for the CLIC crab cavity system. This comprises kick, power requirement, phase and amplitude stability, technology choice, and RF layout. The wakefield calculations of a baseline CLIC cavity will be used to estimate the required damping of the higher order modes as well as other special modes in crab cavities (the lower and same order modes).

CLIC CRAB CAVITY SPECIFICATIONS MILESTONE: M10.3.4

CERN Document Server

Ambattu, P; Dexter, A; Jones, R; McIntosh, P; Shinton, I

2010-01-01

The starting point of Sub-task 2 is to document the currently anticipated requirements for the CLIC crab cavity system. This milestone concerns completion of the basic specifications for the CLIC crab cavity system. This comprises kick, power requirement, phase and amplitude stability, technology choice, and RF layout. The wakefield calculations of a baseline CLIC cavity will be used to estimate the required damping of the higher order modes as well as other special modes in crab cavities (the lower and same order modes).

Vertex-Detector R&D for CLIC

OpenAIRE

Dannheim, Dominik

2013-01-01

A detector concept based on hybrid planar pixel-detector technology is under development for the CLIC vertex detector. It comprises fast, low-power and small-pitch readout ASICs implemented in 65 nm CMOS technology (CLICpix) coupled to ultra-thin sensors via low-mass interconnects. The power dissipation of the readout chips is reduced by means of power pulsing, allowing for a cooling system based on forced gas flow. In this paper the CLIC vertex-detector requirements are reviewed and the curr...

Accelerator Physics for ILC and CLIC

CERN Document Server

Zimmermann, F

2010-01-01

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

CLICdet: The post-CDR CLIC detector model

CERN Document Server

Alipour Tehrani, Niloufar; Cure, Benoit; Dannheim, Dominik; Duarte Ramos, Fernando; Elsener, Konrad; Gaddi, Andrea; Gerwig, Hubert; Green, Steven; Grefe, Christian; Hynds, Daniel; Klempt, Wolfgang; Linssen, Lucie; Nikiforou, Nikiforos; Nurnberg, Andreas Matthias; Marshall, John Stuart; Petric, Marko; Redford, Sophie; Roloff, Philipp Gerhard; Sailer, Andre; Sefkow, Felix; Sicking, Eva; Siegrist, Nicolas; Simon, Frank Richard; Simoniello, Rosa; Spannagel, Simon; Sroka, Szymon Krzysztof; Strom, Lars Rickard; Weber, Matthias Artur

2017-01-01

A new model for the CLIC detector has been defined based on lessons learnt while working with the CDR detector models and after a series of simulation studies. The new model, dubbed "CLICdet", also incorporates the experience from various R&D activities linked to a future experiment at CLIC. This note describes the studies and thoughts leading to the new detector model, and gives details on all of its sub-detector systems.

The physics benchmark processes for the detector performance studies used in CLIC CDR Volume 3

CERN Document Server

Allanach, B.J.; Desch, K.; Ellis, J.; Giudice, G.; Grefe, C.; Kraml, S.; Lastovicka, T.; Linssen, L.; Marschall, J.; Martin, S.P.; Muennich, A.; Poss, S.; Roloff, P.; Simon, F.; Strube, J.; Thomson, M.; Wells, J.D.

2012-01-01

This note describes the detector benchmark processes used in volume 3 of the CLIC conceptual design report (CDR), which explores a staged construction and operation of the CLIC accelerator. The goal of the detector benchmark studies is to assess the performance of the CLIC ILD and CLIC SiD detector concepts for different physics processes and at a few CLIC centre-of-mass energies.

Simulation and Optimisation of CLIC's recombination complex

CERN Document Server

Costa, Raul; Barroso, Manuel

In this thesis we present the first Placet2 recombination simulations of the drive beam recombination complex (DBRC) design for the compact linear collider (CLIC). We start by presenting a review of the CLIC project and the DBRC’s role and design within it. We then discuss some of the core principles of beam dynamics and how tracking codes like Placet2 implement them. We follow that by presenting the design issues raised by our simulations and our proposed strategy to address them, key among which is a previously unknown parabolic dependency of the longitudinal position to the momentum (T 566 ), which threat- ens the efficiency of the power extraction structures. Through iterative opti- misation of the design, we eliminated this aberration both in the delay loop and in combiner ring 1. We also found the beam’s horizontal emittance to be significantly over the design budget (150 μm) and attempted to meet that budget, reaching 157 μm. In order to obtain this emittance value, an update to the combiner ring...

Status of Ground Motion Mitigation Techniques for CLIC

CERN Document Server

Snuverink, J; Collette, C; Duarte Ramos, F; Gaddi, A; Gerwig, H; Janssens, S; Pfingstner, J; Schulte, D; Balik, G; Brunetti, L; Jeremie, A; Burrows, P; Caron, B; Resta-Lopez, J

2011-01-01

The Compact Linear Collider (CLIC) accelerator has strong stability requirements on the position of the beam. In particular, the beam position will be sensitive to ground motion. A number of mitigation techniques are proposed - quadrupole stabilisation and positioning, final doublet stabilisation as well as beam based orbit and interaction point (IP) feedback. Integrated studies of the impact of the ground motion on the CLIC Main Linac (ML) and Beam Delivery System (BDS) have been performed, which model the hardware and beam performance in detail. Based on the results future improvements of the mitigation techniques are suggested and simulated. It is shown that with the current design the tight luminosity budget for ground motion effects is fulfilled and accordingly, an essential feasibility issue of CLIC has been addressed.

CLIC project timeline

CERN Multimedia

CLIC, Compact Linear Collider Project

2018-01-01

The CLIC project timeline. Current plan is to start at sqrt(s)=380 GeV for Higgs and top quark precision physics and upgrade up to 3 TeV. This timeline represent a purely technical schedule and assumes support at the European Strategy for Particle Physics (ESPP) in 2020 and available funding.

CLIC: Overview of applications using high-gradient acceleration, from photon sources to medical physics

CERN Multimedia

CERN. Geneva

2018-01-01

The Compact Linear Collider (CLIC) is a future electron-positron collider under study. It foresees e+e- collisions at centre-of-mass energies ranging from a few hundred GeV up to 3 TeV. The CLIC study is an international collaboration hosted by CERN. The lectures provide a broad overview of the CLIC project, covering the physics potential, the particle detectors and the accelerator. An overview of the CLIC physics opportunities is presented. These are best exploited in a staged construction and operation scenario of the collider. The detector technologies, fulfilling CLIC performance requirements and currently under study, are described. The accelerator design and performance, together with its major technologies, are presented in the light of ongoing component tests and large system tests. The status of the optimisation studies (e.g. for cost and power) of the CLIC complex for the proposed energy staging is included. One lecture is dedicated to the use of CLIC technologies in free electron lasers and other ...

Physics highlights at ILC and CLIC

CERN Document Server

Lukić, Strahinja

2015-01-01

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

Technical Specification for the CLIC Two-Beam Module

CERN Document Server

Riddone, G; Nousiainen, R; Samoshkin, A; Schulte, D; Syratchev, I; Wuensch, W; Zennaro, R

2008-01-01

A high-energy (0.5-3 TeV centre-of-mass), highluminosity Compact Linear Collider (CLIC) is being studied at CERN [1]. The CLIC main linacs, 21-km long each, are composed of 2-m long two beam modules. This paper presents their current layout, the main requirements for the different sub-systems (alignment, supporting, stabilization, cooling and vacuum) as well as the status of their integration.

CLIC project R&D studies: the magnet system for the 3 TEV

CERN Document Server

Modena, Michele

2017-01-01

This Note presents the R&D activities done and coordinated by TE-MSC Group on the magnetic system for the CLIC (Compact Linear Collider) project. The main aspects investigated are: the magnetic system definition, basic design for all magnets (i.e. a CLIC Magnet Catalogue), powering and cost evaluation, advanced design and prototyping for the most critical magnet variants. The CLIC layout here considered is the one for the highest collision energy of 3 TeV. This layout was the one studied in detail as baseline for the CLIC Conceptual Design Report that was released in 2012. This Note summarize the activities of about 6 years (2010-2016) done with the contribution of CERN staff (part-time), the contribution of some CERN Project Associates sponsored by the CLIC Project and in collaboration with STCF Daresbury Laboratory (UK).

Status of vertex and tracking detector R&D at CLIC

CERN Document Server

AUTHOR|(SzGeCERN)754272

2015-01-01

The physics aims at the future CLIC high-energy linear e+e- collider set very high precision requirements on the performance of the vertex and tracking detectors. Moreover, these detectors have to be well adapted to the experimental conditions, such as the bunch train structure of the beam and the presence of beam-induced backgrounds. The principal challenges are: a point resolution of a few micron, ultra-low mass (~0.2% X0 per layer for the inner vertex region), very low power dissipation (compatible with air-flow cooling in the inner vertex region) and pulsed power operation, complemented with ~10 ns time stamping capabilities. An overview of the R&D program for pixel and tracking detectors at CLIC will be presented, including recent results on an innovative hybridisation concept based on capacitive coupling between active sensors (HV-CMOS) and readout ASICs (CLICpix).

The CLIC programme: Towards a staged $e^{+}e^{−}$ linear collider exploring the terascale CLIC conceptual design report

CERN Document Server

Lebrun, P.; Lucaci-Timoce, A.; Schulte, D.; Simon, F.; Stapnes, S.; Toge, N.; Weerts, H.; Wells, J.

2012-01-01

This report describes the exploration of fundamental questions in particle physics at the energy frontier with a future TeV-scale $e^+e^-$ linear collider based on the Compact Linear Collider (CLIC) two-beam acceleration technology. A high-luminosity high-energy $e^+e^-$ collider allows for the exploration of Standard Model physics, such as precise measurements of the Higgs, top and gauge sectors, as well as for a multitude of searches for New Physics, either through direct discovery or indirectly, via high-precision observables. Given the current state of knowledge, following the observation of a 125 GeV Higgs-like particle at the LHC, and pending further LHC results at 8 TeV and 14 TeV, a linear $e^+e^-$ collider built and operated in centre-of-mass energy stages from a few-hundred GeV up to a few TeV will be an ideal physics exploration tool, complementing the LHC. In this document, an overview of the physics potential of CLIC is given. Two example scenarios are presented for a CLIC accelerator built in th...

Validation of CLIC Re-Adjustment System Based on Eccentric Cam Movers One Degree of Freedom Mock-Up

CERN Document Server

Kemppinen, J; Lackner, F

2011-01-01

Compact Linear Collider (CLIC) is a 48 km long linear accelerator currently studied at CERN. It is a high luminosity electron-positron collider with an energy range of 0.5-3 TeV. CLIC is based on a two-beam technology in which a high current drive beam transfers RF power to the main beam accelerating structures. The main beam is steered with quadrupole magnets. To reach CLIC target luminosity, the main beam quadrupoles have to be actively pre-aligned within 17 µm in 5 degrees of freedom and actively stabilised at 1 nm in vertical above 1 Hz. To reach the pre-alignment requirement as well as the rigidity required by nano-stabilisation, a system based on eccentric cam movers is proposed for the re-adjustment of the main beam quadrupoles. Validation of the technique to the stringent CLIC requirements was started with tests in one degree of freedom on an eccentric cam mover. This paper describes the dedicated mock-up as well as the tests and measurements carried out with it. Finally, the test results are present...

First phase of CLIC R&D complete

CERN Multimedia

Katarina Anthony

2012-01-01

Let’s turn back the clocks to 2002: the LHC is still under construction, the wrap-up of the LEP physics programme is still in recent memory and the future of electron-positron accelerators at CERN is ambiguous. It was then that CLIC set out to prove the feasibility of their novel accelerator design in the CTF3 test facility. Though once a tall order for the collaboration, the recently released CLIC Conceptual Design Report has proven many of the major design elements… bringing to an end the first phase of CLIC R&D and pointing toward detailed performance optimisation studies in the next phase.   Streak camera images of the final beam, illustrating the combination of beams in the Combiner Ring. Over a decade ago, the CTF3 team set up shop in the vacated LIL injector site, once home to the weathered machine that delivered electrons and positrons to LEP. Rebuilding and upgrading the machine piece by piece, the CTF3 team converted this mA linac into a high-current drive b...

Silicon Technologies for the CLIC Vertex Detector

CERN Document Server

Spannagel, Simon

2017-01-01

CLIC is a proposed linear e$^+$e$^−$ collider designed to provide particle collisions at center-of-mass energies of up to 3 TeV. Precise measurements of the properties of the top quark and the Higgs boson, as well as searches for Beyond the Standard Model physics require a highly performant CLIC detector. In particular the vertex detector must provide a single point resolution of only a few micrometers while not exceeding the envisaged material budget of around 0.2%$~X_0$ per layer. Beam-beam interactions and beamstrahlung processes impose an additional requirement on the timestamping capabilities of the vertex detector of about 10 ns. These goals can only be met by using novel techniques in the sensor and ASIC design as well as in the detector construction. The R&D program for the CLIC vertex detector explores various technologies in order to meet these demands. The feasibility of planar sensors with a thickness of 50–150$~\\mu$m, including different active edge designs, are evaluated using Timepix3 A...

Thermo-Mechanical tests for the CLIC two-beam module study

CERN Document Server

Xydou, A; Riddone, G; Daskalaki, E

2014-01-01

The luminosity goal of CLIC requires micron level precision with respect to the alignment of the components on its two-meter long modules, composing the two main linacs. The power dissipated inside the module components introduces mechanical deformations affecting their alignment and therefore the resulting machine performance. Several two-beam prototype modules must be assembled to extensively measure their thermo-mechanical behavior under different operation modes. In parallel, the real environmental conditions present in the CLIC tunnel should be studied. The air conditioning and ventilation system providing specified air temperature and flow has been installed in the dedicated laboratory. The power dissipation occurring in the modules is being reproduced by the electrical heaters inserted inside the RF structure mock-ups and the quadrupoles. The efficiency of the cooling systems is being verified and the alignment of module components is monitored. The measurement results will be compared to finite elemen...

Pulse Power Modulator development for the CLIC Damping Ring Kickers

CERN Document Server

Holma, Janne

2012-01-01

The Compact Linear Collider (CLIC) study is exploring the scheme for an electron-positron collider with high luminosity (10-34 – 10-35 cm-2s-1) and a nominal centre-of-mass energy of 3 TeV: CLIC would complement LHC physics in the multi-TeV range. The CLIC design relies on Pre-Damping Rings (PDR) and Damping Rings (DR) to achieve the very low emittance, through synchrotron radiation, needed for the luminosity requirements of CLIC. To limit the beam emittance blow-up due to oscillations, the pulse power modulators for the DR kickers must provide extremely flat, high-voltage pulses: the 2 GHz specification called for a 160 ns duration flat-top of 12.5 kV, 250 A, with a combined ripple and droop of not more than ±0.02 %. In order to meet these demanding specifications, a combination of broadband impedance matching, optimized electrical circuit layout and advanced control techniques is required. A solid-state modulator, the inductive adder, is the most promising approach to meeting the demanding specifications...

CLIC/ILC Researchers Explore New Avenues for Collaboration

CERN Multimedia

Katarina Anthony

2010-01-01

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

Propagation error simulations concerning the CLIC active prealignment

CERN Document Server

Touzé, T; Missiaen, D

2009-01-01

The CLIC1 components will have to be prealigned within a thirty times more demanding tolerance than the existing CERNmachines. It is a technical challenge and a key issue for the CLIC feasibility. Simulations have been undertaken concerning the propagation error due to the measurement uncertainties of the prealignment systems. The uncertainties of measurement, taken as hypothesis for the simulations, are based on the data obtained on several dedicated facilities. This paper introduces the simulations and the latest results obtained, as well as the facilities.

CLIC's three-step plan

CERN Multimedia

Katarina Anthony

2012-01-01

In early October, the Compact Linear Collider (CLIC) collaboration published its final Conceptual Design Report. Accompanying it was a strategic summary document that describes a whole new approach to the project: developing the linear e+e− collider in three energy stages. Though CLIC’s future still depends on signs from the LHC, its new staged approach to high-energy electron-positron physics for the post-LHC era is nothing short of convincing.   Instead of asking for a 48-kilometre-long commitment right off the bat, the CLIC collaboration is now presenting an accelerator that can be constructed in stages. For example, it could begin as an 11-kilometre 500 GeV accelerator that could later be extended to a 27-kilometre 1.5 TeV machine. Finally, after a decade or so of data taking, it could be taken up to the full 48-kilometre 3 TeV facility (see image 2). “Not only is the approach technically and financially practical, it also offers a very convincing physics prog...

R and D for the Feasibility Study of CLIC Technology

CERN Document Server

Braun, H; Geschonke, Günther; Guignard, Gilbert; Hübner, K; Wilson, Ian H

2004-01-01

An overview is given of the necessary R&D and particularly of the CLIC test facility CTF3 which is presently under construction for demonstrating the key issues related to the CLIC technology and to the two-beam scheme. The results concerning the commissioning of the injector and of the first part of the linac already built are summarized. The main R&D topics to be covered with this test infrastructure are described and the planned road-map in order to reach the pre-defined goals is indicated. The potential of CTF3 for checking the bunch-train recombination, testing RF accelerating structures, investigating the use of a drive-beam for RF power production, for bench-marking simulation codes and possibly making low-energy experiments related to linear collider R&D is presented. The activities required for the feasibility programme planned are given in the form of work packages, together with the needed but not available resources and the time schedule.

Simulation of an all silicon tracker for CLIC

Energy Technology Data Exchange (ETDEWEB)

Muenker, Magdalena; Nuernerg, Andreas [CERN (Switzerland); University of Bonn (Germany)

2016-07-01

CLIC is a proposed future electron-positron linear collider with a centre-of-mass energy up to 3 TeV. The aim of high precision measurements at CLIC is driving the design of the detector for CLIC. To perform a precise measurement of the Higgs recoil mass a momentum resolution of σ{sub p{sub T}}/p{sub T}{sup 2} ∝2 . 10{sup -5} GeV{sup -1} is required. This imposes a single point tracking resolution of ∝7 μm. To reach this aim an all silicon tracker is foreseen for CLIC. A simulation chain has been set up to study the performance of different silicon sensor designs. This simulation chain consists of a GEANT4 simulation to model the energy deposit in silicon, a finite element simulation of the charge drift and signal formation with TCAD and a fast parametric modelling of the front-end electronics. By that energy fluctuations, electronic noise and the digitalisation of the readout signal are taken into account. Furthermore this tool is used to predict the sensor performance in terms of efficiency, cluster-size and resolution. This framework is used to study the performance of e.g. sensors with different pitch and thickness. Various incident angles of charged particles with respect to the sensor surface and the effect of a magnetic field are taken into account. The simulation chain is validated with data.

ISSUES AND FEASIBILITY DEMONSTRATION OF CLIC SUPPORTING SYSTEM CHAIN ACTIVE PRE-ALIGNMENT USING A MULTI-MODULE TEST SETUP (MOCK-UP)

CERN Document Server

Sosin, Mateusz

2016-01-01

The implementation study of the CLIC (Compact LInear Collider) is under way at CERN with a focus on the challenging issues. The pre-alignment precision and accuracy requirements are part of these technical challenges: the permissible transverse position errors of the linac components are typically 14 micrometers over sliding windows of 200m. To validate the proposed methods and strategies, the Large Scale Metrology section at CERN has performed campaigns of measurements on the CLIC Two Beam Test Modules, focusing inter alia on the alignment performance of the CLIC “snake”- girders configuration and the Main Beam Quadrupoles supporting structures. This paper describes the activities and results of tests which were performed on the test mock-up for the qualification of the CLIC supporting system chain for active pre-alignment. The lessons learnt (“know how”), the issues encountered in the girder position determination as well as the behaviour of the mechanical components are presented.

Online Resources for High School Teachers--A CLIC Away

Science.gov (United States)

Holmes, Jon L.

2000-04-01

"I'm a high school teacher. I don't have time to sift through all of JCE to find what I need. I don't have enough time as it is!" If you need to find things in a hurry, go to JCE HS CLIC, the JCE High School Chemed Learning Information Center, http://JChemEd.chem.wisc.edu/HS/. You will find good solid, reliable information, and you will find it fast. CLIC is open 24 hours every day, all over the world. What You Will Find at JCE CLIC We know teachers are pressed for time. During the few minutes between classes or at the end of the day, information needs to be found very quickly. Perhaps you are looking for a demo that illustrates electrochemistry using Cu, Mg, orange juice, and a clock; or a student activity on chromatography that is ready to copy and hand out; or a video to illustrate the action of aqua regia on gold, because you can't use aqua regia and can't afford gold. You can find each of these quickly at CLIC. The Journal has always provided lots of articles designed with high school teachers in mind. What the new JCE HS CLIC does is collect the recent materials at one address on JCE Online, making it quicker and easier for you to find them. Information has been gathered from both print and online versions of the Journal, from JCE Software, and from JCE Internet. It is organized as shown at the bottom of the page. Getting Access to Information You have located something that interests you, perhaps a list of tested demonstrations that pertain to consumer chemistry. Now it is time to get it. JCE subscribers (individuals and libraries) can read, download, and print the full versions of the articles as well as all supplemental materials, including student handouts and instructor's notes. You will need the username and password that are on the mailing label that comes with your Journaleach month. JCE HS CLIC home page: http://JChemEd.chem.wisc.edu/HS/ Your Suggestions, Please Our plans for JCE HS CLIC do not end with what you find now. Other resources and features

Impact of Dynamic Magnetic fields on the CLIC Main Beam

CERN Document Server

Snuverink, J; Jach, C; Jeanneret, JB; Schulte, D; Stulle, F

2010-01-01

The Compact Linear Collider (CLIC) accelerator has strong precision requirements on the position of the beam. The beam position will be sensitive to external dynamic magnetic fields (stray fields) in the nanotesla regime. The impact of these fields on the CLIC main beam has been studied by performing simulations on the lattices and tolerances have been determined. Several mitigation techniques will be discussed.

Silicon pixel R&D for CLIC

CERN Document Server

AUTHOR|(SzGeCERN)718101

2017-01-01

The physics aims at the proposed future CLIC high-energy linear e+e− collider pose challenging demands on the performance of the vertex and tracking detector system. In particular the detectors have to be well adapted to the experimental conditions, such as the time structure of the collisions and the presence of beam-induced backgrounds. The requirements include ultra-low mass, facilitated by power pulsing and air cooling in the vertex-detector region, small cell sizes and precision hit timing at the few-ns level. A highly granular all- silicon vertex and tracking detector system is under development, following an integrated approach addressing simultaneously the physics requirements and engineering constraints.

Performance-Optimization Studies for the CLIC Vertex Detector

CERN Document Server

AUTHOR|(CDS)2085406; Roloff, Philipp

The Compact Linear Collider (CLIC) is a mutli-TeV linear e+e- collider currently under development at CERN. In the post-LHC era, CLIC will allow to explore a great number of searches for New Physics such as the precise measurements of the Higgs boson. In this master thesis, we mainly focus on the development and the improvement of the vertex detector. The vertex detector requires excellent spatial resolution, low mass, geometrical coverage down to low polar angles, high rate readout for the sensors and new cooling technologies for heat removal. Considering such requirements, the CLIC vertex detector technology is far more advanced in comparison to the technologies currently used in particle physics. This project consists of two main parts. In the first part, we study the vertex detector and optimize its geometry for the use of airflow cooling techniques and also for flavor tagging. In the second part, we implement a decoder which can respect the timing constraints for the CLICpix chip, a silicon pixel detect...

Detector optimization studies and light Higgs decay into muons at CLIC

Energy Technology Data Exchange (ETDEWEB)

Grefe, Christian

2013-09-15

The Compact Linear Collider (CLIC) is a concept for a future e{sup +}e{sup -} linear collider with a center-of-mass energy of up to 3 TeV. The design of a CLIC experiment is driven by the requirements related to the physics goals, as well as by the experimental conditions. For example, the short time between two bunch crossings of 0.5 ns and the backgrounds due to beamstrahlung have direct impact on the design of a CLIC experiment. The Silicon Detector (SiD) is one of the concepts currently being discussed as a possible detector for the International Linear Collider (ILC). In this thesis we develop a modified version of the SiD simulation model for CLIC, taking into account the specific experimental conditions. In addition, we developed a software tool to investigate the impact of beam-related backgrounds on the detector by overlaying events from different simulated event samples. Moreover, we present full simulation studies, determining the performance of the calorimeter and tracking systems. We show that the track reconstruction in the all-silicon tracker of SiD is robust in the presence of the backgrounds at CLIC. Furthermore, we investigate tungsten as a dense absorber material for the hadronic calorimeter, which allows for the construction of a compact hadronic calorimeter that fulfills the requirements on the energy resolution and shower containment without a significant increase of the coil radius. Finally, the measurement of the decays of light Higgs bosons into two muons is studied in full simulation. We find that with an integrated luminosity of 2 ab{sup -1}, corresponding to 4 years of data taking at CLIC, the respective Higgs branching ratio can be determined with a statistical uncertainty of approximately 15%.

Detector optimization studies and light Higgs decay into muons at CLIC

International Nuclear Information System (INIS)

Grefe, Christian

2013-09-01

The Compact Linear Collider (CLIC) is a concept for a future e + e - linear collider with a center-of-mass energy of up to 3 TeV. The design of a CLIC experiment is driven by the requirements related to the physics goals, as well as by the experimental conditions. For example, the short time between two bunch crossings of 0.5 ns and the backgrounds due to beamstrahlung have direct impact on the design of a CLIC experiment. The Silicon Detector (SiD) is one of the concepts currently being discussed as a possible detector for the International Linear Collider (ILC). In this thesis we develop a modified version of the SiD simulation model for CLIC, taking into account the specific experimental conditions. In addition, we developed a software tool to investigate the impact of beam-related backgrounds on the detector by overlaying events from different simulated event samples. Moreover, we present full simulation studies, determining the performance of the calorimeter and tracking systems. We show that the track reconstruction in the all-silicon tracker of SiD is robust in the presence of the backgrounds at CLIC. Furthermore, we investigate tungsten as a dense absorber material for the hadronic calorimeter, which allows for the construction of a compact hadronic calorimeter that fulfills the requirements on the energy resolution and shower containment without a significant increase of the coil radius. Finally, the measurement of the decays of light Higgs bosons into two muons is studied in full simulation. We find that with an integrated luminosity of 2 ab -1 , corresponding to 4 years of data taking at CLIC, the respective Higgs branching ratio can be determined with a statistical uncertainty of approximately 15%.

Occupancy in the CLIC ILD Time Projection Chamber using Pixelised Readout

CERN Document Server

Killenberg, Martin

2013-01-01

The occupancy in the CLIC ILD TPC caused by the beam induced background from gamma gamma -> hadrons, e+e- pairs and beam halo muons is very high for conventional pad readout. We show that the occupancy for a pixelised TPC readout is moderate and might be a viable solution to operate a TPC at CLIC.

Dimension-6 operator analysis of the CLIC sensitivity to new physics

International Nuclear Information System (INIS)

Ellis, John; Roloff, Philipp; Sanz, Verónica; You, Tevong

2017-01-01

We estimate the possible accuracies of measurements at the proposed CLIC e + e − collider of Higgs and W + W − production at centre-of-mass energies up to 3 TeV, incorporating also Higgsstrahlung projections at higher energies that had not been considered previously, and use them to explore the prospective CLIC sensitivities to decoupled new physics. We present the resulting constraints on the Wilson coefficients of dimension-6 operators in a model-independent approach based on the Standard Model effective field theory (SM EFT). The higher centre-of-mass energy of CLIC, compared to other projects such as the ILC and CEPC, gives it greater sensitivity to the coefficients of some of the operators we study. We find that CLIC Higgs measurements may be sensitive to new physics scales Λ=O(10) TeV for individual operators, reduced to O(1) TeV sensitivity for a global fit marginalising over the coefficients of all contributing operators. We give some examples of the corresponding prospective constraints on specific scenarios for physics beyond the SM, including stop quarks and the dilaton/radion.

Top Mass Measurement at CLIC at 500 GeV

CERN Document Server

Simon, Frank; Poss, Stephane

2012-01-01

We present a study of the capability of a 500 GeV e+e- collider based on CLIC technology for precision measurements of top quark properties. The analysis is based on full detector simulations of the CLIC_ILD detector concept using Geant4, including realistic background contributions from two photon processes. Event reconstruction is performed using a particle flow algorithm with stringent cuts to control the influence of background. The mass and width of the top quark are studied in fully-hadronic and semi-leptonic decays of ttbar pairs using event samples of signal and standard model background processes corresponding to an integrated luminosity of 100/fb. Statistical uncertainties of the top mass given by the invariant mass of its decay products of 0.08 GeV and 0.09 GeV are obtained for the fully-hadronic and the semi-leptonic decay channel, respectively, demonstrating that similar precision to that at ILC can be achieved at CLIC despite less favorable experimental conditions.

Drive beam stabilisation in the CLIC Test Facility 3

Science.gov (United States)

Malina, L.; Corsini, R.; Persson, T.; Skowroński, P. K.; Adli, E.

2018-06-01

The proposed Compact Linear Collider (CLIC) uses a high intensity, low energy drive beam to produce the RF power needed to accelerate a lower intensity main beam with 100 MV/m gradient. This scheme puts stringent requirements on drive beam stability in terms of phase, energy and current. The consequent experimental work was carried out in CLIC Test Facility CTF3. In this paper, we present a novel analysis technique in accelerator physics to find beam drifts and their sources in the vast amount of the continuously gathered signals. The instability sources are identified and adequately mitigated either by hardware improvements or by implementation and commissioning of various feedbacks, mostly beam-based. The resulting drive beam stability is of 0.2°@ 3 GHz in phase, 0.08% in relative beam energy and about 0.2% beam current. Finally, we propose a stabilisation concept for CLIC to guarantee the main beam stability.

Higgs Physics at CLIC

CERN Document Server

AUTHOR|(CDS)2073690

2016-01-01

The Compact Linear Collider (CLIC) is an attractive option for a future multi-TeV linear electron-positron collider, offering the potential for a rich precision physics programme, combined with sensitivity to a wide range of new phenomena. The physics reach of CLIC has been studied in the context of three distinct centre-of-mass energies, √s = 350 GeV, 1.4 TeV and 3.0 TeV. This staged scenario provides an excellent environment for precise studies of the properties of the 126 GeV Higgs boson. Operation at √s = 350 GeV allows, on the one hand, for a determination of the couplings and width of the Higgs boson in a model-independent manner through the study of the Higgsstrahlung process, and on the other hand, for a study of Higgs bosons produced in W+W− fusion for the most common Higgs decay modes. Operation at higher centre-of-mass energies, √s = 1.4 TeV and 3 TeV, provides high statistics W+W− fusion samples allowing for high precision measurements of many Higgs couplings and a study of rare Higgs de...

Vertex and Tracker Research and Development for CLIC

CERN Document Server

Munker, M

2017-01-01

Challenging detector requirements are imposed by the physics goals at the future multi-TeV e+e− Compact Linear Collider (CLIC). A single point resolution of 3 μm for the vertex detector and 7 μm for the tracker is required. Moreover, the CLIC vertex detector and tracker need to be extremely light weighted with a material budget of 0.2%X0 per layer in the vertex detector and 1 - 2%X0 in the tracker. A fast time slicing of 10 ns is further required to suppress background from beam-beam interactions. A wide range of sensor and readout ASIC technologies are investigated within the CLIC silicon pixel R&D; effort. Various hybrid planar sensor assemblies with a pixel size of 25 × 25 μm2 and 55 × 55 μm2 have been produced and characterised by laboratory measurements and during test-beam campaigns. Experimental and simulation results for thin (50 μm- 500 μm) slim edge and active-edge planar, and High-Voltage CMOS sensors hybridised to various readout ASICs (Timepix, Timepix3, CLICpix) are presented.

Study of the Thermo-Mechanical Behavior of the CLIC Two-Beam Modules

CERN Document Server

Rossi, F; Riddone, G; Österberg, K; Kossyvakis, I; Gudkov, D; Samochkine, A

2013-01-01

The final luminosity target of the Compact LInear Collider (CLIC) imposes a micron-level stability requirement on the two-meter repetitive two-beam modules constituting the main linacs. Two-beam prototype modules are being assembled to extensively study their thermo-mechanical behaviour under different operation modes. The power dissipation occurring in the modules will be reproduced and the efficiency of the corresponding cooling systems validated. At the same time, the real environmental conditions present in the CLIC tunnel will be studied. Air conditioning and ventilation systems have been installed in the dedicated laboratory. The air temperature will be changed from 20 to 40°C, while the air flow rate will be varied up to 0.8 m/s. During all experimental tests, the alignment of the RF structures will be monitored to investigate the influence of power dissipation and air temperature on the overall thermo-mechanical behaviour. \

CLIC Brochure

CERN Multimedia

AUTHOR|(CDS)2086185

2015-01-01

After the discovery of the Higgs boson and with upgrades to higher energy and luminosity, the LHC is mapping the route of particle physics into the future. The next step in this journey of discovery could be a linear electron-positron collider, which would complement the LHC and allow high precision measurements of the Higgs boson, the top quark and electroweak processes in addition to possible new physics beyond the Standard Model. The Compact Linear Collider is under development by two worldwide collaborations, pushing the limits of particle acceleration and detection. Technological R&D, physics simulations and engineering studies must all come together to make CLIC a reality.

Structural insight into catalytic mechanism of PET hydrolase

OpenAIRE

Han, Xu; Liu, Weidong; Huang, Jian-Wen; Ma, Jiantao; Zheng, Yingying; Ko, Tzu-Ping; Xu, Limin; Cheng, Ya-Shan; Chen, Chun-Chi; Guo, Rey-Ting

2017-01-01

PET hydrolase (PETase), which hydrolyzes polyethylene terephthalate (PET) into soluble building blocks, provides an attractive avenue for the bioconversion of plastics. Here we present the structures of a novel PETase from the PET-consuming microbe Ideonella sakaiensis in complex with substrate and product analogs. Through structural analyses, mutagenesis, and activity measurements, a substrate-binding mode is proposed, and several features critical for catalysis are elucidated.

Structural insight into catalytic mechanism of PET hydrolase.

Science.gov (United States)

Han, Xu; Liu, Weidong; Huang, Jian-Wen; Ma, Jiantao; Zheng, Yingying; Ko, Tzu-Ping; Xu, Limin; Cheng, Ya-Shan; Chen, Chun-Chi; Guo, Rey-Ting

2017-12-13

PET hydrolase (PETase), which hydrolyzes polyethylene terephthalate (PET) into soluble building blocks, provides an attractive avenue for the bioconversion of plastics. Here we present the structures of a novel PETase from the PET-consuming microbe Ideonella sakaiensis in complex with substrate and product analogs. Through structural analyses, mutagenesis, and activity measurements, a substrate-binding mode is proposed, and several features critical for catalysis are elucidated.

SM-like Higgs decay into two muons at 1.4 TeV CLIC

CERN Document Server

Milutinovic-Dumbelovic, Gordana

2016-06-02

The branching fraction measurement of the SM-like Higgs boson decay into two muons at 1.4 TeV CLIC will be described in this paper contributed to the LCWS13. The study is performed in the fully simulated ILD detector concept for CLIC, taking into consideration all the relevant physics and the beam-induced backgrounds, as well as the instrumentation of the very forward region to tag the high-energy electrons. Higgs couplings are known to be sensitive to BSM physics and we prove that BR times the Higgs production cross section can be measured with approximately 35.5% statistical accuracy in four years of the CLIC operation at 1.4 TeV centre-of-mass energy with unpolarised beams. The result is preliminary as the equivalent photon approximation is not considered in the cross-section calculations. This study complements the Higgs physics program foreseen at CLIC.

Test facility for investigation of heating of 30 GHz accelerating structure imitator for the CLIC project

International Nuclear Information System (INIS)

Elzhov, A.V.; Ginzburg, N.S.; Kaminsky, A.K.; Kuzikov, S.V.; Perelstein, E.A.; Peskov, N.Yu.; Petelin, M.I.; Sedykh, S.N.; Sergeev, A.P.; Sergeev, A.S.; Syratchev, I.; Zaitsev, N.I.

2004-01-01

Since 2001 an experimental test facility for investigation of lifetime of a copper material, with respect to multiple RF pulse actions, was set up on the basis of the JINR (Dubna) FEM oscillator, in collaboration with IAP RAS (Nizhny Novgorod). A high-Q copper cavity, which simulates the parameters of the accelerating structure of the collider CLIC at an operating frequency of 30 GHz, is used in the investigation. The experimental setup consists of a wavebeam injector--FEM oscillator (power of ∼25 MW, pulse duration up to 200 ns, spectral bandwidth not higher than 0.1%), a quasi-optic two-mirror transmission line, a wave-type converter, and a testing cavity. The frequency and transmission features of the components of the quasi-optic line were analyzed

Strategy and validation of fiducialisation for the pre-alignment of CLIC components

CERN Document Server

Griffet, S; Kemppinen, J; Mainaud Durand, H; Rude, V; Sterbini, G

2012-01-01

The feasibility of the high energy e+ e- linear collider CLIC (Compact Linear Collider) is very dependent on the ability to accurately pre-align its components. There are two 20 km long Main Linacs which meet in an interaction point (IP). The Main Linacs are composed of thousands of 2 m long modules. One of the challenges is to meet very tight alignment tolerances at the level of CLIC module: for example, the magnetic centre of a Drive Beam Quad needs to be aligned within 20 µm rms with respect to a straight line. Such accuracies cannot be achieved using usual measurement devices. Thus it is necessary to work in close collaboration with the metrology lab. To test and improve many critical points, including alignment, a CLIC mock-up is being assembled at CERN. This paper describes the application of the strategy of fiducialisation for the pre-alignment of CLIC mock-up components. It also deals with the first results obtained by performing measurements using a CMM (Coordinate Measuring Machine) to ensure the f...

Sensitivity Analysis for the CLIC Damping Ring Inductive Adder

CERN Document Server

Holma, Janne

2012-01-01

The CLIC study is exploring the scheme for an electron-positron collider with high luminosity and a nominal centre-of-mass energy of 3 TeV. The CLIC pre-damping rings and damping rings will produce, through synchrotron radiation, ultra-low emittance beam with high bunch charge, necessary for the luminosity performance of the collider. To limit the beam emittance blow-up due to oscillations, the pulse generators for the damping ring kickers must provide extremely flat, high-voltage pulses. The specifications for the extraction kickers of the CLIC damping rings are particularly demanding: the flattop of the output pulse must be 160 ns duration, 12.5 kV and 250 A, with a combined ripple and droop of not more than ±0.02 %. An inductive adder allows the use of different modulation techniques and is therefore a very promising approach to meeting the specifications. PSpice has been utilised to carry out a sensitivity analysis of the predicted output pulse to the value of both individual and groups of circuit compon...

Silicon technologies for the CLIC vertex detector

Science.gov (United States)

Spannagel, S.

2017-06-01

CLIC is a proposed linear e+e- collider designed to provide particle collisions at center-of-mass energies of up to 3 TeV. Precise measurements of the properties of the top quark and the Higgs boson, as well as searches for Beyond the Standard Model physics require a highly performant CLIC detector. In particular the vertex detector must provide a single point resolution of only a few micrometers while not exceeding the envisaged material budget of around 0.2% X0 per layer. Beam-beam interactions and beamstrahlung processes impose an additional requirement on the timestamping capabilities of the vertex detector of about 10 ns. These goals can only be met by using novel techniques in the sensor and ASIC design as well as in the detector construction. The R&D program for the CLIC vertex detector explores various technologies in order to meet these demands. The feasibility of planar sensors with a thickness of 50-150 μm, including different active edge designs, are evaluated using Timepix3 ASICs. First prototypes of the CLICpix readout ASIC, implemented in 65 nm CMOS technology and with a pixel size of 25×25μm 2, have been produced and tested in particle beams. An updated version of the ASIC with a larger pixel matrix and improved precision of the time-over-threshold and time-of-arrival measurements has been submitted. Different hybridization concepts have been developed for the interconnection between the sensor and readout ASIC, ranging from small-pitch bump bonding of planar sensors to capacitive coupling of active HV-CMOS sensors. Detector simulations based on Geant 4 and TCAD are compared with experimental results to assess and optimize the performance of the various designs. This contribution gives an overview of the R&D program undertaken for the CLIC vertex detector and presents performance measurements of the prototype detectors currently under investigation.

arXiv Dimension-6 Operator Analysis of the CLIC Sensitivity to New Physics

CERN Document Server

Ellis, John; Sanz, Veronica; You, Tevong

2017-05-17

We estimate the possible accuracies of measurements at the proposed CLIC e$^{+}$ e$^{−}$ collider of Higgs and W$^{+}$ W$^{−}$ production at centre-of-mass energies up to 3 TeV, incorporating also Higgsstrahlung projections at higher energies that had not been consid-ered previously, and use them to explore the prospective CLIC sensitivities to decoupled new physics. We present the resulting constraints on the Wilson coefficients of dimension-6 operators in a model-independent approach based on the Standard Model effective field theory (SM EFT). The higher centre-of-mass energy of CLIC, compared to other projects such as the ILC and CEPC, gives it greater sensitivity to the coefficients of some of the operators we study. We find that CLIC Higgs measurements may be sensitive to new physics scales $ \\Lambda =\\mathcal{O}(10) $ TeV for individual operators, reduced to $ \\mathcal{O}(1) $ TeV sensitivity for a global fit marginalising over the coefficients of all contributing operators. We give some examples of...

The CLIC Study of a Multi-TeV $e^\\pm$ Linear Collider

CERN Document Server

Bossart, Rudolf; Carron, G; Coosemans, Williame; Corsini, R; D'Amico, T E; Delahaye, J P; Godot, J C; Guignard, Gilbert; Hagel, J; Hutchins, S; Jensen, E; Luong, M; Millich, Antonio; Pearce, P; Potier, J P; Riche, A J; Rinolfi, Louis; Schulte, Daniel; Suberlucq, Guy; Thorndahl, L; Valentini, M; Wilson, Ian H; Wuensch, Walter; Napoly, O; Raubenheimer, T O; Ruth, Ronald D; Syratchev, I V

1999-01-01

The progress of the Compact LInear Collider (CLIC) study of a multi-TeV (0.5 - 5 TeV) high-luminosity (5'1033 to 1.5'1035 cm-2 sec-1) e± linear collider based on Two-Beam Acceleration (TBA) is presented. The length and, in consequence, the cost of the overall complex is reduced by the use of high accelerating fields (150 MV/m), which are generated by specially damped 30 GHz normal-conducting accelerating structures. The large amount of RF power (400 MW/m) required to generate these high fields is provided by a novel RF power generating scheme which is potentially both cost and power efficient. After summarising the progress made in the developments of 30 GHz components and the performance obtained in the present phase of the CLIC Test Facility (CTF2), the design of a new test facility (CTF3), which will demonstrate the feasibility of the RF power generating scheme, is described

Thermo-mechanical modelling and experimental validation of CLIC prototype module type 0

CERN Document Server

Kortelainen, Lauri; Koivurova, Hannu; Riddone, Germana; Österberg, Kenneth

Micron level stability of the two-meter repetitive modules constituting the two main linacs is one of the most important requirements to achieve the luminosity goal for the Compact Linear Collider. Structural deformations due to thermal loads and related to the RF power dissipated inside the modules affect the alignment of the linacs and therefore the resulting luminosity performance. A CLIC prototype module has been assembled in a dedicated laboratory and a thermal test program has been started in order to study its thermo-mechanical behaviour. This thesis focuses on the finite elements modelling of the first CLIC prototype module 0. The aim of the modelling is to examine the temperature distributions and the resulting deformations of the module in different operating conditions defined in the thermal test program. The theoretical results have been compared to the experimental ones; the comparison shows that the results are in good agreement both for the thermal behaviour of the module and for the resulting ...

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

Energy Technology Data Exchange (ETDEWEB)

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

2011-11-21

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

Investigation into diode pumped modelocked Nd based laser oscillators for the CLIC-3 photoinjector system

NARCIS (Netherlands)

Valentine, G.J.; Burns, D.; Bente, E.A.J.M.; Berghmans, F.; Thienpont, H.; Danckaert, J.; Desmet, L.

2001-01-01

The photo-injector system envisaged for the proposed CLIC linear e+-e- accelerator at CERN has a demanding set of specifications on output pulse structure, power and timing stability. This paper reports on results obtained with quasi-CW diode pumped laser oscillators with output stabilisation. A

Test facility for investigation of heating of 30 GHz accelerating structure imitator for the CLIC project

CERN Document Server

Elzhov, A V; Kaminsky, A K; Kuzikov, S V; Perelshtejn, E A; Peskov, N Yu; Petelin, M I; Sedykh, S N; Sergeev, A P; Sergeev, A S; Syratchev, I V; Zaitsev, N I

2004-01-01

Since 2001 an experimental test facility for investigation of lifetime of a copper material, with respect to multiple RF pulse actions, was set up on the basis of the JINR (Dubna) FEM oscillator, in collaboration with IAP RAS (Nizhny Novgorod). A high-Q copper cavity, which simulates the parameters of the accelerating structure of the collider CLIC at an operating frequency of 30GHz, is used in the investigation. The experimental setup consists of a wavebeam injector - FEM oscillator (power of similar to 25MW, pulse duration up to 200ns, spectral bandwidth not higher than 0.1%), a quasi-optic two-mirror transmission line, a wave-type converter, and a testing cavity. The frequency and transmission features of the components of the quasi-optic line were analyzed.

CERN: Making CLIC tick

International Nuclear Information System (INIS)

Anon.

1990-01-01

While the Large Hadron Collider (LHC) scheme for counter-rotating proton beams in a new superconducting ring to be built in CERN's existing 27-kilometre LEP tunnel is being pushed as the Laboratory's main construction project for the 1990s, research and development continues in parallel for an eventual complementary attack on new physics frontiers with CERN's Linear Collider - CLIC - firing TeV electron and positron beams at each other

Proposal for an alignment method of the CLIC linear accelerator - From geodesic networks to the active pre-alignment

International Nuclear Information System (INIS)

Touze, T.

2011-01-01

The compact linear collider (CLIC) is the particle accelerator project proposed by the european organization for nuclear research (CERN) for high energy physics after the large hadron collider (LHC). Because of the nano-metric scale of the CLIC leptons beams, the emittance growth budget is very tight. It induces alignment tolerances on the positions of the CLIC components that have never been achieved before. The last step of the CLIC alignment will be done according to the beam itself. It falls within the competence of the physicists. However, in order to implement the beam-based feedback, a challenging pre-alignment is required: 10 μm at 3σ along a 200 m sliding window. For such a precision, the proposed solution must be compatible with a feedback between the measurement and repositioning systems. The CLIC pre-alignment will have to be active. This thesis does not demonstrate the feasibility of the CLIC active pre-alignment but shows the way to the last developments that have to be done for that purpose. A method is proposed. Based on the management of the Helmert transformations between Euclidean coordinate systems, from the geodetic networks to the metrological measurements, this method is likely to solve the CLIC pre-alignment problem. Large scale facilities have been built and Monte-Carlo simulations have been made in order to validate the mathematical modeling of the measurement systems and of the alignment references. When this is done, it will be possible to extrapolate the modeling to the entire CLIC length. It will be the last step towards the demonstration of the CLIC pre-alignment feasibility. (author)

Higgs physics at the CLIC electron-positron linear collider.

Science.gov (United States)

Abramowicz, H; Abusleme, A; Afanaciev, K; Alipour Tehrani, N; Balázs, C; Benhammou, Y; Benoit, M; Bilki, B; Blaising, J-J; Boland, M J; Boronat, M; Borysov, O; Božović-Jelisavčić, I; Buckland, M; Bugiel, S; Burrows, P N; Charles, T K; Daniluk, W; Dannheim, D; Dasgupta, R; Demarteau, M; Díaz Gutierrez, M A; Eigen, G; Elsener, K; Felzmann, U; Firlej, M; Firu, E; Fiutowski, T; Fuster, J; Gabriel, M; Gaede, F; García, I; Ghenescu, V; Goldstein, J; Green, S; Grefe, C; Hauschild, M; Hawkes, C; Hynds, D; Idzik, M; Kačarević, G; Kalinowski, J; Kananov, S; Klempt, W; Kopec, M; Krawczyk, M; Krupa, B; Kucharczyk, M; Kulis, S; Laštovička, T; Lesiak, T; Levy, A; Levy, I; Linssen, L; Lukić, S; Maier, A A; Makarenko, V; Marshall, J S; Martin, V J; Mei, K; Milutinović-Dumbelović, G; Moroń, J; Moszczyński, A; Moya, D; Münker, R M; Münnich, A; Neagu, A T; Nikiforou, N; Nikolopoulos, K; Nürnberg, A; Pandurović, M; Pawlik, B; Perez Codina, E; Peric, I; Petric, M; Pitters, F; Poss, S G; Preda, T; Protopopescu, D; Rassool, R; Redford, S; Repond, J; Robson, A; Roloff, P; Ros, E; Rosenblat, O; Ruiz-Jimeno, A; Sailer, A; Schlatter, D; Schulte, D; Shumeiko, N; Sicking, E; Simon, F; Simoniello, R; Sopicki, P; Stapnes, S; Ström, R; Strube, J; Świentek, K P; Szalay, M; Tesař, M; Thomson, M A; Trenado, J; Uggerhøj, U I; van der Kolk, N; van der Kraaij, E; Vicente Barreto Pinto, M; Vila, I; Vogel Gonzalez, M; Vos, M; Vossebeld, J; Watson, M; Watson, N; Weber, M A; Weerts, H; Wells, J D; Weuste, L; Winter, A; Wojtoń, T; Xia, L; Xu, B; Żarnecki, A F; Zawiejski, L; Zgura, I-S

2017-01-01

The Compact Linear Collider (CLIC) is an option for a future [Formula: see text] collider operating at centre-of-mass energies up to [Formula: see text], providing sensitivity to a wide range of new physics phenomena and precision physics measurements at the energy frontier. This paper is the first comprehensive presentation of the Higgs physics reach of CLIC operating at three energy stages: [Formula: see text], 1.4 and [Formula: see text]. The initial stage of operation allows the study of Higgs boson production in Higgsstrahlung ([Formula: see text]) and [Formula: see text]-fusion ([Formula: see text]), resulting in precise measurements of the production cross sections, the Higgs total decay width [Formula: see text], and model-independent determinations of the Higgs couplings. Operation at [Formula: see text] provides high-statistics samples of Higgs bosons produced through [Formula: see text]-fusion, enabling tight constraints on the Higgs boson couplings. Studies of the rarer processes [Formula: see text] and [Formula: see text] allow measurements of the top Yukawa coupling and the Higgs boson self-coupling. This paper presents detailed studies of the precision achievable with Higgs measurements at CLIC and describes the interpretation of these measurements in a global fit.

Study of the ALICE Investigator chip in view of the requirements at CLIC

CERN Document Server

AUTHOR|(SzGeCERN)754303; Dannheim, Dominik; Fiergolski, Adrian; Van Hoorne, Jacobus Willem; Hynds, Daniel; Klempt, Wolfgang; Nurnberg, Andreas Matthias; Sielewicz, Krzysztof Marek; Snoeys, Walter

2017-01-01

CLIC is an option for a future high energy linear $e^{+}e^{−}$ collider at CERN in the post-LHC era. The CLIC machine is designed to reach centre-of-mass energies ranging from a few hundred GeV up to 3 TeV. To achieve high precision measurements, e.g. of the Higgs- width, challenging requirements are imposed on the CLIC detector. A single point tracking resolution of 7 μm and a material budget of 1-2%$X_{0}$ per layer are required for the tracker. Moreover, to suppress background hits from beam-beam interactions, a precise time slicing of hits of 10 ns is needed. To address these requirements, a large area silicon tracker is foreseen for the detector at CLIC. In this context, integrated technologies are promising candidates to achieve large scale production and low material budget. The Investigator chip is a test chip developed for the ALICE Inner Tracking System upgrade, implemented in a 180 nm CMOS process on a high resistivity substrate. It contains various test-matrices with analogue functionality, whi...

Successful start for new CLIC test facility

CERN Document Server

2004-01-01

A new test facility is being built to study key feasibility issues for a possible future linear collider called CLIC. Commissioning of the first part of the facility began in June 2003 and nominal beam parameters have been achieved already.

Phase detection electronics for CLIC

CERN Document Server

Andersson, A

2011-01-01

The Compact Linear Collider (CLIC) requires very tight RF phase synchronisation in order to preserve high luminosity. The electronics required for processing the signals delivered from the phase pick-ups present a significant challenge. This paper discusses the strategy adopted to achieve a sufficiently accurate measurement of the phase. Performance measurements performed in the lab of some of the sub-systems are also presented.

Breakdown Studies for the CLIC Accelerating

CERN Document Server

Calatroni, S; Kovermann, J; Taborelli, M; Timko, H; Wuensch, W; Durabekova, F; Nordlund, K; Pohjonen, A; Kuronen, A

2010-01-01

Optimizing the design and the manufacturing of the CLIC RF accelerating structures for achieving the target value of breakdown rate at the nominal accelerating gradient of 100 MV/m requires a detailed understanding of all the steps involved in the mechanism of breakdown. These include surface modification under RF fields, electron emission and neutral evaporation in the vacuum, arc ignition and consequent surface modification due to plasma bombardment. Together with RF tests, experiments are conducted in a simple DC test set-up instrumented with electrical diagnostics and optical spectroscopy. The results are also used for validating simulations which are performed using a wide range of numerical tools (MD coupled to electrostatic codes, PIC plasma simulations) able to include all the above phenomena. Some recent results are presented in this paper

Mass and Cross Section Measurements of light-flavored Squarks at CLIC

CERN Document Server

WEUSTE, L.

2011-01-01

We present a study of the prospects for the measurement of TeV-scale light-flavored right-squark masses and and the production cross sections at a 3 TeV e+e- collider based on CLIC technology. The analysis, performed in the framework of the CLIC Conceptual Design Report, is based on full Geant4 simulations of the CLIC ILD detector concept, including standard model physics background and machine related hadronic background from two-photon processes. The events were reconstructed using particle flow event reconstruction, and the mass and cross sections were obtained from a template fit built from generator-level simulations with smearing to parametrize the detector response. For an integrated luminosity of 2 ab^-1, a statistical precision of 5.9 GeV, corresponding to 0.52%, was obtained for unseparated first and second generation right squarks. For the combined cross section, a precision of 0.07 fb, corresponding to 5%, was obtained.

Status of the CLIC study on magnet stabilisation and time-dependent luminosity

CERN Document Server

Assmann, R W; Guignard, Gilbert; Leros, Nicolas; Redaelli, S; Schnell, Wolfgang; Schulte, Daniel; Wilson, Ian H; Zimmermann, Frank

2002-01-01

The nanometer beam size at the CLIC interaction point imposes magnet vibration tolerances that range from 0.2 nm to a few nanometers. This is well below the floor vibra-tion usually observed. A test stand for magnet stability was set-up at CERN in the immediate neighborhood of roads, operating accelerators, manual shops, and regular office space. It was equipped with modern stabilization tech-nology. First results are presented, demonstrating signif-icant damping of floor vibration. CLIC quadrupoles have been stabilized vertically to an rms motion of (0.9 ± 0.1) n above 4 Hz, or (1.3 ± 0.2) nm with a nominal flow of cooling water. For the horizontal and longitudinal directions respectively, a CLIC quadrupole was stabilized to (0.4 ± 0.1) nm and (3.2 ± 0.4) nm.

Inhibition of CLIC4 enhances autophagy and triggers mitochondrial and ER stress-induced apoptosis in human glioma U251 cells under starvation.

Directory of Open Access Journals (Sweden)

Jiateng Zhong

Full Text Available CLIC4/mtCLIC, a chloride intracellular channel protein, localizes to mitochondria, endoplasmic reticulum (ER, nucleus and cytoplasm, and participates in the apoptotic response to stress. Apoptosis and autophagy, the main types of the programmed cell death, seem interconnected under certain stress conditions. However, the role of CLIC4 in autophagy regulation has yet to be determined. In this study, we demonstrate upregulation and nuclear translocation of the CLIC4 protein following starvation in U251 cells. CLIC4 siRNA transfection enhanced autophagy with increased LC3-II protein and puncta accumulation in U251 cells under starvation conditions. In that condition, the interaction of the 14-3-3 epsilon isoform with CLIC4 was abolished and resulted in Beclin 1 overactivation, which further activated autophagy. Moreover, inhibiting the expression of CLIC4 triggered both mitochondrial apoptosis involved in Bax/Bcl-2 and cytochrome c release under starvation and endoplasmic reticulum stress-induced apoptosis with CHOP and caspase-4 upregulation. These results demonstrate that CLIC4 nuclear translocation is an integral part of the cellular response to starvation. Inhibiting the expression of CLIC4 enhances autophagy and contributes to mitochondrial and ER stress-induced apoptosis under starvation.

Transverse stability in multibunch mode for CLIC

International Nuclear Information System (INIS)

Guignard, G.

1993-01-01

In order to reach the desired luminosity with 250 GeV per beam, multibunch operation (limited to 4 bunches, say) might have to be considered in the CERN linear collider (CLIC). One limitation comes from the coupling of the bunch motion with the long-range transverse wake fields that may induce beam breakup. These wake fields have therefore to be controlled, and means of reducing their effects on the beam are discussed in a companion paper. One possibility consists in detuning the dipole modes in the cells to obtain decoherent contributions and hence reduce the field amplitude at the downstream bunch location. The important question is to know below which value this amplitude must be limited to prevent intolerable beam breakup. In a first attempt at estimating this threshold for CLIC two approaches are considered, i.e. the criterion developed at SLAC and based on the convergence of the multibunch-motion solution, and numerical simulations of two-bunch motion in a focusing lattice

Proposition d'une méthode d'alignement de l'accélérateur linéaire CLIC

CERN Document Server

Touzé, Thomas; Mainaud-Durand, H

2011-01-01

The compact linear collider (CLIC) is the particles accelerator project proposed by the european organization for nuclear research (CERN) for high energy physics after the large hadron collider (LHC). Because of the nanometric scale of the CLIC leptons beams, the emittance growth budget is very tight. It induces alignment tolerances on the positions of the CLIC components that have never been achieved. The last step of the CLIC alignment will be done according to the beam itself. It falls within the competence of the physicists. However, in order to implement the beam-based feedback, a challenging pre-alignment is required : 10 μm at 3σ along a 200 m sliding window. For such a precision, the proposed solution must be compatible with a feedback between the measurement and repositioning systems. The CLIC pre-alignment will have to be active. This thesis does not demonstrate the feasibility of the CLIC active prealignment but shows the way to the last developments that have to be done for that purpose. A metho...

Top Quark Pair Production at a 500 GeV CLIC Collider

CERN Document Server

Seidel, K; Simon, F

2012-01-01

We present a study of the capability of a 500 GeV e+e− collider based on the CLIC technology for precision measurements of top quark properties. The analysis is based on full detector simulations of the CLIC ILD detector concept using Geant4, including realistic beam-induced background contributions from two photon processes. Event reconstruction is performed using a particle flow algorithm with stringent cuts to control the influence of background. The mass and width of the top quark are studied in fully-hadronic and semi-leptonic decays of tt ̄ pairs using event samples of signal and standard model background processes corresponding to an integrated luminosity of 100fb−1. Statistical uncertainties of the top mass of 0.08 GeV and 0.09 GeV were obtained for the fully-hadronic channel and the semi-leptonic channel, respectively. The results are compared to a similar analysis performed within the framework of the ILC, showing that a similar precision can be achieved at CLIC despite less favorable experimen...

Engineering study, development and prototype fabrication of the supporting system for the CLIC Two-Beam Module

CERN Document Server

AUTHOR|(CDS)2068725; Karyotakis, Yannis; Dahoo, Pierre Richard; Alexopoulos, Theo; MEIS, Costantin; De Conto, Jean Marie; Jeremie, Andrea; Puzot, Patrique

CERN, the European Organization for Nuclear Research, is based on the international collaboration in the field of high-energy particle physics research. The experiments carried out in its facilities are achieved through the existing particle accelerators. In addition, advanced accelerator research and development is one of the goals of CERN. For this reason, CLIC (the Compact LInear Collider) a new electron-positron linear accelerator is being studied at CERN. CLIC is built by the assembly of the Two-Beam Modules and takes advantage of an innovative acceleration principle, the Two-Beam acceleration. Each Module contains several technical systems that contribute to its successful operation. This thesis presents the development of the prototype supporting system for the CLIC Two-Beam Module. At first, the physics requirements are translated into technical specifications and the fundamental parts of the supporting system are defined. The CLIC operational conditions are identified and the corresponding boundaries...

Higgs physics at the CLIC electron-positron linear collider

Energy Technology Data Exchange (ETDEWEB)

Abramowicz, H.; Benhammou, Y.; Borysov, O.; Kananov, S.; Levy, A.; Levy, I.; Rosenblat, O. [Tel Aviv University, Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv (Israel); Abusleme, A.; Diaz Gutierrez, M.A.; Vogel Gonzalez, M. [Pontificia Universidad Catolica de Chile, Santiago (Chile); Afanaciev, K.; Makarenko, V.; Shumeiko, N. [Belarusian State University, National Scientific and Educational Centre of Particle and High Energy Physics, Minsk (Belarus); Alipour Tehrani, N.; Dannheim, D.; Elsener, K.; Grefe, C.; Hauschild, M.; Hynds, D.; Klempt, W.; Kulis, S.; Linssen, L.; Maier, A.A.; Muenker, R.M.; Muennich, A.; Nikiforou, N.; Nuernberg, A.; Perez Codina, E.; Petric, M.; Pitters, F.; Poss, S.G.; Redford, S.; Roloff, P.; Sailer, A.; Schlatter, D.; Schulte, D.; Sicking, E.; Simoniello, R.; Stapnes, S.; Stroem, R.; Strube, J.; Weber, M.A. [CERN, Geneva (Switzerland); Balazs, C.; Charles, T.K. [Monash University, Melbourne (Australia); Benoit, M.; Vicente Barreto Pinto, M. [Universite de Geneve, Departement de Physique Nucleaire et Corpusculaire (DPNC), Geneva (Switzerland); Bilki, B.; Demarteau, M.; Repond, J.; Weerts, H.; Xia, L. [Argonne National Laboratory, Argonne, IL (United States); Blaising, J.J. [Laboratoire d' Annecy-le-Vieux de Physique des Particules, Annecy-le-Vieux (France); Boland, M.J.; Felzmann, U.; Rassool, R. [University of Melbourne, Melbourne (Australia); Boronat, M.; Fuster, J.; Garcia, I.; Ros, E.; Vos, M. [CSIC-University of Valencia, IFIC, Valencia (Spain); Bozovic-Jelisavcic, I.; Kacarevic, G.; Lukic, S.; Milutinovic-Dumbelovic, G.; Pandurovic, M. [University of Belgrade, Vinca Institute of Nuclear Sciences, Belgrade (Serbia); Buckland, M.; Vossebeld, J. [University of Liverpool, Liverpool (United Kingdom); Bugiel, S.; Dasgupta, R.; Firlej, M.; Fiutowski, T.; Idzik, M.; Kopec, M.; Moron, J.; Swientek, K.P. [AGH University of Science and Technology, Faculty of Physics and Applied Computer Science, Crakow (Poland); Burrows, P.N. [Oxford University, Oxford (United Kingdom); Daniluk, W.; Krupa, B.; Kucharczyk, M.; Lesiak, T.; Moszczynski, A.; Pawlik, B.; Sopicki, P.; Wojton, T.; Zawiejski, L. [The Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, Crakow (Poland); Eigen, G.; Kraaij, E. van der [University of Bergen, Department of Physics and Technology, Bergen (Norway); Firu, E.; Ghenescu, V.; Neagu, A.T.; Preda, T.; Zgura, I.S. [Institute of Space Science, Bucharest (Romania); Gabriel, M.; Simon, F.; Szalay, M.; Tesar, M.; Kolk, N. van der; Weuste, L. [Max-Planck-Institut fuer Physik, Munich (Germany); Gaede, F. [CERN, Geneva (Switzerland); DESY, Hamburg (Germany); Goldstein, J. [University of Bristol, Bristol (United Kingdom); Green, S.; Marshall, J.S.; Mei, K.; Thomson, M.A.; Xu, B. [University of Cambridge, Cavendish Laboratory, Cambridge (United Kingdom); Hawkes, C.; Nikolopoulos, K.; Watson, M.; Watson, N.; Winter, A. [University of Birmingham, School of Physics and Astronomy, Birmingham (United Kingdom); Kalinowski, J.; Krawczyk, M.; Zarnecki, A.F. [University of Warsaw, Faculty of Physics, Warsaw (Poland); Lastovicka, T. [Institute of Physics of the Academy of Sciences of the Czech Republic, Prague (Czech Republic); Martin, V.J. [University of Edinburgh, Edinburgh (United Kingdom); Moya, D.; Ruiz-Jimeno, A.; Vila, I. [CSIC-University of Cantabria, IFCA, Santander (Spain); Peric, I. [Institut fuer Prozessdatenverarbeitung und Elektronik (IPE), Karlsruher Institut fuer Technologie (KIT), Karlsruhe (Germany); Protopopescu, D.; Robson, A. [University of Glasgow, Glasgow (United Kingdom); Trenado, J. [University of Barcelona, Barcelona (ES); Uggerhoej, U.I. [Aarhus University, Aarhus (DK); Wells, J.D. [University of Michigan, Physics Department, Ann Arbor, MI (US)

2017-07-15

The Compact Linear Collider (CLIC) is an option for a future e{sup +}e{sup -} collider operating at centre-of-mass energies up to 3 TeV, providing sensitivity to a wide range of new physics phenomena and precision physics measurements at the energy frontier. This paper is the first comprehensive presentation of the Higgs physics reach of CLIC operating at three energy stages: √(s) = 350 GeV, 1.4 and 3 TeV. The initial stage of operation allows the study of Higgs boson production in Higgsstrahlung (e{sup +}e{sup -} → ZH) and WW-fusion (e{sup +}e{sup -} → Hν{sub e} anti ν{sub e}), resulting in precise measurements of the production cross sections, the Higgs total decay width Γ{sub H}, and model-independent determinations of the Higgs couplings. Operation at √(s) > 1 TeV provides high-statistics samples of Higgs bosons produced through WW-fusion, enabling tight constraints on the Higgs boson couplings. Studies of the rarer processes e{sup +}e{sup -} → t anti tH and e{sup +}e{sup -} → HHν{sub e} anti ν{sub e} allow measurements of the top Yukawa coupling and the Higgs boson self-coupling. This paper presents detailed studies of the precision achievable with Higgs measurements at CLIC and describes the interpretation of these measurements in a global fit. (orig.)

Energy and Beam-Offset dependence of the Luminosity weighted depolarization for CLIC

CERN Document Server

Esberg, Jakob; Uggerhoj, Ulrik; Dalena, Barbara

2011-01-01

We report on simulations of e+e- depolarization due to beam-beam effects. These effects are studied for CLIC at 3 TeV, using GUINEA PIG++. We find a strong energy dependence of the luminosity weighted depolarization. In the luminosity peak at CLIC the total luminosity weighted depolarization remains below the one per-mil level. The effect of a vertical offset on the energy dependent depolarization is investigated. The depolarization in the luminosity peak remains below per-cent level even for 5sy offsets.

Common ground in ILC and CLIC detector concepts

CERN Multimedia

Daisy Yuhas

2013-01-01

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

Development of a Beam-based Phase Feedforward Demonstration at the CLIC Test Facility (CTF3)

CERN Document Server

AUTHOR|(CDS)2083344; Christian, Glenn

The Compact Linear Collider (CLIC) is a proposal for a future linear electron--positron collider that could achieve collision energies of up to 3~TeV. In the CLIC concept the main high energy beam is accelerated using RF power extracted from a high intensity drive beam, achieving an accelerating gradient of 100~MV/m. This scheme places strict tolerances on the drive beam phase stability, which must be better than $0.2^\\circ$ at 12~GHz. To achieve the required phase stability CLIC proposes a high bandwidth (${>}17.5$~MHz), low latency drive beam ``phase feedforward'' (PFF) system. In this system electromagnetic kickers, powered by 500~kW amplifiers, are installed in a chicane and used to correct the phase by deflecting the beam on to longer or shorter trajectories. A prototype PFF system has been installed at the CLIC Test Facility, CTF3; the design, operation and commissioning of which is the focus of this work. Two kickers have been installed in the pre-existing chicane in the TL2 transfer line at CTF3 for t...

Occupancy in the CLIC_ILD Time Projection Chamber

CERN Document Server

KILLENBERG, M.

2011-01-01

We report on the occupancy in the CLIC ILD TPC caused by the beam induced background from gg !hadrons, e+e- pairs and beam halo muons. In addition the particle composition of the backgrounds and the origin of back-scattering particles have been studied.

En route vers la nano stabilisation de CLIC faisceau principale et focalisation finale

CERN Document Server

Artoos, K; Guinchard, M; Hauviller, Claude; Lackner, F; CERN. Geneva. TS Department

2008-01-01

Pour atteindre la luminosité voulue de CLIC, la taille transversale du faisceau doit être de l?ordre du nanomètre. Ceci nécessite une stabilité vibratoire des quadripôles du faisceau principal de 1 nm et même 0.1 nm pour les doublets de la focalisation finale. La nano technologie et la nano stabilisation sont des activités qui évoluent rapidement dans l?industrie et centres de recherche pour des applications très variées comme l?électronique, l?optique, la chimie voire la médecine. Cette présentation décrit les avancées techniques nécessaires pour atteindre l?objectif de CLIC et les projets et collaborations R&D prévus pour démontrer la faisabilité de la nano stabilisation de CLIC en 2010.

SM-like Higgs decay into two muons at 1.4 TeV CLIC

CERN Document Server

Milutinovic-Dumbelovic, G

2014-01-01

The potential for measuring the Standard Model (SM) Higgs boson decay into two muons at a 1.4 TeV CLIC e+e− collider is addressed in this paper, that was presented at ICHEP2014. The study is performed in the full Geant4 detector simulations of CLIC_ILD, taking into consideration all the relevant physics and the beam-induced background processes, as well as the instrumentation of the very forward region to tag forward electrons. In this analysis we show that the branching ratio BR(H-->mu+mu-) times the Higgs production cross-section can be measured with 38% statistical accuracy at √s =1.4 TeV using an integrated luminosity of 1.5 ab-1. This study is part of an ongoing comprehensive Higgs physics benchmark study covering various Higgs production processes and decay modes, currently being carried out to estimate the full Higgs physics potential of CLIC.

CLIC Telescope optimization with ALLPIX simulation

CERN Document Server

Qi, Wu

2015-01-01

A simulation study of CLIC-EUDET telescope resolution with MIMOSA 26 as reference sensors under DESY (5.6 GeV electron beam) and CERN-SPS (120-180 GeV pion^{-} beam) conditions. During the study, a virtual DUT sensor with cylindrical sensing area was defined and used with ALLPIX software. By changing the configuration of telescope, some results for DESY's setup were found agreeing with the theoretical calculation.

CLIC crab cavity design optimisation for maximum luminosity

Energy Technology Data Exchange (ETDEWEB)

Dexter, A.C., E-mail: a.dexter@lancaster.ac.uk [Lancaster University, Lancaster, LA1 4YR (United Kingdom); Cockcroft Institute, Daresbury, Warrington, WA4 4AD (United Kingdom); Burt, G.; Ambattu, P.K. [Lancaster University, Lancaster, LA1 4YR (United Kingdom); Cockcroft Institute, Daresbury, Warrington, WA4 4AD (United Kingdom); Dolgashev, V. [SLAC, Menlo Park, CA 94025 (United States); Jones, R. [University of Manchester, Manchester, M13 9PL (United Kingdom)

2011-11-21

The bunch size and crossing angle planned for CERN's compact linear collider CLIC dictate that crab cavities on opposing linacs will be needed to rotate bunches of particles into alignment at the interaction point if the desired luminosity is to be achieved. Wakefield effects, RF phase errors between crab cavities on opposing linacs and unpredictable beam loading can each act to reduce luminosity below that anticipated for bunches colliding in perfect alignment. Unlike acceleration cavities, which are normally optimised for gradient, crab cavities must be optimised primarily for luminosity. Accepting the crab cavity technology choice of a 12 GHz, normal conducting, travelling wave structure as explained in the text, this paper develops an analytical approach to optimise cell number and iris diameter.

CLIC Detector Concepts as described in the CDR: Differences between the GEANT4 and Engineering Models

CERN Document Server

Elsener, K; Schlatter, D; Siegrist, N

2011-01-01

The CLIC_ILD and CLIC_SiD detector concepts as used for the CDR Vol. 2 in 2011 exist both in GEANT4 simulation models and in engineering layout drawings. At this early stage of a conceptual design, there are inevitably differences between these models, which are described in this note.

Vector boson scattering at CLIC

Energy Technology Data Exchange (ETDEWEB)

Kilian, Wolfgang; Fleper, Christian [Department Physik, Universitaet Siegen, 57068 Siegen (Germany); Reuter, Juergen [DESY Theory Group, 22603 Hamburg (Germany); Sekulla, Marco [Institut fuer Theoretische Physik, Karlsruher Institut fuer Technologie, 76131 Karlsruhe (Germany)

2016-07-01

Linear colliders operating in a range of multiple TeV are able to investigate the details of vector boson scattering and electroweak symmetry breaking. We calculate cross sections with the Monte Carlo generator WHIZARD for vector boson scattering processes at the future linear e{sup +} e{sup -} collider CLIC. By finding suitable cuts, the vector boson scattering signal processes are isolated from the background. Finally, we are able to determine exclusion sensitivities on the non-Standard Model parameters of the relevant dimension eight operators.

Dynamics on the positron capture and accelerating sections of CLIC

CERN Document Server

Poirier, Freddy; Vivoli, Alessandro; Dadoun, Olivier; Lepercq, Pierre; Variola, Alessandro

2011-01-01

The CLIC Pre-Injector Linac for the e+ beam is composed of an Adiabatic Matching Device (AMD) followed by 4 (or 5) accelerating RF structures embedded in a solenoidal magnetic field. The accelerating sections are based on 2 GHz long travelling wave structures. In this note, the positrons capture strategy downstream the AMD is reviewed. The first RF structure can be phased either for full acceleration or for deceleration. In the latter case, the simulations results show that the number of e+ capture at the end of the 200 MeV Pre-Injector Linac is increased. Then the impact of the space charge is presented. Additional techniques are also studied to explore the potentiality of increasing the number of e+ namely an extra RF field at the beginning of the capture section and a higher solenoidal field.

CLIC-ACM: Acquisition and Control System

CERN Document Server

Bielawski, B; Magnoni, S

2014-01-01

CLIC [1] (Compact Linear Collider) is a world-wide collaboration to study the next terascale lepton collider, relying upon a very innovative concept of two-beamacceleration. In this scheme, the power is transported to the main accelerating structures by a primary electron beam. The Two Beam Module (TBM) is a compact integration with a high filling factor of all components: RF, Magnets, Instrumentation, Vacuum, Alignment and Stabilization. This paper describes the very challenging aspects of designing the compact system to serve as a dedicated Acquisition & Control Module (ACM) for all signals of the TBM. Very delicate conditions must be considered, in particular radiation doses that could reach several kGy in the tunnel. In such severe conditions shielding and hardened electronics will have to be taken into consideration. In addition, with more than 300 ADC&DAC channels per ACM and about 21000 ACMs in total, it appears clearly that power consumption will be an important issue. It is also obvious that...

A prototype cavity beam position monitor for the CLIC Main Beam

CERN Document Server

Cullinany , F; Joshi, N; Lyapin, A; Bastard, D; Calvo, E; Chritin, N; Guillot-Vignot, F; Lefevre, T; Søby, L; Wendt, M; Lunin, A; Yakovlev, V P; Smith, S

2012-01-01

The Compact Linear Collider (CLIC) places unprecedented demands on its diagnostics systems. A large number of cavity beam position monitors (BPMs) throughout the main linac and beam delivery system (BDS) must routinely perform with 50 nm spatial resolution. Multiple position measurements within a single 156 ns bunch train are also required. A prototype low-Q cavity beam position monitor has been designed and built to be tested on the CLIC Test Facility (CTF3) probe beam. This paper presents the latest measurements of the prototype cavity BPM and the design and simulation of the radio frequency (RF) signal processing electronics with regards to the final performance. Installation of the BPM in the CTF3 probe beamline is also discussed.

Generation of structural MR images from amyloid PET: Application to MR-less quantification.

Science.gov (United States)

Choi, Hongyoon; Lee, Dong Soo

2017-12-07

Structural magnetic resonance (MR) images concomitantly acquired with PET images can provide crucial anatomical information for precise quantitative analysis. However, in the clinical setting, not all the subjects have corresponding MR. Here, we developed a model to generate structural MR images from amyloid PET using deep generative networks. We applied our model to quantification of cortical amyloid load without structural MR. Methods: We used florbetapir PET and structural MR data of Alzheimer's Disease Neuroimaging Initiative database. The generative network was trained to generate realistic structural MR images from florbetapir PET images. After the training, the model was applied to the quantification of cortical amyloid load. PET images were spatially normalized to the template space using the generated MR and then standardized uptake value ratio (SUVR) of the target regions was measured by predefined regions-of-interests. A real MR-based quantification was used as the gold standard to measure the accuracy of our approach. Other MR-less methods, a normal PET template-based, multi-atlas PET template-based and PET segmentation-based normalization/quantification methods, were also tested. We compared performance of quantification methods using generated MR with that of MR-based and MR-less quantification methods. Results: Generated MR images from florbetapir PET showed visually similar signal patterns to the real MR. The structural similarity index between real and generated MR was 0.91 ± 0.04. Mean absolute error of SUVR of cortical composite regions estimated by the generated MR-based method was 0.04±0.03, which was significantly smaller than other MR-less methods (0.29±0.12 for the normal PET-template, 0.12±0.07 for multiatlas PET-template and 0.08±0.06 for PET segmentation-based methods). Bland-Altman plots revealed that the generated MR-based SUVR quantification was the closest to the SUVR values estimated by the real MR-based method. Conclusion

Summary of the BDS and MDI CLIC08 Working Group

CERN Document Server

Tomás, R; Ahmed, I; Ambatu, PK; Angal-Kalinin, D; Barlow, R; Baud, J P; Bolzon, B; Braun, H; Burkhardt, H; Burt, GC; Corsini, R; Dalena, B; Dexter, AC; Dolgashev, V; Elsener, K; Fernandez Hernando, JL; Gaillard, G; Geffroy, N; Jackson, F; Jeremie, A; Jones, RM; McIntosh, P; Moffeit, K; Peltier, F; Resta-López, J; Rumolo, G; Schulte, D; Seryi, A; Toader, A; Zimmermann, F

2008-01-01

This note summarizes the presentations held within the Beam Delivery System and Machine Detector Interface working group of the CLIC08 workshop. The written contributions have been provided by the presenters on a voluntary basis.

Simulated top-quark pair production in the CLIC_ILD detector

CERN Multimedia

CLIC, Compact Linear Collider Project

2017-01-01

Simulated production of a top-quark pair with a nominal collision energy of 3 TeV, in the CLIC_ILD detector. The event display show the reconstructed particles used as input for a jet clustering algorithm.

High frequency electromagnetic characterization of NEG properties for the CLIC damping rings

CERN Document Server

Koukovini-Platia, E; Zannini, C

2014-01-01

Coating materials will be used in the CLIC damping rings (DR) to suppress two-stream effects. In particular, NEG coating is necessary to suppress fast beam ion instabilities in the electron damping ring (EDR). The electromagnetic (EM) characterization of the material properties up to high frequencies is required for the impedance modeling of the CLIC DR components. The EM properties for frequencies of few GHz are determined with the waveguide method, based on a combination of experimental measurements of the complex transmission coefficient S21 and CST 3D EM simulations. The results obtained from a NEG-coated copper (Cu) waveguide are presented in this paper.

Online optimisation of the CLIC Drive Beam bunch train recombination at CTF3

CERN Document Server

AUTHOR|(CDS)2082483; Tecker, Frank

The Compact Linear Collider (CLIC) design is the leading alternative for a future multi-TeV "e^+e^−" linear collider. One of the key aspects of the design is the use of a Drive Beam as power source for the acceleration of the colliding beams. This work is focused on the optimisation of the set-up and the operations of the CLIC Drive Beam recombination at the CLIC Test Facility (CTF3) at CERN. The main effects that may affect the beam quality during the recombination are studied, with emphasis on orbit, transverse dynamics and beam energy effects. A custom methodology is used to analyse the problem, both from a theoretical and a numerical point of view. The aim is to provide first-order orbit and transverse optics constraints, which can be used as guidelines during the set-up of the beam recombination process. The developed techniques are applied at the CTF3, and the results are reported. The non-linear beam energy effects have been investigated by means of MAD-X simulations. The results show that these effe...

CLICs-dependent chloride efflux is an essential and proximal upstream event for NLRP3 inflammasome activation.

Science.gov (United States)

Tang, Tiantian; Lang, Xueting; Xu, Congfei; Wang, Xiaqiong; Gong, Tao; Yang, Yanqing; Cui, Jun; Bai, Li; Wang, Jun; Jiang, Wei; Zhou, Rongbin

2017-08-04

The NLRP3 inflammasome can sense different pathogens or danger signals, and has been reported to be involved in the development of many human diseases. Potassium efflux and mitochondrial damage are both reported to mediate NLRP3 inflammasome activation, but the underlying, orchestrating signaling events are still unclear. Here we show that chloride intracellular channels (CLIC) act downstream of the potassium efflux-mitochondrial reactive oxygen species (ROS) axis to promote NLRP3 inflammasome activation. NLRP3 agonists induce potassium efflux, which causes mitochondrial damage and ROS production. Mitochondrial ROS then induces the translocation of CLICs to the plasma membrane for the induction of chloride efflux to promote NEK7-NLRP3 interaction, inflammasome assembly, caspase-1 activation, and IL-1β secretion. Thus, our results identify CLICs-dependent chloride efflux as an essential and proximal upstream event for NLRP3 activation.The NLRP3 inflammasome is key to the regulation of innate immunity against pathogens or stress, but the underlying signaling regulation is still unclear. Here the authors show that chloride intracellular channels (CLIC) interface between mitochondria stress and inflammasome activation to modulate inflammatory responses.

High-Efficiency Klystron Design for the CLIC Project

CERN Document Server

Mollard, Antoine; Peauger, Franck; Plouin, Juliette; Beunas, Armel; Marchesin, Rodolphe

2017-01-01

The CLIC project requests new type of RF sources for the high power conditioning of the accelerating cavities. We are working on the development of a new kind of high-efficiency klystron to fulfill this need. This work is performed under the EuCARD-2 European program and involves theoretical and experimental study of a brand new klystron concept.

Validation of the CLIC alignment strategy on short range

CERN Document Server

Mainaud Durand, H; Griffet, S; Kemppinen, J; Rude, V; Sosin, M

2012-01-01

The pre-alignment of CLIC consists of aligning the components of linacs and beam delivery systems (BDS) in the most accurate possible way, so that a first pilot beam can circulate and allow the implementation of the beam based alignment. Taking into account the precision and accuracy needed: 10 µm rms over sliding windows of 200m, this pre-alignment must be active and it can be divided into two parts: the determination of a straight reference over 20 km, thanks to a metrological network and the determination of the component positions with respect to this reference, and their adjustment. The second part is the object of the paper, describing the steps of the proposed strategy: firstly the fiducialisation of the different components of CLIC; secondly, the alignment of these components on common supports and thirdly the active alignment of these supports using sensors and actuators. These steps have been validated on a test setup over a length of 4m, and the obtained results are analysed.

Brilliant positron sources for CLIC and other collider projects

CERN Document Server

Rinolfi, Louis; Dadoun, Olivier; Kamitani, Takuya; Strakhovenko, Vladimir; Variola, Alessandro

2013-01-01

The CLIC (Compact Linear Collider), as future linear collider, requires an intense positron source. A brief history is given up to the present baseline configuration which assumes unpolarized beams. A conventional scheme, with a single tungsten target as source of e-e+ pairs, has been studied several years ago. But, in order to reduce the beam energy deposition on the e+ target converter, a double-target system has been studied and proposed as baseline for CLIC. With this ‘‘hybrid target’’, the positron production scheme is based on the channeling process. A 5 GeV electron beam impinges on a thin crystal tungsten target aligned along its axis, enhancing the photon production by channeling radiation. A large number of photons are sent to a thick amorphous tungsten target, generating large number of e-e+ pairs, while the charged particles are bent away, reducing the deposited energy and the PEDD (Peak Energy Deposition Density). The targets parameters are optimized for the positron production. Polarize...

Measurement of the H$\\rightarrow$WW$^*$ Branching Ratio at 1.4TeV using the semileptonic final state at CLIC

CERN Document Server

AUTHOR|(SzGeCERN)762723; Watson, Nigel

2016-01-01

This note summarises a study to evaluate the potential to measure the H$\\rightarrow$WW$^*$ branching fraction at CLIC, 1.4TeV centre-of-mass energy, with the CLIC_ILD detector, using the WW$\\rightarrow$qql$\

Silicon pixel-detector R&D for CLIC

CERN Document Server

AUTHOR|(SzGeCERN)718101

2016-01-01

The physics aims at the future CLIC high-energy linear e+e- collider set very high precision requirements on the performance of the vertex and tracking detectors. Moreover, these detectors have to be well adapted to the experimental conditions, such as the time structure of the collisions and the presence of beam-induced backgrounds. The principal challenges are: a point resolution of a few μm, ultra-low mass (∼ 0.2% X${}_0$ per layer for the vertex region and ∼ 1 % X${}_0$ per layer for the outer tracker), very low power dissipation (compatible with air-flow cooling in the inner vertex region) and pulsed power operation, complemented with ∼ 10 ns time stamping capabilities. A highly granular all-silicon vertex and tracking detector system is under development, following an integrated approach addressing simultaneously the physics requirements and engineering constraints. For the vertex-detector region, hybrid pixel detectors with small pitch (25 μm) and analog readout are explored. For the outer trac...

High performance electronics for alignment regulation on the CLIC 30GHz modules

International Nuclear Information System (INIS)

Carrica, D.; Coosemans, W.; Pittin, R.

1999-01-01

CERN is studying a linear collider (CLIC) to obtain electron-positron collisions with centre-of-mass energies in the TeV range. To demonstrate the feasibility of CLIC, a test facility (CTF2) is being constructed. CTF2 consists of 4 identical modules, each 1.4 m long module consists of 2 linac with a girder and a doublet or a triplet quadrupole. Girders are elements that support mechanically the cavities of the accelerator while the main objective of the quadrupole is to focus particle beams. The alignment system has 2 principal utilities. The first is to pre-align the elements to make the beam pass through the aperture and produce signals in beam position monitors. In respect to these signals the girders and the quadrupoles are moved for making the definitive alignment. The second utility is to maintain the elements in this position. The alignment control system of CTF2 must regulate the position of the girders and quadrupoles with a precision < 10 μm. In fact an accuracy of 1 μ has been obtained on CTF2. Thanks to its flexibility and its simplicity, the system is expected to adapt easily to CLIC even if it means to control modules that involve up to a maximum of 384 motors and 896 sensors

Damping rings for CLIC

CERN Document Server

Jowett, John M; Zimmermann, Frank; Owen, H

2001-01-01

The Compact Linear Colider (CLIC) is designed to operate at 3 TeV centre-of-mass energy with a total luminosity of 10^35 cm^-2 s^-1. The overall system design leads to extremely demanding requirements on the bunch trains injected into the main libac at frequency of 100 Hz. In particular, the emittances of the intense bunches have to be about an order of magnitude smaller than presently achieved. We describe our approach to finding a damping ring design capable of meeting these requirements. Besides lattice design, emittance and damping rate considerations, a number of scattering and instability effects have to be incorporated into the optimisation of parameters. Among these, intra-bem scattering and the electron cloud effect are two of the most significant.

Design and characterization of a prototype stripline beam position monitor for the Clic Drive Beam*

CERN Document Server

Benot-Morell, A; Wendt, M; Nappa, J M; Tassan-Viol, J; Vilalte, S; Smith, S

2012-01-01

The prototype of a stripline Beam Position Monitor (BPM) with its associated readout electronics is under development at CERN, in collaboration with SLAC, LAPP and IFIC. The anticipated position resolution and accuracy are expected to be below 2μm and 20μm respectively for operation of the BPM in the CLIC drive beam (DB) linac. This paper describes the particular CLIC DB conditions with respect to the beam position monitoring, presents the measurement concept, and summarizes electromagnetic simulations and RF measurements performed on the prototype.

Fast Beam-ion Instabilities in CLIC Main Linac Vacuum Specifications

CERN Document Server

Oeftiger, Adrian

2011-01-01

Specifications for the vacuum pressure in the CLIC electron Main Linac are determined by the onset of the fast beam-ion instability (FBII). When the electron beam is accelerated in the Main Linac, it ionizes the residual gas in the chamber through scattering ionization. If the density of ions around the beam exceeds a certain threshold, a resonant motion between the electron beam and the ions can be excited. A two-stream instability appears and as a result the beam acquires a coherent motion, which can quickly lead to beam quality degradation or even complete loss. Thus, the vacuum pressure must be kept below this threshold to prevent the excitation of FBII. The CLIC Main Linac poses an additional challenge with respect to previous FBII situations, because the gas ionization does not solely occur via scattering. The submicrometric beam sizes lead to extremely high electric fields around the beam and therefore result in field ionization beyond a certain threshold. The residual gas in the corresponding volume a...

Integrated CMOS sensor technologies for the CLIC tracker

CERN Document Server

AUTHOR|(SzGeCERN)754303

2017-01-01

Integrated technologies are attractive candidates for an all silicon tracker at the proposed future multi-TeV linear e+e- collider CLIC. In this context CMOS circuitry on a high resistivity epitaxial layer has been studied using the ALICE Investigator test-chip. Test-beam campaigns have been performed to study the Investigator performance and a Technology Computer Aided Design based simulation chain has been developed to further explore the sensor technology.

Hidden Valley searches at CLIC

CERN Document Server

Kucharczyk, Marcin

2018-01-01

Several beyond the Standard Model theoretical models predict the decay of Higgs bosons decaying into heavy long-lived particles. The sensitivity to observe such long-lived particles has been determined using a data sample of e$^+$e$^-$ collisions at $\\sqrt{s}=$3 TeV, simulated with the CLIC_ILD detector model and corresponding to an integrated luminosity of 3 ab$^{-1}$. The analysis identifies secondary vertices which can be associated with the decay of such particles. Decay products are subsequently combined to reconstruct the parent bosons. The sensitivity range covers long-lived particle lifetimes from 1 to 300 ps, masses between 25 and 50 GeV/c$^2$, and a parent Higgs mass of 126 GeV/c$^2$.

Conceptual Design for CLIC Gun Pulser

Energy Technology Data Exchange (ETDEWEB)

Tang, Tao [SLAC National Accelerator Lab., Menlo Park, CA (United States)

2016-01-08

The Compact Linear Collider (CLIC) is a proposed future electron-positron collider, designed to perform collisions at energies from 0.5 to 5 TeV, with a nominal design optimized for 3 TeV (Dannheim, 2012). The Drive Beam Accelerator consists of a thermionic DC gun, bunching section and an accelerating section. The thermionic gun needs deliver a long (~143us) pulse of current into the buncher. A pulser is needed to drive grid of the gun to generate a stable current output. This report explores the requirements of the gun pulser and potential solutions to regulate grid current.

Silicon pixel R&D for the CLIC detector

CERN Document Server

AUTHOR|(SzGeCERN)674552

2017-01-01

The physics aims at the future CLIC high-energy linear $e^{+}e^{−}$ collider set very high precision requirements on the performance of the vertex and tracking detectors. Moreover, these detectors have to be well adapted to the experimental conditions, such as the time structure of the collisions and the presence of beam-induced backgrounds. The main challenges are: a point resolution of a few microns, ultra-low mass (~0.2% X$_{0}$ per layer for the vertex region and ~1% X$_{0}$ per layer for the outer tracker), very low power dissipation (compatible with air-flow cooling in the inner vertex region) and pulsed power operation, complemented with ~10 ns time stamping capabilities. A highly granular all-silicon vertex and tracking detector system is under development, following an integrated approach addressing simultaneously the physics requirements and engineering constraints. For the vertex-detector region, hybrid pixel detectors with small pitch (25 μm) and analogue readout are explored. For the outer tra...

CLIC, a Multi-TeV $e^{\\pm}$ Linear Collider

CERN Document Server

Delahaye, J P; Bossart, Rudolf; Braun, Hans Heinrich; Carron, G; Coosemans, Williame; Corsini, R; D'Amico, T E; Godot, J C; Guignard, Gilbert; Hutchins, S; Jensen, E; Millich, Antonio; Pearce, P; Potier, J P; Riche, A J; Rinolfi, Louis; Schulte, Daniel; Suberlucq, Guy; Thorndahl, L; Valentini, M; Wuensch, Walter; Zimmermann, Frank; Napoly, O; Raubenheimer, T O; Ruth, Ronald D; Syratchev, I V

1999-01-01

The CLIC study of a high energy (0.5 - 5 TeV), high luminosity (1034 - 1035 cm-2 sec-1) e± linear collider is presented. Beam acceleration using high frequency (30 GHz) normal-conducting structures operating at high accelerating fields (150 MV/m) significantly reduces the length and, in consequence, the cost of the linac. Based on new beam and linac parameters derived from a recently developed set of general scaling laws for linear colliders, the beam stability is shown to be similar to lower frequency designs in spite of the strong wake-field dependency on frequency. A new cost-effective and efficient drive beam generation scheme for RF power production by the so-called "Two Beam Acceleration (TBA)" method is described. It uses a thermionic gun and a fully-loaded normal-conducting linac operating at low frequency (937 MHz) to generate and accelerate the drive beam bunches, and RF multiplication by funnelling in compressor rings to produce the desired bunch structure. Recent 30 GHz hardware developments and ...

An Injector for the CLIC Test Facility (CTF3)

CERN Document Server

Braun, H; Rinolfi, Louis; Zhou, F; Mouton, B; Miller, R; Yeremian, A D

2000-01-01

The CLIC Test Facility (CTF3) is an intermediate step to demonstrate the technical feasibility of the key concepts of the new RF power source for CLIC. CTF3 will use electron beams with an energy range adjustable from 170 MeV (3.5 A) to 380 MeV (with low current). The injector is based on a thermionic gun followed by a classical bunching system embedded in a long solenoidal field. As an alternative, an RF photo-injector is also being studied. The beam dynamics studies on how to reach the stringent beam parameters at the exit of the injector are presented. Simulations performed with the EGUN code showed that a current of 7 A can be obtained with an emittance less than 10 mm.mrad at the gun exit. PARMELA results are presented and compared to the requested beam performance at the injector exit. Sub-Harmonic Bunchers (SHB) are foreseen, to switch the phase of the bunch trains by 180 degrees from even to odd RF buckets. Specific issues of the thermionic gun and of the SHB with fast phase switch are discussed.

An Injector for the CLIC Test Facility (CTF3)

International Nuclear Information System (INIS)

Miller, Roger H.

2001-01-01

The CLIC Test Facility (CTF3) is an intermediate step to demonstrate the technical feasibility of the key concepts of the new RF power source for CLIC. CTF3 will use electron beams with an energy range adjustable from 170 MeV (3.5 A) to 380 MeV (with low current). The injector is based on a thermionic gun followed by a classical bunching system embedded in a long solenoidal field. As an alternative, an RF photo-injector is also being studied. The beam dynamics studies on how to reach the stringent beam parameters at the exit of the injector are presented. Simulations performed with the EGUN code showed that a current of 7 A can be obtained with an emittance less than 10 mm.mrad at the gun exit. PARMELA results are presented and compared to the requested beam performance at the injector exit. Sub-Harmonic Bunchers (SHB) are foreseen, to switch the phase of the bunch trains by 180 degrees from even to odd RF buckets. Specific issues of the thermionic gun and of the SHB with fast phase switch are discussed

An injector for the CLIC test Facility (CTF3)

CERN Document Server

Braun, Hans-Heinrich; Rinolfi, L.; Zhou, F.; Mouton, B.; Miller, R.; Yeremian, D.

2008-01-01

The CLIC Test Facility (CTF3) is an intermediate step to demonstrate the technical feasibility of the key concepts of the new RF power source for CLIC. CTF3 will use electron beams with an energy range adjustable from 170 MeV (3.5 A) to 380 MeV (with low current). The injector is based on a thermionic gun followed by a classical bunching system embedded in a long solenoidal field. As an alternative, an RF photo-injector is also being studied. The beam dynamics studies on how to reach the stringent beam parameters at the exit of the injector are presented. Simulations performed with the EGUN code showed that a current of 7 A can be obtained with an emittance less than 10 mm.mrad at the gun exit. PARMELA results are presented and compared to the requested beam performance at the injector exit. Sub-Harmonic Bunchers (SHB) are foreseen, to switch the phase of the bunch trains by 180 degrees from even to odd RF buckets. Specific issues of the thermionic gun and of the SHB with fast phase switch are discussed.

Simulation of the pressure recovery time in a CLIC standard module

CERN Document Server

Costa-Pinto, P

2008-01-01

Vacuum pressure inside the CLIC accelerating structures (AS) is crucial for both beam and RF stability. Gas molecules released during RF breakdown must be evacuated from the cells of the AS before the arrival of the next train of particles. Due to its complex geometry, accurate analytical calculations are not viable. In this paper we introduce a calculation method based on the combination of analytical vacuum equations with Monte Carlo test particle simulations, implemented in a PSpice environment via the vacuum-electrical network analogy. Pressure recovery times are calculated for the main gas species released during a breakdown. The number and type of molecules used for the calculation is the result of measurements performed in the DC spark test system.

Feasibility study of multipoint based laser alignment system for CLIC

CERN Document Server

Stern, G; Mainaud-Durand, H; Piedigrossi, D; Geiger, A

2012-01-01

CLIC (Compact LInear Collider) is a study for a future electron-positron collider that would allow physicists to explore a new energy region beyond the capabilities oftoday’s particle accelerators. Alignment is one of the major challenges within the CLIC study in order to achieve the high requirement of a multi-TeV center of mass colliding beam energy range (nominal 3 TeV). To reach this energy in a realistic and cost efficient scenario all accelerator components have to be aligned with an accuracy of 10 μm over a sliding window of 200 m. The demand for a straight line reference is so far based on stretched wires coupled with Wire Positioning Sensors (WPS). These solutions are currently further developed inorder to reduce the drawbacks which are mainly given by their costs and difficult implementation. However, it should be validated through inter-comparison with a solution ideally based on a different physical principle. Therefore, a new metrological approach is proposed using a laser beam as straight lin...

Preliminary Design of an Inductive Adder for CLIC Damping Rings

CERN Document Server

Holma, J

2011-01-01

The Compact Linear Collider (CLIC) study is exploring the scheme for an electron-positron collider with high luminosity and a nominal centre-of-mass energy of 3 TeV. The CLIC damping rings will produce ultra-low emittance beam, with high bunch charge, necessary for the luminosity performance of the collider. To limit the beam emittance blow-up due to oscillations, the pulse power modulators for the damping rings kickers must provide extremely flat, high-voltage, pulses: specifications call for a 160 ns duration flattop of 12.5 kV, 250 A, with a combined ripple and droop of not more than ±0.02 %. A solid-state modulator, the inductive adder, is a very promising approach to meeting the demanding specifications; this topology allows the use of both digital and analogue modulation. To effectively use modulation techniques to achieve such low ripple and droop requires an in-depth knowledge of the behaviour of the solid-state switching components and their gate drivers, as well as a good understanding of the overa...

CLIC5 stabilizes membrane-actin filament linkages at the base of hair cell stereocilia in a molecular complex with radixin, taperin, and myosin VI.

Science.gov (United States)

Salles, Felipe T; Andrade, Leonardo R; Tanda, Soichi; Grati, M'hamed; Plona, Kathleen L; Gagnon, Leona H; Johnson, Kenneth R; Kachar, Bechara; Berryman, Mark A

2014-01-01

Chloride intracellular channel 5 protein (CLIC5) was originally isolated from microvilli in complex with actin binding proteins including ezrin, a member of the Ezrin-Radixin-Moesin (ERM) family of membrane-cytoskeletal linkers. CLIC5 concentrates at the base of hair cell stereocilia and is required for normal hearing and balance in mice, but its functional significance is poorly understood. This study investigated the role of CLIC5 in postnatal development and maintenance of hair bundles. Confocal and scanning electron microscopy of CLIC5-deficient jitterbug (jbg) mice revealed progressive fusion of stereocilia as early as postnatal day 10. Radixin (RDX), protein tyrosine phosphatase receptor Q (PTPRQ), and taperin (TPRN), deafness-associated proteins that also concentrate at the base of stereocilia, were mislocalized in fused stereocilia of jbg mice. TPRQ and RDX were dispersed even prior to stereocilia fusion. Biochemical assays showed interaction of CLIC5 with ERM proteins, TPRN, and possibly myosin VI (MYO6). In addition, CLIC5 and RDX failed to localize normally in fused stereocilia of MYO6 mutant mice. Based on these findings, we propose a model in which these proteins work together as a complex to stabilize linkages between the plasma membrane and subjacent actin cytoskeleton at the base of stereocilia. © Published 2013 Wiley Periodicals, Inc. This article is a US government work and, as such, is in the public domain in the United States of America.

A 12 kV, 1 kHz, Pulse Generator for Breakdown Studies of Samples for CLIC RF Accelerating Structures

CERN Document Server

Soares, R H; Kovermann, J; Calatroni, S; Wuensch, W

2012-01-01

Compact Linear Collider (CLIC) RF structures must be capable of sustaining high surface electric fields, in excess of 200 MV/m, with a breakdown (BD) rate below 3×10-7 breakdowns/pulse/m. Achieving such a low rate requires a detailed understanding of all the steps involved in the mechanism of breakdown. One of the fundamental studies is to investigate the statistical characteristics of the BD rate phenomenon at very low values to understand the origin of an observed dependency of the surface electric field raised to the power of 30. To acquire sufficient BD data, in a reasonable period of time, a high repetition rate pulse generator is required for an existing d.c. spark system at CERN. Following BD of the material sample the pulse generator must deliver a current pulse of several 10’s of Amperes for ~2 μs. A high repetition rate pulse generator has been designed, built and tested; this utilizes pulse forming line technology and employs MOSFET switches. This paper describes the design of the pulse generat...

CLIC-ACM: generic modular rad-hard data acquisition system based on CERN GBT versatile link

International Nuclear Information System (INIS)

Bielawski, B.; Locci, F.; Magnoni, S.

2015-01-01

CLIC is a world-wide collaboration to study the next ''terascale'' lepton collider, relying upon a very innovative concept of two-beam-acceleration. This accelerator, currently under study, will be composed of the subsequence of 21000 two-beam-modules. Each module requires more than 300 analogue and digital signals which need to be acquired and controlled in a synchronous way. CLIC-ACM (Acquisition and Control Module) is the 'generic' control and acquisition module developed to accommodate the controls of all these signals for various sub-systems and related specification in term of data bandwidth, triggering and timing synchronization. This paper describes the system architecture with respect to its radiation-tolerance, power consumption and scalability

Technologies and R&D for a High Resolution Cavity BPM for the CLIC Main Beam

CERN Document Server

Towler, J R; Soby, L; Wendt, M; Boogert, S T; Cullinan, F J; Lyapin, A

2013-01-01

The Main Beam (MB) linac of the Compact Linear Collider (CLIC) requires a beam orbit measurement system with high spatial (50 nm) and high temporal resolution (50 ns) to resolve the beam position within the 156 ns long bunch train, traveling on an energy-chirped, minimum dispersive trajectory. A 15 GHz prototype cavity BPM has been commissioned in the probe beam-line of the CTF3 CLIC Test Facility. We discuss performance and technical details of this prototype installation, including the 15 GHz analogue downconverter, the data acquisition and the control electronics and software. An R&D outlook is given for the next steps, which requires a system of 3 cavity BPMs to investigate the full resolution potential.

Integration of the PHIN RF Gun into the CLIC Test Facility

CERN Document Server

Döbert, Steffen

2006-01-01

CERN is a collaborator within the European PHIN project, a joint research activity for Photo injectors within the CARE program. A deliverable of this project is an rf Gun equipped with high quantum efficiency Cs2Te cathodes and a laser to produce the nominal beam for the CLIC Test Facility (CTF3). The nominal beam for CTF3 has an average current of 3.5 A, 1.5 GHz bunch repetition frequency and a pulse length of 1.5 ìs (2332 bunches) with quite tight stability requirements. In addition a phase shift of 180 deg is needed after each train of 140 ns for the special CLIC combination scheme. This rf Gun will be tested at CERN in fall 2006 and shall be integrated as a new injector into the CTF3 linac, replacing the existing injector consisting of a thermionic gun and a subharmonic bunching system. The paper studies the optimal integration into the machine trying to optimize transverse and longitudinal phase space of the beam while respecting the numerous constraints of the existing accelerator. The presented scheme...

CLIC main beam quadrupole active pre-alignment based on cam movers

CERN Document Server

Kemppinen, J; Leuxe, R; Mainaud Durand, H; Sandomierski, J; Sosin, M

2012-01-01

Compact Linear Collider (CLIC) is a study for a future 48 km long linear electron-positron collider in the multi TeV range. Its target luminosity can only be reached if the main beam quadrupoles (MB quads) are actively pre-aligned within 17 µm in sliding windows of 200 m with respect to a straight reference line. In addition to the positioning requirement, the pre-alignment system has to provide a rigid support for the nano-stabilization system to ensure that the first eigenfrequency is above 100 Hz. Re-adjustment based on cam movers was chosen for detailed studies to meet the stringent pre-alignment requirements. There are four different types of MB quads in CLIC. Their lengths and masses vary so that at least two types of cam movers have to be developed. The validation of the cams with less stringent space restrictions has proceeded to a test setup in 5 degrees of freedom (DOF). Prototypes of the more demanding, smaller cams have been manufactured and they are under tests in 1 DOF. This paper describes the...

Towards TeV-scale electron-positron collisions: the Compact Linear Collider (CLIC)

Science.gov (United States)

Doebert, Steffen; Sicking, Eva

2018-02-01

The Compact Linear Collider (CLIC), a future electron-positron collider at the energy frontier, has the potential to change our understanding of the universe. Proposed to follow the Large Hardron Collider (LHC) programme at CERN, it is conceived for precision measurements as well as for searches for new phenomena.

La construcción de audiencias en Internet a través de los cebos de clics

OpenAIRE

Gracia Biarge, Pablo

2018-01-01

El presente trabajo tiene como objetivo estudiar el papel de los cebos de clics en la prensa digital y su influencia en la calidad y veracidad de la información publicada. Para ello se analizarán diversos casos ilustrativos y se realizarán entrevistas a profesionales, además de contar con el apoyo teórico de autores y otros profesionales conocedores de este fenómeno. El present treball té com a objectiu estudiar el paper dels esquers de clics en la premsa digital i la seva influència en...

Permanent magnet quadrupoles for the CLIC Drive Beam decelerator

CERN Document Server

Shepherd, Ben; Collomb, Norbert

2012-01-01

STFC in collaboration with CERN has developed a new type of adjustable permanent magnet based quadrupole for the CLIC Drive Beam Decelerator. It uses vertical movement of the permanent magnets to achieve an integrated gradient range of 3.6-14.6T, which will allow it to be used for the first 60% of the decelerator line. Construction of a prototype of this magnet has begun; following this, it will be measured magnetically at CERN and Daresbury Laboratory.

Dumping the decelerated beams of CLIC

CERN Document Server

Jeanneret, Bernard

2011-01-01

The spent drive beam must be cleanly extracted and bent away from the decelerator axis at the end of each CLIC decelerator in order to leave space for injecting a fresh beam train in the next sector. Then the spent beam must be safely absorbed. A compact extraction system made of a single dipole is proposed. The spent beam is driven to a water dump located at 20m downstream of the extraction point and transversely 6m away of the axis of the main linac. An adequate spread of the beam impact map on the dump offers small temperature excursions in both the dump and its entrance window, allowing for reliable operation and a long lifetime of the system.

Tracking Performance in High Multiplicity Environment for the CLIC ILD Detector

CERN Document Server

Killenberg, M

2012-01-01

We report on the tracking efficiency and the fraction of badly reconstructed tracks in the CLIC ILD detector for high multiplicity events (tt ̄@3 TeV) with and without the presence of γγ →hadrons background. They have been studied for the silicon tracking, the TPC tracking and the so called FullLDC tacking, which combines silicon and TPC measurements.

Correction of beam-beam effects in luminosity measurement in the forward region at CLIC

CERN Document Server

Lukic, Strahinja

2013-01-01

Procedures for correcting the beam-beam effects in luminosity measurement at CLIC at 3 TeV CM energy are described and tested using Monte Carlo simulations: - Correction of the angular counting loss due to the combined Beamstrahlung and initial-state radiation (ISR) effects, based on the reconstructed velocity of the collision frame of the Bhabha scattering. - Deconvolution of the luminosity spectrum distortion due to the ISR emission. - Correction of the counting bias due to the finite calorimeter energy resolution. All procedures were tested by simulation. Bhabha events were generated using BHLUMI, and used in Guinea-PIG to simulate the outgoing momenta of Bhabha particles in the bunch collisions at CLIC. Residual uncertainties after correction are listed in a table in the conclusions. The beam-beam related systematic counting uncertainty in the luminosity peak can be reduced to the order of permille.

Correction of beam-beam effects in luminosity measurement in the forward region at CLIC

CERN Document Server

Lukic, Strahinja

2013-01-01

Procedures for correcting the beam-beam effects in luminosity measurement at CLIC at 3 TeV CM energy are described and tested using Monte Carlo simulations: -> Correction of the angular counting loss due to the combined Beamstrahlung and initial-state radiation (ISR) effects, based on the reconstructed velocity of the collision frame of the Bhabha scattering. -> Deconvolution of the luminosity spectrum distortion due to the ISR emission. -> Correction of the counting bias due to the finite calorimeter energy resolution. All procedures were tested by simulation. Bhabha events were generated using BHLUMI, and used in Guinea-PIG to simulate the outgoing momenta of Bhabha particles in the bunch collisions at CLIC. Residual uncertainties after correction are listed in a table in the conclusions. The beam-beam related systematic counting uncertainty in the luminosity peak can be reduced to the order of permille.

Structured light 3D tracking system for measuring motions in PET brain imaging

DEFF Research Database (Denmark)

Olesen, Oline Vinter; Jørgensen, Morten Rudkjær; Paulsen, Rasmus Reinhold

2010-01-01

Patient motion during scanning deteriorates image quality, especially for high resolution PET scanners. A new proposal for a 3D head tracking system for motion correction in high resolution PET brain imaging is set up and demonstrated. A prototype tracking system based on structured light with a ...

Fiducialisation and initial alignment of CLIC component with micrometric accuracy

CERN Document Server

Mainaud Durand, Helene; Buzio, Marco; Caiazza, Domenico; Catalan Lasheras, Nuria; Cherif, Ahmed; Doytchinov, Iordan Petrov; Fuchs, Jean-Frederic; Gaddi, Andrea; Galindo Munoz, Natalia; Gayde, Jean-Christophe; Kamugasa, Solomon William; Modena, Michele; Novotny, Peter; Sanz, Claude; Severino, Giordana; Russenschuck, Stephan; Tshilumba, David; Vlachakis, Vasileios; Wendt, Manfred; Zorzetti, Silvia; CERN. Geneva. ATS Department

2016-01-01

We propose a new solution to fiducialise the three major components of the CLIC collider: quadrupoles, beam-position monitors (BPM), and accelerating structures (AS). This solution is based on the use of a copper-beryllium (CuBe) wire to locate the reference position, i.e. the symmetry axes of the components (their magnetic, respectively electromagnetic centre axis), and to determine their position in the common support assembly defining a local coordinate system, with respect to the fiducials. These alignment targets will be used later to align the support assembly in the tunnel. With such a method, several accelerator components of different types, supported by a dedicated adjustment system, can be simultaneously fiducialised and pre-aligned using the same wire, enabling a micrometric accuracy with help of a 3D coordinate measurement machine (CMM). Alternative solutions based on frequency scanning interferometry (FSI) and micro-triangulation are also under development, to perform such fiducialisation and in...

A silicon pixel detector prototype for the CLIC vertex detector

CERN Multimedia

AUTHOR|(INSPIRE)INSPIRE-00714258

2017-01-01

A silicon pixel detector prototype for CLIC, currently under study for the innermost detector surrounding the collision point. The detector is made of a High-Voltage CMOS sensor (top) and a CLICpix2 readout chip (bottom) that are glued to each other. Both parts have a size of 3.3 x 4.0 $mm^2$ and consist of an array of 128 x 128 pixels of 25 x 25 $\\micro m^2$ size.

Physics potential for the measurement of sigma(H nu antinu ̄) x BR(H -->μ+μ-) at a 1.4 TeV CLIC collider

CERN Document Server

Milutinovic-Dumbelovic, Gordana; Grefe, Christian; Kacarevic, Goran; Lukic, Strahinja; Pandurovic, Mila; Roloff, Philipp Gerhard; Smiljanic, Ivan

2015-01-01

Measurements of Higgs couplings at CLIC will offer the potential for a rich precision phys- ics programme and for the search for physics beyond the Standard Model(SM). The poten- tial for measuring the SM Higgs boson decay into two muons at a 1.4 TeV CLIC collider is addressed in this paper. The study is performed using a full Geant4 detector simulation of the CLIC_ILD detector model, taking into consideration all the relevant physics and beam-induced background processes, as well as the instrumentation of the very forward region to identify high-energy electrons. In this analysis, we show that the branching ratio BR(H-->μ+μ-) times the Higgs production cross-section in W+W- fusion can be measured with 38% statistical accuracy at sqrt(s) = 1.4 TeV assuming an integrated luminosity of 1.5 ab-1 with unpolarised beams. If 80% electron beam polarisation is considered, as planned for CLIC, the statistical uncertainty of the measurement is 27%. Systematic uncertainties are negligible.

Stabilisation and precision pointing quadrupole magnets in the Compact Linear Collider (CLIC)

CERN Document Server

Janssens, Stef; Linde, Frank; van den Brand, Jo; Bertolini, Alessandro; Artoos, Kurt

This thesis describes the research done to provide stabilisation and precision positioning for the main beam quadrupole magnets of the Compact Linear Collider CLIC. The introduction describes why new particle accelerators are needed to further the knowledge of our universe and why they are linear. A proposed future accelerator is the Compact Linear Collider (CLIC) which consists of a novel two beam accelerator concept. Due to its linearity and subsequent single pass at the interaction point, this new accelerator requires a very small beam size at the interaction point, in order to increase collision effectiveness. One of the technological challenges, to obtain these small beam sizes at the interaction point, is to keep the quadrupole magnets aligned and stable to 1.5 nm integrated r.m.s. in vertical and 5 nm integrated root mean square (r.m.s.) in lateral direction. Additionally there is a proposal to create an intentional offset (max. 50 nm every 20 ms with a precision of +/- 1 nm), for several quadrupole ma...

Initial measurements on a prototype inductive adder for the CLIC kicker systems

CERN Document Server

Holma, Janne

2013-01-01

The CLIC study is exploring the scheme for an electron-positron collider with high luminosity and a nominal centre-of-mass energy of 3 TeV. The CLIC pre-damping rings and damping rings will produce, through synchrotron radiation, ultra-low emittance beam with high bunch charge. To avoid beam emittance increase, the damping ring kicker systems must provide extremely flat, high-voltage, pulses. The specifications for the extraction kickers of the DRs are particularly demanding: the flattops of the pulses must be ±12.5 kV with a combined ripple and droop of not more than ±0.02 % (±2.5 V). An inductive adder is a very promising approach to meeting the specifications. To achieve ultra-flat pulses with a fast rise time the output impedance of the inductive adder needs to be well matched to the system impedance. The parasitic circuit elements of the inductive adder have a significant effect upon the output impedance and these values are very difficult to calculate accurately analytically. To predict these paramet...

The Prototype Inductive Adder With Droop Compensation for the CLIC Kicker Systems

CERN Document Server

Holma, J

2014-01-01

The Compact Linear Collider (CLIC) study is exploring the scheme for an electron-positron collider with high luminosity and a nominal center-of-mass energy of 3 TeV. The CLIC predamping rings and damping rings (DRs) will produce, through synchrotron radiation, an ultralow emittance beam with high bunch charge. To avoid beam emittance increase, the DR kicker systems must provide extremely flat, high-voltage, pulses. The specifications for the extraction kickers of the DRs are particularly demanding: the flattops of the pulses must be ±12.5 kV with a combined ripple and droop of not more than ±0.02% (±2.5 V). An inductive adder is a very promising approach to meeting the specifications. Recently, a five-layer prototype has been built at CERN. Passive analog modulation has been applied to compensate the voltage droop, for example of the pulse capacitors. The output waveforms of the prototype inductive adder have been compared with predictions of the voltage droop and pulse shape. Conclusions are drawn concern...

The CLIC Multi-Drive Beam Scheme

CERN Document Server

Corsini, R

1998-01-01

The CLIC study of an e+ / e- linear collider in the TeV energy range is based on Two-Beam Acceleration (TBA) in which the RF power needed to accelerate the beam is extracted from high intensity relativistic electron beams, the so-called drive beams. The generation, acceleration and transport of the high-intensity drive beams in an efficient and reliable way constitute a challenging task. An overview of a potentially very effective scheme is presented. It is based on the generation of trains of short bunches, accelerated sequentially in low frequency superconducting cavities in a c.w. mode, stored in an isochronous ring and combined at high energy by funnelling before injection by sectors into the drive linac for RF power production. The various systems of the complex are discussed.

CLIC Drive Beam Position Monitor

CERN Document Server

Smith, S; Gudkov, D; Soby, L; Syratchev, I

2011-01-01

CLIC, an electron-positron linear collider proposed to probe the TeV energy scale, is based on a two-beam scheme where RF power to accelerate a high energy luminosity beam is extracted from a high current drive beam. The drive beam is efficiently generated in a long train at modest frequency and current then compressed in length and multiplied in frequency via bunch interleaving. The drive beam decelerator requires >40000 quadrupoles, each holding a beam position monitor (BPM). Though resolution requirements are modest (2 microns) these BPMs face several challenges. They must be compact and inexpensive. They must operate below waveguide cutoff to insure locality of position signals, ruling out processing at the natural 12 GHz bunch spacing frequency. Wakefields must be kept low. We find compact conventional stripline BPM with signals processed below 40 MHz can meet requirements. Choices of mechanical design, operating frequency, bandwidth, calibration and processing algorithm are presented. Calculations of wa...

High Power Test of an X-Band Slotted-IRIS Accelerator Structure at NLCTA

International Nuclear Information System (INIS)

Doebert, S.; Fandos, R.; Grudiev, A.; Heikkinen, S.; Rodriquez, J.A.; Taborelli, M.; Wuensch, W.; Adolphsen, Chris E.; Laurent, L.

2007-01-01

The CLIC study group at CERN has built two X-band HDS (hybrid damped structure) accelerating structures for high-power testing in NLCTA at SLAC. These accelerating structures are novel with respect to their rf- design and their fabrication technique. The eleven-cell constant impedance structures, one made out of copper and one out of molybdenum, are assembled from clamped high-speed milled quadrants. They feature the same heavy higher-order-mode damping as nominal CLIC structures achieved by slotted irises and radial damping waveguides for each cell. The X-band accelerators are exactly scaled versions of structures tested at 30 GHz in the CLIC test facility, CTF3. The results of the X-band tests are presented and compared to those at 30 GHz to determine frequency scaling, and are compared to the extensive copper data from the NLC structure development program to determine material dependence and make a basic validation of the HDS design

Stabilization of the Beam Intensity in the Linac at the CTF3 CLIC Test Facility

CERN Document Server

Dubrovskiy, A; Bathe, BN; Srivastava, S

2013-01-01

A new electron beam stabilization system has been introduced in CTF3 in order to open new possibilities for CLIC beam studies in ultra-stable conditions and to provide a sustainable tool to keep the beam intensity and energy at its reference values for long term operations. The stabilization system is based on a pulse-to-pulse feedback control of the electron gun to compensate intensity deviations measured at the end of the injector and at the beginning of the linac. Thereby it introduces negligible beam distortions at the end of the linac and it significantly reduces energy deviations. A self-calibration mechanism has been developed to automatically configure the feedback controller for the optimum performance. The residual intensity jitter of 0.045% of the stabilized beam was measured whereas the CLIC requirement is 0.075%.

The CLIC ILD CDR Geometry for the CDR Monte Carlo Mass Production

CERN Document Server

Muennich, A

2012-01-01

The CLIC ILD CDR detector for the Monte Carlo event simulation is described in a GEANT4 application, with some parameters available in a database and XML files. This makes it difficult to quickly “look up” interesting parameters of the detector geometry used for the simulation. This note summarises the important geometrical parameters and some details of the implemented detector components.

Fabrication Technologies of the High Gradient Accelerator Structures at 100MV/m Range

CERN Document Server

Wang, Juwen; Van Pelt, John; Yoneda, Charles; Gudkov, D; Riddone, Germana; Higo, Toshiyasu; Takatomi, Toshikazu

2010-01-01

A CERN-SLAC-KEK collaboration on high gradient X-band structure research has been established in order to demonstrate the feasibility of the CLIC baseline design for the main linac stably operating at more than 100 MV/m loaded accelerating gradient. Several prototype CLIC structures were successfully fabricated and high power tested. They operated at 105 MV/m with a breakdown rate that meets the CLIC linear collider specifications of <5×10-7/pulse/m. This paper summarizes the fabrication technologies including the mechanical design, precision machining, chemical cleaning, diffusion bonding as well as vacuum baking and all related assembly technologies. Also, the tolerances control, tuning and RF characterization will be discussed

Progress on low emittance tuning for the CLIC Damping Rings

CERN Document Server

Alabau-Gonzalvo, J; Papaphilippou, Y

2014-01-01

In the frame of the CLIC main Damping Ring a study on the sensitivity of the lattice to different sources of misalignment is presented. The minimum equilibrium emittance is simulated and analytically estimated under dipole and quadrupole rolls, and quadrupole and sextupole vertical offsets. The result of this study establishes alignment tolerances to preserve the vertical emittance below the design value (1 pmrad). Non-linear dynamics studies have been done to determine the dynamic aperture in the presence of misalignments.

Impedance effects in the CLIC damping rings

CERN Document Server

Koukovini-Platia, E; Mounet, N; Rumolo, G; Salvant, B

2011-01-01

Due to the unprecedented brilliance of the beams, the performance of the Compact Linear Collider (CLIC) damping rings (DR) is affected by collective effects. Single bunch instability thresholds based on a broad-band resonator model and the associated coherent tune shifts have been evaluated with the HEADTAIL code. Simulations performed for positive and negative values of chromaticity showed that higher order bunch modes can be potentially dangerous for the beam stability. This study also includes the effects of high frequency resistive wall impedance due to different coatings applied on the chambers of the wigglers for e-cloud mitigation and/or ultra-low vacuum pressure. The impact of the resistive wall wake fields on the transverse impedance budget is finally discussed.

Physics potential for the measurement of σ (Hνν) × BR(H → μ+μ−) at a 1.4 TeV CLIC collider

CERN Document Server

Milutinović-Dumbelović, G; Grefe, C; Lukić, S; Pandurović, M; Roloff, P

2014-01-01

The potential for the measurement of the branching ratio of the Standard Model-like Higgs boson decay into a μ+μ− pair at 1.4 TeV CLIC is analysed. The study is performed using the fully simulated CLIC_ILD detector concept, taking into consideration all the relevant physics and the beam-induced backgrounds. Despite the very low branching ratio of the H → μ+μ− decay, we show that the product of the branching ratio times the Higgs production cross section can be measured with a statistical uncertainty of 38 %, assuming an integrated luminosity of 1.5 ab−1 collected in five years of the detector operation at the 1.4 TeV CLIC with unpolarised beams. With polarised beams (+80 %, -30 %), the statistical uncertainty is better than 25%

A damped and detuned accelerating structure for the main linacs of the compact linear collider

CERN Document Server

Khan, V

2011-01-01

Linear colliders are an option for lepton collision at several TeV. The Compact Linear Collider (CLIC) aims at electron and positron collisions at a centre of mass energy of 3 TeV. In CLIC, the main accelerating structures are designed to operate at an X-band frequency of 12 GHz with an accelerating gradient of 100 MV/m. Two significant issues in linear accelerators that can prevent high gradient being achieved are electrical breakdown and wakefields. The baseline design for the CLIC main linacs relies on a small aperture size to reduce the breakdown probability and a strong damping scheme to suppress the wakefields. The strong damping scheme may have a higher possibility of electrical breakdown. In this thesis an alternative design for the main accelerating structures of CLIC is studied and various aspects of this design are discussed. This design is known as a Damped and Detuned Structure (DDS) which relies on moderate damping and strong detuning of the higher order modes (HOMs). The broad idea of DDS is ba...

Commissioning status of the decelerator test beam line in CTF3

CERN Document Server

Adli, E; Lillestol, R; Olvegaard, M; Syratchev, I; Carrillo, D; Toral, F; Faus-Golfe, A; Garcia-Garrigos, J J; Kubyshin, Y; Montoro, G

2010-01-01

The CLIC Test Facility (CTF3) at CERN was constructed by the CTF3 collaboration to study the feasibility of the concepts for a compact linear collider. The test beam line (TBL) recently added to the CTF3 machine was designed to study the CLIC decelerator beam dynamics and 12 GHz power production. The beam line consists of a FODO lattice with high precision BPM’s and quadrupoles on movers for precise beam alignment. A total of 16 Power Extraction and Transfer Structures (PETS) will be installed in between the quadrupoles to extract 12 GHz power from the drive beam provided by the CTF3 machine. The CTF3 drive beam with a bunch-train length of 140 ns, 12 GHz bunch repetition frequency and an average current over the train of up to 28 A will be injected into the test beam line. Each PETS structure will produce 135 MW of 12 GHz power at nominal current. The beam will have lost more than 50 % of its initial energy of 150 MeV at the end of the beam line and will contain particles with energies between 65 MeV and 1...

The Baseline Positron Production and Capture Scheme for CLIC

CERN Document Server

Dadoun, Olivier; Lepercq, Pierre; Poirier, Freddy; Variola, Alessandro; Chehab, Robert; Rinolfi, Louis; Vivoli, Alessandro; Strakhovenko, Vladimir; Xu, Chengai

2010-01-01

The CLIC study considers the hybrid source using channeling as the baseline for unpolarised positron production. The hybrid source uses a few GeV electron beam impinging on a tungsten crystal target. With the crystal oriented on its axis it results an intense relatively low energy photon beam. The later is then impinging on an amorphous tungsten target producing positrons by e+e− pair creation. Downstream the amorphous target, a capture section based on an adiabatic matching device followed by a 2 GHz Pre- Injector Linac focuses and accelerates the positron beam up to around 200 MeV

3D quantification of soil structure and functioning based on PET and CT scanning techniques

DEFF Research Database (Denmark)

Garbout, Amin

This thesis explores the potential of PET and CT scanning techniques to quantify and visualize soil structure, root development, and soil/plant interactions. At the investigated scale, these non-invasive and nondestructive techniques have some obvious advantages compared with most other techniques....... The processed measurements show some expected and a few unexpected effects (or lack of effects) on different characteristics of soil structure. The combination of CT and PET scanning in an air plant soil controller system revealed some very interesting research possibilities. Interactions between soil structure...

Neuronal pathology in deep grey matter structures: a multimodal imaging analysis combining PET and MRI

Energy Technology Data Exchange (ETDEWEB)

Bosque-Freeman, L.; Leroy, C.; Galanaud, D.; Sureau, F.; Assouad, R.; Tourbah, A.; Papeix, C.; Comtat, C.; Trebossen, R.; Lubetzki, C.; Delforge, J.; Bottlaender, M.; Stankoff, B. [Serv. Hosp. Frederic Joliot, Orsay (France)

2009-07-01

Objective: To assess neuronal damage in deep gray matter structures by positron emission tomography (PET) using [{sup 11}C]-flumazenil (FMZ), a specific central benzodiazepine receptor antagonist, and [{sup 18}F]-fluorodeoxyglucose (FDG), which reflects neuronal metabolism. To compare results obtained by PET and those with multimodal magnetic resonance imaging (MRI). Background: It is now accepted that neuronal injury plays a crucial role in the occurrence and progression of neurological disability in multiple sclerosis (MS). To date, available MRI techniques do not specifically assess neuronal damage, but early abnormalities, such as iron deposition or atrophy, have been described in deep gray matter structures. Whether those MRI modifications correspond to neuronal damage remains to be further investigated. Materials and methods: Nine healthy volunteers were compared to 10 progressive and 9 relapsing remitting (RR) MS patients. Each subject performed two PET examinations with [{sup 11}C]-FMZ and [{sup 18}F]-FDG, on a high resolution research tomograph dedicated to brain imaging (Siemens Medical Solution, spatial resolution of 2.5 mm). Deep gray matter regions were manually segmented on T1-weighted MR images with the mutual information algorithm (www.brainvisa.info), and co-registered with PET images. A multimodal MRI including T1 pre and post gadolinium, T2-proton density sequences, magnetization transfer, diffusion tensor, and protonic spectroscopy was also performed for each subject. Results: On PET with [{sup 11}C]-FMZ, there was a pronounced decrease in receptor density for RR patients in all deep gray matter structures investigated, whereas the density was unchanged or even increased in the same regions for progressive patients. Whether the different patterns between RR and progressive patients reflect distinct pathogenic mechanisms is currently investigated by comparing PET and multimodal MRI results. Conclusion: Combination of PET and multimodal MR imaging

Recent results with HV-CMOS and planar sensors for the CLIC vertex detector

CERN Document Server

AUTHOR|(SzGeCERN)734627

2017-01-01

The physics aims for the future multi-TeV e+e- Compact Linear Collider (CLIC) impose high precision requirements on the vertex detector which has to match the experimental conditions, such as the time structure of the collisions and the presence of beam-induced backgrounds. The principal challenges are: a point resolution of 3μm, 10 ns time stamping capabilities, low mass (⇠0.2% X0 per layer), low power dissipation and pulsed power operation. Recent results of test beam measurements and GEANT4 simulations for assemblies with Timepix3 ASICs and thin active-edge sensors are presented. The 65 nm CLICpix readout ASIC with 25μm pitch was bump bonded to planar silicon sensors and also capacitively coupled through a thin layer of glue to active HV-CMOS sensors. Test beam results for these two hybridisation concepts are presented.

Electron Cloud Build Up and Instability in the CLIC Damping Rings

CERN Document Server

Rumolo, G; Papaphilippou, Y

2008-01-01

Electron cloud can be formed in the CLIC positron damping ring and cause intolerable tune shift and beam instability. Build up simulations with the Faktor2 code, developed at CERN, have been done to predict the cloud formation in the arcs and wigglers of the damping rings. HEADTAIL simulations have been used to study the effect of this electron cloud on the beam and assess the thresholds above which the electron cloud instability would set in.

A Vertex and Tracking Detector System for CLIC

CERN Document Server

AUTHOR|(SzGeCERN)718101

2017-01-01

The physics aims at the proposed future CLIC high-energy linear $e^+e^−$ collider pose challenging demands on the performance of the detector system. In particular the vertex and tracking detectors have to combine precision measurements with robustness against the expected high rates of beam-induced backgrounds. The requirements include ultra-low mass, facilitated by power pulsing and air cooling in the vertex-detector region, small cell sizes and precision hit timing at the few-ns level. A detector concept meeting these requirements has been developed and an integrated R&D program addressing the challenges is progressing in the areas of ultra-thin sensors and readout ASICs, interconnect technology, mechanical integration and cooling.

Ring Coils on the Endcap Yoke of a CLIC Detector

CERN Document Server

Gerwig, H

2011-01-01

Ring coils on the endcap return yoke can be useful in several ways. Depending on their size and the current chosen, they may either be used to reduce the fringe-field outside the return yoke of a detector, or to reduce considerably the thickness of the endcap yoke. The main focus of this note is the analysis of the ring coils, with the aim to reduce the overall length of the CLIC_ILD detector. In addition, some results concerning the fringe field in the vicinity of the detector are shown.

Simultaneous evaluation of brain tumour metabolism, structure and blood volume using [18F]-fluoroethyltyrosine (FET) PET/MRI

DEFF Research Database (Denmark)

Henriksen, Otto M.; Larsen, Vibeke A; Muhic, Aida

2016-01-01

PURPOSE: Both [(18)F]-fluoroethyltyrosine (FET) PET and blood volume (BV) MRI supplement routine T1-weighted contrast-enhanced MRI in gliomas, but whether the two modalities provide identical or complementary information is unresolved. The aims of the study were to investigate the feasibility...... of simultaneous structural MRI, BV MRI and FET PET of gliomas using an integrated PET/MRI scanner and to assess the spatial and quantitative agreement in tumour imaging between BV MRI and FET PET. METHODS: A total of 32 glioma patients underwent a 20-min static simultaneous PET/MRI acquisition on a Siemens m......MR system 20 min after injection of 200 MBq FET. The MRI protocol included standard structural MRI and dynamic susceptibility contrast (DSC) imaging for BV measurements. Maximal relative tumour FET uptake (TBRmax) and BV (rBVmax), and Dice coefficients were calculated to assess the quantitative and spatial...

RGA studies on aluminium chambers for transport line-2 of CLIC facility at CERN

International Nuclear Information System (INIS)

Kumar, K.V.A.N.P.S.; Yadav, Praveen Kumar; Sindal, B.K.; Tiwari, S.K.; Tripti, B.; Shukla, S.K.

2009-01-01

The Aluminium Chambers for Transport Line-2 (TL-2) of CLIC (Compact Linear Collider) facility were developed by RRCAT, Indore under the CERN-DAE collaboration work. The ultimate vacuum required for these chambers is in 10 -10 mbar range. The design and fabrication of the chambers were done at Workshop-A, RRCAT, Indore. Ultra High Vacuum (UHV) Section at RRCAT, Indore was involved in qualifying tests of these chambers for their ultimate vacuum testing and the residual gas spectrum studies as per CERN requirements. The UHV testing part was established and the RGA studies were conducted using Residual Gas Analyser (RGA, 1-100 AMU range, Make: Spectra/MKS, USA). The RGAs were used for vacuum diagnostics like checking for leaks and the vacuum quality in the chambers. Using the RGA, we could also observe out the pumping speed behaviour of a UHV Gauge (Varian UHV-24 type) and the retention-cum-evaluation of captured gases by Sputter Ion Pump was also studied. In this paper, these experiences are reported during ultimate testing of TL-2 chambers for CLIC facility. (author)

Design of the Injection and extraction system and related machine protection for the Clic Damping Rings

CERN Document Server

Apsimon, Robert; Barnes, Mike; Borburgh, Jan; Goddard, Brennan; Papaphilippou, Yannis; Uythoven, Jan

2014-01-01

Linear machines such as CLIC have relatively low rates of collision between bunches compared to their circular counterparts. In order to achieve the required luminosity, a very small spot size is envisaged at the interaction point, thus a low emittance beam is needed. Damping rings are essential for producing the low emittances needed for the CLIC main beam. It is crucial that the beams are injected and extracted from the damping rings in a stable and repeatable fashion to minimise emittance blow-up and beam jitter at the interaction point; both of these effects will deteriorate the luminosity at the interaction point. In this paper, the parameters and constraints of the injection and extraction systems are considered and the design of these systems is optimised within this parameter space. Related machine protection is considered in order to prevent damage from potential failure modes of the injection and extraction systems.

Status of a study of stabilization and fine positioning of CLIC quadrupoles to the nanometre level

CERN Document Server

Artoos, K; Esposito, M; Fernandez Carmona, P; Guinchard, M; Hauviller, C; Janssens, S; Kuzmin, A; Leuxe, R; Moron Ballester, R

2011-01-01

Mechanical stability to the nanometre and below is required for the Compact Linear Collider (CLIC) quadrupoles to frequencies as low as 1 Hz. An active stabilization and positioning system based on very stiff piezo electric actuators and inertial reference masses is under study for the Main Beam Quadrupoles (MBQ). The stiff support was selected for robustness against direct forces and for the option of incrementally repositioning the magnet with nanometre resolution. The technical feasibility was demonstrated by a representative test mass being stabilized and repositioned to the required level in the vertical and lateral direction. Technical issues were identified and the development programme of the support, sensors, and controller was continued to increase the performance, integrate the system in the overall controller, adapt to the accelerator environment, and reduce costs. The improvements are implemented in models, test benches, and design of the first stabilized prototype CLIC magnet. The characterizati...

Transparent, flexible surface enhanced Raman scattering substrates based on Ag-coated structured PET (polyethylene terephthalate) for in-situ detection

International Nuclear Information System (INIS)

Zuo, Zewen; Zhu, Kai; Gu, Chuan; Wen, Yibing; Cui, Guanglei; Qu, Jun

2016-01-01

Highlights: • Transparent, flexible SERS substrates were prepared using techniques compatible with well-established silicon device technologies. • The SERS substrates exhibit high sensitivity and good reproducibility. • The high performance is related with the quasi-three-dimensional structure of the PET. • In-situ detection of analyte on irregular objects was achieved by this SERS substrate. - Abstract: Transparent, flexible surface-enhanced Raman scattering (SERS) substrates were fabricated by metalization of structured polyethylene terephthalate (PET) sheets. The resultant Ag-coated structured PET SERS substrates were revealed to be highly sensitive with good reproducibility and stability, an enhancement factor of 3 × 10 6 was acquired, which can be attributed mainly to the presence of plentiful multiple-type hot spots within the quasi-three-dimensional surface of the structured PET obtained by oxygen plasma etching. In addition, detections of model molecules on fruit skin were also carried out, demonstrating the great potential of the Ag-coated structured PET in in-situ detection of analyte on irregular objects. Importantly, the technique used for the preparation of such substrate is completely compatible with well-established silicon device technologies, and large-area fabrication with low cost can be readily realized.

Transparent, flexible surface enhanced Raman scattering substrates based on Ag-coated structured PET (polyethylene terephthalate) for in-situ detection

Energy Technology Data Exchange (ETDEWEB)

Zuo, Zewen, E-mail: zuozewen@mail.ahnu.edu.cn; Zhu, Kai; Gu, Chuan; Wen, Yibing; Cui, Guanglei; Qu, Jun

2016-08-30

Highlights: • Transparent, flexible SERS substrates were prepared using techniques compatible with well-established silicon device technologies. • The SERS substrates exhibit high sensitivity and good reproducibility. • The high performance is related with the quasi-three-dimensional structure of the PET. • In-situ detection of analyte on irregular objects was achieved by this SERS substrate. - Abstract: Transparent, flexible surface-enhanced Raman scattering (SERS) substrates were fabricated by metalization of structured polyethylene terephthalate (PET) sheets. The resultant Ag-coated structured PET SERS substrates were revealed to be highly sensitive with good reproducibility and stability, an enhancement factor of 3 × 10{sup 6} was acquired, which can be attributed mainly to the presence of plentiful multiple-type hot spots within the quasi-three-dimensional surface of the structured PET obtained by oxygen plasma etching. In addition, detections of model molecules on fruit skin were also carried out, demonstrating the great potential of the Ag-coated structured PET in in-situ detection of analyte on irregular objects. Importantly, the technique used for the preparation of such substrate is completely compatible with well-established silicon device technologies, and large-area fabrication with low cost can be readily realized.

Two frequency beam-loading compensation in the drive-beam accelerator of the CLIC Test Facility

CERN Document Server

Braun, Hans Heinrich

1999-01-01

The CLIC Test Facility (CTF) is a prototype two-beam accelerator, in which a high-current "drive beam" is used to generate the RF power for the main-beam accelerator. The drive-beam accelerator consists of two S-band structures which accelerate a bunch train with a total charge of 500 nC. The substantial beam loading is compensated by operating the two accelerating structures at 7.81 MHz above and below the bunch repetition frequency, respectively. This introduces a change of RF phase from bunch to bunch, which leads, together with off-crest injection into the accelerator, to an approximate compensation of the beam loading. Due to the sinusoidal time-dependency of the RF field, an energy spread of about 7% remains in the bunch train. A set of idler cavities has been installed to reduce this residual energy spread further. In this paper, the considerations that motivated the choice of the parameters of the beam-loading compensation system, together with the experimental results, are presented.

X-ray crystal structure of the passenger domain of plasmid encoded toxin(Pet), an autotransporter enterotoxin from enteroaggregative Escherichia coli (EAEC)

Energy Technology Data Exchange (ETDEWEB)

Domingo Meza-Aguilar, J. [Departamento de Salud Pública Facultad de Medicina UNAM, Ciudad Universitaria Coyoacán 04510, D.F. (Mexico); Laboratorio de Patogenicidad Bacteriana, Unidad de Hemato Oncología e Investigación, Hospital Infantil de México Federico Gómez 06720, D.F. (Mexico); Fromme, Petra [Department of Chemistry and Biochemistry, Arizona State University, Physical Sciences BLDG D-102, Tempe, AZ 85287 (United States); Torres-Larios, Alfredo [Instituto de Fisiología Celular UNAM, Ciudad Universitaria Coyoacán 04510, D.F. (Mexico); Mendoza-Hernández, Guillermo [Instituto de Química UNAM, Ciudad Universitaria Coyoacán 04510, D.F (Mexico); Hernandez-Chiñas, Ulises [Departamento de Salud Pública Facultad de Medicina UNAM, Ciudad Universitaria Coyoacán 04510, D.F. (Mexico); Laboratorio de Patogenicidad Bacteriana, Unidad de Hemato Oncología e Investigación, Hospital Infantil de México Federico Gómez 06720, D.F. (Mexico); Arreguin-Espinosa de los Monteros, Roberto A. [Instituto de Química UNAM, Ciudad Universitaria Coyoacán 04510, D.F (Mexico); and others

2014-03-07

Highlights: • X-ray crystal structure of the passenger domain of Plasmid encoded toxin at 2.3 Å. • Structural differences between Pet passenger domain and EspP protein are described. • High flexibility of the C-terminal beta helix is structurally assigned. - Abstract: Autotransporters (ATs) represent a superfamily of proteins produced by a variety of pathogenic bacteria, which include the pathogenic groups of Escherichia coli (E. coli) associated with gastrointestinal and urinary tract infections. We present the first X-ray structure of the passenger domain from the Plasmid-encoded toxin (Pet) a 100 kDa protein at 2.3 Å resolution which is a cause of acute diarrhea in both developing and industrialized countries. Pet is a cytoskeleton-altering toxin that induces loss of actin stress fibers. While Pet (pdb code: 4OM9) shows only a sequence identity of 50% compared to the closest related protein sequence, extracellular serine protease plasmid (EspP) the structural features of both proteins are conserved. A closer structural look reveals that Pet contains a β-pleaded sheet at the sequence region of residues 181–190, the corresponding structural domain in EspP consists of a coiled loop. Secondary, the Pet passenger domain features a more pronounced beta sheet between residues 135 and 143 compared to the structure of EspP.

Identification of Potent Chloride Intracellular Channel Protein 1 Inhibitors from Traditional Chinese Medicine through Structure-Based Virtual Screening and Molecular Dynamics Analysis

Directory of Open Access Journals (Sweden)

Wei Wang

2017-01-01

Full Text Available Chloride intracellular channel 1 (CLIC1 is involved in the development of most aggressive human tumors, including gastric, colon, lung, liver, and glioblastoma cancers. It has become an attractive new therapeutic target for several types of cancer. In this work, we aim to identify natural products as potent CLIC1 inhibitors from Traditional Chinese Medicine (TCM database using structure-based virtual screening and molecular dynamics (MD simulation. First, structure-based docking was employed to screen the refined TCM database and the top 500 TCM compounds were obtained and reranked by X-Score. Then, 30 potent hits were achieved from the top 500 TCM compounds using cluster and ligand-protein interaction analysis. Finally, MD simulation was employed to validate the stability of interactions between each hit and CLIC1 protein from docking simulation, and Molecular Mechanics/Generalized Born Surface Area (MM-GBSA analysis was used to refine the virtual hits. Six TCM compounds with top MM-GBSA scores and ideal-binding models were confirmed as the final hits. Our study provides information about the interaction between TCM compounds and CLIC1 protein, which may be helpful for further experimental investigations. In addition, the top 6 natural products structural scaffolds could serve as building blocks in designing drug-like molecules for CLIC1 inhibition.

Imaging with PET system

International Nuclear Information System (INIS)

Das, B.K.; Noreen Norfaraheen Lee Abdullah

2012-01-01

PET deals with biochemistry and metabolic changes that occur at molecular level. Hence, PET differs fundamentally from other imaging modalities. CT imaging is based on tissue density, whereas MRI conveys anatomic information based on proton density and proton relaxation dynamics. CT and MRI are useful in clinical diagnosis only when disease process has caused significant anatomic alterations. However, in most disease conditions chemical changes precede anatomic changes, that can be detected by PET technology. Thus, PET can provide earliest and unique information about ongoing disease process long before anatomic or structural changes take place. There is no other modality available at present that can replace PET technology. Although PET produces cross-sectional images like that obtained in MRI or CT, they represent circulation, function and metabolism, and not anatomic structure. PET is extremely sensitive measuring quantitatively concentration of tracers in nano to pico-molar range. Thus, PET enables merger of biochemistry and biology in medicine giving birth to molecular medicine that focuses on identifying the molecular errors of disease leading to developing molecular corrections including gene therapy. Molecular imaging with PET has been playing a role in examining the biological nature of a disease condition and its characterization to guide selection and evaluation of treatment. (author)

Clinical Computer Systems Survey (CLICS): learning about health information technology (HIT) in its context of use.

Science.gov (United States)

Lichtner, Valentina; Cornford, Tony; Klecun, Ela

2013-01-01

Successful health information technology (HIT) implementations need to be informed on the context of use and on users' attitudes. To this end, we developed the CLinical Computer Systems Survey (CLICS) instrument. CLICS reflects a socio-technical view of HIT adoption, and is designed to encompass all members of the clinical team. We used the survey in a large English hospital as part of its internal evaluation of the implementation of an electronic patient record system (EPR). The survey revealed extent and type of use of the EPR; how it related to and integrated with other existing systems; and people's views on its use, usability and emergent safety issues. Significantly, participants really appreciated 'being asked'. They also reminded us of the wider range of administrative roles engaged with EPR. This observation reveals pertinent questions as to our understanding of the boundaries between administrative tasks and clinical medicine - what we propose as the field of 'administrative medicine'.

Accelerator and Technical Sector Seminar: Mechanical stabilization and positioning of CLIC quadrupoles with sub-nanometre resolution

CERN Multimedia

2011-01-01

Thursday 24 November 2010 Accelerator and Technical Sector Seminar at 14:15  -  BE Auditorium, bldg. 6 (Meyrin) – please note unusual place Mechanical stabilization and positioning of CLIC quadrupoles with sub-nanometre resolution Stef Janssens /EN-MME Abstract: To reach the required luminosity at the CLIC interaction point, about 4000 quadrupoles are needed to obtain a vertical beam size of 1 nm at the interaction point. The mechanical jitter of the quadrupole magnets will result in an emittance growth. An active vibration isolation system is required to reduce vibrations from the ground and from external forces to about 1.5 nm integrated root mean square (r.m.s.) vertical displacement at 1 Hz. A short overview of vibration damping and isolation strategies will be presented as well as a comparison of existing systems. The unprecedented resolution requirements and the instruments enabling these measurements will be discussed. The vibration sources from which the magnets need to...

Study of a 5-Tesla large aperture coil for the CLIC detector

CERN Document Server

Cure, B

2011-01-01

The present design of a CLIC detector foresees a large solenoid magnet with a 6 m aperture and a magnetic induction of 5 T at the interaction point. This can be achieved by a thin superconducting coil. This report gives the typical main parameters of such a coil and presents the feasibility based on and compared with the CMS and Atlas solenoid coil designs, indicating the limits on the conductor and the identified R&D prospects.

Test-beam measurements and simulation studies of thin pixel sensors for the CLIC vertex detector

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00574329; Dannheim, Dominik

The multi-$TeV$ $e^{+}e^{-}$ Compact Linear Collider (CLIC) is one of the options for a future high-energy collider for the post-LHC era. It would allow for searches of new physics and simultaneously offer the possibility for precision measurements of standard model processes. The physics goals and experimental conditions at CLIC set high precision requirements on the vertex detector made of pixel detectors: a high pointing resolution of 3 $\\mu m$, very low mass of 0.2% $X_{0}$ per layer, 10 ns time stamping capability and low power dissipation of 50 mW/$cm^{2}$ compatible with air-flow cooling. In this thesis, hybrid assemblies with thin active-edge planar sensors are characterised through calibrations, laboratory and test-beam measurements. Prototypes containing 50 $\\mu m$ to 150 $\\mu m$ thin planar silicon sensors bump-bonded to Timepix3 readout ASICs with 55 $\\mu m$ pitch are characterised in test beams at the CERN SPS in view of their detection efficiency and single-point resolution. A digitiser for AllP...

Measurements on Prototype Inductive Adders with Ultra-Flat-Top Output Pulses for CLIC DR Kickers

CERN Document Server

Holma, J; Belver-Aguilar, C

2014-01-01

The CLIC study is investigating the technical feasibility of an electron-positron collider with high luminosity and a nominal centre-of-mass energy of 3 TeV. The CLIC pre-damping rings and damping rings (DRs) will produce ultra-low emittance beam with high bunch charge. To avoid beam emittance increase, the DR kicker systems must provide extremely flat, high-voltage, pulses. The specifications for the DR extraction kickers call for a 160 ns duration flat-top pulses of ±12.5 kV, 250 A, with a combined ripple and droop of not more than ±0.02 % (±2.5 V). An inductive adder is a very promising approach to meeting the specifications because this topology allows the use of both passive and analogue modulation methods to adjust the output waveform. Recently, two five-layer, 3.5 kV, prototype inductive adders have been built at CERN. The first of these has been used to test the passive and active analogue modulation methods to compensate voltage droop and ripple of the output pulses. Pulse waveforms have been reco...

Separation of hadronic W and Z decays in the CLIC_ILD and the CLICdet detector models at 1.4 and 3TeV

CERN Document Server

AUTHOR|(SzGeCERN)793139; Roloff, Philipp Gerhard; Strom, Lars Rickard; Weber, Matthias Artur

2017-01-01

A study of the W and Z separation was performed for the CLIC_ILD and the CLICdet detector models for the proposed Compact Linear Collider (CLIC). Comparisons were done for fully-hadronic WW and ZZ events at the collision energies of 1.4 and 3 TeV. Particle flow objects are reconstructed using a full simulation of the events including relevant beam-induced background processes. Several different collections of particles, with varying level of background suppression, were compared for each of the detector models and optimal jet clustering parameters were found in each case, resulting in the best separation of the W and Z mass peaks. The CLICdet detector model performs similar to CLIC_ILD with an achieved jet mass separation of around 1.6 $\\sigma$ at 1.4 TeV and 1.3 $\\sigma$ at 3 TeV. For both detector models we achieve a better separation at 1.4 TeV when comparing dijet masses rather than large-R jet masses. At 3 TeV jets with a radius around R=0.5 perform similarly well as dijets.

Direct Patlak Reconstruction From Dynamic PET Data Using the Kernel Method With MRI Information Based on Structural Similarity.

Science.gov (United States)

Gong, Kuang; Cheng-Liao, Jinxiu; Wang, Guobao; Chen, Kevin T; Catana, Ciprian; Qi, Jinyi

2018-04-01

Positron emission tomography (PET) is a functional imaging modality widely used in oncology, cardiology, and neuroscience. It is highly sensitive, but suffers from relatively poor spatial resolution, as compared with anatomical imaging modalities, such as magnetic resonance imaging (MRI). With the recent development of combined PET/MR systems, we can improve the PET image quality by incorporating MR information into image reconstruction. Previously, kernel learning has been successfully embedded into static and dynamic PET image reconstruction using either PET temporal or MRI information. Here, we combine both PET temporal and MRI information adaptively to improve the quality of direct Patlak reconstruction. We examined different approaches to combine the PET and MRI information in kernel learning to address the issue of potential mismatches between MRI and PET signals. Computer simulations and hybrid real-patient data acquired on a simultaneous PET/MR scanner were used to evaluate the proposed methods. Results show that the method that combines PET temporal information and MRI spatial information adaptively based on the structure similarity index has the best performance in terms of noise reduction and resolution improvement.

Comparative Study of the Tuning Performances of the Nominal and Long L* CLIC Final Focus System at √s = 380 GeV

CERN Document Server

Plassard, F; Marin, E; Tomás, R

2017-01-01

Mitigation of static imperfections for emittance preservation is one of the most important and challenging tasks faced by the Compact Linear Collider (CLIC) beam delivery system. A simulation campaign has been performed to recover the nominal luminosity by means of different alignment procedures. The state of the art of the tuning studies is drawn up. Comparative studies of the tuning performances and a tuning-based final focus system design optimization for two L options are presented. The effectiveness of the tuning techniques applied to these different lattices will be decisive for the final layout of the CLIC final focus system at √s = 380 GeV.

Study of an hybrid positron source using channeling for CLIC

CERN Document Server

Dadoun, O; Chehab, R; Poirier, F; Rinolfi, L; Strakhovenko, V; Variola, A; Vivoli, A

2009-01-01

The CLIC study considers the hybrid source using channeling as the baseline for positron production. The hybrid source uses a few GeV electron beam impinging on a crystal tungsten radiator. With the tungsten crystal oriented on its axis it results an intense, relatively low energy photon beam due mainly to channeling radiation. Those photons are then impinging on an amorphous tungsten target producing positrons by e+e− pair creation. In this note the optimization of the positron yield and the peak energy deposition density in the amorphous target are studied according to the distance between the crystal and the amorphous targets, the primary electron energy and the amorphous target thickness.

Fluka and thermo-mechanical studies for the CLIC main dump

CERN Document Server

Mereghetti, Alessio; Vlachoudis, Vasilis

2011-01-01

In order to best cope with the challenge of absorbing the multi-MW beam, a water beam dump at the end of the CLIC post-collision line has been proposed. The design of the dump for the Conceptual Design Report (CDR) was checked against with a set of FLUKA Monte Carlo simulations, for the estimation of the peak and total power absorbed by the water and the vessel. Fluence spectra of escaping particles and activation rates of radio-nuclides were computed as well. Finally, the thermal transient behavior of the water bath and a thermo-mechanical analysis of the preliminary design of the window were done.

Cam Mover Alignment System positioning with the Wire Positioning with the Wire Position Sensor Feedback for CLIC

CERN Document Server

AUTHOR|(CDS)2077936; Mainaud Durand, Helene; Kostka, Z.S.

2016-01-01

Compact Linear Collider (CLIC) is a study of an electron-positron collider with nominal energy of 3 TeV and luminosity of 2 ∙ 1034 cm-2s-1. The luminosity goal leads to stringent alignment requirements for single quadrupole magnets. Vertical and lateral offset deviations with regards to a given orbit reference in both ends of a quadrupole shall be below 1 μm and quadrupole roll deviation shall be below 100 μrad. Translation in the direction of particle beam is not controlled but mechanically locked. A parallel kinematic platform based on cam movers was chosen as system for detailed studies. Earlier studies have shown that cam movers can reach the CLIC requirements through an iterative process. The paper presents new modular off-the-shelf control electronics and software including three optional positioning algorithms based on iterations as well as a more advanced algorithm which can reach target position in one movement. The advanced algorithm reads wire position sensors (WPS), calculates quadrupole orien...

Effect of gamma radiation on the structural and optical properties of Polyethyleneterephthalate (PET) polymer

International Nuclear Information System (INIS)

Siddhartha; Aarya, Suveda; Dev, Kapil; Raghuvanshi, Suresh Kumar; Krishna, J.B.M.; Wahab, M.A.

2012-01-01

Effect of 1.25 MeV gamma radiation on the structural and optical properties of virgin and gamma irradiated (0–2000 kGy) Polyethyleneterephthalate (PET) polymer samples are analyzed using powder X-ray diffractometer and UV–vis spectrophotometer. Diffraction pattern of PET polymer indicates the semi-crystalline in nature whereas the crystallinity increases with increasing dose of irradiation. The remarkable variation in crystallite size is also observed. The absorption and activation energy increase and the optical band gap (E g ) decreases with increasing dose in UV–vis studies. The existence of the maximum absorption, their shifting and broadening due to gamma irradiation in PET polymer are also discussed. - Highlights: ► PET is the transparent polymer and semi- crystalline. ► Crystallinity increases with increasing dose of irradiation of polymer. ► The remarkable variation in crystallite sizes was also observed in polymer. ► The absorption and activation energy increase and where as the optical band gap (E g ) decrease with increasing dose.

Prospects for the measurement of the Higgs Yukawa couplings to b and c quarks, and muons at CLIC

Czech Academy of Sciences Publication Activity Database

Grefe, C.; Laštovička, Tomáš; Strube, J.

2013-01-01

Roč. 73, č. 2 (2013), s. 1-7 ISSN 1434-6044 Institutional support: RVO:68378271 Keywords : Higgs * branching * ratio * Yukawa * couplings * quarks * muons * CLIC * inear collider Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 5.436, year: 2013

Dedicated brain PET system of PET/MR for brain research

International Nuclear Information System (INIS)

Cheng, Li; Liu, Yaqiang; Ma, Tianyu; Wang, Shi; Wei, Qingyang; Xu, Tianpeng

2015-01-01

This work is to replace PET ring in human brain PET/MR system with a dedicated wearable PET insert, aimed at improving both patient feasibility and system performance for brain imaging. The designed PET/MR system includes two parts: the inside parts, including a radio frequency (RF) coil and PET ring, are mounted on patient’s head, and the outside part, a MR imager, is dependent of patient. The RF coil is the innermost layer, surrounded by an outer PET-ring layer. They are supported by a MRcompatible structure. And both RF coil and PET detectors are placed inside a standard clinical 3-T MR imager. From the design of the system we can infer that some advantages can be achieved. First, high sensitivity will be achieved with the same amount crystals as the PET ring is more close to region-of-interest area, at a reduced cost. Second, by using a 2-layer depth of interaction (DOI) detector, the parallax effect can be minimized. The resolution will benefit from short positron range caused by magnetic field and smaller ring diameter will also reduce the effect of non-collinearity. Thirdly, as the PET ring is mounted on head, impact of patient motion will be reduced.

Dedicated brain PET system of PET/MR for brain research

Energy Technology Data Exchange (ETDEWEB)

Cheng, Li; Liu, Yaqiang; Ma, Tianyu; Wang, Shi; Wei, Qingyang; Xu, Tianpeng [Institute of Medical Physics, Department of Engineering Physics, Tsinghua University, Beijing (China)

2015-05-18

This work is to replace PET ring in human brain PET/MR system with a dedicated wearable PET insert, aimed at improving both patient feasibility and system performance for brain imaging. The designed PET/MR system includes two parts: the inside parts, including a radio frequency (RF) coil and PET ring, are mounted on patient’s head, and the outside part, a MR imager, is dependent of patient. The RF coil is the innermost layer, surrounded by an outer PET-ring layer. They are supported by a MRcompatible structure. And both RF coil and PET detectors are placed inside a standard clinical 3-T MR imager. From the design of the system we can infer that some advantages can be achieved. First, high sensitivity will be achieved with the same amount crystals as the PET ring is more close to region-of-interest area, at a reduced cost. Second, by using a 2-layer depth of interaction (DOI) detector, the parallax effect can be minimized. The resolution will benefit from short positron range caused by magnetic field and smaller ring diameter will also reduce the effect of non-collinearity. Thirdly, as the PET ring is mounted on head, impact of patient motion will be reduced.

The drive beam pulse compression system for the CLIC RF power source

CERN Document Server

Corsini, R

1999-01-01

The Compact LInear Collider (CLIC) is a high energy (0.5 to 5 TeV) e ± linear collider that uses a high- current electron beam (the drive beam) for 30 GHz RF power production by the Two-Beam Acceleration (TBA) method. Recently, a new cost­effective and efficient generation scheme for the drive beam has been developed. A fully­loaded normal­conducting linac operating at lower frequency (937 MHz) generates and accelerates the drive beam bunches, and a compression system composed of a delay­line and two combiner rings produces the proper drive beam time structure for RF power generation in the drive beam decelerator. In this paper, a preliminary design of the whole compression system is presented. In particular, the fundamental issue of preserving the bunch quality along the complex is studied and its impact on the beam parameters and on the various system components is assessed. A first design of the rings and delay­line lattice, including path length tuning chicanes, injection and extraction regions is a...

Parameter scan for the CLIC Damping rings under the infleunce of intrabeam scattering

OpenAIRE

Antoniou, F; Martini, M; Papaphilippou, Y; Vivoli, A

2010-01-01

Due to the high bunch density, the output emittances of the CLIC Damping Rings (DR) are strongly dominated by the effect of Intrabeam Scattering (IBS). In an attempt to optimize the ring design, the bench-marking of the multiparticle tracking code SIRE with the classical IBS formalisms and approximations is first considered. The scaling of the steady state emittances and IBS growth rates is also studied, with respect to several ring parameters including energy, bunch charge and wiggler charac...

Parameter scan for the CLIC Damping rings under the infleunce of intrabeam scattering

CERN Document Server

Antoniou, F; Papaphilippou, Y; Vivoli, A

2010-01-01

Due to the high bunch density, the output emittances of the CLIC Damping Rings (DR) are strongly dominated by the effect of Intrabeam Scattering (IBS). In an attempt to optimize the ring design, the bench-marking of the multiparticle tracking code SIRE with the classical IBS formalisms and approximations is first considered. The scaling of the steady state emittances and IBS growth rates is also studied, with respect to several ring parameters including energy, bunch charge and wiggler characteristics.

18F-fluorodeoxyglucose PET and PET-CT in early detection of cancer recurrent

International Nuclear Information System (INIS)

Xing Yan; Zhao Jinhua

2007-01-01

Early detection of recurrent can improve prognosis and survival of patients with cancer. 18 F- fluorodeoxyglucose( 18 F-FDG) PET can detect metabolic changes before structural changes. The fused imaging provided by PET-CT can precisely localize the foci and demonstrate the complementary roles of functional and anatomic assessments in the diagnosis of cancer recurrence. In addition to the accurate diagnosis and definition of the whole extent of recurrent cancer, 18 F-FDG PET and PET-CT can impact patients management. (authors)

Analysis of test-beam data with hybrid pixel detector prototypes for the Compact LInear Collider (CLIC) vertex detectors

CERN Document Server

Pequegnot, Anne-Laure

2013-01-01

The LHC is currently the most powerful accelerator in the world. This proton-proton collider is now stoppped to increase significantly its luminosity and energy, which would provide a larger discovery potential in 2014 and beyond. A high-energy $e^{+}e^{-}$ collider, such as CLIC, is an option to complement and to extend the LHC physics programme. Indeed, a lepton collider gives access to additional physics processes, beyond those observable at the LHC, and therefore provides new discovery potential. It can also provide complementary and/or more precise information about new physics uncovered at the LHC. Many essential features of a detector are required to deliver the full physics potential of this CLIC machine. In this present report, I present my work on the vertex detector R\\&D for this future linear collider, which aims at developping highly granular and ultra-thin position sensitive detection devices with very low power consumption and fast time-stamping capability. We tested here thin silicon pixel...

Investigation of Hadronic Higgs Decays at CLIC at 350 GeV & Scintillator Studies for a Highly Granular Calorimeter

CERN Document Server

AUTHOR|(CDS)2081006; Simon, Frank

The energy frontier of accelerator-based physics has been dominated, for the best part of the last ten years, by the Large Hadron Collider (LHC). This remarkable accelerator has provided scientists with proton-proton collisions up to 13 TeV in energy, that led to exciting progress in the understanding of particle physics, culminating in the discovery of the Higgs boson in 2012. Despite its successes, the LHC carries an intrinsic limitation: since it collides composite particles, the initial conditions of each interaction cannot be completely determined. This limits the precision with which some observables can be measured. A new generation of colliders, designed for the acceleration of elementary electrons and positrons, is being developed to reach higher precision and to provide complementary discovery potential for new phenomena. The two most mature projects in this category are the Compact LInear Collider (CLIC) and the International Linear Collider (ILC). One key component of the physics program at CLIC i...

PACMAN – an Innovative Doctoral Programme for CLIC

CERN Multimedia

CERN Bulletin

2013-01-01

The final network project funded under the European Commission’s Seventh Framework Programme (FP7), Marie Curie Actions, held its kick-off meeting at CERN on 20 November 2013.   PACMAN – a study on Particle Accelerator Components Metrology and Alignment to the Nanometre scale – is in the final stage of recruiting 10 PhD students to do research on beam instrumentation, metrology, micrometric alignment, magnetic measurements, nano-positioning and high-precision engineering. The students will acquire multi-disciplinary expertise in advanced engineering combined with a broad span of transferable skills. “PACMAN gives us the opportunity to attract students to CERN at a key moment in the CLIC study,” said Frédérick Bordry, Head of CERN’s Technology Department. “This is also an ideal opportunity to further develop CERN’s networks with industry and universities.” “The project is...

Choke-mode damped structure design for the Compact Linear Collider main linac

CERN Document Server

Zha, Hao; Grudiev, Alexej; Huang, Wenhui; Shi, Jiaru; Tang, Chuanxiang; Wuensch, Walter

2012-01-01

Choke-mode damped structures are being studied as an alternative design to waveguide damped structures for the main linac of the Compact Linear Collider (CLIC). Choke-mode structures have the potential for lower pulsed temperature rise and simpler and less expensive fabrication. An equivalent circuit model based on transmission line theory for higher-order-mode damping is presented. Using this model, a new choke geometry is proposed and the wakefield performance is verified using GDFIDL. This structure has a comparable wakefield damping effect to the baseline design which uses waveguide damping. A prototype structure with the same iris dimensions and accelerating gradient as the nominal CLIC design, but with the new choke geometry, has been designed for high-power tests. DOI: 10.1103/PhysRevSTAB.15.122003

CLIC, a 0.5 to 5 TeV e$^{\\pm}$ Compact Linear Collider

CERN Document Server

Delahaye, J P; Braun, Hans Heinrich; Carron, G; Chautard, F; Coosemans, Williame; Corsini, R; D'Amico, T E; Dehler, M; Godot, J C; Guignard, Gilbert; Hagel, J; Hutchins, S; Johnson, C D; Jensen, E; Kamber, I; Millich, Antonio; Pearce, P; Potier, J P; Riche, A J; Rinolfi, Louis; Schulte, Daniel; Suberlucq, Guy; Thorndahl, L; Valentini, M; Warner, D J; Wilson, Ian H; Wuensch, Walter; Napoly, O; Raubenheimer, T O; Ruth, Ronald D

1998-01-01

The CLIC study of a high energy (0.5 - 5 TeV), high luminosity (10^34 - 10^35 cm^-2 sec^-1) e± linear collider is presented. Beam acceleration using high frequency (30 GHz) normal-conducting structure s operating at high accelerating fields (100 to 200 MV/m) significantly reduces the length and, in consequence the cost of the linac. Based on new beam and linac parameters derived from a recently dev eloped set of general scaling laws for linear colliders, the beam stability is shown to be similar to lower frequency designs in spite of the strong wake-field dependency on frequency. A new cost effe ctive and very efficient drive beam generation scheme for RF power production by the so-called "Two Beam Acceleration (TBA)" method is described. It uses a conventional thermionic gun and a fully-load ed normal-conducting linac operating at low frequency (937 MHz) to generate and accelerate the drive beam bunches and RF multiplication by funneling in compressor rings to produce the desired bunch st ructure. Recent 30...

Phase and amplitude stability of a pulsed RF system on the example of the CLIC drive beam LINAC

CERN Document Server

AUTHOR|(CDS)2132320; Prof. BANTEL, Michael

The CLIC drive beam accelerator consists of the Drive Beam Injector (DBI) and two Drive Beam Linacs (DBLs). The drive beam injector is composed of a thermionic electron source, 3 Sub Harmonic Bunchers (SHBs), a pre-buncher, and several acceleration structures. In the electron source the DC electron beam is produced from a thermionic cathode. The following buncher cavities group ("bunch") the electrons to be accelerated by RF later on. Each electron bunch has an energy of 140 keV, a length of 3 mm, and a charge qb = 8.4 nC. Afterwards the electrons are accelerated in the 1 GHz accelerating structures up to 50MeV. The pulsed Radio Frequency (RF) power for this acceleration is provided by 1 GHz, 20MW modulator-klystron units, one per acceleration structure. A klystron is an RF amplifier based on a linear-beam vacuum tube. The high voltage modulator supplies the acceleration voltage to this tube. A DC electron beam gets modulated with an input signal, the modulation enhances in a drift space, and finally the powe...

Mechanical design of a pre-isolator for the CLIC final focusing magnets

CERN Document Server

Gaddi, A; Ramos, F; Siegrist, N

2012-01-01

Due to the very small vertical beam sizes, the final focusing elements at the future CLIC linear collider need to be stable against vibrations to below 0.15 nanometres at frequencies above about 4 Hz. One of the key elements in the strategy to achieve such a stable environment is a passive, heavy pre-isolator. In this report, the results from the dynamic finite element analyses of the proposed design for such a passive preisolator are summarized. Furthermore, the results from a low frequency, heavy mass passive vibration isolation test set-up used to validate the calculations are shown.

The CLIC stability study on the feasibility of colliding high energy nanobeams

CERN Document Server

Assmann, R W; Guignard, Gilbert; Leros, Nicolas; Redaelli, S; Schulte, Daniel; Wilson, Ian H; Zimmermann, Frank

2002-01-01

The Compact Linear Collider (CLIC) study at CERN proposes a linear collider with nanometer-size colliding beams at an energy of 3 TeV c.m. ("colliding high energy nanobeams"). The transport, demagnification and collision of these nanobeams imposes magnet vibration tolerances that range from 0.2 nm to a few nanometers. This is well below the floor vibration usually observed. A test stand for magnet stability was set-up at CERN in the immediate neighborhood of roads, operating accelerators, workshops, and regular office space. It was equipped with modern stabilization equipment. The experimental setup and first preliminary results are presented. (10 refs).

Geometric calibration between PET scanner and structured light scanner

DEFF Research Database (Denmark)

Kjer, Hans Martin; Olesen, Oline Vinter; Paulsen, Rasmus Reinhold

2011-01-01

Head movements degrade the image quality of high resolution Positron Emission Tomography (PET) brain studies through blurring and artifacts. Manny image reconstruction methods allows for motion correction if the head position is tracked continuously during the study. Our method for motion tracking...... is a structured light scanner placed just above the patient tunnel on the High Resolution Research Tomograph (HRRT, Siemens). It continuously registers point clouds of a part of the patient's face. The relative motion is estimated as the rigid transformation between frames. A geometric calibration between...

Pets, Purity and Pollution: Why Conventional Models of Disease Transmission Do Not Work for Pet Rat Owners.

Science.gov (United States)

Robin, Charlotte; Perkins, Elizabeth; Watkins, Francine; Christley, Robert

2017-12-07

In the United Kingdom, following the emergence of Seoul hantavirus in pet rat owners in 2012, public health authorities tried to communicate the risk of this zoonotic disease, but had limited success. To explore this lack of engagement with health advice, we conducted in-depth, semi-structured interviews with pet rat owners and analysed them using a grounded theory approach. The findings from these interviews suggest that rat owners construct their pets as different from wild rats, and by elevating the rat to the status of a pet, the powerful associations that rats have with dirt and disease are removed. Removing the rat from the contaminated outside world moves their pet rat from being 'out of place' to 'in place'. A concept of 'bounded purity' keeps the rat protected within the home, allowing owners to interact with their pet, safe in the knowledge that it is clean and disease-free. Additionally, owners constructed a 'hierarchy of purity' for their pets, and it is on this structure of disease and risk that owners base their behaviour, not conventional biomedical models of disease.

Development of Stripline Kickers for Low Emittance Rings: Application to the Beam Extraction Kicker for CLIC Damping Rings

CERN Document Server

AUTHOR|(SzGeCERN)728476; Toral Fernandez, Fernando

In the framework of the design study of Future Linear Colliders, the Compact Linear Collider (CLIC) aims for electron-positron collisions with high luminosity at a nominal centre-of-mass energy of 3 TeV. To achieve the luminosity requirements, Pre-Damping Rings (PDRs) and Damping Rings (DRs) are required: they reduce the beam emittance before the beam is accelerated in the main linac. Several injection and extraction systems are needed to inject and extract the beam from the PDRs and DRs. The work of this Thesis consists of the design, fabrication and laboratory tests of the first stripline kicker prototype for beam extraction from the CLIC DRs, although the methodology proposed can be extended to stripline kickers for any low emittance ring. The excellent field homogeneity required, as well as a good transmission of the high voltage pulse through the electrodes, has been achieved by choosing a novel electrode shape. With this new geometry, it has been possible to benefit from all the advantages that the most...

submitter Measurements on a 20-layer 12.5 kV prototype inductive adder for the CLIC DR kickers

CERN Document Server

Holma, J

2018-01-01

The CLIC study is investigating the technical feasibility of an electron-positron collider with high luminosity and a nominal centre-of-mass energy of 3 TeV. The predamping rings and damping rings (DRs) will produce ultra-low emittance beam with high bunch charge. To avoid beam emittance increase, the DR kicker systems must provide extremely stable field pulses during injection and extraction of bunches. The DR extraction kicker system consists of a stripline kicker and two pulse modulators. The present specification for the modulators calls for pulses with 160 ns or 900 ns flat-top duration of nominally ±12.5 kV and 305 A, with ripple of not more than ±0.02% (±2.5 V). In addition, there is a proposal to use the same modulators and striplines for dumping the beam, with ±17.5 kV stripline pulse voltage. An inductive adder is a very promising approach to meeting the CLIC DR extraction kicker specifications because analogue modulation methods can be applied to adjust the shape of the flat-top of the output w...

Analyzing the Anomalous Dipole Moment Type Couplings of Heavy Quarks with FCNC Interactions at the CLIC

International Nuclear Information System (INIS)

Senol, A.; Tasci, A. T.; Verep, C.

2014-01-01

We examine both anomalous magnetic and dipole moment type couplings of a heavy quark via its single production with subsequent dominant standard model decay modes at the compact linear collider (CLIC). The signal and background cross sections are analyzed for heavy quark masses 600 and 700 GeV. We make the analysis to delimitate these couplings as well as to find the attainable integrated luminosities for 3σ observation limit

Processing of three-dimensional structures of Nuclear Medicine in PET modality

International Nuclear Information System (INIS)

Pacheco, Edward Florez; Furuie, Sergio Shiguemi

2013-01-01

The nuclear medicine, as a specialty to obtain medical images is very important, and it has became one of the main procedures utilized in health care centers to analyze the metabolic behavior of the patient. This project was based on medical images obtained by the PET modality (Positron Emission Tomography). Thus, we developed a framework for processing Nuclear Medicine three-dimensional images of the PET modality, which is composed of consecutive steps that start with the generation of standard images (gold standard) by using simulated images of the Left Ventricular Heart, such as phantoms obtained from the NCAT-4D software. Then, Poisson quantum noise was introduced into the whole volume to simulate the characteristic noises in PET images. Subsequently, the pre-processing step was executed by using specific 3D filters, such as the median filter, the weighted Gaussian filter, and the Anscombe/Wiener filter. Then the segmentation process, which is based on the fuzzy connectedness theory, was implemented. For that purpose four different 3D approaches were implemented: Generic, LIFO, kTetaFOEMS, and dynamic weight algorithm. Finally, an assessment procedure was used as a measurement tool to quantify three parameters (true positive, false positive and maximum distance) that determined the level of efficiency and precision of our process. It was found that the pair filter - segmenter formed by the Anscombe/Wiener filter together with the Fuzzy segmenter based on dynamic weights provided the best results, with VP and FP rates of 98.49 ±0.27% and 2.19 ±0.19%, respectively, for the simulation of the left ventricular volume. Along with the set of choices made during the processing structure, the project was finished with the analysis of a small number of volumes that belonged to a real PET test, thus the quantification of the volumes was obtained. (author)

Alignement général du CLIC: stratégie et progrès

CERN Document Server

Mainaud-Durand, H

2008-01-01

La faisabilité concernant le pré-alignement actif du CLIC sera démontrée si l?on peut prouver qu?il existe une référence et ses capteurs associés permettant l?alignement des composants à mieux que 3 microns (1?). Pour répondre à ce challenge, une méthode de mesure d?écarts à un fil tendu est proposée, basée sur 40 ans de pratique de cette technique au CERN. Quelques problèmes demeurent concernant cette méthode : la connaissance de la forme du fil tendu utilisé comme référence droite, la détermination du géoïde à la précision souhaitée et le développement de capteurs bas coût permettant des mesures sub-micrométriques. Des études ont été entreprises afin de lever les derniers points en suspens, pendant que cette solution est intégrée dans une proposition concernant l?alignement général du CLIC. Cela implique un grand nombre d?interactions au niveau du projet, dans des domaines aussi différents que le génie civil, l?intégration, la physique du faisceau, la métrologie des �...

Effects of rf breakdown on the beam in the Compact Linear Collider prototype accelerator structure

Directory of Open Access Journals (Sweden)

A. Palaia

2013-08-01

Full Text Available Understanding the effects of rf breakdown in high-gradient accelerator structures on the accelerated beam is an extremely relevant aspect in the development of the Compact Linear Collider (CLIC and is one of the main issues addressed at the Two-beam Test Stand at the CLIC Test Facility 3 at CERN. During a rf breakdown high currents are generated causing parasitic magnetic fields that interact with the accelerated beam affecting its orbit. The beam energy is also affected because the power is partly reflected and partly absorbed thus reducing the available energy to accelerate the beam. We discuss here measurements of such effects observed on an electron beam accelerated in a CLIC prototype structure. Measurements of the trajectory of bunch trains on a nanosecond time scale showed fast changes in correspondence of breakdown that we compare with measurements of the relative beam spots on a scintillating screen. We identify different breakdown scenarios for which we offer an explanation based also on measurements of the power at the input and output ports of the accelerator structure. Finally we present the distribution of the magnitude of the observed changes in the beam position and we discuss its correlation with rf power and breakdown location in the accelerator structure.

Function–structure connectivity in patients with severe brain injury as measured by MRI-DWI and FDG-PET

DEFF Research Database (Denmark)

Annen, J.; Heine, Lizette; Ziegler, E.

2016-01-01

A vast body of literature exists showing functional and structural dysfunction within the brains of patients with disorders of consciousness. However, the function (fluorodeoxyglucose FDG-PET metabolism)–structure (MRI-diffusion-weighted images; DWI) relationship and how it is affected in severel...

The CLIC Positron Capture and Acceleration in the Injector Linac.

CERN Document Server

Vivoli, Alessandro; Chehab, Robert; Dadoun, Olivier; Lepercq, Pierre; Poirier, Freddy; Rinolfi, Louis; Strakhovenko, Vladimir; Variola, Alessandro

2010-01-01

The baseline of the CLIC study considers non-polarized e+ for the 3 TeV centre of mass energy. The e+ source is based on the hybrid targets scheme, where a crystal-radiator target is followed by an amorphous-converter target. Simulations have been performed from the exit of the amorphous target up to the entrance of the Pre-Damping Ring. Downstream the amorphous target, there is an Adiabatic Matching Device (AMD) followed by a Pre-Injector Linac accelerating the e+ beam up to around 200 MeV. Then a common Injector Linac (for both e+ and e-) accelerates the beams up to 2.86 GeV before being injected into the Pre-Damping Ring. In this note, the characteristics of the AMD and the other sections are described and the beam parameters at the entrance of the Pre-Damping Ring are given.

Alignment Methods Developed for the Validation of the Thermal and Mechanical Behaviour of the Two Beam Test Modules for the CLIC Project

CERN Document Server

Mainaud Durand, Helene; Sosin, Mateusz; Rude, Vivien

2014-01-01

CLIC project will consist of more than 20 000 two meters long modules. A test setup made of three modules is being built at CERN to validate the assembly and integration of all components and technical systems and to validate the short range strategy of pre-alignment. The test setup has been installed in a room equipped with a sophisticated system of ventilation able to reproduce the environmental conditions of the CLIC tunnel. Some of the components have been equipped with electrical heaters to simulate the power dissipation, combined with a water cooling system integrated in the RF components. Using these installations, to have a better understanding of the thermal and mechanical behaviour of a module under different operation modes, machine cycles have been simulated; the misalignment of the components and their supports has been observed. This paper describes the measurements methods developed for such a project and the results obtained.

Multi-step lining-up correction of the CLIC trajectory

CERN Document Server

D'Amico, T E

1999-01-01

In the CLIC main linac it is very important to minimise the trajectory excursion and consequently the emittance dilution in order to obtain the required luminosity. Several algorithms have been proposed and lately the ballistic method has proved to be very effective. The trajectory correction method described hereafter retains the main advantages of the latter while adding some interesting features. It is based on the separation of the unknown variables like the quadrupole misalignments, the offset and slope of the injection straight line and the misalignments of the beam position monitors (BPM). This is achieved by referring the trajectory relatively to the injection line and not to the average pre-alignment line and by using two trajectories each corresponding to slightly different quadrupole strengths. A reference straight line is then derived onto which the beam is bent by a kick obtained by moving the first quadrupole. The other quadrupoles are then aligned on that line. The quality of the correction dep...

Technologies for Future Vertex and Tracking Detectors at CLIC

CERN Document Server

Spannagel, Simon

2018-01-01

CLIC is a proposed linear e$^{+}$e$^{-}$ collider with center-of-mass energies of up to 3 TeV. Its main objectives are precise top quark and Higgs boson measurements, as well as searches for Beyond Standard Model physics. To meet the physics goals, the vertex and tracking detectors require not only a spatial resolution of a few micrometers and a very low material budget, but also timing capabilities with a precision of a few nanoseconds to allow suppression of beam-induced backgrounds. Different technologies using hybrid silicon detectors are explored for the vertex detectors, such as dedicated readout ASICs, small-pitch active edge sensors as well as capacitively coupled High-Voltage CMOS sensors. Monolithic sensors are considered as an option for the tracking detector, and a prototype using a CMOS process with a high-resistivity epitaxial layer is being designed. Different designs using a silicon-on-insulator process are under investigation for both vertex and tracking detector. All prototypes are evaluate...

Estrutura da cadeia reversa: "caminhos" e "descaminhos" da embalagem PET Structure of the reverse chain: "ways" of PET packing

Directory of Open Access Journals (Sweden)

Sylmara Lopes Francelino Gonçalves-Dias

2006-12-01

Full Text Available O trabalho propõe-se a discutir as possibilidades, limites e desafios da reciclagem de PET - Politereftalato de Etileno. Como fundamentação teórico-conceitual, recorre à discussão sobre a natureza e o alcance da logística reversa, analisando as estratégias para estruturação da cadeia de reciclagem. A pesquisa é de caráter exploratório, com adoção de diferentes estratégias para a coleta de dados, envolvendo fontes secundárias produzidas por órgãos públicos, instituições especializadas e mídia, e ainda entrevistas semi-estruturadas com especialistas na área. Os resultados apontam que múltiplos atores estão envolvidos na estrutura da cadeia reversa do PET e que, apesar do avanço no volume de reciclagem, nenhum dos setores, seja público ou privado, consegue individualmente organizar-se para o alcance da efetividade operacional e ambiental desejável no cenário brasileiro. O alcance de bons resultados depende, sobretudo, do investimento nos dois extremos da cadeia reversa: na coleta seletiva e no mercado para o produto reciclado.The work discuss the possibilities, limits and challenges of the recycling of PET packing in the Brazilian case. The authors analyze the nature and the function of the reverse logistics and its strategies for articulation of the recycling chain. The research is based in the exploratory methodological approach, with adoption of different strategies for the collection of data, involving secondary sources produced by public institutions, specialized organizations and media, and still, interviews semi-structured with specialists in the area. The results point that the Brazilian public and private sectors doesn’t get to organize this activity in the desirable environmental scale. Good performances in the PET packing reverse chain depends on investing in the selective collection and in the market for the recycled products.

Correction of vertical dispersion and betatron coupling for the CLIC damping ring

CERN Document Server

Korostelev, M S

2006-01-01

The sensitivity of the CLIC damping ring to various kinds of alignment errors has been studied. Without any correction, fairly small vertical misalignments of the quadrupoles and, in particular, the sextupoles, introduce unacceptable distortions of the closed orbit as well as intolerable spurious vertical dispersion and coupling due to the strong focusing optics of the damping ring. A sophisticated beam-based correction scheme has been developed to bring the design target emittances and the dynamic aperture back to the ideal value. The correction using dipolar correctors and several skew quadrupole correctors allows a minimization of the closed-orbit distortion, the cross-talk between vertical and horizontal closed orbits, the residual vertical dispersion and the betatron coupling.

Imaging and PET - PET/CT imaging

International Nuclear Information System (INIS)

Von Schulthess, G.K.; Hany, Th.F.

2008-01-01

PET/CT has grown because the lack of anatomic landmarks in PET makes 'hardware-fusion' to anatomic cross-sectional data extremely useful. Addition of CT to PET improves specificity, but also sensitivity, and adding PET to CT adds sensitivity and specificity in tumor imaging. The synergistic advantage of adding CT is that the attenuation correction needed for PET data can also be derived from the CT data. This makes PET-CT 25-30% faster than PET alone, leading to higher patient throughput and a more comfortable examination for patients typically lasting 20 minutes or less. FDG-PET-CT appears to provide relevant information in the staging and therapy monitoring of many tumors, such as lung carcinoma, colorectal cancer, lymphoma, gynaecological cancers, melanoma and many others, with the notable exception of prostatic cancer. for this cancer, choline derivatives may possibly become useful radiopharmaceuticals. The published literature on the applications of FDG-PET-CT in oncology is still limited but several designed studies have demonstrated the benefits of PET-CT. (authors)

Evaluation of PET Scanner Performance in PET/MR and PET/CT Systems: NEMA Tests.

Science.gov (United States)

Demir, Mustafa; Toklu, Türkay; Abuqbeitah, Mohammad; Çetin, Hüseyin; Sezgin, H Sezer; Yeyin, Nami; Sönmezoğlu, Kerim

2018-02-01

The aim of the present study was to compare the performance of positron emission tomography (PET) component of PET/computed tomography (CT) with new emerging PET/magnetic resonance (MR) of the same vendor. According to National Electrical Manufacturers Association NU2-07, five separate experimental tests were performed to evaluate the performance of PET scanner of General Electric GE company; SIGNATM model PET/MR and GE Discovery 710 model PET/CT. The main investigated aspects were spatial resolution, sensitivity, scatter fraction, count rate performance, image quality, count loss and random events correction accuracy. The findings of this study demonstrated superior sensitivity (~ 4 folds) of PET scanner in PET/MR compared to PET/CT system. Image quality test exhibited higher contrast in PET/MR (~ 9%) compared with PET/CT. The scatter fraction of PET/MR was 43.4% at noise equivalent count rate (NECR) peak of 218 kcps and the corresponding activity concentration was 17.7 kBq/cc. Whereas the scatter fraction of PET/CT was found as 39.2% at NECR peak of 72 kcps and activity concentration of 24.3 kBq/cc. The percentage error of the random event correction accuracy was 3.4% and 3.1% in PET/MR and PET/CT, respectively. It was concluded that PET/MR system is about 4 times more sensitive than PET/CT, and the contrast of hot lesions in PET/MR was ~ 9% higher than PET/CT. These outcomes also emphasize the possibility to achieve excellent clinical PET images with low administered dose and/or a short acquisition time in PET/MR.

The spatial distribution of pet dogs and pet cats on the island of Ireland

Directory of Open Access Journals (Sweden)

More Simon J

2011-06-01

Full Text Available Abstract Background There is considerable international research regarding the link between human demographics and pet ownership. In several international studies, pet ownership was associated with household demographics including: the presence of children in the household, urban/rural location, level of education and age/family structure. What is lacking across all these studies, however, is an understanding of how these pets are spatially distributed throughout the regions under study. This paper describes the spatial distribution of pet dog and pet cat owning households on the island of Ireland. Results In 2006, there were an estimated 640,620 pet dog owning households and 215,542 pet cat owning households in Ireland. These estimates are derived from logistic regression modelling, based on household composition to determine pet dog ownership and the type of house to determine pet cat ownership. Results are presented using chloropleth maps. There is a higher density of pet dog owning households in the east of Ireland and in the cities than the west of Ireland and rural areas. However, in urban districts there are a lower proportion of households owning pet dogs than in rural districts. There are more households with cats in the urban areas, but the proportion of households with cats is greater in rural areas. Conclusions The difference in spatial distribution of dog ownership is a reflection of a generally higher density of households in the east of Ireland and in major cities. The higher proportion of ownership in the west is understandable given the higher proportion of farmers and rural dwellings in this area. Spatial representation allows us to visualise the impact of human household distribution on the density of both pet dogs and pet cats on the island of Ireland. This information can be used when analysing risk of disease spread, for market research and for instigating veterinary care.

Inter-subject FDG PET Brain Networks Exhibit Multi-scale Community Structure with Different Normalization Techniques.

Science.gov (United States)

Sperry, Megan M; Kartha, Sonia; Granquist, Eric J; Winkelstein, Beth A

2018-07-01

Inter-subject networks are used to model correlations between brain regions and are particularly useful for metabolic imaging techniques, like 18F-2-deoxy-2-(18F)fluoro-D-glucose (FDG) positron emission tomography (PET). Since FDG PET typically produces a single image, correlations cannot be calculated over time. Little focus has been placed on the basic properties of inter-subject networks and if they are affected by group size and image normalization. FDG PET images were acquired from rats (n = 18), normalized by whole brain, visual cortex, or cerebellar FDG uptake, and used to construct correlation matrices. Group size effects on network stability were investigated by systematically adding rats and evaluating local network connectivity (node strength and clustering coefficient). Modularity and community structure were also evaluated in the differently normalized networks to assess meso-scale network relationships. Local network properties are stable regardless of normalization region for groups of at least 10. Whole brain-normalized networks are more modular than visual cortex- or cerebellum-normalized network (p network resolutions where modularity differs most between brain and randomized networks. Hierarchical analysis reveals consistent modules at different scales and clustering of spatially-proximate brain regions. Findings suggest inter-subject FDG PET networks are stable for reasonable group sizes and exhibit multi-scale modularity.

Processing of three-dimensional structures of Nuclear Medicine in PET modality; Processamento de estruturas tridimensionais de medicina nuclear na modalidade PET

Energy Technology Data Exchange (ETDEWEB)

Pacheco, Edward Florez; Furuie, Sergio Shiguemi, E-mail: edward.florez@usp.br [Universidade de Sao Paulo (EP/USP), SP (Brazil). Dept. de Engenharia de Telecomunicacoes e Controle. Lab. de Engenharia Biomedica

2013-03-15

The nuclear medicine, as a specialty to obtain medical images is very important, and it has became one of the main procedures utilized in health care centers to analyze the metabolic behavior of the patient. This project was based on medical images obtained by the PET modality (Positron Emission Tomography). Thus, we developed a framework for processing Nuclear Medicine three-dimensional images of the PET modality, which is composed of consecutive steps that start with the generation of standard images (gold standard) by using simulated images of the Left Ventricular Heart, such as phantoms obtained from the NCAT-4D software. Then, Poisson quantum noise was introduced into the whole volume to simulate the characteristic noises in PET images. Subsequently, the pre-processing step was executed by using specific 3D filters, such as the median filter, the weighted Gaussian filter, and the Anscombe/Wiener filter. Then the segmentation process, which is based on the fuzzy connectedness theory, was implemented. For that purpose four different 3D approaches were implemented: Generic, LIFO, kTetaFOEMS, and dynamic weight algorithm. Finally, an assessment procedure was used as a measurement tool to quantify three parameters (true positive, false positive and maximum distance) that determined the level of efficiency and precision of our process. It was found that the pair filter - segmenter formed by the Anscombe/Wiener filter together with the Fuzzy segmenter based on dynamic weights provided the best results, with VP and FP rates of 98.49 {+-}0.27% and 2.19 {+-}0.19%, respectively, for the simulation of the left ventricular volume. Along with the set of choices made during the processing structure, the project was finished with the analysis of a small number of volumes that belonged to a real PET test, thus the quantification of the volumes was obtained. (author)

Beam-based alignment of CLIC drive beam decelerator using girders movers

CERN Document Server

Sterbini, G

2011-01-01

The CLIC drive beams will provide the rf power to accelerate the colliding beams: in order to reach the design performance, an efficient transport of the drive beam has to be ensured in spite of its challenging energy spread and large current intensity. As shown in previous studies, the specifications can be met by coupling a convenient optics design with the state-of-the-art of pre-alignment and beambased alignment techniques. In this paper we consider a novel beam-based alignment scheme that does not require quadrupole movers or dipole correctors but uses the motors already foreseen for the pre-alignment system. This implies potential savings in terms of complexity and cost at the expense of the alignment flexibility: the performance, limitations and sensitivity to pre-alignment tolerances of this method are discussed.

Beam dynamics simulations in the photo-cathode RF gun for the CLIC test facility

International Nuclear Information System (INIS)

Marchand, P.; Rinolfi, L.

1992-01-01

The CERN CLIC Test Facility (CTF) uses an RF gun with a laser driven photo-cathode in order to generate electron pulses of high charge (≥10 nC) and short duration (≤20 ps). The RF gun consists of a 3 GHz 1 + 1/2 cell cavity based on the design originally proposed at BNL which minimizes the non-linearities in the transverse field. The beam dynamics in the cavity is simulated by means of the multiparticle tracking code PARMELA. The results are compared to previous simulations as well as to the first experimental data. (author). 4 refs., 4 tabs., 4 figs

A prospective multi-centre study of the value of FDG-PET as part of a structured diagnostic protocol in patients with fever of unknown origin

International Nuclear Information System (INIS)

Bleeker-Rovers, Chantal P.; Vos, Fidel J.; Meer, Jos W.M. van der; Mudde, Aart H.; Dofferhoff, Anton S.M.; Geus-Oei, Lioe-Fee de; Rijnders, Anton J.; Krabbe, Paul F.M.; Corstens, Frans H.M.; Oyen, Wim J.G.

2007-01-01

Since 18 F-fluorodeoxyglucose (FDG) accumulates in neoplastic cells and in activated inflammatory cells, positron emission tomography (PET) with FDG could be valuable in diagnosing patients with fever of unknown origin (FUO). The aim of this study was to validate the use of FDG-PET as part of a structured diagnostic protocol in the general patient population with FUO. From December 2003 to July 2005, 70 patients with FUO were recruited from one university hospital (n=38) and five community hospitals (n=32). A structured diagnostic protocol including FDG-PET was used. A dedicated, full-ring PET scanner was used for data acquisition. FDG-PET scans were interpreted by two staff members of the department of nuclear medicine without further clinical information. The final clinical diagnosis was used for comparison with the FDG-PET results. Of all scans, 33% were clinically helpful. The contribution of FDG-PET to the final diagnosis did not differ significantly between patients diagnosed in the university hospital and patients diagnosed in the community hospitals. FDG-PET contributed significantly more often to the final diagnosis in patients with continuous fever than in patients with periodic fever. FDG-PET was not helpful in any of the patients with normal erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). FDG-PET is a valuable imaging technique as part of a diagnostic protocol in the general patient population with FUO and a raised ESR or CRP. (orig.)

Issues and Feasibility Demonstration of Positioning Closed Loop Control for the CLIC Supporting System Using a Test Mock-up with Five Degrees of Freedom

CERN Document Server

Sosin, M; Chritin, N; Griffet, S; Kemppinen, J; Mainaud Durand, H; Rude, V; Sterbini, G

2012-01-01

Since several years, CERN is studying the feasibility of building a high energy e+ e- linear collider: the CLIC (Compact LInear Collider). One of the challenges of such a collider is the pre-alignment precision and accuracy requirement on the transverse positions of the linac components, which is typically 14 μm over a window of 200 m. To ensure the possibility of positioning within such tight constraints, CERN Beams Department’s Survey team has worked intensively at developing the methods and technology needed to achieve that objective. This paper describes activities which were performed on a test bench (mock-up) with five degrees of freedom (DOF) for the qualification of control algorithms for the CLIC supporting system active-pre-alignment. Present understanding, lessons learned (“know how”), issues of sensors noise and mechanical components nonlinearities are presented.

FDG-PET and FDG-PET/CT for therapy monitoring and restaging in malignant lymphoma

International Nuclear Information System (INIS)

Mottaghy, F.M.; Krause, B.J.

2003-01-01

F-18-fluorodeoxyglucose (FDG) PET allows to assess residual masses in patients with malignant lymphoma differentiating vital tumor from scar tissue. This approach is not applicable with conventional imaging methods (CDM) such as CT or MRI. On the other hand circumscribed results often cannot be definitely allocated in PET, therefore the combined morphological-biochemical approach using the now available PET/CT systems promises to be a pathbreaking technical progress. There is no doubt that stand alone PET is superior to CDM differentiating residual scar tissue from vital tumor as has been shown in 15 recently published studies. The median sensitivity for detecting active disease with FDG PET across the studies was 91%; the corresponding specificity was 89%. As a result FDG PET had a high negative predictive value of 94%. In contrast, specificity and positive predictive value (PPV) of CDM in the 9 studies were a direct comparison was available were low (31% and 46%, one study 82%). PET positive residual masses were associated with a progression-free survival of 0 - 55%. Only a few studies have included FDG-PET in therapy response monitoring studies, however also these results are promising. At the moment FDG-PET seems to be the best possibility to characterize and qualitatively visualize vitality of tumor masses and also hold promises for efficient therapy response monitoring in patients with malignant lymphoma. Therefore it should be included in standard diagnostic protocols in lymphoma patients. The combined PET/CT has to be ranked superior to conventional PET studies as in many cases the combined structural and functional imaging brings a clearer diagnostic statement. (orig.) [de

Capacitively coupled hybrid pixel assemblies for the CLIC vertex detector

CERN Document Server

AUTHOR|(SzGeCERN)734627; Benoit, Mathieu; Dannheim, Dominik; Dette, Karola; Hynds, Daniel; Kulis, Szymon; Peric, Ivan; Petric, Marko; Redford, Sophie; Sicking, Eva; Valerio, Pierpaolo

2016-01-01

The vertex detector at the proposed CLIC multi-TeV linear e+e- collider must have minimal material content and high spatial resolution, combined with accurate time-stamping to cope with the expected high rate of beam-induced backgrounds. One of the options being considered is the use of active sensors implemented in a commercial high-voltage CMOS process, capacitively coupled to hybrid pixel ASICs. A prototype of such an assembly, using two custom designed chips (CCPDv3 as active sensor glued to a CLICpix readout chip), has been characterised both in the lab and in beam tests at the CERN SPS using 120 GeV/c positively charged hadrons. Results of these characterisation studies are presented both for single and dual amplification stages in the active sensor. Pixel cross-coupling results are also presented, showing the sensitivity to placement precision and planarity of the glue layer.

Low-level feedback control for the phase regulation of CLIC Drive Beam Klystrons

CERN Document Server

AUTHOR|(SzGeCERN)752526

2015-01-01

The requirement of luminosity loss below 1% raises tight tolerances for the phase and power stability of the CLIC drive beam (DB) klystrons and consequently for the high voltage pulse ripple of the modulators. A low-level RF (LLRF) feedback system needs to be developed and combined with the modulator in order to guarantee the phase and amplitude tolerances. To this aim, three feedback control strategies were investigated, i) Proportional Integral (PI) controller, ii) Linear Quadratic Integral Regulator (LQI) and iii) Model Predictive Controller (MPC). The klystron, as well as the incident phase noise were modelled and used for the design and evaluation of the controllers. First simulation results are presented along with future steps and directions.

Thermally Induced Ultra High Cycle Fatigue of Copper Alloys of the High Gradient Accelerating Structures

CERN Document Server

Heikkinen, Samuli; Wuensch, Walter

2010-01-01

In order to keep the overall length of the compact linear collider (CLIC), currently being studied at the European Organization for Nuclear Research (CERN), within reasonable limits, i.e. less than 50 km, an accelerating gradient above 100 MV/m is required. This imposes considerable demands on the materials of the accelerating structures. The internal surfaces of these core components of a linear accelerator are exposed to pulsed radio frequency (RF) currents resulting in cyclic thermal stresses expected to cause surface damage by fatigue. The designed lifetime of CLIC is 20 years, which results in a number of thermal stress cycles of the order of 2.33•1010. Since no fatigue data existed in the literature for CLIC parameter space, a set of three complementary experiments were initiated: ultra high cycle mechanical fatigue by ultrasound, low cycle fatigue by pulsed laser irradiation and low cycle thermal fatigue by high power microwaves, each test representing a subset of the original problem. High conductiv...

Comparison of PET/CT with Sequential PET/MRI Using an MR-Compatible Mobile PET System.

Science.gov (United States)

Nakamoto, Ryusuke; Nakamoto, Yuji; Ishimori, Takayoshi; Fushimi, Yasutaka; Kido, Aki; Togashi, Kaori

2018-05-01

The current study tested a newly developed flexible PET (fxPET) scanner prototype. This fxPET system involves dual arc-shaped detectors based on silicon photomultipliers that are designed to fit existing MRI devices, allowing us to obtain fused PET and MR images by sequential PET and MR scanning. This prospective study sought to evaluate the image quality, lesion detection rate, and quantitative values of fxPET in comparison with conventional whole-body (WB) PET and to assess the accuracy of registration. Methods: Seventeen patients with suspected or known malignant tumors were analyzed. Approximately 1 h after intravenous injection of 18 F-FDG, WB PET/CT was performed, followed by fxPET and MRI. For reconstruction of fxPET images, MRI-based attenuation correction was applied. The quality of fxPET images was visually assessed, and the number of detected lesions was compared between the 2 imaging methods. SUV max and maximum average SUV within a 1 cm 3 spheric volume (SUV peak ) of lesions were also compared. In addition, the magnitude of misregistration between fxPET and MR images was evaluated. Results: The image quality of fxPET was acceptable for diagnosis of malignant tumors. There was no significant difference in detectability of malignant lesions between fxPET and WB PET ( P > 0.05). However, the fxPET system did not exhibit superior performance to the WB PET system. There were strong positive correlations between the 2 imaging modalities in SUV max (ρ = 0.88) and SUV peak (ρ = 0.81). SUV max and SUV peak measured with fxPET were approximately 1.1-fold greater than measured with WB PET. The average misregistration between fxPET and MR images was 5.5 ± 3.4 mm. Conclusion: Our preliminary data indicate that running an fxPET scanner near an existing MRI system provides visually and quantitatively acceptable fused PET/MR images for diagnosis of malignant lesions. © 2018 by the Society of Nuclear Medicine and Molecular Imaging.

Drive Beam Quadrupoles for the CLIC Project: a Novel Method of Fiducialisation and a New Micrometric Adjustment System

CERN Document Server

AUTHOR|(SzGeCERN)411678; Duquenne, Mathieu; Sandomierski, Jacek; Sosin, Mateusz; Rude, Vivien

2014-01-01

This paper presents a new method of fiducialisation applied to determine the magnetic axis of the Drive Beam quadrupole of the CLIC project with respect to external alignment fiducials, within a micrometric accuracy and precision. It introduces also a new micrometric adjustment system along 5 Degrees of Freedom, developed for the same Drive Beam quadrupole. The combination of both developments opens very interesting perspectives to get a more simple and accurate alignment of the quadrupoles.

Compensation for photon attenuation in PET

International Nuclear Information System (INIS)

Chintu Chen; Ordonez, C.E.; Xiaolin Yu.

1992-01-01

CT/MR and PET images usually are not in registration spatially because of differences in the imaging setup. CT, MR and PET imaging parameters that are used regularly for brain studies in their institution are compared, in addition, because the patient orientations in CT/MR and PET scanners are not the same, slice centers are positioned differently relative to the patients anatomy. For application of the new idea of using structural information from CT or MR images in PET image reconstruction for attenuation correction, image registration is required as a first step so that one can obtain a corresponding anatomic map for any selected PET image plane. The authors chose to use the surface-matching technique developed in their laboratories for image registration because this method is retrospective and accurate. After the PET and CT/MR scans are registered, they reslice the CT/MR images along the planes of the PET images. The differences in slice thickness and slice separation, as well as in image resolution between various image modalities are to be considered

Comparison between PET/MR and PET/CT in evaluation of oncological patients%PET/MR与PET/CT的对比研究

Institute of Scientific and Technical Information of China (English)

徐白萱; 富丽萍; 关志伟; 尹大一; 刘家金; 杨晖; 张锦明; 陈英茂; 安宁豫

2014-01-01

Objective To verify the feasibility of the integrated PET/MR for oncological applications by comparing PET/MR with PET/CT in terms of lesion detection and quantitative measurement.Methods A total of 277 patients (165 males,112 females,average age (52.9± 12.6) years) voluntarily participated in this same-day PET/CT and PET/MR comparative study.The time interval between the two studies was 15-35 min.PET/CT images were acquired and reconstructed following standard protocols.PET/MR covered the body trunk with a sequence combination of transverse T1 weighted imaging (WI) 3D-volumetric interpolated breath-hold,T2WI turbo spin echo with fat saturation,diffusion-weighted imaging,and simultaneous PET acquisition.PET images were reconstructed by vender-provided attenuation correction methods.The results of PET/CT and PET/MR were regarded as positive if any modality (CT,PET or MRI) was positive.SUVmax was obtained by the manually drawn ROI.Detection rates were compared with x2 test and SUVmax from the two modalities was analyzed with Spearman correlation analysis.Results A total of 353 lesions were detected in 220 patients.Compared to PET/CT,PET/MR revealed 30 additional true-positive lesions,while missed 6.The detection rates between PET/CT and PET/MR were significantly different (P＜0.05).The lesion-based and patient-based consistency was 89.8％ (317/353) and 85.9％ (189/220),respectively.There were significant correlations of SUVmax between PET/MR and PET/CT for lesions(rs =0.91,P＜0.01) and for normal tissues(rs =0.62-0.76,all P＜0.01).Conclusions With reference to PET/CT,integrated PET/MR may provide comparable semi-quantitative measurements of pathological lesions as well as normal tissues.Integrated PET/MR may be more effective to detect lesions in abdomen and pelvis.%目的 通过与PET/CT在病灶检测及定量分析方面的比较,论证PET/MR一体机应用于临床的可行性.方法 2012年5月至2013年2月共300例患者同天间隔15 ～ 35 min行PET/CT和PET

A New Technique For Information Processing of CLIC Technical Documentation

CERN Document Server

Tzermpinos, Konstantinos

2013-01-01

The scientific work presented in this paper could be described as a novel, systemic approach to the process of organization of CLIC documentation. The latter refers to the processing of various sets of archived data found on various CERN archiving services in a more friendly and organized way. From physics aspect, this is equal to having an initial system characterized by high entropy, which after some transformation of energy and matter will produce a final system of reduced entropy. However, this reduction in entropy can be considered valid for open systems only, which are sub-systems of grander isolated systems, to which the total entropy will always increase. Thus, using as basis elements from information theory, systems theory and thermodynamics, the unorganized form of data pending to be organized to a higher form, is modeled as an initial open sub-system with increased entropy, which, after the processing of information, will produce a final system with decreased entropy. This systemic approach to the ...

Pet Problems at Home: Pet Problems in the Community.

Science.gov (United States)

Soltow, Willow

1984-01-01

Discusses problems of pets in the community, examining the community's role related to disruptive pets and pet overpopulation. Also discusses pet problems at home, offering advice on selecting a pet, meeting a pet's needs, and disciplining pets. Includes a list of books, films/filmstrips, teaching materials, and various instructional strategies.…

A first estimate of the structure and density of the populations of pet cats and dogs across Great Britain.

Science.gov (United States)

Aegerter, James; Fouracre, David; Smith, Graham C

2017-01-01

Policy development, implementation, and effective contingency response rely on a strong evidence base to ensure success and cost-effectiveness. Where this includes preventing the establishment or spread of zoonotic or veterinary diseases infecting companion cats and dogs, descriptions of the structure and density of the populations of these pets are useful. Similarly, such descriptions may help in supporting diverse fields of study such as; evidence-based veterinary practice, veterinary epidemiology, public health and ecology. As well as maps of where pets are, estimates of how many may rarely, or never, be seen by veterinarians and might not be appropriately managed in the event of a disease outbreak are also important. Unfortunately both sources of evidence are absent from the scientific and regulatory literatures. We make this first estimate of the structure and density of pet populations by using the most recent national population estimates of cats and dogs across Great Britain and subdividing these spatially, and categorically across ownership classes. For the spatial model we used the location and size of veterinary practises across GB to predict the local density of pets, using client travel time to define catchments around practises, and combined this with residential address data to estimate the rate of ownership. For the estimates of pets which may provoke problems in managing a veterinary or zoonotic disease we reviewed the literature and defined a comprehensive suite of ownership classes for cats and dogs, collated estimates of the sub-populations for each ownership class as well as their rates of interaction and produced a coherent scaled description of the structure of the national population. The predicted density of pets varied substantially, with the lowest densities in rural areas, and the highest in the centres of large cities where each species could exceed 2500 animals.km-2. Conversely, the number of pets per household showed the opposite

Evaluation of PET Scanner Performance in PET/MR and PET/CT Systems: NEMA Tests

OpenAIRE

Mustafa Demir; Türkay Toklu; Mohammad Abuqbeitah; Hüseyin Çetin; H. Sezer Sezgin; Nami Yeyin; Kerim Sönmezoğlu

2018-01-01

Objective: The aim of the present study was to compare the performance of positron emission tomography (PET) component of PET/computed tomography (CT) with new emerging PET/magnetic resonance (MR) of the same vendor. Methods: According to National Electrical Manufacturers Association NU2-07, five separate experimental tests were performed to evaluate the performance of PET scanner of General Electric GE company; SIGNATM model PET/MR and GE Discovery 710 model PET/CT. The main investigated...

Evaluation of PET Scanner Performance in PET/MR and PET/CT Systems: NEMA Tests

OpenAIRE

Demir, Mustafa; Toklu, Türkay; Abuqbeitah, Mohammad; Çetin, Hüseyin; Sezgin, H. Sezer; Yeyin, Nami; Sönmezoğlu, Kerim

2018-01-01

Objective: The aim of the present study was to compare the performance of positron emission tomography (PET) component of PET/computed tomography (CT) with new emerging PET/magnetic resonance (MR) of the same vendor. Methods: According to National Electrical Manufacturers Association NU2-07, five separate experimental tests were performed to evaluate the performance of PET scanner of General Electric GE company; SIGNATM model PET/MR and GE Discovery 710 model PET/CT. The main investigated asp...

Material and Structural Performance Evaluations of Hwangtoh Admixtures and Recycled PET Fiber-Added Eco-Friendly Concrete for CO₂ Emission Reduction.

Science.gov (United States)

Koo, Bon-Min; Kim, Jang-Ho Jay; Kim, Sung-Bae; Mun, Sungho

2014-08-19

In order to reduce carbon dioxide (CO₂) emissions and produce an eco-friendly construction material, a type of concrete that uses a minimal amount of cement, yet still retains equivalent properties to ordinary cement concrete, has been developed and studied all over the world. Hwangtoh, a type of red clay broadly deposited around the world, has traditionally been considered an eco-friendly construction material, with bonus advantages of having health and cost benefits. Presently, Hwangtoh is not commonly used as a modern construction material due to properties such as low strength and high rates of shrinkage cracking. Recent studies, however, have shown that Hwangtoh can be used as a mineral admixture to improve the strength of concrete. In addition, polyethylene terephthalate (PET) fibers recycled from PET bottle waste can be used to control shrinkage cracks in Hwangtoh concrete. Therefore, in this study, performance verification is conducted on newly developed Hwangtoh concrete mixed with short recycled PET fibers. The results show that Hwangtoh concrete has compressive strength, elastic modulus, and pH properties that are similar to these features in ordinary cement concrete. The properties of carbonation depth and creep strain of Hwangtoh concrete, however, are larger and smaller, respectively, than in ordinary cement concrete. According to flexural tests, reinforced concrete (RC) specimens cast with Hwangtoh admixtures (with and without PET fibers) possess similar or better capacities than ordinary RC specimens. The addition of PET fibers significantly improves the structural ductility of RC specimens under normal environmental conditions. However, the implementations of the concrete in aggressive environment must be carefully considered, since a previous study result indicates degradation of its durability performance in aggressive environments, such as seawater [1]. The results of this study validate the possibility of using eco-friendly Hwangtoh concrete

New perspective in high tech radiotherapy planning using PET/CT images (Radiation oncologist's view on PET/CT usage)

International Nuclear Information System (INIS)

Hadjieva, T.; Bildirev, N.; Koleva, I.; Zahariev, Z.; Vasileva, V.; Encheva, E.; Sultanov, B.

2010-01-01

Biological images provided by 18F-FDG PET in combination with structural X ray picture currently offer the most accurate available information on tumour staging, curative antitumour effect for prognosis, impairment of organ function after treatment, as well as primary tumour detection in unknown primary metastatic disease. The authors as radiation oncologists critically have analyzed numerous clinical trials and two guidelines to prove PET/ CT benefit in radiotherapy practice. At present they found lack of scientific evidence to confirm that patient outcomes are superior as a result of the use of PET in RT planning. PET/CT offers a best image for tumour delineation only in some cases of lung cancer, mediastinal lymph nodes and malignant lymphomas. 11C methionin PET adds additional information on postoperative MRI image for brain tumours. Inflammation as postradiation phenomenon, as well as physiological organ movements leads to false-positive PET signal. High tech radiotherapy methods require delineation on precise images given after multidisciplinary team expertise - a practice that is possible only in clinical trials, These unsolved problems have raised many ethical challenges in medical, scientific and social aspect, if wide and routine use of FDG-PET u PET/CT is advocated. (authors)

Preliminary design of the pulse generator for the CLIC damping ring extraction system

CERN Document Server

Holma, Janne; Ovaska, Seppo

2011-01-01

The spent drive beam must be cleanly extracted and bent away from the decelerator axis at the end of each CLIC decelerator in order to leave space for injecting a fresh beam train in the next sector. Then the spent beam must be safely absorbed. A compact extraction system made of a single dipole is proposed. The spent beam is driven to a water dump located at 20m downstream of the extraction point and transversely 6m away of the axis of the main linac. An adequate spread of the beam impact map on the dump offers small temperature excursions in both the dump and its entrance window, allowing for reliable operation and a long lifetime of the system.

STRUCTURAL, OPTICAL AND ELECTRICAL PROPERTIES OF PET POLYMER FILMS MODIFIED BY LOW ENERGY Ar+ ION BEAMS

Science.gov (United States)

Fawzy, Y. H. A.; Abdel-Hamid, H. M.; El-Okr, M. M.; Atta, A.

Polyethylene terephthalate (PET) films with thickness 40μm are irradiated with 3keV argon ion beams with different fluence ranging from 0.5×1018ions.cm-2 to 2×1018ions.cm-2 using locally designed broad ion source. The changes in the PET structure are characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) and scanning electron microscope (SEM) techniques. The XRD patterns show that the peak intensity decreases with irradiation and the particle size decreases from 65.75 Å for the un-irradiated to 52.80 Å after irradiation. The FTIR indicates partial decrease and reduction in the intensity of the bands due to the degradation of the polymer after ion irradiation. The optical energy band gap decreases from 3.14eV to 3.05eV and the number of carbon cluster increases from 119 to 126 after ion irradiation. The results show a slight increase in the electrical conductivities and the dielectric constant (ɛ). The results indicate the effectiveness of using PET films as capacitors and resistors in industrial applications.

Towards Implementing an MR-based PET Attenuation Correction Method for Neurological Studies on the MR-PET Brain Prototype

Science.gov (United States)

Catana, Ciprian; van der Kouwe, Andre; Benner, Thomas; Michel, Christian J.; Hamm, Michael; Fenchel, Matthias; Fischl, Bruce; Rosen, Bruce; Schmand, Matthias; Sorensen, A. Gregory

2013-01-01

A number of factors have to be considered for implementing an accurate attenuation correction (AC) in a combined MR-PET scanner. In this work, some of these challenges were investigated and an AC method based entirely on the MR data obtained with a single dedicated sequence was developed and used for neurological studies performed with the MR-PET human brain scanner prototype. Methods The focus was on the bone/air segmentation problem, the bone linear attenuation coefficient selection and the RF coil positioning. The impact of these factors on the PET data quantification was studied in simulations and experimental measurements performed on the combined MR-PET scanner. A novel dual-echo ultra-short echo time (DUTE) MR sequence was proposed for head imaging. Simultaneous MR-PET data were acquired and the PET images reconstructed using the proposed MR-DUTE-based AC method were compared with the PET images reconstructed using a CT-based AC. Results Our data suggest that incorrectly accounting for the bone tissue attenuation can lead to large underestimations (>20%) of the radiotracer concentration in the cortex. Assigning a linear attenuation coefficient of 0.143 or 0.151 cm−1 to bone tissue appears to give the best trade-off between bias and variability in the resulting images. Not identifying the internal air cavities introduces large overestimations (>20%) in adjacent structures. Based on these results, the segmented CT AC method was established as the “silver standard” for the segmented MR-based AC method. Particular to an integrated MR-PET scanner, ignoring the RF coil attenuation can cause large underestimations (i.e. up to 50%) in the reconstructed images. Furthermore, the coil location in the PET field of view has to be accurately known. Good quality bone/air segmentation can be performed using the DUTE data. The PET images obtained using the MR-DUTE- and CT-based AC methods compare favorably in most of the brain structures. Conclusion An MR-DUTE-based AC

Toward implementing an MRI-based PET attenuation-correction method for neurologic studies on the MR-PET brain prototype.

Science.gov (United States)

Catana, Ciprian; van der Kouwe, Andre; Benner, Thomas; Michel, Christian J; Hamm, Michael; Fenchel, Matthias; Fischl, Bruce; Rosen, Bruce; Schmand, Matthias; Sorensen, A Gregory

2010-09-01

Several factors have to be considered for implementing an accurate attenuation-correction (AC) method in a combined MR-PET scanner. In this work, some of these challenges were investigated, and an AC method based entirely on the MRI data obtained with a single dedicated sequence was developed and used for neurologic studies performed with the MR-PET human brain scanner prototype. The focus was on the problem of bone-air segmentation, selection of the linear attenuation coefficient for bone, and positioning of the radiofrequency coil. The impact of these factors on PET data quantification was studied in simulations and experimental measurements performed on the combined MR-PET scanner. A novel dual-echo ultrashort echo time (DUTE) MRI sequence was proposed for head imaging. Simultaneous MR-PET data were acquired, and the PET images reconstructed using the proposed DUTE MRI-based AC method were compared with the PET images that had been reconstructed using a CT-based AC method. Our data suggest that incorrectly accounting for the bone tissue attenuation can lead to large underestimations (>20%) of the radiotracer concentration in the cortex. Assigning a linear attenuation coefficient of 0.143 or 0.151 cm(-1) to bone tissue appears to give the best trade-off between bias and variability in the resulting images. Not identifying the internal air cavities introduces large overestimations (>20%) in adjacent structures. On the basis of these results, the segmented CT AC method was established as the silver standard for the segmented MRI-based AC method. For an integrated MR-PET scanner, in particular, ignoring the radiofrequency coil attenuation can cause large underestimations (i.e., PET field of view has to be accurately known. High-quality bone-air segmentation can be performed using the DUTE data. The PET images obtained using the DUTE MRI- and CT-based AC methods compare favorably in most of

Effect of PET functionalization in composites of

Directory of Open Access Journals (Sweden)

Cristina Cazan

2017-03-01

Full Text Available The functionalization of polyethylene terephthalate (PET from tire rubber–PET–high density polyethylene (HDPE composites represents a key strategy for improving the composite properties. This is a practical and effective method to improve the interface between matrix (waste tire rubber and fillers (waste PET and HDPE. By PET functionalization, adherence and surface properties of composite materials can be controlled. PET functionalization was performed with polyethylene glycol (PEG 400, 1% and sodium dodecyl sulphate (SDS 1%. The characterization of the components and composite are discussed in terms of surface energy values (evaluated from water contact angle measurements and surface morphology by using scanning electron microscopy (SEM. The structural and conformational changes were investigated by Fourier Transform Infrared (FTIR Spectroscopy while the crystalline structure was studied by X-ray diffraction (XRD. The improved interfacial adhesion, thermal stability and mechanical properties (stress–strain, compression and impact resistance of the composites are correlated with the PET functionalization, with non-ionic (PEG and an anionic surfactant (SDS. The results proved that the interface properties are improved by functionalization of PET. The best mechanical properties were recorded at 30 min moulding. The samples with 45% PET–SDS showed the best combination of mechanical properties: tensile strength (1.56 N/mm2, impact strength (43.72 kJ/m2 and compression (158.78 N/mm2.

Study of the hybrid controller electronics for the nano-stabilization of mechanical vibrations of CLIC quadrupoles

International Nuclear Information System (INIS)

Carmona, P Fernandez; Artoos, K; Esposito, M; Guinchard, M; Janssens, S; Kuzmin, A; Ballester, R Moron; Collette, C

2011-01-01

In order to achieve the required levels of luminosity in the CLIC linear collider, mechanical stabilization of quadrupoles to the nanometre level is required. The paper describes a design of hybrid electronics combining an analogue controller and digital communication with the main machine controller. The choice of local analogue control ensures the required low latency while still keeping sufficiently low noise level. Furthermore, it reduces the power consumption, rack space and cost. Sensitivity to radiation single events upsets is reduced compared to a digital controller. The digital part is required for fine tuning and real time monitoring via digitization of critical parameters.

Measurement of Higgs decay to WW$^{*}$ in Higgsstrahlung at $\\sqrt{s}=500$ GeV ILC and in WW-fusion at $\\sqrt{s}=3$ TeV CLIC

CERN Document Server

AUTHOR|(SzGeCERN)718111

2017-01-01

This talk presents results of the two independent analyses evaluating the measurement accuracy of the branching ratio for the Standard model Higgs boson decay to a W-pair, at the Compact Linear Collider (CLIC) and at the International Linear Collider (ILC). The considered Higgs production channels are the WW-fusion for the highest energy stage of CLIC, $\\sqrt{s}=3$ TeV, and the Higgsstrahlung process for the nominal ILC energy, $\\sqrt{s}=500$ GeV. Both studies are performed using the full simulation of the detector. The realistic experimental conditions have been simulated including beam energy spectrum, initial state radiation and the background from $\\gamma \\gamma \\rightarrow hadrons$ processes, which are overlaid on simulated events. The multivariate analysis technique is used for the final event selection and the expected relative statistical uncertainty, $\\Delta ( \\sigma \\cdot BR)/(\\sigma \\cdot BR)$, of the measured Higgs production cross sections is estimated.

Comparison of lesion detection and quantitation of tracer uptake between PET from a simultaneously acquiring whole-body PET/MR hybrid scanner and PET from PET/CT

International Nuclear Information System (INIS)

Wiesmueller, Marco; Schmidt, Daniela; Beck, Michael; Kuwert, Torsten; Gall, Carl C. von; Quick, Harald H.; Navalpakkam, Bharath; Lell, Michael M.; Uder, Michael; Ritt, Philipp

2013-01-01

PET/MR hybrid scanners have recently been introduced, but not yet validated. The aim of this study was to compare the PET components of a PET/CT hybrid system and of a simultaneous whole-body PET/MR hybrid system with regard to reproducibility of lesion detection and quantitation of tracer uptake. A total of 46 patients underwent a whole-body PET/CT scan 1 h after injection and an average of 88 min later a second scan using a hybrid PET/MR system. The radioactive tracers used were 18 F-deoxyglucose (FDG), 18 F-ethylcholine (FEC) and 68 Ga-DOTATATE (Ga-DOTATATE). The PET images from PET/CT (PET CT ) and from PET/MR (PET MR ) were analysed for tracer-positive lesions. Regional tracer uptake in these foci was quantified using volumes of interest, and maximal and average standardized uptake values (SUV max and SUV avg , respectively) were calculated. Of the 46 patients, 43 were eligible for comparison and statistical analysis. All lesions except one identified by PET CT were identified by PET MR (99.2 %). In 38 patients (88.4 %), the same number of foci were identified by PET CT and by PET MR . In four patients, more lesions were identified by PET MR than by PET CT , in one patient PET CT revealed an additional focus compared to PET MR . The mean SUV max and SUV avg of all lesions determined by PET MR were by 21 % and 11 % lower, respectively, than the values determined by PET CT (p CT and PET MR were minor, but statistically significant. Nevertheless, a more detailed study of the quantitative accuracy of PET MR and the factors governing it is needed to ultimately assess its accuracy in measuring tissue tracer concentrations. (orig.)

MRI-assisted PET motion correction for neurologic studies in an integrated MR-PET scanner.

Science.gov (United States)

Catana, Ciprian; Benner, Thomas; van der Kouwe, Andre; Byars, Larry; Hamm, Michael; Chonde, Daniel B; Michel, Christian J; El Fakhri, Georges; Schmand, Matthias; Sorensen, A Gregory

2011-01-01

Head motion is difficult to avoid in long PET studies, degrading the image quality and offsetting the benefit of using a high-resolution scanner. As a potential solution in an integrated MR-PET scanner, the simultaneously acquired MRI data can be used for motion tracking. In this work, a novel algorithm for data processing and rigid-body motion correction (MC) for the MRI-compatible BrainPET prototype scanner is described, and proof-of-principle phantom and human studies are presented. To account for motion, the PET prompt and random coincidences and sensitivity data for postnormalization were processed in the line-of-response (LOR) space according to the MRI-derived motion estimates. The processing time on the standard BrainPET workstation is approximately 16 s for each motion estimate. After rebinning in the sinogram space, the motion corrected data were summed, and the PET volume was reconstructed using the attenuation and scatter sinograms in the reference position. The accuracy of the MC algorithm was first tested using a Hoffman phantom. Next, human volunteer studies were performed, and motion estimates were obtained using 2 high-temporal-resolution MRI-based motion-tracking techniques. After accounting for the misalignment between the 2 scanners, perfectly coregistered MRI and PET volumes were reproducibly obtained. The MRI output gates inserted into the PET list-mode allow the temporal correlation of the 2 datasets within 0.2 ms. The Hoffman phantom volume reconstructed by processing the PET data in the LOR space was similar to the one obtained by processing the data using the standard methods and applying the MC in the image space, demonstrating the quantitative accuracy of the procedure. In human volunteer studies, motion estimates were obtained from echo planar imaging and cloverleaf navigator sequences every 3 s and 20 ms, respectively. Motion-deblurred PET images, with excellent delineation of specific brain structures, were obtained using these 2 MRI

Material and Structural Performance Evaluations of Hwangtoh Admixtures and Recycled PET Fiber-Added Eco-Friendly Concrete for CO2 Emission Reduction

Directory of Open Access Journals (Sweden)

Bon-Min Koo

2014-08-01

Full Text Available In order to reduce carbon dioxide (CO2 emissions and produce an eco-friendly construction material, a type of concrete that uses a minimal amount of cement, yet still retains equivalent properties to ordinary cement concrete, has been developed and studied all over the world. Hwangtoh, a type of red clay broadly deposited around the world, has traditionally been considered an eco-friendly construction material, with bonus advantages of having health and cost benefits. Presently, Hwangtoh is not commonly used as a modern construction material due to properties such as low strength and high rates of shrinkage cracking. Recent studies, however, have shown that Hwangtoh can be used as a mineral admixture to improve the strength of concrete. In addition, polyethylene terephthalate (PET fibers recycled from PET bottle waste can be used to control shrinkage cracks in Hwangtoh concrete. Therefore, in this study, performance verification is conducted on newly developed Hwangtoh concrete mixed with short recycled PET fibers. The results show that Hwangtoh concrete has compressive strength, elastic modulus, and pH properties that are similar to these features in ordinary cement concrete. The properties of carbonation depth and creep strain of Hwangtoh concrete, however, are larger and smaller, respectively, than in ordinary cement concrete. According to flexural tests, reinforced concrete (RC specimens cast with Hwangtoh admixtures (with and without PET fibers possess similar or better capacities than ordinary RC specimens. The addition of PET fibers significantly improves the structural ductility of RC specimens under normal environmental conditions. However, the implementations of the concrete in aggressive environment must be carefully considered, since a previous study result indicates degradation of its durability performance in aggressive environments, such as seawater [1]. The results of this study validate the possibility of using eco

Material and Structural Performance Evaluations of Hwangtoh Admixtures and Recycled PET Fiber-Added Eco-Friendly Concrete for CO2 Emission Reduction

Science.gov (United States)

Koo, Bon-Min; Kim, Jang-Ho Jay; Kim, Sung-Bae; Mun, Sungho

2014-01-01

In order to reduce carbon dioxide (CO2) emissions and produce an eco-friendly construction material, a type of concrete that uses a minimal amount of cement, yet still retains equivalent properties to ordinary cement concrete, has been developed and studied all over the world. Hwangtoh, a type of red clay broadly deposited around the world, has traditionally been considered an eco-friendly construction material, with bonus advantages of having health and cost benefits. Presently, Hwangtoh is not commonly used as a modern construction material due to properties such as low strength and high rates of shrinkage cracking. Recent studies, however, have shown that Hwangtoh can be used as a mineral admixture to improve the strength of concrete. In addition, polyethylene terephthalate (PET) fibers recycled from PET bottle waste can be used to control shrinkage cracks in Hwangtoh concrete. Therefore, in this study, performance verification is conducted on newly developed Hwangtoh concrete mixed with short recycled PET fibers. The results show that Hwangtoh concrete has compressive strength, elastic modulus, and pH properties that are similar to these features in ordinary cement concrete. The properties of carbonation depth and creep strain of Hwangtoh concrete, however, are larger and smaller, respectively, than in ordinary cement concrete. According to flexural tests, reinforced concrete (RC) specimens cast with Hwangtoh admixtures (with and without PET fibers) possess similar or better capacities than ordinary RC specimens. The addition of PET fibers significantly improves the structural ductility of RC specimens under normal environmental conditions. However, the implementations of the concrete in aggressive environment must be carefully considered, since a previous study result indicates degradation of its durability performance in aggressive environments, such as seawater [1]. The results of this study validate the possibility of using eco-friendly Hwangtoh concrete

Status report of the baseline collimation system of CLIC. Part I

CERN Document Server

Resta-Lopez, J.; Dalena, B.; Fernandez-Hernando, J.L.; Jackson, F.; Schulte, D.; Seryi, A.; Tomas, R.

2011-01-01

Important efforts have recently been dedicated to the characterisation and improvement of the design of the post-linac collimation system of the Compact Linear Collider (CLIC). This system consists of two sections: one dedicated to the collimation of off-energy particles and another one for betatron collimation. The energy collimation system is further conceived as protection system against damage by errant beams. In this respect, special attention is paid to the optimisation of the energy collimator design. The material and the physical parameters of the energy collimators are selected to withstand the impact of an entire bunch train. Concerning the betatron collimation section, different aspects of the design have been optimised: the transverse collimation depths have been recalculated in order to reduce the collimator wakefield effects while maintaining a good efficiency in cleaning the undesired beam halo; the geometric design of the spoilers has been reviewed to minimise wakefields; in addition, the opti...

Status report of the baseline collimation system of CLIC. Part II

CERN Document Server

Resta-Lopez, J.; Dalena, B.; Fernandez-Hernando, J.L.; Jackson, F.; Schulte, D.; Seryi, A.; Tomas, R.

2011-01-01

Important efforts have recently been dedicated to the characterisation and improvement of the design of the post-linac collimation system of the Compact Linear Collider (CLIC). This system consists of two sections: one dedicated to the collimation of off-energy particles and another one for betatron collimation. The energy collimation system is further conceived as protection system against damage by errant beams. In this respect, special attention is paid to the optimisation of the energy collimator design. The material and the physical parameters of the energy collimators are selected to withstand the impact of an entire bunch train. Concerning the betatron collimation section, different aspects of the design have been optimised: the transverse collimation depths have been recalculated in order to reduce the collimator wakefield effects while maintaining a good efficiency in cleaning the undesired beam halo; the geometric design of the spoilers has been reviewed to minimise wakefields; in addition, the opti...

Properties of tribology for Si implanted PET

International Nuclear Information System (INIS)

Wu Yuguang; Zhang Tonghe; Zhang Xu; Liu Andong; Xie Mengxia; Zhang Aimin; Chen Jianmin

2002-01-01

Polyethylene terephthalate (PET) has been modified with Si ions from a metal vapor arc source (MEVVA). After implantation, the surface structure has been greatly changed. The experimental results of infrared absorption indicated that the particles are referred to rich carbon and SiC particles. The PET has been strengthened by these dispersed particles. The measurement results using nanometer hardness tester reveal that both surface hardness and modulus increase obviously. Therefore the surface wear resistance improved extremely. Finally the modification mechanism of Si implanted PET was discussed

Side-by-side reading of PET and CT scans in oncology: Which patients might profit from integrated PET/CT?

International Nuclear Information System (INIS)

Reinartz, Patrick; Wieres, Franz-Josef; Schneider, Wolfram; Schur, Alexander; Buell, Ulrich

2004-01-01

Most early publications on integrated positron emission tomography/computed tomography (PET/CT) devices have reported the new scanner generation to be superior to conventional PET. However, few of these studies have analysed the situation where, in addition to PET, a current CT scan is available for side-by-side viewing. This fact is important, because combined PET/CT or a software-based fusion of the two modalities may improve diagnosis only in cases where side-by-side reading of PET and CT data does not lead to a definitive diagnosis. The aim of this study was to analyse which patients will profit from integrated PET/CT in terms of lesion characterization. A total of 328 consecutively admitted patients referred for PET in whom a current CT scan was available were included in the study. The localization of all pathological PET lesions, as well as possible infiltration of adjacent anatomical structures, was assessed. Of 467 pathological lesions, 94.0% were correctly assessed with respect to localization and infiltration by either conventional PET alone (51.6%) or combined reading of PET and the already existing CT scans (42.4%). Hence, in only 6.0% of all lesions, affecting 6.7% of all patients, could evaluation have profited from integrated PET/CT. We conclude that side-by-side viewing of PET and CT scans is essential, as in 42.4% of all cases, combined viewing was important for a correct diagnosis in our series. In up to 6.7% of patients, integrated PET/CT might have given additional information, so that in nearly 50% of patients some form of combined viewing of PET and CT data is needed for accurate lesion characterization. (orig.)

Detection of Cancer with PET and PET/CT in Asymptomatic Volunteers

International Nuclear Information System (INIS)

Chung, Ji In; Choi, Joon Young; Lee, Kyung Han; Kim, Byung Tae; Choi, Yoon Ho; Cho, Han Byoul; Shim, Jae Yong

2009-01-01

We retrospectively investigated the diagnostic performance of 18 F-fluorodeoxyglucose positron emission tomography (PET) and PET/CT for cancer detection in asymptomatic health-check examinees. This study consisted of 5091 PET or PET/CT conducted as part of annual health examination at one hospital from March 1998 to February 2008. To find the incidence of cancers, medical records of the subjects were thoroughly reviewed for a follow-up period of one year. The patterns of formal readings of PET and PET/CT were analyzed to assess the sensitivity and specificity for cancer detection. The histopathology and stage of the cancers were evaluated in relation to the results of PET. Eighty-six cancers (1.7%) were diagnosed within one year after PET or PET/CT. When PET and PET/CT results were combined, the sensitivity was 48.8% and specificity was 81.1% for cancer detection. PET only had a sensitivity of 46.2% and a specificity of 81.4%, and PET/CT only had a sensitivity of 75.0% and a specificity of 78.5% respectively. There were no significant differences in cancer site, stage and histopathology between PET positive and PET negative cancers. In 19.3% of formal readings of PET and PET/CT, further evaluation to exclude malignancy or significant disease was recommended. Head and neck area and upper gastrointestinal tract were commonly recommended sites for further evaluation. PET and PET/CT showed moderate performance for detecting cancers in asymptomatic adults in this study. More experience and further investigation are needed to overcome limitations of PET and PET/CT for cancer screening

Development of a PET Insert for simultaneously small animal PET/MRI

Energy Technology Data Exchange (ETDEWEB)

Wang, Yingjie; Zhang, Zhiming; Li, Daowu; Liu, Shuangquan; Wang, Peilin; Feng, Baotong; Chai, Pei; Wei, Long [Division of Nuclear Technology and Applications, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049 (China); Beijing Engineering Research Center of Radiographic Techniques and Equipment, Beijing, 100049 (China)

2015-05-18

PET/MR is a new multi-modality imaging system which provide both structural and functional information with good soft tissue imaging ability and no ionizing radiation. In recent years, PET/MR is under major progress because of the development of silicon photomultipliers (SiPM). The goal of this study is to develop a MRI compatible PET insert based on SiPM and LYSO scintillator. The PET system was constituted by the detector ring, electronics and software. The detector ring consists of 16 detector module. The inner diameter of the ring was 151 mm, the external diameter was 216 mm, which was big enough for small animal research, e.g. rat, rabbit and tupaia. The sensor of each module was 2*2 SensL SPMArraySL, coupled with an array of 14 x 14 LYSO crystals, each crystal measuring 2 mm x 2 mm 10 mm. The detector was encapsulated in a copper box for light and magnetic shielding. Resister charge multiplexing circuit was used in the front end electronics. Each detector output 8X and 8Y position signals. One summed timing signal was extracted from the common cathode of all 64 channels. All these signals were transmitted to digital electronic board by a 3 m long coaxial cable from inside of the MR to the outside. Each digital electronic board handled 8 detector modules based on FPGA to obtain the timing, position and energy information of a single event. And then these single events were sent to the coincidence processing board to produce coincidence packets which are prepared for further processing. A 0.2mCi 68Ge line source was used to do the preliminary imaging test. The image was reconstructed by 3D-OSEM algorithm. The initial result proved the system to be feasible as a PET. FDG phantom imaging and simultaneous PET/MR imaging are in progress.

Physics performances for Scalar Electron, Scalar Muon and Scalar Neutrino searches at 3 TeV and 1.4 TeV at CLIC

CERN Document Server

Battaglia, M.; Marshall, J.S.; Poss, S.; Sailer, A.; Thomson, M.; van der Kraaij, E.

2013-01-01

The determination of scalar lepton and gaugino masses is an important part of the programme of spectroscopic studies of Supersymmetry at a high energy e+e- linear collider. In this article we present results of a study of the processes: e+e- -> eR eR -> e+e- chi0 chi, e+e- -> muR muR -> mu mu- chi0 chi0, e+e- -> eL eL -> e e chi0 chi0 and e+e- -> snu_e snu_e -> e e chi+ chi-in two Supersymmetric benchmark scenarios at 3 TeV and 1.4 TeV at CLIC. We characterize the detector performance, lepton energy resolution and boson mass resolution. We report the accuracy of the production cross section measurements and the eR muR, snu_e, chi+ and chi0 mass determination, estimate the systematic errors affecting the mass measurement and discuss the requirements on the detector time stamping capability and beam polarization. The analysis accounts for the CLIC beam energy spectrum and the dominant beam-induced background. The detector performances are incorporated by full simulation and reconstruction of the events within t...

Adhesion of nitrile rubber to UV-assisted surface chemical modified PET fabric, part II: Interfacial characterization of MDI grafted PET

Science.gov (United States)

Razavizadeh, Mahmoud; Jamshidi, Masoud

2016-08-01

Fiber to rubber adhesion is an important subject in rubber industry. It is well known that surface treatment (i.e. physical, mechanical and chemical) is an effective method to improve interfacial bonding of fibers and/or fabrics to rubbers. UV irradiation is an effective method which has been used to increase fabric-rubber interfacial interactions. In this research UV assisted chemical modification of PET fabrics was used to increase PET to nitrile rubber (NBR) adhesion. Nitrile rubber is a perfect selection as fuel and oil resistant rubber. However it has weak bonding to PET fabric. For this purpose PET fabric was carboxylated under UV irradiation and then methylenediphenyl diisocyanate (MDI) was grafted on carboxylated PET. The chemical composition of the fabric before and after surface treatment was investigated by X-ray photoelectron spectroscopy (XPS). The sectional morphology of the experimental PET fibers and the interface between rubber compound and PET fabric was studied using scanning electron microscope (SEM). The morphology and structure of the product were analyzed by an energy dispersive X-ray spectrometer (EDX). FTIR-ATR and H NMR analysis were used to assess surface modifications on the PET irradiated fabrics.

MR-assisted PET Motion Correction for eurological Studies in an Integrated MR-PET Scanner

Science.gov (United States)

Catana, Ciprian; Benner, Thomas; van der Kouwe, Andre; Byars, Larry; Hamm, Michael; Chonde, Daniel B.; Michel, Christian J.; El Fakhri, Georges; Schmand, Matthias; Sorensen, A. Gregory

2011-01-01

Head motion is difficult to avoid in long PET studies, degrading the image quality and offsetting the benefit of using a high-resolution scanner. As a potential solution in an integrated MR-PET scanner, the simultaneously acquired MR data can be used for motion tracking. In this work, a novel data processing and rigid-body motion correction (MC) algorithm for the MR-compatible BrainPET prototype scanner is described and proof-of-principle phantom and human studies are presented. Methods To account for motion, the PET prompts and randoms coincidences as well as the sensitivity data are processed in the line or response (LOR) space according to the MR-derived motion estimates. After sinogram space rebinning, the corrected data are summed and the motion corrected PET volume is reconstructed from these sinograms and the attenuation and scatter sinograms in the reference position. The accuracy of the MC algorithm was first tested using a Hoffman phantom. Next, human volunteer studies were performed and motion estimates were obtained using two high temporal resolution MR-based motion tracking techniques. Results After accounting for the physical mismatch between the two scanners, perfectly co-registered MR and PET volumes are reproducibly obtained. The MR output gates inserted in to the PET list-mode allow the temporal correlation of the two data sets within 0.2 s. The Hoffman phantom volume reconstructed processing the PET data in the LOR space was similar to the one obtained processing the data using the standard methods and applying the MC in the image space, demonstrating the quantitative accuracy of the novel MC algorithm. In human volunteer studies, motion estimates were obtained from echo planar imaging and cloverleaf navigator sequences every 3 seconds and 20 ms, respectively. Substantially improved PET images with excellent delineation of specific brain structures were obtained after applying the MC using these MR-based estimates. Conclusion A novel MR-based MC

The influence of the structures and compounds of DLC coatings on the barrier properties of PET bottles

International Nuclear Information System (INIS)

Li, Yang; Zhen-Duo, Wang; Shou-Ye, Zhang; Li-Zhen, Yang; Qiang, Chen

2009-01-01

To reduce the oxygen transmission rate through a polyethylene terephthalate (PET) bottle (an organic plastic) diamond-like carbon (DLC) coatings on the inner surface of the PET bottle were deposited by radio frequency plasma-enhanced chemical vapour deposition (RF-PECVD) technology with C 2 H 2 as the source of carbon and Ar as the diluted gas. As the barrier layer to humidity and gas permeation, this paper analyses the DLC film structure, composition, morphology and barrier properties by Fourier transform infrared, atomic force microscopy, scanning electron microscopy and oxygen transmission rate in detail. From the spectrum, it is found that the DLC film mainly consists of sp 3 bonds. The barrier property of the films is significantly relevant to the sp 3 bond concentration in the coating, the film thickness and morphology. Additionally, it is found that DLC film deposited in an inductively coupled plasma enhanced capacitively coupled plasma source shows a compact, homogeneous and crack-free surface, which is beneficial for a good gas barrier property in PET bottles. (fluids, plasmas and electric discharges)

PET

DEFF Research Database (Denmark)

Mariager, Rasmus Mølgaard; Schmidt, Regin; Heiberg, Morten Rievers

PET handler om den hemmelige tjenestes arbejde under den kolde krig 1945-1989. Her fortæller Regin Schmidt, Rasmus Mariager og Morten Heiberg om de mest dramatiske og interessante sager fra PET's arkiv. PET er på flere måder en udemokratisk institution, der er sat til at vogte over demokratiet....... Dens virksomhed er skjult for offentligheden, den overvåger borgernes aktiviteter, og den registrerer følsomme personoplysninger. Historien om PET rejser spørgsmålet om, hvad man skal gøre, når befolkningen i et demokrati er kritisk indstillet over for overvågningen af lovlige politiske aktiviteter......, mens myndighederne mener, at det er nødvendigt for at beskytte demokratiet. PET er på en gang en fortælling om konkrete aktioner og begivenheder i PET's arbejde og et stykke Danmarkshistorie. Det handler om overvågning, spioner, politisk ekstremisme og international terrorisme.  ...

Clinical usefulness of PET in the management of oral cancer. Comparison between FDG-PET and MET-PET

International Nuclear Information System (INIS)

Kitagawa, Yoshimasa; Saitoh, Masaaki; Nakamura, Mikiko

2007-01-01

Inductive chemoradiotherapy has played an important role in preserving organs and functions in patients with oral squamous cell carcinoma (SCC). To determine whether a reduced form of surgery should be performed after chemoradiotherapy, accurate evaluation of residual tumor cells is essential. We investigated the clinical value of positron emission tomography with 18 F labeled fluorodeoxyglucose (FDG-PET) in the management of oral SCCs. Forty-five patients underwent two FDG-PET studies, one prior to and one at 6 weeks after the chemoradiotherapy. Pretreatment FDG-PET was useful in predicting the response to treatment. Posttreatment FDG-PET could evaluate residual viable cells and prognosis. Organ preservation may be feasible based on PET evaluation. Hence FDG-PET is a valuable tool in the treatment of oral cancer. 11 C-Methionine (MET) is another promising tracer for PET that can be used to assess metabolic demand for amino acids in cancer cells. A MET-PET and FDG-PET study was performed during the same period to investigate diagnostic accuracy in 40 oral malignancies. Sensitivity and positive predictive value of MET-PET were 95% and 100%, respectively, and were comparable with those of FDG-PET. Further study is required to determine the diagnostic significance of MET-PET in evaluating response to chemoradiotherapy. (author)

Development of PET/MRI with insertable PET for simultaneous PET and MR imaging of human brain

International Nuclear Information System (INIS)

Jung, Jin Ho; Choi, Yong; Jung, Jiwoong; Kim, Sangsu; Lim, Hyun Keong; Im, Ki Chun; Oh, Chang Hyun; Park, Hyun-wook; Kim, Kyung Min; Kim, Jong Guk

2015-01-01

Purpose: The purpose of this study was to develop a dual-modality positron emission tomography (PET)/magnetic resonance imaging (MRI) with insertable PET for simultaneous PET and MR imaging of the human brain. Methods: The PET detector block was composed of a 4 × 4 matrix of detector modules, each consisting of a 4 × 4 array LYSO coupled to a 4 × 4 Geiger-mode avalanche photodiode (GAPD) array. The PET insert consisted of 18 detector blocks, circularly mounted on a custom-made plastic base to form a ring with an inner diameter of 390 mm and axial length of 60 mm. The PET gantry was shielded with gold-plated conductive fabric tapes with a thickness of 0.1 mm. The charge signals of PET detector transferred via 4 m long flat cables were fed into the position decoder circuit. The flat cables were shielded with a mesh-type aluminum sheet with a thickness of 0.24 mm. The position decoder circuit and field programmable gate array-embedded DAQ modules were enclosed in an aluminum box with a thickness of 10 mm and located at the rear of the MR bore inside the MRI room. A 3-T human MRI system with a Larmor frequency of 123.7 MHz and inner bore diameter of 60 cm was used as the PET/MRI hybrid system. A custom-made radio frequency (RF) coil with an inner diameter of 25 cm was fabricated. The PET was positioned between gradient and the RF coils. PET performance was measured outside and inside the MRI scanner using echo planar imaging, spin echo, turbo spin echo, and gradient echo sequences. MRI performance was also evaluated with and without the PET insert. The stability of the newly developed PET insert was evaluated and simultaneous PET and MR images of a brain phantom were acquired. Results: No significant degradation of the PET performance caused by MR was observed when the PET was operated using various MR imaging sequences. The signal-to-noise ratio of MR images was slightly degraded due to the PET insert installed inside the MR bore while the homogeneity was

Development of PET/MRI with insertable PET for simultaneous PET and MR imaging of human brain

Energy Technology Data Exchange (ETDEWEB)

Jung, Jin Ho; Choi, Yong, E-mail: ychoi.image@gmail.com; Jung, Jiwoong; Kim, Sangsu; Lim, Hyun Keong; Im, Ki Chun [Department of Electronic Engineering, Sogang University, 35 Baekbeom-ro, Mapo-gu, Seoul 121-742 (Korea, Republic of); Oh, Chang Hyun; Park, Hyun-wook [Department of Electrical Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Kim, Kyung Min; Kim, Jong Guk [Korea Institute of Radiological and Medical Science, 75 Nowon-ro, Nowon-gu, Seoul 139-709 (Korea, Republic of)

2015-05-15

Purpose: The purpose of this study was to develop a dual-modality positron emission tomography (PET)/magnetic resonance imaging (MRI) with insertable PET for simultaneous PET and MR imaging of the human brain. Methods: The PET detector block was composed of a 4 × 4 matrix of detector modules, each consisting of a 4 × 4 array LYSO coupled to a 4 × 4 Geiger-mode avalanche photodiode (GAPD) array. The PET insert consisted of 18 detector blocks, circularly mounted on a custom-made plastic base to form a ring with an inner diameter of 390 mm and axial length of 60 mm. The PET gantry was shielded with gold-plated conductive fabric tapes with a thickness of 0.1 mm. The charge signals of PET detector transferred via 4 m long flat cables were fed into the position decoder circuit. The flat cables were shielded with a mesh-type aluminum sheet with a thickness of 0.24 mm. The position decoder circuit and field programmable gate array-embedded DAQ modules were enclosed in an aluminum box with a thickness of 10 mm and located at the rear of the MR bore inside the MRI room. A 3-T human MRI system with a Larmor frequency of 123.7 MHz and inner bore diameter of 60 cm was used as the PET/MRI hybrid system. A custom-made radio frequency (RF) coil with an inner diameter of 25 cm was fabricated. The PET was positioned between gradient and the RF coils. PET performance was measured outside and inside the MRI scanner using echo planar imaging, spin echo, turbo spin echo, and gradient echo sequences. MRI performance was also evaluated with and without the PET insert. The stability of the newly developed PET insert was evaluated and simultaneous PET and MR images of a brain phantom were acquired. Results: No significant degradation of the PET performance caused by MR was observed when the PET was operated using various MR imaging sequences. The signal-to-noise ratio of MR images was slightly degraded due to the PET insert installed inside the MR bore while the homogeneity was

Evaluation of attenuation correction in cardiac PET using PET/MR.

Science.gov (United States)

Lau, Jeffrey M C; Laforest, R; Sotoudeh, H; Nie, X; Sharma, S; McConathy, J; Novak, E; Priatna, A; Gropler, R J; Woodard, P K

2017-06-01

Simultaneous acquisition Positron emission tomography/magnetic resonance (PET/MR) is a new technology that has potential as a tool both in research and clinical diagnosis. However, cardiac PET acquisition has not yet been validated using MR imaging for attenuation correction (AC). The goal of this study is to evaluate the feasibility of PET imaging using a standard 2-point Dixon volume interpolated breathhold examination (VIBE) MR sequence for AC. Evaluation was performed in both phantom and patient data. A chest phantom containing heart, lungs, and a lesion insert was scanned by both PET/MR and PET/CT. In addition, 30 patients underwent whole-body 18 F-fluorodeoxyglucose PET/CT followed by simultaneous cardiac PET/MR. Phantom study showed 3% reduction of activity values in the myocardium due to the non-inclusion of the phased array coil in the AC. In patient scans, average standardized uptake values (SUVs) obtained by PET/CT and PET/MR showed no significant difference (n = 30, 4.6 ± 3.5 vs 4.7 ± 2.8, P = 0.47). There was excellent per patient correlation between the values acquired by PET/CT and PET/MR (R 2  = 0.97). Myocardial SUVs PET imaging using MR for AC shows excellent correlation with myocardial SUVs obtained by standard PET/CT imaging. The 2-point Dixon VIBE MR technique can be used for AC in simultaneous PET/MR data acquisition.

18F-FDG PET and PET/CT in Burkitt's lymphoma

International Nuclear Information System (INIS)

Karantanis, Dimitrios; Durski, Jolanta M.; Lowe, Val J.; Nathan, Mark A.; Mullan, Brian P.; Georgiou, Evangelos; Johnston, Patrick B.; Wiseman, Gregory A.

2010-01-01

Objective: To explore the value of 18 F fluorodeoxy-glucose (FDG) positron emission tomography (PET) in Burkitt's lymphoma. Methods: All Burkitt's lymphoma patients referred for FDG PET or FDG PET/computed tomography (CT) exams at our institution from June 2003 to June 2006 were included. Selected patients were followed and clinical information was reviewed retrospectively. Results from FDG PET-PET/CT, as blindly reviewed by a consensus of two experienced readers, were compared with the status of the disease as determined by other laboratory, clinical and imaging exams and clinical follow-up. FDG PET-PET/CT results were classified as true positive or negative and false positive or negative. The degree of FDG uptake in the positive lesions was semiquantified as maximum standard uptake value (SUVmax). Results: Fifty-seven FDG PET-PET/CT exams were done in 15 patients. Seven exams were done for initial staging, 8 during and 14 after the completion of therapy, and 28 for disease surveillance. For nodal disease FDG PET-PET/CT was true positive in 8, true negative in 47 and false positive in 2 exams (sensitivity 100%, specificity 96%). For extranodal disease FDG PET-PET/CT was true positive in 6, true negative in 48 and false positive in 3 exams (sensitivity 100%, specificity 94%). The mean SUVmax for the positive nodal lesions was 15.7 (range 6.9-21.7, median 18.5) and for extranodal lesions was 14.2 (range 6.2-24.3, median 12.4). Conclusions: FDG PET-PET/CT is sensitive for the detection of viable disease in Burkitt's lymphoma. Affected areas demonstrated high degree of uptake that was reversible upon successful implementation of treatment.

PET or PET-CT with cancer screening

International Nuclear Information System (INIS)

Wang Taisong; Zhao Jinhua; Song Jianhua

2007-01-01

At present, cancer screening remains a lot of debate in contemporary medical practice. Many constitutes have done a lot of experiments in cancer screening. The same version is that recommendations and decisions regarding cancer screening should be based on reliable data, not self- approbation. Now, some institutes advocate 18 F-FDG PET or 18 F-FDG PET-CT for cancer screening, here, discussed status quo, potential financial, radiation safety and statistical data in 18 F-FDG PET or 18 F-FDG PET- CT cancer screening. (authors)

PET / MRI vs. PET / CT. Indications Oncology

International Nuclear Information System (INIS)

Oliva González, Juan P.

2016-01-01

Hybrid techniques in Nuclear Medicine is currently a field in full development for diagnosis and treatment of various medical conditions. With the recent advent of PET / MRI much it speculated about whether or not it is superior to PET / CT especially in oncology. The Conference seeks to clarify this situation by dealing issues such as: State of the art technology PET / MRI; Indications Oncology; Some clinical cases. It concludes by explaining the oncological indications of both the real and current situation of the PET / MRI. (author)

Application of PET and PET/CT imaging for cancer screening

International Nuclear Information System (INIS)

Chen Yenkung; Hu Fenglan; Shen Yehyou; Liao, A.C.; Hung, T.Z.; Su, Chentau; Chen Liangkuang

2004-01-01

The aim of this study was to evaluate the potential application of 18F-fluorodeoxyglucose (FDG) Positron Emission Tomography (PET) and PET/CT for cancer screening in asymptomatic individuals. Methods: The subjects consisted of 3631 physical check up examinees (1947 men, 1684 women; mean age ±SD, 52.1±8.2 y) with non-specific medical histories. Whole-body FDG PET (or PET/CT), ultrasound and tumor markers were performed on all patients. Focal hypermetabolic areas with intensities equal to or exceeding the level of FDG uptake in the brain and bladder were considered abnormal and interpreted as neoplasia. Follow-up periods were longer than one year. Results: Among the 3631 FDG PET (including 1687 PET/CT), ultrasound and tumor markers examinations, malignant tumors were discovered in 47 examinees (1.29%). PET findings were true-positive in 38 of the 47 cancers (80.9%). In addition, 32 of the 47 cancers were performed with the PET-CT scan. PET detected cancer lesions in 28 of the 32 examinees. However, the CT detected cancer lesions in only 15 of 32 examinees. Conclusion: The sensitivity of FDG PET in the detection of a wide variety of cancers is high. Most cancer can be detected with FDG PET in a resectable stage. CT of the PET/CT for localization and characteristics of the lesion shows an increased specificity of the PET scan. Using ultrasound and tumor markers may complement the PET scan in cancer screening for hepatic and urologic neoplasms. (authors)

PET/CT in lymphoma patients; PET-CT bei Lymphompatienten

Energy Technology Data Exchange (ETDEWEB)

Steinert, H.C. [Universitaetsspital Zuerich, Klinik und Poliklinik fuer Nuklearmedizin (Switzerland)

2004-11-01

First results of PET/CT in Hodgkin's disease (HD) and aggressive non-Hodgkin's lymphoma (NHL) are reported. From March 2001 to August 2004 822 PET/CT were performed at our clinic in lymphoma patients for primary staging, restaging after therapy, and diagnosis of recurrence. For coregistration non contrast-enhanced low-dose CT were used. Due to the exact anatomic localization of {sup 18}F-FDG accumulating lesions equivocal or false positive PET findings are avoided. In comparison to contrast enhanced CT, PET/CT has a higher sensitivity and specificity in patients with HD and aggressive NHL. Integration of PET/CT in treatment planning of radiation therapy optimizes the field volume. Even in the initial phase of clinical evaluation, PET/CT has proven useful in staging and restaging of lymphoma. The exact anatomic localization of the PET findings is essential for a precise report, for treatment planning of radiation therapy, and for planning surgical biopsy. (orig.) [German] Erste Ergebnisse der PET-CT bei Morbus Hodgkin (HD) und den aggressiven Non-Hodgkin-Lymphomen (NHL) werden beschrieben. Von Maerz 2001 bis August 2004 wurden 822 PET-CT bei Lymphompatienten zum primaeren Staging, zum Restaging nach Therapie und zur Rezidivdiagnostik an unserer Klinik durchgefuehrt. Fuer die Koregistration wurde ein Low-dose-CT ohne i.v.-Kontrastmittel verwendet. Durch die exakte anatomische Zuordnung der {sup 18}F-FDG aufnehmenden Laesionen wurden unklare oder falsch-positive PET-Befunde vermieden. Die PET-CT erzielte im Vergleich zur KM-verstaerkten CT eine hoehere Sensitivitaet und Spezifitaet bei Patienten mit HD und aggressiven NHL. Die Integration der PET-CT in die Planung der Strahlentherapie fuehrte zu einer Optimierung der Feldgrenzen. Die PET-CT hat sich bereits in der Phase der initialen klinischen Evaluation als wertvoll beim Staging und Restaging von Lymphomen erwiesen. Die exakte anatomische Zuordnung der PET-Informationen ist fuer eine sichere Befundung

Current status and future perspective of PET

International Nuclear Information System (INIS)

Lee, Myung Chul

2002-01-01

Positron Emission Tomography (PET) is a nuclear medicine imaging modality that consists of systemic administration to a subject of a radiopharmaceutical labeled with a positron-emitting radionuclide. Following administration, its distribution in the organ or structure under study can be assessed as a function of time and space by (1) detecting the annihilation radiation resulting from the interaction of the positrons with matter, and (2) reconstructing the distribution of the radioactivity from a series of that used in computed tomography (CT). The nuclides most generally exhibit chemical properties that render them particularly desirable in physiological studies. The radionuclides most widely used in PET are F-18, C-11, O-15 and N-13. Regarding to the number of the current PET Centers worldwide (based on ICP data), more than 300 PET Centers were in operation in 2000. The use of PET technology grew rapidly compared to that in 1992 and 1996, particularly in the USA, which demonstrates a three-fold rise in PET installations. In 2001, 194 PET Centers were operating in the USA. In 1994, two clinical and research-oriented PET Centers at Seoul National University Hospital and Samsung Medical Center, was established as the first dedicated PET and Cyclotron machines in Korea, followed by two more PET facilities at the Korea Cancer Center Hospital, Ajou Medical Center, Yonsei University Medical Center, National Cancer Center and established their PET Center. Catholic Medical School and Pusan National University Hospital have finalized a plan to install PET machine in 2002, which results in total of nine PET Centers in Korea. Considering annual trends of PET application in four major PET centers in Korea in Asan Medical Center recent six years (from 1995 to 2000), a total of 11,564 patients have been studied every year and the number of PET studies has shown steep growth year upon year. We had, 1,020 PET patients in 1995. This number increased to 1,196, 1,756, 2,379, 3

Characterization of a PET-NEMA/IEC body phantom for quality control tests of PET/CT equipment

International Nuclear Information System (INIS)

Oliveira, Cassio M.; Vieira, Igor F.; Lima, Fernando R.A.; Sa, Lidia V. de

2011-01-01

The Brazilian Sanitary Agency from Ministry of Health requires that all PET/CT equipment must undergo minimal quality control tests using manufacturer simulators. The PET-NEMA/IEC body phantom is recommended by the IEC and NEMA to perform acceptance testing and quality control in PET/CT equipment according to specific protocols. It is essential that all simulator components (spheres and body) are properly characterized in relation to their size and internal structure volumes, since they are used to calculate the overall activity concentration and the total weight. The objective of this work was characterize a PET-NEMA/IEC body phantom for the true reconstruction in computational modeling and correct analysis of experimental results. The simulator is basically composed of three structures: the body (simulating a portion of the chest), an inner cylinder (simulating the lung tissue) and a top cover in which are coupled spheres of different sizes simulating 'hot' (tumors) and cold lesions. The spheres were evaluated in terms of volume. The same evaluations were performed with the body of the simulator and the inner cylinder, beyond of analysis of their weights (filled with water) and wall thickness. The data showed that the total weight of the simulator with all its internal structures is 12.5 kg and the volume of the 'hot' and 'cold' spheres are approximately equal to those presented by the manufacturer. The inner cylinder volume showed a significant difference between the measured and the presented in the manual. The results were used for reconstruction of the simulator in computational modeling using the code GATE. (author)

Do carotid MR surface coils affect PET quantification in PET/MR imaging?

International Nuclear Information System (INIS)

Willemink, Martin J; Eldib, Mootaz; Leiner, Tim; Fayad, Zahi A; Mani, Venkatesh

2015-01-01

To evaluate the effect of surface coils for carotid MR imaging on PET quantification in a clinical simultaneous whole-body PET/MR scanner. A cylindrical phantom was filled with a homogeneous 2L water-FDG mixture at a starting dose of 301.2MBq. Clinical PET/MR and PET/CT systems were used to acquire PET-data without a coil (reference standard) and with two carotid MRI coils (Siemens Special Purpose 8-Channel and Machnet 4-Channel Phased Array). PET-signal attenuation was evaluated with Osirix using 51 (PET/MR) and 37 (PET/CT) circular ROIs. Mean and maximum standardized uptake values (SUVs) were quantified for each ROI. Furthermore, SUVs of PET/MR and PET/CT were compared. For validation, a patient was scanned with an injected dose of 407.7MBq on both a PET/CT and a PET/MR system without a coil and with both coils. PET/MR underestimations were -2.2% (Siemens) and -7.8% (Machnet) for SUVmean, and -1.2% (Siemens) and -3.3% (Machnet) for SUVmax, respectively. For PET/CT, underestimations were -1.3% (Siemens) and -1.4% (Machnet) for SUVmean and -0.5% (both Siemens and Machnet) for SUVmax, respectively using no coil data as reference. Except for PET/CT SUVmax values all differences were significant. SUVs differed significantly between PET/MR and PET/CT with SUVmean values of 0.51-0.55 for PET/MR and 0.68-0.69 for PET/CT, respectively. The patient examination showed that median SUVmean values measured in the carotid arteries decreased from 0.97 without a coil to 0.96 (Siemens) and 0.88 (Machnet). Carotid surface coils do affect attenuation correction in both PET/MR and PET/CT imaging. Furthermore, SUVs differed significantly between PET/MR and PET/CT.

Brain PET and functional MRI: why simultaneously using hybrid PET/MR systems?

Science.gov (United States)

Cecchin, Diego; Palombit, Alessandro; Castellaro, Marco; Silvestri, Erica; Bui, Franco; Barthel, Henryk; Sabri, Osama; Corbetta, Maurizio; Bertoldo, Alessandra

2017-12-01

In the last 20 years growing attention has been devoted to multimodal imaging. The recent literature is rich of clinical and research studies that have been performed using different imaging modalities on both separate and integrated positron emission tomography (PET) and magnetic resonance (MR) scanners. However, today, hybrid PET/MR systems measure signals related to brain structure, metabolism, neurochemistry, perfusion, and neuronal activity simultaneously, i.e. in the same physiological conditions. A frequently raised question at meeting and symposia is: "Do we really need a hybrid PET/MR system? Are there any advantages over acquiring sequential and separate PET and MR scans?" The present paper is an attempt to answer these questions specifically in relation to PET combined with functional magnetic resonance imaging (fMRI) and arterial spin labeling. We searched (last update: June 2017) the databases PubMed, PMC, Google Scholar and Medline. We also included additional studies if they were cited in the selected articles. No language restriction was applied to the search, but the reviewed articles were all in English. Among all the retrieved articles, we selected only those performed using a hybrid PET/MR system. We found a total of 17 papers that were selected and discussed in three main groups according to the main radiopharmaceutical used: 18F-fluorodeoxyglucose (18F-FDG) (N.=8), 15O-water (15O-H2O) (N.=3) and neuroreceptors (N.=6). Concerning studies using 18F-FDG, simultaneous PET/fMRI revealed that global aspects of functional organization (e.g. graph properties of functional connections) are partially associated with energy consumption. There are remarkable spatial and functional similarities across modalities, but also discrepant findings. More work is needed on this point. There are only a handful of papers comparing blood flow measurements with PET 15O-H2O and MR arterial spin label (ASL) measures, and they show significant regional CBF differences

Evaluation of the PET component of simultaneous [18F]choline PET/MRI in prostate cancer: comparison with [18F]choline PET/CT

International Nuclear Information System (INIS)

Wetter, Axel; Lipponer, Christine; Nensa, Felix; Altenbernd, Jens-Christian; Schlosser, Thomas; Lauenstein, Thomas; Heusch, Philipp; Ruebben, Herbert; Bockisch, Andreas; Poeppel, Thorsten; Nagarajah, James

2014-01-01

The aim of this study was to evaluate the positron emission tomography (PET) component of [ 18 F]choline PET/MRI and compare it with the PET component of [ 18 F]choline PET/CT in patients with histologically proven prostate cancer and suspected recurrent prostate cancer. Thirty-six patients were examined with simultaneous [ 18 F]choline PET/MRI following combined [ 18 F]choline PET/CT. Fifty-eight PET-positive lesions in PET/CT and PET/MRI were evaluated by measuring the maximum and mean standardized uptake values (SUV max and SUV mean ) using volume of interest (VOI) analysis. A scoring system was applied to determine the quality of the PET images of both PET/CT and PET/MRI. Agreement between PET/CT and PET/MRI regarding SUV max and SUV mean was tested using Pearson's product-moment correlation and Bland-Altman analysis. All PET-positive lesions that were visible on PET/CT were also detectable on PET/MRI. The quality of the PET images was comparable in both groups. Median SUV max and SUV mean of all lesions were significantly lower in PET/MRI than in PET/CT (5.2 vs 6.1, p max of PET/CT and PET/MRI (R = 0.86, p mean of PET/CT and PET/MRI (R = 0.81, p max of PET/CT vs PET/MRI and -1.12 to +2.23 between SUV mean of PET/CT vs PET/MRI. PET image quality of PET/MRI was comparable to that of PET/CT. A highly significant correlation between SUV max and SUV mean was found. Both SUV max and SUV mean were significantly lower in [ 18 F]choline PET/MRI than in [ 18 F]choline PET/CT. Differences of SUV max and SUV mean might be caused by different techniques of attenuation correction. Furthermore, differences in biodistribution and biokinetics of [ 18 F]choline between the subsequent examinations and in the respective organ systems have to be taken into account. (orig.)

[Principles of PET].

Science.gov (United States)

Beuthien-Baumann, B

2018-05-01

Positron emission tomography (PET) is a procedure in nuclear medicine, which is applied predominantly in oncological diagnostics. In the form of modern hybrid machines, such as PET computed tomography (PET/CT) and PET magnetic resonance imaging (PET/MRI) it has found wide acceptance and availability. The PET procedure is more than just another imaging technique, but a functional method with the capability for quantification in addition to the distribution pattern of the radiopharmaceutical, the results of which are used for therapeutic decisions. A profound knowledge of the principles of PET including the correct indications, patient preparation, and possible artifacts is mandatory for the correct interpretation of PET results.

Evaluation of Dixon Sequence on Hybrid PET/MR Compared with Contrast-Enhanced PET/CT for PET-Positive Lesions

International Nuclear Information System (INIS)

Jeong, Ju Hye; Cho, Ihn Ho; Kong, Eun Jung; Chun, Kyung Ah

2014-01-01

Hybrid positron emission tomography and magnetic resonance (PET/MR) imaging performs a two-point Dixon MR sequence for attenuation correction. However, MR data in hybrid PET/MR should provide anatomic and morphologic information as well as an attenuation map. We evaluated the Dixon sequence of hybrid PET/MR for anatomic correlation of PET-positive lesions compared with contrast-enhanced PET/computed tomography (CT) in patients with oncologic diseases. Twelve patients underwent a single injection, dual imaging protocol. PET/CT was performed with an intravenous contrast agent (85±13 min after 18 F-FDG injection of 403± 45 MBq) and then (125±19 min after injection) PET/MR was performed. Attenuation correction and anatomic allocation of PET were performed using contrast-enhanced CT for PET/CT and Dixon MR sequence for hybrid PET/MR. The Dixon MR sequence and contrast-enhanced CT were compared for anatomic correlation of PET-positive lesions (scoring scale ranging from 0 to 3 for visual ratings). Additionally, standardized uptake values (SUVs) for the detected lesions were assessed for quantitative comparison. Both hybrid PET/MR and contrast-enhanced PET/CT identified 55 lesions with increased FDG uptake in ten patients. In total, 28 lymph nodes, 11 bone lesions, 3 dermal nodules, 3 pleural thickening lesions, 2 thyroid nodules, 1 pancreas, 1 liver, 1 ovary, 1 uterus, 1 breast, 1 soft tissue and 2 lung lesions were present. The best performance was observed for anatomic correlation of PET findings by the contrast-enhanced CT scans (contrast-enhanced CT, 2.64± 0.70; in-phase, 1.29±1.01; opposed-phase, 1.29±1.15; water-weighted, 1.71±1.07; fat weighted, 0.56±1.03). A significant difference was observed between the scores obtained from the contrast-enhanced CT and all four coregistered Dixon MR images. Quantitative evaluation revealed a high correlation between the SUVs measured with hybrid PET/MR (SUVmean, 2.63±1.62; SUVmax, 4.30±2.88) and contrast-enhanced PET

Evaluation of Dixon Sequence on Hybrid PET/MR Compared with Contrast-Enhanced PET/CT for PET-Positive Lesions

Energy Technology Data Exchange (ETDEWEB)

Jeong, Ju Hye; Cho, Ihn Ho; Kong, Eun Jung; Chun, Kyung Ah [Yeungnam Univ. Hospital, Daegu (Korea, Republic of)

2014-03-15

Hybrid positron emission tomography and magnetic resonance (PET/MR) imaging performs a two-point Dixon MR sequence for attenuation correction. However, MR data in hybrid PET/MR should provide anatomic and morphologic information as well as an attenuation map. We evaluated the Dixon sequence of hybrid PET/MR for anatomic correlation of PET-positive lesions compared with contrast-enhanced PET/computed tomography (CT) in patients with oncologic diseases. Twelve patients underwent a single injection, dual imaging protocol. PET/CT was performed with an intravenous contrast agent (85±13 min after {sup 18}F-FDG injection of 403± 45 MBq) and then (125±19 min after injection) PET/MR was performed. Attenuation correction and anatomic allocation of PET were performed using contrast-enhanced CT for PET/CT and Dixon MR sequence for hybrid PET/MR. The Dixon MR sequence and contrast-enhanced CT were compared for anatomic correlation of PET-positive lesions (scoring scale ranging from 0 to 3 for visual ratings). Additionally, standardized uptake values (SUVs) for the detected lesions were assessed for quantitative comparison. Both hybrid PET/MR and contrast-enhanced PET/CT identified 55 lesions with increased FDG uptake in ten patients. In total, 28 lymph nodes, 11 bone lesions, 3 dermal nodules, 3 pleural thickening lesions, 2 thyroid nodules, 1 pancreas, 1 liver, 1 ovary, 1 uterus, 1 breast, 1 soft tissue and 2 lung lesions were present. The best performance was observed for anatomic correlation of PET findings by the contrast-enhanced CT scans (contrast-enhanced CT, 2.64± 0.70; in-phase, 1.29±1.01; opposed-phase, 1.29±1.15; water-weighted, 1.71±1.07; fat weighted, 0.56±1.03). A significant difference was observed between the scores obtained from the contrast-enhanced CT and all four coregistered Dixon MR images. Quantitative evaluation revealed a high correlation between the SUVs measured with hybrid PET/MR (SUVmean, 2.63±1.62; SUVmax, 4.30±2.88) and contrast

Les mesures de métrologie pour le CLIC

CERN Document Server

Cherif, A

2008-01-01

Le projet CLIC est en tout point un défi technique majeur ; c?est le cas également pour la mesure dimensionnelle. Quels sont les équipements et les méthodes qui permettent de caractériser les pièces avec une incertitude de mesure aussi réduite que possible, vu les tolérances micrométriques imposées ? Afin de répondre à cette question, une veille technologique a été maintenue sur une longue période. Les acteurs relevants ont été contactés pour bénéficier d?une ouverture sur les dernières avancées dans le domaine. Différentes techniques ont été étudiées et comparées telles que la digitalisation, la tomographie X, la mesure tridimensionnelle. L'assemblage de haute précision des composants est aussi primordial. Sa mise en ?uvre sous un microscope optique ou à l'aide d'une machine tridimensionnelle est en cours d?étude. L'exposé traitera aussi de la mesure de rugosité, un domaine où nous disposons de moyens adaptés aux exigences spécifiques du projet.

Value of a dixon-based MR/PET attenuation correction sequence for the localization and evaluation of PET-positive lesions

International Nuclear Information System (INIS)

Eiber, Matthias; Holzapfel, Konstantin; Rummeny, Ernst J.; Martinez-Moeller, Axel; Souvatzoglou, Michael; Ziegler, Sibylle; Schwaiger, Markus; Nekolla, Stephan G.; Beer, Ambros J.; Pickhard, Anja; Loeffelbein, Dennys; Santi, Ivan

2011-01-01

In this study, the potential contribution of Dixon-based MR imaging with a rapid low-resolution breath-hold sequence, which is a technique used for MR-based attenuation correction (AC) for MR/positron emission tomography (PET), was evaluated for anatomical correlation of PET-positive lesions on a 3T clinical scanner compared to low-dose CT. This technique is also used in a recently installed fully integrated whole-body MR/PET system. Thirty-five patients routinely scheduled for oncological staging underwent 18 F-fluorodeoxyglucose (FDG) PET/CT and a 2-point Dixon 3-D volumetric interpolated breath-hold examination (VIBE) T1-weighted MR sequence on the same day. Two PET data sets reconstructed using attenuation maps from low-dose CT (PET AC C T ) or simulated MR-based segmentation (PET AC M R ) were evaluated for focal PET-positive lesions. The certainty for the correlation with anatomical structures was judged in the low-dose CT and Dixon-based MRI on a 4-point scale (0-3). In addition, the standardized uptake values (SUVs) for PET AC C T and PET AC M R were compared. Statistically, no significant difference could be found concerning anatomical localization for all 81 PET-positive lesions in low-dose CT compared to Dixon-based MR (mean 2.51 ± 0.85 and 2.37 ± 0.87, respectively; p = 0.1909). CT tended to be superior for small lymph nodes, bone metastases and pulmonary nodules, while Dixon-based MR proved advantageous for soft tissue pathologies like head/neck tumours and liver metastases. For the PET AC C T - and PET AC M R -based SUVs (mean 6.36 ± 4.47 and 6.31 ± 4.52, respectively) a nearly complete concordance with a highly significant correlation was found (r = 0.9975, p < 0.0001). Dixon-based MR imaging for MR AC allows for anatomical allocation of PET-positive lesions similar to low-dose CT in conventional PET/CT. Thus, this approach appears to be useful for future MR/PET for body regions not fully covered by diagnostic MRI due to potential time

PetIGA-MF: a multi-field high-performance toolbox for structure-preserving B-splines spaces

KAUST Repository

Sarmiento, Adel; Cô rtes, A.M.A.; Garcia, D.A.; Dalcin, Lisandro; Collier, N.; Calo, V.M.

2016-01-01

We describe a high-performance solution framework for isogeometric discrete differential forms based on B-splines: PetIGA-MF. Built on top of PetIGA, an open-source library we have built and developed over the last decade, PetIGA-MF is a general

FDG whole-body PET/MRI in oncology: A systematic review

Energy Technology Data Exchange (ETDEWEB)

Kwon, Hyun Woo [Dept. of Nuclear Medicine, Soonchunhyang University Hospital, Cheonan (Korea, Republic of); Becker, Ann-Katharina [Rheinisch Westfalische Technische Hochschule Aachen University, Aachen (Germany); Goo, Jin Mo; Cheon, Gi Jeong [Seoul National University, College of Medicine,Seoul (Korea, Republic of)

2017-03-15

The recent advance in hybrid imaging techniques enables offering simultaneous positron emission tomography (PET)/magnetic resonance imaging (MRI) in various clinical fields. 18F-fluorodeoxyglucose (FDG) PET has been widely used for diagnosis and evaluation of oncologic patients. The growing evidence from research and clinical experiences demonstrated that PET/MRI with FDG can provide comparable or superior diagnostic performance more than conventional radiological imaging such as computed tomography (CT), MRI or PET/CT in various cancers. Combined analysis using structural information and functional/molecular information of tumors can draw additional diagnostic information based on PET/MRI. Further studies including determination of the diagnostic efficacy, optimizing the examination protocol, and analysis of the hybrid imaging results is necessary for extending the FDG PET/MRI application in clinical oncology.

Usefulness of PET in non-lesional temporal lobe epilepsy

International Nuclear Information System (INIS)

Bertuluchi, M.; Arganaraz, R.; Buznick, J.; Pomata, H.

2011-01-01

Objective. To evaluate the usefulness of PET in patients with refractory non-lesional temporal lobe epilepsy. Material and methods. We present three patients with features of temporal lobe epilepsy refractory to medication, where high definition MRI was normal. Results. These patients had PET hypometabolism in the temporal areas related to clinical and neurophysiological findings. Two of these patients were implanted with subdural grids to confirm the diagnosis and the third was operated directly based on the findings of PET. Encourage the presentation of the importance in recent years is acquiring the PET. Conclusion. In those patients in clinical neurophysiology and epilepsy with suspected temporal lobe, but in the MRI images show no structural lesions, PET can play an important role defining the diagnosis. (authors)

Lung PET scan

Science.gov (United States)

... Chest PET scan; Lung positron emission tomography; PET - chest; PET - lung; PET - tumor imaging; ... Grainger & Allison's Diagnostic Radiology: A Textbook of Medical Imaging . 6th ed. Philadelphia, ...

Development and Validation of a Multipoint Based Laser Alignment System for CLIC

CERN Document Server

Stern, G; Lackner, F; Mainaud-Durand, H; Piedigrossi, D; Sandomierski, J; Sosin, M; Geiger, A; Guillaume, S

2013-01-01

Alignment is one of the major challenges within CLIC study, since all accelerator components have to be aligned with accuracy up to 10 μm over sliding windows of 200 m. So far, the straight line reference concept has been based on stretched wires coupled with Wire Positioning Sensors. This concept should be validated through inter-comparison with an alternative solution. This paper proposes an alternative concept where laser beam acts as straight line reference and optical shutters coupled with cameras visualise the beam. The principle was first validated by a series of tests using low-cost components. Yet, in order to further decrease measurement uncertainty in this validation step, a high-precision automatised micrometric table and reference targets have been added to the setup. The paper presents the results obtained with this new equipment, in terms of measurement precision. In addition, the paper gives an overview of first tests done at long distance (up to 53 m), having emphasis on beam divergence

High Frequency Effects of Impedances and Coatings in the CLIC Damping Rings

CERN Document Server

Koukovini Platia, Eirini; Rumolo, G

The Compact Linear Collider (CLIC) is a 3 TeV eÅe¡ machine, currently under design at CERN, that targets to explore the terascale particle physics regime. The experiment requires a high luminosity of 2£1034 cm2 s¡1, which can be achieved with ultra low emittances delivered from the Damping Rings (DRs) complex. The high bunch brightness of the DRs gives rise to several collective effects that can limit the machine performance. Impedance studies during the design stage of the DR are of great importance to ensure safe operation under nominal parameters. As a first step, the transverse impedance model of the DRis built, accounting for the wholemachine. Beam dynamics simulations are performedwith HEADTAIL to investigate the effect on beam dynamics. For the correct impedancemodeling of the machine elements, knowledge of the material properties is essential up to hundreds of GHz, where the bunch spectrum extends. Specifically, Non Evaporable Getter (NEG) is a commonly used coating for good vacuumbut its properti...

Regional quantitative analysis of cortical surface maps of FDG PET images

CERN Document Server

Protas, H D; Hayashi, K M; Chin Lung, Yu; Bergsneider, M; Sung Cheng, Huang

2006-01-01

Cortical surface maps are advantageous for visualizing the 3D profile of cortical gray matter development and atrophy, and for integrating structural and functional images. In addition, cortical surface maps for PET data, when analyzed in conjunction with structural MRI data allow us to investigate, and correct for, partial volume effects. Here we compared quantitative regional PET values based on a 3D cortical surface modeling approach with values obtained directly from the 3D FDG PET images in various atlas-defined regions of interest (ROIs; temporal, parietal, frontal, and occipital lobes). FDG PET and 3D MR (SPGR) images were obtained and aligned to ICBM space for 15 normal subjects. Each image was further elastically warped in 2D parameter space of the cortical surface, to align major cortical sulci. For each point within a 15 mm distance of the cortex, the value of the PET intensity was averaged to give a cortical surface map of FDG uptake. The average PET values on the cortical surface map were calcula...

Simultaneous evaluation of brain tumour metabolism, structure and blood volume using [{sup 18}F]-fluoroethyltyrosine (FET) PET/MRI: feasibility, agreement and initial experience

Energy Technology Data Exchange (ETDEWEB)

Henriksen, Otto M.; Hansen, Adam E.; Law, Ian [Copenhagen University Hospital Rigshospitalet Blegdamsvej, Department of Clinical Physiology Nuclear Medicine and PET, Copenhagen (Denmark); Larsen, Vibeke A. [Copenhagen University Hospital Rigshospitalet Blegdamsvej, Department of Radiology, Copenhagen (Denmark); Muhic, Aida; Poulsen, Hans S. [Copenhagen University Hospital Rigshospitalet Blegdamsvej, Department of Oncology, Copenhagen (Denmark); Larsson, Henrik B.W. [Copenhagen University Hospital Rigshospitalet Glostrup, Functional Imaging Unit, Department of Clinical Physiology Nuclear Medicine and PET, Glostrup (Denmark)

2016-01-15

Both [{sup 18}F]-fluoroethyltyrosine (FET) PET and blood volume (BV) MRI supplement routine T1-weighted contrast-enhanced MRI in gliomas, but whether the two modalities provide identical or complementary information is unresolved. The aims of the study were to investigate the feasibility of simultaneous structural MRI, BV MRI and FET PET of gliomas using an integrated PET/MRI scanner and to assess the spatial and quantitative agreement in tumour imaging between BV MRI and FET PET. A total of 32 glioma patients underwent a 20-min static simultaneous PET/MRI acquisition on a Siemens mMR system 20 min after injection of 200 MBq FET. The MRI protocol included standard structural MRI and dynamic susceptibility contrast (DSC) imaging for BV measurements. Maximal relative tumour FET uptake (TBR{sub max}) and BV (rBV{sub max}), and Dice coefficients were calculated to assess the quantitative and spatial congruence in the tumour volumes determined by FET PET, BV MRI and contrast-enhanced MRI. FET volume and TBR{sub max} were higher in BV-positive than in BV-negative scans, and both VOL{sub BV} and rBV{sub max} were higher in FET-positive than in FET-negative scans. TBR{sub max} and rBV{sub max} were positively correlated (R{sup 2} = 0.59, p < 0.001). FET and BV positivity were in agreement in only 26 of the 32 patients and in 42 of 63 lesions, and spatial congruence in the tumour volumes as assessed by the Dice coefficients was generally poor with median Dice coefficients exceeding 0.1 in less than half the patients positive on at least one modality for any pair of modalities. In 56 % of the patients susceptibility artefacts in DSC BV maps overlapped the tumour on MRI. The study demonstrated that although tumour volumes determined by BV MRI and FET PET were quantitatively correlated, their spatial congruence in a mixed population of treated glioma patients was generally poor, and the modalities did not provide the same information in this population of patients. Combined

Simultaneous PET/MRI with 13C magnetic resonance spectroscopic imaging (hyperPET): phantom-based evaluation of PET quantification

DEFF Research Database (Denmark)

Hansen, Adam E.; Andersen, Flemming L.; Henriksen, Sarah T.

2016-01-01

Background: Integrated PET/MRI with hyperpolarized 13C magnetic resonance spectroscopic imaging (13C-MRSI) offers simultaneous, dual-modality metabolic imaging. A prerequisite for the use of simultaneous imaging is the absence of interference between the two modalities. This has been documented...... for a clinical whole-body system using simultaneous 1 H-MRI and PET but never for 13C-MRSI and PET. Here, the feasibility of simultaneous PET and 13C-MRSI as well as hyperpolarized 13C-MRSI in an integrated whole-body PET/MRI hybrid scanner is evaluated using phantom experiments. Methods: Combined PET and 13C......-MRSI phantoms including a NEMA [18F]-FDG phantom, 13C-acetate and 13C-urea sources, and hyperpolarized 13C-pyruvate were imaged repeatedly with PET and/or 13C-MRSI. Measurements evaluated for interference effects included PET activity values in the largest sphere and a background region; total number of PET...

Positron Emission Tomography (PET)

International Nuclear Information System (INIS)

Welch, M.J.

1990-01-01

Positron emission tomography (PET) assesses biochemical processes in the living subject, producing images of function rather than form. Using PET, physicians are able to obtain not the anatomical information provided by other medical imaging techniques, but pictures of physiological activity. In metaphoric terms, traditional imaging methods supply a map of the body's roadways, its, anatomy; PET shows the traffic along those paths, its biochemistry. This document discusses the principles of PET, the radiopharmaceuticals in PET, PET research, clinical applications of PET, the cost of PET, training of individuals for PET, the role of the United States Department of Energy in PET, and the futures of PET. 22 figs

Positron Emission Tomography (PET)

Science.gov (United States)

Welch, M. J.

1990-01-01

Positron emission tomography (PET) assesses biochemical processes in the living subject, producing images of function rather than form. Using PET, physicians are able to obtain not the anatomical information provided by other medical imaging techniques, but pictures of physiological activity. In metaphoric terms, traditional imaging methods supply a map of the body's roadways, its, anatomy; PET shows the traffic along those paths, its biochemistry. This document discusses the principles of PET, the radiopharmaceuticals in PET, PET research, clinical applications of PET, the cost of PET, training of individuals for PET, the role of the United States Department of Energy in PET, and the futures of PET.

Positron Emission Tomography (PET)

Energy Technology Data Exchange (ETDEWEB)

Welch, M.J.

1990-01-01

Positron emission tomography (PET) assesses biochemical processes in the living subject, producing images of function rather than form. Using PET, physicians are able to obtain not the anatomical information provided by other medical imaging techniques, but pictures of physiological activity. In metaphoric terms, traditional imaging methods supply a map of the body's roadways, its, anatomy; PET shows the traffic along those paths, its biochemistry. This document discusses the principles of PET, the radiopharmaceuticals in PET, PET research, clinical applications of PET, the cost of PET, training of individuals for PET, the role of the United States Department of Energy in PET, and the futures of PET. 22 figs.

Indeterminate findings on oncologic PET/CT: What difference dose PET/MRI make?

Energy Technology Data Exchange (ETDEWEB)

Fraum, Tyler J.; Fowler, Kathryn J.; McConathy, Jonathan; Dehdashti, Farokh [Mallinckrodt Institute of Radiology, Washington University School of Medicine, Saint Louis (United States)

2016-12-15

Positron emission tomography/computed tomography (PET/CT) with 2-deoxy-2-[{sup 18}F]fluoro-D-glucose (FDG) has become the standard of care for the initial staging and subsequent treatment response assessment of many different malignancies. Despite this success, PET/CT is often supplemented by MRI to improve assessment of local tumor invasion and to facilitate detection of lesions in organs with high background FDG uptake. Consequently, PET/MRI has the potential to expand the clinical value of PET examinations by increasing reader certainty and reducing the need for subsequent imaging. This study evaluates the ability of FDG-PET/MRI to clarify findings initially deemed indeterminate on clinical FDG-PET/CT studies. A total of 190 oncology patients underwent whole-body PET/CT, immediately followed by PET/MRI utilizing the same FDG administration. Each PET/CT was interpreted by our institution's nuclear medicine service as a standard-of-care clinical examination. Review of these PET/CT reports identified 31 patients (16 %) with indeterminate findings. Two readers evaluated all 31 PET/CT studies, followed by the corresponding PET/MRI studies. A consensus was reached for each case, and changes in interpretation directly resulting from PET/MRI review were recorded. Interpretations were then correlated with follow-up imaging, pathology results, and other diagnostic studies. In 18 of 31 cases with indeterminate findings on PET/CT, PET/MRI resulted in a more definitive interpretation by facilitating the differentiation of infection/inflammation from malignancy (15/18), the accurate localization of FDG-avid lesions (2/18), and the characterization of incidental non-FDG-avid solid organ lesions (1/18). Explanations for improved reader certainty with PET/MRI included the superior soft tissue contrast of MRI and the ability to assess cellular density with diffusion-weighted imaging. The majority (12/18) of such cases had an appropriate standard of reference; in all 12 cases

Indeterminate findings on oncologic PET/CT: What difference dose PET/MRI make?

International Nuclear Information System (INIS)

Fraum, Tyler J.; Fowler, Kathryn J.; McConathy, Jonathan; Dehdashti, Farokh

2016-01-01

Positron emission tomography/computed tomography (PET/CT) with 2-deoxy-2-["1"8F]fluoro-D-glucose (FDG) has become the standard of care for the initial staging and subsequent treatment response assessment of many different malignancies. Despite this success, PET/CT is often supplemented by MRI to improve assessment of local tumor invasion and to facilitate detection of lesions in organs with high background FDG uptake. Consequently, PET/MRI has the potential to expand the clinical value of PET examinations by increasing reader certainty and reducing the need for subsequent imaging. This study evaluates the ability of FDG-PET/MRI to clarify findings initially deemed indeterminate on clinical FDG-PET/CT studies. A total of 190 oncology patients underwent whole-body PET/CT, immediately followed by PET/MRI utilizing the same FDG administration. Each PET/CT was interpreted by our institution's nuclear medicine service as a standard-of-care clinical examination. Review of these PET/CT reports identified 31 patients (16 %) with indeterminate findings. Two readers evaluated all 31 PET/CT studies, followed by the corresponding PET/MRI studies. A consensus was reached for each case, and changes in interpretation directly resulting from PET/MRI review were recorded. Interpretations were then correlated with follow-up imaging, pathology results, and other diagnostic studies. In 18 of 31 cases with indeterminate findings on PET/CT, PET/MRI resulted in a more definitive interpretation by facilitating the differentiation of infection/inflammation from malignancy (15/18), the accurate localization of FDG-avid lesions (2/18), and the characterization of incidental non-FDG-avid solid organ lesions (1/18). Explanations for improved reader certainty with PET/MRI included the superior soft tissue contrast of MRI and the ability to assess cellular density with diffusion-weighted imaging. The majority (12/18) of such cases had an appropriate standard of reference; in all 12 cases, the

PET and PET/CT in tumour of undetermined origin; PET y PET/CT en tumor de origen indeterminado

Energy Technology Data Exchange (ETDEWEB)

Garcia O, J R [Nuclear Medicine and Molecular Imaging, PET/CT, Centro Medico ABC, Mexico D.F. (Mexico)

2007-07-01

In this presentation the following conclusions were obtained regarding the use of PET and PET/CT in patient with cancer of unknown primary: 1. Detection of the primary one in 1/3 at 1/2 of patient. 2. It detects metastases in other places in 50%. 3. It changes the initial therapy planned in 1/3 at 1/2 of patient. 4. Useful in initial phases of protocol study to limit the other procedures. After standard evaluation. Before advanced protocol. 5. PET/CT study increases the % of primary detection, although in a non significant way vs. PET. 6. They are required more studies to value their utility to a more objective manner. (Author)

Mechanical and thermal properties of commercial multilayer PET/PP film irradiated with electron-beam

International Nuclear Information System (INIS)

Ortiz, Angel V.; Nogueira, Beatriz R.; Oliveira, Vitor M.; Moura, Esperidiana A.B.

2009-01-01

The effects of electron-beam irradiation on mechanical and thermal properties, for one commercial flexible food packaging multilayer structure, were studied. The laminated poly(ethylene terephthalate) (PET)/ polypropylene (PP) structure was irradiated up to 60 kGy, using a 1.5 MeV electron beam accelerator, at room temperature in the presence of air. Mechanical properties showed significant changes (p < 0.05). In addition, the DSC analysis, after treatment, showed that the fusion enthalpy and crystallinity of the PET/PP structure components presented significant changes (p < 0.05) with the electron-beam radiation doses applied. It was observed an increase in PP crystallinity while the PET crystallinity decreases. Such decrease in PET crystallinity indicates the predominance of a cross-linking process on the irradiated PET layer; responsible for the increase in some mechanical properties of the studied film. (author)

Simultaneous PET/MRI with (13)C magnetic resonance spectroscopic imaging (hyperPET): phantom-based evaluation of PET quantification.

Science.gov (United States)

Hansen, Adam E; Andersen, Flemming L; Henriksen, Sarah T; Vignaud, Alexandre; Ardenkjaer-Larsen, Jan H; Højgaard, Liselotte; Kjaer, Andreas; Klausen, Thomas L

2016-12-01

Integrated PET/MRI with hyperpolarized (13)C magnetic resonance spectroscopic imaging ((13)C-MRSI) offers simultaneous, dual-modality metabolic imaging. A prerequisite for the use of simultaneous imaging is the absence of interference between the two modalities. This has been documented for a clinical whole-body system using simultaneous (1)H-MRI and PET but never for (13)C-MRSI and PET. Here, the feasibility of simultaneous PET and (13)C-MRSI as well as hyperpolarized (13)C-MRSI in an integrated whole-body PET/MRI hybrid scanner is evaluated using phantom experiments. Combined PET and (13)C-MRSI phantoms including a NEMA [(18)F]-FDG phantom, (13)C-acetate and (13)C-urea sources, and hyperpolarized (13)C-pyruvate were imaged repeatedly with PET and/or (13)C-MRSI. Measurements evaluated for interference effects included PET activity values in the largest sphere and a background region; total number of PET trues; and (13)C-MRSI signal-to-noise ratio (SNR) for urea and acetate phantoms. Differences between measurement conditions were evaluated using t tests. PET and (13)C-MRSI data acquisition could be performed simultaneously without any discernible artifacts. The average difference in PET activity between acquisitions with and without simultaneous (13)C-MRSI was 0.83 (largest sphere) and -0.76 % (background). The average difference in net trues was -0.01 %. The average difference in (13)C-MRSI SNR between acquisitions with and without simultaneous PET ranged from -2.28 to 1.21 % for all phantoms and measurement conditions. No differences were significant. The system was capable of (13)C-MRSI of hyperpolarized (13)C-pyruvate. Simultaneous PET and (13)C-MRSI in an integrated whole-body PET/MRI hybrid scanner is feasible. Phantom experiments showed that possible interference effects introduced by acquiring data from the two modalities simultaneously are small and non-significant. Further experiments can now investigate the benefits of simultaneous PET and

Assessment of PET & ASL metabolism in the hippocampal subfields of MCI and AD using simultaneous PET-MR

Energy Technology Data Exchange (ETDEWEB)

Goubran, Maged; Douglas, David; Chao, Steven; Quon, Andrew; Tripathi, Pragya; Holley, Dawn; Vasanawala, Minal; Zaharchuk, Greg; Zeineh, Michael [Stanford University (United States)

2015-05-18

Alzheimer’s disease (AD) has been reported to show decreased metabolic activity in the hippocampus using FDG PET-MR. Histological data suggests that the hippocampal subfields are selectively affected in AD. Given the simultaneous imaging nature of integrated PET-MR scanners and the multimodal capabilities of PET-MR, our purpose here is to assess FDG activity, as well as ASL perfusion in the subfields of MCI and AD patients. 10 consecutive subjects were recruited for this study 3 MCI, 3 AD patients and 4 age-matched controls. The scanning was performed on a simultaneous 3T PET/MR scanner. To delineate the hippocampal subfields, automatic segmentation of hippocampal subfields (ASHS) was employed. Static FDG-PET series were reconstructed for analysis at 45-75 min for all subjects. All imaging sequences were automatically registered to the oblique coronal T2-weighted images (segmentation space). PET standardized uptake values (SUV) in the hippocampal subfields were normalized by the pons. FDG PET metabolism was reduced significantly in AD, as well as MCI patients as compared to controls, with the highest effect demonstrated in the CA3/DG and CA1/2 (p = 0.047, subfields. Patients (MCI and AD combined) had decreased metabolism as compared to controls in CA1/2 and significantly smaller volumes the Subiculum. When assessing CBF across groups, a significant decrease in CBF was found in the Subiculum. Our preliminary results demonstrate that PET-MRI may potentially be a sensitive biomarker and tool for early diagnosis of AD. They also confirm the importance of assessing metabolic and structural changes of neurodegenerative diseases at the subfield level.

4D PET iterative deconvolution with spatiotemporal regularization for quantitative dynamic PET imaging.

Science.gov (United States)

Reilhac, Anthonin; Charil, Arnaud; Wimberley, Catriona; Angelis, Georgios; Hamze, Hasar; Callaghan, Paul; Garcia, Marie-Paule; Boisson, Frederic; Ryder, Will; Meikle, Steven R; Gregoire, Marie-Claude

2015-09-01

Quantitative measurements in dynamic PET imaging are usually limited by the poor counting statistics particularly in short dynamic frames and by the low spatial resolution of the detection system, resulting in partial volume effects (PVEs). In this work, we present a fast and easy to implement method for the restoration of dynamic PET images that have suffered from both PVE and noise degradation. It is based on a weighted least squares iterative deconvolution approach of the dynamic PET image with spatial and temporal regularization. Using simulated dynamic [(11)C] Raclopride PET data with controlled biological variations in the striata between scans, we showed that the restoration method provides images which exhibit less noise and better contrast between emitting structures than the original images. In addition, the method is able to recover the true time activity curve in the striata region with an error below 3% while it was underestimated by more than 20% without correction. As a result, the method improves the accuracy and reduces the variability of the kinetic parameter estimates calculated from the corrected images. More importantly it increases the accuracy (from less than 66% to more than 95%) of measured biological variations as well as their statistical detectivity. Crown Copyright © 2015. Published by Elsevier Inc. All rights reserved.

Study on the application of PET-CT in gynecology tumors

International Nuclear Information System (INIS)

Wen Lilian

2012-01-01

Gynecology tumors seriously threatened the health of female. With the development of imageology, PET, a functionality examination method, has been widely used in the early diagnosis and monitoring of curative effect in gynecology tumors. PET-CT has the good future in its development because it combined with the advantage of functional and structural imaging. The characters and application of PET-CT in gynecology tumors were reviewed in this paper. (author)

Pet Allergy Quiz

Science.gov (United States)

... Treatments ▸ Allergies ▸ Pet Allergy ▸ Pet Allergy Quiz Share | Pet Allergy Quiz More than half of U.S. households ... cat family. Yet, millions of people suffer from pet allergies. Take this quiz to test your knowledge ...

Colorectal cancer staging: comparison of whole-body PET/CT and PET/MR.

Science.gov (United States)

Catalano, Onofrio A; Coutinho, Artur M; Sahani, Dushyant V; Vangel, Mark G; Gee, Michael S; Hahn, Peter F; Witzel, Thomas; Soricelli, Andrea; Salvatore, Marco; Catana, Ciprian; Mahmood, Umar; Rosen, Bruce R; Gervais, Debra

2017-04-01

Correct staging is imperative for colorectal cancer (CRC) since it influences both prognosis and management. Several imaging methods are used for this purpose, with variable performance. Positron emission tomography-magnetic resonance (PET/MR) is an innovative imaging technique recently employed for clinical application. The present study was undertaken to compare the staging accuracy of whole-body positron emission tomography-computed tomography (PET/CT) with whole-body PET/MR in patients with both newly diagnosed and treated colorectal cancer. Twenty-six patients, who underwent same day whole-body (WB) PET/CT and WB-PET/MR, were evaluated. PET/CT and PET/MR studies were interpreted by consensus by a radiologist and a nuclear medicine physician. Correlations with prior imaging and follow-up studies were used as the reference standard. Correct staging was compared between methods using McNemar's Chi square test. The two methods were in agreement and correct for 18/26 (69%) patients, and in agreement and incorrect for one patient (3.8%). PET/MR and PET/CT stages for the remaining 7/26 patients (27%) were discordant, with PET/MR staging being correct in all seven cases. PET/MR significantly outperformed PET/CT overall for accurate staging (P = 0.02). PET/MR outperformed PET/CT in CRC staging. PET/MR might allow accurate local and distant staging of CRC patients during both at the time of diagnosis and during follow-up.

Proposal to negotiate extensions to four collaboration agreements for the design of key components of the beam-delivery and linac systems for the Compact Linear Collider (CLIC) for a duration of two years

CERN Document Server

2017-01-01

Proposal to negotiate extensions to four collaboration agreements for the design of key components of the beam-delivery and linac systems for the Compact Linear Collider (CLIC) for a duration of two years

TOF-PET/MR和TOF-PET/CT在体部恶性肿瘤SUVmax值的比较%Comparision of SUVmax of TOF-PET/MR and TOF-PET/CT in body malignant tumor

Institute of Scientific and Technical Information of China (English)

宋天彬; 卢洁; 崔碧霄; 马杰; 杨宏伟; 马蕾; 梁志刚

2017-01-01

目的 探讨时间飞行(TOF)技术PET/CT和PET/MR检查体部恶性病变SUVmax值的一致性.方法 回顾性分析接受TOF-PET/CT和TOF-PET/MR检查的体部恶性肿瘤患者20例,分为先PET/CT后PET/MR组和先PET/MR后PET/CT组,每组10例.采用Bland-Altma图评价两次检查病灶SUVmax值的一致性,采用多因素方差分析评价扫描顺序和机器类型对病灶的SUVmax测量值的影响.结果 TOF-PET/CT与TOF-PET/MR检查病灶的SUVmax值有较好的一致性[先PET/CT后PET/MR组:均值差为3.06,95％CI(-7.5,13.6),先PET/MR后PET/CT组:均值差3.0,95％CI(-2.4,8.3)].扫描顺序对于恶性病灶的SUVmax有影响(F=46.00,P＜0.001),而机器类型对恶性病灶的SUVmax值无影响(F=0.005,P=0.95).结论 TOF-PET/MR和TOF-PET/CT在体部恶性病变SUVmax值测量方面具有相当的诊断价值,且延迟显像SUVmax的增加与采集时间有关,而与检查机器类型无关.%Objective To explore the consistency of time-of-flight (TOF) technology of PET/MRI and PET/CT for max standardized uptake value (SUVmax) of body malignant tumors.Methods A retrospective analysis of TOF-PET/CT and TOF-PET/MR imaging data about twenty patients with body malignant tumors was performed.Patients were divided into two groups (each n=10),including PET/CT first and sequentially PET/MR group and PET/MR first and sequentially PET/CT group.Bland-Altman figure was used to evaluate consistency of SUVmax of malignant lesions between TOF-PET/CT and TOF-PET/MR.Multi-way ANOVA was used to analysis effect of machine type and exam order on SUVmaxof malignant lesions in TOF-PET/CT and TOF-PET/MR.Results SUVmax of malignant lesions in TOF-PET/CT and TOF-PET/MR had good consistency in two groups (PET/CT first and sequentially PET/MR group:Mean difference was 3.06,95％CI was [-7.5,13.6];PET/MR first and sequentially PET/CT group:Mean difference was 3.0,95％CI was [-2.4,8.3]).SUVmax was not influenced by machine type (F=0.005,P=0.95),but exam order (F=46.00,P＜0

First PET Center in Mexico: the power of molecular imaging

International Nuclear Information System (INIS)

Avila R, M.A.

2001-01-01

Positron Emission Tomography (PET) is a non-invasive diagnostic imaging technique modality. It represents the forefront of medical images and was developed as a quantitative technique for imaging biochemical and physiological processes in the human body. PET is unique because it produces images of the body's basic biochemistry or function. Traditional diagnostic techniques such as x-rays, CT scans or MRI, produce images of the body's anatomy or structure. The premise with these techniques is that the change in anatomy or structure that occurs with disease can be seen. However, biochemical processes are also altered with disease and may occur before there is a change gross anatomy. PET is an imaging technique that is used to visualize some of these processes. The development of PET as we know it today began in 1974 with the development of a single ring detector system by Phelps et al. Today, over 350 PET scanners are in use in the world, mainly in the USA (over 140), Europe (particularly in the Anglo-Saxon countries and France) and Japan. Many of these facilities also have their own cyclotron to produce the positron emitters. In the Southern hemisphere, only Australia, Argentina. and recently Mexico, have a very small number of PET facilities. (Author)

First PET Center in Mexico: the power of molecular imaging

Energy Technology Data Exchange (ETDEWEB)

Avila R, M.A. [Unidad PET, Facultad de Medicina, UNAM (Mexico)

2001-09-01

Positron Emission Tomography (PET) is a non-invasive diagnostic imaging technique modality. It represents the forefront of medical images and was developed as a quantitative technique for imaging biochemical and physiological processes in the human body. PET is unique because it produces images of the body's basic biochemistry or function. Traditional diagnostic techniques such as x-rays, CT scans or MRI, produce images of the body's anatomy or structure. The premise with these techniques is that the change in anatomy or structure that occurs with disease can be seen. However, biochemical processes are also altered with disease and may occur before there is a change gross anatomy. PET is an imaging technique that is used to visualize some of these processes. The development of PET as we know it today began in 1974 with the development of a single ring detector system by Phelps et al. Today, over 350 PET scanners are in use in the world, mainly in the USA (over 140), Europe (particularly in the Anglo-Saxon countries and France) and Japan. Many of these facilities also have their own cyclotron to produce the positron emitters. In the Southern hemisphere, only Australia, Argentina. and recently Mexico, have a very small number of PET facilities. (Author)

Prediction for CP violation via electric dipole moment of τ lepton in γγ→τ{sup +}τ{sup −} process at CLIC

Energy Technology Data Exchange (ETDEWEB)

Atağ, S. [Department of Physics, Faculty of Sciences, Ankara University,06100 Tandogan, Ankara (Turkey); Gürkanlı, E. [Department of Physics, Sinop University,57000 Sinop (Turkey); Department of Physics, Faculty of Sciences, Ankara University,06100 Tandogan, Ankara (Turkey)

2016-06-21

Pair production of tau leptons in two photon collision γγ→τ{sup +}τ{sup −} is studied at CLIC to test CP violating QED couplings of tau leptons. CP violating effects are investigated using tau pair spin correlations which are observed through the hadronic decay of each τ into πν. Competitive bounds with previous works on the electric dipole moment from CP odd terms have been obtained.

Adhesion of nitrile rubber to UV-assisted surface chemical modified PET fabric, part II: Interfacial characterization of MDI grafted PET

Energy Technology Data Exchange (ETDEWEB)

Razavizadeh, Mahmoud; Jamshidi, Masoud, E-mail: mjamshidi@iust.ac.ir

2016-08-30

Highlights: • In this research UV-irradiated PET fabric was chemically modified. • The fabric at first carboxylated under UV irradiation using glutaric anhydride, then it was grafted using isocyanate (i.e. MDI). • The surface of the fabric was characterized before and after each treating satge. • The composite samples were prepared and tested for T-Peel test. The surfaces of the fabrics were surface characterized to understand. - Abstract: Fiber to rubber adhesion is an important subject in rubber industry. It is well known that surface treatment (i.e. physical, mechanical and chemical) is an effective method to improve interfacial bonding of fibers and/or fabrics to rubbers. UV irradiation is an effective method which has been used to increase fabric-rubber interfacial interactions. In this research UV assisted chemical modification of PET fabrics was used to increase PET to nitrile rubber (NBR) adhesion. Nitrile rubber is a perfect selection as fuel and oil resistant rubber. However it has weak bonding to PET fabric. For this purpose PET fabric was carboxylated under UV irradiation and then methylenediphenyl diisocyanate (MDI) was grafted on carboxylated PET. The chemical composition of the fabric before and after surface treatment was investigated by X-ray photoelectron spectroscopy (XPS). The sectional morphology of the experimental PET fibers and the interface between rubber compound and PET fabric was studied using scanning electron microscope (SEM). The morphology and structure of the product were analyzed by an energy dispersive X-ray spectrometer (EDX). FTIR-ATR and H NMR analysis were used to assess surface modifications on the PET irradiated fabrics.

Adhesion of nitrile rubber to UV-assisted surface chemical modified PET fabric, part II: Interfacial characterization of MDI grafted PET

International Nuclear Information System (INIS)

Razavizadeh, Mahmoud; Jamshidi, Masoud

2016-01-01

Highlights: • In this research UV-irradiated PET fabric was chemically modified. • The fabric at first carboxylated under UV irradiation using glutaric anhydride, then it was grafted using isocyanate (i.e. MDI). • The surface of the fabric was characterized before and after each treating satge. • The composite samples were prepared and tested for T-Peel test. The surfaces of the fabrics were surface characterized to understand. - Abstract: Fiber to rubber adhesion is an important subject in rubber industry. It is well known that surface treatment (i.e. physical, mechanical and chemical) is an effective method to improve interfacial bonding of fibers and/or fabrics to rubbers. UV irradiation is an effective method which has been used to increase fabric-rubber interfacial interactions. In this research UV assisted chemical modification of PET fabrics was used to increase PET to nitrile rubber (NBR) adhesion. Nitrile rubber is a perfect selection as fuel and oil resistant rubber. However it has weak bonding to PET fabric. For this purpose PET fabric was carboxylated under UV irradiation and then methylenediphenyl diisocyanate (MDI) was grafted on carboxylated PET. The chemical composition of the fabric before and after surface treatment was investigated by X-ray photoelectron spectroscopy (XPS). The sectional morphology of the experimental PET fibers and the interface between rubber compound and PET fabric was studied using scanning electron microscope (SEM). The morphology and structure of the product were analyzed by an energy dispersive X-ray spectrometer (EDX). FTIR-ATR and H NMR analysis were used to assess surface modifications on the PET irradiated fabrics.

Effect of Attenuation Correction on Regional Quantification Between PET/MR and PET/CT

DEFF Research Database (Denmark)

Teuho, Jarmo; Johansson, Jarkko; Linden, Jani

2016-01-01

UNLABELLED: A spatial bias in brain PET/MR exists compared with PET/CT, because of MR-based attenuation correction. We performed an evaluation among 4 institutions, 3 PET/MR systems, and 4 PET/CT systems using an anthropomorphic brain phantom, hypothesizing that the spatial bias would be minimized....../MR systems, CTAC was applied as the reference method for attenuation correction. RESULTS: With CTAC, visual and quantitative differences between PET/MR and PET/CT systems were minimized. Intersystem variation between institutions was +3.42% to -3.29% in all VOIs for PET/CT and +2.15% to -4.50% in all VOIs...... for PET/MR. PET/MR systems differed by +2.34% to -2.21%, +2.04% to -2.08%, and -1.77% to -5.37% when compared with a PET/CT system at each institution, and these differences were not significant (P ≥ 0.05). CONCLUSION: Visual and quantitative differences between PET/MR and PET/CT systems can be minimized...

History and current status of PET development based on time of flight

International Nuclear Information System (INIS)

Yun Mingkai; Li Ting; Zhang Zhiming; Zhang Yubao; Shan Baoci; Wei Long

2012-01-01

The principle of time of flight (TOF) positron emission tomography (PET) and a brief review of the history of TOF-PET are introduced. The factors influencing the time resolution of a TOF-PET scanner are presented, especially focus on the intrinsic properties of scintillators and front-end electronics. Challenges and achievements of the structure of data organization and image reconstruction are reviewed. Finally, the benefits of TOF-PET on image quality improvement and tumor detection are emphasized. (authors)

Quantitative PET imaging with the 3T MR-BrainPET

International Nuclear Information System (INIS)

Weirich, C.; Scheins, J.; Lohmann, P.; Tellmann, L.; Byars, L.; Michel, C.; Rota Kops, E.; Brenner, D.; Herzog, H.; Shah, N.J.

2013-01-01

The new hybrid imaging technology of MR-PET allows for simultaneous acquisition of versatile MRI contrasts and the quantitative metabolic imaging with PET. In order to achieve the quantification of PET images with minimal residual error the application of several corrections is crucial. In this work we present our results on quantification with the 3T MR BrainPET scanner

PET/MR imaging of bone lesions - implications for PET quantification from imperfect attenuation correction

International Nuclear Information System (INIS)

Samarin, Andrei; Burger, Cyrill; Crook, David W.; Burger, Irene A.; Schmid, Daniel T.; Schulthess, Gustav K. von; Kuhn, Felix P.; Wollenweber, Scott D.

2012-01-01

Accurate attenuation correction (AC) is essential for quantitative analysis of PET tracer distribution. In MR, the lack of cortical bone signal makes bone segmentation difficult and may require implementation of special sequences. The purpose of this study was to evaluate the need for accurate bone segmentation in MR-based AC for whole-body PET/MR imaging. In 22 patients undergoing sequential PET/CT and 3-T MR imaging, modified CT AC maps were produced by replacing pixels with values of >100 HU, representing mostly bone structures, by pixels with a constant value of 36 HU corresponding to soft tissue, thereby simulating current MR-derived AC maps. A total of 141 FDG-positive osseous lesions and 50 soft-tissue lesions adjacent to bones were evaluated. The mean standardized uptake value (SUVmean) was measured in each lesion in PET images reconstructed once using the standard AC maps and once using the modified AC maps. Subsequently, the errors in lesion tracer uptake for the modified PET images were calculated using the standard PET image as a reference. Substitution of bone by soft tissue values in AC maps resulted in an underestimation of tracer uptake in osseous and soft tissue lesions adjacent to bones of 11.2 ± 5.4 % (range 1.5-30.8 %) and 3.2 ± 1.7 % (range 0.2-4 %), respectively. Analysis of the spine and pelvic osseous lesions revealed a substantial dependence of the error on lesion composition. For predominantly sclerotic spine lesions, the mean underestimation was 15.9 ± 3.4 % (range 9.9-23.5 %) and for osteolytic spine lesions, 7.2 ± 1.7 % (range 4.9-9.3 %), respectively. CT data simulating treating bone as soft tissue as is currently done in MR maps for PET AC leads to a substantial underestimation of tracer uptake in bone lesions and depends on lesion composition, the largest error being seen in sclerotic lesions. Therefore, depiction of cortical bone and other calcified areas in MR AC maps is necessary for accurate quantification of tracer uptake

Brain PET scan

Science.gov (United States)

... results on a PET scan. Blood sugar or insulin levels may affect the test results in people with diabetes . PET scans may be done along with a CT scan. This combination scan is called a PET/CT. Alternative Names Brain positron emission tomography; PET scan - brain References Chernecky ...

Clinical PET application

Energy Technology Data Exchange (ETDEWEB)

Lim, Sang Moo; Hong, Song W.; Choi, Chang W.; Yang, Seong Dae [Korea Cancer Center Hospital, Seoul (Korea)

1997-12-01

PET gives various methabolic images, and is very important, new diagnostic modality in clinical oncology. In Korea Cancer Center Hospital, PET is installed as a research tool of long-mid-term atomic research project. For the efficient use of PET for clinical and research projects, income from the patients should be managed to get the raw material, equipment, manpower, and also for the clinical PET research. 1. Support the clinical application of PET in oncology. 2. Budgetary management of income, costs for raw material, equipment, manpower, and the clinical PET research project. In this year, 250 cases of PET images were obtained, which resulted total income of 180,000,000 won. 50,000,000 won was deposited for the 1998 PET clinical research. Second year PET clinical research should be managed under unified project. Increased demand for {sup 18}FDG in and outside KCCH need more than 2 times production of {sup 18}FDG in a day purchase of HPLC pump and {sup 68}Ga pin source which was delayed due to economic crisis, should be done early in 1998. (author). 2 figs., 3 tabs.

PET-Tutorial education program: structure and actions in the cities of São Raimundo Nonato-PI, Juazeiro-BA and Petrolina-PE

Directory of Open Access Journals (Sweden)

Marcelo de Maio Nascimento

2015-12-01

Full Text Available This study presents the PET archeology groups, Biomechanics, Physical Education and Environmental Sanitation, linked to the Federal University of Vale do São Francisco/UNIVASF, which has the multicampi structure. Therefore, PET groups contribute to the process of internalization of higher education in the states of Pernambuco, Bahia and Piauí. His actions prioritize the inseparability of teaching, research and extension, qualifying 48 students fellows. The text highlights the actions of groups during the three-year period, 2011-2013, presenting objectives, methodological procedures and main results obtained to communities that have operated. We conclude that in three years of work, PET teams improved the academic background of a significant group of students of UNIVASF, functioning as a mechanism to align with the academic knowledge to solve social demands within the health and preservation of heritage in the region Northeast of Brazil.

PET and PET/CT in oncology: the key of diagnostic challenge

International Nuclear Information System (INIS)

Mortelmans, L.; Stroobants, S.; Spaepen, K.

2004-01-01

In this presentation authors present use of positron emission tomography (PET) in oncology. This lecture is divided to the following parts: (1) Assessment of treatment response; (2) Treatment monitoring by PET: clinical examples; (3) PET for early response assessment; (4) Use of PET in Radiotherapy planning

'PET -Compton' system. Comparative evaluation with PET system using Monte Carlo simulation

International Nuclear Information System (INIS)

Diaz Garcia, Angelina; Arista Romeu, Eduardo; Abreu Alfonso, Yamiel; Leyva Fabelo, Antonio; Pinnera Hernandez, Ibrahin; Bolannos Perez, Lourdes; Rubio Rodriguez, Juan A; Perez Morales, Jose M.; Arce Dubois, Pedro; Vela Morales, Oscar; Willmott Zappacosta, Carlos

2011-01-01

Positron Emission Tomography (PET) in small animals has actually achieved spatial resolution round about 1 mm and currently there are under study different approaches to improve this spatial resolution. One of them combines PET technology with Compton Cameras. This paper presents the idea of the so called 'PET-Compton' systems and includes comparative evaluation of spatial resolution and global efficiency in both PET and PET-Compton system by means of Monte Carlo simulations using Geant4 code. Simulation is done on a PET-Compton system consisting of LYSO-LuYAP scintillating detectors of particular small animal PET scanner named 'Clear-PET' and for Compton detectors based on CdZnTe semiconductor. A group of radionuclides that emits a positron (e + ) and γ quantum almost simultaneously and fulfills some selection criteria for their possible use in PET-Compton systems for medical and biological applications were studied under simulation conditions. (Author)

PET imaging in breast cancer

International Nuclear Information System (INIS)

Bombardieri, E.; Crippa, F.

2001-01-01

The basis of tumour imaging with PET is a specific uptake mechanism of positron emitting radiopharmaceuticals. Among the potential tracers for breast cancer (fluorodeoxyglucose, methionine, tyrosine, fluoro-estradiol, nor-progesterone), 2-deoxy-2-fluoro-D-glucose labelled with fluorine (FDG) is the most widely used radiopharmaceutical because breast cancer is particularly avid of FDG and 18 F has the advantages of the a relatively long physical half-life. Mammography is the first choice examination in studying breast masses, due to its very good performances, an excellent compliance and the best value regarding the cost/effectiveness aspects. The FDG uptake in tissue correlates with the histological grade and potential aggressiveness of breast cancer and this may have prognostic consequences. Besides the evaluation of breast lesions, FDG-PET shows a great efficacy in staging lymph node involvement prior surgery and this could have a great value in loco-regional staging. Whole body PET provides also information with regard to metastasis localizations both in soft tissue and bone, and plays an important clinical role mainly in detecting recurrent metastatic disease. In fact for its metabolic characteristics PET visualizes regions of enhanced metabolic activity and can complete other imaging modalities based on structural anatomic changes. Even though CT and MRI show superior resolution characteristics, it has been demonstrated that PET provides more accurate information in discriminating between viable tumour, fibrotic scar or necrosis. These statements are coming from the examination of more than 2000 breast cancer detection

Tensile properties of interwoven hemp/PET (Polyethylene Terephthalate) epoxy hybrid composites

Science.gov (United States)

Ahmad, M. A. A.; Majid, M. S. A.; Ridzuan, M. J. M.; Firdaus, A. Z. A.; Amin, N. A. M.

2017-10-01

This paper describes the experimental investigation of the tensile properties of interwoven Hemp/PET hybrid composites. The effect of hybridization of hemp (warp) with PET fibres (weft) on tensile properties was of interest. Hemp and PET fibres were selected as the reinforcing material while epoxy resin was chosen as the matrix. The interwoven Hemp/PET fabric was used to produce hybrid composite using a vacuum infusion process. The tensile test was conducted using Universal Testing Machine in accordance to the ASTM D638. The tensile properties of the interwoven Hemp/PET hybrid composite were then compared with the neat woven hemp/epoxy composite. The results show that the strength of hemp/PET with the warp direction was increased by 8% compared to the neat woven hemp composite. This enhancement of tensile strength was due to the improved interlocking structure of interwoven Hemp/PET hybrid fabric.

PET-COMPTON System. Comparative evaluation with PET System using Monte Carlo Simulation

International Nuclear Information System (INIS)

Diaz Garcia, Angelina; Arista Romeu, Eduardo; Abreu Alfonso, Yamiel; Leyva Fabelo, Antonio; Pinnera HernAndez, Ibrahin; Bolannos Perez, Lourdes; Rubio Rodriguez, Juan A.; Perez Morales, Jose M.; Arce Dubois, Pedro; Vela Morales, Oscar; Willmott Zappacosta, Carlos

2012-01-01

Positron Emission Tomography (PET) in small animals has actually achieved spatial resolution round about 1 mm and currently there are under study different approaches to improve this spatial resolution. One of them combines PET technology with Compton Cameras. This paper presents the idea of the so called PET-Compton systems and has included comparative evaluation of spatial resolution and global efficiency in both PET and PET-Compton system by means of Monte Carlo simulations using Geant4 code. Simulation was done on a PET-Compton system made-up of LYSO-LuYAP scintillating detectors of particular small animal PET scanner named Clear-PET and for Compton detectors based on CdZnTe semiconductor. A group of radionuclides that emits a positron (e+) and quantum almost simultaneously and fulfills some selection criteria for their possible use in PET-Compton systems for medical and biological applications were studied under simulation conditions. By means of analytical reconstruction using SSRB (Single Slide Rebinning) method were obtained superior spatial resolution in PET-Compton system for all tested radionuclides (reaching sub-millimeter values of for 22Na source). However this analysis done by simulation have shown limited global efficiency values in PET-Compton system (in the order of 10 -5 -10 -6 %) instead of values around 5*10 -1 % that have been achieved in PET system. (author)

Fundamental Design Principles of Linear Collider Damping Rings, with an Application to CLIC

CERN Document Server

Potier, J P

2000-01-01

Damping Rings for Linear Colliders have to produce very small normalised emittances at a high repetition rate. A previous paper presented analytical expressions for the equilibrium emittance of an arc cell as a function of the deflection angle per dipole. In addition, an expression for the lattice parameters providing the minimum emittance, and a strategy to stay close to this, were proposed. This analytical approach is extended to the detailed design of Damping Rings, taking into account the straight sections and the damping wigglers. Complete rings, including wiggler and injection insections, were modelled with the MAD [1] program, and their performance was found to be in good agreement with the analytical calculation. With such an approach it is shown that a Damping Ring corresponding to the Compact Linear Collider (CLIC) parameters at 0.5 and 1 TeV centre-of-mass energy, and tunable for two different sets of emittance and injection repetition rate, can be designed using the same ring layout.

5,5'-Dithio-bis(2-nitrobenzoic acid) modification of cysteine improves the crystal quality of human chloride intracellular channel protein 2

International Nuclear Information System (INIS)

Mi Wei; Li Lanfen; Su Xiaodong

2008-01-01

Structural studies of human chloride intracellular channel protein 2 (CLIC2) had been hampered by the problem of generating suitable crystals primarily due to the protein containing exposed cysteines. Several chemical reagents were used to react with the cysteines on CLIC2 in order to modify the redox state of the protein. We have obtained high quality crystals that diffracted to better than 2.5 A at a home X-ray source by treating the protein with 5,5'-dithio-bis(2-nitrobenzoic acid) (DTNB). After solving the crystal structure of CLIC2, we found that the DTNB had reacted with the Cys 114 , and made CLIC2 in a homogenous oxidized state. This study demonstrated that the DTNB modification drastically improved the crystallization of CLIC2, and it implied that this method may be useful for other proteins containing exposed cysteines in general

Comparison of dosimetry between PET/CT and PET alone using 11C-ITMM

International Nuclear Information System (INIS)

Ito, Kimiteru; Sakata, Muneyuki; Wagarsuma, Kei; Toyohara, Jun; Ishibashi, Kenji; Ishii, Kenji; Ishiwata, Kiichi; Oda, Keiichi

2016-01-01

We used a new tracer, N-[4-[6-(isopropylamino) pyrimidin-4-yl]-1,3-thiazol-2-yl]-4- 11 C-methoxy-N-methylbenzamide ( 11 C-ITMM), to compare radiation doses from positron emission tomography (PET)/computed tomography (CT) with previously published doses from PET alone. Twelve healthy volunteers [six males (mean age ± SD, 27.7 ± 6.7 years) and six females (31.8 ± 14.5 years)] in 12 examinations were recruited. Dose estimations from PET/CT were compared with those from PET alone. Regions of interest (ROIs) in PET/CT were delineated on the basis of low-dose CT (LD-CT) images acquired during PET/CT. Internal and external radiation doses were estimated using OLINDA/EXM 1.0 and CT-Expo software. The effective dose (ED) for 11 C-ITMM calculated from PET/CT was estimated to be 4.7 ± 0.5 μSv/MBq for the male subjects and 4.1 ± 0.7 μSv/MBq for the female subjects. The mean ED for 11 C-ITMM calculated from PET alone in a previous report was estimated to be 4.6 ± 0.3 μSv/MBq (males, n = 3). The ED values for 11 C-ITMM calculated from PET/CT in the male subjects were almost identical to those from PET alone. The absorbed doses (ADs) of the gallbladder, stomach, red bone marrow, and spleen calculated from PET/CT were significantly different from those calculated from PET alone. The EDs of 11 C-ITMM calculated from PET/CT were almost identical to those calculated from PET alone. The ADs in several organs calculated from PET/CT differed from those from PET alone. LD-CT images acquired during PET/CT may facilitate organ identification.

Specific recommendations for accurate and direct use of PET-CT in PET guided radiotherapy for head and neck sites

Energy Technology Data Exchange (ETDEWEB)

Thomas, C. M., E-mail: christopher.thomas@gstt.nhs.uk; Convery, D. J.; Greener, A. G. [Guy' s and St. Thomas’ NHS Foundation Trust, Medical Physics Department, St. Thomas’ Hospital, London SE1 7EH (United Kingdom); Pike, L. C.; Baker, S.; Woods, E. [Division of Imaging Sciences and Biomedical Engineering, King' s College London, King' s Health Partners, St. Thomas’ Hospital, London SE1 7EH (United Kingdom); Hartill, C. E. [Guy' s and St. Thomas’ NHS Foundation Trust, Radiotherapy, Clinical Outpatients Clinic, St. Thomas’ Hospital, London SE1 7EH (United Kingdom)

2014-04-15

Purpose: To provide specific experience-based guidance and recommendations for centers wishing to develop, validate, and implement an accurate and efficient process for directly using positron emission tomography-computed tomography (PET-CT) for the radiotherapy planning of head and neck cancer patients. Methods: A PET-CT system was modified with hard-top couch, external lasers and radiotherapy immobilization and indexing devices and was subject to a commissioning and quality assurance program. PET-CT imaging protocols were developed specifically for radiotherapy planning and the image quality and pathway tested using phantoms and five patients recruited into an in-house study. Security and accuracy of data transfer was tested throughout the whole data pathway. The patient pathway was fully established and tested ready for implementation in a PET-guided dose-escalation trial for head and neck cancer patients. Results: Couch deflection was greater than for departmental CT simulator machines. An area of high attenuation in the couch generated image artifacts and adjustments were made accordingly. Using newly developed protocols CT image quality was suitable to maintain delineation and treatment accuracy. Upon transfer of data to the treatment planning system a half pixel offset between PET and CT was observed and corrected. By taking this into account, PET to CT alignment accuracy was maintained below 1 mm in all systems in the data pathway. Transfer of structures delineated in the PET fusion software to the radiotherapy treatment planning system was validated. Conclusions: A method to perform direct PET-guided radiotherapy planning was successfully validated and specific recommendations were developed to assist other centers. Of major concern is ensuring that the quality of PET and CT data is appropriate for radiotherapy treatment planning and on-treatment verification. Couch movements can be compromised, bore-size can be a limitation for certain immobilization

Specific recommendations for accurate and direct use of PET-CT in PET guided radiotherapy for head and neck sites

International Nuclear Information System (INIS)

Thomas, C. M.; Convery, D. J.; Greener, A. G.; Pike, L. C.; Baker, S.; Woods, E.; Hartill, C. E.

2014-01-01

Purpose: To provide specific experience-based guidance and recommendations for centers wishing to develop, validate, and implement an accurate and efficient process for directly using positron emission tomography-computed tomography (PET-CT) for the radiotherapy planning of head and neck cancer patients. Methods: A PET-CT system was modified with hard-top couch, external lasers and radiotherapy immobilization and indexing devices and was subject to a commissioning and quality assurance program. PET-CT imaging protocols were developed specifically for radiotherapy planning and the image quality and pathway tested using phantoms and five patients recruited into an in-house study. Security and accuracy of data transfer was tested throughout the whole data pathway. The patient pathway was fully established and tested ready for implementation in a PET-guided dose-escalation trial for head and neck cancer patients. Results: Couch deflection was greater than for departmental CT simulator machines. An area of high attenuation in the couch generated image artifacts and adjustments were made accordingly. Using newly developed protocols CT image quality was suitable to maintain delineation and treatment accuracy. Upon transfer of data to the treatment planning system a half pixel offset between PET and CT was observed and corrected. By taking this into account, PET to CT alignment accuracy was maintained below 1 mm in all systems in the data pathway. Transfer of structures delineated in the PET fusion software to the radiotherapy treatment planning system was validated. Conclusions: A method to perform direct PET-guided radiotherapy planning was successfully validated and specific recommendations were developed to assist other centers. Of major concern is ensuring that the quality of PET and CT data is appropriate for radiotherapy treatment planning and on-treatment verification. Couch movements can be compromised, bore-size can be a limitation for certain immobilization

Additional value of PET-CT in the staging of lung cancer: comparison with CT alone, PET alone and visual correlation of PET and CT

International Nuclear Information System (INIS)

Wever, W. de; Marchal, G.; Bogaert, J.; Verschakelen, J.A.; Ceyssens, S.; Mortelmans, L.; Stroobants, S.

2007-01-01

Integrated positron emission tomography (PET) and computed tomography (CT) is a new imaging modality offering anatomic and metabolic information. The purpose was to evaluate retrospectively the accuracy of integrated PET-CT in the staging of a suggestive lung lesion, comparing this with the accuracy of CT alone, PET alone and visually correlated PET-CT. Fifty patients undergoing integrated PET-CT for staging of a suggestive lung lesion were studied. Their tumor, node, metastasis (TNM) statuses were determined with CT, PET, visually correlated PET-CT and integrated PET-CT. These TNM stages were compared with the surgical TNM status. Integrated PET-CT was the most accurate imaging technique in the assessment of the TNM status. Integrated PET-CT predicted correctly the T status, N status, M status and TNM status in, respectively, 86%, 80%, 98%, 70% versus 68%, 66%,88%, 46% with CT, 46%, 70%, 96%, 30% with PET and 72%, 68%, 96%, 54% with visually correlated PET-CT. T status and N status were overstaged, respectively, in 8% and 16% with integrated PET-CT, in 20% and 28% with CT, in 16% and 20% with PET, in 12% and 20% with visually correlated PET-CT and understaged in 6% and 4% with integrated PET-CT, versus 12% and 6% with CT, 38% and 10% with PET and 12% with visually correlated PET-CT. Integrated PET-CT improves the staging of lung cancer through a better anatomic localization and characterization of lesions and is superior to CT alone and PET alone. If this technique is not available, visual correlation of PET and CT can be a valuable alternative. (orig.)

Pet-Related Infections.

Science.gov (United States)

Day, Michael J

2016-11-15

Physicians and veterinarians have many opportunities to partner in promoting the well-being of people and their pets, especially by addressing zoonotic diseases that may be transmitted between a pet and a human family member. Common cutaneous pet-acquired zoonoses are dermatophytosis (ringworm) and sarcoptic mange (scabies), which are both readily treated. Toxoplasmosis can be acquired from exposure to cat feces, but appropriate hygienic measures can minimize the risk to pregnant women. Persons who work with animals are at increased risk of acquiring bartonellosis (e.g., cat-scratch disease); control of cat fleas is essential to minimize the risk of these infections. People and their pets share a range of tick-borne diseases, and exposure risk can be minimized with use of tick repellent, prompt tick removal, and appropriate tick control measures for pets. Pets such as reptiles, amphibians, and backyard poultry pose a risk of transmitting Salmonella species and are becoming more popular. Personal hygiene after interacting with these pets is crucial to prevent Salmonella infections. Leptospirosis is more often acquired from wildlife than infected dogs, but at-risk dogs can be protected with vaccination. The clinical history in the primary care office should routinely include questions about pets and occupational or other exposure to pet animals. Control and prevention of zoonoses are best achieved by enhancing communication between physicians and veterinarians to ensure patients know the risks of and how to prevent zoonoses in themselves, their pets, and other people.

3D Surface Realignment Tracking for Medical Imaging: A Phantom Study with PET Motion Correction

DEFF Research Database (Denmark)

Olesen, Oline Vinter; Paulsen, Rasmus Reinhold; Jensen, Rasmus Ramsbøl

2011-01-01

We present a complete system for motion correction in high resolution brain positron emission tomography (PET) imaging. It is based on a compact structured light scanner mounted above the patient tunnel of the Siemens High Resolution Research Tomograph PET brain scanner. The structured light system...... is equipped with a near infrared diode and uses phase-shift interferometry to compute 3D representations of the forehead of the patient. These 3D point clouds are progressively aligned to a reference surface and thereby giving the head pose changes. The estimated pose changes are used to reposition a sequence...... of recon- structed PET frames. To align the structured light system with the PET coordinate system a novel registration algorithm based on the PET trans- mission scan and an initial surface has been developed. The performance of the complete setup has been evaluated using a custom made phantom based...

PET and PET-CT. State of the art and future prospects

International Nuclear Information System (INIS)

Fanti, Stefano; Franchi, Roberto; Battista, Giuseppe; Monetti, Nino; Canini, Romeo

2005-01-01

Fluoro-deoxyglucose positron emission tomography (FDG PET) enables the in vivo study of tissue metabolism, and thus is able to identify malignant tumours as hypermetabolic lesions by an increase in tracer uptake. Many papers have demonstrated both the relevant impact of FDG PET on staging of many cancers and the superior accuracy of the technique compared with conventional diagnostic methods for pre-treatment evaluation, therapy response evaluation and relapse identification. In particular PET was found useful in identifying lymph nodal and metastatic spread. thus altering patient management in more than 30% of cases. PET images, however, provide limited anatomical data, which in regions such as the head and neck, mediastinum and pelvic cavity is a significant drawback. The exact localization of lesions may also be difficult in some cases, on the basis of PET images alone. The introduction of combined PET-computed tomography (PET-CT) scanners enables the almost simultaneous acquisition of transmission and emission images, thus obtaining optimal fusion images in a very short time. PET-CT fusion images enable lesions to be located, reducing false positive studies and increasing accuracy; the overall duration of examination may also be reduced. On the basis of both literature data and our experience we established the clinical indications when PET-CT may be particularly useful, in comparison with PET alone. It should also be underlined that the use of PET-CT is almost mandatory for new traces such as C-choline and C-methionine; these new tracers may be applied for studying tumours not assessable with FDG, such as prostate cancer. In conclusion PET-CT is at present the most advanced method for metabolic imaging, and is capable of precisely localizing and assessing tumours; fusion images reduce false positive and inconclusive studies, thus increasing diagnostic accuracy [it

Development of PET insert for simultaneous PET/MR imaging of human brain

Energy Technology Data Exchange (ETDEWEB)

Jung, Jiwoong; Choi, Yong; Jung, Jin Ho; Kim, Sangsu; Im, Ki Chun; Lim, Hyun Keong [Molecular Imaging Research & Education (MiRe) Laboratory, Department of Electronic Engineering, Sogang University, Seoul (Korea, Republic of); Oh, Changheun; Park, HyunWook; Cho, Gyuseong [Departments of Electrical Engineering and Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon (Korea, Republic of)

2014-07-29

Recently, there has been great interest on the development of combined PET/MR, which is a useful tool for both functional and anatomic imaging. The purpose of this study was to develop a MR compatible PET insert for simultaneous PET and MR imaging of human brain and to evaluate the performance of the hybrid PET-MRI. The PET insert consisted of 18 detector blocks arranged in a ring of 390 mm diameter with 60 mm axial FOV. Each detector block was composed of 4 × 4 matrix of detector modules, each of which consisted of a 4 × 4 array LYSO coupled to a 4 × 4 GAPD array. The PET gantry was shielded with gold-plated conductive fabric tapes. The charge signals of PET detector transferred via 4 m long flat cables were fed into the position decoder circuits (PDCs) and then transferred to FPGA-embedded DAQ modules. The PDCs and DAQ modules were enclosed in an aluminum box and located at the rear of the MR bore inside MRI room. 3-T human MRIs of two different vendors were used to evaluate the MR compatibility of developed PET insert. No significant changes of the PET performance and the homogeneity of MR images caused by the non-compatibility of PET-MRI were observed with the 2 different MRIs. The signal intensities of MR images were slightly degraded (<3.6%) with the both MRI systems. The difference between independently and simultaneously acquired PET images of brain phantom was negligibly small (<4.3%). High quality simultaneous brain PET and MRI of 3 normal volunteers were successfully acquired. Experimental results indicate that the high performance compact and lightweight PET insert for hybrid PET/MRI, which could be utilized with the MRI from various manufactures, can be developed using GAPD arrays and charge signal transmission method proposed in this study.

Beam dynamics studies and emittance optimization in the CTF3 linac at CERN

CERN Document Server

Urschütz, Peter; Corsini, Roberto; Döbert, Steffen; Ferrari, Arnaud; Tecker, Frank

2006-01-01

Small transverse beam emittances and well-known lattice functions are crucial for the 30 GHz power production in the Power Extraction and Transfer Structure (PETS) and for the commissioning of the Delay Loop of the CLIC Test Facility 3 (CTF3). Following beam dynamics simulation results, two additional solenoids were installed in the CTF3 injector in order to improve the emittance. During the runs in 2005 and 2006, an intensive measurement campaign to determine Twiss parameters and beam sizes was launched. The results obtained by means of quadrupole scans for different modes of operation suggest emittances well below the nominal .n,rms = 100 ?Î?Êm and a good agreement with PARMELA simulations.

PET/MRI and PET/CT in advanced gynaecological tumours: initial experience and comparison

Energy Technology Data Exchange (ETDEWEB)

Queiroz, Marcelo A.; Schulthess, Gustav von; Veit-Haibach, Patrick [University Hospital Zurich, Department Medical Radiology, Nuclear Medicine, Zurich (Switzerland); University Hospital Zurich, Department Medical Radiology, Diagnostic and Interventional Radiology, Zurich (Switzerland); University of Zurich, Zurich (Switzerland); Kubik-Huch, Rahel A.; Freiwald-Chilla, Bianka [Kantonsspital Baden AG, Department of Radiology, Baden (Switzerland); Hauser, Nik [Kantonsspital Baden AG, Department of Gynaecology, Baden (Switzerland); Froehlich, Johannes M. [Guerbet AG, Zurich (Switzerland)

2015-08-15

To compare the diagnostic accuracy of PET/MRI and PET/CT for staging and re-staging advanced gynaecological cancer patients as well as identify the potential benefits of each method in such a population. Twenty-six patients with suspicious or proven advanced gynaecological cancer (12 ovarian, seven cervical, one vulvar and four endometrial tumours, one uterine metastasis, and one primary peritoneal cancer) underwent whole-body imaging with a sequential trimodality PET/CT/MR system. Images were analysed regarding primary tumour detection and delineation, loco-regional lymph node staging, and abdominal/extra-abdominal distant metastasis detection (last only by PET/CT). Eighteen (69.2 %) patients underwent PET/MRI for primary staging and eight patients (30.8 %) for re-staging their gynaecological malignancies. For primary tumour delineation, PET/MRI accuracy was statistically superior to PET/CT (p < 0.001). Among the different types of cancer, PET/MRI presented better tumour delineation mainly for cervical (6/7) and endometrial (2/3) cancers. PET/MRI for local evaluation as well as PET/CT for extra-abdominal metastases had therapeutic consequences in three and one patients, respectively. PET/CT detected 12 extra-abdominal distant metastases in 26 patients. PET/MRI is superior to PET/CT for primary tumour delineation. No differences were found in detection of regional lymph node involvement and abdominal metastases detection. (orig.)

Comparative analysis of PET/CT and PET/MR image characteristics of head and neck squamous cell carcinoma%对比分析头颈部鳞状细胞癌PET/CT与PET/MR特征

Institute of Scientific and Technical Information of China (English)

白乐; 程勇; 唐勇进; 凌雪英

2017-01-01

Objective To investigate PET/CT and PET/MR characteristics of head and neck squamous cell carcinoma (HNSCC).Methods Totally 40 patients with HNSCC underwent whole body 18F-FDG PET/CT and MR scans of head and neck before anti-tumor treatment.PET positive lesions of HNSCC,including primary lesions and lymph nodes were evaluated by 2 radiologists independently.Then the imaging quality,fusion quality,lesion conspicuity and lesion characteristics were assessed based on PET/CT,PET/MR T1WI and PET/MR T2WI.Results Ninety PET positive lesions in all 40patients were evaluated,including 40 primary lesions and 50 lymph nodes.Similar imaging quality and fusion quality of PET/CT,PET/MR T1WI and PET/MR T2WI were obtained without statistical difference (both P＞0.05).For the lesion conspicuity,PET/MR T1WI and PET/MR T2WI demonstrated significantly better than PET/CT in positive primary lesions and lymph nodes (all P＜0.05).For the characteristics of positive primary lesions,PET/MR T2WI provided more information than PET/CT in 29 lesions,equal to PET/CT in 4 lesions,and less than PET/CT in 7 lesions.Conclusion The application of PET/MR in HNSCC is feasible,being superior to PET/CT in indication of lesions in head and neck area.%目的 探讨头颈部鳞状细胞癌(HNSCC)的PET/CT及PET/MR特征.方法 纳入未经抗肿瘤治疗的头颈部鳞状细胞癌患者40例,所有患者均接受PET/CT及头颈部MR检查.由2名观察者独立观察PET阳性病灶,包括阳性原发灶及阳性淋巴结;并对PET/CT、PET/MR T1WI及PET/MR T2WI的图像质量、融合准确度、病灶清晰度、病灶特征等进行评分.分析2名观察者间的一致性.结果 40例患者共90个PET阳性病灶,包括阳性原发灶40个、阳性淋巴结50个.PET/CT、PET/MR T1WI及PET/MR T2WI在图像质量及融合准确度方面差异均无统计学意义(P均＞0.05);在显示阳性原发灶及阳性淋巴结的清晰度方面,PET/MR T1WI及PET/MR T2WI均优于PET/CT(P均＜0.05).40个阳性原发灶中,PET

Present and future of PET and PET/CT in gynaecologic malignancies

International Nuclear Information System (INIS)

Musto, Alessandra; Rampin, Lucia; Nanni, Cristina; Marzola, Maria Cristina; Fanti, Stefano; Rubello, Domenico

2011-01-01

Objectives: To review the published data in literature on patients affected by gynaecological malignancies to establish the role of 18 F-FDG positron emission tomography (PET) and PET/CT in comparison to conventional imaging (CI). Materials and methods: All papers specifically addressed to the role of 18 F-FDG PET and PET/CT in gynaecological malignancies published on PubMed/Medline, in abstracts from the principal international congresses, in the guidelines from national Societies that had appeared in literature until November 2009 were considered for the purpose of the present study. Results and conclusions: The use of 18 F-FDG PET, and even more of 18 F-FDG PET/CT, is increasing in the follow up of patients with gynaecologic malignancies and suspected recurrent disease: there is evidence in the literature that 18 F-FDG PET/CT has a higher sensitivity than CI in depicting occult metastatic spread. An interesting issue is represented by patients with ovarian cancer with an increase of the specific biomarker, CA-125, and negative/inconclusive findings at CI. The use of 18 F-FDG PET in differential diagnosis and staging is more controversial, but there is some evidence that a baseline PET examination performed before commencing therapy, for staging purpose, is also useful to evaluate the response to chemoradiation treatment. In several papers it has been suggested a relevant role of 18 F-FDG PET/CT in evaluating the entity of response to treatment and therefore to plan the subsequent therapeutic strategy.

MR-guided joint reconstruction of activity and attenuation in brain PET-MR

DEFF Research Database (Denmark)

Mehranian, Abolfazl; Zaidi, Habib; Reader, Andrew J

2017-01-01

by unknown scaling factors. We recently demonstrated that in hybrid PET-MR, the scaling issue of this algorithm can be effectively addressed by imposing MR spatial constraints on the estimation of attenuation maps using a penalized MLAA (P-MLAA(+)) algorithm. With the advent of simultaneous PET-MR systems......, MRI-guided PET image reconstruction has also gained attention for improving the quantitative accuracy of PET images, usually degraded by noise and partial volume effects. The aim of this study is therefore to increase the benefits of MRI information for improving the quantitative accuracy of PET...... as a reference. The simulation results showed that the proposed method can notably improve the visual quality of the PET images by reducing noise while preserving structural boundaries and at the same time improving the quantitative accuracy of the PET images. Our clinical reconstruction results showed...

Measurement of the branching ratios for the Standard Model Higgs decays into muon pairs and into Z boson pairs at a 1.4 TeV CLIC

CERN Document Server

AUTHOR|(SzGeCERN)701211; Bozovic-Jelisavcic, Ivanka; Grefe, Christian; Kacarevic, Goran; Lukic, Strahinja; Pandurovic, Mila; Roloff, Philipp Gerhard; Smiljanic, Ivan

2016-01-01

The measurement of the Higgs production cross-section times the branching ratios for its decays into μ+μ- and ZZ* pairs at a 1.4 TeV CLIC collider is investigated in this paper. The Standard Model Higgs boson with a mass of 126 GeV is dominantly produced via WW fusion in e+e- collisions at 1.4 TeV centre-of-mass energy. Analyses for both decay channels are based on a full simulation of the CLIC_ILD detector. All relevant physics and beam-induced background processes are taken into account. An integrated luminosity of 1.5 ab 1 and unpolarised beams are assumed. For the H-->ZZ* decay, the purely hadronic final state (ZZ*--> qq ̄qq ̄) is considered as well as ZZ* decays into two jets and two leptons (ZZ*--> qq ̄l+l- ). It is shown that the branching ratio for the Higgs decay into a muon pair times the Higgs production cross-section can be measured with 38% statistical uncertainty. It is also shown that the statistical uncertainty of the Higgs branching fraction for decay into a Z boson pair times the Hi...

Head and neck imaging with PET and PET/CT: artefacts from dental metallic implants

International Nuclear Information System (INIS)

Goerres, Gerhard W.; Hany, Thomas F.; Kamel, Ehab; Schulthess von, Gustav K.; Buck, Alfred

2002-01-01

Germanium-68 based attenuation correction (PET Ge68 ) is performed in positron emission tomography (PET) imaging for quantitative measurements. With the recent introduction of combined in-line PET/CT scanners, CT data can be used for attenuation correction. Since dental implants can cause artefacts in CT images, CT-based attenuation correction (PET CT ) may induce artefacts in PET images. The purpose of this study was to evaluate the influence of dental metallic artwork on the quality of PET images by comparing non-corrected images and images attenuation corrected by PET Ge68 and PET CT . Imaging was performed on a novel in-line PET/CT system using a 40-mAs scan for PET CT in 41 consecutive patients with high suspicion of malignant or inflammatory disease. In 17 patients, additional PET Ge68 images were acquired in the same imaging session. Visual analysis of fluorine-18 fluorodeoxyglucose (FDG) distribution in several regions of the head and neck was scored on a 4-point scale in comparison with normal grey matter of the brain in the corresponding PET images. In addition, artefacts adjacent to dental metallic artwork were evaluated. A significant difference in image quality scoring was found only for the lips and the tip of the nose, which appeared darker on non-corrected than on corrected PET images. In 33 patients, artefacts were seen on CT, and in 28 of these patients, artefacts were also seen on PET imaging. In eight patients without implants, artefacts were seen neither on CT nor on PET images. Direct comparison of PET Ge68 and PET CT images showed a different appearance of artefacts in 3 of 17 patients. Malignant lesions were equally well visible using both transmission correction methods. Dental implants, non-removable bridgework etc. can cause artefacts in attenuation-corrected images using either a conventional 68 Ge transmission source or the CT scan obtained with a combined PET/CT camera. We recommend that the non-attenuation-corrected PET images also be

An investigation on the use of shredded waste PET bottles as aggregate in lightweight concrete

International Nuclear Information System (INIS)

Akcaoezoglu, Semiha; Atis, Cengiz Duran; Akcaoezoglu, Kubilay

2010-01-01

In this work, the utilization of shredded waste Poly-ethylene Terephthalate (PET) bottle granules as a lightweight aggregate in mortar was investigated. Investigation was carried out on two groups of mortar samples, one made with only PET aggregates and, second made with PET and sand aggregates together. Additionally, blast-furnace slag was also used as the replacement of cement on mass basis at the replacement ratio of 50% to reduce the amount of cement used and provide savings. The water-binder (w/b) ratio and PET-binder (PET/b) ratio used in the mixtures were 0.45 and 0.50, respectively. The size of shredded PET granules used in the preparation of mortar mixtures were between 0 and 4 mm. The results of the laboratory study and testing carried out showed that mortar containing only PET aggregate, mortar containing PET and sand aggregate, and mortars modified with slag as cement replacement can be drop into structural lightweight concrete category in terms of unit weight and strength properties. Therefore, it was concluded that there is a potential for the use of shredded waste PET granules as aggregate in the production of structural lightweight concrete. The use of shredded waste PET granules due to its low unit weight reduces the unit weight of concrete which results in a reduction in the death weight of a structural concrete member of a building. Reduction in the death weight of a building will help to reduce the seismic risk of the building since the earthquake forces linearly dependant on the dead-weight. Furthermore, it was also concluded that the use of industrial wastes such as PET granules and blast-furnace slag in concrete provides some advantages, i.e., reduction in the use of natural resources, disposal of wastes, prevention of environmental pollution, and energy saving.

An investigation on the use of shredded waste PET bottles as aggregate in lightweight concrete.

Science.gov (United States)

Akçaözoğlu, Semiha; Atiş, Cengiz Duran; Akçaözoğlu, Kubilay

2010-02-01

In this work, the utilization of shredded waste Poly-ethylene Terephthalate (PET) bottle granules as a lightweight aggregate in mortar was investigated. Investigation was carried out on two groups of mortar samples, one made with only PET aggregates and, second made with PET and sand aggregates together. Additionally, blast-furnace slag was also used as the replacement of cement on mass basis at the replacement ratio of 50% to reduce the amount of cement used and provide savings. The water-binder (w/b) ratio and PET-binder (PET/b) ratio used in the mixtures were 0.45 and 0.50, respectively. The size of shredded PET granules used in the preparation of mortar mixtures were between 0 and 4 mm. The results of the laboratory study and testing carried out showed that mortar containing only PET aggregate, mortar containing PET and sand aggregate, and mortars modified with slag as cement replacement can be drop into structural lightweight concrete category in terms of unit weight and strength properties. Therefore, it was concluded that there is a potential for the use of shredded waste PET granules as aggregate in the production of structural lightweight concrete. The use of shredded waste PET granules due to its low unit weight reduces the unit weight of concrete which results in a reduction in the death weight of a structural concrete member of a building. Reduction in the death weight of a building will help to reduce the seismic risk of the building since the earthquake forces linearly dependent on the dead-weight. Furthermore, it was also concluded that the use of industrial wastes such as PET granules and blast-furnace slag in concrete provides some advantages, i.e., reduction in the use of natural resources, disposal of wastes, prevention of environmental pollution, and energy saving.

{sup 18}F-FDG PET and PET/CT in Burkitt's lymphoma

Energy Technology Data Exchange (ETDEWEB)

Karantanis, Dimitrios, E-mail: dkarantanis@nuclmed.ne [Division of Nuclear Medicine, Department of Radiology, Mayo Clinic, Rochester, MN (United States); Durski, Jolanta M.; Lowe, Val J.; Nathan, Mark A.; Mullan, Brian P. [Division of Nuclear Medicine, Department of Radiology, Mayo Clinic, Rochester, MN (United States); Georgiou, Evangelos [Medical Physics Department, Medical School, University of Athens (Greece); Johnston, Patrick B. [Division of Hematology, Department of Medicine, Mayo Clinic, Rochester, MN (United States); Wiseman, Gregory A. [Division of Nuclear Medicine, Department of Radiology, Mayo Clinic, Rochester, MN (United States)

2010-07-15

Objective: To explore the value of {sup 18}F fluorodeoxy-glucose (FDG) positron emission tomography (PET) in Burkitt's lymphoma. Methods: All Burkitt's lymphoma patients referred for FDG PET or FDG PET/computed tomography (CT) exams at our institution from June 2003 to June 2006 were included. Selected patients were followed and clinical information was reviewed retrospectively. Results from FDG PET-PET/CT, as blindly reviewed by a consensus of two experienced readers, were compared with the status of the disease as determined by other laboratory, clinical and imaging exams and clinical follow-up. FDG PET-PET/CT results were classified as true positive or negative and false positive or negative. The degree of FDG uptake in the positive lesions was semiquantified as maximum standard uptake value (SUVmax). Results: Fifty-seven FDG PET-PET/CT exams were done in 15 patients. Seven exams were done for initial staging, 8 during and 14 after the completion of therapy, and 28 for disease surveillance. For nodal disease FDG PET-PET/CT was true positive in 8, true negative in 47 and false positive in 2 exams (sensitivity 100%, specificity 96%). For extranodal disease FDG PET-PET/CT was true positive in 6, true negative in 48 and false positive in 3 exams (sensitivity 100%, specificity 94%). The mean SUVmax for the positive nodal lesions was 15.7 (range 6.9-21.7, median 18.5) and for extranodal lesions was 14.2 (range 6.2-24.3, median 12.4). Conclusions: FDG PET-PET/CT is sensitive for the detection of viable disease in Burkitt's lymphoma. Affected areas demonstrated high degree of uptake that was reversible upon successful implementation of treatment.

Standardised uptake values from PET/CT images: comparison with conventional attenuation-corrected PET

International Nuclear Information System (INIS)

Souvatzoglou, M.; Ziegler, S.I.; Martinez, M.J.; Dzewas, G.; Schwaiger, M.; Bengel, F.; Busch, R.

2007-01-01

In PET/CT, CT-derived attenuation factors may influence standardised uptake values (SUVs) in tumour lesions and organs when compared with stand-alone PET. Therefore, we compared PET/CT-derived SUVs intra-individually in various organs and tumour lesions with stand-alone PET-derived SUVs. Thirty-five patients with known or suspected cancer were prospectively included. Sixteen patients underwent FDG PET using an ECAT HR+scanner, and subsequently a second scan using a Biograph Sensation 16PET/CT scanner. Nineteen patients were scanned in the reverse order. All images were reconstructed with an iterative algorithm (OSEM). Suspected lesions were grouped as paradiaphragmatic versus distant from the diaphragm. Mean and maximum SUVs were also calculated for brain, lung, liver, spleen and vertebral bone. The attenuation coefficients (μ values) used for correction of emission data (bone, soft tissue, lung) in the two data sets were determined. A body phantom containing six hot spheres and one cold cylinder was measured using the same protocol as in patients. Forty-six lesions were identified. There was a significant correlation of maximum and mean SUVs derived from PET and PET/CT for 14 paradiaphragmatic lesions (r=0.97 respectively; p<0.001 respectively) and for 32 lesions located distant from the diaphragm (r=0.87 and r=0.89 respectively; p<0.001 respectively). No significant differences were observed in the SUVs calculated with PET and PET/CT in the lesions or in the organs. In the phantom, radioactivity concentration in spheres calculated from PET and from PET/CT correlated significantly (r=0.99; p<0.001). SUVs of cancer lesions and normal organs were comparable between PET and PET/CT, supporting the usefulness of PET/CT-derived SUVs for quantification of tumour metabolism. (orig.)

Present and future of PET and PET/CT in gynaecologic malignancies

Energy Technology Data Exchange (ETDEWEB)

Musto, Alessandra [Department of Nuclear Medicine, PET Center, Policlinico Sant' Orsola Malpighi, Bologna University, Bologna (Italy); Rampin, Lucia [Department of Nuclear Medicine, PET Center, Radiology, Medical Physics, Santa Maria della Misericordia Hospital, viale tre martiri 140, 45100 Rovigo (Italy); Nanni, Cristina [Department of Nuclear Medicine, PET Center, Policlinico Sant' Orsola Malpighi, Bologna University, Bologna (Italy); Marzola, Maria Cristina [Department of Nuclear Medicine, PET Center, Radiology, Medical Physics, Santa Maria della Misericordia Hospital, viale tre martiri 140, 45100 Rovigo (Italy); Fanti, Stefano [Department of Nuclear Medicine, PET Center, Policlinico Sant' Orsola Malpighi, Bologna University, Bologna (Italy); Rubello, Domenico, E-mail: domenico.rubello@libero.it [Department of Nuclear Medicine, PET Center, Radiology, Medical Physics, Santa Maria della Misericordia Hospital, viale tre martiri 140, 45100 Rovigo (Italy)

2011-04-15

Objectives: To review the published data in literature on patients affected by gynaecological malignancies to establish the role of {sup 18}F-FDG positron emission tomography (PET) and PET/CT in comparison to conventional imaging (CI). Materials and methods: All papers specifically addressed to the role of {sup 18}F-FDG PET and PET/CT in gynaecological malignancies published on PubMed/Medline, in abstracts from the principal international congresses, in the guidelines from national Societies that had appeared in literature until November 2009 were considered for the purpose of the present study. Results and conclusions: The use of {sup 18}F-FDG PET, and even more of {sup 18}F-FDG PET/CT, is increasing in the follow up of patients with gynaecologic malignancies and suspected recurrent disease: there is evidence in the literature that {sup 18}F-FDG PET/CT has a higher sensitivity than CI in depicting occult metastatic spread. An interesting issue is represented by patients with ovarian cancer with an increase of the specific biomarker, CA-125, and negative/inconclusive findings at CI. The use of {sup 18}F-FDG PET in differential diagnosis and staging is more controversial, but there is some evidence that a baseline PET examination performed before commencing therapy, for staging purpose, is also useful to evaluate the response to chemoradiation treatment. In several papers it has been suggested a relevant role of {sup 18}F-FDG PET/CT in evaluating the entity of response to treatment and therefore to plan the subsequent therapeutic strategy.

Quantitative and Visual Assessments toward Potential Sub-mSv or Ultrafast FDG PET Using High-Sensitivity TOF PET in PET/MRI.

Science.gov (United States)

Behr, Spencer C; Bahroos, Emma; Hawkins, Randall A; Nardo, Lorenzo; Ravanfar, Vahid; Capbarat, Emily V; Seo, Youngho

2018-06-01

Newer high-performance time-of-flight (TOF) positron emission tomography (PET) systems have the capability to preserve diagnostic image quality with low count density, while maintaining a high raw photon detection sensitivity that would allow for a reduction in injected dose or rapid data acquisition. To assess this, we performed quantitative and visual assessments of the PET images acquired using a highly sensitive (23.3 cps/kBq) large field of view (25-cm axial) silicon photomultiplier (SiPM)-based TOF PET (400-ps timing resolution) integrated with 3 T-MRI in comparison to PET images acquired on non-TOF PET/x-ray computed tomography (CT) systems. Whole-body 2-deoxy-2-[ 18 F]fluoro-D-glucose ([ 18 F]FDG) PET/CT was acquired for 15 patients followed by whole body PET/magnetic resonance imaging (MRI) with an average injected dose of 325 ± 84 MBq. The PET list mode data from PET/MRI were reconstructed using full datasets (4 min/bed) and reduced datasets (2, 1, 0.5, and 0.25 min/bed). Qualitative assessment between PET/CT and PET/MR images were made. A Likert-type scale between 1 and 5, 1 for non-diagnostic, 3 equivalent to PET/CT, and 5 superior quality, was used. Maximum and mean standardized uptake values (SUV max and SUV mean ) of normal tissues and lesions detected were measured and compared. Mean visual assessment scores were 3.54 ± 0.32, 3.62 ± 0.38, and 3.69 ± 0.35 for the brain and 3.05 ± 0.49, 3.71 ± 0.45, and 4.14 ± 0.44 for the whole-body maximum intensity projections (MIPs) for 1, 2, and 4 min/bed PET/MR images, respectively. The SUV mean values for normal tissues were lower and statistically significant for images acquired at 4, 2, 1, 0.5, and 0.25 min/bed on the PET/MR, with values of - 18 ± 28 % (p PET/MR datasets. High-sensitivity TOF PET showed comparable but still better visual image quality even at a much reduced activity in comparison to lower-sensitivity non-TOF PET. Our data translates to a seven times

Imaging with 124I in differentiated thyroid carcinoma: is PET/MRI superior to PET/CT?

International Nuclear Information System (INIS)

Binse, I.; Poeppel, T.D.; Ruhlmann, M.; Gomez, B.; Bockisch, A.; Rosenbaum-Krumme, S.J.; Umutlu, L.

2016-01-01

The aim of this study was to compare integrated PET/CT and PET/MRI for their usefulness in detecting and categorizing cervical iodine-positive lesions in patients with differentiated thyroid cancer using 124 I as tracer. The study group comprised 65 patients at high risk of iodine-positive metastasis who underwent PET/CT (low-dose CT scan, PET acquisition time 2 min; PET/CT 2 ) followed by PET/MRI of the neck 24 h after 124 I administration. PET images from both modalities were analysed for the numbers of tracer-positive lesions. Two different acquisition times were used for the comparisons, one matching the PET/CT 2 acquisition time (2 min, PET/MRI 2 ) and the other covering the whole MRI scan time (30 min, PET/MRI 30 ). Iodine-positive lesions were categorized as metastasis, thyroid remnant or inconclusive according to their location on the PET/CT images. Morphological information provided by MRI was considered for evaluation of lesions on PET/MRI and for volume information. PET/MRI 2 detected significantly more iodine-positive metastases and thyroid remnants than PET/CT 2 (72 vs. 60, p = 0.002, and 100 vs. 80, p = 0.001, respectively), but the numbers of patients with at least one tumour lesion identified were not significantly different (21/65 vs. 17/65 patients). PET/MRI 30 tended to detect more PET-positive metastases than PET/MRI 2 (88 vs. 72), but the difference was not significant (p = 0.07). Of 21 lesions classified as inconclusive on PET/CT, 5 were assigned to metastasis or thyroid remnant when evaluated by PET/MRI. Volume information was available in 34 % of iodine-positive metastases and 2 % of thyroid remnants on PET/MRI. PET/MRI of the neck was found to be superior to PET/CT in detecting iodine-positive lesions. This was attributed to the higher sensitivity of the PET component, Although helpful in some cases, we found no substantial advantage of PET/MRI over PET/CT in categorizing iodine-positive lesions as either metastasis or thyroid remnant

A quality system for PET: An industry perspective

International Nuclear Information System (INIS)

Zigler, Steven S.; Breslow, Kenneth; Nazerias, Michael

2005-01-01

Quality systems have been employed in a variety of industries to develop and supply products that meet customer expectations and regulatory requirements. Most quality systems address organizational structure, design controls, production, complaints, audits, corrective actions and preventive actions. This paper describes PETNET's efforts to develop a quality system for use in the production of PET tracers. Our goal is to ensure quality products and to facilitate compliance with impending PET good manufacturing practice (GMP) regulations

Magnetic Resonance-based Motion Correction for Quantitative PET in Simultaneous PET-MR Imaging.

Science.gov (United States)

Rakvongthai, Yothin; El Fakhri, Georges

2017-07-01

Motion degrades image quality and quantitation of PET images, and is an obstacle to quantitative PET imaging. Simultaneous PET-MR offers a tool that can be used for correcting the motion in PET images by using anatomic information from MR imaging acquired concurrently. Motion correction can be performed by transforming a set of reconstructed PET images into the same frame or by incorporating the transformation into the system model and reconstructing the motion-corrected image. Several phantom and patient studies have validated that MR-based motion correction strategies have great promise for quantitative PET imaging in simultaneous PET-MR. Copyright © 2017 Elsevier Inc. All rights reserved.

Simulations and Vacuum Tests of a CLIC Accelerating Structure

CERN Document Server

Garion, C

2011-01-01

The Compact LInear Collider, under study, is based on room temperature high gradient structures. The vacuum specificities of these cavities are low conductance, large surface areas and a non-baked system. The main issue is to reach UHV conditions (typically 10-7 Pa) in a system where the residual vacuum is driven by water outgassing. A finite element model based on an analogy thermal/vacuum has been built to estimate the vacuum profile in an accelerating structure. Vacuum tests are carried out in a dedicated set-up, the vacuum performances of different configurations are presented and compared with the predictions.

Sensory analysis of pet foods.

Science.gov (United States)

Koppel, Kadri

2014-08-01

Pet food palatability depends first and foremost on the pet and is related to the pet food sensory properties such as aroma, texture and flavor. Sensory analysis of pet foods may be conducted by humans via descriptive or hedonic analysis, pets via acceptance or preference tests, and through a number of instrumental analysis methods. Sensory analysis of pet foods provides additional information on reasons behind palatable and unpalatable foods as pets lack linguistic capabilities. Furthermore, sensory analysis may be combined with other types of information such as personality and environment factors to increase understanding of acceptable pet foods. Most pet food flavor research is proprietary and, thus, there are a limited number of publications available. Funding opportunities for pet food studies would increase research and publications and this would help raise public awareness of pet food related issues. This mini-review addresses current pet food sensory analysis literature and discusses future challenges and possibilities. © 2014 Society of Chemical Industry.

The application of PET and PET-CT in cervical cancer

International Nuclear Information System (INIS)

Huang Jianmin; Pan Liping; Li Dongxue

2007-01-01

Cervical cancer is the common malignancies in woman, 18 F-fluorodeoxyglucose ( 18 F-FDG) PET is a well-established method for detecting, staging, cancer recurrence, therapeutic response and prognosis of cervical cancer. PET-CT can accurately locate the anatomical sites of tracer uptake and improve the diagnostic accuraccy of PET. (authors)

The petit rat (pet/pet), a new semilethal mutant dwarf rat with thymic and testicular anomalies.

Science.gov (United States)

Chiba, Junko; Suzuki, Katsushi; Suzuki, Hiroetsu

2008-12-01

The petit rat (pet/pet) is a recently discovered semilethal mutant dwarf. The neonatal pet/pet rats had a low body weight and small thymus and testis. During the first 3 d after birth, 50% of the male and 80% of the female pet/pet pups were lost or found dead. Surviving pet/pet rats showed marked retardation of postnatal growth, and their body weights were 41% (female rats) and 32% (male rats) of those of normal rats at the adult stage. The pet/pet rats exhibited proportional dwarfism, and their longitudinal bones were shorter than those of controls without skeletal malformations. Most organs of male pet/pet rats, especially the thymus, testis, adipose tissue surrounding the kidney, and accessory sex organs, weighed markedly less at 140 d of age than did those of their normal counterparts. The thymus of pet/pet rats was small with abnormal thymic follicles. Testes from pet/pet rats exhibited 2 patterns of abnormal histology. Spermatogenesis was present in testes that were only slightly anomalous, but the seminiferous tubules were reduced in diameter. In severely affected testes, most of the seminiferous tubules showed degeneration, and interstitial tissue was increased. Plasma growth hormone concentrations did not differ between pet/pet and normal male rats. The dwarf phenotype of pet/pet rats was inherited as an autosomal recessive trait. These results indicate that the pet/pet rat has a semilethal growth-hormone-independent dwarf phenotype that is accompanied by thymic and testicular anomalies and low birth weight.

Value of PET and PET-CT for monitoring tumor therapy

International Nuclear Information System (INIS)

Chen Xiang; Zhao Jinhua

2007-01-01

18 F-fluorodeoxyglucose ( 18 F-FDG) PET or PET-CT is an accurate test for differentiating residual viable tumor tissue from therapy-induced changes in tumor. Furthermore, quantitative assessment of therapy-induced changes in tumor 18 F-FDG uptake may allow the prediction of tumor response. Treatment may be adjusted according to tumor response. So it is increasingly used to monitor tumor response in patients undergoing chemotherapy and chemoradiotherapy. Here we focused on practical aspects of 18 F-FDG PET or PET-CT for treatment monitoring and on the existing advantages and challenges. (authors)

Differentiation of molecular chain entanglement structure through laser Raman spectrum measurement of High strength PET fibers under stress

Science.gov (United States)

Go, D.; Takarada, W.; Kikutani, T.

2017-10-01

The aim of this study was to investigate the mechanism for the improvement of mechanical properties of poly(ethylene terephthalate) (PET) fibers based on the concept of controlling the state of molecular entanglement. For this purpose, five different PET fibers were prepared through either the conventional melt spinning and drawing/annealing process or the high-speed melt spinning process. In both cases, the melt spinning process was designed so as to realize different Deborah number conditions. The prepared fibers were subjected to the laser Raman spectroscopy measurement and the characteristics of the scattering peak at around 1616 cm-1, which corresponds to the C-C/C=C stretching mode of the aromatic ring in the main chain, were investigated in detail. It was revealed that the fibers drawn and annealed after the melt spinning process of lower Deborah number showed higher tensile strength as well as lower value of full width at half maximum (FWHM) in the laser Raman spectrum. Narrow FWHM was considered to represent the homogeneous state of entanglement structure, which may lead to the higher strength and toughness of fibers because individual molecular chains tend to bare similar level of tensile stress when the fiber is stretched. In case of high-speed spun fibers prepared with a high Deborah number condition, the FWHM was narrow presumably because much lower tensile stress in comparison with the drawing/annealing process was applied when the fiber structure was developed, however the value increased significantly upon applying tensile load to the fibers during the laser Raman spectrum measurement. From these results, it was concluded that the Laser Raman spectroscopy could differentiate molecular chain entanglement structure of various fiber samples, in that low FWHM, which corresponds to either homogeneous state of molecular entanglement or lower level of mean residual stress, and small increase of FWTH upon applying tensile stress are considered to be the key

PetIGA-MF: a multi-field high-performance toolbox for structure-preserving B-splines spaces

KAUST Repository

Sarmiento, Adel

2016-10-01

We describe a high-performance solution framework for isogeometric discrete differential forms based on B-splines: PetIGA-MF. Built on top of PetIGA, an open-source library we have built and developed over the last decade, PetIGA-MF is a general multi-field discretization tool. To test the capabilities of our implementation, we solve different viscous flow problems such as Darcy, Stokes, Brinkman, and Navier-Stokes equations. Several convergence benchmarks based on manufactured solutions are presented assuring optimal convergence rates of the approximations, showing the accuracy and robustness of our solver.

Processing and characterization of extruded PET and its r-PET and ...

Indian Academy of Sciences (India)

of r-PET and r-PET+ MWCNT fillers was obtained by the precipitation method using TFA as a solvent and acetone ... crystallinity in r-PET and decrease in chain entanglements. ..... insufficient to supply the complete information of the surface.

PET image reconstruction with rotationally symmetric polygonal pixel grid based highly compressible system matrix

International Nuclear Information System (INIS)

Yu Yunhan; Xia Yan; Liu Yaqiang; Wang Shi; Ma Tianyu; Chen Jing; Hong Baoyu

2013-01-01

To achieve a maximum compression of system matrix in positron emission tomography (PET) image reconstruction, we proposed a polygonal image pixel division strategy in accordance with rotationally symmetric PET geometry. Geometrical definition and indexing rule for polygonal pixels were established. Image conversion from polygonal pixel structure to conventional rectangular pixel structure was implemented using a conversion matrix. A set of test images were analytically defined in polygonal pixel structure, converted to conventional rectangular pixel based images, and correctly displayed which verified the correctness of the image definition, conversion description and conversion of polygonal pixel structure. A compressed system matrix for PET image recon was generated by tap model and tested by forward-projecting three different distributions of radioactive sources to the sinogram domain and comparing them with theoretical predictions. On a practical small animal PET scanner, a compress ratio of 12.6:1 of the system matrix size was achieved with the polygonal pixel structure, comparing with the conventional rectangular pixel based tap-mode one. OS-EM iterative image reconstruction algorithms with the polygonal and conventional Cartesian pixel grid were developed. A hot rod phantom was detected and reconstructed based on these two grids with reasonable time cost. Image resolution of reconstructed images was both 1.35 mm. We conclude that it is feasible to reconstruct and display images in a polygonal image pixel structure based on a compressed system matrix in PET image reconstruction. (authors)

How PET is changing the management of cancer with radiotherapy

International Nuclear Information System (INIS)

Mac Manus, M.

2005-01-01

Information from PET scanning is transforming the management of many malignancies and the impact of PET is likely to increase further as new indications are recognised. PET is of particular value in patients treated with radiotherapy (RT) with curative intent. These patients rarely undergo invasive surgical staging and therefore imaging is crucial in determining the extent of disease before treatment. More accurate staging with PET means that futile aggressive RT or chcmoRT can be avoided in patients with incurable extensive disease. FDG-PET is of proven value in the staging of common metabolically-active malignancies treated with radiotherapy. These include lung cancer, head and neck cancer, lymphomas and oesophageal carcinoma. It has been shown that PET can improve the selection of patients for radical surgery or radiotherapy in lung cancer and that PET-based staging more accurately predicts survival than conventional staging. For those patients that remain eligible for definitive RT after PET. treatment can be more accurately targeted at the tumour and involved regional nodes. The value of PET for treatment planning is enhanced significantly when PET and CT scans are acquired on a combined PET/CT scanner. Fused PET-CT images can be imported into the radiotherapy planning computer and used to accurately target tumour with the best beam arrangement. After treatment, response may be hard to assess with structural imaging. PET-rcsponse to chemotherapy or radiotherapy in non-small cell lung cancer (NSCLC) predicts survival in NSCLC more accurately than CT response. However, PET has much more potential than imaging with FDG alone can realise. Markers such as FLT can be used to image proliferation in tumours, misonidazole or FAZA can be used to image hypoxia and labeled metabolites of anti-cancer drugs such as 5-FU can be used to study pharmacokinetics. New combinations of radiation and drugs may emerge that can be selected based on biological characteristics of

Attenuation correction for brain PET imaging using deep neural network based on dixon and ZTE MR images.

Science.gov (United States)

Gong, Kuang; Yang, Jaewon; Kim, Kyungsang; El Fakhri, Georges; Seo, Youngho; Li, Quanzheng

2018-05-23

Positron Emission Tomography (PET) is a functional imaging modality widely used in neuroscience studies. To obtain meaningful quantitative results from PET images, attenuation correction is necessary during image reconstruction. For PET/MR hybrid systems, PET attenuation is challenging as Magnetic Resonance (MR) images do not reflect attenuation coefficients directly. To address this issue, we present deep neural network methods to derive the continuous attenuation coefficients for brain PET imaging from MR images. With only Dixon MR images as the network input, the existing U-net structure was adopted and analysis using forty patient data sets shows it is superior than other Dixon based methods. When both Dixon and zero echo time (ZTE) images are available, we have proposed a modified U-net structure, named GroupU-net, to efficiently make use of both Dixon and ZTE information through group convolution modules when the network goes deeper. Quantitative analysis based on fourteen real patient data sets demonstrates that both network approaches can perform better than the standard methods, and the proposed network structure can further reduce the PET quantification error compared to the U-net structure. © 2018 Institute of Physics and Engineering in Medicine.

Clinical Application of 18F-FDG PET in Epilepsy

International Nuclear Information System (INIS)

Kim, Yu Kyeong

2008-01-01

FDG PET has been used as a diagnostic tool for localization of seizure focus for last 2-3 decades. In this article, the clinical usefulness of FDG PET in the management of patients with epilepsy has been reviewed, which provided the evidences to justify the medicare reimbursement for FDG PET in management of patients with epilepsy. Literature review demonstrated that FDG PET provides an important information in localization of seizure focus and determination whether a patients is a surgical candidate or not. FDG PET has been reported to have high diagnostic performance in localization of seizure focus in neocortical epilepsy as well as temporal lobe epilepsy regardless of the presence of structural lesion on MRI. Particularly, FDG PET can provide the additional information when the results from standard diagnositic modality such as interictal or video-monitored EEG, and MRI are inconclusive or discordant, and make to avoid invasive study. Furthermore, the presence of hypometabolism and extent of metabolic extent has been reported as an important predictor for seizure free outcome. However, studies suggested that more accurate localization and better surgical outcome could be expected with multimodal approach by combination of EEG, MRI, and functional studies using FDG PET or perfusion SPECT rather than using a single diagnostic modality in management of patients with epilepsy. Complementary use of FDG PET in management of epilepsy is worth for good surgical outcome in epilepsy patients

PET and PET/CT in tumour of undetermined origin

International Nuclear Information System (INIS)

Garcia O, J.R.

2007-01-01

In this presentation the following conclusions were obtained regarding the use of PET and PET/CT in patient with cancer of unknown primary: 1. Detection of the primary one in 1/3 at 1/2 of patient. 2. It detects metastases in other places in 50%. 3. It changes the initial therapy planned in 1/3 at 1/2 of patient. 4. Useful in initial phases of protocol study to limit the other procedures. After standard evaluation. Before advanced protocol. 5. PET/CT study increases the % of primary detection, although in a non significant way vs. PET. 6. They are required more studies to value their utility to a more objective manner. (Author)

Clinical applications of PET/CT

International Nuclear Information System (INIS)

Le Ngoc Ha

2011-01-01

The purpose of this article is to review the evolution of PET, PET/CT focusing on the technical aspects, PET radiopharmaceutical developments and current clinical applications as well. The newest technologic advances have been reviewed, including improved crystal design, acquisition modes, reconstruction algorithms, etc. These advancements will continue to improve contrast, decrease noise, and increase resolution. Combined PET/CT system provides faster attenuation correction and useful anatomic correlation to PET functional information. A number of new radiopharmaceuticals used for PET imaging have been developed, however, FDG have been considered as the principal PET radiotracer. The current clinical applications of PET and PET/CT are widespread and include oncology, cardiology and neurology. (author)

A Trajectory Correction based on Multi-Step Lining-up for the CLIC Main Linac

CERN Document Server

D'Amico, T E

1999-01-01

In the CLIC main linac it is very important to minimise the trajectory excursion and consequently the emittance dilution in order to obtain the required luminosity. Several algorithms have been proposed and lately the ballistic method has proved to be very effective. The trajectory method described in this Note retains the main advantages of the latter while adding some interesting features. It is based on the separation of the unknown variables like the quadrupole misalignments, the offset and slope of the injection straight line and the misalignments of the beam position monitors (BPM). This is achieved by referring the trajectory relatively to the injection line and not to the average pre-alignment line and by using two trajectories each corresponding to slightly different quadrupole strengths. A reference straight line is then derived onto which the beam is bent by a kick obtained by moving the first quadrupole. The other quadrupoles are then aligned on that line. The quality of the correction depends mai...

Revolutionary impact of PET and PET-CT on the day-to-day practice of medicine and its great potential for improving future health care

International Nuclear Information System (INIS)

Basu, S.; Alavi, A.

2009-01-01

In this communication, we present an overview of the impact and advantages of PET and PET-CT fusion imaging in the practice of medicine. We also discuss the evolution of this promising molecular imaging technique since its inception and the future prospects of the combined structure-function approach. Superior contrast resolution, accurate quantification and above all optimal image quality aid in improved diagnosis of many serious disorders including cancer. We speculate that this powerful imaging approach will almost completely replace most other conventional methods in the future. Currently, 18[F]-fluorodeoxyglucose (FDG) is the main radiopharmaceutical employed for PET studies around the globe. With the availability of high quality PET images on a routine basis in most centres around the world and the likelihood that several other useful PET tracers will be approved in the near future for routine clinical applications, this technique will likely become essential in almost any medical disorder. (authors)

Diagnosis and dosimetry in differentiated thyroid carcinoma using 124I PET: comparison of PET/MRI vs PET/CT of the neck

International Nuclear Information System (INIS)

Nagarajah, James; Jentzen, Walter; Hartung, Verena; Rosenbaum-Krumme, Sandra; Bockisch, Andreas; Stahl, Alexander; Mikat, Christian; Heusner, Till Alexander; Antoch, Gerald

2011-01-01

This study compares intrinsically coregistered 124 I positron emission tomography (PET) and CT (PET/CT) and software coregistered 124 I PET and MRI (PET/MRI) images for the diagnosis and dosimetry of thyroid remnant tissues and lymph node metastases in patients with differentiated thyroid carcinoma (DTC). After thyroidectomy, 33 high-risk DTC patients (stage III or higher) received 124 I PET/CT dosimetry prior to radioiodine therapy to estimate the absorbed dose to lesions and subsequently underwent a contrast-enhanced MRI examination of the neck. Images were evaluated by two experienced nuclear medicine physicians and two radiologists to identify the lesions and to categorize their presumable provenience, i.e. thyroid remnant tissue (TT), lymph node metastasis (LN) and inconclusive tissue. The categorization and dosimetry of lesions was initially performed with PET images alone (PET only). Subsequently lesions were reassessed including the CT and MRI data. The analyses were performed on a patient and on a lesion basis. Patient-based analyses showed that 26 of 33 (79%) patients had at least one lesion categorized as TT on PET only. Of these patients, 11 (42%) and 16 (62%) had a morphological correlate on CT and MRI, respectively, in at least one TT PET lesion. Twelve patients (36%) had at least one lesion classified as LN on PET only. Nine (75%) of these patients had a morphological correlate on both CT and MRI in at least one LN PET lesion. Ten patients (30%) showed at least one lesion on PET only classified as inconclusive. The classification was changed to a clear classification in two patients (two LN) by CT and in four (two TT, two LN) patients by MRI. Lesion-based analyses (n = 105 PET positive lesions) resulted in categorization as TT in 61 cases (58%), 16 (26%) of which had a morphological correlate on CT and 33 (54%) on MRI. A total of 29 lesions (27%) were classified as LN on PET, 18 (62%) of which had a morphological correlate on CT and 24 (83%) on MRI

Clinical Application of F-18 FDG PET (PET/CT) in Colo-rectal and Anal Cancer

International Nuclear Information System (INIS)

Kim, Byung Il

2008-01-01

In the management of colo-retal and anal cancer, accurate staging, treatment evaluation, early detection of recurrence are main clinical problems. F-18 FDG PET (PET/CT) has been reported as useful in the management of colo-rectal and anal cancer because that PET has high diagnostic performance comparing to conventional studies. In case of liver metastases, for confirmation of no extrahepatic metastases, in case of high risk of metastasis, for avoiding unnecessary operation, PET (PET/CT) is expected more useful. In anal cancer, PET is expected useful in lymph node staging. For the early prediction of chemotherapy or radiation therapy effect PET has been reported as useful, also. In early detection of recurrence by PET, cost-benefit advantages has been suggested, also. PET/CT is expected to have higher diagnostic performance than PET alone

Clinical Application of F-18 FDG PET (PET/CT) in Malignancy of Unknown Origin

International Nuclear Information System (INIS)

Kim, Byung Il

2008-01-01

Diagnosis of primary origin site in the management of malignancy of unknown origin (MUO) is the most important issue. According to the histopathologic subtype of primary lesion, specialized treatment can be given and survival gain is expected. F-18 FDG PET (PET/CT) has been estimated as useful in detection of primary lesion with high sensitivity and moderate specificity. F-18 FDG PET (PET/CT) study before conventional studies is also recommended because it has high diagnostic performance compared to conventional studies. Although there has few data, F-18 FDG PET (PET/CT) is expected to be useful in diagnosis of recurrence, restaging, evaluation of treatment effect, considering that PET (PET/CT) has been reported as useful in other malignancies

Basic study of entire whole-body PET scanners based on the OpenPET geometry

Energy Technology Data Exchange (ETDEWEB)

Yoshida, Eiji, E-mail: rush@nirs.go.j [National Institute of Radiological Sciences, 4-9-1 Inage-ku, Chiba 263-8555 (Japan); Yamaya, Taiga; Nishikido, Fumihiko; Inadama, Naoko; Murayama, Hideo [National Institute of Radiological Sciences, 4-9-1 Inage-ku, Chiba 263-8555 (Japan)

2010-09-21

A conventional PET scanner has a 15-25 cm axial field-of-view (FOV) and images a whole body using about six bed positions. An OpenPET geometry can extend the axial FOV with a limited number of detectors. The entire whole-body PET scanner must be able to process a large amount of data effectively. In this work, we study feasibility of the fully 3D entire whole-body PET scanner using the GATE simulation. The OpenPET has 12 block detector rings with the ring diameter of 840 mm and each block detector ring consists of 48 depth-of-interaction (DOI) detectors. The OpenPET has the axial length of 895.95 mm with five parts of 58.95 mm open gaps. The OpenPET has higher single data loss than a conventional PET scanner at grouping circuits. NECR of the OpenPET decreases by single data loss. But single data loss is mitigated by separating the axially arranged detector into two parts. Also, multiple coincidences are found to be important for the entire whole-body PET scanner. The entire whole-body PET scanner with the OpenPET geometry promises to provide a large axial FOV with the open space and to have sufficient performance values. But single data loss at the grouping circuits and multiple coincidences are limited to the peak noise equivalent count rate (NECR) for the entire whole-body PET scanner.