Performance of Large Area Micromegas Detectors for the ATLAS Muon Spectrometer Upgrade Project

CERN Document Server

AUTHOR|(SzGeCERN)743338; The ATLAS collaboration

2016-01-01

Four German institutes are building 32 high-rate capable SM2 Micromegas quadruplets, for the upgrade of the Small Wheels of the ATLAS muon spectrometer. The cathodes and strip-anodes of the 2 m$^2$ quadruplets consist of stable honeycomb sandwiches with a requested planarity better than 80 $\\mu$m. The qualification of full-size SM2 quadruplets will be performed in the Munich Cosmic Ray Measurement Facility (CRMF). Two fully working 4 m $\\times$ 2.2 m ATLAS drift-tube chambers provide muon tracking, a RD51 SRS based data acquisition system provides readout of all 12288 electronic channels using 96 APV25 front-end boards. The goal is to measure the homogeneity of pulse-height and efficiency and to determine the planarity of the sandwich planes and the positions of the readout-strips. This has been pioneered by studying a 102 $\\times$ 92 cm$^2$ Micromegas chamber with similar readout pitch in the CRMF using the TPC-like analysis method. At trigger rates above 100 Hz data taking takes only a few days for sufficie...

Performance of Large Area Micromegas Detectors for the ATLAS Muon Spectrometer Upgrade Project

CERN Document Server

Losel, Philipp Jonathan; The ATLAS collaboration; Hertenberger, Ralf; Mueller, Ralph Soeren Peter; Bortfeldt, Jonathan; Flierl, Bernhard Matthias; Zibell, Andre

2016-01-01

Four German institutes are building the 32 high-rate capable SM2 Micromegas quadruplets, for the upgrade of the Small Wheels of the ATLAS muon spectrometer. The cathodes and strip-anodes of the m$^2$ in size quadruplets consist of stable honeycomb sandwiches with a requested planarity better than 80 $\\mu$m. The qualification of a full-size SM2 quadruplet, foreseen by ATLAS time schedule for August 2015, will be performed in the Munich Cosmic Ray Measurement Facility (CRMF). Two fully working 4 m$\\times$ 2.2 m ATLAS drift-tube chambers provide muon tracking, a RD51 SRS based data acquisition system provides readout of all 12288 electronic channels using 96 APV25 frontend boards. We report on homogeneity of pulse-height and efficiency and will present measurements of the planarity of the sandwich planes and the positions of the readout-strips. This has been pioneered by studying a $102 \\times 92$ cm$^2$ Micromegas chamber with similar readout pitch in the CRMF using the TPC-like analysis method. At trigger rate...

Development of a high rate TPC. The ALICE TPC upgrade after LS2

Energy Technology Data Exchange (ETDEWEB)

Ball, Markus [Rheinische Friedrich-Wilhelms-Universitaet Bonn (Germany); Collaboration: ALICE-Collaboration

2016-07-01

The ALICE (A Large Ion Collider Experiment at CERN) collaboration plans an upgrade of the detector system during the second long shutdown of the LHC, during which the interaction rate will be increased to 50 kHz for Pb-Pb collisions. This demands operation of the Time Projection Chamber (TPC) in an ungated continuous mode. A conventional gating grid can not be used to prevent ions drifting back into the drift volume. Micro Pattern Gaseous Detectors (MPGD) such as GEMs and Micromegas offer suppression of the ion backflow. To keep distortions due to space-charge at a tolerable level an ion yield of 10 to 20 back drifting ions per incoming electron is required. However, the need for low ion backflow might be in conflict to other key parameters such as the detector performance and stability of the system. Therefore a careful optimisation of all three requirements was needed. Furthermore the large scale capability of the system has to be guaranteed. Test beams have been carried out to study the large scale performance with an Inner Readout Chamber (IROC) equipped with a multiple GEM system. Also an quadruple GEM Outer Readout Chamber (OROC) was assembled and successfully operated being the largest detector of this type. The upgrade of all readout chambers with a quadruple GEM system has started in 2016. The strategy and the work flow of the TPC upgrade are presented.

The data acquisition of the Micromegas detector for the CAST experiment

CERN Document Server

Geralis, T; Giomataris, Ioanis; Zachariadou, K

2004-01-01

The Micromegas ( mu M) detector is one of the three types of detectors (CCD, mu M and TPC) that are used for solar axion detection at the CAST experiment. The mu M detector is sensitive to X-rays, originating from a conversion of axion to photon in a strong magnetic field (9T), in the range of a few hundred eV to 10 keV. Good detection efficiency, energy resolution, spatial resolution and extremely low background are the characteristics of this type of detector. The Data Acquisition of the Micromegas detector is presented here. The Front End cards are using multiplexed analog integrated circuits. A set of VME modules performs the readout that is expandable to read up to 2 * 19 * 2048 (77824) channels. The system has the capability to apply online, per individual channel, a threshold and a subsequent pedestal subtraction. At the CAST experiment rates the dead time is negligible. A PCI-MXI2-VME interface is used to read out the data to a PC, to perform monitoring and to Display Events. The system is based on th...

Study of the performance of Micromegas detectors in magnetic field

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00222923; The ATLAS collaboration

2015-01-01

Resistive Micromegas (MICRO MEsh GAseous Structure) detectors have been chosen by the ATLAS collaboration at LHC for the high luminosity upgrade, due to their capability to maintain full efficiency and high spatial resolution at high occupancy, for tracking muons in the forward region of the detector. The Inner Muon Station, in the high-rapidity region, the so called New Small Wheel (NSW), will be composed of micromegas detectors that will have to maintain good performance in the presence of magnetic field of up to about 0.3 T. The response of micromegas detectors is affected by the magnetic field, where the deflection of the drift electrons is described by the Lorentz angle, resulting in a bias in the reconstructed track position. Several test-beam campaigns have been performed to test the behaviour of small size resistive micromegas prototypes ($10 \\times 10 \\text{cm}^2$) in magnetic fields up to 1 T, using high momentum muon and hadron beams at CERN. These studies are performed in order to validate the cap...

Study of the performance of Micromegas detectors in magnetic field

Directory of Open Access Journals (Sweden)

Dimitrios Sampsonidis

2018-01-01

Full Text Available Resistive Micromegas (MICRO MEsh GAseous Structure detectors have been chosen by the ATLAS collaboration at LHC for the high luminosity upgrade, due to their capability to maintain full efficiency and high spatial resolution at high occupancy, for tracking muons in the forward region of the detector. The Inner Muon Station, in the high-rapidity region, the so called New Small Wheel (NSW, will be composed of micromegas detectors that will have to maintain good performance in the presence of magnetic field of up to about 0.3 T. The response of micromegas detectors is affected by the magnetic field, where the deflection of the drift electrons is described by the Lorentz angle, resulting in a bias in the reconstructed track position. Several test-beam campaigns have been performed to test the behaviour of small size resistive micromegas prototypes (10×10 cm2 in magnetic fields up to 1 T, using high momentum muon and hadron beams at CERN. These studies are performed in order to validate the capability of the chambers to provide unbiased tracks in the NSW conditions. Measurements of the Lorentz angle and drift velocity as a function of the magnetic field are presented and both are compared to expectations based on Garfield-Magboltz simulations. Several methods to correct the position bias are applied, based on the chamber configuration or on the knowledge of the local value of the magnetic field. The results of these studies are presented together with an overall discussion of the Micromegas tracking capability in magnetic field.

Study of the performance of Micromegas detectors in magnetic field

Science.gov (United States)

Dimitrios, Sampsonidis

2018-02-01

Resistive Micromegas (MICRO MEsh GAseous Structure) detectors have been chosen by the ATLAS collaboration at LHC for the high luminosity upgrade, due to their capability to maintain full efficiency and high spatial resolution at high occupancy, for tracking muons in the forward region of the detector. The Inner Muon Station, in the high-rapidity region, the so called New Small Wheel (NSW), will be composed of micromegas detectors that will have to maintain good performance in the presence of magnetic field of up to about 0.3 T. The response of micromegas detectors is affected by the magnetic field, where the deflection of the drift electrons is described by the Lorentz angle, resulting in a bias in the reconstructed track position. Several test-beam campaigns have been performed to test the behaviour of small size resistive micromegas prototypes (10×10 cm2) in magnetic fields up to 1 T, using high momentum muon and hadron beams at CERN. These studies are performed in order to validate the capability of the chambers to provide unbiased tracks in the NSW conditions. Measurements of the Lorentz angle and drift velocity as a function of the magnetic field are presented and both are compared to expectations based on Garfield-Magboltz simulations. Several methods to correct the position bias are applied, based on the chamber configuration or on the knowledge of the local value of the magnetic field. The results of these studies are presented together with an overall discussion of the Micromegas tracking capability in magnetic field.

Metal-core pad-plane development for ACTAR TPC

Science.gov (United States)

Giovinazzo, J.; Pibernat, J.; Goigoux, T.; de Oliveira, R.; Grinyer, G. F.; Huss, C.; Mauss, B.; Pancin, J.; Pedroza, J. L.; Rebii, A.; Roger, T.; Rosier, P.; Saillant, F.; Wittwer, G.

2018-06-01

With the recent development of active targets and time projection chambers (ACTAR TPC) as detectors for fundamental nuclear physics experiments, the need arose for charge collection planes with a high density of readout channels. In order to fulfill the mechanical constraints for the ACTAR TPC device, we designed a pad-plane based on a metal-core circuit with an conceptually simple design and routing for signal readout, named FAKIR (in reference to a fakir bed of nails). A test circuit has been equipped with a micro mesh gaseous structure (micromegas) for signal amplification and a dedicated readout electronics. Test measurements have been performed with an 55Fe X-ray source giving an intrinsic energy resolution (FWHM) of 22 ± 1% at 5 . 9 keV, and with a 3-alpha source for which a resolution of about 130 ± 20 keV at 4 . 8 MeV has been estimated. The pad-plane has been mounted into a reduced size demonstrator version of the ACTAR TPC detector, in order to illustrate charged particle track reconstruction. The tests preformed with the X-ray and the 3-alpha sources shows that results obtained from pads signals are comparable to the intrinsic result from the micro-mesh signal. In addition, a simple alpha particle tracks analysis is performed to demonstrate that the pad plane allows a precise reconstruction of the direction and length of the trajectories.

Performance Studies of Micromegas Chambers for the New Small Wheel Upgrade Project

Directory of Open Access Journals (Sweden)

Leontsinis S.

2016-01-01

Full Text Available The ATLAS collaboration has chosen the Micromegas technology along with the small-strip Thin Gap Chambers for the upgrade of the inner muon station in the high-rapidity region, the so called New Small Wheel upgrade project. It will employ eight layers of Micromegas and eight layers of small-strip Thin Gap Chambers per wheel. The New Small Wheel project requires fully efficient Micromegas chambers, able to cope with the maximum expected rate of 15 kHz/cm2 featuring single plane spatial resolution better than 100 μm. The Micromegas detectors will cover a total active area of ~ 1200 m2 and will be operated in a moderate magnetic field (≤ 0.3 T. Moreover, together with their precise tracking capability the New Small Wheel Micromegas chambers will contribute to the ATLAS Level-1 trigger system. Several studies have been performed on small (10 × 10 cm2 and medium (1 × 0.5 m2 size prototypes using medium (1 − 5 GeV/c and high momentum (120 – 150 GeV/c hadron beams at CERN. A brief overview of the results obtained is presented.

Recent advances with a hybrid micro-pattern gas detector operated in low pressure H2 and He, for AT-TPC applications

Directory of Open Access Journals (Sweden)

Cortesi Marco

2018-01-01

Full Text Available In view of a possible application as a charge-particle track readout for an Active-Target Time Projection Chamber (AT-TPC, the operational properties and performances of a hybrid Micro-Pattern Gaseous Detector (MPGD were investigated in pure low-pressure Hydrogen (H2 and Helium (He. The detector consists of a MICROMEsh GAseous Structure (MICROMEGAS coupled to a two-cascade THick Gaseous Electron Multiplier (THGEM as a pre-amplification stage. This study reports the effective gain dependence of the hybrid-MPGD at relevant pressure (in the range of 200-760 torr for different detector arrangements. The results of this work are relevant in the field of avalanche mechanism in low-pressure, low-mass noble gases, in particularly for applications of MPGD end-cap readout for active-target Time Projection Chambers (TPC in the field of nuclear physics and nuclear astrophysics.

CAST with its micromegas detector installed.

CERN Multimedia

Maximilien Brice

2002-01-01

The CERN Axion Solar Telescope (CAST) uses a prototype LHC dipole magnet to search for very weakly interacting neutral particles called axions, which should originate in the core of the Sun. The magnet converts the solar axions to photons which are then detected by an X-ray detector based on Micromegas technology. CAST's Micromegas detector has now been installed. Photos 01 02: General view of the CAST experiment with the Micromegas detector in place. Photo 03: Close-up of the micromegas set-up.

Development of floating strip micromegas detectors

Energy Technology Data Exchange (ETDEWEB)

Bortfeldt, Jonathan

2014-04-28

Micromegas are high-rate capable, high-resolution micro-pattern gaseous detectors. Square meter sized resistive strip Micromegas are foreseen as replacement of the currently used precision tracking detectors in the Small Wheel, which is part of the forward region of the ATLAS muon spectrometer. The replacement is necessary to ensure tracking and triggering performance of the muon spectrometer after the luminosity increase of the Large Hadron Collider beyond its design value of 10{sup 34} cm{sup -2}s{sup -1} around 2020. In this thesis a novel discharge tolerant floating strip Micromegas detector is presented and described. By individually powering copper anode strips, the effects of a discharge are confined to a small region of the detector. This reduces the impact of discharges on the efficiency by three orders of magnitude, compared to a standard Micromegas. The physics of the detector is studied and discussed in detail. Several detectors are developed: A 6.4 x 6.4 cm{sup 2} floating strip Micromegas with exchangeable SMD capacitors and resistors allows for an optimization of the floating strip principle. The discharge behavior is investigated on this device in depth. The microscopic structure of discharges is quantitatively explained by a detailed detector simulation. A 48 x 50 cm{sup 2} floating strip Micromegas is studied in high energy pion beams. Its homogeneity with respect to pulse height, efficiency and spatial resolution is investigated. The good performance in high-rate background environments is demonstrated in cosmic muon tracking measurements with a 6.4 x 6.4 cm{sup 2} floating strip Micromegas under lateral irradiation with 550 kHz 20 MeV proton beams. A floating strip Micromegas doublet with low material budget is developed for ion tracking without limitations from multiple scattering in imaging applications during medical ion therapy. Highly efficient tracking of 20 MeV protons at particle rates of 550 kHz is possible. The reconstruction of the

Development of floating strip micromegas detectors

International Nuclear Information System (INIS)

Bortfeldt, Jonathan

2014-01-01

Micromegas are high-rate capable, high-resolution micro-pattern gaseous detectors. Square meter sized resistive strip Micromegas are foreseen as replacement of the currently used precision tracking detectors in the Small Wheel, which is part of the forward region of the ATLAS muon spectrometer. The replacement is necessary to ensure tracking and triggering performance of the muon spectrometer after the luminosity increase of the Large Hadron Collider beyond its design value of 10 34 cm -2 s -1 around 2020. In this thesis a novel discharge tolerant floating strip Micromegas detector is presented and described. By individually powering copper anode strips, the effects of a discharge are confined to a small region of the detector. This reduces the impact of discharges on the efficiency by three orders of magnitude, compared to a standard Micromegas. The physics of the detector is studied and discussed in detail. Several detectors are developed: A 6.4 x 6.4 cm 2 floating strip Micromegas with exchangeable SMD capacitors and resistors allows for an optimization of the floating strip principle. The discharge behavior is investigated on this device in depth. The microscopic structure of discharges is quantitatively explained by a detailed detector simulation. A 48 x 50 cm 2 floating strip Micromegas is studied in high energy pion beams. Its homogeneity with respect to pulse height, efficiency and spatial resolution is investigated. The good performance in high-rate background environments is demonstrated in cosmic muon tracking measurements with a 6.4 x 6.4 cm 2 floating strip Micromegas under lateral irradiation with 550 kHz 20 MeV proton beams. A floating strip Micromegas doublet with low material budget is developed for ion tracking without limitations from multiple scattering in imaging applications during medical ion therapy. Highly efficient tracking of 20 MeV protons at particle rates of 550 kHz is possible. The reconstruction of the track inclination in a single

Study of the performance of Micromegas detectors in magnetic field

CERN Document Server

Sampsonidis, Dimos; The ATLAS collaboration

2016-01-01

Resistive Micromegas (Micro MEsh Gaseous Structure) detectors have been chosen by the ATLAS collaboration at LHC for the high luminosity upgrade due to their capability to maintain full efficiency and high spatial resolution at high rates. Operation in the Inner Muon Station of the high-rapidity region, the so called New Small Wheel (NSW) requires also these performances to be maintened in magnetic fields up to about 0.3 T. The response of Micromegas chambers is affected by the magnetic field where the deflection of the drift electrons is described by the Lorentz angle, resulting in a bias in the reconstructed position. Several test-beam campaigns have been performed to test the behaviour of small size resistive micromegas prototypes (10x10cm2) in magnetic fields up to 1 T using high momentum muon and hadron beams at CERN. These studies are performed in order to validate the capability to operate these chambers to get unbiased tracks in the NSW conditions. Measurements of the Lorentz angle and drift velocity ...

TPC workshop summary

International Nuclear Information System (INIS)

Nygren, D.R.

1984-01-01

The Time Projection Chamber (TPC) concept is now nearly ten years old and, as is evident in this workshop, is still evolving in many directions. From the liquid xenon TPC for double beta decay studies to the impressively large second generation TPC for the LEP experiment ALEPH, the surprising diversity of current applications is apparent. This workshop, the first to concentrate solely on the TPC has provided a most congenial and rewarding occasion for all TPC enthusiasts to share experience, results, and ideas

Performances of Anode-resistive Micromegas for HL-LHC

CERN Document Server

Manjarres, J.; Attié, D.; Boyer, M.; Derré, J.; Fanourakis, G.; Ferrer-Ribas, E.; Galán, J.; Gazis, E.; Geralis, T.; Giganon, A.; Giomataris, I.; Herlant, S.; Jeanneau, F.; Schune, Ph.; Titov, M.; Tsipolitis, G.

2012-03-20

Micromegas technology is a promising candidate to replace Atlas forward muon chambers -tracking and trigger- for future HL-LHC upgrade of the experiment. The increase on background and pile-up event probability requires detector performances which are currently under studies in intensive RD activities. We studied performances of four different resistive Micromegas detectors with different read-out strip pitches. These chambers were tested using \\sim120 GeV momentum pions, at H6 CERN-SPS beam line in autumn 2010. For a strip pitch 500 micrometers we measure a resolution of \\sim90 micrometers and a efficiency of ~98%. The track angle effect on the efficiency was also studied. Our results show that resistive techniques induce no degradation on the efficiency or resolution, with respect to the standard Micromegas. In some configuration the resistive coating is able to reduce the discharge currents at least by a factor of 100.Micromegas technology is a promising candidate to replace Atlas forward muon chambers -tr...

Development of Resistive Micromegas for Sampling Calorimetry

Science.gov (United States)

Geralis, T.; Fanourakis, G.; Kalamaris, A.; Nikas, D.; Psallidas, A.; Chefdeville, M.; Karyotakis, I.; Koletsou, I.; Titov, M.

2018-02-01

Resistive micromegas is proposed as an active element for sampling calorimetry. Future linear collider experiments or the HL-LHC experiments can profit from those developments for Particle Flow Calorimetry. Micromegas possesses remarkable properties concerning gain stability, reduced ion feedback, response linearity, adaptable sensitive element granularity, fast response and high rate capability. Recent developments on Micromegas with a protective resistive layer present excellent results, resolving the problem of discharges caused by local high charge deposition, thanks to its RC-slowed charge evacuation. Higher resistivity though, may cause loss of the response linearity at high rates. We have scanned a wide range of resistivities and performed laboratory tests with X-rays that demonstrate excellent response linearity up to rates of (a few) times 10MHz/cm2, with simultaneous mitigation of discharges. Beam test studies at SPS/CERN with hadrons have also shown a remarkable stability of the resistive Micromegas and low currents for rates up to 15MHz/cm2. We present results from the aforementioned studies confronted with MC simulation

First considerations for a readout system for the ILD TPC with the Timepix3

Energy Technology Data Exchange (ETDEWEB)

Schiffer, Tobias [Universitaet Bonn (Germany); Collaboration: LCTPC-Deutschland-Collaboration

2016-07-01

For the planned International Linear Collider (ILC) two detectors are proposed. One of them, the International Large Detector (ILD) uses a Time Projektion Chamber (TPC) as the main tracking device. As a readout system for this TPC, pixel chips are one of the considered options. An integrated Micromegas stage is foreseen as gas amplification stage, which is built directly on top of the chip. Since first tests of a Pixel-TPC with 160 Timepix ASICs showed promising results, one is interested in developing a detector using the Timepix3 ASIC. It has several advantages, first of all its feature to measure ToT and a ToA at the same time and its significantly increased readout rate. For this purpose a readout system needs to be developed which fulfils the requirements of the Timpix3 ASIC and also has a high scalability. The main challenges are the high speed readout with a clock of up to 640 MHz and the reliability of the system. Also, the data driven as well as the frame-based readout of the Timepix3 needs to be considered for the implementation. The main goal is to provide a fast and parallel readout of several million channels. An overview and the status of the planning is given. Also, the development challenges are discussed.

Performance studies of resistive Micromegas detectors for the upgrade of the ATLAS Muon Spectrometer

CERN Document Server

ATLAS Collaboration; The ATLAS collaboration

2016-01-01

Resistive Micromegas (Micro MEsh Gaseous Structure) detectors have proven along the years to be a reliable high rate capable detector techno- logy characterised by an excellent spatial resolution. The ATLAS colla- boration at LHC has chosen the resistive Micromegas technology (mainly for tracking), along with the small-strip Thin Gap Chambers (sTGC, mainly for triggering), for the high luminosity upgrade of the inner muon station in the high-rapidity region, the so called New Small Wheel (NSW) upgrade project. The NSW requires fully efficient Micromegas chambers with spatial resolution better than 100μm independent of the track inci- dence angle and the magnetic field (B < 0.3 T), with a rate capability up to ∼ 10kHz/cm2. Along with the precise tracking the Micromegas chambers should be able to provide a trigger signal, complementary to the sTGC, thus a decent timing resolution is required. Several tests have been performed on small (10×10cm2) and medium size (1×0.5m2) resistive Micromegas chambers (b...

Radiation studies on resistive bulk-micromegas chambers at the CERN Gamma Irradiation Facility

CERN Document Server

Alvarez Gonzalez, Barbara; Camerlingo, Maria Teresa; Farina, Edoardo; Iengo, Paolo; Longo, Luigi; Samarati, Jerome; Sidiropoulou, Ourania; Wotschack, Joerg

2018-01-01

With the growing diffusion of resistive Micromegas detectors in HEP experiments the study of long-term aging behaviour is becoming more and more relevant. Two resistive bulk-Micromegas detectors were installed in May 2015 at the CERN Gamma Irradiation Facility and exposed to an intense gamma irradiation with the aim to study the detector behavior under high irradiation and the long-term aging. The detectors have an active area of 10 × 10 cm 2 , readout strip pitch of 400 μ m , amplification gap of 128 μ m and drift gap of 5 mm. The desired accumulated charge of more than 0.2 C/cm 2 has been reached for both chambers, equivalent to 10 years of HL-LHC operation. The efficiency, amplification, and resolution of the Micromegas after this long-term irradiation period is compared with the performance of a non irradiated detector. In addition, the latest results of the measured particle rate as a function of the amplification voltage is presented and compared with those obtained in 2015.

Performance studies of resistive Micromegas detectors for the upgrade of the ATLAS Muon Spectrometer

CERN Document Server

Ntekas, Konstantinos; The ATLAS collaboration

2015-01-01

Resistive Micromegas (Micro MEsh Gaseous Structure) detectors have proven along the years to be a reliable high rate capable detector technology characterised by an excellent spatial resolution. The ATLAS collaboration at LHC has chosen the resistive Micromegas technology (mainly for tracking), along with the small-strip Thin Gap Chambers (sTGC, mainly for triggering), for the high luminosity upgrade of the inner muon station in the high-rapidity region, the so called New Small Wheel (NSW) upgrade project. The NSW requires fully efficient Micromegas chambers with spatial resolution better than $100\\,\\mu\\mathrm{m}$ independent of the track incidence angle and the magnetic field ($B<0.3\\,\\mathrm{T}$), with a rate capability up to $\\sim10\\,\\mathrm{kHz/cm^2}$. Moreover, together with the precise tracking capability the Micromegas chambers should be able to provide a trigger signal, complementary to the sTGC, thus a decent timing resolution is required. Several tests have been performed on small ($10\\times10\\,\\...

Performances of Anode-resistive Micromegas for HL-LHC

Directory of Open Access Journals (Sweden)

Herlant S.

2012-06-01

Full Text Available Micromegas technology is a promising candidate to replace Atlas forward muon chambers -tracking and trigger- for future HL-LHC upgrade of the experiment. The increase on background and pile-up event probability requires detector performances which are currently under studies in intensive RD activities. We studied performances of four different resistive Micromegas detectors with different read-out strip pitches. These chambers were tested using ~120 GeV momentum pions, at H6 CERN-SPS beam line in autumn 2010. For a strip pitch 500μm we measure a resolution of ~90 μm and a efficiency of ~ 98%. The track angle effect on the efficiency was also studied. Our results show that resistive techniques induce no degradation on the efficiency or resolution, with respect to the standard Micromegas. In some configuration the resistive coating is able to reduce the discharge currents at least by a factor of 100.

Particle Identification Studies with an ALICE Test TPC

CERN Document Server

Christiansen, P

2007-01-01

Using a test TPC, consisting of the ALICE TPC field cage prototype in combination with the final ALICE TPC readout and electronics, the energy loss distribution and resolution were measured for identified protons. The measurements were compared to theoretical calculations and good quantitative agreement was found when detector effects were taken into account. The implications for particle identification are discussed.

An ageing study of resistive micromegas for the HL-LHC environment

CERN Document Server

Galan, J.; Ferrer-Ribas, E.; Giganon, A.; Giomataris, I.; Herlant, S.; Jeanneau, F.; Peyaud, A.; Schune, Ph; Alexopoulos, T.; Byszewski, M.; Iakovidis, G.; Iengo, P.; Ntekas, K.; Leontsinis, S.; de Oliveira, R.; Tsipolitis, Y.; Wotschack, J.

2013-01-01

Resistive-anode micromegas detectors are in development since several years, in an effort to solve the problem of sparks when working at high flux and high ionizing radiation like in the HL-LHC (up to ten times the luminosity of the LHC). They have been chosen as one of the technologies that will be part of the ATLAS New Small Wheel project (forward muon system). An ageing study is mandatory to assess their capabilities to handle the HL-LHC environment on a long-term period. A prototype has been exposed to several types of irradiation (X-rays, cold neutrons, $^{60}$Co gammas and alphas) above the equivalent charge produced at the detector in five HL-LHC running years without showing any degradation of the performances in terms of gain and energy resolution. This study has been completed with the characterization of the tracking performances in terms of efficiency and spatial resolution, verifying the compatibility of results obtained with both resistive micromegas detectors, irradiated and non-irradiated one.

Study of the performance of the Micromegas chambers for the ATLAS Muon Spectrometer upgrade

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00237763; The ATLAS Muon collaboration

2017-01-01

Micromegas (MICRO MEsh GAseous Structure) chambers are Micro-Pattern Gaseous Detectors designed to provide a high spatial resolution in highly irradiated environments. In 2007 an ambitious long-term R&D activity was started in the context of the ATLAS experiment, at CERN: the Muon ATLAS Micromegas Activity (MAMMA). After years of tests on prototypes and technology breakthroughs, Micromegas chambers were chosen as tracking detectors for an upgrade of the ATLAS Muon Spectrometer. These novel detectors will be installed in 2018 and 2019 during the second long shutdown of the Large Hadron Collider, and will serve as precision detectors in the innermost part of the ATLAS Muon Spectrometer. Eight layers of Micromegas modules of unprecedented size, up to 3 $\\rm{{m^2}}$, will cover a surface of 150 $\\rm{{m^2}}$ for a total active area of about 1200 $\\rm{{m^2}}$. This upgrade will be crucial to ensure high quality performance for the ATLAS Muon Spectrometer in view of the third run of the Large Hadron Collider and...

Accurate gamma and MeV-electron track reconstruction with an ultra-low diffusion Xenon/TMA TPC at 10 atmospheres

CERN Document Server

González-Díaz, Diego; Borges, F.I.G.; Camargo, M.; Cárcel, S.; Cebrián, S.; Cervera, A.; Conde, C.A.N.; Dafni, T.; Díaz, J.; Esteve, R.; Fernandes, L.M.P.; Ferrario, P.; Ferreira, A.L.; Freitas, E.D.C.; Gehman, V.M.; Goldschmidt, A.; Gómez-Cadenas, J.J.; Gutiérrez, R.M.; Hauptman, J.; Hernando Morata, J.A.; Herrera, D.C.; Irastorza, I.G.; Labarga, L.; Laing, A.; Liubarsky, I.; Lopez-March, N.; Lorca, D.; Losada, M.; Luzón, G.; Marí, A.; Martín-Albo, J.; Martínez-Lema, G.; Martínez, A.; Miller, T.; Monrabal, F.; Monserrate, M.; Monteiro, C.M.B.; Mora, F.J.; Moutinho, L.M.; Muñoz Vidal, J.; Nebot-Guinot, M.; Nygren, D.; Oliveira, C.A.B.; Pérez, J.; Pérez Aparicio, J.L.; Querol, M.; Renner, J.; Ripoll, L.; Rodríguez, J.; Santos, F.P.; dos Santos, J.M.F.; Serra, L.; Shuman, D.; Simón, A.; Sofka, C.; Sorel, M.; Toledo, J.F.; Torrent, J.; Tsamalaidze, Z.; Veloso, J.F.C.A.; Villar, J.A.; Webb, R.; White, J.T.; Yahlali, N.; Azevedo, C.; Aznar, F.; Calvet, D.; Castel, J.; Ferrer-Ribas, E.; García, J.A.; Giomataris, I.; Gómez, H.; Iguaz, F.J.; Lagraba, A.; Le Coguie, A.; Mols, J.P.; Şahin, Ö.; Rodríguez, A.; Ruiz-Choliz, E.; Segui, L.; Tomás, A.; Veenhof, R.

2015-01-01

We report the performance of a 10 atm Xenon/trimethylamine time projection chamber (TPC) for the detection of X-rays (30 keV) and gamma-rays (0.511-1.275 MeV) in conjunction with the accurate tracking of the associated electrons. When operated at such a high pressure and in 1%-admixtures, trimethylamine (TMA) endows Xenon with an extremely low electron diffusion (1.3 +-0.13 mm-sigma (longitudinal), 0.8 +-0.15 mm-sigma (transverse) along 1 m drift) besides forming a convenient Penning-Fluorescent mixture. The TPC, that houses 1.1 kg of gas in its active volume, operated continuously for 100 live-days in charge amplification mode. The readout was performed through the recently introduced microbulk Micromegas technology and the AFTER chip, providing a 3D voxelization of 8mm x 8mm x 1.2mm for approximately 10 cm/MeV-long electron tracks. This work was developed as part of the R&D program of the NEXT collaboration for future detector upgrades in the search of the 0bbnu decay in 136Xe, specifically those based ...

Development of Micromegas detectors for the CLAS12 experiment at Jefferson Laboratory

CERN Document Server

Charles, Gabriel

This thesis presents my work performed since 2010 to develop Micromegas detectors for the CLAS12 spectrometer that will be installed in the Hall B of Jefferson Laboratory (USA). The Micromegas are robust, fast and cheap gaseous detectors. Nevertheless, they must be adapted to the specific CLAS12 environment as there are many challenges to face : presence of a strong magnetic field, off-detector frontend electronics, high hadrons rate, necessity to curve the detectors, few space available. My PhD started by beam tests at CERN that allowed to evaluate the spark rate in CLAS12 Micromegas at a few Hertz. An important part of this document is therefore devoted to the study of several innovative methods to minimize the dead time induced by sparks. Thus, I have performed intensive tests on the optimization of the micromesh high voltage filter, with on Micromegas equipped with a GEM foild or on resistive Micromegas. The latter giving excellent results, full scale prototypes, one of which built by a company, have been...

Comparison of bulk Micromegas with different amplification gaps

Energy Technology Data Exchange (ETDEWEB)

Bhattacharya, Purba, E-mail: purba.bhattacharya@saha.ac.in [Applied Nuclear Physics Division, Saha Institute of Nuclear Physics, Kolkata 700064 (India); Bhattacharya, Sudeb [Emeritus Scientist (CSIR), Applied Nuclear Physics Division, Saha Institute of Nuclear Physics, Kolkata 700064 (India); Majumdar, Nayana; Mukhopadhyay, Supratik; Sarkar, Sandip [Applied Nuclear Physics Division, Saha Institute of Nuclear Physics, Kolkata 700064 (India); Colas, Paul; Attie, David [DSM/IRFU, CEA/Saclay, F-91191 Gif-sur-Yvette CEDEX (France)

2013-12-21

The bulk Micromegas detector is considered to be a promising candidate for building TPCs for several future experiments including the projected linear collider. The standard bulk with a spacing of 128μm has already established itself as a good choice for its performances in terms of gas gain uniformity, energy and space point resolution, and its capability to efficiently pave large readout surfaces with minimum dead zone. The present work involves the comparison of this standard bulk with a relatively less used bulk Micromegas detector having a larger amplification gap of 192μm. Detector gain, energy resolution and electron transparency of these Micromegas have been measured under different conditions in various Argon-based gas mixtures to evaluate their performance. These measured characteristics have also been compared in detail to numerical simulations using the Garfield framework that combines packages such as neBEM, Magboltz and Heed. Further, we have carried out another numerical study to determine the effect of dielectric spacers on different detector features. A comprehensive comparison of the two detectors has been presented and analyzed in this work. -- Highlights: •We present a comparative study between bulk Micromegas having different amplification gaps. •Various detector characteristics such as gain, electron transparency, energy resolution have been measured experimentally. •Successful comparisons of these measured data with the simulation results indicate that the device physics is quite well understood. •A numerical study to determine the effect of dielectric spacers on different detect or features has been carried out.

New micromegas for axion searches in CAST

International Nuclear Information System (INIS)

Dafni, T.; Aune, S.; Fanourakis, G.; Ferrer-Ribas, E.; Galan, J.; Gardikiotis, A.; Geralis, T.; Giomataris, I.; Gomez, H.; Iguaz, F.J.; Irastorza, I.G.; Luzon, G.; Morales, J.; Papaevangelou, T.; Rodriguez, A.; Ruz, J.; Tomas, A.; Vafeiadis, T.; Yildiz, S.C.

2011-01-01

Micromegas detectors have been taking data in the CAST experiment since 2002, occupying one opening (out of the two looking for sunrise axions) of the magnet and showing good performance and stability. Currently, three of the four X-ray detectors used in the experiment are micromegas. The new detectors are of the Microbulk technology, which have attracted a lot of attention because of the advantages they present, among them the low-material construction, high radiopurity and good energy resolution. Here, their performance during the last year will be commented. In particular, the low background levels reached in some detectors have triggered a set of studies in order to understand the effect.

Studies of MicroMegas Chamber for the New Small Wheel using Cosmic Muons

CERN Document Server

Klapdor-kleingrothaus, Thorwald; The ATLAS collaboration

2016-01-01

Micromesh Gaseous (MicroMegas) Detectors will be implemented in the ATLAS detector in the framework of the New Small Wheel Upgrade during the long shut down II in 2019/20. These detectors are used for position measurement and have a high spatial resolution of 100$\\mu$m. In parallel to the ongoing constructions of the later modules, additional performance studies with small MicroMegas prototypes of a size of 10 $\\times$ 10 cm$^2$ are performed. The studies include a cosmic muon test stand in combination with a scalable readout system, such that the influences of variations in the pressure of the operation gas or changes in the humidity at the lower ppm level to the detector performance are investigated. These parameters will impact the later design of detector slow control system at the New Small Wheel in ATLAS.

The ALICE TPC Upgrad

Science.gov (United States)

Castro, Andrew; Alice-Usa Collaboration; Alice-Tpc Collaboration

2017-09-01

The Time Projection Chamber (TPC) currently used for ALICE (A Large Ion Collider Experiment at CERN) is a gaseous tracking detector used to study both proton-proton and heavy-ion collisions at the Large Hadron Collider (LHC) In order to accommodate the higher luminosit collisions planned for the LHC Run-3 starting in 2021, the ALICE-TPC will undergo a major upgrade during the next LHC shut down. The TPC is limited to a read out of 1000 Hz in minimum bias events due to the intrinsic dead time associated with back ion flow in the multi wire proportional chambers (MWPC) in the TPC. The TPC upgrade will handle the increase in event readout to 50 kHz for heavy ion minimum bias triggered events expected with the Run-3 luminosity by switching the MWPCs to a stack of four Gaseous Electron Multiplier (GEM) foils. The GEM layers will combine different hole pitches to reduce the dead time while maintaining the current spatial and energy resolution of the existing TPC. Undertaking the upgrade of the TPC represents a massive endeavor in terms of design, production, construction, quality assurance, and installation, thus the upgrade is coordinated over a number of institutes worldwide. The talk will go over the physics motivation for the upgrade, the ALICE-USA contribution to the construction of Inner Read Out Chambers IROCs, and QA from the first chambers built in the U.S

Development and characterization of micro-pattern gas detectors for intense beams of hadrons

Energy Technology Data Exchange (ETDEWEB)

Vandenbroucke, Maxence

2012-07-02

This thesis work is dedicated to the design, development and characterization of Micro-Pattern Gas Detectors. The performances of a Time Projection Chamber (TPC) equipped with a triple Gas Electron Multiplier (GEM) amplification structure are reported. The intrinsic ion backflow suppression of GEM foils drastically reduces the space charge produced by wire readout in traditional TPC. The GEM solution allows the operation of a TPC at much higher event rate. The second part of this thesis describes the development of a 40 x 40 cm{sup 2} Micromegas detector with a highly segmented central area. A reduction of discharges compared to conventional Micromegas detectors is needed for stable operation in intense beams of hadrons. Spark reduction technologies have been successfully studied and results are presented.

Development and characterization of micro-pattern gas detectors for intense beams of hadrons

International Nuclear Information System (INIS)

Vandenbroucke, Maxence

2012-01-01

This thesis work is dedicated to the design, development and characterization of Micro-Pattern Gas Detectors. The performances of a Time Projection Chamber (TPC) equipped with a triple Gas Electron Multiplier (GEM) amplification structure are reported. The intrinsic ion backflow suppression of GEM foils drastically reduces the space charge produced by wire readout in traditional TPC. The GEM solution allows the operation of a TPC at much higher event rate. The second part of this thesis describes the development of a 40 x 40 cm 2 Micromegas detector with a highly segmented central area. A reduction of discharges compared to conventional Micromegas detectors is needed for stable operation in intense beams of hadrons. Spark reduction technologies have been successfully studied and results are presented.

Imaging antimatter with a Micromegas detector

Science.gov (United States)

Mäckel, V.; Radics, B.; Dupre, P.; Higaki, H.; Kanai, Y.; Kuroda, N.; Matsuda, Y.; Nagata, Y.; Tajima, M.; Widmann, E.; Yamazaki, Y.

2018-05-01

The ASACUSA collaboration aims at measuring the ground state hyperfine splitting of antihydrogen for probing fundamental symmetries. A cryogenic trap for mixing antiprotons and positrons serves as an antihydrogen source for in-flight spectroscopy. In order to be able to monitor the antihydrogen formation process, a dedicated Micromegas tracking detector has been designed and built to record the annihilation distribution in the trap. In this paper, we present the first results from antiproton annihilation data recorded with the Micromegas, together with a description of the event reconstruction algorithm.

Development of Micromegas detectors for the CLAS12 experiment at Jefferson Laboratory

International Nuclear Information System (INIS)

Charles, Gabriel

2013-01-01

This thesis presents my work performed since 2010 to develop Micromegas detectors for the CLAS12 spectrometer that will be installed in the Hall B of Jefferson Laboratory (USA). The Micromegas are robust, fast and cheap gaseous detectors. Nevertheless, they must be adapted to the specific CLAS12 environment as there are many challenges to face: presence of a strong magnetic field, off-detector front end electronics, high hadrons rate, necessity to curve the detectors, few space available. My PhD started by beam tests at CERN that allowed to evaluate the spark rate in CLAS12 Micromegas at a few Hertz. An important part of this document is therefore devoted to the study of several innovative methods to minimize the dead time induced by sparks. Thus, I have performed intensive tests on the optimization of the micro-mesh high voltage filter, with on Micromegas equipped with a GEM foil or on resistive Micromegas. The latter giving excellent results, full scale prototypes, one of which built by a company, have been tested. The mechanics and the working point (gas, voltages, geometry...) of the detectors have then be validated by laboratory tests. However, to ensure a better signal over noise ratio, the micro-mesh has been optimized. The CEA Saclay being also responsible for the development of the electronics for CLAS12 Micromegas, I have compared its performance with another electronics, verify its time resolution and determine the signal over noise ratio when 2 m long cables are connecting the electronics to the detector. The progress realized in the context of CLAS12 have furthermore triggered other projects. So, I have carried out simulations based on pseudo-data to validate the feasibility of a meson spectroscopy experiment for which we have proposed a Micromegas based tracker. (author) [fr

Studies of MicroMeGas Chambers for the New Small Wheel using Cosmic Muons

CERN Document Server

Klapdor-kleingrothaus, Thorwald; The ATLAS collaboration

2016-01-01

Micromesh Gaseous Detectors (MicroMeGas) will be implemented in the ATLAS detector in the framework of the New Small Wheel Upgrade during the long shut down II in 2019/20. These detectors are used for position measurement and have a high spatial resolution of 100 μm. In parallel to the ongoing constructions of the later modules, additional performance studies with small MicroMeGas prototypes of a size of 10 × 10 cm$^2$ are performed. These studies include a cosmic muon test setup in combination with a scalable readout system, such that the influences of variations in the pressure of the operation gas or changes in the humidity at the lower ppm level to the detector performance are investigated. These parameters will impact the later design of the slow control system at the New Small Wheel in ATLAS.

Resistive-strips micromegas detectors with two-dimensional readout

Science.gov (United States)

Byszewski, M.; Wotschack, J.

2012-02-01

Micromegas detectors show very good performance for charged particle tracking in high rate environments as for example at the LHC. It is shown that two coordinates can be extracted from a single gas gap in these detectors. Several micromegas chambers with spark protection by resistive strips and two-dimensional readout have been tested in the context of the R&D work for the ATLAS Muon System upgrade.

Performance studies of resistive Micromegas chambers for the upgrade of the ATLAS Muon Spectrometer

Science.gov (United States)

Ntekas, Konstantinos

2018-02-01

The ATLAS collaboration at LHC has endorsed the resistive Micromegas technology (MM), along with the small-strip Thin Gap Chambers (sTGC), for the high luminosity upgrade of the first muon station in the high-rapidity region, the so called New Small Wheel (NSW) project. The NSW requires fully efficient MM chambers, up to a particle rate of ˜ 15 kHz/cm2, with spatial resolution better than 100 μm independent of the track incidence angle and the magnetic field (B ≤ 0.3 T). Along with the precise tracking the MM should be able to provide a trigger signal, complementary to the sTGC, thus a decent timing resolution is required. Several tests have been performed on small (10 × 10 cm2) MM chambers using medium (10 GeV/c) and high (150 GeV/c) momentum hadron beams at CERN. Results on the efficiency and position resolution measured during these tests are presented demonstrating the excellent characteristics of the MM that fulfil the NSW requirements. Exploiting the ability of the MM to work as a Time Projection Chamber a novel method, called the μTPC, has been developed for the case of inclined tracks, allowing for a precise segment reconstruction using a single detection plane. A detailed description of the method along with thorough studies towards refining the method's performance are shown. Finally, during 2014 the first MM quadruplet (MMSW) following the NSW design scheme, comprising four detection planes in a stereo readout configuration, has been realised at CERN. Test-beam results of this prototype are discussed and compared to theoretical expectations.

The MicrOmega Investigation Onboard Hayabusa2

Science.gov (United States)

Bibring, J.-P.; Hamm, V.; Langevin, Y.; Pilorget, C.; Arondel, A.; Bouzit, M.; Chaigneau, M.; Crane, B.; Darié, A.; Evesque, C.; Hansotte, J.; Gardien, V.; Gonnod, L.; Leclech, J.-C.; Meslier, L.; Redon, T.; Tamiatto, C.; Tosti, S.; Thoores, N.

2017-07-01

MicrOmega is a near-IR hyperspectral microscope designed to characterize in situ the texture and composition of the surface materials of the Hayabusa2 target asteroid. MicrOmega is implemented within the MASCOT lander (Ho et al. in Space Sci. Rev., 2016, this issue, doi:10.1007/s11214-016-0251-6). The spectral range (0.99-3.65 μm) and the spectral sampling (20 cm^{-1}) of MicrOmega have been chosen to allow the identification of most potential constituent minerals, ices and organics, within each 25 μm pixel of the 3.2× 3.2 mm2 FOV. Such an unprecedented characterization will (1) enable the identification of most major and minor phases, including the potential organic phases, and ascribe their mineralogical context, as a critical set of clues to decipher the origin and evolution of this primitive body, and (2) provide the ground truth for the orbital measurements as well as a reference for the analyses later performed on returned samples.

An Integration of MICROMEGAS Based Muon Tracking Chambers in ALICE

CERN Document Server

Cussonneau, J P; CERN. Geneva

1999-01-01

A global solution for the muon tracking chambers of ALICE based on the detector MICROMEGAS [1], is investigated at SUBATECH. A technical design of the structures of the MICROMEGAS modules is presented as well as their assemblies in individual chamber and their final integration in the five tracking stations required for the muon spectrometer. The whole concept is based on only 3 kinds of MICROMEGAS units. Within these stand-alone modules, the 2D location is achieved by taking advantage of charge division with resistive strips. Including the support frames for the mosaic of detectors, the average station thickness will stay below 3% of Xo. The whole electronics features about 1.3 106 channels. Preliminary considerations on the MICROMEGAS FEE and its on-board integration are discussed. A first estimation of the total cost of this option stays well inside the assigned budget of the technical proposal.

A micromegas detector for {sup 222}Rn emanations measurements

Energy Technology Data Exchange (ETDEWEB)

García, J. A.; Garza, J. G.; Irastorza, I. G.; Mirallas, H. [Laboratorio de Física Nuclear y Altas Energías, Universidad de Zaragoza, Zaragoza (Spain)

2013-08-08

The {sup 222}Rn emanation has significant contribution in the overall background for rare event searches experiments. In order to measure this emanations a high sensitivity detector has been designed. The detection method is based on the electrostatic collection of the {sup 222}Rn daughters on a Micromegas detector. Using a chamber with a volume of 21.2 l for the collection of {sup 218}Po and {sup 214}Po progeny of {sup 222}Rn and a 12 × 12cm{sup 2} pixelized Micromegas for the α detection. The advantages of the Micromegas detectors are the low intrinsic radioactivity and the track reconstruction of the α’s, having excellent capabilities for event discrimination.

Performances and ageing study of resistive-anodes Micromegas detectors for HL-LHC environment

CERN Document Server

Jeanneau, F; Attié, D; Boyer, M; Derré, J; Fanourakis, G; Ferrer-Ribas, E; Galán, J; Gazis, E; Geralis, T; Giganon, A; Giomataris, I; Herlant, S; Manjarrés, J; Ntomari, E; Schune, Ph; Titov, M; Tsipolitis, G

2012-01-01

With the tenfold luminosity increase envisaged at the HL-LHC, the background (photons, neutrons, ...) and the event pile-up probability are expected to increase in proportion in the different experiments, especially in the forward regions like, for instance, the muons chambers of the ATLAS detector. Detectors based on the Micromegas principle should be good alternatives for the detector upgrade in the HL-LHC framework because of a good spatial ( 98%) can be achieved with resistive-anode micromegas detector. An X-rays irradiation has been also performed, showing no ageing effect after more than 21 days exposure and an integrated charge of almost 1C.

Performances of anode-resistive Micromegas for HL-LHC

International Nuclear Information System (INIS)

Manjarrés, J; Attié, D; Boyer, M; Derré, J; Ferrer-Ribas, E; Galán, J; Giganon, A; Giomataris, I; Herlant, S; Jeanneau, F; Schune, Ph; Titov, M; Alexopoulos, T; Gazis, E; Tsipolitis, G; Fanourakis, G; Geralis, T

2012-01-01

Micromegas technology is a promising candidate to replace Atlas forward muon chambers -tracking and trigger- for future HL-LHC upgrade of the experiment. The LHC accelerator luminosity will be ten times the nominal one, increasing background and pile-up event probability in the same proportion. This requires detector performances which are currently under studies in intensive RD activities. We studied performances of four different resistive Micromegas detectors and with different read-out strip pitches. These chambers were tested using ∼ 120 GeV momentum pions with rates from 25 up to 250 kHz/cm 2 , at H6 CERN-SPS beam line in autumn 2010. We found that the resolution is degraded, if the strip pitch is too wide with respect to the charge distribution at the readout plane. To reduce the systematic effects of the charge sharing we propose a cluster reconstruction algorithm. For narrow strip pitch 500μm we measure a resolution of ∼ 90 μm and a efficiency of ∼ 98%. The track angle effect on the efficiency was also studied. Our results show that resistive techniques induce no degradation on the efficiency or resolution, with respect to the standard Micromegas. In some configuration the resistive coating is able to reduce the discharge currents at least by a factor of 100 and no HV breakdown was observed.

R3B time projection chamber

Directory of Open Access Journals (Sweden)

Legou P.

2012-07-01

Full Text Available Within the international FAIR project, the R3B collaboration (Reaction studies with Radioactive Relativistic beams will be in charge of the physics program with secondary beams of energy between 200 and 1500MeV per nucleon. Central to the R3B set-up will be a large-aperture superconducting magnet under construction at CEA-Saclay. An international collaboration has been formed to work on the design of a large time-projection chamber (TPC to be installed behind this magnet to cover the full phase-space of the charged fragments produced in the target. Within this collaboration, tests of detector prototypes were performed with the heavy-ions beams at GSI Darmstadt. These prototypes were equipped with a gaseous Micromegas detector. Two amplification technologies were tested, either conventional or resistive Micromegas and two construction concepts, bulk-Micromegas or micro-meshes screwed on the PCB. We will present the results of the last beam and the 1m TPC station which will be dedicated to make tests using the real drift distance and compare the performances of micromegas and GEM.

Study of the physical processes involved in the operating mode of the micro-strips gas detector Micromegas; Analyse des phenomenes physiques lies au fonctionnement du detecteur gazeux a micropistes micromegas

Energy Technology Data Exchange (ETDEWEB)

Barouch, G

2001-04-01

Micromegas is a micro-strip gaseous detector invented in 1996. It consists of two volumes of gas separated by a micro-mesh. The first volume of gas, 3 mm thick, is used to liberate ionization electrons from the incident charged particle. In the second volume, only 100 {mu}m thick, an avalanche phenomenon amplifies the electrons produced in the first volume. Strips printed on an insulating substrate collect the electrons from the avalanche. The geometrical configuration of Micromegas showed many advantages. The short anode-cathode distance combined with a high granularity provide high rate capabilities due to a fast collection of ions produced during the avalanche development. Moreover, the possibility to localize the avalanche with strips printed about every hundreds of micrometers allows to measure the position of the incident particle with a good resolution. In this work, experimental tests of Micromegas are presented along with detailed Monte Carlo simulations used to understand and optimize the detector's performances. The prototypes were tested several times at the PS accelerator at CERN. The analysis of the date showed a stable and efficient behavior of Micromegas combined with an excellent space resolution. In fact, spatial resolutions of less than 15 {mu}m were obtained. In parallel with the in-beam tests, several simulations have been developed in order to gain a better understanding of the detector's response. (author)

Development of MicroMegas for a Digital Hadronic Calorimeter

OpenAIRE

Adloff, Catherine; Blaha, Jan; Espargiliere, Ambroise; Karyotakis, Yannis

2009-01-01

Recent developments on the MicroMegas prototypes built by use of the bulk technology with analog and digital readout electronics are presented. The main test beam results of a stack of several MicroMegas prototypes fully comply with the needs of a hadronic calorimeter for future particle physics experiments. A technical solution for a large scale prototype is also introduced.

Development of large area resistive electrodes for ATLAS NSW Micromegas

Science.gov (United States)

Ochi, Atsuhiko

2018-02-01

Micromegas with resistive anodes will be used for the NSW upgrades of the ATLAS experiment at LHC. Resistive electrodes are used in MPGD devices to prevent sparks in high-rate operation. Large-area resistive electrodes for Micromegas have been developed using two different technologies: screen printing and carbon sputtering. The maximum resistive foil size is 45 × 220 cm with a printed pattern of 425-μm pitch strips. These technologies are also suitable for mass production. Prototypes of a production model series have been successfully produced. In this paper, we report the development, the production status, and the test results of resistive Micromegas.

TPC magnet cryogenic system

International Nuclear Information System (INIS)

Green, M.A.; Burns, W.A.; Taylor, J.D.; Van Slyke, H.W.

1980-03-01

The Time Projection Chamber (TPC) magnet at LBL and its compensation solenoids are adiabatically stable superconducting solenoid magnets. The cryogenic system developed for the TPC magnet is discussed. This system uses forced two-phase tubular cooling with the two cryogens in the system. The liquid helium and liquid nitrogen are delivered through the cooled load by forced tubular flow. The only reservoirs of liquid cryogen exist in the control dewar (for liquid helium) and the conditioner dewar (for liquid nitrogen). The operation o these systems during virtually all phases of system operation are described. Photographs and diagrams of various system components are shown, and cryogenic system data are presented in the following sections: (1) heat leaks into the TPC coil package and the compensation solenoids; (2) heat leaks to various components of the TPC magnet cryogenics system besides the magnets and control dewar; (3) the control dewar and its relationship to the rest of the system; (4) the conditioner system and its role in cooling down the TPC magnet; (5) gas-cooled electrical leads and charging losses; and (6) a summation of the liquid helium and liquid nitrogen requirements for the TPC superconducting magnet system

The ASACUSA Micromegas Tracker: A cylindrical, bulk Micromegas detector for antimatter research

Energy Technology Data Exchange (ETDEWEB)

Radics, B., E-mail: balint.radics@riken.jp; Nagata, Y.; Yamazaki, Y. [Atomic Physics Laboratory, RIKEN, Saitama 351-0198 (Japan); Ishikawa, S.; Kuroda, N.; Matsuda, Y. [Institute of Physics, Graduate School of Arts and Sciences, University of Tokyo, Tokyo 153-8902 (Japan); Anfreville, M.; Aune, S.; Boyer, M.; Chateau, F.; Combet, M.; Granelli, R.; Legou, P.; Mandjavidze, I.; Procureur, S.; Riallot, M.; Vallage, B.; Vandenbroucke, M. [Irfu, CEA, Centre de Saclay, 91191 Gif sur Yvette (France)

2015-08-15

The ASACUSA Micromegas Tracker (AMT; ASACUSA: Atomic Spectroscopy and Collisions Using Slow Antiprotons) was designed to be able to reconstruct antiproton-nucleon annihilation vertices in three dimensions. The goal of this device is to study antihydrogen formation processes in the ASACUSA cusp trap, which was designed to synthesise a spin-polarised antihydrogen beam for precise tests of Charge, Parity, and Time (CPT) symmetry invariance. This paper discusses the structure and technical details of an AMT detector built into such an environment, its data acquisition system and the first performance with cosmic rays.

The ASACUSA Micromegas Tracker: A cylindrical, bulk Micromegas detector for antimatter research.

Science.gov (United States)

Radics, B; Nagata, Y; Yamazaki, Y; Ishikawa, S; Kuroda, N; Matsuda, Y; Anfreville, M; Aune, S; Boyer, M; Chateau, F; Combet, M; Granelli, R; Legou, P; Mandjavidze, I; Procureur, S; Riallot, M; Vallage, B; Vandenbroucke, M

2015-08-01

The ASACUSA Micromegas Tracker (AMT; ASACUSA: Atomic Spectroscopy and Collisions Using Slow Antiprotons) was designed to be able to reconstruct antiproton-nucleon annihilation vertices in three dimensions. The goal of this device is to study antihydrogen formation processes in the ASACUSA cusp trap, which was designed to synthesise a spin-polarised antihydrogen beam for precise tests of Charge, Parity, and Time (CPT) symmetry invariance. This paper discusses the structure and technical details of an AMT detector built into such an environment, its data acquisition system and the first performance with cosmic rays.

Advancements of floating strip Micromegas detectors for medical imaging applications

Energy Technology Data Exchange (ETDEWEB)

Klitzner, Felix; Biebel, Otmar; Bortfeldt, Jonathan; Flierl, Bernhard [LS Schaile, LMU Muenchen (Germany); Magallanes, Lorena [LS Parodi, LMU Muenchen (Germany); Universitaetsklinikum Heidelberg (Germany); Parodi, Katia [LS Parodi, LMU Muenchen (Germany); Heidelberger Ionenstrahl Therapiezentrum (Germany); Voss, Bernd [Gesellschaft fuer Schwerionenforschung, Darmstadt (Germany)

2016-07-01

Floating strip Micromegas have proven to be high-rate capable tracking detectors with excellent spatial and temporal resolution for particle fluxes up to 7 MHz/cm{sup 2}. To further increase the high-rate capability a Ne:CF{sub 4} 86:14 vol.% gas mixture has been used as detector gas. We present results from measurements with a seven detector system consisting of six low material budget floating strip Micromegas, a GEM detector and a scintillator based particle range telescope. The gaseous and the scintillation detectors were read out with APV25 frontend boards, allowing for single strip readout with pulse height and timing information. A two-dimensional readout anode for floating strip Micromegas has been tested for the first time. The Micromegas detectors were operated with minimal additional drift field, which significantly improves the timing resolution and also the spatial resolution for inclined tracks. We discuss the detector performance in high-rate carbon and proton beams at the Heidelberg Ion Beam Therapy Center (HIT) and present radiographies of phantoms, acquired with the system.

Spatial resolution studies of a GEM-TPC

Energy Technology Data Exchange (ETDEWEB)

Berger, Martin [TU Muenchen, 85748 Garching (Germany); Collaboration: GEM-TPC-Collaboration

2015-07-01

A GEM-TPC can exploit the intrinsic suppression of back drifting ions from the amplification stage of the GEM (Gas Electron Multiplier) foils to overcome the problem of drift-field distortions in an ungated operation. To explore the possibility of such a continuously running TPC (Time Projection Chamber) a large-size detector was built. This detector, with a drift length of 728 mm and a radius of 308 mm and a total of 10254 electronic channels, was designed as an upgrade for the FOPI experiment at GSI (Darmstadt, Germany) to improve the secondary vertex resolution especially for K{sup 0}{sub S}- and Λ-reconstruction and the PID capabilities. After commissioning a large statistics of cosmic data and beam-target reactions has been collected and the obtained tracks in the TPC have been used to improve the tracking algorithms. During the track finding and fitting procedure a clustering algorithm which takes into account the track topology as well as the full 3D spatial information is employed. The the clustering algorithm, the cluster error calculation and the tracking resolution are discussed in this contribution.

Development of micromegas muon chambers for the ATLAS upgrade

Science.gov (United States)

Wotschack, J.

2012-02-01

Large-area particle detectors based on the bulk-micromegas technology are an attractive choice for the upgrade of LHC detectors and/or detectors for the ILC or other experiments. In the context of the R&D for the ATLAS Muon System upgrade, we have built detectors of order 1 m2. In order to overcome the spark problem in micromegas a novel protection scheme using resistive strips above the readout electrode has been developed. This technology has undergone extensive tests with hadron beams at the CERN-SPS, X-rays in the lab, as well as in a neutron beam. In addition, four 10 × 10 cm2 micromegas chambers have been installed in the ATLAS cavern and are taking data under LHC conditions. We will discuss the underlying design of the chambers and present results on the performance of these chambers.

Development of micromegas muon chambers for the ATLAS upgrade

International Nuclear Information System (INIS)

Wotschack, J

2012-01-01

Large-area particle detectors based on the bulk-micromegas technology are an attractive choice for the upgrade of LHC detectors and/or detectors for the ILC or other experiments. In the context of the R and D for the ATLAS Muon System upgrade, we have built detectors of order 1 m 2 . In order to overcome the spark problem in micromegas a novel protection scheme using resistive strips above the readout electrode has been developed. This technology has undergone extensive tests with hadron beams at the CERN-SPS, X-rays in the lab, as well as in a neutron beam. In addition, four 10 × 10 cm 2 micromegas chambers have been installed in the ATLAS cavern and are taking data under LHC conditions. We will discuss the underlying design of the chambers and present results on the performance of these chambers.

New pixelized Micromegas detector with low discharge rate for the COMPASS experiment

CERN Document Server

Neyret, D.; Anfreville, M.; Bedfer, Y.; Burtin, E.; Coquelet, C.; d'Hose, N.; Desforge, D.; Giganon, A.; Jourde, D.; Kunne, F.; Magnon, A.; Makke, N.; Marchand, C.; Paul, B.; Platchkov, S.; Thibaud, F.; Usseglio, M.; Vandenbroucke, M.

2012-01-01

New Micromegas (Micro-mesh gaseous detectors) are being developed in view of the future physics projects planned by the COMPASS collaboration at CERN. Several major upgrades compared to present detectors are being studied: detectors standing five times higher luminosity with hadron beams, detection of beam particles (flux up to a few hundred of kHz/mm^{2}, 10 times larger than for the present Micromegas detectors) with pixelized read-out in the central part, light and integrated electronics, and improved robustness. Two solutions of reduction of discharge impact have been studied, with Micromegas detectors using resistive layers and using an additional GEM foil. Performance of such detectors has also been measured. A large size prototypes with nominal active area and pixelized read-out has been produced and installed at COMPASS in 2010. In 2011 prototypes featuring an additional GEM foil, as well as an resistive prototype, are installed at COMPASS and preliminary results from those detectors presented very go...

PandaX-III neutrinoless double beta decay experiment

Science.gov (United States)

Wang, Shaobo; PandaX-III Collaboration

2017-09-01

The PandaX-III experiment uses high pressure Time Projection Chambers (TPCs) to search for neutrinoless double-beta decay of Xe-136 with high energy resolution and sensitivity at the China Jin-Ping underground Laboratory II (CJPL-II). Fine-pitch Microbulk Micromegas will be used for charge amplification and readout in order to reconstruct both the energy and track of the neutrinoless double-beta decay event. In the first phase of the experiment, the detector, which contains 200 kg of 90% Xe-136 enriched gas operated at 10 bar, will be immersed in a large water tank to ensure 5 m of water shielding. For the second phase, a ton-scale experiment with multiple TPCs will be constructed to improve the detection probability and sensitivity. A 20-kg scale prototype TPC with 7 Micromegas modules has been built to optimize the design of Micromegas readout module, study the energy calibration of TPC and develop algorithm of 3D track reconstruction.

ALICE installs its TPC

CERN Multimedia

2007-01-01

The ALICE time projection chamber has been transported to the experimental cavern. The handling of this extremely fragile detector was a long and delicate process. The lorry transporting the TPC took one hour to travel from the assembly hall to the access shaft...200 metres away.The TPC was lowered into the ALICE experimental cavern with extreme care. The gap between the structure and the shaft wall was only 10 centimetres! For ALICE the year started with a flurry of activity...but at a snail's pace. On 8 January, the day CERN reopened after the end-of-year break, teams from ALICE and the TS Department began the transportation of the experiment's time projection chamber (TPC), the largest ever built. This 5-metre long and 5-m diameter cylinder was transported from the clean room where it had been assembled to the experimental cavern. The 300-metre journey took no less than four days! Since the TPC is an extremely fragile object, the utmost precautions were exercised in its transportation. The TPC, which is d...

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

International Nuclear Information System (INIS)

Tsionou, Dimitra

2017-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2017-02-11

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

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

International Nuclear Information System (INIS)

Tsionou, Dimitra

2016-12-01

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

MicrOmega IR: a new infrared hyperspectral imaging microscope or in situ analysis

Science.gov (United States)

Vaitua, Leroi; Bibring, Jean-Pierre; Berthé, Michel

2017-11-01

MicrOmega IR is an ultra miniaturized Near Infrared hyperspectral microscope for in situ analysis of samples. It is designed to be implemented on board space planetary vehicles (lander and/or rovers). It acquires images of samples typically some 5 mm in width with a spatial sampling of 20 μm. On each pixel, MicrOmega acquires the spectrum in the spectral range 0.9 - 2.6 μm, with a possibility to extend the sensibility up to 4 μm. The spectrum will be measured in up to 300 contiguous spectral channels (600 in the extended range): given the diagnostic spectral features present in this domain, it provides the composition of each spatially resolved constituent. MicrOmega has thus the potential to identify: minerals, such as pyroxene and olivine, ferric oxides, hydrated phases such as phyllosilicates, sulfates and carbonates, ices and organics. The composition of the various phases within a given sample is a critical record of its formation and evolution. Coupled to the mapping information, it provides unique clues to describe the history of the parent body. In particular, the capability to identify hydrated grains and to characterize their adjacent phases has a huge potential in the search for potential bio-relics in Martian samples. This purely non destructive characterization enables further analyses (e.g. through mass spectrometry) to be performed, and/or to contribute to sample selection to return to Earth. MicrOmega IR is coupled to a visible microscope: MicrOmega VIS. Thus, the MicrOmega instrument is developed by an international consortium: IAS (Orsay, France), LESIA (Meudon, France), CBM (Orléans, France), University Of Bern (Bern, Switzerland), IKI (Moscow, Russia). This instrument (MicrOmega IR, MicrOmega VIS and the electronics) is selected for the ESA Exomars mission (launch scheduled for 2013). MicrOmega IR will be used in a reduced spectral range (0.9 - 2.6 μm), due to power, mass and thermal constraints: however, most minerals and other

Study of APV preamplifier circuits for Micromegas detectors

Energy Technology Data Exchange (ETDEWEB)

Steinbacher, Quirin; Biebel, Otmar; Bortfeldt, Jonathan; Hertenberger, Ralf; Loesel, Philipp; Mueller, Ralph; Zibell, Andre [LMU Muenchen (Germany)

2016-07-01

Micromegas detectors are high-rate capable planar gaseous particle detectors with micro structured readout-anodes. The electronic signals are often read out using the analogue frontend chip APV25. An APV25 chip amplifies, buffers in a pipeline and multiplexes 128 analogue output channels on a single analogue output channel which is subsequently digitized by an ADC. A quantitative analysis of data enables the study of potential signal distortion as signal induced global baseline shifts or signal induced cross talk. The combination of two APVs into a pair of master and slave leads to different phases in the transmitted signal which affects the subsequent digitization. Possible signal corrections are deduced and tested for improvement of spatial resolution on experimental data acquired at the Garching Tandem accelerator and the LMU cosmic ray facility.

Low Background Micromegas in CAST

CERN Document Server

Garza, J.G.; Aznar, F.; Calvet, D.; Castel, J.F.; Christensen, F.E.; Dafni, T.; Davenport, M.; Decker, T.; Ferrer-Ribas, E.; Galán, J.; García, J.A.; Giomataris, I.; Hill, R.M.; Iguaz, F.J.; Irastorza, I.G.; Jakobsen, A.C.; Jourde, D.; Mirallas, H.; Ortega, I.; Papaevangelou, T.; Pivovaroff, M.J.; Ruz, J.; Tomás, A.; Vafeiadis, T.; Vogel, J.K.

2015-11-16

Solar axions could be converted into x-rays inside the strong magnetic field of an axion helioscope, triggering the detection of this elusive particle. Low background x-ray detectors are an essential component for the sensitivity of these searches. We report on the latest developments of the Micromegas detectors for the CERN Axion Solar Telescope (CAST), including technological pathfinder activities for the future International Axion Observatory (IAXO). The use of low background techniques and the application of discrimination algorithms based on the high granularity of the readout have led to background levels below 10$^{-6}$ counts/keV/cm$^2$/s, more than a factor 100 lower than the first generation of Micromegas detectors. The best levels achieved at the Canfranc Underground Laboratory (LSC) are as low as 10$^{-7}$ counts/keV/cm$^2$/s, showing good prospects for the application of this technology in IAXO. The current background model, based on underground and surface measurements, is presented, as well as ...

Study of the physical processes involved in the operating mode of the micro-strips gas detector Micromegas

International Nuclear Information System (INIS)

Barouch, G.

2001-04-01

Micromegas is a micro-strip gaseous detector invented in 1996. It consists of two volumes of gas separated by a micro-mesh. The first volume of gas, 3 mm thick, is used to liberate ionization electrons from the incident charged particle. In the second volume, only 100 μm thick, an avalanche phenomenon amplifies the electrons produced in the first volume. Strips printed on an insulating substrate collect the electrons from the avalanche. The geometrical configuration of Micromegas showed many advantages. The short anode-cathode distance combined with a high granularity provide high rate capabilities due to a fast collection of ions produced during the avalanche development. Moreover, the possibility to localize the avalanche with strips printed about every hundreds of micrometers allows to measure the position of the incident particle with a good resolution. In this work, experimental tests of Micromegas are presented along with detailed Monte Carlo simulations used to understand and optimize the detector's performances. The prototypes were tested several times at the PS accelerator at CERN. The analysis of the date showed a stable and efficient behavior of Micromegas combined with an excellent space resolution. In fact, spatial resolutions of less than 15 μm were obtained. In parallel with the in-beam tests, several simulations have been developed in order to gain a better understanding of the detector's response. (author)

High irradiation and ageing properties of resistive Micromegas detectors at the new CERN Gamma Irradiation Facility

CERN Document Server

Andreou, Dimitra

2016-01-01

Resistive Micromegas have been developed in recent years with the aim of making this technology usable in HEP experiments where the high sparking rate of classical Micromegas is not tolerable. A resistive Micromegas with four layers and an active surface of 0.5 m2 each, has been designed and built at CERN as prototype of the detectors to be used for the upgrade of the ATLAS experiment. The detector has been exposed to an intense gamma source of 16 TBq in order to study the effects of ageing and evaluate the detector behavior under high irradiation.

Secondary electrons detectors for beam tracking: micromegas and wire chamber

International Nuclear Information System (INIS)

Pancin, J; Chaminade, T; Drouart, A; Kebbiri, M; Riallot, M; Fernandez, B; Naqvi, F

2009-01-01

SPIRAL2 or FAIR will be able to deliver beams of radioactive isotopes of low energy (less than 10 MeV/n). The emittance of these new beams will impose the use of beam tracking detectors to reconstruct the exact impact position of the nuclei on the experimental target. However, due to their thickness, the classical detectors will generate a lot of energy and angular straggling. A possible alternative is the SED principle (Secondary Electron Detector). It consists of an emissive foil placed in beam and a detector for the secondary electrons ejected by the passing of the nuclei through the foil. An R and D program has been initiated at CEA Saclay to study the possibility to use low pressure gaseous detectors as SED for beam tracking. Some SED have been already used on the VAMOS spectrometer at GANIL since 2004. We have constructed new detectors on this model to measure their performances in time and spatial resolution, and counting rate. Other detector types are also under study. For the first time, a test with different micromegas detectors at 4 Torr has been realized. A comparison on the time resolution has been performed between wire chamber and micromegas at very low pressure. The use of micromegas could be promising to improve the counting rate capability and the robustness of beam tracking detectors.

Performance studies under high irradiation of resistive bulk-micromegas chambers at the CERN Gamma Irradiation Facility

CERN Document Server

Sidiropoulou, Ourania; Bortfeldt, J; Farina, E; Iengo, P; Longo, L; Sidiropoulou, O; Wotschack, J

2017-01-01

Radiation studies on several resistive bulk-Micromegas chambers produced at CERN will be viewed in this document. Two resistive bulk-Micromegas chambers have been installed at the CERN Gamma Irradiation Facility (GIF++) exposed to an intense gamma irradiation with the aim of evaluating the detector behaviour under high irradiation and carrying out a long-term age- ing study. The chambers under study have an active area of 10 x 10 cm 2 , a strip pitch of 400 m m , an ampli- fication gap of 128 m m , and a drift gap of 5 mm. The results on the detector performance as a function of the photon flux up to 44 MHz/cm 2 will be shown as well as the ageing properties as function of the integrated charge and the current intensity and its stability with time. In addition, the results of the efficiency measurements before, during, and after the irradiation will also be presented as a function of the amplification voltage at which the chambers are operated.

Micromesh-selection for the ALTAS New Small Wheel Micromegas detectors

CERN Document Server

Kuger, Fabian; The ATLAS collaboration

2016-01-01

With New Small Wheel Upgrade scheduled for the next long LHC shutdown the innermost end-cap regions of the ATLAS Muon system will be equipped with eight layers of Micromegas detectors. The single quadruplet modules will be up to 2,5m long and 2,2m wide. A key component of a Micromegas are fine conductive meshes, dividing the gas volume into a drift and an amplification region. The selection of the correct mesh is an important design objective, effecting various detector aspects. Among others the electrical field configuration, electron losses during mesh transition and gas flow within the detectors have been studied. Mechanical stability requirements and production process related constrains have been investiaged in close colaboration with industrial partners.

Performance Studies of Micromegas Chambers for the New Small Wheel Upgrade Project

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00349891; The ATLAS collaboration; Leontsinis, Stefanos

2015-01-01

Micromegas, an abbreviation for Micro MEsh Gaseous Structure (MM), is a robust detector with excellent spatial resolution and high rate capability. An $R\\&D$ activity, called Muon ATLAS MicroMegas Activity (MAMMA), was initiated in 2007 in order to explore the potential of the MM technology for use in the ATLAS experiment. After several years of prototyping and testing, the ATLAS collaboration has chosen the MM technology along with the small-strip Thin Gap Chambers (sTGC) for the upgrade of the inner muon station in the high-rapidity region, the so called New Small Wheel (NSW) upgrade project. It will employ eight layers of MM and eight layers of sTGC detectors per wheel. The NSW project requires fully efficient MM chambers, able to cope with the maximum expected rate of $15\\,\\mathrm{kHz/cm^2}$ featuring single plane spatial resolution better than $100\\,\\mu\\mathrm{m}$. The MM detectors will cover a total active area of $\\sim1200\\,\\mathrm{m^2}$ and will be operated in a moderate magnetic field with intens...

Studies of characteristics of triple GEM detector for the ALICE-TPC upgrade

International Nuclear Information System (INIS)

Patra, Rajendra Nath; Singaraju, R.N.; Ahammed, Z.; Nayak, T.K.; Biswas, S.

2015-01-01

Gas Electron Multiplier (GEM) is a novel gas detector in the field of radiation detection. GEM detectors have tremendous advantages over other types gas detectors like high rate handling capability with high efficiency and very low ion back flow (IBF). These detectors are most suitable for the use in the future experiments in high-energy proton-proton and heavy-ion collisions at the Large Hadron Collider (LHC) at CERN and Facility for Antiproton and Ion Research (FAIR) at GSI. A Large Ion Collider Experiment (ALICE) at the LHC is a dedicated experiment for the study of Quark Gluon Plasma (QGP). In few years, the data taking rate for Pb-Pb collisions will increase by 100 times to 50 KHz. The ALICE Time Projection Chamber (TPC) is the main tracking detector in ALICE. It is planned that by the year 2018, GEM detectors will replace the present readout planes of TPC. The goal of the present study is to characterize the GEM detector to achieve the performance goal of the TPC

Neutron Fluence and Energy Reconstruction with the LNE-IRSN/MIMAC Recoil Detector MicroTPC at 27 keV

Energy Technology Data Exchange (ETDEWEB)

Maire, D.; Lebreton, L.; Querre, Ph. [Institute for Radioprotection and Nuclear Safety - IRSN, site of Cadarache, 13115 Saint Paul lez Durance (France); Bosson, G.; Guillaudin, O.; Muraz, J.F.; Riffard, Q.; Santos, D. [Laboratoire de Physique Subatomique et de Cosmologie - LPSCCNRSIN2P3/ UJF/INP, 38000 Grenoble (France)

2015-07-01

The French Institute for Radiation protection and Nuclear Safety (IRSN), designated by the French Metrology Institute (LNE) for neutron metrology, is developing a time projection chamber using a Micromegas anode: microTPC. This work is carried out in collaboration with the Laboratory of Subatomic Physics and Cosmology (LPSC). The aim is to characterize the energy distribution of neutron fluence in the energy range 8 keV - 5 MeV with a primary procedure. The time projection chambers are gaseous detectors able to measure charged particles energy and to reconstruct their track if a pixelated anode is used. In our case, the gas is used as a (n, p) converter in order to detect neutrons down to few keV. Coming from elastic collisions with neutrons, recoil protons lose a part of their kinetic energy by ionizing the gas. The ionization electrons are drifted toward a pixelated anode (2D projection), read at 50 MHz by a self-triggered electronic system to obtain the third track dimension. The neutron energy is reconstructed event by event thanks to proton scattering angle and proton energy measurements. The scattering angle is deduced from the 3D track. The proton energy is obtained by charge collection measurements, knowing the ionization quenching factor (i.e. the part of proton kinetic energy lost by ionizing the gas). The fluence is calculated thanks to the detected events number and the simulation of the detector response. The μTPC is a new reliable detector able to measure energy distribution of the neutron fluence without unfolding procedure or prior neutron calibration contrary to usual gaseous counters. The microTPC is still being developed and measurements have been carried out at the AMANDE facility, with neutrons energies going from 8 keV to 565 keV. After the context and the μ-TPC working principle presentation, measurements of the neutron energy and fluence at 27 keV and 144 keV are shown and compared to the complete detector response simulation. This work

Status of PEP and TPC/2γ

International Nuclear Information System (INIS)

Zapalac, G.

1989-06-01

The TPC/2γ program at PEP has been upgraded by increasing the PEP luminosity and by the adding of a vertex chamber to the TPC detector. These improvements will allow a strong program in B and τ physics, and will contribute to ongoing studies in two-photon physics and hadronization. 10 refs., 3 figs

How to Advance TPC Benchmarks with Dependability Aspects

Science.gov (United States)

Almeida, Raquel; Poess, Meikel; Nambiar, Raghunath; Patil, Indira; Vieira, Marco

Transactional systems are the core of the information systems of most organizations. Although there is general acknowledgement that failures in these systems often entail significant impact both on the proceeds and reputation of companies, the benchmarks developed and managed by the Transaction Processing Performance Council (TPC) still maintain their focus on reporting bare performance. Each TPC benchmark has to pass a list of dependability-related tests (to verify ACID properties), but not all benchmarks require measuring their performances. While TPC-E measures the recovery time of some system failures, TPC-H and TPC-C only require functional correctness of such recovery. Consequently, systems used in TPC benchmarks are tuned mostly for performance. In this paper we argue that nowadays systems should be tuned for a more comprehensive suite of dependability tests, and that a dependability metric should be part of TPC benchmark publications. The paper discusses WHY and HOW this can be achieved. Two approaches are introduced and discussed: augmenting each TPC benchmark in a customized way, by extending each specification individually; and pursuing a more unified approach, defining a generic specification that could be adjoined to any TPC benchmark.

MMSW. A large-size micromegas quadruplet prototype. Reconstruction efficiency and spatial resolution

Energy Technology Data Exchange (ETDEWEB)

Lin, Tai-Hua; Duedder, Andreas; Schott, Matthias; Valderanis, Chrysostomos [Johannes Gutenberg-Universitaet, Mainz (Germany); Bianco, Michele; Danielsson, Hans; Degrange, Jordan; De Oliveira, Rui; Farina, Edoardo; Kuger, Fabian; Iengo, Paolo; Perez Gomez, Francisco; Sekhniaidze, Givi; Sidiropoulou, Ourania; Vergain, Maurice; Wotschack, Joerg [CERN, Geneva (Switzerland)

2016-07-01

One of the upgrades of the ATLAS detector for Run III and beyond is the replacement of the inner part of end cap muon tracking spectrometer with eight layers of resistive micromegas detectors. The performance of two prototype detectors, MMSW (MicroMegas Small Wheel), that adopt the design foreseen for this upgrade was studied. The prototype detectors were tested at the Mainz Microtron for the spatial resolution, with cosmic rays for the reconstruction efficiency and for high rate tests in the new Gamma Irradiation Facility (GIF++) at CERN. These measurements with analysis methods and results will be presented. First performance results are consistent with the ATLAS New Small Wheel requirements.

Micromegas in a bulk

International Nuclear Information System (INIS)

Giomataris, I.; De Oliveira, R.; Andriamonje, S.; Aune, S.; Charpak, G.; Colas, P.; Fanourakis, G.; Ferrer, E.; Giganon, A.; Rebourgeard, Ph.; Salin, P.

2006-01-01

In this paper, we present a novel way to manufacture the bulk Micromegas detector. A simple process based on the Printed Circuit Board (PCB) technology is employed to produce the entire sensitive detector. Such a fabrication process could be extended to very large area detectors made by the industry. The low cost fabrication together with the robustness of the electrode materials will make it attractive for several applications ranging from particle physics and astrophysics to medicine

Investigating the response of Micromegas detector to low-energy neutrons using Monte Carlo simulation

Science.gov (United States)

Khezripour, S.; Negarestani, A.; Rezaie, M. R.

2017-08-01

Micromegas detector has recently been used for high-energy neutron (HEN) detection, but the aim of this research is to investigate the response of the Micromegas detector to low-energy neutron (LEN). For this purpose, a Micromegas detector (with air, P10, BF3, 3He and Ar/BF3 mixture) was optimized for the detection of 60 keV neutrons using the MCNP (Monte Carlo N Particle) code. The simulation results show that the optimum thickness of the cathode is 1 mm and the optimum of microgrid location is 100 μm above the anode. The output current of this detector for Ar (3%) + BF3 (97%) mixture is greater than the other ones. This mixture is considered as the appropriate gas for the Micromegas neutron detector providing the output current for 60 keV neutrons at the level of 97.8 nA per neutron. Consecuently, this detector can be introduced as LEN detector.

A radiation tolerance study of the ALICE TPC Readout Control Unit 2

CERN Document Server

Zhao, Chengxin; Balk, Helge; Alme, Johan

2017-11-17

ALICE is a general-purpose detector that is designed to study the physics of quark-gluon plasma. The Time Projection Chamber (TPC) is one of the major detectors of ALICE. The TPC electronics consists of 4356 Front-end cards (FECs), which are controlled by 216 Readout Control Units (RCU). Each RCU connects to between 18 and 25 FECs using a multi-drop bus. In LHC Run1, the Readout Control Unit 1 (RCU1) performed even better than specification. However, in Run2 the energy of colliding beams is increased from 8 TeV to 14 TeV (maximum value) and higher luminosity, which leads to larger event size and higher radiation load on the electronics. As a solution, the Readout Control Unit 2 (RCU2) is designed to provide faster readout speed and improved radiation tolerance with respect to the RCU1. The RCU2 is conceptually similar to the RCU1 and it reuses the existing infrastructure and readout architecture of the TPC electronics. However, the multi-drop bus is split into four branches from the two branches and the bandw...

Resistive Micromegas for the Muon Spectrometer Upgrade of the ATLAS Experiment

CERN Document Server

Iodice, Mauro; The ATLAS collaboration

2016-01-01

Large size resistive Micromegas detectors will be employed for the first time in high-energy physics experiments for the Muon Spectrometer upgrade of the ATLAS experiment at CERN. The current innermost stations of the muon endcap system, the Small Wheel, will be upgraded in 2019 to retain the good precision tracking and trigger capabilities in the high background environment expected with the upcoming luminosity increase of the LHC. Along with the small-strip Thin Gap Chambers (sTGC) the “New Small Wheel” will be equipped with eight layers of Micromegas (MM) detectors arranged in multilayers of two quadruplets, for a total of about 1200 m$^2$ detection planes. All quadruplets have trapezoidal shapes with surface areas between 2 and 3 m$^2$. The Micromegas system will provide both trigger and tracking capabilities. In order to achieve a 15% transverse momentum resolution for 1 TeV muons, a challenging mechanical precision is required in the construction for each plane of the assembled modules, with an alig...

CAMAC interface for TPC data-acquisition electronics

International Nuclear Information System (INIS)

Sidman, S.; Olson, S.; Jared, R.

1983-06-01

The Time Projection Chamber (TPC) is a detector used for high-energy physics research at the Stanford PEP Accelerator. TPC requires about 17,000 channels of data acquisition, which samples on command the input to each channel at a 10 MHz rate. This high data rate is made possible by means of Charge Coupled Devices (CCDs), intelligent digitizers, and a sophisticated trigger system. The TPC-CAMAC interface described here was developed to allow experiments of smaller scale than the complete TPC to use the standard data acquisition portion of the TPC electronics, namely the amplifier, CCD and digitizer bins. These three bins, when properly interconnected and controlled by the interface control bin, form a transient digitizer with a depth of 455 samples and a maximum width of 256 channels per bin set

Performance and applications of a μ-TPC

International Nuclear Information System (INIS)

Miuchi, Kentaro; Kubo, Hidetoshi; Nagayoshi, Tsutomu; Okada, Yoko; Orito, Reiko; Takada, Atsushi; Takeda, Atsushi; Tanimori, Toru; Ueno, Masaru; Bouianov, Oleg; Bouianov, Marina

2004-01-01

A μ-TPC, a time projection chamber (TPC) which can detect three-dimensional fine tracks of charged particles, was developed and its performance was measured. We developed a μ-TPC with a detection volume of 10x10x10cm3 based on a novel two-dimensional imaging gaseous detector, or the μ-PIC. Fine tracks of charged particles with large energy depositions (protons and electrons) were detected with the μ-TPC. With a pressurized gas, tracks of the minimum ionizing particles were detected. We showed the principle of the application for the time-resolved neutron imaging detector

Simulation of micromegas detector by Garfield program

International Nuclear Information System (INIS)

Zhang Xiaodong; Zhang Yi; Yang Herun; Xu Hushan; Duan Limin; Li Chunyan; Li Zuyu

2007-01-01

In this paper, a batch file which describes the detailed structure and the corresponding physical process of Micro-Mesh Gaseous Structure (Micromegas) detector, the macro commands and the control structures based on the Garfield program has been developed. And using the Garfield program controlled by this batch file, the detector's gain and spatial resolution have been investigated under different conditions. These results obtained by the simulation program not only exhibit the influences of the mesh and drift voltage, the mixture gas proportion, the distance between the mesh cathode and the printed circuit board readout anode, and the Lines Per Inch of the mesh cathode on the gain and spatial resolution of the detector, but also are very important to optimize the design, shorten the experimental period, and save cost during the detector development. Additionally, they also indicate that the Garfield program is a powerful tool for the Micromegas detector design and optimization. (authors)

Ageing studies of resistive Micromegas detectors for the HL-LHC

CERN Document Server

Galán, J; Ferrer-Ribas, E; Giganon, A; Giomataris, I; Herlant, S; Jeanneau, F; Peyaud, A; Schune, Ph; Alexopoulos, T; Byszewski, M; Iakovidis, G; Iengo, P; Ntekas, K; Leontsinis, S; de Oliveira, R; Tsipolitis, Y; Wotschack, J

2013-01-01

Resistive-anode Micromegas detectors are in development since several years, in an effort to solve the problem of sparks when working in high flux and high radiations environment like in the HL-LHC (ten times the luminosity of the LHC). They have been chosen as one of the technologies that will be part of the ATLAS New Small Wheel project (forward muon system). An ageing study is mandatory to assess their capabilities to handle the HL-LHC environment on a long-term period. A prototype has been exposed to several types of irradiations (X-rays, cold neutrons, 60 Co gammas) up to an equivalent HL-LHC time of more than five years without showing any degradation of the performances in terms of gain and energy resolution. Beam test studies took place in October 2012 to assess the tracking performances (efficiency, spatial resolution,...). Results of ageing studies and beam test performances are reported in this paper.

New neutron detector based on micromegas technology for ADS projects

International Nuclear Information System (INIS)

Andriamonje, Samuel; Andriamonje, Gregory; Aune, Stephan; Ban, Gilles; Breaud, Stephane; Blandin, Christophe; Ferrer, Esther; Geslot, Benoit; Giganon, Arnaud; Giomataris, Ioannis; Jammes, Christian; Kadi, Yacine; Laborie, Philippe; Lecolley, Jean Francois; Pancin, Julien; Riallot, Marc; Rosa, Roberto; Sarchiapone, Lucia; Steckmeyer, Jean Claude; Tillier, Joel

2006-01-01

A new neutron detector based on Micromegas technology has been developed for the measurement of the simulated neutron spectrum in the ADS project. After the presentation of simulated neutron spectra obtained in the interaction of 140 MeV protons with the spallation target inside the TRIGA core, a full description of the new detector configuration is given. The advantage of this detector compared to conventional neutron flux detectors and the results obtained with the first prototype at the CELINA 14 MeV neutron source facility at CEA-Cadarache are presented. The future developments of operational Piccolo-Micromegas for fast neutron reactors are also described

New neutron detector based on micromegas technology for ADS projects

Energy Technology Data Exchange (ETDEWEB)

Andriamonje, Samuel [CEA-Saclay, DSM/DAPNIA, F-91191 Gif-sur-Yvette (France)]. E-mail: sandriamonje@cea.fr; Andriamonje, Gregory [IXL-Universite Bordeaux 1-BAT. A31-351 cours de la Liberation-F-33405 Talence Cedex (France); Aune, Stephan [CEA-Saclay, DSM/DAPNIA, F-91191 Gif-sur-Yvette (France); Ban, Gilles [CNRS/IN2P3 LPC Caen, 6 Boulevard Marechal Juin, F-14050 Caen Cedex (France); Breaud, Stephane [CEA/DEN/Cadarache, 13108 Saint-Paul Lez Durance (France); Blandin, Christophe [CEA/DEN/Cadarache, 13108 Saint-Paul Lez Durance (France); Ferrer, Esther [CEA-Saclay, DSM/DAPNIA, F-91191 Gif-sur-Yvette (France); Geslot, Benoit [CEA/DEN/Cadarache, 13108 Saint-Paul Lez Durance (France); Giganon, Arnaud [CEA-Saclay, DSM/DAPNIA, F-91191 Gif-sur-Yvette (France); Giomataris, Ioannis [CEA-Saclay, DSM/DAPNIA, F-91191 Gif-sur-Yvette (France); Jammes, Christian [CEA/DEN/Cadarache, 13108 Saint-Paul Lez Durance (France); Kadi, Yacine [CERN CH 1211 Geneva (Switzerland); Laborie, Philippe [CNRS/IN2P3 LPC Caen, 6 Boulevard Marechal Juin, F-14050 Caen Cedex (France); Lecolley, Jean Francois [CNRS/IN2P3 LPC Caen, 6 Boulevard Marechal Juin, F-14050 Caen Cedex (France); Pancin, Julien [CEA-Saclay, DSM/DAPNIA, F-91191 Gif-sur-Yvette (France); Riallot, Marc [CEA-Saclay, DSM/DAPNIA, F-91191 Gif-sur-Yvette (France); Rosa, Roberto [ENEA-Casaccia, Via Anguillarese, 00060 Rome (Italy); Sarchiapone, Lucia [CERN CH 1211 Geneva (Switzerland); Steckmeyer, Jean Claude [CNRS/IN2P3 LPC Caen, 6 Boulevard Marechal Juin, F-14050 Caen Cedex (France); Tillier, Joel [CNRS/IN2P3 LPC Caen, 6 Boulevard Marechal Juin, F-14050 Caen Cedex (France)

2006-06-23

A new neutron detector based on Micromegas technology has been developed for the measurement of the simulated neutron spectrum in the ADS project. After the presentation of simulated neutron spectra obtained in the interaction of 140 MeV protons with the spallation target inside the TRIGA core, a full description of the new detector configuration is given. The advantage of this detector compared to conventional neutron flux detectors and the results obtained with the first prototype at the CELINA 14 MeV neutron source facility at CEA-Cadarache are presented. The future developments of operational Piccolo-Micromegas for fast neutron reactors are also described.

Construction and performance studies of large resistive Micromegas quadruplets

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00508881; Iengo, Paolo; Bianco, Michele; Sidiropoulou, Ourania; Kuger, Fabian; Sekhniaidze, Givi; Wotschack, Jorg; Vergain, Maurice; Danielsson, Hans Olof; Degrange, Jordan; Schott, Matthias; Lin, Tai-Hua; Valderanis, Chrysostomos; Dudder, Andreas Christian

2015-01-01

In view of the use of Micromegas detectors for the upgrade of the ATLAS muon system, two detector quadruplets with an area of 0.3 m$^2$ per plane serving as prototypes for future ATLAS chambers have been constructed. They are based on the resistive-strip technology and thus spark tolerant. The detectors were built in a modular way. The quadruplets consist of two double-sided readout panels and three support (or drift) panels equipped with the micromesh and the drift electrode. The panels are bolted together such that the detector can be opened and cleaned, if required. Two of the readout planes are equipped with readout strips inclined by 1.5 degree. In this talk, we present the results of detailed performance studies based on X-Ray and cosmic ray measurements as well as measurements with 855 MeV electrons at the MAMI accelerator. In particular, results on reconstruction efficiencies, track resolution and gain homogeneity is presented.

Construction and Performance Studies of Large Resistive Micromegas Quadruplets

CERN Document Server

Farina, Edoardo Maria; The ATLAS collaboration; Kuger, Fabian; Sidiropoulou, Ourania; Iengo, Paolo; Sekhniaidze, Givi; Wotschack, Jorg; Lin, Tai-Hua; Schott, Matthias; Valderanis, Chrysostomos; Dudder, Andreas Christian

2015-01-01

In view of the use of micromegas detectors for the upgrade of the ATLAS muon system, two detector quadruplets with an area of 0.5 m2 per plane serving as prototypes for future ATLAS chambers have been constructed. They are based on the resistive-strip technology and thus spark tolerant. The detectors were built in a modular way. The quadruplets consist of two double-sided readout panels and three support (or drift) panels equipped with the micromesh and the drift electrode. The panels are bolted together such that the detector can be opened and cleaned, if required. Two of the readout planes are equipped with readout strips inclined by 1.5 degree. In this talk, we present the results of detailed performance studies based on X-Ray measurements, cosmic ray- and test-beam measurements at the MAMI accelerator that have been conducted in the past months. In particular, results on reconstruction efficiencies, track resolution and gain homogeneity will be presented.

Construction and Performance Studies of Large Resistive Micromegas Quadruplets

Science.gov (United States)

Farina, E.; Iengo, P.; Bianco, M.; Sidiropoulou, O.; Kuger, F.; Sekhniaidze, G.; Vergain, M.; Wotschack, J.; Danielsson, H.; Degrange, J.; De Oliveira, R.; Schott, M.; Lin, Tai-Hua; Valderanis, C.; Düdder, A.

2018-02-01

In view of the use of Micromegas detectors for the upgrade of the ATLAS muon system, two detector quadruplets with an area of 0.3 m2 per plane serving as prototypes for future ATLAS chambers have been constructed. They are based on the resistive-strip technology and thus spark tolerant. The detectors were built in a modular way. The quadruplets consist of two double-sided readout panels and three support (or drift) panels equipped with the micromesh and the drift electrode. The panels are bolted together such that the detector can be opened and cleaned, if required. Two of the readout planes are equipped with readout strips inclined by 1.5 degree. In this talk, we present the results of detailed performance studies based on X-Ray and cosmic ray measurements as well as measurements with 855 MeV electrons at the MAMI accelerator. In particular, results on reconstruction efficiencies, track resolution and gain homogeneity is presented.

Micromegas Detectors for the Muon Spectrometer Upgrade of the ATLAS Experiment

CERN Document Server

Iodice, Mauro; The ATLAS collaboration

2015-01-01

The Micromegas (MICRO MEsh GAseous Structure) have been proven along the years to be reliable detectors with excellent space resolution and high rate capability. Large area Micromegas will be employed for the first time in high-energy physics for the Muon Spectrometer upgrade of the ATLAS experiment at CERN LHC. A total surface of about 150 m$^2$ of the forward regions of the Muon Spectrometer will be equipped with 8 layers of Micromegas modules. Each module covers a surface from 2 to 3 m$^2$ for a total active area of 1200 m$^2$. Together with the small-strips Thin Gap Chambers, they will compose the two New Small Wheels, which will replace the innermost stations of the ATLAS Endcap Muon tracking system in the 2018/19 shutdown. The breakthroughs and developments of this type of Micro Pattern Gas Detector will be reviewed, along with the path towards the construction of the modules, which will take place in several production sites starting in 2015. An overview of the detector performances obtained in the rec...

Micromegas Detectors for the Muon Spectrometer Upgrade of the ATLAS Experiment

CERN Document Server

Iodice, M; The ATLAS collaboration

2014-01-01

The Micromegas (MICRO MEsh GAseous Structure) chambers have been proven along the years to be reliable detectors with excellent space resolution and high rate capability. Large area Micromegas will be employed for the first time in high-energy physics for the Muon Spectrometer upgrade of the ATLAS experiment at CERN LHC. A total surface of about 150 m2 of the forward regions of the Muon Spectrometer will be equipped with 8 layers of Micromegas modules. Each module covers a surface from 2 to 3 m2 for a total active area of 1200 m2. Together with the small-strips Thin Gap Chambers, they will compose the two New Small Wheels, which will replace the innermost stations of the ATLAS Endcap Muon tracking system in the 2018/19 shutdown. The principles of operation and recent developments of this type of Micro Pattern Gas Detector will be reviewed, along with our plans towards the construction of the modules, which will take place in several production sites. An overview of the detector performances obtained in the re...

Performance studies under high irradiation and ageing properties of resistive bulk Micromegas chambers at the new CERN Gamma Irradiation Facility

International Nuclear Information System (INIS)

Sidiropoulou, O.; Gonzalez, B. Alvarez; Bianco, M.; Farina, E.M.; Iengo, P.; Longo, L.; Pfeiffer, D.; Wotschack, J.

2017-01-01

Resistive bulk Micromegas chambers, produced at CERN, have been installed at the new CERN Gamma Irradiation Facility (GIF++) in order to study the effects of ageing and to evaluate the detector behaviour under high irradiation. The chambers have an active area of 10×10 cm 2 , strip pitch of 400 μm and an amplification gap of 128 μm. We present the detector performance as a function of the background rate of up to 20 MHz/cm 2 . - Highlights: • Small-size resistive bulk Micromegas detectors have been exposed to the new GIF++. • 9 months irradiation to γ up to 20 Mhz/cm 2 . 0.09 C/cm 2 collected integrated charge. • Νo degradation of the detector performance was observed. • Muon tracks successfully reconstructed up to 68 kHz/cm 2 gamma background. • Higher background rates will be studied in the coming months.

Spatial resolution in Micromegas detectors

CERN Document Server

Bayb, A; Giomataris, Ioanis; Zaccone, Henri; Bay, A; Perroud, Jean-Pierre; Ronga, F

2001-01-01

The performance of a telescope of Micromegas detectors has been studied in a pion beam at the CERN PS. With a gas filling of CF/sub 4 / and 20% isobutane and with a strip pitch of 100 mu m an accuracy of 14+or-3 mu m on the spatial resolution has been measured at normal incidence. A simulation demonstrates that the resolution is limited by the size of the holes of the mesh of the detector and could be reduced to 11 mu m in the same conditions with smaller holes. Even further improvement down to 8.5 mu m is feasible for the same gas with an optimized 75 mu m strip pitch. (5 refs).

TPC track distortions III: fiat lux

CERN Document Server

Boyko, I; Dydak, F; Elagin, A; Gostkin, M; Guskov, A; Koreshev, V; Nefedov, Y; Nikolaev, K; Veenhof, R; Wotschack, J; Zhemchugov, A

2005-01-01

We present a comprehensive overview and final summary of all four types of static track distortions seen in the HARP TPC, in terms of physical origins, mathematical modelling, and correction algorithms. 'Static'™ distortions are defined as not depending on the event time within the 400 ms long accelerator spill. Calculated static distortions are compared with measurements from cosmic-muon tracks. We characterize track distortions by the r phi residuals of cluster positions with respect to the transverse projection of a helical trajectory constrained by hits in the RPC overlap regions. This method provides a fixed TPC-external reference system (by contrast to the co-moving coordinate system associated with a fit) which solely permits to identify individually, and measure quantitatively, the static TPC track distortions arising from (i) the inhomogeneity of the solenoidal magnetic field, (ii) the inhomogeneity of the electric field from the high-voltage mismatch between the inner and outer TPC field cages, (...

Compression of TPC data in the ALICE experiment

International Nuclear Information System (INIS)

Nicolaucig, A.; Mattavelli, M.; Carrato, S.

2002-01-01

In this paper two algorithms for the compression of the data generated by the Time Projection Chamber (TPC) detector of the ALICE experiment at CERN are described. The first algorithm is based on a lossless source code modeling technique, i.e. the original TPC signal information can be reconstructed without errors at the decompression stage. The source model exploits the temporal correlation that is present in the TPC data to reduce the entropy of the source. The second algorithm is based on a source model which is lossy if samples of the TPC signal are considered one by one. Conversely, the source model is lossless or quasi-lossless if some physical quantities that are of main interest for the experiment are considered. These quantities are the area and the location of the center of mass of each TPC signal pulse. Obviously entropy coding is applied to the set of events defined by the two source models to reduce the bit rate to the corresponding source entropy. Using TPC simulated data according to the expected ALICE TPC performance, the lossless and the lossy compression algorithms achieve a data reduction, respectively, to 49.2% and in the range of 34.2% down to 23.7% of the original data rate. The number of operations per input symbol required to implement the compression stage for both algorithms is relatively low, so that a real-time implementation embedded in the TPC data acquisition chain using low-cost integrated electronics is a realistic option to effectively reduce the data storing cost of ALICE experiment

A UV sensitive integrated micromegas with timepix readout

NARCIS (Netherlands)

Melai, J.; Breskin, Amos; Cortesi, Marco; Bilevych, Y.; Bilevych, Yevgen; Fransen, Martin; van der Graaf, Harry; Visschers, Jan; Blanco Carballo, V.M.; Salm, Cora; Schmitz, Jurriaan

2010-01-01

This article presents a detector system consisting of three components, a CMOS imaging array, a gaseous-detector structure with a Micromegas layout, and a UV-photon sensitive CsI reflective photocathode. All three elements have been monolithically integrated using simple post-processing steps. The

Development of large size Micromegas detectors for the upgrade of the ATLAS experiments

CERN Document Server

Bianco, Michele

2014-01-01

The luminosity upgrade of the Large Hadron Collider at CERN f oresees a luminosity increase by a factor 3 compared to the LHC luminosity design value. To c ope with the corresponding rate increase, the Muon System of the ATLAS experiment at CER N needs to be upgraded. In the first station of the high rapidity region, micromegas det ectors have been chosen as the main tracking chambers but will, at the same time, also contribut e to the trigger. We describe the R&D; efforts that led to the construction of the first (1 × 2.4 m 2 ) large micromegas detectors at CERN and outline the next steps towards the construction of the 12 00 m 2 of micromegas detectors for the ATLAS upgrade. The technical solutions, adopted in the c onstruction of the chamber as well as results on the detector performance with cosmic rays are s hown.

Cryogenic testing of the TPC superconducting solenoid

International Nuclear Information System (INIS)

Green, M.A.; Smits, R.G.; Taylor, J.D.

1983-06-01

This report describes the results of a series of tests on the TPC superconducting magnet cryogenic system which occurred during the winter and spring of 1983. The tests occurred at interaction region 2 of the PEP colliding beam facility at the Stanford Linear Accelerator Center (SLAC). The TPC Magnet Cryogenic System which was tested includes the following major components: a remote helium compressor with a full flow liquid nitrogen purification station, 400 meters of high pressure supply and low pressure return lines; and locally a CTi Model 2800 refrigerator with two Sulzer gas bearing turbines, the TPC magnet control dewar, 70 meters of transfer lines, and the TPC thin superconducting solenoid magnet. In addition, there is a conditioner (liquid nitrogen heat exchangers and gas heaters) system for cooldown and warmup of the magnet. This report describes the local cryogenic system and describes the various steps in the cooldown and operation of the TPC magnet. The tests were successful in that they showed that the TPC magnet could be cooled down in 24 hours and the magnet could be operated on the refrigerator or a helium pump with adequate cooling margin. The tests identified problems with the cryogenic system and the 2800 refrigerator. Procedures for successful operation and quenching of the superconducting magnet were developed. 19 references

Optimized iterative decoding method for TPC coded CPM

Science.gov (United States)

Ma, Yanmin; Lai, Penghui; Wang, Shilian; Xie, Shunqin; Zhang, Wei

2018-05-01

Turbo Product Code (TPC) coded Continuous Phase Modulation (CPM) system (TPC-CPM) has been widely used in aeronautical telemetry and satellite communication. This paper mainly investigates the improvement and optimization on the TPC-CPM system. We first add the interleaver and deinterleaver to the TPC-CPM system, and then establish an iterative system to iteratively decode. However, the improved system has a poor convergence ability. To overcome this issue, we use the Extrinsic Information Transfer (EXIT) analysis to find the optimal factors for the system. The experiments show our method is efficient to improve the convergence performance.

Test in a beam of large-area Micromegas chambers for sampling calorimetry

CERN Document Server

Adloff, C.; Dalmaz, A.; Drancourt, C.; Gaglione, R.; Geffroy, N.; Jacquemier, J.; Karyotakis, Y.; Koletsou, I.; Peltier, F.; Samarati, J.; Vouters, G.

2014-06-11

Application of Micromegas for sampling calorimetry puts specific constraints on the design and performance of this gaseous detector. In particular, uniform and linear response, low noise and stability against high ionisation density deposits are prerequisites to achieving good energy resolution. A Micromegas-based hadronic calorimeter was proposed for an application at a future linear collider experiment and three technologically advanced prototypes of 1$\\times$1 m$^{2}$ were constructed. Their merits relative to the above-mentioned criteria are discussed on the basis of measurements performed at the CERN SPS test-beam facility.

Performance Studies of a Micromegas Chamber in the ATLAS Environment

CERN Document Server

Kataoka, Y; Ntekas, K

2014-01-01

Five small prototype micromegas detectors were positioned in the ATLAS detector during Large Hadron Collider running at $\\sqrt{s} = 7$ and $8\\, \\mathrm{TeV}$. A $9\\times 4.5\\, \\mathrm{cm^2}$ two-gap detector was placed in front of the electromagnetic calorimeter and four $9\\times 10\\, \\mathrm{cm^2}$ detectors on the ATLAS Small Wheel, the first station of the forward muon spectrometer. The one attached to the calorimeter was exposed to interaction rates of about $70\\,\\mathrm{kHz}$ at $\\mathcal{L}=5\\times 10^{33}\\,\\mathrm{cm^{-2}s^{-1}}$ two orders of magnitude higher than the rates in the Small Wheel. We present the results from performance studies carried out using data collected with these detectors and we also compare the currents drawn by the detector installed in front of the electromagnetic calorimeter with the luminosity measurement in ATLAS.

The ALICE TPC

CERN Document Server

Garabatos, C

2004-01-01

We describe the ALICE TPC, with emphasis on the design features which are driven by the physics requirements of the detector. In particular, the gas choice and composition, Ne-CO/sub 2/ Ý90-10¿, as well as the unprecedentedly high gain for a TPC (2*10/sup 40/), are direct consequences of the expected performance in the high- multiplicity environment of heavy-ion collisions at the LHC. The characteristics of this mixture are discussed and a viable way of improving the stability of detectors working under these conditions, namely the addition of nitrogen into the mixture, is presented. This results in a more effective Penning transfer of neon excited states onto ionisation of the quencher at no penalty for the charge transport and amplification properties.

Development of large area resistive electrodes for ATLAS NSW MicroMEGAS

CERN Document Server

Ochi, Atsuhiko; The ATLAS collaboration

2015-01-01

MicroMegas with resistive anode will be used for the NSW upgrade of the ATLAS experiment at LHC. The resistive electrode is one of key technology for MPGDs to prevent sparks. Large area resistive electrodes for the MM have been developed using two different technology; screen printing and carbon sputtering. Maximum size of each resistive foil is 45cm x 220cm with printed pattern of 425 micron pitch strips. Those technologies are also suitable to mass production. The prototypes of series production model have been produced successfully. We will report the development and production status and test results of the resistive MicroMegas.

A laser calibration system for the STAR TPC

CERN Document Server

Lebedev, A

2002-01-01

A Time Projection Chamber (TPC) is the primary tracking detector for the STAR experiment at RHIC. A laser calibration system was built to calibrate and monitor the TPC tracking performance. The laser system uses a novel design which produces approx 500 thin, ionizing beams distributed throughout the tracking volume. This new approach is significantly simpler than the traditional ones, and provides complete TPC coverage at a reduced cost. The laser system was used during the RHIC 2000 summer run to measure drift velocities with about 0.02% accuracy and to monitor the TPC performance. Calibration runs were made with and without a magnetic field to check B field map corrections.

Neutron fluence and energy reconstruction with the IRSN recoil detector μ-TPC at 27 keV, 144 keV and 565 keV

Energy Technology Data Exchange (ETDEWEB)

Maire, D.; Lebreton, L.; Richer, J.P. [IRSN, PRP-HOM, SDE, LMDN, 13115 Saint Paul-Lez-Durance (France); Bosson, G.; Bourrion, O.; Guillaudin, O.; Riffard, Q.; Santos, D. [CNRS/IN2P3-UJF-INPG, LPSC, 38000 Grenoble (France)

2015-07-01

The French Institute for Radioprotection and Nuclear Safety (IRSN), associated to the French Metrology Institute (LNE), is developing a time projection chamber using a Micromegas anode: μ-TPC. This work is carried out in collaboration with the Laboratory of Subatomic Physics and Cosmology (LPSC). The aim is to characterize with a primary procedure the energy distribution of neutron fluence in the energy range 8 keV - 1 MeV. The time projection chambers are gaseous detectors, which are able to measure charged particles energy and to reconstruct their track if a pixelated anode is used. In our case, the gas is used as a (n, p) converter in order to detect neutrons down to few keV. Coming from elastic collisions with neutrons, recoil protons lose a part of their kinetic energy by ionizing the gas. The ionization electrons are drifted toward a pixelated anode (2D projection), read at 50 MHz by a self-triggered electronic system to obtain the third track dimension. The neutron energy is reconstructed event by event thanks to proton scattering angle and proton energy measurements. The scattering angle is deduced from the 3D track. The proton energy is obtained by charge collection measurements, knowing the ionization quenching factor (i.e. the part of proton kinetic energy lost by ionizing the gas). The fluence is calculated thanks to the detected events number and the simulated detector response. The μ-TPC is a new reliable detector which enables to measure energy distribution of the neutron fluence without deconvolution or neutron calibration contrary to usual gaseous counters. The μ-TPC is still being developed and measurements have been carried out at the AMANDE facility, with neutrons energies going from 8 keV to 565 keV. After the context and the μ-TPC working principle presentation, measurements of the neutron energy and fluence at 27.2 keV, 144 keV and 565 keV are shown and compared to the complete detector simulation. This work shows the first direct

The Micromegas detector of the CAST experiment

International Nuclear Information System (INIS)

Abbon, P; Andriamonje, S; Aune, S; Dafni, T; Davenport, M; Delagnes, E; Oliveira, R de; Fanourakis, G; Ribas, E Ferrer; Franz, J; Geralis, T; Giganon, A; Gros, M; Giomataris, Y; Irastorza, I G; Kousouris, K; Morales, J; Papaevangelou, T; Ruz, J; Zachariadou, K; Zioutas, K

2007-01-01

A low-background Micromegas detector has been operating in the CAST experiment at CERN for the search for solar axions during the first phase of the experiment (2002-2004). The detector, made out of low radioactivity materials, operated efficiently and achieved a very high level of background rejection (5 x 10 -5 counts keV -1 cm -2 s -1 ) without shielding

Characterization and Calibration of Large Area Resistive Strip Micromegas Detectors

CERN Document Server

Losel, Philipp Jonathan; The ATLAS collaboration

2015-01-01

Resisitve strip Micromegas detectors behave discharge tolerant. They have been tested extensively as smaller detectors of about 10 x 10 cm$^2$ in size and they work reliably at high rates of 100\\,kHz/cm$^2$ and above. Tracking resolutions well below 100\\,$\\mu$m have been observed for 100 GeV muons and pions. Micromegas detectors are meanwhile proposed as large area muon precision trackers of 2-3\\,m$^2$ in size. To investigate possible differences between small and large detectors, a 1\\,m$^2$ detector with 2048 resistive strips at a pitch of 450 $\\mu$m was studied in the LMU Cosmic Ray Facility (CRF) using two 4 $\\times$ 2.2 m$^2$ large Monitored Drift Tube (MDT) chambers for cosmic muon reference tracking. Segmentation of the resistive strip anode plane in 57.6\\,mm x 95\\,mm large areas has been realized by the readout of 128 strips with one APV25 chip each and by 11 95\\,mm broad trigger scintillators placed along the readout strips.\\\\ This allows for mapping of homogenity in pulse height and efficiency, deter...

MICROMEGAS chambers for hadronic calorimetry at a future linear collider

CERN Document Server

Adloff, C.; Blaha, J.; Cap, S.; Chefdeville, M.; Colas, P.; Dalmaz, A.; Drancourt, C.; Espargiliere, A.; Gaglione, R.; Gallet, R.; Geffroy, N.; Giomataris, I.; Jaquemier, J.; Karyotakis, Y.; Peltier, F.; Prast, J.; Vouters, G.

2009-01-01

Prototypes of MICROMEGAS chambers, using bulk technology and analog readout, with 1x1cm2 readout segmentation have been built and tested. Measurements in Ar/iC4H10 (95/5) and Ar/CO2 (80/20) are reported. The dependency of the prototypes gas gain versus pressure, gas temperature and amplification gap thickness variations has been measured with an 55Fe source and a method for temperature and pressure correction of data is presented. A stack of four chambers has been tested in 200GeV/c and 7GeV/c muon and pion beams respectively. Measurements of response uniformity, detection efficiency and hit multiplicity are reported. A bulk MICROMEGAS prototype with embedded digital readout electronics has been assembled and tested. The chamber layout and first results are presented.

MMSW. A large-size micromegas quadruplet prototype. Design and construction

Energy Technology Data Exchange (ETDEWEB)

Kuger, Fabian; Sidiropoulou, Ourania [Julius Maximilians Universitaet, Wuerzburg (Germany); European Organization for Nuclear Research (CERN), Geneva (Switzerland); Bianco, Michele; Danielsson, Hans; Degrange, Jordan; Oliveira, Rui de; Farina, Eduardo; Iengo, Paolo; Perez Gomez, Francisco; Sekhniaidze, Givi; Sforza, Federico; Vergain, Maurice; Wotschack, Joerg [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Duedder, Andreas; Lin, Tai-Hua; Schott, Matthias [Johannes Gutenberg-Universitaet, Mainz (Germany)

2016-07-01

Two micromegas detector quadruplets with an area of 0.5 m{sup 2} (MMSW) have been recently constructed and tested at CERN and University of Mainz. They serve as prototypes for the planned upgrade project of the ATLAS muon system. Their design is based on the resistive-strip technology and thus renders the detectors spark tolerant. The applied 'mechanically floating' mesh design allows for large area Micromegas construction and facilitates detector cleaning before assembly. Each quadruplet comprises four detection layers with 1024 readout strips and a strip pitch of 415 μm. In two out of the four layers the strips are inclined by ± 1.5 to allow for the measurement of a second coordinate. We present the detector concept and report on the experience gained during the detector construction.

Signal Formation Processes in Micromegas Detectors and Quality Control for large size Detector Construction for the ATLAS New Small Wheel

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00387450; Rembser, Christoph

2017-08-04

The Micromegas technology is one of the most successful modern gaseous detector concepts and widely utilized in nuclear and particle physics experiments. Twenty years of R & D rendered the technology sufficiently mature to be selected as precision tracking detector for the New Small Wheel (NSW) upgrade of the ATLAS Muon spectrometer. This will be the first large scale application of Micromegas in one of the major LHC experiments. However, many of the fundamental microscopic processes in these gaseous detectors are still not fully understood and studies on several detector aspects, like the micromesh geometry, have never been addressed systematically. The studies on signal formation in Micromegas, presented in the first part of this thesis, focuses on the microscopic signal electron loss mechanisms and the amplification processes in electron gas interaction. Based on a detailed model of detector parameter dependencies, these processes are scrutinized in an iterating comparison between exper- imental result...

Design, construction and quality control of resistive-Micromegas anode boards for the ATLAS experiment

Science.gov (United States)

Kuger, F.; Iengo, P.

2018-02-01

For the upcoming upgrade of the forward muon stations of the ATLAS detector, 1280m2 of Micromegas chambers have to be constructed. The industrialization of anode board production is an essential precondition. Design and construction methods of these boards have been optimized towards mass production. In parallel quality control procedures have been developed and established. The first set of large size Micromegas anode boards has finally been produced in industries and demonstrates the feasibility of the project on full-scale.

ALICE Time Projection Chamber (TPC) Readout Sector in Lab

CERN Multimedia

2003-01-01

The Time Projection Chamber (TPC) is the main particle tracking detector in ALICE. Charged particles crossing the gas of the TPC knock electrons out of their atoms, which drift in the eletric field. By measuring the arrival of electrons at the end of the chamber, at segments such as the one shown here, the TPC will reconstruct the paths of the original charged particles.

Study of electron recombination in liquid argon with the ICARUS TPC

International Nuclear Information System (INIS)

Amoruso, S.; Antonello, M.; Aprili, P.; Arneodo, F.; Badertscher, A.; Baiboussinov, B.; Baldo Ceolin, M.; Battistoni, G.; Bekman, B.; Benetti, P.; Bischofberger, M.; Borio di Tigliole, A.; Brunetti, R.; Bruzzese, R.; Bueno, A.; Buzzanca, M.; Calligarich, E.; Campanelli, M.; Carbonara, F.; Carpanese, C.; Cavalli, D.; Cavanna, F.; Cennini, P.; Centro, S.; Cesana, A.; Chen, C.; Chen, D.; Chen, D.B.; Chen, Y.; Cieslik, K.; Cline, D.; Cocco, A.G.; Dai, Z.; De Vecchi, C.; Dabrowska, A.; Di Cicco, A.; Dolfini, R.; Ereditato, A.; Felcini, M.; Ferrari, A.; Ferri, F.; Fiorillo, G.; Galli, S.; Ge, Y.; Gibin, D.; Gigli Berzolari, A.; Gil-Botella, I.; Graczyk, K.; Grandi, L.; Guglielmi, A.; He, K.; Holeczek, J.; Huang, X.; Juszczak, C.; Kielczewska, D.; Kisiel, J.; Kozlowski, T.; Laffranchi, M.; Lagoda, J.; Li, Z.; Lu, F.; Ma, J.; Mangano, G.; Markiewicz, M.; Martinez de la Ossa, A.; Matthey, C.; Mauri, F.; Meng, G.; Messina, M.; Montanari, C.; Muraro, S.; Navas-Concha, S.; Otwinowski, S.; Ouyang, Q.; Palamara, O.; Pascoli, D.; Periale, L.; Piano Mortari, G.B.; Piazzoli, A.; Picchi, P.; Pietropaolo, F.; Polopek, W.; Rancati, T.; Rappoldi, A.; Raselli, G.L.; Rico, J.; Rondio, E.; Rossella, M.; Rubbia, A.; Rubbia, C.; Sala, P.R.; Santorelli, R.; Scannicchio, D.; Segreto, E.; Seo, Y.; Sergiampietri, F.; Sobczyk, J.; Spinelli, N.; Stepaniak, J.; Sulej, R.; Szarska, M.; Szeptycka, M.; Terrani, M.; Velotta, R.; Ventura, S.; Vignoli, C.; Wang, H.; Wang, X.; Woo, J.; Xu, G.; Xu, Z.; Zalewska, A.; Zhang, C.; Zhang, Q.; Zhen, S.; Zipper, W.

2004-01-01

Electron recombination in liquid argon (LAr) is studied by means of charged particle tracks collected in various ICARUS liquid argon TPC prototypes. The dependence of the recombination on the particle stopping power has been fitted with a Birks functional dependence. The simulation of the process of electron recombination in Monte Carlo calculations is discussed. A quantitative comparison with previously published data is carried out

Characterization and Calibration of Large Area Resistive Strip Micromegas Detectors

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00389527; The ATLAS collaboration

2016-01-01

Resistive strip Micromegas detectors are discharge tolerant. They have been tested extensively as small detectors of about 10 x 10 cm$^2$ in size and they work reliably at high rates of 100 kHz/cm$^2$ and above. Tracking resolution well below 100 $\\mu$m has been observed for 100 GeV muons and pions. Micromegas detectors are meanwhile proposed as large area muon precision trackers of 2-3 m$^2$ in size. To investigate possible differences between small and large detectors, a 1 m$^2$ detector with 2048 resistive strips at a pitch of 450 $\\mu$m was studied in the LMU Cosmic Ray Measurement Facility (CRMF) using two 4 $\\times$ 2.2 m$^2$ large Monitored Drift Tube (MDT) chambers for cosmic muon reference tracking. A segmentation of the resistive strip anode plane in 57.6 mm x 93 mm large areas has been realized by the readout of 128 strips with one APV25 chip each and by eleven 93 mm broad trigger scintillators placed along the readout strips. This allows for mapping of homogeneity in pulse height and efficiency, d...

Signal formation processes in Micromegas detectors and quality control for large size detector construction for the ATLAS new small wheel

Energy Technology Data Exchange (ETDEWEB)

Kuger, Fabian

2017-07-31

The Micromegas technology is one of the most successful modern gaseous detector concepts and widely utilized in nuclear and particle physics experiments. Twenty years of R and D rendered the technology sufficiently mature to be selected as precision tracking detector for the New Small Wheel (NSW) upgrade of the ATLAS Muon spectrometer. This will be the first large scale application of Micromegas in one of the major LHC experiments. However, many of the fundamental microscopic processes in these gaseous detectors are still not fully understood and studies on several detector aspects, like the micromesh geometry, have never been addressed systematically. The studies on signal formation in Micromegas, presented in the first part of this thesis, focuses on the microscopic signal electron loss mechanisms and the amplification processes in electron gas interaction. Based on a detailed model of detector parameter dependencies, these processes are scrutinized in an iterating comparison between experimental results, theory prediction of the macroscopic observables and process simulation on the microscopic level. Utilizing the specialized detectors developed in the scope of this thesis as well as refined simulation algorithms, an unprecedented level of accuracy in the description of the microscopic processes is reached, deepening the understanding of the fundamental process in gaseous detectors. The second part is dedicated to the challenges arising with the large scale Micromegas production for the ATLAS NSW. A selection of technological choices, partially influenced or determined by the herein presented studies, are discussed alongside a final report on two production related tasks addressing the detectors' core components: For the industrial production of resistive anode PCBs a detailed quality control (QC) and quality assurance (QA) scheme as well as the therefore required testing tools have been developed. In parallel the study on micromesh parameter optimization

Signal formation processes in Micromegas detectors and quality control for large size detector construction for the ATLAS new small wheel

International Nuclear Information System (INIS)

Kuger, Fabian

2017-01-01

The Micromegas technology is one of the most successful modern gaseous detector concepts and widely utilized in nuclear and particle physics experiments. Twenty years of R and D rendered the technology sufficiently mature to be selected as precision tracking detector for the New Small Wheel (NSW) upgrade of the ATLAS Muon spectrometer. This will be the first large scale application of Micromegas in one of the major LHC experiments. However, many of the fundamental microscopic processes in these gaseous detectors are still not fully understood and studies on several detector aspects, like the micromesh geometry, have never been addressed systematically. The studies on signal formation in Micromegas, presented in the first part of this thesis, focuses on the microscopic signal electron loss mechanisms and the amplification processes in electron gas interaction. Based on a detailed model of detector parameter dependencies, these processes are scrutinized in an iterating comparison between experimental results, theory prediction of the macroscopic observables and process simulation on the microscopic level. Utilizing the specialized detectors developed in the scope of this thesis as well as refined simulation algorithms, an unprecedented level of accuracy in the description of the microscopic processes is reached, deepening the understanding of the fundamental process in gaseous detectors. The second part is dedicated to the challenges arising with the large scale Micromegas production for the ATLAS NSW. A selection of technological choices, partially influenced or determined by the herein presented studies, are discussed alongside a final report on two production related tasks addressing the detectors' core components: For the industrial production of resistive anode PCBs a detailed quality control (QC) and quality assurance (QA) scheme as well as the therefore required testing tools have been developed. In parallel the study on micromesh parameter optimization

Prototype of the ALICE Time Projection Chamber (TPC) Field-Cage

CERN Multimedia

2003-01-01

The ALICE Time Projection Chamber (TPC) is the main particle tracking detector in ALICE. Charged particles crossing the gas of the TPC knock electons out of their atoms, which then drift in in the electric field. By measuring the arrival of electrons at the end of the chamber, the TPC will reconstruct the paths of the original charged particles.

Performance of the First Version of VMM Front-End ASIC with Resistive Micromegas Detectors

CERN Document Server

The ATLAS collaboration

2014-01-01

This note describes the performance of the first version of a front end ASIC, VMM1, being developed for the Micromegas and sTGC detectors of the ATLAS New Small Wheel (NSW) upgrade. The VMM1 ASIC was designed by the micro-electronics group of the Instrumentation Division of Brookhaven National Laboratory. It contains 64-channels of linear, low noise amplifiers with adaptive feedback, charge amplitude peak detectors with time stamp. It can accept inputs of both polarities, features selectable gain and shaping time and has a built-in calibration system. It is designed to operate with micro-pattern gas detectors providing both trigger and tracking information. The VMM1 was tested during August 2012 test beam campaign at SPS/H6 beam line at CERN using micromegas detectors of the Muon ATLAS MicroMega Activity R&D program. We present here the VMM1 configuration, the software that was developed to achieve its operation, as well as the calibration procedure. Furthermore, we present the analysis performed with the...

Design and construction of Micromegas detectors for the ATLAS Muon Spectrometer Upgrade

CERN Document Server

Sessa, Marco

2016-01-01

Thanks to significant technological improvements, developed during a intensive R&D; activity carried out in the last years, large-area Micromegas (MM) will be employed, for the first time, in the High Energy Physics field. Starting from 2019, they will cover a large surface of about 150m2 in the forward regions of the Muon Spectrometer. In this paper, the performances of MM chambers and, in particular, the spatial resolution and the efficiency, obtained using data from different test beam campaigns, will be described. Moreover, it will be shown the present status of the Micromegas chambers construction from the Italian INFN groups, focusing, especially, on the construction procedures and the methodologies developed to obtain the challenging required mechanical precision.

Aging studies of resistive bulk Micromegas chambers for the ATLAS muon spectrometer upgrade

CERN Document Server

Spencer, Katie Louise

2017-01-01

A long-term operation study is presented as a probe of the aging properties of two bulk-resistive Micromegas chambers installed at the GIF$^{++}$ Gamma Irradiation Facility at CERN. Trends in the instantaneous chamber current, recorded over $\\approx$ 500 days of sustained exposure to the GIF$^{++}$ high intensity photon source, are analysed as a function of time in order to identify any signs of detector aging. As part of the study, additional variations in the current due to the changing external conditions of the chambers must be corrected for in order to isolate any aging effects. These include the changing chamber positions with respect to the photon source and the temperature and pressure fluctuations of the detector gas medium. Due to a number of subsets of the total irradiation period in which the exact detector positions are unknown, the aging study at the present time remains inconclusive. As a result, an alternative long-term aging study utilising the instantaneous chamber dark currents is suggested...

Commissioning and calibration of the ALICE-TPC

Energy Technology Data Exchange (ETDEWEB)

Wiechula, Jens

2009-04-21

ALICE (A Large Ion Collider Experiment), is the dedicated heavy-ion experiment at the Large Hadron Collider (LHC) at CERN. It is optimised to reconstruct and identify the particles created in a lead-lead collision with a centre of mass energy of 5.5 TeV. The main tracking detector is a large-volume time-projection chamber (TPC). With an active volume of about 88m{sup 3} and a total readout area of 32.5 m{sup 2} it is the most challenging TPC ever build. A central electrode divides the 5 m long detector into two drift regions. Each readout side is subdivided into 18 inner and 18 outer multi-wire proportional read-out chambers. The readout area is subdivided into 557568 pads, where each pad is read out by an electronic chain. A complex calibration is needed in order to reach the design position-resolution of the reconstructed particle tracks of about 200 {mu}m. The work at hand presents results of the pedestal and noise behaviour of the front-end electronics (FEE), measurements of the pulse-shaping properties of the FEE using results obtained with a calibration pulser and measurements performed with the laser-calibration system. The data concerned were taken during two phases of the TPC commissioning. First measurements were performed in the clean room where the TPC was built. After the TPC was moved underground and built into the experiment, a second round of commissioning took place. Noise measurements in the clean room revealed a very large fraction of pads with noise values larger than the design specifications. Two modifications helped to reduce the 'ground bounce' effect: A desynchronisation in the the start of the readout of groups of channels and a modification in the grounding scheme of the FEE. Further noise measurements were carried out after the TPC has been moved to the experimental area underground. Here even a larger fraction of channels showed too large noise values. To study the shaping properties of the FEE a calibration pulser was used

Commissioning and calibration of the ALICE-TPC

International Nuclear Information System (INIS)

Wiechula, Jens

2009-01-01

ALICE (A Large Ion Collider Experiment), is the dedicated heavy-ion experiment at the Large Hadron Collider (LHC) at CERN. It is optimised to reconstruct and identify the particles created in a lead-lead collision with a centre of mass energy of 5.5 TeV. The main tracking detector is a large-volume time-projection chamber (TPC). With an active volume of about 88m 3 and a total readout area of 32.5 m 2 it is the most challenging TPC ever build. A central electrode divides the 5 m long detector into two drift regions. Each readout side is subdivided into 18 inner and 18 outer multi-wire proportional read-out chambers. The readout area is subdivided into 557568 pads, where each pad is read out by an electronic chain. A complex calibration is needed in order to reach the design position-resolution of the reconstructed particle tracks of about 200 μm. The work at hand presents results of the pedestal and noise behaviour of the front-end electronics (FEE), measurements of the pulse-shaping properties of the FEE using results obtained with a calibration pulser and measurements performed with the laser-calibration system. The data concerned were taken during two phases of the TPC commissioning. First measurements were performed in the clean room where the TPC was built. After the TPC was moved underground and built into the experiment, a second round of commissioning took place. Noise measurements in the clean room revealed a very large fraction of pads with noise values larger than the design specifications. Two modifications helped to reduce the 'ground bounce' effect: A desynchronisation in the the start of the readout of groups of channels and a modification in the grounding scheme of the FEE. Further noise measurements were carried out after the TPC has been moved to the experimental area underground. Here even a larger fraction of channels showed too large noise values. To study the shaping properties of the FEE a calibration pulser was used. To generate signals in

Energy resolution studies of an IROC GEM prototype for the ALICE TPC

Energy Technology Data Exchange (ETDEWEB)

Mathis, Andreas [TU Muenchen, Physik Department E12, Excellence Cluster ' ' Universe' ' , D-85748, Garching (Germany); Collaboration: ALICE-Collaboration

2015-07-01

The ALICE collaboration (A Large Ion Collider Experiment) is planning an upgrade of its central barrel detectors, to be able to cope with the increased LHC luminosity beyond 2018. In order to fully exploit the increase in collision rate to about 50 kHz in Pb-Pb, the TPC is foreseen to be operated in an ungated mode with continuous readout. This demands for a replacement of the currently used, gated MWPC by GEM-based readout chambers, while retaining the present tracking and particle identification capabilities of the TPC via measurement of the specific energy loss (dE/dx). The present baseline solution for the TPC upgrade consists of a stack of four large-sized GEM foils as amplification stage, containing both Standard (S, 140 μm) and Large Pitch (LP, 280 μm) GEM foils arranged in the order S-LP-LP-S. This arrangement has been proven as advantageous in terms of ion backflow and energy resolution. A prototype of an ALICE IROC (Inner Readout Chamber) was equipped with such a quadruple GEM stack, installed inside a field cage and exposed to a beam of electrons and pions from the CERN PS. The performance of the prototype in terms of energy resolution has been evaluated and is presented.

The TPC shielding of the CAST experiment

International Nuclear Information System (INIS)

Ruz, J; Luzon, G; Beltran, B; Carmona, J M; Cebrian, S; Gomez, H; Irastorza, I G; Morales, J; Ortiz de Solorzano, A; RodrIguez, A; Villar, J A

2006-01-01

Sunset solar axions traversing the intense magnetic field of the CERN Axion Solar Telescope (CAST) experiment may be detected in a TPC detector, placed at one side of the magnet, as point-like X-rays signals. This signal could be masked, however, by the inhomogeneous radioactive background of materials and experimental site. Here we present the shielding built to reduce and homogenize the radioactive background levels of the TPC detector

Surfactant mediated extraction of total phenolic contents (TPC) and antioxidants from fruits juices.

Science.gov (United States)

Sharma, Shweta; Kori, Shivpoojan; Parmar, Ankush

2015-10-15

The aim of this study was to enhance the extraction of total phenolic contents (TPC) and antioxidants from fruit juices by the application of surfactants formulations instead of conventional solvents (methanol, ethanol and acetone). A variety of fruit infusions: apple red delicious (apple (rd)) (Malus domestica), Mcintosh apple (apple (i)) (Malus pumila), sweet lemon (Citrus limetta) and mango (Magnifera indica) were studied. Effect of water, organic solvents and five different aqueous surfactant formulations viz. SDS, Brij-35, Brij-58, Triton X-100 and Span-40 were explored for the extraction of TPC and determining the antioxidant activity (AA). The TPC and AA (%) were determined using Folin-Ciocalteu (FCA) and DPPH assay, respectively. The effect of surfactant type, concentration and common organic solvents on the extraction of TPC and AA (%) was studied using UV-visible spectrophotometric technique. Among all the extracting systems employed, Brij-58 showed the highest extraction efficiency. Copyright © 2015 Elsevier Ltd. All rights reserved.

Piggyback resistive Micromegas

CERN Document Server

Attié, D; Durand, D; Desforge, D; Ferrer-Ribas, E; Galán, J; Giomataris, Y; Gongadze, A; Iguaz, F J; Jeanneau, F; de Oliveira, R; Papaevangelou, T; Peyaud, A; Teixeira, A

2013-01-01

Piggyback Micromegas consists in a novel readout architecture where the anode element is made of a resistive layer on a ceramic substrate. The resistive layer is deposited on the thin ceramic substrate by an industrial process which provides large dynamic range of resistivity (10$^6$ to 10$^{10}$\\,M$\\Omega$/square). The particularity of this new structure is that the active part is entirely dissociated from the read-out element. This gives a large flexibility on the design of the anode structure and the readout scheme. Without significant loss, signals are transmitted by capacitive coupling to the read-out pads. The detector provides high gas gain, good energy resolution and the resistive layer assures spark protection for the electronics. This assembly could be combined with modern pixel array electronic ASICs. First tests with different Piggyback detectors and configurations will be presented. This structure is adequate for cost effective fabrication and low outgassing detectors. It was designed to perform ...

Momentum scale in the HARP TPC

CERN Document Server

Catanesi, M G; Edgecock, R; Ellis, M; Soler, F J P; Gössling, C; Bunyatov, S; Krasnoperov, A; Popov, B; Serdiouk, V; Tereschenko, V; Di Capua, E; Vidal-Sitjes, G; Artamonov, A; Giani, S; Gilardoni, S; Gorbunov, P; Grant, A; Grossheim, A; Ivanchenko, V; Kayis-Topaksu, A; Panman, J; Papadopoulos, I; Chernyaev, E; Tsukerman, I; Veenhof, R; Wiebusch, C; Zucchelli, P; Blondel, A; Borghi, S; Morone, M C; Prior, G; Schroeter, R; Meurer, C; Gastaldi, Ugo; Mills, G B; Graulich, J S; Grégoire, G; Bonesini, M; Ferri, F; Kirsanov, M; Bagulya, A; Grichine, V; Polukhina, N; Palladino, V; Coney, L; Schmitz, D; Barr, G; De Santo, A; Bobisut, F; Gibin, D; Guglielmi, A; Mezzetto, M; Dumarchez, J; Dore, U; Orestano, D; Pastore, F; Tonazzo, A; Tortora, L; Booth, C; Howlett, L; Bogomilov, M; Chizhov, M; Kolev, D; Tsenov, R; Piperov, S; Temnikov, P; Apollonio, M; Chimenti, P; Giannini, G; Burguet-Castell, J; Cervera-Villanueva, A; Gómez-Cadenas, J J; Martín-Albo, J; Novella, P; Sorel, M

2007-01-01

Recently a claim was made that the reconstruction of the large angle tracks in the HARP TPC was affected by a momentum bias as large as 15% at 500 MeV/c transverse momentum. In the following we recall the main issues with the momentum measurement in the HARP TPC, and describe the cross-checks made to validate the momentum scale. Proton-proton elastic scattering data off the hydrogen target are used to alibrate the momentum of charged particles with a precision evaluated to be 3.5%. A full description of the time development of the dynamic distortions in the TPC during physics spills is now available together with a correction algorithm. This allows a new cross-check using an enlarged data set made by comparing positive and negative pion elasticscattering data collected with negative polarity of the solenoid magnet. These data confirm the absence of a bias in the sagitta measurement. The dE/dx versus momentum curves are revisited, and shown to provide a confirmation that the HARP momentum calibration is correc...

Overview and outlook on muon survey tomography based on micromegas detectors for unreachable sites technology

Directory of Open Access Journals (Sweden)

Roche I. Lázaro

2016-01-01

Full Text Available The present document describes the functioning principles of the Muon Survey Tomography based on Micromegas detectors for Unreachable Sites Technology and its distinguishing features from other Micromegas-like detectors. Additionally, it addresses the challenges found while operating the first generation and the resulting improvements. Currently, the project Temporal Tomography of the Densitometry by the Measurement of Muons is focused on obtaining a reliable pulse from the micromesh, associated to the passing of a muon, in order to trigger the acquisition and operate in standalone mode. An outlook of the future steps of the project is provided as well.

Investigations of the long-term stability of a GEM-TPC

Energy Technology Data Exchange (ETDEWEB)

Fedorchuk, Oleksiy [Deutsches Elektronen-Synchrotron (DESY), Notkestrasse 85, 22607 Hamburg (Germany); Universitaet Hamburg, Institut fuer Experimentalphysik, Luruper Chaussee 149, 22761 Hamburg (Germany); Collaboration: LCTPC-Deutschland-Collaboration

2016-07-01

For the International Large Detector (ILD) at the planned International Linear Collider (ILC) a Time Projection Chamber (TPC) is foreseen as the main tracking detector. The gas amplification will be done by Micro Pattern Gaseous Detectors (MPGD). One option is to use Gas Electron Multipliers (GEM).While the applicability of GEMs for the gas amplification in a TPC readout has been shown, the focus of the current research is to improve the high voltage stability and reliability of the readout modules. This is a crucial requirement for the operation in the final ILD TPC. The main focus of the research presented in this talk is on studies of the discharge stability and operational features of large area 22 x 18 cm{sup 2} GEM foils. We present systematic studies of the stability of GEM foils under different operation conditions. These studies include measurements and calculations of the dynamic behavior of charges in the GEM foils after a trip. The results will be used to develop methods to avoid destructive discharges in the final readout module.

The use of a Micromegas as a detector for gamma camera

International Nuclear Information System (INIS)

Barbouchi, Asma; Trabelsi, Adel

2008-01-01

The micromegas (Micro Mesh Gaseaous) is a gas detector; it was developed by I.Giomattaris and G.Charpak for application in the field of experimental particle physics. But the polyvalence of this detector makes it to be used in several areas such as medical imaging. This detector has an X-Y readout capability of resolution less than 100μm, an energy resolution down to 14% for energy range 1-10 keV and an overall efficiency of 70%. Monte carlo simulation is widely used in nuclear medicine. It allows predicting the behaviour of system. Gate (Geant4 for Application Tomography Emission) is a platform for monte carlo simulation. It is dedicated to PET/SPECT (Position Emission Tomography / single Photon Emission Tomography) applications. Our goal is to model a gamma camera that use a Micromegas as a detector and to compare their performances (energy resolution, point spread function...) with those of a scintillated gamma camera by using Gate

Search for Axions with Micromegas Detectors in the CERN CAST Experiment

CERN Document Server

YILDIZ, Suleyman Cenk

The CAST experiment is searching for the axion, which is a light, weakly interacting pseudoscalar particle, that is proposed to solve the so called Strong Charge-Parity Problem. The axions CAST is looking for are produced from photons in the solar core and CAST aims to convert them back into photons in a superconducting LHC dipole magnet and detect the photons in the x-ray detectors attached to ends of each magnet bore. CAST uses three micromegas and a CCD detector and can track the Sun during sunset and sunrise. The two of the micromegas take tracking data during the sunset solar tracking, and were used for the first time in 2008. The analysis of the data taken in 2008 with these two detectors show no signal of axions, and new upper limits on the axion mass-coupling constant parameter space are established due to sensitivity of detectors for the axion mass range of $0.38\\eV$ to $0.65\\eV$.

Readout system of TPC/MPD NICA project

Energy Technology Data Exchange (ETDEWEB)

Averyanov, A. V.; Bajajin, A. G.; Chepurnov, V. F.; Cheremukhina, G. A.; Fateev, O. V.; Korotkova, A. M.; Levchanovskiy, F. V.; Lukstins, J.; Movchan, S. A.; Razin, S. V.; Rybakov, A. A.; Vereschagin, S. V., E-mail: vereschagin@jinr.ru; Zanevsky, Yu. V.; Zaporozhets, S. A.; Zruyev, V. N. [Joint Institute for Nuclear Research (Russian Federation)

2015-12-15

The time-projection chamber (TPC) is the main tracking detector in the MPD/NICA. The information on charge-particle tracks in the TPC is registered by the MWPG with cathode pad readout. The frontend electronics (FEE) are developed with use of modern technologies such as application specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), and data transfer to a concentrator via a fast optical interface. The main parameters of the FEE are as follows: total number of channels, ∼95 000; data stream from the whole TPC, 5 GB/s; low power consumption, less than 100 mW/ch; signal to noise ratio (S/N), 30; equivalent noise charge (ENC), <1000e{sup –} (C{sub in} = 10–20 pF); and zero suppression (pad signal rejection ∼90%). The article presents the status of the readout chamber construction and the data acquisition system. The results of testing FEE prototypes are presented.

TPC track distortions IV: post tenebras lux

CERN Document Server

Ammosov, V; Boyko, I; Chelkov, G; Dedovitch, D; Dydak, F; Elagin, A; Gostkin, M; Guskov, A; Koreshev, V; Krumshtein, Z; Nefedov, Y; Nikolaev, K; Wotschack, J; Zhemchugov, A

2007-01-01

We present a comprehensive discussion and summary of static and dynamic track distortions in the HARP TPC in terms of physical origin, mathematical modelling and correction algorithms. `Static' distortions are constant with time, while `dynamic' distortions are distortions that occur only during the 400 ms long accelerator spill. The measurement of dynamic distortions, their mathematical modelling and the correction algorithms build on our understanding of static distortions. In the course of corroborating the validity of our static distortion corrections, their reliability and precision was further improved. Dynamic TPC distortions originate dominantly from the `stalactite' effect: a column of positive-ion charge starts growing at the begin of the accelerator spill, and continues growing with nearly constant velocity out from the sense-wire plane into the active TPC volume. However, the `stalactite' effect is not able to describe the distortions that are present already at the start of the spill and which ha...

Design and Construction of Large Size Micromegas Chambers for the Upgrade of the ATLAS Muon Spectrometer

CERN Document Server

Lösel, Philipp; Müller, Ralph

2015-01-01

Large area Micromegas detectors will be employed for the first time in high-energy physics experiments. A total surface of about $\\mathbf{150~m^2}$ of the forward regions of the Muon Spectrometer of the ATLAS detector at LHC will be equipped with 8-layer Micromegas modules. Each layer covers more than $\\mathbf{2~m^2}$ for a total active area of $\\mathbf{1200~m^2}$. Together with the small strip Thin Gap Chambers they will compose the two New Small Wheels, which will replace the innermost stations of the ATLAS endcap muon tracking system in the 2018/19 shutdown. In order to achieve a 15$\\mathbf{\\%}$ transverse momentum resolution for $\\mathbf{1~TeV}$ muons, in addition to an excellent intrinsic resolution, the mechanical precision of each plane of the assembled module must be as good as $\\mathbf{30~\\mu m}$ along the precision coordinate and $\\mathbf{80~\\mu m}$ perpendicular to the chamber. The design and construction procedure of the Micromegas modules will be presented, as well as the design for the assembly ...

Online calibration of the ALICE-TPC in LHC-Run 2

Energy Technology Data Exchange (ETDEWEB)

Vorobyev, Ivan [Technische Universitaet Muenchen, Excellence Cluster Universe (Germany); Collaboration: ALICE-Collaboration

2015-07-01

The Time Projection Chamber (TPC) is the main tracking detector at the ALICE Experiment at the LHC. Its performance and calibration directly influence the calibration of other detectors in the ALICE central barrel. To address this issue during the first LHC running period, a two-step offline calibration was employed, in which first the TPC and then the other detectors were calibrated. However, such a scheme will not be feasible for the Run 3 period, because the TPC will run in a continuous readout mode, producing a vast amount of data that needs to be significantly compressed on the fly for data storage. This will require the calibration step to run online within the High Level Trigger environment. In this talk, the online calibration concept and the implementation for the ALICE-TPC already in Run 2 are discussed.

Performance Evaluation of the COBRA GEM for the Application of the TPC

Science.gov (United States)

Terasaki, Kohei; Hamagaki, Hideki; Gunji, Taku; Yamaguchi, Yorito

2014-09-01

Suppression of the back-drifting ions from avalanche region to drift space (IBF: Ion Backflow) is the key for a Time Projection Chamber (TPC) since IBF easily distorts the drift field. To suppress IBF, Gating Grid system is widely used for the TPC but this limits the data taking rate. Gas Electron Multiplier (GEM) has advantages in the reduction of IBF and high rate capability. By adopting GEM, it is possible to run a TPC continuously under high rate and high multiplicity conditions. Motivated by the study of IBF reduction for RICH with Thick COBRA, which has been developed by F. A. Amero et al., we developed COBRA GEMs for the application of a TPC. With a stack configuration, IBF reaches about 0.1 ~ 0.5%, which is ×5--10 better IBF than the standard GEMs. However, the measured energy resolution with COBRA is 20% (σ) and this is much worse than the resolution with standard GEMs. Measurement of long-time stability of gain indicates that gain of COBRA varies significantly due to charging up effect. Simulation studies based on Garfield++ are performed for understanding quantitatively the reasons of worse energy resolution and instability of gain. In this presentation, we will report the simulation studies together with the measured performance of the COBRA GEM.

Magnetic field map for a large TPC prototype

International Nuclear Information System (INIS)

Grefe, Christian

2008-12-01

A new e + e - linear collider with an energy of up to 1000 GeV is currently being planned: the International Linear Collider (ILC). It will allow high precision measurements of the Higgs boson and physics beyond the Standard Model. In the Large Detector Concept (LDC) -which is one of the proposed detector concepts for the ILC- a Time Projection Chamber (TPC) is intended as the main tracking device. Within the EUDET project a large TPC prototype is currently being built as an infrastructure to test different gas amplification and readout technologies. The prototype will be operated in a 1T superconducting solenoid magnet -the PCMAG- at the DESY testbeam area. In order to reach the best possible track reconstruction the magnetic field has to be known very precisely throughout the TPC volume. The magnetic field of PCMAG has been measured in July 2007. In this work the creation of a high precision field map from the measurements is presented. The magnet and modelling techniques for its magnetic field are described. A model of the magnet has been created as a best fit from the measurements and its limitations are investigated. The field map will be included in the reconstruction software for the TPC prototype. (orig.)

Magnetic field map for a large TPC prototype

Energy Technology Data Exchange (ETDEWEB)

Grefe, Christian

2008-12-15

A new e{sup +}e{sup -} linear collider with an energy of up to 1000 GeV is currently being planned: the International Linear Collider (ILC). It will allow high precision measurements of the Higgs boson and physics beyond the Standard Model. In the Large Detector Concept (LDC) -which is one of the proposed detector concepts for the ILC- a Time Projection Chamber (TPC) is intended as the main tracking device. Within the EUDET project a large TPC prototype is currently being built as an infrastructure to test different gas amplification and readout technologies. The prototype will be operated in a 1T superconducting solenoid magnet -the PCMAG- at the DESY testbeam area. In order to reach the best possible track reconstruction the magnetic field has to be known very precisely throughout the TPC volume. The magnetic field of PCMAG has been measured in July 2007. In this work the creation of a high precision field map from the measurements is presented. The magnet and modelling techniques for its magnetic field are described. A model of the magnet has been created as a best fit from the measurements and its limitations are investigated. The field map will be included in the reconstruction software for the TPC prototype. (orig.)

Manufacture and performance of the thermal-bonding Micromegas prototype

International Nuclear Information System (INIS)

Zhang, Z.; Yang, Z.; Kang, L.; Guan, L.; Zhang, Y.; Wang, X.; Xu, Z.; Liu, S.; An, Q.; Wang, F.; Zhao, T.

2014-01-01

The micro-mesh gaseous structure (Micromegas) has been significantly developed since it was proposed in 1995 at Saclay (France). Some new construction methods different from ''bulk'' etching technique are under R and D. Here we report the results of several prototypes manufactured with thermal-bonding method, The details of this method and the performances of the chambers are presented. For a 200 × 200 m 2 prototype, the energy resolution of 16% (FWHM) for 5.9 keV x-rays is achieved at a gain of 2000–4000. In addition, the sparking-resistant chammber with a Gemanium anode is under studying

Highly integrated electronics for the star TPC

Energy Technology Data Exchange (ETDEWEB)

Arthur, A.A.; Bieser, F.; Hearn, W.; Kleinfelder, S.; Merrick, T.; Millaud, J.; Noggle, T.; Rai, G.; Ritter, H.G.; Wieman, H. [Lawrence Berkeley Laboratory, CA (United States)

1991-12-31

The concept for the STAR TPC front-end electronics is presented and the progress toward the development of a fully integrated solution is described. It is the goal of the R+D program to develop the complete electronics chain for the STAR central TPC detector at RHIC. It is obvious that solutions chosen e.g. for ALEPH are not adequate for the 150000 channels that need to be instrumented for readout. It will be necessary to perform all the signal processing, digitization and multiplexing directly on the detector in order to reduce per channel cost and the amount of cabling necessary to read out the information. We follow the approach chosen by the EOS TPC project, where the readout electronics on the detector consists of an integrated preamplifier, a hybrid shaping amplifier, an integrated switched capacitor array and a highly multiplexed ADC. The STAR electronics will be further integrated so that approximately 16 channels of the preamplifier, the shaper, the analog store and the ADC will be contained in two integrated circuits located directly on the pad plane.

A Micromegas-based telescope for muon tomography: The WatTo experiment

Science.gov (United States)

Bouteille, S.; Attié, D.; Baron, P.; Calvet, D.; Magnier, P.; Mandjavidze, I.; Procureur, S.; Riallot, M.; Winkler, M.

2016-10-01

This paper reports about the first Micromegas-based telescope built for applications in muon tomography. The telescope consists of four, 50×50 cm2 resistive multiplexed Micromegas with a 2D layout and a self-triggering electronics based on the Dream chip. Thanks to the multiplexing, the four detectors were readout with a single Front-End Unit. The high voltages were provided by a dedicated card using low consumption CAEN miniaturized modules. A nano-PC (Hummingboard) ensured the HV control and monitoring coupled with a temperature feedback as well as the data acquisition and storage. The overall consumption of the instrument yielded 30 W only, i.e. the equivalent of a standard bulb. The telescope was operated outside during 3.5 months to image the water tower of the CEA-Saclay research center, including a 1.5-month campaign with solar panels. The development of autonomous, low consumption muon telescopes with unprecedented accuracy opens new applications in imaging as well as in the field of muon metrology.

A Micromegas-based telescope for muon tomography: The WatTo experiment

Energy Technology Data Exchange (ETDEWEB)

Bouteille, S. [CEA, Centre de Saclay, Irfu/SPhN, 91191 Gif sur Yvette (France); Attié, D.; Baron, P.; Calvet, D.; Magnier, P.; Mandjavidze, I. [CEA, Centre de Saclay, Irfu/Sedi, 91191 Gif sur Yvette (France); Procureur, S., E-mail: Sebastien.Procureur@cea.fr [CEA, Centre de Saclay, Irfu/SPhN, 91191 Gif sur Yvette (France); Riallot, M.; Winkler, M. [CEA, Centre de Saclay, Irfu/Sedi, 91191 Gif sur Yvette (France)

2016-10-21

This paper reports about the first Micromegas-based telescope built for applications in muon tomography. The telescope consists of four, 50×50 cm{sup 2} resistive multiplexed Micromegas with a 2D layout and a self-triggering electronics based on the Dream chip. Thanks to the multiplexing, the four detectors were readout with a single Front-End Unit. The high voltages were provided by a dedicated card using low consumption CAEN miniaturized modules. A nano-PC (Hummingboard) ensured the HV control and monitoring coupled with a temperature feedback as well as the data acquisition and storage. The overall consumption of the instrument yielded 30 W only, i.e. the equivalent of a standard bulb. The telescope was operated outside during 3.5 months to image the water tower of the CEA-Saclay research center, including a 1.5-month campaign with solar panels. The development of autonomous, low consumption muon telescopes with unprecedented accuracy opens new applications in imaging as well as in the field of muon metrology.

The NA36 time projection chamber: An interim report on a TPC designed for a relativistic heavy ion experiment

International Nuclear Information System (INIS)

Diebold, G.E.

1987-01-01

Since its conception in the early 1970s, the Time Projection Chamber (TPC) has found application in several areas of particle physics ranging from e + e - collider experiments to rare decay studies of lepton nonconservation. A new and promising area of application for the TPC is the study of relativistic heavy ion collisions (RHIC). Presented here is an interim report on the first TPC for this field of physics, the NA36 TPC, being developed by Berkeley (LBL) for RHIC at the CERN SPS. Emphasis is placed on the operational and design considerations implemented to optimize the performance of the NA36 TPC in the study of central rapidity strange baryons produced in RHIC. The NA36 TPC volume is rectangular with an endcap area 0.5 m x 1.0 m and a maximum drift distance of 0.5 m. The drift volume is filled with Ar-CH 4 (9%) at one atmosphere. A total of 6400 channels of time digitizing electronics instrument 66% of the endcap in a wedge shaped area matched to fixed target kinematics. 6 refs., 5 figs

Performance Studies of Resistive Micromegas Detectors for the Upgrade of the ATLAS Muon Spectrometer

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00387450

2017-01-01

With the high luminosity upgrade of the LHC the ATLAS Muon spectrometer will face increased particle rates, requiring an upgrade of the innermost end-cap detectors with a high-rate capable technology. Micromegas have been chosen as main tracking technology for this New Small Wheel upgrade. In an intense R$\\&$D and prototype phase the technology has proven to meet the stringent performance requirements of highly efficient particle detection with better than 100$\\rm{\\mu m}$ spatial resolution, independent of the track incidence angle up to 32$^\\circ$, in a magnetic field B $\\leq$ 0.3 T and at background hit rate of up to 15kHz/cm$^2$.

An insulating grid spacer for large-area MICROMEGAS chambers

International Nuclear Information System (INIS)

Bernard, D.; Delagrange, H.; D'Enterria, D.G.; Guay, M.L.M. Le; Martinez, G.; Mora, M.J.; Pichot, P.; Roy, D.; Schutz, Y.; Gandi, A.; Oliveira, R. de

2002-01-01

We present a novel design for large-area gaseous detectors based on the MICROMEGAS technology. This technology incorporates an insulating grid, sandwiched between the micro-mesh and the anode-pad plane, which provides a uniform 200 μm amplification gap. The uniformity of the amplification gap thickness has been verified. The gain performances of the detector are presented and compared to the values obtained with detectors using cylindrical micro spacers. The new design presents several technical and financial advantages

A large ungated TPC with GEM amplification

Science.gov (United States)

Berger, M.; Ball, M.; Fabbietti, L.; Ketzer, B.; Arora, R.; Beck, R.; Böhmer, F. V.; Chen, J.-C.; Cusanno, F.; Dørheim, S.; García, F.; Hehner, J.; Herrmann, N.; Höppner, C.; Kaiser, D.; Kis̆, M.; Kleipa, V.; Konorov, I.; Kunkel, J.; Kurz, N.; Leifels, Y.; Müllner, P.; Münzer, R.; Neubert, S.; Rauch, J.; Schmidt, C. J.; Schmitz, R.; Soyk, D.; Vandenbroucke, M.; Voss, B.; Walther, D.; Zmeskal, J.

2017-10-01

A Time Projection Chamber (TPC) is an ideal device for the detection of charged particle tracks in a large volume covering a solid angle of almost 4 π. The high density of hits on a given particle track facilitates the task of pattern recognition in a high-occupancy environment and in addition provides particle identification by measuring the specific energy loss for each track. For these reasons, TPCs with Multiwire Proportional Chamber (MWPC) amplification have been and are widely used in experiments recording heavy-ion collisions. A significant drawback, however, is the large dead time of the order of 1 ms per event generated by the use of a gating grid, which is mandatory to prevent ions created in the amplification region from drifting back into the drift volume, where they would severely distort the drift path of subsequent tracks. For experiments with higher event rates this concept of a conventional TPC operating with a triggered gating grid can therefore not be applied without a significant loss of data. A continuous readout of the signals is the more appropriate way of operation. This, however, constitutes a change of paradigm with considerable challenges to be met concerning the amplification region, the design and bandwidth of the readout electronics, and the data handling. A mandatory prerequisite for such an operation is a sufficiently good suppression of the ion backflow from the avalanche region, which otherwise limits the tracking and particle identification capabilities of such a detector. Gas Electron Multipliers (GEM) are a promising candidate to combine excellent spatial resolution with an intrinsic suppression of ions. In this paper we describe the design, construction and the commissioning of a large TPC with GEM amplification and without gating grid (GEM-TPC). The design requirements have driven innovations in the construction of a light-weight field-cage, a supporting media flange, the GEM amplification and the readout system, which are

Development of the MICROMEGAS Detector for Measuring the Energy Spectrum of Alpha Particles by using a 241-Am Source

CERN Document Server

Kim, Do Yoon; Shin, Jae Won; Park, Tae-Sun; Hong, Seung-Woo; Andriamonje, Samuel; Kadi, Yacine; Tenreiro, Claudio

2016-01-01

We have developed MICROMEGAS (MICRO MEsh GASeous) detectors for detecting {\\alpha} particles emitted from an 241-Am standard source. The voltage applied to the ionization region of the detector is optimized for stable operation at room temperature and atmospheric pressure. The energy of {\\alpha} particles from the 241-Am source can be varied by changing the flight path of the {\\alpha} particle from the 241 Am source. The channel numbers of the experimentally-measured pulse peak positions for different energies of the {\\alpha} particles are associated with the energies deposited by the alpha particles in the ionization region of the detector as calculated by using GEANT4 simulations; thus, the energy calibration of the MICROMEGAS detector for {\\alpha} particles is done. For the energy calibration, the thickness of the ionization region is adjusted so that {\\alpha} particles may completely stop in the ionization region and their kinetic energies are fully deposited in the region. The efficiency of our MICROMEGA...

Gas pixel detector for X-ray observation

CERN Document Server

Attié, D; Chefdeville, M; Colas, P; Delagnes, E; Giomataris, Y; van der Graaf, H; Llopart, X; Timmermans, J; Visschers, J

2009-01-01

We report on the status of the R&D for a digital Time Projection Chamber (TPC) based on Micromegas (MICRO MEsh GAseous Structure) detectors using the CMOS chip TimePix as a direct readout anode protected by highly resistive a-Si:H layer. A small chamber was built as a demonstrator of the 2-D and 3-D imaging capabilities of this technique. We illustrate the new capabilities of this detector for X-ray observation with data taken from radioactive sources. This small TPC is a very useful tool both for studying gas properties thanks to its good efficiency for single electrons, and for reconstructing photoelectron direction for use as a soft X-ray polarimeter.

Performance of the micromegas detector in the CAST experiment

International Nuclear Information System (INIS)

Aune, S.; Dafni, T.; Fanourakis, G.; Ferrer Ribas, E.; Geralis, T.; Giganon, A.; Giomataris, Y.; Irastorza, I.G.; Kousouris, K.; Zachariadou, K.

2007-01-01

The gaseous micromegas detector designed for the CERN Axion search experiment CAST, operated smoothly during Phase-I, which included the 2003 and 2004 running periods. It exhibited linear response in the energy range of interest (1-10 keV), good spatial sensitivity and energy resolution (15-19% FWHM at 5.9 keV) as well as remarkable stability. The detector's upgrade for the 2004 run, supported by the development of advanced offline analysis tools, improved the background rejection capability, leading to an average rate 5x10 -5 counts/s/cm 2 /keV with 94% cut efficiency. Also, the origin of the detected background was studied with a Monte-Carlo simulation, using the GEANT4 package

Front-end electronics and readout system for the ILD TPC

CERN Document Server

Hedberg, V; Lundberg, B; Mjörnmark, U; Oskarsson, A; Österman, L; De Lentdecker, G; Yang, Y; Zhang, F

2015-01-01

A high resolution TPC is the main option for a central tracking detector at the future International Linear Collider (ILC). It is planned that the MPGD (Micro Pattern Gas Detector) technology will be used for the readout. A Large Prototype TPC at DESY has been used to test the performance of MPGDs in an electron beam of energies up to 6 GeV. The first step in the technology development was to demonstrate that the MPGDs are able to achieve the necessary performance set by the goals of ILC. For this ’proof of principle’ phase, the ALTRO front-end electronics from the ALICE TPC was used, modified to adapt to MPGD readout. The proof of principle has been verified and at present further improvement of the MPGD technology is going on, using the same readout electronics. The next step is the ’feasibility phase’, which aims at producing front-end electronics comparable in size (few mm2) to the readout pads of the TPC. This development work is based on the succeeding SALTRO16 chip, which combines the analogue ...

TPC spectrometer for measuring the e+ spectrum in μ decay

International Nuclear Information System (INIS)

Kinnison, W.W.

1983-01-01

The Time Projection Chamber (TPC) being used at the Los Alamos Meson Physics Facility (LAMPF) for a high-statistics normal muon-decay experiment is described. It is shown how the experiment will improve upon the limits of the weak-interaction coupling constants by a factor of 5 through the measurement of the positron momentum and direction of emission with respect to the muon-polarization vector for 10 8 decays of stopped, polarized, positive muons. The TPC apparatus is described, and it is shown that even though more work is to be done to improve the detector acceptance and individual coordinate resolutions, for certain track topologies, the TPC already has a momentum resolution of 0.7% (sigma)

TPC cross-talk correction: CERN-Dubna-Milano algorithm and results

CERN Document Server

De Min, A; Guskov, A; Krasnoperov, A; Nefedov, Y; Zhemchugov, A

2003-01-01

The CDM (CERN-Dubna-Milano) algorithm for TPC Xtalk correction is presented and discussed in detail. It is a data-driven, model-independent approach to the problem of Xtalk correction. It accounts for arbitrary amplitudes and pulse shapes of signals, and corrects (almost) all generations of Xtalk, with a view to handling (almost) correctly even complex multi-track events. Results on preamp amplification and preamp linearity from the analysis of test-charge injection data of all six TPC sectors are presented. The minimal expected error on the measurement of signal charges in the TPC is discussed. Results are given on the application of the CDM Xtalk correction to test-charge events and krypton events.

Design, construction, quality checks and test results of first resistive-Micromegas read-out boards for the ATLAS experiment

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00215943; The ATLAS collaboration; Kuger, Fabian

2015-01-01

The development work carried out at CERN to push the Micromegas technology to a new frontier is now coming to an end. The construction of the first read-out boards for the upgrade of the ATLAS muon system will demonstrate in full-scale the feasibility of this ambitious project. The read-out boards, representing the heart of the detector, are manufactured in industries, making the Micromegas for ATLAS the first MPGD for a large experiment with a relevant part industrially produced. The boards are 50 cm wide and up to 220 cm long, carrying copper strips 315 μm wide with 415 μm pitch. Interconnected resistive strips, having the same pattern as the copper strips, provide spark protection. The boards are completed by the creation of cylindrical pillars 128 μm high, 280 μm in diameter and arranged in a triangular array 7 mm aside. The total number of boards to be produced for ATLAS is 2048 of 32 different types. We will review the main design parameters of the read-out boards for the ATLAS Micromegas, following...

Construction and Quality Assurance of Large Area Resistive Strip Micromegas for the Upgrade of the ATLAS Muon Spectrometer

CERN Document Server

Losel, Philipp Jonathan; The ATLAS collaboration

2017-01-01

To cope with the increased background induced hit rate of up to ~15 kHz/cm$^2$ in the innermost stations of the muon endcap system of the ATLAS experiment after the high-luminosity upgrade of the LHC, the currently used precision detectors will be replaced by resistive strip Micromegas in 2019. In the "New Small Wheel" the Micromegas will be arranged in two times four detection layers built of trapezoidally shaped quadruplets of four different sizes.The Micromegas quadruplets will consist of 5 panels, 3 drift panels and 2 readout panels, made of aluminum honeycomb core sandwiched by printed circuit boards (PCBs). To achieve 15% transverse momentum resolution for 1 TeV muons and thus a spatial resolution in a single plane of about 100 $\\mu$m, each active plane has to have an accuracy of 80 $\\mu$m perpendicular to the plane and the alignment of the readout strips on the individual PCBs and particularly the alignment within a quadruplet must fulfill a challenging precision of 30 $\\mu$m. The required mechanical p...

Analysis of HARP TPC krypton data

CERN Document Server

Dydak, F

2004-01-01

This memo describes the procedure which was adopted to equalize the response of the 3972 pads of the HARP TPC, using radioactive 83mKr gas. The results obtained from the study of reconstructed krypton clusters in the calibration data taken in 2002 are reported. Two complementary methods were employed in the data analysis. Compatible results were obtained for channel-to-channel equalization constants. An estimate of the overall systematic uncertainty was derived.

An insulating grid spacer for large-area MICROMEGAS chambers

CERN Document Server

Bernard, D; D'Enterria, D G; Le Guay, M; Martínez, G; Mora, M J; Pichot, P; Roy, D; Schutz, Y; Gandi, A; De Oliveira, R

2002-01-01

We present an original design for large area gaseous detectors based on the MICROMEGAS technology. This technology incorporates an insulating grid, sandwiched between the micro-mesh and the anode-pad plane, which provides an uniform 200 $\\mu$m amplification gap. The uniformity of the amplification gap thickness has been verified under several experimental conditions. The gain performances of the detector are presented and compared to the values obtained with detectors using cylindrical micro spacers. The new design presents several technical and financial advantages.

Solid-Liquid Extraction Kinetics of Total Phenolic Compounds (TPC from Red Dates

Directory of Open Access Journals (Sweden)

Bee Lin Chua

2018-01-01

Full Text Available Red dates are one of the most famous herbal plants in making traditional Chinese medicine. They contain large amount of bioactive compounds. The objectives of this research were to optimise the crude extract yield and total phenolic compounds (TPC yield from red dates using response surface methodology (RSM and model the extraction kinetics of TPC yield from red dates. Date fruits were dried in an oven under temperatures 50°C, 60°C, 70°C and 80°C until a constant weight was obtained. The optimum drying temperature was 60°C as it gave the highest crude extract yield and TPC yield. Besides that, single factor experiments were used to determine the optimum range of four extraction parameters which were: liquid-solid ratio (10-30 ml/g; ultrasonic power (70-90%; extraction temperature (50-70°C; and extraction time (40-60min. The optimum range of the four parameters were further optimised using the Box-Behken Design (BBD of RSM. The extraction conditions that gave the highest crude extract yield and TPC yield were chosen. The optimum value for liquid-solid ratio, ultrasonic power, extraction temperature and extraction time were 30ml/g, 70%, 60°C and 60 min respectively. The two equations generated from RSM were reliable and can be used to predict the crude extract yield and TPC yield. The higher the extraction temperature, liquid-solid ratio, and extraction time and lower ultrasonic power, the higher the crude extract and TPC yield. Finally, the results of TPC yield versus time based on the optimum extraction parameters from RSM optimisation were fitted into three extraction kinetic models (Peleg’s model, Page’s model and Ponomaryov’s model. It was found that the most suitable kinetic model to represent the extraction process of TPC from red dates was Page’s model due to its coefficient of determination (R2 was the closest to unity, 0.9663 while its root mean square error (RMSE was the closest to zero, 0.001534.

The Readout Control Unit of the ALICE TPC

CERN Document Server

Lien, J A; Musa, L

2004-01-01

The ALICE Time Projection Chamber (TPC) is the main tracking detector of the central barrel of the ALICE (A Large Ion Collider) Experiment at the Large Hadron Collider (LHC), being constructed at CERN, Geneva. It is a 88 m$^{3}$ cylinder filled with gas and divided into two drift regions by the central electrode located at its axial center. The readout chambers of the TPC are multi-wire proportional chambers with cathode pad readout. About 570 000 pads are read-out by an electronics chain of amplification, digitalization and pre-processing. One of the challenges in designing the TPC for ALICE is the design of Front End Electronics (FEE) to cope with the data rates and the channel occupancy. The Readout Control Unit (RCU), which is presented in this work, is designed to control and monitor the Front End Electronics, and to collect and ship data to the High Level Trigger and the Data Acquisition System, via the Detector Data Link (DDL - optical fibre). The RCU must be capable of reading out up to 200 Mbytes/s f...

Slow Control System for the NIFFTE Collaboration TPC

Science.gov (United States)

Ringle, Erik; Niffte Collaboration Collaboration

2011-10-01

As world energy concerns continue to dominate public policy in the 21st century, the need for cleaner and more efficient nuclear power is necessary. In order to effectively design and implement plans for generation IV nuclear reactors, more accurate fission cross-section measurements are necessary. The Neutron Induced Fission Fragment Tracking Experiment (NIFFTE) collaboration, in an effort to meet this need, has constructed a Time Projection Chamber (TPC) which aims to reduce the uncertainty of the fission cross-section to less than 1%. Using the Maximum Integration Data Acquisition System (MIDAS) framework, slow control measurements are integrated into a single interface to facilitate off-site monitoring. The Hart Scientific 1560 Black Stack will be used with two 2564 Thermistor Scanner Modules to monitor internal temperature of the TPC. A Prologix GPIB to Ethernet controller will be used to interface the hardware with MIDAS. This presentation will detail the design and implementation of the slow control system for the TPC. This work was supported by the U.S. Department of Energy Division of Energy Research.

Results from the STAR TPC system test

International Nuclear Information System (INIS)

Betts, W.

1996-01-01

A system test of various components of the Solenoidal Tracker at RHIC (STAR) detector, operating in concern, has recently come on-line. Communication between a major sub-detector, a sector of the Time Projection Chamber (TPC), and the trigger, data acquisition and slow controls systems has been established, enabling data from cosmic ray muons to be collected. First results from an analysis of the TPC data are presented. These include measurements of system noise, electronic parameters such as amplifier gains and pedestal values, and tracking resolution for cosmic ray muons and laser induced ionization tracks. A discussion on the experience gained in integrating the different components for the system test is also given

New pixelized Micromegas detector for the COMPASS experiment

International Nuclear Information System (INIS)

Neyret, D; Anfreville, M; Bedfer, Y; Burtin, E; D'Hose, N; Giganon, A; Kunne, F; Magnon, A; Marchand, C; Paul, B; Platchkov, S; Vandenbroucke, M; Ketzer, B; Konorov, I

2009-01-01

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

Performance of Multiplexed XY Resistive Micromegas detectors in a high intensity beam

Science.gov (United States)

Banerjee, D.; Burtsev, V.; Chumakov, A.; Cooke, D.; Depero, E.; Dermenev, A. V.; Donskov, S. V.; Dubinin, F.; Dusaev, R. R.; Emmenegger, S.; Fabich, A.; Frolov, V. N.; Gardikiotis, A.; Gninenko, S. N.; Hösgen, M.; Karneyeu, A. E.; Ketzer, B.; Kirsanov, M. M.; Konorov, I. V.; Kramarenko, V. A.; Kuleshov, S. V.; Levchenko, E.; Lyubovitskij, V. E.; Lysan, V.; Mamon, S.; Matveev, V. A.; Mikhailov, Yu. V.; Myalkovskiy, V. V.; Peshekhonov, V. D.; Peshekhonov, D. V.; Polyakov, V. A.; Radics, B.; Rubbia, A.; Samoylenko, V. D.; Tikhomirov, V. O.; Tlisov, D. A.; Toropin, A. N.; Vasilishin, B.; Arenas, G. Vasquez; Ulloa, P.; Crivelli, P.

2018-02-01

We present the performance of multiplexed XY resistive Micromegas detectors tested in the CERN SPS 100 GeV/c electron beam at intensities up to 3 . 3 × 105e- /(s ṡcm2) . So far, all studies with multiplexed Micromegas have only been reported for tests with radioactive sources and cosmic rays. The use of multiplexed modules in high intensity environments was not explored due to the effect of ambiguities in the reconstruction of the hit point caused by the multiplexing feature. For the specific mapping and beam intensities analyzed in this work with a multiplexing factor of five, more than 50% level of ambiguity is introduced due to particle pile-up as well as fake clusters due to the mapping feature. Our results prove that by using the additional information of cluster size and integrated charge from the signal clusters induced on the XY strips, the ambiguities can be reduced to a level below 2%. The tested detectors are used in the CERN NA64 experiment for tracking the incoming particles bending in a magnetic field in order to reconstruct their momentum. The average hit detection efficiency of each module was found to be ∼96% at the highest beam intensities. By using four modules a tracking resolution of 1.1% was obtained with ∼85% combined tracking efficiency.

Construction of two large-size four-plane micromegas detectors

CERN Document Server

Bianco, Michele; Degrange, Jordan; De Oliveira, Rui; Düdder, Andreas; Farina, Edoardo; Kuger, Fabian; Iengo, Paolo; Gomez, Francisco Perez; Lin, Tai-Hua; Schott, Matthias; Sekhniaidze, Givi; Sforza, Federico; Sidiropoulou, Ourania; Valderanis, Chrysostomos; Vergain, Maurice; Wotschack, Jörg

2016-01-01

We report on the construction and initial performance studies of two micromegas detector quadruplets with an area of 0.5 m$^2$. They serve as prototypes for the planned upgrade project of the ATLAS muon system. Their design is based on the resistive-strip technology and thus renders the detectors spark tolerant. Each quadruplet comprises four detection layers with 1024 readout strips and a strip pitch of 415 $\\mu$m. In two out of the four layers the strips are inclined by $\\pm$1.5$^{\\circ}$ to allow for the measurement of a second coordinate. We present the detector concept and report on the experience gained during the detector construction. In addition an evaluation of the detector performance with cosmic rays and test-beam data is given.

A GEM-TPC prototype with low-Noise highly integrated front-end electronics for linear collider studies

CERN Document Server

Kappler, Steffen; Kaminski, Jochen; Ledermann, Bernhard; Müller, Thomas; Ronan, Michael T; Ropelewski, Leszek; Sauli, Fabio; Settles, Ronald

2004-01-01

Connected to the linear collider project, studies on the readout of time projection chambers (TPCs) based on the gas electron multiplier (GEM) are ongoing. Higher granularity and intrinsically suppressed ion feedback are the major advantages of this technology. After a short discussion of these issues, we present the design of a small and very flexible TPC prototype, whose cylindrical drift volume can be equipped with endcaps of different gas detector types. An endcap with multi-GEM readout is currently set up and successfully operated with a low-noise highly integrated front-end electronics. We discuss results of measurements with this system in high intensity particle beams at CERN, where 99.3 plus or minus 0.2% single-pad-row efficiency could be achieved at an effective gain of 2.5 multiplied by 10**3 only, and spatial resolutions down to 63 plus or minus 3 mum could be demonstrated. Finally, these results are extrapolated to the high magnetic field in a linear collider TPC. 5 Refs.

Contribution of a Liquid Argon TPC to T2K Neutrino Experiment

Science.gov (United States)

Meregaglia, A.; Rubbia, A.

2006-08-01

A 2 km LAr detector would be an important asset for the T2K experiment. Different physics scenarios are considered and for each one the role of a LAr TPC in enhancing the ultimate sensitivity on theta 13 is studied. The large sample of neutrino interactions in the GeV region would provide crucial information for the study of different types of reactions and of nuclear effects, whereas the inner target would give a direct measurement of the cross sections ratio between Water and Argon. Such a detector would also be an important milestone for the LAr TPC technique providing an extremely valuable experience for future large LAr detectors.

Behavior of TPC`s in a high particle flux environment

Energy Technology Data Exchange (ETDEWEB)

Etkin, A.; Eiseman, S.E.; Foley, K.J.; Hackenburg, R.W.; Longacre, R.S.; Love, W.A.; Morris, T.W.; Platner, E.D.; Saulys, A.C.; Lindenbaum, S.J. [Brookhaven National Lab., Upton, NY (United States); Chan, C.S.; Kramer, M.A.; Zhao, K.H.; Zhu, Y. [City College of New York, New York (United States); Hallman, T.J.; Madansky, L. [Johns Hopkins Univ., Baltimore, MD (United States); Ahmad, S.; Bonner, B.E.; Buchanan, J.A.; Chiou, C.N.; Clement, J.M.; Mutchler, G.S.; Roberts, J.B. [Bonner Nuclear Lab., Houston, TX (United States)

1991-12-31

TPC`s (Time Projection Chamber) used in E-810 at the TAGS (Alternating Gradient Synchrotron) were exposed to fluxes equivalent to more than 10 minimum ionizing particles per second to find if such high fluxes cause gain changes or distortions of the electric field. Initial results of these and other tests are presented and the consequences for the RHIC (Relativistic Heavy Ion Collider) TPC-based experiments are discussed.

Construction and Quality Assurance of Large Area Resistive Strip Micromegas for the Upgrade of the ATLAS Muon Spectrometer at LHC/CERN

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00389527; The ATLAS collaboration

2017-01-01

Large area Micromegas detectors will be employed for the first time in high-energy physics experiments. To cope with increasing background rates, associated with the steadily increasing luminosity of LHC to 10 times design luminosity, the present detector technology in the current innermost stations of the muon endcap system of the ATLAS experiment (the Small Wheel), will be replaced in 2019 by resistive strip Micromegas and small strip TGC detectors. Both technologies will provide tracking and trigger information. In the ``New Small Wheel'' the Micromegas will be arranged in eight detection layers built of trapezoidally shaped quadruplets of four different sizes covering in total about 1200\\,m$^2$ of detection plane. In order to achieve 15\\,\\% transverse momentum resolution for 1 TeV muons, a challenging mechanical precision is required in the construction of each active plane, with an alignment of the readout strips at the level of 30\\,\\textmu m along the precision coordinate and 80\\,\\textmu m perpendicular...

Development of a time projection chamber using gas electron multipliers (GEM-TPC)

International Nuclear Information System (INIS)

Oda, S.X.; Hamagaki, H.; Ozawa, K.; Inuzuka, M.; Sakaguchi, T.; Isobe, T.; Gunji, T.; Morino, Y.; Saito, S.; Yamaguchi, Y.L.; Sawada, S.; Yokkaichi, S.

2006-01-01

We developed a prototype time projection chamber using gas electron multipliers (GEM-TPC) for high energy heavy ion collision experiments. To investigate its performance, we conducted a beam test with three kinds of gases (Ar(90%)-CH 4 (10%), Ar(70%)-C 2 H 6 (30%) and CF 4 ). Detection efficiency of 99%, and spatial resolution of 79μm in the pad-row direction and 313μm in the drift direction were achieved. The test results show that the GEM-TPC meets the requirements for high energy heavy ion collision experiments. The configuration and performance of the GEM-TPC are described

Noise Characterization and Filtering in the MicroBooNE Liquid Argon TPC

Energy Technology Data Exchange (ETDEWEB)

Acciarri, R.; et al.

2017-05-20

The low-noise operation of readout electronics in a liquid argon time projection chamber (LArTPC) is critical to properly extract the distribution of ionization charge deposited on the wire planes of the TPC, especially for the induction planes. This paper describes the characteristics and mitigation of the observed noise in the MicroBooNE detector. The MicroBooNE's single-phase LArTPC comprises two induction planes and one collection sense wire plane with a total of 8256 wires. Current induced on each TPC wire is amplified and shaped by custom low-power, low-noise ASICs immersed in the liquid argon. The digitization of the signal waveform occurs outside the cryostat. Using data from the first year of MicroBooNE operations, several excess noise sources in the TPC were identified and mitigated. The residual equivalent noise charge (ENC) after noise filtering varies with wire length and is found to be below 400 electrons for the longest wires (4.7 m). The response is consistent with the cold electronics design expectations and is found to be stable with time and uniform over the functioning channels. This noise level is significantly lower than previous experiments utilizing warm front-end electronics.

Some TPC measurements in an oxygen beam at the AGS

International Nuclear Information System (INIS)

Love, W.A.; Etkin, A.; Foley, K.J.; Hackenburg, R.W.; Longacre, R.S.; Morris, T.W.; Platner, E.D.; Saulys, A.C.; Bonner, B.E.; Buchanan, J.A.; Chiou, C.N.; Clement, J.M.; Corcoran, M.D.; Krishna, N.; Kruk, J.W.; Miettinen, H.E.; Mutchler, G.S.; Nessi-Tedaldi, F.; Nessi, M.; Phillips, G.C.; Roberts, J.B.; Chan, C.S.; Kramer, M.A.; Hallman, T.J.; Madansky, L.; Lindenbaum, S.J.

1989-01-01

The principal detector for AGS Experiment 810 is a Time Projection Chamber (TPC) in which it is intended to measure momenta and angles of a major fraction of the charged particles from each light ion collision. This report describes the results of a test of a prototype of the TPC in a beam of (14.6x16=233.6 GeV/c) oxygen ions run in June of this year. (orig.)

The development of Micromegas, a new gaseous position detector; Le developpement de micromegas, un nouveau detecteur gazeux de position a microgrille

Energy Technology Data Exchange (ETDEWEB)

Puill, G

2000-06-01

Micromegas (micro mesh gaseous structure) is a new detector based on a double structure, it is made of 2 different zones separated by a micro-grid. This detector is set in a tight container in which flows a mix of an inert gas with a few percents of a moderator gas that is needed for the right operating of the device. The part that is met by the incident particle is the conversion zone where the particle will lose a part of its energy by creating electron-ion pairs coming from the ionisation of the atoms of the gas mix. The other part is the amplifying zone, this zone is delimited by the micro-grid and the bottom of the detector and is about 100 microns broad, tracks are set on the bottom and each track is linked to an amplifying line. Micromegas detects charged particles but is not insensitive to other particles, its operating conditions are dependent on many parameters. The width of the conversion zone, the gas mix composition and the type of incident particles will determine the quantity of energy released and then its efficiency to detect all particles. The width of the conversion zone and the nature of the gas mix will have an influence on the spatial accuracy. The detector gain is dependent on the gas mix, the electric field, the gas pressure and the width of the amplifying zone. The nature of the gas mix is expected to have an effect on the spatial resolution. The signal lifetime will depend not only on the gas mix but also on the width of the amplifying zone. We have to notice that the grid mesh has to fit the width of the amplifying zone. This work is dedicated to the study of this detector, to determine its operating range, to evaluate the influence of all the parameters quoted above and to give a review of its performance. (A.C.)

A Micromegas Detector for Neutron Beam Imaging at the n_TOF Facility at CERN

CERN Document Server

Belloni, F; Berthoumieux, E; Calviani, M; Chiaveri, E; Colonna, N; Giomataris, Y; Guerrero, C; Gunsing, F; Iguaz, F J; Kebbiri, M; Pancin, J; Papaevangelou, T; Tsinganis, A; Vlachoudis, V; Altstadt, S; Andrzejewski, J; Audouin, L; Barbagallo, M; Bécares, V; Bečvář, F; Billowes, J; Boccone, V; Bosnar, D; Brugger, M; Calviño, F; Cano-Ott, D; Carrapiço, C; Cerutti, F; Chiaveri, E; Chin, M; Cortés, G; Corté-Giraldo, M A; Diakaki, M; Domingo-Pardo, C; Duran, I; Dzysiuk, N; Eleftheriadis, C; Ferrari, A; Fraval, K; Ganesan, S; García, A R; Giubrone, G; Gómez-Hornillos, M B; Gonçalves, I F; González-Romero, E; Griesmayer, E; Gurusamy, P; Jenkins, D G; Jericha, E; Kadi, Y; Käppeler, F; Karadimos, D; Koehler, P; Kokkoris, M; Krtička, M; Kroll, J; Langer, C; Lederer, C; Leeb, H; Leong, L S; Losito, R; Manousos, A; Marganiec, J; Marítnez, T; Massimi, C; Mastinu, P F; Mastromarco, M; Meaze, M; Mendoza, E; Mengoni, A; Milazzo, P M; Mingrone, F; Mirea, M; Mondalaers, W; Paradela, C; Pavlik, A; Perkowski, J; Plompen, A J M; Praena, J; Quesada, J M; Rauscher, T; Reifarth, R; Riego, A; Roman, F; Rubbia, C; Sarmento, R; Schillebeeckx, P; Schmidt, S; Tagliente, G; Tain, J L; Tarrío, D; Tassan-Got, L; Valenta, S; Vannini, G; Variale, V; Vaz, P; Ventura, A; Versaci, R; Vermeulen, M J; Vlastou, R; Wallner, A; Ware, T; Weigand, M; Weiss, C; Wright, T J; Žugec, P

2014-01-01

Micromegas (Micro-MEsh Gaseous Structure) detectors are gas detectors consisting of a stack of one ionization and one proportional chamber. A micromesh separates the two communicating regions, where two different electric fields establish respectively a charge drift and a charge multiplication regime. The n\\_TOF facility at CERN provides a white neutron beam (from thermal up to GeV neutrons) for neutron induced cross section measurements. These measurements need a perfect knowlodge of the incident neutron beam, in particular regarding its spatial profile. A position sensitive micromegas detector equipped with a B-10 based neutron/charged particle converter has been extensively used at the n\\_TOF facility for characterizing the neutron beam profile and extracting the beam interception factor for samples of different size. The boron converter allowed to scan the energy region of interest for neutron induced capture reactions as a function of the neutron energy, determined by the time of flight. Experimental ...

Progress on the superconducting magnet for the time projection chamber experiment (TPC) at PEP

International Nuclear Information System (INIS)

Green, M.A.; Eberhard, P.H.; Burns, W.A.

1980-01-01

The TPC (Time Projection Chamber) experiment at PEP will have a two meter inside diameter superconducting magnet which creatests a 1.5 T uniform solenoidal field for the TPC. The superconducting magnet coil, cryostat, cooling system, and the TPC gas pressure vessel (which operatests at 11 atm) were designed to be about two thirds of a radiation length thick. As a result, a high current density coil design was chosen. The magnet is cooled by forced flow two phase helium. The TPC magnet is the largest adiabatically stable superconducting magnet built to date. The paper presents the parameters of the TPC thin solenoid and its subsystems. Tests results from the Spring 1980 cryogenic tes are presented. The topics to be dealt with in the paper are cryogenic services and the tests of magnet subsystems such as the folded current leads. Large thin superconducting magnet technology will be important to large detectors to be used on LEP

Strange particle measurements from the EOS TPC

International Nuclear Information System (INIS)

Justice, M.

1995-02-01

A high statistics sample of Λ's produced in 2 GeV/nucleon 5 8Ni + nat Cu collisions has been obtained with the EOS Time Projection Chamber at the Bevalac. The coverage of the EOS TPC is essentially 100% for y > y cm and extends down to P T = 0 where interesting effects such as collective radial expansion may be important. In addition, the detection of a majority of the charged particles in the TPC, along with the presence of directed flow for protons and heavier fragments at this beam energy, allows for the correlation of A production with respect to the event reaction plane. Our preliminary analysis indicates the first observation of a sidewards flow signature for A's. Comparisons with the cascade code ARC are made

Development of Micromegas-like gaseous detectors using a pixel readout chip as collecting anode

International Nuclear Information System (INIS)

Chefdeville, M.

2009-01-01

This thesis reports on the fabrication and test of a new gaseous detector with a very large number of readout channels. This detector is intended for measuring the tracks of charged particles with an unprecedented sensitivity to single electrons of almost 100 %. It combines a metal grid for signal amplification called the Micromegas with a pixel readout chip as signal collecting anode and is dubbed GridPix. GridPix is a potential candidate for a sub-detector at a future electron linear collider (ILC) foreseen to work in parallel with the LHC around 2020--2030. The tracking capability of GridPix is best exploited if the Micromegas is integrated on the pixel chip. This integrated grid is called InGrid and is precisely fabricated by wafer post-processing. The various steps of the fabrication process and the measurements of its gain, energy resolution and ion back-flow property are reported in this document. Studies of the response of the complete detector formed by an InGrid and a TimePix pixel chip to X-rays and cosmic particles are also presented. In particular, the efficiency for detecting single electrons and the point resolution in the pixel plane are measured. Implications for a GridPix detector at ILC are discussed. (author)

Free electron lifetime achievements in Liquid Argon Imaging TPC

CERN Document Server

Baibussinov, B; Calligarich, E; Centro, S; Cieslik, K; Farnese, C; Fava, A; Gibin, D; Guglielmi, A; Meng, G; Pietropaolo, F; Rubbia, C; Varanini, F; Ventura, S

2010-01-01

A key feature for the success of the Liquid Argon TPC technology is the industrial purification against electro-negative impurities, especially Oxygen and Nitrogen remnants, which have to be initially and continuously kept at an exceptional purity. New purification techniques have been applied to a 120 litres LAr-TPC test facility in the INFN-LNL laboratory. Through-going muon tracks have been used to monitor the LAr purity. The short path length used (30 cm) is compensated by the high accuracy in the observation of the specific ionization of cosmic rays muons at sea level. A free electron lifetime of (21.4+7.3-4.3) ms, namely > 15.8 ms at 90 % C.L. has been observed under stable conditions over several weeks, corresponding to about 15 ppt (part per trillion) of Oxygen equivalent. At 500 V/cm, where the electron speed is approximately of 1.5 mm/us, the free electron lifetime >15 ms corresponds to an attenuation <15 % for a drift path of 5 m, opening the way to reliable operation of LAr TPC for exceptionall...

Electronic Devices for Controlling the Very High Voltage in the ALICE TPC Detector

CERN Document Server

Boccioli, Marco

2007-01-01

The Time Projection Chamber (TPC) is the core of the ALICE experiment at CERN. The TPC Very High Voltage project covers the development of the control system for the power supply that generates the 100kV necessary for the drift field in the TPC. This paper reports on the project progress, introducing the control system architecture from the electronics up to the control level. All the electronic devices will be described, highlighting their communication issues, and the challenges in integrating these devices in a PLC-based control system.

Simulation and Calibration of the ALICE TPC including innovative Space Charge Calculations

CERN Document Server

Rossegger, S; Riegler, W; Betev, L

2009-01-01

ALICE is one of the four main particle detectors located around the LHC accelerator at CERN. It is particularly designed to study the physics of the quark-gluon plasma by means of nucleus--nucleus collisions at center-of-mass energies up to 5.5 TeV per nucleon pair. A Time-Projection Chamber (TPC) was chosen to be its central-sub-detector due to its low mass properties and its capabilities to provide a robust and accurate Particle Identification even within ultra-high multiplicity environments (up to 8000 tracks per unit of eta). To achieve the required physics performance, the space point resolution of the TPC must be in the order of 0.2 mm. Due to its gigantic size of 5~m in diameter and 5~m in length, corrections for static as well as dynamic effects are indispensable in order to accomplish the design goal. The research presented covers all major issues relevant for the final calibration and therefore the enhancement of the TPC performance in terms of resolution. The main focus was to distinguish between t...

The development of Micromegas for high particle-flux environments

International Nuclear Information System (INIS)

Giomataris, Y.; Mangeot, Ph.; Rebourgeard, Ph.; Robert, J.P.

1996-01-01

Detectors able to operate in high rate environments, with particle flux beyond 10 14 particles/mm 2 /s, are needed for future high energy physics projects and medical radiography. A new promising technique called Micromegas has been proposed. It consists of a 2-stage parallel-plate avalanche chamber of small amplification gap (100 μm) combined with a conversion-drift space. In this paper we present results obtained with such a detector and we see that the detector combines most of the qualities required for high-rate position-sensitive particle detection, particularly it shows excellent spatial and energy resolutions. (author)

Data links for the EOS TPC

International Nuclear Information System (INIS)

Bieser, F.; Jones, R.; McParland, C.

1991-01-01

This paper reports on the design and performance of high speed data links and slower configuration control links used between the EOS TPC detector and the data processing electronics. Data rates of 5 MBytes/link are maintained over 30m with optical isolation. Pedestal subtraction, hit detection, and data reordering are performed online

Quality control of a 2 m{sup 2} Micromegas detector for the ATLAS muon spectrometer upgrade project using contact CCDs

Energy Technology Data Exchange (ETDEWEB)

Biebel, Otmar; Hertenberger, Ralf; Wagner-Kuhr, Jeannine [LMU, Munich (Germany); Wellenstein, Hermann [Brandeis University, Waltham (United States)

2016-07-01

The inner endcap region of the ATLAS muon spectrometer, the Small Wheel, will be upgraded in 2019 using Micromegas detectors to retain the tracking performance after the LHC luminosity upgrade. In the new Small Wheel Micromegas detectors will be arranged in trapezoidal quadruplets of four active layers each and 2-3 m{sup 2} in size. Guaranteeing the design spatial resolution of 100 μm poses a huge challenge for the mechanical precision of each readout plane and the alignment between the 4 planes. We report about a novel optical alignment tool based on Contact CCDs and coded masks which will be used for the quality control during the construction of the Micromegas detectors. Using pictures of an arbitrary cutout of a coded mask on a readout board taken by a Contact CCD the relative position of the mask with respect to the center of the Contact-CCD can be determined on sub μm accuracy. Together with a calibrated reference device the position of masks within a single plane but also within a quadruplet can be measured with high precision allowing to monitor the relative position of the 3 PowerCircuitBoards within a single plane and the relative alignment between the different planes in a quadruplet. In this presentation the ideas of this new optical alignment tool are shown as well as first quality control studies using a Contact-CCD.

Track reconstruction of normal muon decays in the LAMPF TPC: one working scheme

International Nuclear Information System (INIS)

McKee, R.J.

1983-01-01

A working scheme for track reconstruction of normal muon decays in the LAMPF TPC is here outlined. Muon tracks stopping in the TPC and helical electron tracks from muon decay are both identified and fitted for complete event reconstruction. Because of certain geometrical characteristics of the TPC, novel techniques are deployed to find the tracks. Normal road tracing methods do not work reliably; they are replaced by, among other things, a random search technique that locates the helix's planar projection and a carefully worked-out method for correctly putting each coordinate on its proper turn in the helix

Inbetriebnahme und Kalibrierung der ALICE-TPC

CERN Document Server

Wiechula, Jens

2008-01-01

ALICE (A Large Ion Collider Experiment), is the dedicated heavy-ion experiment at the Large Hadron Collider (LHC) at CERN. It is optimised to reconstruct and identify the particles created in a lead-lead collision with a centre of mass energy of 5.5TeV. The main tracking detector is a large-volume time-projection chamber (TPC). With an active volume of about 88m^3 and a total readout area of 32.5m^2 it is the most challenging TPC ever build. A central electrode divides the 5m long detector into two drift regions. Each readout side is subdivided into 18 inner and 18 outer multi-wire proportional read-out chambers. The readout area is subdivide into 557568 pads, where each pad is read out by and electronics chanin. A complex calibration is needed in order to reach the design position-resolution of the reconstructed particle tracks of about 200um. One part of the calibration lies in understanding the electronic-response. The work at hand presents results of the pedestal and noise behaviour of the front-end elect...

The ALICE TPC front end electronics

CERN Document Server

Musa, L; Bialas, N; Bramm, R; Campagnolo, R; Engster, Claude; Formenti, F; Bonnes, U; Esteve-Bosch, R; Frankenfeld, Ulrich; Glässel, P; Gonzales, C; Gustafsson, Hans Åke; Jiménez, A; Junique, A; Lien, J; Lindenstruth, V; Mota, B; Braun-Munzinger, P; Oeschler, H; Österman, L; Renfordt, R E; Ruschmann, G; Röhrich, D; Schmidt, H R; Stachel, J; Soltveit, A K; Ullaland, K

2004-01-01

In this paper we present the front end electronics for the time projection chamber (TPC) of the ALICE experiment. The system, which consists of about 570000 channels, is based on two basic units: (a) an analogue ASIC (PASA) that incorporates the shaping-amplifier circuits for 16 channels; (b) a mixed-signal ASIC (ALTRO) that integrates 16 channels, each consisting of a 10-bit 25-MSPS ADC, the baseline subtraction, tail cancellation filter, zero suppression and multi-event buffer. The complete readout chain is contained in front end cards (FEC), with 128 channels each, connected to the detector by means of capton cables. A number of FECs (up to 25) are controlled by a readout control unit (RCU), which interfaces the FECs to the data acquisition (DAQ), the trigger, and the detector control system (DCS) . A function of the final electronics (1024 channels) has been characterized in a test that incorporates a prototype of the ALICE TPC as well as many other components of the final set-up. The tests show that the ...

GEM Foil Quality Assurance For The ALICE TPC Upgrade

Science.gov (United States)

Brücken, Erik; Hildén, Timo

2018-02-01

The ALICE (A Large Ion Collider Experiment) experiment at the Large Hadron Collider (LHC) at CERN is dedicated to heavy ion physics to explore the structure of strongly interacting matter. The Time Projection Chamber (TPC) of ALICE is a tracking detector located in the central region of the experiment. It offers excellent tracking capabilities as well as particle identification. After the second long shutdown (LS2) the LHC will run at substantially higher luminosities. To be able to increase the data acquisition rate by a factor of 100, the ALICE TPC experiment has to replace the Multi-Wire Proportional Chamber (MWPC) -based readout chambers. The MWPC are operated with gating grid that limits the rate to O(kHz). The new ReadOut Chamber (ROC) design is based on Gas Electron Multiplier (GEM) technology operating in continuous mode. The current GEM productions scheme foresees the production of more than 800 GEM foils of different types. To fulfill the requirements on the performance of the GEM TPC readout, necessitates thorough Quality Assurance (QA) measures. The QA scheme, developed by the ALICE collaboration, will be presented in detail.

GEM Foil Quality Assurance For The ALICE TPC Upgrade

Directory of Open Access Journals (Sweden)

Brücken Erik

2018-01-01

Full Text Available The ALICE (A Large Ion Collider Experiment experiment at the Large Hadron Collider (LHC at CERN is dedicated to heavy ion physics to explore the structure of strongly interacting matter. The Time Projection Chamber (TPC of ALICE is a tracking detector located in the central region of the experiment. It offers excellent tracking capabilities as well as particle identification. After the second long shutdown (LS2 the LHC will run at substantially higher luminosities. To be able to increase the data acquisition rate by a factor of 100, the ALICE TPC experiment has to replace the Multi-Wire Proportional Chamber (MWPC –based readout chambers. The MWPC are operated with gating grid that limits the rate to O(kHz. The new ReadOut Chamber (ROC design is based on Gas Electron Multiplier (GEM technology operating in continuous mode. The current GEM productions scheme foresees the production of more than 800 GEM foils of different types. To fulfill the requirements on the performance of the GEM TPC readout, necessitates thorough Quality Assurance (QA measures. The QA scheme, developed by the ALICE collaboration, will be presented in detail.

Data links for the EOS TPC

International Nuclear Information System (INIS)

Bieser, F.; Jones, R.; McParland, C.

1990-10-01

We report on the design and performance of high speed data links and slower configuration control links used between the EOS TPC detector and the data processing electronics. Data rates of 5MBytes/s/link are maintained over 30m with optical isolation. Pedestal subtraction, hit detection, and data reordering are performed online. 3 refs., 1 fig

Tokamak plasma power balance calculation code (TPC code) outline and operation manual

International Nuclear Information System (INIS)

Fujieda, Hirobumi; Murakami, Yoshiki; Sugihara, Masayoshi.

1992-11-01

This report is a detailed description on the TPC code, that calculates the power balance of a tokamak plasma according to the ITER guidelines. The TPC code works on a personal computer (Macintosh or J-3100/ IBM-PC). Using input data such as the plasma shape, toroidal magnetic field, plasma current, electron temperature, electron density, impurities and heating power, TPC code can determine the operation point of the fusion reactor (Ion temperature is assumed to be equal to the electron temperature). Supplied flux (Volt · sec) and burn time are also estimated by coil design parameters. Calculated energy confinement time is compared with various L-mode scaling laws and the confinement enhancement factor (H-factor) is evaluated. Divertor heat load is predicted by using simple scaling models (constant-χ, Bohm-type-χ and JT-60U empirical scaling models). Frequently used data can be stored in a 'device file' and used as the default values. TPC code can generate 2-D mesh data and the POPCON plot is drawn by a contour line plotting program (CONPLT). The operation manual about CONPLT code is also described. (author)

CCD's at TPC

International Nuclear Information System (INIS)

Zeller, M.E.

1977-01-01

The CCD, Charge Coupled Device, is an analog shift register for which application to the readout of particle detectors has recently been realized. These devices can be used to detect optical information directly, providing an automated readout for streamer or other optical chambers, or as a single input shift register, acting in this instance as a delay line for analog information. A description is given of the latter mode of operation and its utility as a readout method for drift chambers. Most of the information contained herein has been obtained from tests performed in connection with PEP TPC project, PEP-4. That detector will employ approximately 10 4 CCD's making it a reasonable testing ground for ISABELLE size detectors

AGS silicon gold collisions measured in the E-810 TPC

International Nuclear Information System (INIS)

Love, W.A.; Etkin, A.; Foley, K.J.; Hackenburg, R.W.; Longacre, R.S.; Morris, T.W.; Platner, E.D.; Saulys, A.C.; Bonner, B.E.; Buchanan, J.A.; Chiou, C.N.; Clement, J.M.; Corcoran, M.D.; Kruk, J.W.; Miettinen, H.E.; Mutchler, G.S.; Nessi, M.; Nessi-Tedaldi, F.; Roberts, J.B.; Chan, C.S.; Kramer, M.A.; Hallman, T.J.; Madansky, L.; Lindenbaum, S.J.

1990-01-01

The tracking detector of AGS Experiment 810 is a three-piece Time Projection Chamber (TPC) intended to measure all charged tracks in the forward hemisphere of the nucleon-nucleon center of mass system, i.e. forward of an angle of about 20 degrees in the lab. Each module of the TPC contains twelve rows of short anode wires which give 3-D space points on each track, but no dE/dx information useable for particle identification. The TPC was operated in a beam of silicon ions at the end of June 1989 and this talk reports the results of analysis of the data taken with a thin gold target in that run. The authors have gathered a similar amount of data from thin copper and silicon targets, the analysis of which is in a less advanced state. The results of the investigation of the neutral strange particle decays appear in a separate contribution by Al Saulys. This paper presents the current state of the analysis of the charged tracks from the silicon gold collisions

Construction and testing of the two meter diameter TPC thin superconducting solenoid

International Nuclear Information System (INIS)

Green, M.A.; Eberhard, P.H.; Ross, R.R.; Taylor, J.D.

1979-08-01

High energy colliding beam physics often requires large detectors which contain large volumes of magnetic field. The TPC (Time Projection Chamber) experiment at PEP will use a 1.5T magnetic field within a cylindrical volume which is 2.04m in diameter bounded by iron poles which are separated by a gap of 3.25m. The TPC magnet, built in 1979 by the Lawrence Berkeley Laboratory (LBL), is the largest high current density superconducting magnet built to date. It is designed to operate at a current density of 7 x 10 8 Am -2 and a stored energy of 11MJ, and it is protected by shorted secondary windings during a quench. The paper describes the basic parameters of the TPC magnet and the results of the first subassembly tests at LBL

Gaseous time projection chambers for rare event detection: results from the T-REX project. I. Double beta decay

Energy Technology Data Exchange (ETDEWEB)

Irastorza, I.G.; Aznar, F.; Castel, J., E-mail: igor.irastorza@cern.ch, E-mail: faznar@unizar.es, E-mail: jfcastel@unizar.es [Grupo de Física Nuclear y Astropartículas, Departamento de Física Teórica, Universidad de Zaragoza, C/ P. Cerbuna 12, Zaragoza, 50009 (Spain); and others

2016-01-01

As part of the T-REX project, a number of R and D and prototyping activities have been carried out during the last years to explore the applicability of gaseous Time Projection Chambers (TPCs) with Micromesh Gas Structures (Micromegas) in rare event searches like double beta decay, axion research and low-mass WIMP searches. In both this and its companion paper, we compile the main results of the project and give an outlook of application prospects for this detection technique. While in the companion paper we focus on axions and WIMPs, in this paper we focus on the results regarding the measurement of the double beta decay (DBD) of {sup 136}Xe in a high pressure Xe (HPXe) TPC. Micromegas of the microbulk type have been extensively studied in high pressure Xe and Xe mixtures. Particularly relevant are the results obtained in Xe + trimethylamine (TMA) mixtures, showing very promising results in terms of gain, stability of operation, and energy resolution at high pressures up to 10 bar. The addition of TMA at levels of ∼ 1% reduces electron diffusion by up to a factor of 10 with respect to pure Xe, improving the quality of the topological pattern, with a positive impact on the discrimination capability. Operation with a medium size prototype of 30 cm diameter and 38 cm of drift (holding about 1 kg of Xe at 10 bar in the fiducial volume, enough to contain high energy electron tracks in the detector volume) has allowed to test the detection concept in realistic experimental conditions. Microbulk Micromegas are able to image the DBD ionization signature with high quality while, at the same time, measuring its energy deposition with a resolution of at least a ∼ 3% FWHM @ Q{sub ββ}. This value was experimentally demonstrated for high-energy extended tracks at 10 bar, and is probably improvable down to the ∼ 1% FWHM levels as extrapolated from low energy events. In addition, first results on the topological signature information (one straggling track ending in two

Lossy compression of TPC data and trajectory tracking efficiency for the ALICE experiment

International Nuclear Information System (INIS)

Nicolaucig, A.; Ivanov, M.; Mattavelli, M.

2003-01-01

In this paper a quasi-lossless algorithm for the on-line compression of the data generated by the Time Projection Chamber (TPC) detector of the ALICE experiment at CERN is described. The algorithm is based on a lossy source code modeling technique, i.e. it is based on a source model which is lossy if samples of the TPC signal are considered one by one; conversely, the source model is lossless or quasi-lossless if some physical quantities that are of main interest for the experiment are considered. These quantities are the area and the location of the center of mass of each TPC signal pulse, representing the pulse charge and the time localization of the pulse. So as to evaluate the consequences of the error introduced by the lossy compression process, the results of the trajectory tracking algorithms that process data off-line after the experiment are analyzed, in particular, versus their sensibility to the noise introduced by the compression. Two different versions of these off-line algorithms are described, performing cluster finding and particle tracking. The results on how these algorithms are affected by the lossy compression are reported. Entropy coding can be applied to the set of events defined by the source model to reduce the bit rate to the corresponding source entropy. Using TPC simulated data according to the expected ALICE TPC performance, the compression algorithm achieves a data reduction in the range of 34.2% down to 23.7% of the original data rate depending on the desired precision on the pulse center of mass. The number of operations per input symbol required to implement the algorithm is relatively low, so that a real-time implementation of the compression process embedded in the TPC data acquisition chain using low-cost integrated electronics is a realistic option to effectively reduce the data storing cost of ALICE experiment

Particle Identification in Jets and High-Multiplicity pp Events with the ALICE TPC

CERN Document Server

AUTHOR|(SzGeCERN)683272; Vogelsang, Werner

The spectra of identified particles in a collision experiment comprise crucial information about the underlying physical processes. The ALICE experiment has powerful Particle IDentification (PID) capabilities, which are unique at the Large Hadron Collider (LHC). In this thesis, a statistical PID method based on the specific energy loss d$E$/d$x$ in the ALICE Time Projection Chamber (TPC) is developed: the TPC Multi-Template Fit (MTF). The MTF allows for the extraction of identified charged particle spectra in a wide momentum range, which extends from about 150 MeV/$c$ to above 20 GeV/$c$. The TPC PID requires a detailed modelling of the TPC d$E$/d$x$ response for momenta above 2-3 GeV/$c$. A framework is developed that allows for the determination of the model parameters and for evaluating the PID information of charged particles. With the MTF, the transverse momentum $p_{\\mathrm{T}}$ spectra of charged pions, kaons and protons at mid-rapidity ($|\\eta| < 0.9$) are measured for pp collisions at $\\sqrt{s}$ ...

Lowering the background level and the energy threshold of Micromegas x-ray detectors for axion searches

CERN Document Server

Iguaz, F J; Aznar, F; Castel, J F; Dafni, T; Davenport, M; Ferrer-Ribas, E; Galan, J; Garcia, J A; Garza, J G; Giomataris, I; Irastorza, I G; Papaevangelou, T; Rodriguez, A; Tomas, A; Vafeiadis, T; Yildiz, S C

2014-01-01

Axion helioscopes search for solar axions by their conversion in x-rays in the presence of high magnetic fields. The use of low background x-ray detectors is an essential component contributing to the sensitivity of these searches. In this work, we review the recent advances on Micromegas detectors used in the CERN Axion Solar Telescope (CAST) and proposed for the future International Axion Observatory (IAXO). The actual setup in CAST has achieved background levels below 10$^{-6}$ keV$^{-1}$ cm$^{-2}$ s$^{-1}$, a factor 100 lower than the first generation of Micromegas detectors. This reduction is based on active and passive shielding techniques, the selection of radiopure materials, offline discrimination techniques and the high granularity of the readout. We describe in detail the background model of the detector, based on its operation at CAST site and at the Canfranc Underground Laboratory (LSC), as well as on Geant4 simulations. The best levels currently achieved at LSC are low than 10$^{-7}$ keV$^{-1}$ ...

TPC track distortions: correction maps for magnetic and static electric inhomogeneities

CERN Document Server

Dydak, F; Nefedov, Y

2003-01-01

Inhomogeneities of the magnetic and electric fields in the active TPC volume lead to displacements of cluster coordinates, and therefore to track distortions. In case of good data taking conditions, the largest effects are expected from the inhomogeneity of the solenoidal magnetic field, and from a distortion of the electric field arising from a high voltage misalignment between the outer and inner field cages. Both effects are stable over the entire HARP data taking. The displacements are large compared to the azimuthal coordinate resolution but can be corrected with sufficient precision, except at small TPC radius. The high voltage misalignment between the outer and inner field cages is identified as the likely primary cause of sagitta distortions of TPC tracks. The position and the length of the target plays an important role. Based on a detailed modelling of the magnetic and static electric field inhomogeneities, precise correction maps for both effects have been calculated. Predictions from the correctio...

Development and construction of a large TPC prototype for the ILC and study of τ polarisation in τ decays with the ILD detector

International Nuclear Information System (INIS)

Schade, Peter

2009-11-01

This thesis presents two studies which have been made in the framework of the detector development for the International Large Detector (ILD). In the preparation phase for the ILD, prototype studies are performed to develop and optimise the sub-detector technologies which will come into operation. Complementary to these hardware studies, expected physics scenarios are being investigated in full detector simulations. These simulations demonstrate the physics potential of the detector concept and are a benchmark for the detector and the accelerator design. The first part of this thesis gives an introduction to the physics questions addressed to the ILC. Also, the machine and the ILD detector concept are presented. The second part is dedicated to the development and the construction to a large Time Projection Chamber (TPC) prototype (LP). A TPC is foreseen as one of ILD's sub-detectors and shall measure the trajectories of charged particles with an accuracy unprecedented by TPCs operated before. The new prototype offers an infrastructure for the development of modern TPC readout structures which can fulfil the required criteria. Before construction, the design plans of the LP have been optimised for a low material budget of the structure and a very homogeneous drift field. During the manufacturing of the LP, experience with construction techniques has been gained for the construction of the ILD TPC. The third part deals with a simulation study for a polarisation measurement of τ leptons in the process e + e - → τ 1 τ 1 → χ 1 0 χ 1 0 ττ. Here, the τ 1 is the supersymmetric partner of the τ lepton. This simulation study shows the feasibility of the measurement in the chosen SUSY scenario and estimates the accuracy to be expected. Both studies address in particular the track reconstruction capabilities of the ILD detector. Conclusions of the discussed studies and an outlook are presented in part IV. (orig.)

Results from tests of the Delphi TPC prototype

International Nuclear Information System (INIS)

Vilanova, D.

1985-01-01

Results from beam tests of a half-scale sector of the Delphi TPC are presented. The spatial resolution is slightly higher than predicted by Monte Carlo simulations, corresponding to an average value of about 300 μm. (orig.)

Development of a GEM-based high rate TPC

Energy Technology Data Exchange (ETDEWEB)

Neubert, Sebastian; Hoeppner, Christian; Ketzer, Bernhard; Weitzel, Quirin; Paul, Stefan; Woerner, Lisa; Konorov, Igor; Mann, Alexander [Technische Universitaet Muenchen, Physik Department E18, Garching (Germany)

2008-07-01

A TPC is considered as the central tracker of the PANDA experiment, which is currently being planned at the new accelerator complex FAIR at Darmstadt. PANDA is designed as an internal target experiment at the antiproton storage ring HESR. The central tracker has to measure particle trajectories over a wide momentum range (0.1-8 GeV/c) from up to 2.10{sup 7} antiproton-proton annihilations/s. The continuous nature of the antiproton beam makes the use of a traditional ion gate impractical. Owing to their intrinsic ion suppression properties, GEM foils are planned as the amplification stage. A small prototype of this GEM-TPC (diameter 200 mm, drift length 77 mm) has been built and characterized with cosmic muons. Results such as spatial resolution, cluster distributions, and diffusion properties are presented in this talk.

Development of a GEM-based TPC for PANDA

Energy Technology Data Exchange (ETDEWEB)

Hoeppner, Christian; Ketzer, Bernhard; Konorov, Igor; Mann, Alexander; Neubert, Sebastian; Paul, Stephan; Weitzel, Quirin; Woerner, Lisa [Technische Universitaet Muenchen, Physik Department E18, 85748 Garching (Germany)

2008-07-01

A TPC is considered as the central tracker of the PANDA experiment, which is currently being planned at the new accelerator complex FAIR at Darmstadt. PANDA is designed as an internal target experiment at the antiproton storage ring HESR. The central tracker has to measure particle trajectories over a wide momentum range (0.1-8 GeV/c) from up to 2.10{sup 7} antiproton-proton annihilations/s. The continuous nature of the antiproton beam makes the use of a traditional ion gate impractical. Owing to their intrinsic ion suppression properties, GEM foils are planned as the amplification stage. A small prototype of this GEM-TPC (diameter 200 mm, drift length 77 mm) has been built and characterized with cosmic muons. Results such as spatial resolution, cluster distributions, and diffusion properties are presented in this talk.

T2K Liquid Argon TPC

Science.gov (United States)

Meregaglia, Anselmo

2006-09-01

A 2 km LAr detector would be an important asset for the T2K experiment since it would play an important part in reducing the systematics and improving the ultimate θ sensitivity. It would also be an important milestone for the LAr TPC technique, providing in-situ R&D and paving the way for future large LAr detectors. Its main features are discussed in this talk.

CERN Summer Student Project Report – Simulation of the Micromegas Detector

CERN Document Server

Soares Ferreira Nunes Teixeira, Sofia Luisa

2015-01-01

My project during the Summer Student Programme at CERN consisted on simulations of the Micromegas (MM) detectors in order to test and characterize them in the presence of contamination by air of the gas mixture. The MM detectors were chosen for the upcoming upgrade of the ATLAS detector. The motivation for this project and the results obtained are here presented. Moreover, the work that should be carried out after this programme as a continuation of this project is also referred. To conclude, final considerations about the project are presented.

Simulation of space-charge effects in an ungated GEM-based TPC

Energy Technology Data Exchange (ETDEWEB)

Böhmer, F.V., E-mail: felix.boehmer@tum.de; Ball, M.; Dørheim, S.; Höppner, C.; Ketzer, B.; Konorov, I.; Neubert, S.; Paul, S.; Rauch, J.; Vandenbroucke, M.

2013-08-11

A fundamental limit to the application of Time Projection Chambers (TPCs) in high-rate experiments is the accumulation of slowly drifting ions in the active gas volume, which compromises the homogeneity of the drift field and hence the detector resolution. Conventionally, this problem is overcome by the use of ion-gating structures. This method, however, introduces large dead times and restricts trigger rates to a few hundred per second. The ion gate can be eliminated from the setup by the use of Gas Electron Multiplier (GEM) foils for gas amplification, which intrinsically suppress the backflow of ions. This makes the continuous operation of a TPC at high rates feasible. In this work, Monte Carlo simulations of the buildup of ion space charge in a GEM-based TPC and the correction of the resulting drift distortions are discussed, based on realistic numbers for the ion backflow in a triple-GEM amplification stack. A TPC in the future P{sup ¯}ANDA experiment at FAIR serves as an example for the experimental environment. The simulations show that space charge densities up to 65 fC cm{sup −3} are reached, leading to electron drift distortions of up to 10 mm. The application of a laser calibration system to correct these distortions is investigated. Based on full simulations of the detector physics and response, we show that it is possible to correct for the drift distortions and to maintain the good momentum resolution of the GEM-TPC.

Simulation of space-charge effects in an ungated GEM-based TPC

International Nuclear Information System (INIS)

Böhmer, F.V.; Ball, M.; Dørheim, S.; Höppner, C.; Ketzer, B.; Konorov, I.; Neubert, S.; Paul, S.; Rauch, J.; Vandenbroucke, M.

2013-01-01

A fundamental limit to the application of Time Projection Chambers (TPCs) in high-rate experiments is the accumulation of slowly drifting ions in the active gas volume, which compromises the homogeneity of the drift field and hence the detector resolution. Conventionally, this problem is overcome by the use of ion-gating structures. This method, however, introduces large dead times and restricts trigger rates to a few hundred per second. The ion gate can be eliminated from the setup by the use of Gas Electron Multiplier (GEM) foils for gas amplification, which intrinsically suppress the backflow of ions. This makes the continuous operation of a TPC at high rates feasible. In this work, Monte Carlo simulations of the buildup of ion space charge in a GEM-based TPC and the correction of the resulting drift distortions are discussed, based on realistic numbers for the ion backflow in a triple-GEM amplification stack. A TPC in the future P ¯ ANDA experiment at FAIR serves as an example for the experimental environment. The simulations show that space charge densities up to 65 fC cm −3 are reached, leading to electron drift distortions of up to 10 mm. The application of a laser calibration system to correct these distortions is investigated. Based on full simulations of the detector physics and response, we show that it is possible to correct for the drift distortions and to maintain the good momentum resolution of the GEM-TPC

Design and Construction of Large Size Micromegas Chambers for the ATLAS Upgrade of the Muon Spectrometer

Energy Technology Data Exchange (ETDEWEB)

NONE

2015-07-01

Large area Micromegas detectors will be employed for the first time in high-energy physics experiments. A total surface of about 150 m{sup 2} of the forward regions of the Muon Spectrometer of the ATLAS detector at LHC will be equipped with 8-layer Micromegas modules. Each module extends over a surface from 2 to 3 m{sup 2} for a total active area of 1200 m{sup 2}. Together with the small strip Thin Gap Chambers they will compose the two New Small Wheels, which will replace the innermost stations of the ATLAS end-cap muon tracking system in the 2018/19 shutdown. In order to achieve a 15% transverse momentum resolution for 1 TeV muons, in addition to an excellent intrinsic resolution, the mechanical precision of each plane of the assembled module must be as good as 30 μm along the precision coordinate and 80 μm perpendicular to the chamber. In the prototyping towards the final configuration two similar quadruplets with dimensions 1.2 x 0.5 m{sup 2} have been built with the same structure as foreseen for the NSW upgrade. It represents the first example of a Micromegas quadruplet ever built, realized using the resistive-strip technology and decoupling the amplification mesh from the readout structure. All readout planes are segmented into strips with a pitch of 400 μm for a total of 4096 strips. In two of the four planes the strips are inclined by 1.5 deg. and provide a measurement of the second coordinate. The design and construction procedure of the Micromegas modules will be presented, as well as the design for the assembly of modules onto the New Small Wheel. Emphasis will be given on the methods developed to achieve the challenging mechanical precision. Measurements of deformation on chamber prototypes as a function of thermal gradients, gas over-pressure and internal stress (mesh tension and module fixation on supports) will be also shown in comparison to simulation. These tests were essential in the development of the final design in order to minimize the

A new Micromegas line for the CAST experiment

International Nuclear Information System (INIS)

Andriamonje, Samuel; Aune, Stephan; Braeuninger, Heinrich; Dafni, Theopisti; Dogan, Berkol; Fanourakis, George; Ferrer Ribas, Esther; Galan, Javier; Geralis, Theodoros; Giganon, Arnaud; Giomataris, Ioannis; Irastorza, Igor G.; Kousouris, Konstantinos; Morales, Julio; Philippe Mols, Jean; Papaevangelou, Thomas; Pivovaroff, Mike; Riallot, Marc; Ruz, Jaime; Soufli, Regina

2007-01-01

A low background Micromegas detector has been operating on the Cern Axion Solar Telescope (CAST) experiment at CERN for the search of solar axions during the first phase of the experiment. The detector operated efficiently and achieved a very low level of background rejection (5x10 -5 countskeV -1 cm -2 s -1 ) thanks to its good spatial and energy resolution as well as the low radioactivity materials used in the construction of the detector. For the second phase of the experiment, the detector is being upgraded by adding a shielding and including focusing optics. These improvements should allow for a background rejection better than two orders of magnitude. The preliminary results of the first tests in the laboratory and in the PANTER X-ray test facility will be shown

Using Micromegas in ATLAS to Monitor the Luminosity

CERN Document Server

The ATLAS collaboration

2013-01-01

Five small prototype micromegas detectors were positioned in the ATLAS detector during LHC running at $\\sqrt{s} = 8\\, \\mathrm{TeV}$. A $9\\times 4.5\\, \\mathrm{cm^2}$ two-gap detector was placed in front of the electromagnetic calorimeter and four $9\\times 10\\, \\mathrm{cm^2}$ detectors on the ATLAS Small Wheels, the first station of the forward muon spectrometer. The one attached to the calorimeter was exposed to interaction rates of about $70\\,\\mathrm{kHz/cm^2}$ at ATLAS luminosity $\\mathcal{L}=5\\times 10^{33}\\,\\mathrm{cm^{-2}s^{-1}}$ two orders of magnitude higher than the rates in the Small Wheel. We compare the currents drawn by the detector installed in front of the electromagnetic calorimeter with the luminosity measurement in ATLAS experiment.

Heavy ion reaction measurements with the EOS TPC (looking for central collisions with missing energy)

International Nuclear Information System (INIS)

Wieman, H.H.

1994-05-01

The EOS TPC was constructed for complete event measurement of heavy ion collisions at the Bevalac. We report here on the TPC design and some preliminary measurements of conserved event quantities such as total invariant mass, total momentum, total A and Z

A continuous read-out TPC for the ALICE upgrade

Energy Technology Data Exchange (ETDEWEB)

Lippmann, C., E-mail: C.Lippmann@gsi.de

2016-07-11

The largest gaseous Time Projection Chamber (TPC) in the world, the ALICE TPC, will be upgraded based on Micro Pattern Gas Detector technology during the second long shutdown of the CERN Large Hadron Collider in 2018/19. The upgraded detector will operate continuously without the use of a triggered gating grid. It will thus be able to read all minimum bias Pb–Pb events that the LHC will deliver at the anticipated peak interaction rate of 50 kHz for the high luminosity heavy-ion era. New read-out electronics will send the continuous data stream to a new online farm at rates up to 1 TByte/s. A fractional ion feedback of below 1% is required to keep distortions due to space charge in the TPC drift volume at a tolerable level. The new read-out chambers will consist of quadruple stacks of Gas Electron Multipliers (GEM), combining GEM foils with a different hole pitch. Other key requirements such as energy resolution and operational stability have to be met as well. A careful optimisation of the performance in terms of all these parameters was achieved during an extensive R&D program. A working point well within the design specifications was identified with an ion backflow of 0.63%, a local energy resolution of 11.3% (sigma) and a discharge probability comparable to that of standard triple GEM detectors.

T2K Liquid Argon TPC

International Nuclear Information System (INIS)

Meregaglia, Anselmo

2006-01-01

A 2 km LAr detector would be an important asset for the T2K experiment since it would play an important part in reducing the systematics and improving the ultimate θ 13 sensitivity. It would also be an important milestone for the LAr TPC technique, providing in-situ R and D and paving the way for future large LAr detectors. Its main features are discussed in this talk

arXiv GEM Foil Quality Assurance For The ALICE TPC Upgrade

CERN Document Server

INSPIRE-00019412; Hildén, Timo

2018-01-01

The ALICE (A Large Ion Collider Experiment) experiment at the Large Hadron Collider (LHC) at CERN is dedicated to heavy ion physics to explore the structure of strongly interacting matter. The Time Projection Chamber (TPC) of ALICE is a tracking detector located in the central region of the experiment. It offers excellent tracking capabilities as well as particle identification. After the second long shutdown (LS2) the LHC will run at substantially higher luminosities. To be able to increase the data acquisition rate by a factor of 100, the ALICE TPC experiment has to replace the Multi-Wire Proportional Chamber (MWPC) –based readout chambers. The MWPC are operated with gating grid that limits the rate to O(kHz). The new ReadOut Chamber (ROC) design is based on Gas Electron Multiplier (GEM) technology operating in continuous mode. The current GEM productions scheme foresees the production of more than 800 GEM foils of different types. To fulfill the requirements on the performance of the GEM TPC readout, nec...

Construction and quality assurance of large area resistive strip Micromegas for the upgrade of the ATLAS Muon Spectrometer at LHC/CERN

Science.gov (United States)

Lösel, P.

2017-06-01

Large area Micromegas detectors will be employed for the first time in high-energy physics experiments. To cope with increasing background rates, associated with the steadily increasing luminosity of LHC to 10 times design luminosity, the present detector technology in the current innermost stations of the muon endcap system of the ATLAS experiment (the Small Wheel), will be replaced in 2019/2020 by resistive strip Micromegas and small strip TGC detectors. Both technologies will provide tracking and trigger information. In the "New Small Wheel" the Micromegas will be arranged in eight detection layers built of trapezoidally shaped quadruplets of four different sizes covering in total about 1200 m2 of detection plane. In order to achieve 15 % transverse momentum resolution for 1 TeV muons, a challenging mechanical precision is required in the construction of each active plane, with an alignment of the readout strips at the level of 30 μm RMS along the precision coordinate and 80 μm RMS perpendicular to the plane. Each individual Micromegas plane must achieve a spatial resolution better than 100 μm at background rates up to 15 kHz/cm2 while being operated in an inhomogeneous magnetic field (B <= 0.3 T). The required mechanical precision for the production of the components and their assembly, on such large area detectors, is a key point and must be controlled during construction and integration. Particularly the alignment of the readout strips within a quadruplet appears to be demanding. The readout strips are etched on PCB boards using photolithographic processes. Depending on the type of the module, 3 or 5 PCB boards need to be joined and precisely aligned to form a full readout plane. The precision in the alignment is reached either by use of precision mechanical holes or by optical masks, both referenced to the strip patterns. Assembly procedures have been developed to build the single panels with the required mechanical precision and to assemble them in a

Quality control and quality assurance of micromegas readout boards for the ATLAS New Small Wheel

CERN Document Server

Nanda, Amit

2016-01-01

The resistive anode boards of the Micromegas detectors for ATLAS NSW upgrade, will be produced in industries. The anode boards will be thoroughly evaluated at CERN following a detailed quality control and quality assurance (QA/QC) procedure. The report describes thoroughly the procedures and the design of a small QC tool for easier measurements of electrical properties of the readout boards.

Upgrade of the TAMU MDM-focal plane detector with MicroMegas technology

Energy Technology Data Exchange (ETDEWEB)

Spiridon, A., E-mail: aspiridon@comp.tamu.edu [Cyclotron Institute, Texas A& M University, College Station, TX 77843 (United States); Pollacco, E. [IRFU, CEA Saclay, Gif-sur-Yvette (France); Roeder, B.T.; Saastamoinen, A.; Chyzh, R.; Dag, M.; Tribble, R.E. [Cyclotron Institute, Texas A& M University, College Station, TX 77843 (United States); Trache, L.; Pascovici, G. [National Institute of Physics and Nuclear Engineering, Bucharest-Magurele RO-077125 (Romania); De Oliveira, R. [CERN, Geneva (Switzerland)

2016-06-01

A gridded ionization chamber used as a focal plane detector at the back of the TAMU-MDM spectrometer was modified to use MicroMegas technology for the purpose of improving energy resolution and particle identification. The upgraded system was tested in experimental conditions with several heavy-ion beams at 12 MeV/u and found to achieve resolutions between 3.2% and 4.8%. This is a significant improvement over the previous performance of 10–15% obtained using the existing, conventional ionization chambers.

Upgrade of the TAMU MDM-focal plane detector with MicroMegas technology

International Nuclear Information System (INIS)

Spiridon, A.; Pollacco, E.; Roeder, B.T.; Saastamoinen, A.; Chyzh, R.; Dag, M.; Tribble, R.E.; Trache, L.; Pascovici, G.; De Oliveira, R.

2016-01-01

A gridded ionization chamber used as a focal plane detector at the back of the TAMU-MDM spectrometer was modified to use MicroMegas technology for the purpose of improving energy resolution and particle identification. The upgraded system was tested in experimental conditions with several heavy-ion beams at 12 MeV/u and found to achieve resolutions between 3.2% and 4.8%. This is a significant improvement over the previous performance of 10–15% obtained using the existing, conventional ionization chambers.

Some TPC [Time Projection Chamber] measurements in an oxygen beam at the AGS

International Nuclear Information System (INIS)

Love, W.A.; Bonner, B.E.; Buchanan, J.A.

1988-01-01

The principal detector for AGS Experiment 810 is a Time Projection Chamber (TPC) in which it is intended to measure momenta and angles of a major fraction of the charged particles from each light ion collision. This report describes the results of a test of a prototype of the TPC in a beam of (14.6 /times/ 16 = 233.6 GeV/c) oxygen ions run in June of this year

Building a large-area GEM-based readout chamber for the upgrade of the ALICE TPC

CERN Document Server

Gasik, Piotr

2017-01-01

A large Time Projection Chamber (TPC) is the main device for tracking and charged-particle identification in the ALICE experiment at the CERN LHC. After the second long shutdown in 2019-2020, the LHC will deliver Pb beams colliding at an interaction rate up to 50 kHz, which is about a factor of 100 above the present read-out rate of the TPC. To fully exploit the LHC potential the TPC will be upgraded based on the Gas Electron Multiplier (GEM) technology. A prototype of an ALICE TPC Outer Read-Out Chamber (OROC) was equipped with twelve large-size GEM foils as amplification stage to demonstrate the feasibility of replacing the current Multi Wire Proportional Chambers with the new technology. With a total area of $\\sim$0.76 m$^2$ it is the largest GEM-based detector built to date. The GEM OROC was installed within a test field cage and commissioned with radioactive sources.

Building a large-area GEM-based readout chamber for the upgrade of the ALICE TPC

Energy Technology Data Exchange (ETDEWEB)

Gasik, P. [Physik Department E62, Technische Universität München, Garching (Germany); Excellence Cluster ‘Origin and Structure of the Universe’, Garching (Germany)

2017-02-11

A large Time Projection Chamber (TPC) is the main device for tracking and charged-particle identification in the ALICE experiment at the CERN LHC. After the second long shutdown in 2019–2020, the LHC will deliver Pb beams colliding at an interaction rate up to 50 kHz, which is about a factor of 100 above the present read-out rate of the TPC. To fully exploit the LHC potential the TPC will be upgraded based on the Gas Electron Multiplier (GEM) technology. A prototype of an ALICE TPC Outer Read-Out Chamber (OROC) was equipped with twelve large-size GEM foils as amplification stage to demonstrate the feasibility of replacing the current Multi Wire Proportional Chambers with the new technology. With a total area of ∼0.76 m{sup 2} it is the largest GEM-based detector built to date. The GEM OROC was installed within a test field cage and commissioned with radioactive sources.

Building a large-area GEM-based readout chamber for the upgrade of the ALICE TPC

International Nuclear Information System (INIS)

Gasik, P.

2017-01-01

A large Time Projection Chamber (TPC) is the main device for tracking and charged-particle identification in the ALICE experiment at the CERN LHC. After the second long shutdown in 2019–2020, the LHC will deliver Pb beams colliding at an interaction rate up to 50 kHz, which is about a factor of 100 above the present read-out rate of the TPC. To fully exploit the LHC potential the TPC will be upgraded based on the Gas Electron Multiplier (GEM) technology. A prototype of an ALICE TPC Outer Read-Out Chamber (OROC) was equipped with twelve large-size GEM foils as amplification stage to demonstrate the feasibility of replacing the current Multi Wire Proportional Chambers with the new technology. With a total area of ∼0.76 m 2 it is the largest GEM-based detector built to date. The GEM OROC was installed within a test field cage and commissioned with radioactive sources.

TPC2 polymorphisms associated with a hair pigmentation phenotype in humans result in gain of channel function by independent mechanisms.

Science.gov (United States)

Chao, Yu-Kai; Schludi, Verena; Chen, Cheng-Chang; Butz, Elisabeth; Nguyen, O N Phuong; Müller, Martin; Krüger, Jens; Kammerbauer, Claudia; Ben-Johny, Manu; Vollmar, Angelika M; Berking, Carola; Biel, Martin; Wahl-Schott, Christian A; Grimm, Christian

2017-10-10

Two-pore channels (TPCs) are endolysosomal cation channels. Two members exist in humans, TPC1 and TPC2. Functional roles associated with the ubiquitously expressed TPCs include VEGF-induced neoangiogenesis, LDL-cholesterol trafficking and degradation, physical endurance under fasting conditions, autophagy regulation, the acrosome reaction in sperm, cancer cell migration, and intracellular trafficking of pathogens such as Ebola virus or bacterial toxins (e.g., cholera toxin). In a genome-wide association study for variants associated with human pigmentation characteristics two coding variants of TPC2, rs35264875 (encoding M484L) and rs3829241 (encoding G734E), have been found to be associated with a shift from brown to blond hair color. In two recent follow-up studies a role for TPC2 in pigmentation has been further confirmed. However, these human polymorphic variants have not been functionally characterized until now. The development of endolysosomal patch-clamp techniques has made it possible to investigate directly ion channel activities and characteristics in isolated endolysosomal organelles. We applied this technique here to scrutinize channel characteristics of the polymorphic TPC2 variants in direct comparison with WT. We found that both polymorphisms lead to a gain of channel function by independent mechanisms. We next conducted a clinical study with more than 100 blond- and brown/black-haired individuals. We performed a genotype/phenotype analysis and subsequently isolated fibroblasts from WT and polymorphic variant carriers for endolysosomal patch-clamp experimentation to confirm key in vitro findings.

Design and Construction of Large Size Micromegas Chambers for the ATLAS Upgrade of the Muon Spectrometer

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00380308; The ATLAS collaboration

2016-01-01

Large area Micromegas detectors will be employed for the first time in high-energy physics experiments. A total surface area of about 150 m$^2$ of the forward regions (pseudo-rapidity coverage -- 1.3 $\\boldsymbol{< |\\eta| <}$ 2.7) of the Muon Spectrometer of the ATLAS detector at LHC will be equipped with 8-layer Micromegas modules. Each module extends over a surface from 2 to 3 m$^2$ for a total active area of 1200 m$^2$. Together with the small strip Thin Gap Chambers they will compose the two New Small Wheels (NSW), which will replace the innermost stations of the ATLAS endcap muon tracking system in the 2018/19 shutdown. In order to achieve a 15\\% transverse momentum resolution for 1 TeV muons, in addition to an excellent intrinsic position resolution, the mechanical precision of each plane of the assembled module must be $\\boldsymbol{30{\\mu}m}$ along the precision coordinate and $\\boldsymbol{80{\\mu}m}$ perpendicular to the chamber. All readout planes are segmented into strips with a pitch of $\\bold...

Dysregulation of lysosomal morphology by pathogenic LRRK2 is corrected by TPC2 inhibition.

Science.gov (United States)

Hockey, Leanne N; Kilpatrick, Bethan S; Eden, Emily R; Lin-Moshier, Yaping; Brailoiu, G Cristina; Brailoiu, Eugen; Futter, Clare E; Schapira, Anthony H; Marchant, Jonathan S; Patel, Sandip

2015-01-15

Two-pore channels (TPCs) are endolysosomal ion channels implicated in Ca(2+) signalling from acidic organelles. The relevance of these ubiquitous proteins for human disease, however, is unclear. Here, we report that lysosomes are enlarged and aggregated in fibroblasts from Parkinson disease patients with the common G2019S mutation in LRRK2. Defects were corrected by molecular silencing of TPC2, pharmacological inhibition of TPC regulators [Rab7, NAADP and PtdIns(3,5)P2] and buffering local Ca(2+) increases. NAADP-evoked Ca(2+) signals were exaggerated in diseased cells. TPC2 is thus a potential drug target within a pathogenic LRRK2 cascade that disrupts Ca(2+)-dependent trafficking in Parkinson disease. © 2015. Published by The Company of Biologists Ltd.

Construction and Test of Full-Size Micromegas Modules for the ATLAS New Small Wheel Upgrade

CERN Document Server

Bortfeldt, Jonathan; The ATLAS collaboration

2015-01-01

In 2015 the first full size resistive-strip MicroMegas operational modules for the ATLAS New Small Wheel upgrade will be realized. The goal is to provide precision muon tracking with spatial resolution below 100 μm on trapezoidal detector areas between 2 and 3 m^2. The overall thickness of each detector modules is about 70 mm and the total number of read-out channels is of the order of 10^4. Each module consists of a quadruplet of four MicroMegas with 5 mm drift gaps intervaled with 2 read-out panels with anodes on both sides and 3 drift panels. The panels are realized as 11 mm thick stiffening sandwiches made of 10 mm thick honeycomb, 0.5 mm thick FR4 pcb material sheets as surfaces and aluminium frames. The active part of the read-out anodes consists of horizontal strips with 0.45 mm pitch. Two out of the four anode planes are built with stereo strips of identical pitch and stereo angles of ±1.5 degrees. A sequence of 128 μm height insulating pillars on the read-out planes allows the pretensioned microme...

Live event reconstruction in an optically read out GEM-based TPC

Science.gov (United States)

Brunbauer, F. M.; Galgóczi, G.; Gonzalez Diaz, D.; Oliveri, E.; Resnati, F.; Ropelewski, L.; Streli, C.; Thuiner, P.; van Stenis, M.

2018-04-01

Combining strong signal amplification made possible by Gaseous Electron Multipliers (GEMs) with the high spatial resolution provided by optical readout, highly performing radiation detectors can be realized. An optically read out GEM-based Time Projection Chamber (TPC) is presented. The device permits 3D track reconstruction by combining the 2D projections obtained with a CCD camera with timing information from a photomultiplier tube. Owing to the intuitive 2D representation of the tracks in the images and to automated control, data acquisition and event reconstruction algorithms, the optically read out TPC permits live display of reconstructed tracks in three dimensions. An Ar/CF4 (80/20%) gas mixture was used to maximize scintillation yield in the visible wavelength region matching the quantum efficiency of the camera. The device is integrated in a UHV-grade vessel allowing for precise control of the gas composition and purity. Long term studies in sealed mode operation revealed a minor decrease in the scintillation light intensity.

pesticide residues in water from tpc sugarcane plantations

African Journals Online (AJOL)

ABSTRACT. We report herein, the analysis of water samples collected from TPC Sugarcane Plantation and its environs in Kilimanjaro region, which is the earliest intensive user of pesticides in Tanzania. A total of 50 water samples collected from 18 sampling sites between 2000 and 2001 were analyzed for pesticide ...

Peach Bottom Turbine Trip Simulations with RETRAN Using INER/TPC BWR Transient Analysis Method

International Nuclear Information System (INIS)

Kao Lainsu; Chiang, Show-Chyuan

2005-01-01

The work described in this paper is benchmark calculations of pressurization transient turbine trip tests performed at the Peach Bottom boiling water reactor (BWR). It is part of an overall effort in providing qualification basis for the INER/TPC BWR transient analysis method developed for the Kuosheng and Chinshan plants. The method primarily utilizes an advanced system thermal hydraulics code, RETRAN02/MOD5, for transient safety analyses. Since pressurization transients would result in a strong coupling effect between core neutronic and system thermal hydraulics responses, the INER/TPC method employs the one-dimensional kinetic model in RETRAN with a cross-section data library generated by the Studsvik-CMS code package for the transient calculations. The Peach Bottom Turbine Trip (PBTT) tests, including TT1, TT2, and TT3, have been successfully performed in the plant and assigned as standards commonly for licensing method qualifications for years. It is an essential requirement for licensing purposes to verify integral capabilities and accuracies of the codes and models of the INER/TPC method in simulating such pressurization transients. Specific Peach Bottom plant models, including both neutronics and thermal hydraulics, are developed using modeling approaches and experiences generally adopted in the INER/TPC method. Important model assumptions in RETRAN for the PBTT test simulations are described in this paper. Simulation calculations are performed with best-estimated initial and boundary conditions obtained from plant test measurements. The calculation results presented in this paper demonstrate that the INER/TPC method is capable of calculating accurately the core and system transient behaviors of the tests. Excellent agreement, both in trends and magnitudes between the RETRAN calculation results and the PBTT measurements, shows reliable qualifications of the codes/users/models involved in the method. The RETRAN calculated peak neutron fluxes of the PBTT

WZ di-boson measurements with the ATLAS experiment at the LHC and performance of resistive Micromegas in view of HL-LHC applications

International Nuclear Information System (INIS)

Manjarres-Ramos, Joany

2013-01-01

During the past two years, the CERN Large Hadron Collider (LHC) has performed exceptionally. The data collected by ATLAS made possible the first Standard Model physics measurements and produced a number of important experimental results. In the first part of this document the measurement of the WZ production with the ATLAS detector is presented and the second part is devoted to the study of resistive Micromegas properties, in view of the installation in the ATLAS spectrometer forward regions for the first phase of High Luminosity LHC (HL-LHC). The measurement of the WZ production probes the electroweak sector of the Standard Model at high energies and allows for generic tests for New Physics beyond the Standard Model. Two datasets of LHC proton-proton collisions were analyzed, 4.8 fb -1 of integrated luminosity at center-of-mass energy of 7 TeV, and 13 fb -1 at 8 TeV, collected in 2011 and the first half of 2012 respectively. Fully leptonic decay events are selected with electrons, muons and missing transverse momentum in the final state. Different date-driven estimates of the background were developed in the context of this analysis. The fiducial and total cross section of WZ production are measured and limits on anomalous triple gauge boson couplings are set. The second part of the document is devoted to the upgrade of the ATLAS detector. The conditions at the High Luminosity LHC calls for detectors capable of operating in a flux of collisions and background particles approximately ten times larger compared to today's conditions. The efficiency, resolution and robustness of resistive Micromegas were studied, as part of the R and D project aimed at the construction of large-area spark-resistant muon chambers using the Micromegas technology. (author) [fr

Simulation of double beta decay in the ''SeXe'' TPC

Science.gov (United States)

Mauger, F.

2007-04-01

In 2004, the NEMO collaboration has started some preliminary studies for a next-generation double beta decay experiment: SuperNEMO. The possibility to use a large gaseous TPC has been investigated using simulation and extrapolation of former experiments. In this talk, I report on the reasons why such techniques have not been selected in 2004 and led the NEMO collaboration to reuse the techniques implemented within the NEMO3 detector.

Status of the ALICE TPC upgrade for high-rate operation

Energy Technology Data Exchange (ETDEWEB)

Gasik, Piotr [TU Muenchen, Physik Department E12, Excellence Cluster ' ' Universe' ' , D-85748, Garching (Germany); Collaboration: ALICE-Collaboration

2015-07-01

A large Time Projection Chamber (TPC) is the main device for tracking and charged particle identification in the ALICE experiment at the CERN LHC. After the second long shutdown in 2018/2019, the LHC will deliver Pb beams colliding at an interaction rate of about 50 kHz, which is about a factor of 100 above the present readout rate of the TPC. This will result in a significant improvement on the sensitivity of rare probes that are considered key observables to characterise the hot and dense QCD matter created in such collisions. In order to make full use of this luminosity, a major upgrade of the TPC is required. It is foreseen to replace the existing MWPC-based readout chambers by Gas Electron Multiplier (GEM) detectors to overcome the rate limitations imposed by the present gated readout scheme. An extensive R and D program has been launched to reach the challenging requirements of the upcoming upgrade of the detector. In this presentation the most recent results are discussed concerning ion backflow suppression, gain stability, energy and dE/dx resolution and stability against discharges. The status of the upgrade of the online calibration and data reduction system, which includes advanced techniques for online corrections of space-charge distortions, as well as the development of a new readout electronics are reported.

A Micromegas-based low-background x-ray detector coupled to a slumped-glass telescope for axion research

CERN Document Server

Aznar, F; Christensen, F E; Dafni, T; Decker, T A; Ferrer-Ribas, E; Garcia, J A; Giomataris, I; Gracia, J G; Hailey, C J; Hill, R M; Iguaz, F J; Irastorza, I G; Jakobsen, A C; Luzon, G; Mirallas, H; Papaevangelou, T; Pivovaroff, M J; Ruz, J; Vafeiadis, T; Vogel, J K

2015-01-01

We report on the design, construction and operation of a low background x-ray detection line composed of a shielded Micromegas (micromesh gaseous structure) detector of the microbulk technique. The detector is made from radiopure materials and is placed at the focal point of a $\\sim$~5 cm diameter, 1.3 m focal-length, cone-approximation Wolter I x-ray telescope (XRT) comprised of thermally-formed (or "slumped") glass substrates deposited with multilayer coatings. The system has been conceived as a technological pathfinder for the future International Axion Observatory (IAXO), as it combines two of the techniques (optic and detector) proposed in the conceptual design of the project. It is innovative for two reasons: it is the first time an x-ray optic has been designed and fabricated specifically for axion research, and the first time a Micromegas detector has been operated with an x-ray optic. The line has been installed at one end of the CERN Axion Solar Telescope (CAST) magnet and is currently looking for s...

Aging Analysis of Micromegas Detectors for ATLAS New Small Wheel

CERN Document Server

Quinnan, Melissa

2015-01-01

In preparation for the coming High Luminosity Large Hadron Collider (HL-LHC) upgrade, the New Small Wheel (NSW) will replace the Small Wheel of the ATLAS Muon Spectrometer as part of the 2018 ATLAS Phase-I upgrade. Micromegas (MM) detectors will serve as one component of the NSW. These gaseous micro-mesh detectors will accommodate the higher luminosity and trigger rate of the future HL-LHC.In order to predict performance of MM after several years in the HL-LHC, radiation aging tests were conducted in the Gamma Irradiation Facility (GIF++) using a Cs 137 source. Two small MM prototype "T" chambers were irradiated and studied over the course of several months to accelerate the aging process and characterize chamber behavior. This report outlines a record of the aging process thus far and demonstrates techniques used to describe aging effects, namely measurements of average current, integrated charge, and gain. These will be used in the ongoing aging analysis of the T chambers and in future aging studies of the ...

Design and Construction of Large Size Micromegas Chambers for the ATLAS Upgrade of the Muon Spectrometer

CERN Document Server

Jeanneau, Fabien; The ATLAS collaboration

2015-01-01

Large area Micromegas detectors will be employed for the first time in high-energy physics experiments. A total surface of about 150 m2 of the forward regions of the Muon Spectrometer of the ATLAS detector at LHC will be equipped with 8-layer Micromegas modules. Each module extends over a surface from 2 to 3 m2 for a total active area of 1200 m2. Together with the small strip Thin Gap Chambers they will compose the two New Small Wheels, which will replace the innermost stations of the ATLAS endcap muon tracking system in the 2018/19 shutdown. In order to achieve a 15% transverse momentum resolution for 1 TeV muons, in addition to an excellent intrinsic resolution, the mechanical precision of each plane of the assembled module must be as good as 30 μm along the precision coordinate and 80 μm perpendicular to the chamber. In the prototyping towards the final configuration two similar quadruplets with dimensions 1.2×0.5 m2 have been built with the same structure as foreseen for the NSW upgrade. It represents ...

Design and Construction of Large Size Micromegas Chambers for the ATLAS Upgrade of the Muon Spectrometer

CERN Document Server

Jeanneau, Fabien; The ATLAS collaboration

2015-01-01

Large area Micromegas detectors will be employed for the first time in high-energy physics experiments. A total surface of about 150 m2 of the forward regions of the Muon Spectrometer of the ATLAS detector at LHC will be equipped with 8-layer Micromegas modules. Each module extends over a surface from 2 to 3 m2 for a total active area of 1200 m2. Together with the small strip Thin Gap Chambers they will compose the two New Small Wheels, which will replace the innermost stations of the ATLAS endcap muon tracking system in the 2018/19 shutdown. In order to achieve a 15% transverse momentum resolution for 1 TeV muons, in addition to an excellent intrinsic resolution, the mechanical precision of each plane of the assembled module must be as good as 30 μm along the precision coordinate and 80 μm perpendicular to the chamber. All readout planes are segmented into strips with a pitch of 400 μm for a total of 4096 strips. In two of the four planes the strips are inclined by 1.5 ◦ and provide a measurement of the...

Design and Construction of Large Size Micromegas Chambers for the ATLAS Upgrade of the Muon Spectrometer

CERN Document Server

Losel, Philipp Jonathan; The ATLAS collaboration

2014-01-01

Large area Micromegas detectors will be employed fo r the first time in high-energy physics experiments. A total surface of about 150 m$^2$ of the forward regions of the Muon Spectrometer of the ATLAS detector at LHC will be equipped with 8-layer Micromegas modules. Each module extends over a surface from 2 to 3 m$^2$ for a total active area of 1200 m$^2$. Together with the small strip Thin Gap Chambers they will compose the two New Small Wheels, which will replace the innermost stations of the ATLAS endcap muon tracking system in the 2018/19 shutdown. In order to achieve a 15% transverse momentum resol ution for 1 TeV muons, in addition to an excellent intrinsic resolution, the mechanical prec ision of each plane of the assembled module must be as good as 30 $\\mu$m along the precision coordi nate and 80 $\\mu$m perpendicular to the chamber. The design and construction procedure of the microm egas modules will be presented, as well as the design for the assembly of modules onto the New Small Wheel. Emphasis wi...

Identifying Charged Hadrons on the Relativistic Rise Using the ALICE TPC at LHC

CERN Document Server

Gros, Philippe

2011-01-01

The chain from hadron collisions to the physics results requires several important links. First the outcome of the collision is measured by the detectors. Then, the signal from the detector is processed and transformed into information relevant for the study of the physics processes. The data is made available to physicists to be analysed and used to improve theories. This thesis presents work done on no most of these steps for the ALICE experiment at LHC. First a study of the main processes in the TPC detector for ALICE was done using simulation and test beam data. The results are shown in paper I. The study was deepened with the analysis of test beam data from a TPC prototype for the ILC, as shown in paper III. Concurrently, a study on the Grid – computing framework for distributed computing and storage resources – was performed. This involved the development of an interface module between the ALICE software AliEn and the ARC software developped in the Nordic countries. This work is presented in paper I...

The ICARUS 50 1 LAr TPC in the CERN $\

CERN Document Server

Arneodo, F.; De Mitri, I.; Mazza, D.; Parlati, S.; Petrera, S.; Piano Mortari, Giovanni; Verdecchia, M.; Benetti, P.; Borio Di Tigliole, A.; Calligarich, E.; Cesana, E.; Dolfini, R.; Mauri, F.; Montanari, C.; Rappoldi, A.; Raselli, G.L.; Terrani, M.; Torre, P.; Vignoli, C.; Bettini, A.; Carpanese, C.; Centro, S.; Pepato, A.; Pietropaolo, F.; Ventura, S.; Bonesini, M.; Boschetti, B.; Calvi, M.; Curioni, A.; Cavalli, D.; Ferrari, A.; Ferrari, P.; Negri, P.; Paganoni, M.; Pullia, A.; Sala, P.; Ragazzi, S.; Redaelli, Nicola Giuseppe; Tabarelli De Fatis, T.; Terranova, F.; Tonazzo, A.; Casagrande, F.; Cennini, P.; Puccini, A.; Rubbia, A.; Rubbia, C.; Revol, J.P.; Cline, D.; Matthey, C.; Otwinowski, S.; Park, J.; Wang, H.; Woo, J.; Givoletti, J.; Lamarina, A.; Periale, R.; Picchi, P.; Mannocchi, G.; Periale, L.; Suzuki, S.; Sergiampietri, F.

1999-01-01

The 50 litre liquid Argon TPC is a detector built and successfully operated at CERN for R&D purposes within the ICARUS programme. In the year 1997 it has been exposed at the CERN neutrino beam for the entire SPS neutrino run period as proposed and approved at the SPSLC of January 1997. The detector, complemented with scintillators acting as veto, trigger counters and pre-shower counters, was installed in front of the NOMAD detector. The year 1997 was scheduled to be the last for the operation of the West Area Neutrino Facility. It was important to take this last opportunity for a parasitic exposure, which did not interfere with running experiments, of an already existing and operating liquid Argon TPC. As we had expected, the collected data brought important information for a better understanding of the performance of liquid Argon TPCs which should be useful for the entire ICARUS program. (9 refs).

The GAP-TPC

International Nuclear Information System (INIS)

Rossi, B.; Anastasio, A.; Boiano, A.; Cocco, A.G.; Meo, P. Di; Vanzanella, A.; Catalanotti, S.; Covone, G.; Longo, G.; Walker, S.; Fiorillo, G.; Wang, H.; Wang, Y.

2016-01-01

Several experiments have been conducted worldwide, with the goal of observing low-energy nuclear recoils induced by WIMPs scattering off target nuclei in ultra-sensitive, low-background detectors. In the last few decades noble liquid detectors designed to search for dark matter in the form of WIMPs have been extremely successful in improving their sensitivities and setting the best limits. One of the crucial problems to be faced for the development of large size (multi ton-scale) liquid argon experiments is the lack of reliable and low background cryogenic PMTs: their intrinsic radioactivity, cost, and borderline performance at 87 K rule them out as a possible candidate for photosensors. We propose a brand new concept of liquid argon-based detector for direct dark matter search: the Geiger-mode Avalanche Photodiode Time Projection Chamber (GAP-TPC) optimized in terms of residual radioactivity of the photosensors, energy and spatial resolution, light and charge collection efficiency

Structure of Voltage-gated Two-pore Channel TPC1 from Arabidopsis thaliana

Science.gov (United States)

Guo, Jiangtao; Zeng, Weizhong; Chen, Qingfeng; Lee, Changkeun; Chen, Liping; Yang, Yi; Cang, Chunlei; Ren, Dejian; Jiang, Youxing

2015-01-01

Two-pore channels (TPCs) contain two copies of a Shaker-like six-transmembrane (6-TM) domain in each subunit and are ubiquitously expressed in both animals and plants as organellar cation channels. Here, we present the first crystal structure of a vacuolar two-pore channel from Arabidopsis thaliana, AtTPC1, which functions as a homodimer. AtTPC1 activation requires both voltage and cytosolic Ca2+. Ca2+ binding to the cytosolic EF-hand domain triggers conformational changes coupled to the pair of pore-lining inner helices (IS6 helices) from the first 6-TM domains, whereas membrane potential only activates the second voltage-sensing domain (VSD2) whose conformational changes are coupled to the pair of inner helices (IIS6 helices) from the second 6-TM domains. Luminal Ca2+ or Ba2+ can modulate voltage activation by stabilizing VSD2 in the resting state and shifts voltage activation towards more positive potentials. Our Ba2+ bound AtTPC1 structure reveals a voltage sensor in the resting state, providing hitherto unseen structural insight into the general voltage-gating mechanism among voltage-gated channels. PMID:26689363

Search for H-dibaryon at J-PARC with a Large Acceptance TPC

Directory of Open Access Journals (Sweden)

Sako H.

2014-03-01

Full Text Available H-dibaryon has been predicted as a stable 6-quark color-singlet state. It has been searched for by many experiments but has never been discovered. Recent lattice QCD calculations predict H-dibaryon as a weakly bound or a resonant state close to the LL threshold. E224 and E522 experiments at KEK observed peaks in LL invariant mass spectra near the threshold in (K-, K+ reactions, which were statistically not significant. Therefore, we proposed a new experiment E42 at J-PARC. It will measure decay products of ΛΛ and Λπ-p in a (K-, K+ reaction. We design a large acceptance spectrometer based on a Time Projection Chamber (TPC immersed in a dipole magnetic field. The TPC surrounds a target to cover nearly 4π acceptance, and accepts K- beams up to 106 counts per second. To suppress drift field distortion at high beam rates, we adopt Gas Electron Multipliers (GEMs for electron amplification and a gating grid. We show an overview of the experiment, the design of the spectrometer, and the R&D status of the TPC prototype.

Future prospects of the TPC idea

Energy Technology Data Exchange (ETDEWEB)

Nygren, D R [California Univ., Berkeley (USA). Lawrence Berkeley Lab.

1981-04-01

General aspects affecting TPC size, readout plane characteristics and operation in the LEP environment are presented, with the general conclusion that modest improvements relative to PEP-4 can be realized in several areas. The problem of positive ion reduction is discussed according to two qualitatively new operating modes, asynchronous and synchronous gating. Either gating mode appears to offer a means to eliminate almost completely the ion return flux. Some speculative ideas involving 3-component gas mixtures, low-mass components and parallel plane geometry are presented as future possibilities.

Methods and results for calibration and track separation of a GEM based TPC using an UV-laser

International Nuclear Information System (INIS)

Ball, Markus

2008-12-01

, was substantially modified. This work can thus present a comprehensive study and results for the separation capability of nearby tracks, which was done in the ILC TPC community. (orig.)

Methods and results for calibration and track separation of a GEM based TPC using an UV-laser

Energy Technology Data Exchange (ETDEWEB)

Ball, Markus

2008-12-15

, was substantially modified. This work can thus present a comprehensive study and results for the separation capability of nearby tracks, which was done in the ILC TPC community. (orig.)

Gating of the two-pore cation channel AtTPC1 in the plant vacuole is based on a single voltage-sensing domain.

Science.gov (United States)

Jaślan, D; Mueller, T D; Becker, D; Schultz, J; Cuin, T A; Marten, I; Dreyer, I; Schönknecht, G; Hedrich, R

2016-09-01

The two-pore cation channel TPC1 operates as a dimeric channel in animal and plant endomembranes. Each subunit consists of two homologous Shaker-like halves, with 12 transmembrane domains in total (S1-S6, S7-S12). In plants, TPC1 channels reside in the vacuolar membrane, and upon voltage stimulation, give rise to the well-known slow-activating SV currents. Here, we combined bioinformatics, structure modelling, site-directed mutagenesis, and in planta patch clamp studies to elucidate the molecular mechanisms of voltage-dependent channel gating in TPC1 in its native plant background. Structure-function analysis of the Arabidopsis TPC1 channel in planta confirmed that helix S10 operates as the major voltage-sensing site, with Glu450 and Glu478 identified as possible ion-pair partners for voltage-sensing Arg537. The contribution of helix S4 to voltage sensing was found to be negligible. Several conserved negative residues on the luminal site contribute to calcium binding, stabilizing the closed channel. During evolution of plant TPC1s from two separate Shaker-like domains, the voltage-sensing function in the N-terminal Shaker-unit (S1-S4) vanished. © 2016 German Botanical Society and The Royal Botanical Society of the Netherlands.

Development of Time Projection Chambers with Micromegas for Rare Event Searches

CERN Document Server

Tomas, Alfredo; Villar, J A

The Rare Event Searches is a heterogeneous field from the point of view of their physical motivations: double betha neutrinoless decay experiments, direct detection of WIMPs as well as axions and other WISPs (candidates for the DM, but also motivated by other questions from Particle Physics). The field is rather defined by the requirements of these experiments, essentially a very sensitive detector with low background which is usually operated in underground laboratories. The availability of a rich description of the event registered by the detector is a powerful tool for the discrimination of the signal from the background. The topological description of the interaction that can be delivered by a gaseous TPC is a useful source of information about the event. The generic requirements for a gaseous TPC that is intended for rare event searches are very good imaging capabilities, high gain and efficiency, stability and reliability and radio-purity, which could imply working with particular gases, in absence of q...

AGS silicon gold collisions measured in the E-810 TPC [Time Projection Chamber

International Nuclear Information System (INIS)

Bonner, B.E.; Buchanan, J.A.; Chiou, C.N.; Clement, J.M.; Corcoran, M.D.; Kruk, J.W.; Miettinen, H.E.; Mutchler, G.S.; Nessi, M.; Nessi-Tedaldi, F.; Roberts, J.B.; Chan, C.S.; Kramer, M.A.; Etkin, A.; Foley, K.J.; Hackenburg, R.W.; Longacre, R.S.; Love, W.A.; Morris, T.W.; Platner, E.D.; Saulys, A.C.; Hallman, T.J.; Madansky, L.; Lindenbaum, S.J.

1990-01-01

The tracking detector of AGS Experiment 810 is a three-piece Time Projection Chamber (TPC) intended to measure all charged tracks in the forward hemisphere of the nucleon-nucleon center of mass system, i.e. forward of an angle of about 20 degrees in the lab. Each module of the TPC contains twelve rows of short anode wires which give 3-D space points on each track, but no dE/dx information useable for particle identification. The TPC was operated in a beam of silicon ions at the end of June 1989 and this talk reports the results of analysis of the data taken with a thin gold target in that run. We have gathered a similar amount of data from thin copper and silicon targets, the analysis of which is in a less advanced state. The results of our investigation of the neutral strange particle decays appear in a separate contribution by Al Saulys. This paper presents the current state of the analysis of the charged tracks from the silicon gold collisions. 1 ref., 15 figs

Lossy compression of TPC data and trajectory tracking efficiency for the ALICE experiment

CERN Document Server

Nicolaucig, A; Mattavelli, M

2003-01-01

In this paper a quasi-lossless algorithm for the on-line compression of the data generated by the Time Projection Chamber (TPC) detector of the ALICE experiment at CERN is described. The algorithm is based on a lossy source code modeling technique, i.e. it is based on a source model which is lossy if samples of the TPC signal are considered one by one; conversely, the source model is lossless or quasi-lossless if some physical quantities that are of main interest for the experiment are considered. These quantities are the area and the location of the center of mass of each TPC signal pulse, representing the pulse charge and the time localization of the pulse. So as to evaluate the consequences of the error introduced by the lossy compression process, the results of the trajectory tracking algorithms that process data off-line after the experiment are analyzed, in particular, versus their sensibility to the noise introduced by the compression. Two different versions of these off- line algorithms are described,...

First results from the CERES radial TPC

International Nuclear Information System (INIS)

Marin, A.; Agakichiev, G.; Appelshaeuser, H.; Baur, R.; Belaga, V.; Bell, R.; Braun-Munzinger, P.; Ceretto, F.; Cherlin, A.; Damjanovic, S.; Dietel, T.; Drees, A.; Ernst, P.; Esumi, S.I.; Filimonov, K.; Fraenkel, Z.; Gnaenski, A.; Garabatos, C.; Glaessel, P.; Hanzal, V.; Hausmann, M.; Hering, G.; Hrivnacova, I.; Holl, P.; Kushpil, V.; Lenkeit, B.; Messer, M.; Milov, A.; Miskowiec, D.; Panebrattsev, Y.; Petracek, V.; Pfeiffer, A.; Rak, J.; Ravinovich, I.; Razin, S.; Rehak, P.; Richter, M.; Saveljic, N.; Schaefer, E.; Schmitz, W.; Schukraft, J.; Seipp, W.; Sharma, A.; Shimansky, S.; Slivova, J.; Socol, E.; Specht, H.J.; Stachel, J.; Stiller, P.; Sumbera, M.; Tilsner, H.; Tserruya, I.; Voigt, C.; Voloshin, S.; Wessels, J.P.; Wienold, T.; Windelband, B.; Wurm, J.P.; Xie, W.; Yurevich, V.

1999-01-01

The CERES/NA45 experiment at the CERN SPS was upgraded in 1998 by the addition of a cylindrical Time Projection Chamber. The aim is to improve the mass resolution of e + e - pairs in the ρ/ω/phi region to Δm/m < 2%. A progress report is given on the TPC performance during the 1998 commissioning runs (laser rays, beam halo muons, and particles produced by proton/π and lead beams hitting Pb and Au targets)

Water data: bad TPC pads, 3.6 µs and 100 ns problems

CERN Document Server

Dydak, F; Nefedov, Y; Wotschack, J; Zhemchugov, A

2004-01-01

Out of the 3972 pads of the HARP TPC, about 9% are 'bad' and not useful for the correct reconstruction of clusters. Bad pads comprise dead pads, noisy pads, and pads with low or undefined amplification. Pads may be bad at one time, but not at another. This memo discusses the sources of information which were used to declare a pad 'bad', and gives the list of bad pads for the water data (runs 19146 to 19301). Also, the 3.6 µs and 100 ns problems of the TPC readout are discussed, including the corrective measures which have been taken.

Modular TPC's for relativistic heavy ion experiments

International Nuclear Information System (INIS)

Etkin, A.; Eiseman, S.E.; Foley, K.J.

1989-01-01

We have developed a TPC system for use in relativistic heavy ion experiments that permits the efficient reconstruction of high multiplicity events including events with decay vertices. It operates with the beam through the middle of the chamber giving good efficiency, two-track separation and spatial resolution. The three-dimensional points in this system allow the reconstruction of the complex events of interest. The use of specially developed hybrid electronics allows us to build a compact and cost-effective system. 11 figs

First results from the CERES radial TPC

CERN Document Server

AUTHOR|(CDS)2108583; Appelshäuser, H; Baur, R; Belaga, V; Bell, R; Braun-Munzinger, P; Ceretto, F; Cherlin, A; Damjanovic, S; Dietel, T; Drees, A; Ernst, P; Esumi, S I; Filimonov, K; Fraenkel, Zeev; Gnaenski, A; Garabatos, C; Glässel, P; Hanzal, V; Hausmann, M; Hering, G; Hrivnacova, I; Holl, P; Kushpil, V; Lenkeit, B C; Messer, M; Milov, A; Miskowiec, D; Panebratsev, Yu A; Petracek, V; Pfeiffer, A; Rak, J; Ravinovich, I; Razin, S; Rehak, P; Richter, M; Saveljic, N; Schäfer, E; Schmitz, W; Schükraft, Jürgen; Seipp, W; Sharma, A; Shimansky, S S; Slivova, J; Socol, E; Specht, H J; Stachel, J; Stiller, P; Sumbera, M; Tilsner, H; Tserruya, Itzhak; Voigt, C A; Voloshin, S A; Wessels, J P; Wienold, T; Windelband, B; Wurm, J P; Xie, W; Yurevich, V

1999-01-01

The CERES/NA45 experiment at the CERN SPS was upgraded in 1998 by the addition of a cylindrical Time Projection Chamber. The aim is to improve the mass resolution of e sup + e sup - pairs in the rho/omega/phi region to DELTA m/m < 2%. A progress report is given on the TPC performance during the 1998 commissioning runs (laser rays, beam halo muons, and particles produced by proton/pi and lead beams hitting Pb and Au targets).

First results from the CERES radial TPC

Energy Technology Data Exchange (ETDEWEB)

Marin, A.; Agakichiev, G.; Appelshaeuser, H.; Baur, R.; Belaga, V.; Bell, R.; Braun-Munzinger, P.; Ceretto, F.; Cherlin, A.; Damjanovic, S.; Dietel, T.; Drees, A.; Ernst, P.; Esumi, S.I.; Filimonov, K.; Fraenkel, Z.; Gnaenski, A.; Garabatos, C.; Glaessel, P.; Hanzal, V.; Hausmann, M.; Hering, G.; Hrivnacova, I.; Holl, P.; Kushpil, V.; Lenkeit, B.; Messer, M.; Milov, A.; Miskowiec, D.; Panebrattsev, Y.; Petracek, V.; Pfeiffer, A.; Rak, J.; Ravinovich, I.; Razin, S.; Rehak, P.; Richter, M.; Saveljic, N.; Schaefer, E.; Schmitz, W.; Schukraft, J.; Seipp, W.; Sharma, A.; Shimansky, S.; Slivova, J.; Socol, E.; Specht, H.J.; Stachel, J.; Stiller, P.; Sumbera, M.; Tilsner, H.; Tserruya, I.; Voigt, C.; Voloshin, S.; Wessels, J.P.; Wienold, T.; Windelband, B.; Wurm, J.P.; Xie, W.; Yurevich, V

1999-12-27

The CERES/NA45 experiment at the CERN SPS was upgraded in 1998 by the addition of a cylindrical Time Projection Chamber. The aim is to improve the mass resolution of e{sup +}e{sup -} pairs in the {rho}/{omega}/phi region to {delta}m/m < 2%. A progress report is given on the TPC performance during the 1998 commissioning runs (laser rays, beam halo muons, and particles produced by proton/{pi} and lead beams hitting Pb and Au targets)

R and D on a Fast LXe TPC with real-time event reconstruction

Energy Technology Data Exchange (ETDEWEB)

Dussoni, S., E-mail: simeone.dussoni@pi.infn.it [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Baldini, A. [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Galli, L. [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Paul Scherrer Institute PSI, CH-5232 Villigen (Switzerland); Cerri, C.; Grassi, M. [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Papa, A. [Paul Scherrer Institute PSI, CH-5232 Villigen (Switzerland); Signorelli, G. [INFN Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy)

2013-12-21

The FOXFIRE project (Feasibility Of a Xenon detector with Front-end for Ionization Real-time Extraction) aims at the realization of a Liquid Xenon TPC optimized for high rate particle physics experiments, in particular in the field of rare event searches, with particles in the 10–100 MeV energy range. Liquid Xenon has several attractive properties to be exploited resulting in superior time and energy resolution, by using the scintillation light readout with suitable photo-detectors. A novel approach with a complementary TPC readout scheme can improve the space resolution to a level of a few hundred microns. We are studying both the feasibility of a light readout with higher granularity by means of Silicon PhotoMultipliers optimized for the Xenon emission spectrum as well as on an innovative micro-fabricated device capable of charge multiplication in liquid phase. The detector will be equipped with a readout electronics capable of online reconstruction of events, allowing the detector to sustain a high rate of interactions.

ARIADNE, a Photographic LAr TPC at the CERN Neutrino Platform

CERN Document Server

Mavrokoridis, K; Nessi, M; Roberts, A; Smith, N A; Touramanis, C; CERN. Geneva. SPS and PS Experiments Committee; SPSC

2016-01-01

This letter of intent describes a novel and innovative two-phase LAr TPC with photographic capabilities as an attractive alternative readout method to the currently accepted segmented THGEMs which will require many thousands of charge readout channels for kton-scale two-phase TPCs. These colossal LAr TPCs will be used for the future long-baseline-neutrino-oscillation experiments. Optical readout also presents many other clear advantages over current readout techniques such as ease of scalability, upgrade, installation and maintenance, and cost effectiveness. This technology has already been demonstrated at the Liverpool LAr facility with the photographic capturing of cosmic muon tracks and single gammas using a 40-litre prototype. We have now secured ERC funding to develop this further with the ARIADNE programme. ARIADNE will be a 1-ton two-phase LAr TPC utilizing THGEM and EMCCD camera readouts in order to photograph interactions, allowing for track reconstruction and particle identification. We are request...

A low-background Micromegas detector for axion searches

CERN Document Server

Andriamonje, Samuel A; Dafni, T; Delagnes, E; Fanourakis, G K; Ferrer-Ribas, Esther; Geralis, T; Giomataris, Ioanis; Kousouris, K; Papaevangelou, T; Zachariadou, K

2004-01-01

A micropattern low-background detector based on the Micromegas technology has been designed and constructed for the CERN Axion Search experiment CAST. The detector is made of low natural radioactivity materials and has a two-dimensional readout with X-Y strip structure. It is operated with an Argon/Isobutane (95%/5%) mixture and is controlled by a VME data acquisition system. The detector is sensitive to photons in the energy range of 1-10 keV, it has a linear response, excellent stability and a very good energy resolution (14% FWHM at 5.9 keV). This device has been in stable operation since October 2002, taking data during the running periods of the CAST experiment. At the end of summer 2003, the detector was upgraded with a flash ADC readout of the grid signal to further improve its background rejection capability. The currently achieved background rate under normal operation is about 2.0 multiplied by 10 **-**5 events/keV/cm**2/s with better than 85% software efficiency.

Development and prospects of the new gaseous detector 'Micromegas'

International Nuclear Information System (INIS)

Giomataris, Y.

1998-01-01

We report results obtained with the novel gaseous Micromegas detector (MICRO MEsh GAseous Structure), which is under development at Saclay. A simple theory to explain the advantage of the small amplification gap (50-100 μm) is developed. A set of large detectors was exposed during several months in high-intensity particle beams. Full efficiency and a large plateau has been obtained with a 3 mm conversion gap. With a conversion gap as small as 1 mm the efficiency reaches 96 %. A spatial resolution better then 60 μm has been observed with anode strips of 317 μm pitch. Simulations show that with a pitch of 100 μm and the appropriate gas an accuracy of 10 μm and a time resolution of 1 νs is within reach. This development leads to a new generation of cheap position sensitive detectors which would permit high precision tracking or vertexing close to the interaction region, in very high-rate environments. (author)

Status of the R&D activities for the upgrade of the ALICE TPC

Science.gov (United States)

Deisting, Alexander

2018-02-01

After the Long Shutdown 2 (LS2) the LHC will provide lead-lead collisions at interaction rates as high as 50 kHz. In order to cope with such conditions the ALICE Time Projection Chamber (TPC) needs to be upgraded. After the upgrade the TPC will run in a continuous mode, without any degradation of the momentum and dE/dx resolution compared to the performance of the present TPC. Since readout by multi-wire proportional chambers is no longer feasible with these requirements, new technologies have to be employed. In the new readout chambers the electron amplification is provided by a stack of four Gas ElectronMultiplier (GEM) foils. Here foils with a standard hole pitch of 140 μm as well as large pitch foils (280 μm) are used. Their high voltage settings and orientation have been optimised to provide an energy resolution of σE/E ≤ 12% at the photopeak of 55Fe. At the same settings the Ion BackFlow into the drift volume is less than 1% of the effective number of ions produced during gas amplification and the primary ionisations. This is necessary to prevent the accumulation of space charge, which eventually will distort the field in the drift volume. To ensure stable operation at the high loads during LHC run 3 the chambers have to be robust against discharges, too. With the selected configuration in a quadruple GEMstack the discharge probability is kept at the level of 10-12 discharges per incoming hadron. An overview of the ALICE TPC upgrade activities will be given in these proceedings and the optimised settings foreseen for the GEM stacks of the future readout chambers are introduced. Furthermore the outcome of two beam time campaigns at SPS and PS (at CERN) in the end of 2014 is shown. At this campaigns the stability against discharges and the dE/dx performance of a full size readout chamber prototype was tested. In addition it is reported on charging-up studies of 4GEM stacks and on tests of electromagnetic sagging of large GEM foils.

Simulation of double beta decay in the 'SeXe' TPC

Energy Technology Data Exchange (ETDEWEB)

Mauger, F [LPC Caen and University of Caen, ENSICAEN, 6 Bd Marechal Juin, 14050 CAEN CEDEX 4 (France)

2007-04-15

In 2004, the NEMO collaboration has started some preliminary studies for a next-generation double beta decay experiment: SuperNEMO. The possibility to use a large gaseous TPC has been investigated using simulation and extrapolation of former experiments. In this talk, I report on the reasons why such techniques have not been selected in 2004 and led the NEMO collaboration to reuse the techniques implemented within the NEMO3 detector.

The 40x40cm2 gaseous microstrip detector Micromegas for the high-luminosity COMPASS experiment at CERN

International Nuclear Information System (INIS)

Bernet, C.; Abbon, P.; Ball, J.; Bedfer, Y.; Delagnes, E.; Giganon, A.; Kunne, F.; Le Goff, J.-M.; Magnon, A.; Marchand, C.; Neyret, D.; Panebianco, S.; Pereira, H.; Platchkov, S.; Procureur, S.; Rebourgeard, P.; Tarte, G.; Thers, D.

2005-01-01

The measurements in the COMPASS experiment at CERN require high-resolution tracking detectors, with low radiation length and high-rate capability. For this purpose we have developed and optimized a gaseous microstrip detector 'Micromegas'. Twelve planes with 1024 strips each, assembled in 3 stations of 4 views XYUV, are now being operated with success in the COMPASS environment. We describe here the performances and results obtained

Meson and baryon correlation studies using the PEP-TPC/2γ Facility

International Nuclear Information System (INIS)

Ronan, M.T.

1991-03-01

Results on vector meson, and strange and charmed-baryon production are presented for data taken during the period 1982--1986 using the TPC/2γ detector at PEP. Vector mesons (ρ 0 , K * and φ) with 0, 1 and 2 strange quarks are used to obtain redundant measures of strange-quark suppression and of the vector to pseudoscalar ratio in hadronization. Measurements of the production rates of Λ, Ξ - , Ω and Ξ *0 hyperons and for the Λ c and of rapidity correlations between Λ bar Λ pairs provide sensitive tests of baryon production in fragmentation models. In addition, two- and three-particle correlations between like sign pions provide further evidence for the Bose-Einstein effect in e + e - interactions including the relativistic motion of particle sources. 9 refs., 7 figs

Measuring Cross-Section and Estimating Uncertainties with the fissionTPC

Energy Technology Data Exchange (ETDEWEB)

Bowden, N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Manning, B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Sangiorgio, S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Seilhan, B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2015-01-30

The purpose of this document is to outline the prescription for measuring fission cross-sections with the NIFFTE fissionTPC and estimating the associated uncertainties. As such it will serve as a work planning guide for NIFFTE collaboration members and facilitate clear communication of the procedures used to the broader community.

On distortions of TPC coordinates: inhomogeneities of electric and magnetic field

CERN Document Server

Dydak, F

2003-01-01

After a general discussion of electron drift in a gas volume with electric and magnetic fields, distortions in the r and r phi coordinates arising from inhomogeneities of the electric and magnetic fields in the HARP TPC are calculated. Inhomogeneities of the electric field arise from i) positive ions released by cosmic rays, ii) positive ions released by interaction secondaries, iii) positive ions released by beam muons, iv) positive ions released from beam particles downstream of the inner field cage, and v) a high voltage misalignment between the outer and inner field cages. Also, distortions arising from the inhomogeneity of the magnetic field are calculated. These effects resolve the controversy on unphysical numbers of 'wrong-charge' TPC tracks. The bad news are that effects are too big to be neglected. The good news are that, with enough sweat and tears, they can be adequately corrected.

Performance of an optical readout GEM-based TPC

International Nuclear Information System (INIS)

Margato, L.M.S.; Fraga, F.A.F.; Fetal, S.T.G.; Fraga, M.M.F.R.; Balau, E.F.S.; Blanco, A.; Marques, R. Ferreira; Policarpo, A.J.P.L

2004-01-01

We report on the operation of a GEM-based small TPC using an optical readout. The detector was operated with a mixture of Ar+CF 4 using 5.48 MeV alpha particles obtained from a 241 Am source and the GEM scintillation was concurrently read by a CCD camera and a photomultiplier. Precision collimators were used to define the track orientation. Qualitative results on the accuracy of the track angle, length and charge deposition measurements are presented

Characterization of UV-enhanced SiPMs for Imaging in High Pressure Xenon Electroluminescent TPC

International Nuclear Information System (INIS)

Yahlali, Nadia; Lorca, David; Fernandes, L.M.P.

2013-06-01

The possibility of recording charged particle tracks in an electro-luminescent xenon gas TPC is investigated using a SiPM-based tracking system, operated in the demonstrator prototype of the NEXT-100 ββ decay experiment. The tracks of the ββ0ν events from the decay of the 136 Xe isotope have a distinctive topology, which allows their discrimination against single-electron events from the natural radioactivity that populates the region of interest of the neutrinoless decay in the ββ energy spectrum. Combined to the near-intrinsic energy resolution of the gaseous detector, this tracking capability provides a powerful background rejection tool for the search of the neutrinoless ββ decay aimed by the experiment. The NEXT-100 detector concepts and sensitivity and the first results of its demonstrator prototype are presented. The characterization studies relevant for the operation of UV-enhanced SiPMs used for imaging in an electro-luminescent TPC are reviewed. (authors)

Gossip: Gaseous pixels

Science.gov (United States)

Koffeman, E. N.

2007-12-01

Several years ago a revolutionary miniature TPC was developed using a pixel chip with a Micromegas foil spanned over it. To overcome the mechanical stability problems and improve the positioning accuracy while spanning a foil on top of a small readout chip a process has been developed in which a Micromegas-like grid is applied on a CMOS wafer in a post-processing step. This aluminum grid is supported on insulating pillars that are created by etching after the grid has been made. The energy resolution (measured on the absorption of the X-rays from a 55Fe source) was remarkably good. Several geometries have since been tested and we now believe that a Gas On Slimmed Silicon Pixel chip' (Gossip) may be realized. The drift region of such a gaseous pixel detector would be reduced to a millimeter. Such a detector is potentially very radiation hard (SLHC vertexing) but aging and sparking must be eliminated.

Gossip: Gaseous pixels

Energy Technology Data Exchange (ETDEWEB)

Koffeman, E.N. [Nikhef, Kruislaan 409, 1098 SJ Amsterdam (Netherlands)], E-mail: d77@nikhef.nl

2007-12-01

Several years ago a revolutionary miniature TPC was developed using a pixel chip with a Micromegas foil spanned over it. To overcome the mechanical stability problems and improve the positioning accuracy while spanning a foil on top of a small readout chip a process has been developed in which a Micromegas-like grid is applied on a CMOS wafer in a post-processing step. This aluminum grid is supported on insulating pillars that are created by etching after the grid has been made. The energy resolution (measured on the absorption of the X-rays from a {sup 55}Fe source) was remarkably good. Several geometries have since been tested and we now believe that a Gas On Slimmed Silicon Pixel chip' (Gossip) may be realized. The drift region of such a gaseous pixel detector would be reduced to a millimeter. Such a detector is potentially very radiation hard (SLHC vertexing) but aging and sparking must be eliminated.

Gossip: Gaseous pixels

International Nuclear Information System (INIS)

Koffeman, E.N.

2007-01-01

Several years ago a revolutionary miniature TPC was developed using a pixel chip with a Micromegas foil spanned over it. To overcome the mechanical stability problems and improve the positioning accuracy while spanning a foil on top of a small readout chip a process has been developed in which a Micromegas-like grid is applied on a CMOS wafer in a post-processing step. This aluminum grid is supported on insulating pillars that are created by etching after the grid has been made. The energy resolution (measured on the absorption of the X-rays from a 55 Fe source) was remarkably good. Several geometries have since been tested and we now believe that a Gas On Slimmed Silicon Pixel chip' (Gossip) may be realized. The drift region of such a gaseous pixel detector would be reduced to a millimeter. Such a detector is potentially very radiation hard (SLHC vertexing) but aging and sparking must be eliminated

TPC2 is a novel NAADP-sensitive Ca2+ release channel, operating as a dual sensor of luminal pH and Ca2+.

Science.gov (United States)

Pitt, Samantha J; Funnell, Tim M; Sitsapesan, Mano; Venturi, Elisa; Rietdorf, Katja; Ruas, Margarida; Ganesan, A; Gosain, Rajendra; Churchill, Grant C; Zhu, Michael X; Parrington, John; Galione, Antony; Sitsapesan, Rebecca

2010-11-05

Nicotinic acid adenine dinucleotide phosphate (NAADP) is a molecule capable of initiating the release of intracellular Ca(2+) required for many essential cellular processes. Recent evidence links two-pore channels (TPCs) with NAADP-induced release of Ca(2+) from lysosome-like acidic organelles; however, there has been no direct demonstration that TPCs can act as NAADP-sensitive Ca(2+) release channels. Controversial evidence also proposes ryanodine receptors as the primary target of NAADP. We show that TPC2, the major lysosomal targeted isoform, is a cation channel with selectivity for Ca(2+) that will enable it to act as a Ca(2+) release channel in the cellular environment. NAADP opens TPC2 channels in a concentration-dependent manner, binding to high affinity activation and low affinity inhibition sites. At the core of this process is the luminal environment of the channel. The sensitivity of TPC2 to NAADP is steeply dependent on the luminal [Ca(2+)] allowing extremely low levels of NAADP to open the channel. In parallel, luminal pH controls NAADP affinity for TPC2 by switching from reversible activation of TPC2 at low pH to irreversible activation at neutral pH. Further evidence earmarking TPCs as the likely pathway for NAADP-induced intracellular Ca(2+) release is obtained from the use of Ned-19, the selective blocker of cellular NAADP-induced Ca(2+) release. Ned-19 antagonizes NAADP-activation of TPC2 in a non-competitive manner at 1 μM but potentiates NAADP activation at nanomolar concentrations. This single-channel study provides a long awaited molecular basis for the peculiar mechanistic features of NAADP signaling and a framework for understanding how NAADP can mediate key physiological events.

arXiv Status of the R&D activities for the upgrade of the ALICE TPC

CERN Document Server

Deisting, Alexander

2018-01-01

In order to cope with the high interaction rates provided by the LHC after the long shut-down 2, the ALICE TPC needs to be upgraded. After the upgrade the TPC will run in a continuous mode, without any degradation of the momentum and $\\textrm{d}E/\\textrm{d}x$ resolution compared to the performance of the present TPC. Since readout by MWPCs is no longer feasible with these requirements, new technologies have to be employed. In the new readout the electron amplification is provided by a stack of four GEM foils. Here foils with a standard hole pitch of 140um as well as large pitch foils (280um) are used. Their high voltage settings and orientation have been optimised to provide an energy resolution of $\\sigma_{{E}}/{E}\\leq12\\%$ at the photopeak of $^{55}\\textrm{Fe}$. At the same settings the Ion BackFlow into the drift volume is less than 1% of the effective number of ions produced during gas amplification and the primary ionisations. This is necessary to prevent the accumulation of space charge, which eventuall...

The ALICE TPC, a high resolution device for ultra-high particle multiplicities. Past, present and future

Energy Technology Data Exchange (ETDEWEB)

Ivanov, Marian [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH (Germany); Collaboration: ALICE-Collaboration

2015-07-01

The Time Projection Chamber (TPC) of the ALICE apparatus is a large 3-dimensional tracking and particle identification device for ultra-high multiplicity collision events. It has been operated successfully at the Large Hadron Collider (LHC) at CERN, recording data from pp, p-Pb, and Pb-Pb collisions. Presently, LHC is in its first long shutdown (LS1), the next round of data taking will start in summer 2015 at or close to the LHC design energy and luminosity. During the second long shutdown (LS2), LHC will undergo a further increase in the Pb-Pb luminosity together with a major upgrade of ALICE. After the upgrade, the ALICE TPC will operate with Pb-Pb collisions at an interaction rate of 50 kHz. We present the performance in operation, calibration and reconstruction with the ALICE TPC together with ongoing work and plans for the near future and the coming 10 years.

Development of the GEM-TPC X-ray Polarimeter with the Scalable Readout System

Directory of Open Access Journals (Sweden)

Kitaguchi Takao

2018-01-01

Full Text Available We have developed a gaseous Time Projection Chamber (TPC containing a single-layered foil of a gas electron multiplier (GEM to open up a new window on cosmic X-ray polarimetry in the 2–10 keV band. The micro-pattern TPC polarimeter in combination with the Scalable Readout System produced by the RD51 collaboration has been built as an engineering model to optimize detector parameters and improve polarimeter sensitivity. The polarimeter was characterized with unpolarized X-rays from an X-ray generator in a laboratory and polarized X-rays on the BL32B2 beamline at the SPring-8 synchrotron radiation facility. Preliminary results show that the polarimeter has a comparable modulation factor to a prototype of the flight one.

Progress on a spherical TPC for low energy neutrino detection

International Nuclear Information System (INIS)

Aune, S; Colas, P; Deschamps, H; Dolbeau, J; Fanourakis, G; Ribas, E Ferrer; Enqvist, T; Geralis, T; Giomataris, Y; Gorodetzky, P; Gounaris, G J; Gros, M; Irastorza, I G; Kousouris, K; Lepeltier, V; Morales, J; Patzak, T; Paschos, E A; Salin, P; Savvidis, I; Vergados, J D

2006-01-01

The new concept of the spherical TPC aims at relatively large target masses with low threshold and background, keeping an extremely simple and robust operation. Such a device would open the way to detect the neutrino-nucleus interaction, which, although a standard process, remains undetected due to the low energy of the neutrino-induced nuclear recoils. The progress in the development of the first 1 m 3 prototype at Saclay is presented. Other physics goals of such a device could include supernova detection, low energy neutrino oscillations and study of non-standard properties of the neutrino, among others

Readout and trigger electronics for the TPC vertex chamber

International Nuclear Information System (INIS)

Ronan, M.T.; Jared, R.C.; McGathen, T.K.; Eisner, A.M.; Broeder, W.J.; Godfrey, G.L.

1987-10-01

The introduction of the vertex chamber required the addition of new front-end electronics and a new 1024-channel, high-accuracy TDC system. The preamplifier/discriminator should be capable of triggering on the first electrons and the time digitzer should preserve the measurement resolution. For the TDC's, in order to maintain compatibility with the existing TPC readout system, an upgrade of a previous inner drift chamber digitizer system has been chosen. Tests of the accuracy and stability of the original design indicated that the new design specifications would be met. The TPC detector requires a fast pretrigger to turn on its gating grid within 500 ns of the e/sup +/e/sup -/ beam crossing time, to minimize the loss of ionization information. A pretrigger based on the Straw Chamber signals, operating at a rate of about 2 K/sec, will be used for charged particle final states. In addition, in order to reject low mass Two-Photon events at the final trigger level, an accurate transverse momentum cutoff will be made by the Straw Chamber trigger logic. In this paper, we describe the readout and trigger electronics systems which have been built to satisfy the above requirements. 5 refs., 8 figs

Status of the R&D activities for the upgrade of the ALICE TPC

Directory of Open Access Journals (Sweden)

Deisting Alexander

2018-01-01

After the upgrade the TPC will run in a continuous mode, without any degradation of the momentum and dE/dx resolution compared to the performance of the present TPC. Since readout by multi-wire proportional chambers is no longer feasible with these requirements, new technologies have to be employed. In the new readout chambers the electron amplification is provided by a stack of four Gas ElectronMultiplier (GEM foils. Here foils with a standard hole pitch of 140 μm as well as large pitch foils (280 μm are used. Their high voltage settings and orientation have been optimised to provide an energy resolution of σE/E ≤ 12% at the photopeak of 55Fe. At the same settings the Ion BackFlow into the drift volume is less than 1% of the effective number of ions produced during gas amplification and the primary ionisations. This is necessary to prevent the accumulation of space charge, which eventually will distort the field in the drift volume. To ensure stable operation at the high loads during LHC run 3 the chambers have to be robust against discharges, too. With the selected configuration in a quadruple GEMstack the discharge probability is kept at the level of 10-12 discharges per incoming hadron. An overview of the ALICE TPC upgrade activities will be given in these proceedings and the optimised settings foreseen for the GEM stacks of the future readout chambers are introduced. Furthermore the outcome of two beam time campaigns at SPS and PS (at CERN in the end of 2014 is shown. At this campaigns the stability against discharges and the dE/dx performance of a full size readout chamber prototype was tested. In addition it is reported on charging-up studies of 4GEM stacks and on tests of electromagnetic sagging of large GEM foils.

Micromegas R&D for ATLAS MUON PHASE II Upgrade

CERN Document Server

Farina, Edoardo Maria; The ATLAS collaboration

2017-01-01

In the framework of the ATLAS Phase II Upgrade, a proposal to extend the detector acceptance of the muon system to high η has been put forward (namely up to | η| ~ 4). Extension of the muon coverage has been demonstrated to enhance physics performance. The proposed location for the new detector is in between the end-cap calorimeter cryostat and the JD shielding; in this region there is no magnetic field applied, the aim of the new detector is therefore to only tag muons without performing any momentum measurement. The new η tagger should cope with extremely high particle rate, that has been calculated, by means of simulations, to be 9 MHz at R = 25 cm and 0.4 MHz at R = 60 cm for μ = 200, where μ stands for the number of pp collisions per bunch crossing. The required spatial resolution at the inner edge of the detector has been estimated in few hundreds micrometres. One of the most promising candidate technology for the new detector is the MicroMegaS one, which has already been adopted for the NSW upgrad...

Modelling the behaviour of microbulk Micromegas in Xenon/trimethylamine gas

CERN Document Server

Ruiz-Choliz, E; Diago, A; Castel, J; Dafni, T; Herrera, D C; Iguaz, F J; Irastorza, I G; Luzon, G; Mirallas, H; Sahin,  O; Veenhof, R

2015-01-01

We model the response of a state of the art micro-hole single-stage charge amplication device (`microbulk' Micromegas) in a gaseous atmosphere consisting of Xenon/trimethylamine at various concentrations and pressures. The amplifying structure, made with photo-lithographic techniques similar to those followed in the fabrication of gas electron multipliers (GEMs), consisted of a 100 um-side equilateral-triangle pattern with 50 um-diameter holes placed at its vertexes. Once the primary electrons are guided into the holes by virtue of an optimized field configuration, avalanches develop along the 50 um-height channels etched out of the original doubly copper-clad polyimide foil. In order to properly account for the strong field gradients at the holes' entrance as well as for the fluctuations of the avalanche process (that ultimately determine the achievable energy resolution), we abandoned the hydrodynamic framework, resorting to a purely microscopic description of the electron trajectories as obtained from elem...

The liquid argon TPC for the ICARUS experiment

CERN Document Server

Arneodo, F

1997-01-01

The ICARUS project aims at the realisation of a large liquid argon TPC to be run at the Underground Laboratories of Gran Sasso in Italy. An intense R&D; activity has put on firm grounds this new detector technology and experimentally confirmed its feasibility on a few ton scale. Based on these solid achievements, the collaboration is now confident of being able to build and safely operate a multi-kton detector. The reseach program of the experiment involves the systematic study of a wide spectrum of physical phenomena covering many orders of magnitude in the energy deposited in the detector: from the few MeV of solar neutrino interactions, to the about one GeV of the proton decay and atmospheric neutrinos, up to the higher energies of neutrinos from accelerators.

Planarity certification of ATLAS Micromegas detector panels

Energy Technology Data Exchange (ETDEWEB)

Mueller, Ralph; Biebel, Otmar; Bortfeldt, Jonathan; Flierl, Bernhard; Hertenberger, Ralf; Loesel, Philipp; Herrmann, Maximilian [LMU Muenchen (Germany); Zibell, Andre [JMU Wuerzburg (Germany)

2016-07-01

During the second long LHC shutdown, 2019/20, the precision tracking detectors of the ATLAS muon spectrometer in the inner end caps will be replaced using Micromegas, a planar gas-detector technology. Modules of 2 m{sup 2} area are built in quadruplets from five precisely planar sandwich panels that define the anodes and the cathodes of the four active detector planes. A panel is composed of three consecutive layers FR4 - aluminum honeycomb - FR4. Single plane spatial particle resolution below 100 μm is achievable when the deviations from planarity of the strip-anodes do not exceed 80 μm RMS over the whole active area and the parallelism of the readout strips is within 30 μm. In order to measure the dimensional accuracy of each panel, laser distance sensors combined with a coordinate measurement system have been investigated. The sensor requirements to measure the planarity of the panels are a resolution of 0.3 μm and a beam spot diameter of ∼20 μm, well below 100 μ m the size of the smallest structures. We report on achieved planarities of the panels and the performance of the laser sensor system. A panel with an RMS better than 30 μm was build and the evolution of its planarity due to humidity and temperature effects is shown.

Results on search for a QGP with a TPC magnetic spectrometer at AGS and plans for an ∼4π TPC magnetic spectrometer at RHIC

International Nuclear Information System (INIS)

Lindenbaum, S.J.

1991-01-01

In the first part of this paper a search for a Quark-Gluon Plasma (QGP) with a TPC Magnetic Spectrometer at AGS by the BNL/CCNY/Johns Hopkins/Rice (E-810) Collaboration is discussed. At AGS energies the expected increase in baryon density is near maximum. If a QGP is formed even rarely this approach provides a sensitive method for its detection. We have found some interesting phenomena including strangeness enhancement, multi-Λ and K s 0 events and an increased slope for π - (corresponding to a reduced temperature) in the usual temperature plot for p perpendicular < 0.2 GeV/c. We plan to increase the statistics with the 14.5 GeV/c x A Si ions on targets from light to heavy and then to continue the program with incident Au ions. In Part 2 we discuss the BNL/CCNY/Notre Dame/Rice proposal for an ∼ 4π TPC Magnetic Spectrometer for RHIC which we believe will be a sensitive probe for hadronic QGP signals, and also capable of observing departures from QCD should they occur. 8 refs., 12 figs

Design of the ATLAS New Small Wheel Gas Distribution System for the Micromegas Detector Modules

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00084094; The ATLAS collaboration; Alexopoulos, Theodoros; Maltezos, Stavros; Vlachos, Sotirios; Karentzos, Efstathios; Koulouris, Aimilianos; Moschovakos, Paris; Koutelieris, Georgios

2016-01-01

In this work we present and describe the methodology, the particular calculations and simulations accordingly to achieve the appropriate gas flow rates ensuring a uniform gas distribution among the same type of NSW Micromegas modules. The majority of the components used are in large multiplicity so space saving criteria is taking into account and simplicity on the performance with respect to the total cost as well. An appropriate simulation program has been developed for studying the overall gas system determining the gauge pressure, flow rate in the crucial points and branches, respectively. Moreover, an overall prototype configuration, implemented at the NTUA laboratory and based on the Lock-in Amplifier technique to be used in conjunction with the gas leak test via the FRL method is presented. The obtained performances, by means of sensitivity and S/N ratio improvement, are also discussed.

The first Module0 MicroMegas Chamber for the New Small Wheel Upgrade of the ATLAS Muon Spectrometer: Features and Performances

CERN Document Server

Palazzo, Serena; The ATLAS collaboration

2017-01-01

After the second long shutdown (LS2) in 2019-2020, the LHC luminosity will be increased up to 2-3$\\cdot$10$^{34}$ cm$^{-2}$ s$^{-1}$ in Phase$-$1 and eventually to 7$\\cdot$10$^{34}$ cm$^{-2}$ s$^{-1}$ in the High Luminosity LHC era. While high luminosity will provide more data, it is essential that the ATLAS detectors are still able to operate in the higher background environment maintaining their performances as good as that at lower luminosities. To obtain this, some of the detectors that are located nearest to the beam pipe have to be replaced. For the upgrade of the ATLAS Muon Spectrometer the present Small Wheel equipped with CSC, MDT and TGC chambers will be replaced the New Small Wheel. This will contain two new detector types: the MicroMegas (MM) and the small-strip TGC (sTGC). The first Module-0 of Micromegas quadruplet has been built by a consortium of several INFN groups in Italy and tested with high energy particles at the H8 SPS Test Beam experimental area at CERN in June 2016. The construction o...

Ion Feedback Suppression Using Inclined MCP Holes in a Single-MCP+Micromegas+Pads Detector

International Nuclear Information System (INIS)

Va'vra, J.; Sumiyoshi, T.

2005-01-01

We show that the ion backflow to photocathode can be completely suppressed if one uses inclined MCP holes in a presence of magnetic field. The inclined hole angles are chosen to be aligned with the Lorentz electron angle allowing the electron transmission and amplification, while positive ions, traveling along a different angle, are caught on the MCP hole walls. The detector under investigation is a new gaseous detector structure based on a tandem of two parts, a single MCP (Microchannel) plate, a Micromegas with pad readout. We are aiming to develop a gaseous photon detector with the Bialkali photocathode, however, one could use some ideas in the paper for other types of detectors

Ion feedback suppression using inclined MCP holes in a 'single-MCP+micromegas+pads' detector

International Nuclear Information System (INIS)

Va'vra, J.; Sumiyoshi, T.

2005-01-01

We show that the ion backflow to photocathode can be completely suppressed if one uses inclined MCP holes in the presence of a magnetic field. The inclined hole angles are chosen to be aligned with the Lorentz electron angle allowing the electron transmission and amplification, while positive ions, traveling along a different angle, are caught on the MCP hole walls. The detector under investigation is a new gaseous detector structure based on a tandem of two parts, a single MCP (microchannel plate), a micromegas with pad readout. We are aiming to develop a gaseous photon detector with the Bialkali photocathode, however, one could use some ideas in the paper for other types of detectors

Fast algorithm of track reconstruction for the Delphy TPC

International Nuclear Information System (INIS)

Maillard, J.

1984-01-01

We describe a simple geometrical method (polar inversion) to reconstruct tracks. When the magnetic field is constant in magnitude and direction. This method uses geometrical properties of the trajectories. In the case of the DELPHI apparatus, the track reconstruction is done using TPC informations. After explaining the algorithm, we give results on ''GEANT'' simulated events using the ''Lund'' generator. Today we get a computer time of the order of 1.2 milliseconds on a CDC 7600 and an efficiency of 98% [fr

Online Calibration of the TPC Drift Time in the ALICE High Level Trigger

Science.gov (United States)

Rohr, David; Krzewicki, Mikolaj; Zampolli, Chiara; Wiechula, Jens; Gorbunov, Sergey; Chauvin, Alex; Vorobyev, Ivan; Weber, Steffen; Schweda, Kai; Lindenstruth, Volker

2017-06-01

A Large Ion Collider Experiment (ALICE) is one of the four major experiments at the Large Hadron Collider (LHC) at CERN. The high level trigger (HLT) is a compute cluster, which reconstructs collisions as recorded by the ALICE detector in real-time. It employs a custom online data-transport framework to distribute data and workload among the compute nodes. ALICE employs subdetectors that are sensitive to environmental conditions such as pressure and temperature, e.g., the time projection chamber (TPC). A precise reconstruction of particle trajectories requires calibration of these detectors. Performing calibration in real time in the HLT improves the online reconstructions and renders certain offline calibration steps obsolete speeding up offline physics analysis. For LHC Run 3, starting in 2020 when data reduction will rely on reconstructed data, online calibration becomes a necessity. Reconstructed particle trajectories build the basis for the calibration making a fast online-tracking mandatory. The main detectors used for this purpose are the TPC and Inner Tracking System. Reconstructing the trajectories in the TPC is the most compute-intense step. We present several improvements to the ALICE HLT developed to facilitate online calibration. The main new development for online calibration is a wrapper that can run ALICE offline analysis and calibration tasks inside the HLT. In addition, we have added asynchronous processing capabilities to support long-running calibration tasks in the HLT framework, which runs event-synchronously otherwise. In order to improve the resiliency, an isolated process performs the asynchronous operations such that even a fatal error does not disturb data taking. We have complemented the original loop-free HLT chain with ZeroMQ data-transfer components. The ZeroMQ components facilitate a feedback loop that inserts the calibration result created at the end of the chain back into tracking components at the beginning of the chain, after a

The study of hadronic matter at the highest density; the search for the deconfined quark-gluon phase using 2 TeV anti p-p collisions; and the exclusive study of nuclear fragmentation using the Lawrence Berkeley Laboratory EOS-TPC

International Nuclear Information System (INIS)

Scharenberg, R.P.; Hirsch, A.S.

1990-01-01

This report discusses the: Fermilab experiment 735, a search for the quark-gluon plasma; an exclusive study of nuclear fragmentation using the EOS-TPC; and a study of the central rapidity region at the relativistic heavy ion collider

Modelling the behaviour of microbulk Micromegas in xenon/trimethylamine gas

Energy Technology Data Exchange (ETDEWEB)

Ruiz-Choliz, E. [Laboratorio de Física Nuclear y Astropartículas, Universidad de Zaragoza, Zaragoza (Spain); Laboratorio Subterráneo de Canfranc, Canfranc (Spain); González-Díaz, D., E-mail: diegogon@cern.ch [Laboratorio de Física Nuclear y Astropartículas, Universidad de Zaragoza, Zaragoza (Spain); Laboratorio Subterráneo de Canfranc, Canfranc (Spain); CERN, Geneva (Switzerland); Diago, A.; Castel, J.; Dafni, T.; Herrera, D.C.; Iguaz, F.J.; Irastorza, I.G.; Luzón, G.; Mirallas, H. [Laboratorio de Física Nuclear y Astropartículas, Universidad de Zaragoza, Zaragoza (Spain); Laboratorio Subterráneo de Canfranc, Canfranc (Spain); Şahin, Ö. [Department of Physics, Uludağ University, Bursa (Turkey); Veenhof, R. [Department of Physics, Uludağ University, Bursa (Turkey); CERN, Geneva (Switzerland)

2015-11-01

We model the response of a state of the art micro-hole single-stage charge amplification device (‘microbulk’ Micromegas) in a gaseous atmosphere consisting of xenon/trimethylamine at various concentrations and pressures. The amplifying structure, made with photo-lithographic techniques similar to those followed in the fabrication of gas electron multipliers (GEMs), consisted of a 100 μm-side equilateral-triangle pattern with 50 μm-diameter holes placed at its vertexes. Once the primary electrons are guided into the holes by virtue of an optimized field configuration, avalanches develop along the 50 μm-height channels etched out of the original doubly copper-clad polyimide foil. In order to properly account for the strong field gradients at the holes' entrance as well as for the fluctuations of the avalanche process (that ultimately determine the achievable energy resolution), we abandoned the hydrodynamic framework, resorting to a purely microscopic description of the electron trajectories as obtained from elementary cross-sections. We show that achieving a satisfactory description needs additional assumptions about atom–molecule (Penning) transfer reactions and charge recombination to be made.

Fast TPC Online Tracking on GPUs and Asynchronous Data Processing in the ALICE HLT to facilitate Online Calibration

International Nuclear Information System (INIS)

Rohr, David; Gorbunov, Sergey; Krzewicki, Mikolaj; Breitner, Timo; Kretz, Matthias; Lindenstruth, Volker

2015-01-01

ALICE (A Large Heavy Ion Experiment) is one of the four major experiments at the Large Hadron Collider (LHC) at CERN, which is today the most powerful particle accelerator worldwide. The High Level Trigger (HLT) is an online compute farm of about 200 nodes, which reconstructs events measured by the ALICE detector in real-time. The HLT uses a custom online data-transport framework to distribute data and workload among the compute nodes.ALICE employs several calibration-sensitive subdetectors, e.g. the TPC (Time Projection Chamber). For a precise reconstruction, the HLT has to perform the calibration online. Online- calibration can make certain Offline calibration steps obsolete and can thus speed up Offline analysis. Looking forward to ALICE Run III starting in 2020, online calibration becomes a necessity.The main detector used for track reconstruction is the TPC. Reconstructing the trajectories in the TPC is the most compute-intense step during event reconstruction. Therefore, a fast tracking implementation is of great importance. Reconstructed TPC tracks build the basis for the calibration making a fast online-tracking mandatory.We present several components developed for the ALICE High Level Trigger to perform fast event reconstruction and to provide features required for online calibration.As first topic, we present our TPC tracker, which employs GPUs to speed up the processing, and which bases on a Cellular Automaton and on the Kalman filter. Our TPC tracking algorithm has been successfully used in 2011 and 2012 in the lead-lead and the proton-lead runs. We have improved it to leverage features of newer GPUs and we have ported it to support OpenCL, CUDA, and CPUs with a single common source code. This makes us vendor independent.As second topic, we present framework extensions required for online calibration. The extensions, however, are generic and can be used for other purposes as well. We have extended the framework to support asynchronous compute chains

GEM detector performance with innovative micro-TPC readout in high magnetic field

Directory of Open Access Journals (Sweden)

Garzia I.

2018-01-01

Full Text Available Gas detector development is one of the pillars of the research in fundamental physics. Since several years, a new concept of detectors, called Micro Pattern Gas Detector (MPGD, allowed to overcome several problems related to other types of commonly used detectors, like drift chamber and micro strips detectors, reducing the rate of discharges and providing better radiation tolerance. Among the most used MPGDs are the Gas Electron Multipliers (GEMs. Invented by Sauli in 1997, nowadays GEMs have become an important reality for particle detectors in high energy physics. Commonly deployed as fast timing detectors and triggers, their fast response, high rate capability and high radiation hardness make them also suitable as tracking detectors. The readout scheme is one of the most important features in tracking technology. Analog readout based on the calculation of the center of gravity technique allows to overcome the limit imposed by digital pads, whose spatial resolution is limited by the pitch dimensions. However, the presence of high external magnetic fields can distort the electronic cloud and affect the performance. The development of the micro-TPC reconstruction method brings GEM detectors into a new prospective, improving significantly the spatial resolutionin presence of high magnetic fields. This innovative technique allows to reconstruct the 3-dimensional particle position, as Time Projection Chamber, but within a drift gap of a few millimeters. In these report, the charge centroid and micro-TPC methods are described in details. We discuss the results of several test beams performed with planar chambers in magnetic field. These results are one of the first developments of micro-TPC technique for GEM detectors, which allows to reach unprecedented performance in a high magnetic field of 1 T.

GEM detector performance with innovative micro-TPC readout in high magnetic field

Science.gov (United States)

Garzia, I.; Alexeev, M.; Amoroso, A.; Baldini Ferroli, R.; Bertani, M.; Bettoni, D.; Bianchi, F.; Calcaterra, A.; Canale, N.; Capodiferro, M.; Cassariti, V.; Cerioni, S.; Chai, J. Y.; Chiozzi, S.; Cibinetto, G.; Cossio, F.; Cotta Ramusino, A.; De Mori, F.; Destefanis, M.; Dong, J.; Evangelisti, F.; Evangelisti, F.; Farinelli, R.; Fava, L.; Felici, G.; Fioravanti, E.; Gatta, M.; Greco, M.; Lavezzi, L.; Leng, C. Y.; Li, H.; Maggiora, M.; Malaguti, R.; Marcello, S.; Melchiorri, M.; Mezzadri, G.; Mignone, M.; Morello, G.; Pacetti, S.; Patteri, P.; Pellegrino, J.; Pelosi, A.; Rivetti, A.; Rolo, M. D.; Savrié, M.; Scodeggio, M.; Soldani, E.; Sosio, S.; Spataro, S.; Tskhadadze, E.; Verma, S.; Wheadon, R.; Yan, L.

2018-01-01

Gas detector development is one of the pillars of the research in fundamental physics. Since several years, a new concept of detectors, called Micro Pattern Gas Detector (MPGD), allowed to overcome several problems related to other types of commonly used detectors, like drift chamber and micro strips detectors, reducing the rate of discharges and providing better radiation tolerance. Among the most used MPGDs are the Gas Electron Multipliers (GEMs). Invented by Sauli in 1997, nowadays GEMs have become an important reality for particle detectors in high energy physics. Commonly deployed as fast timing detectors and triggers, their fast response, high rate capability and high radiation hardness make them also suitable as tracking detectors. The readout scheme is one of the most important features in tracking technology. Analog readout based on the calculation of the center of gravity technique allows to overcome the limit imposed by digital pads, whose spatial resolution is limited by the pitch dimensions. However, the presence of high external magnetic fields can distort the electronic cloud and affect the performance. The development of the micro-TPC reconstruction method brings GEM detectors into a new prospective, improving significantly the spatial resolutionin presence of high magnetic fields. This innovative technique allows to reconstruct the 3-dimensional particle position, as Time Projection Chamber, but within a drift gap of a few millimeters. In these report, the charge centroid and micro-TPC methods are described in details. We discuss the results of several test beams performed with planar chambers in magnetic field. These results are one of the first developments of micro-TPC technique for GEM detectors, which allows to reach unprecedented performance in a high magnetic field of 1 T.

Alpha-lipoic acid induces sodium iodide symporter expression in TPC-1 thyroid cancer cell line

International Nuclear Information System (INIS)

Choi, Hyun-Jeung; Kim, Tae Yong; Ruiz-Llorente, Sergio; Jeon, Min Ji; Han, Ji Min; Kim, Won Gu; Shong, Young Kee; Kim, Won Bae

2012-01-01

Introduction: Patients with metastatic thyroid cancers that do not uptake iodine need effective therapeutic option. Differentiation-inducing agents have been tried to restore functional expression of sodium iodide symporter (NIS) without success. Our objective was to assess the effect of alpha-lipoic acid (ALA), known as potential antioxidant, on expression of sodium iodide symporter in thyroid cancer cells. Methods: Human thyroid cancer-derived cell lines, TPC-1, were treated with ALA, and changes in NIS mRNA and protein expression were measured. ALA's effect on NIS gene promoter was evaluated, and functional NIS expression was assessed by iodide uptake assay. Results: Treatment with ALA increased NIS mRNA expression up to ten folds of control dose-dependently after 24 h of exposure. ALA increased NIS promoter activity, and increased iodide uptake by 1.6 fold. ALA induced expression of NIS protein, but had no significant effect on the plasma membrane trafficking. ALA increased phosphorylation of CREB and nuclear translocation of pCREB, and co-treatment of ALA and trichostatin A increased iodide uptake by three folds in TPC-1 cells. Conclusions: ALA is a potential agent to increase NIS transcription in TPC-1. It could be used as an adjunctive agent to increase efficacy of radioiodine therapy if combined with a strategy to increase NIS protein trafficking to cell membrane.

A Micromegas-based low-background x-ray detector coupled to a slumped-glass telescope for axion research

DEFF Research Database (Denmark)

Aznar, F.; Castel, J.; Christensen, F. E.

2015-01-01

We report on the design, construction and operation of a low background x-ray detection line composed of a shielded Micromegas detector of the microbulk technology. The detector is made from radiopure materials and is placed at the focal point of a ~ 5 cm diameter, 1.5 m focal-length, cone......-approximation Wolter I x-ray telescope (XRT) assembled from thermally-formed (or "slumped") glass substrates deposited with multilayer coatings. The system has been conceived as a technological pathfinder for the future International Axion Observatory (IAXO), as it combines two of the techniques (optic and detector...

DarkSide-20k: A 20 Tonne Two-Phase LAr TPC for Direct Dark Matter Detection at LNGS

Energy Technology Data Exchange (ETDEWEB)

Aalseth, C.E.; et al.

2017-07-25

Building on the successful experience in operating the DarkSide-50 detector, the DarkSide Collaboration is going to construct DarkSide-20k, a direct WIMP search detector using a two-phase Liquid Argon Time Projection Chamber (LArTPC) with an active (fiducial) mass of 23 t (20 t). The DarkSide-20k LArTPC will be deployed within a shield/veto with a spherical Liquid Scintillator Veto (LSV) inside a cylindrical Water Cherenkov Veto (WCV). Operation of DarkSide-50 demonstrated a major reduction in the dominant $^{39}$Ar background when using argon extracted from an underground source, before applying pulse shape analysis. Data from DarkSide-50, in combination with MC simulation and analytical modeling, shows that a rejection factor for discrimination between electron and nuclear recoils of $\\gt3\\times10^9$ is achievable. This, along with the use of the veto system, is the key to unlocking the path to large LArTPC detector masses, while maintaining an "instrumental background-free" experiment, an experiment in which less than 0.1 events (other than $\

Development of a TPC for energy and fluence references in low energies neutronic fields (from 8 keV to 5 MeV)

International Nuclear Information System (INIS)

Maire, Donovan

2015-01-01

In order to judge the measurement reliability, metrology requires to measure quantities with their uncertainties, in relation to a reference through a documented and unbroken chain of calibrations. In neutron radiation field, instrument response has to be known as a function of the neutron energy. Then detector calibrations are required using reference neutron fields. In France, primary reference neutron fields are held by the LNE-IRSN, at the Laboratory for Neutron Metrology and Dosimetry (LMDN). In order to improve reference neutron field characterization, the LNE-IRSN MIMAC μTPC has been developed. This detector is a Time Projection Chamber (TPC), using a gas at low pressure (30 mbar abs. to 1 bar abs.). Nuclear recoils are generated by neutron elastic scattering onto gas atoms. By measuring the nuclear recoil energy and scattering angle, the μTPC detector is able to measure the energy distribution of the neutron fluence between 8 keV and 5 MeV. The main challenge was to perform accurate spectrometry of neutron fields in the keV range, following a primary procedure. First of all, a metrological approach was followed in order to master every physical process taking part in the neutron detection. This approach led to develop the direct and inverse models, representing the detector response function and its inverse function respectively. Using this detailed characterization, the energy distribution of the neutron fluence has been measured for a continuous neutron field of 27 keV. The reconstructed energy is 28,2 ± 4,5 keV, the difference between μTPC integral fluence measurement and other measurement methods is less than 6%. The LNE-IRSN MIMAC μTPC system becomes the only one system able to measure simultaneously energy and fluence at energies lower than 100 keV, following a primary procedure. The project goal is then reached. These measurements at energies lower than 100 keV shows also a non-linearity between the ionization charge and the ion kinetic energy

Drift velocity studies at a time projection chamber for various water contents in the gas mixture; Driftgeschwindigkeitsstudien an einer Zeit-Projektions-Kammer (TPC) bei unterschiedlichen Wassergehalten des Kammergases

Energy Technology Data Exchange (ETDEWEB)

Stoever, F.W.

2007-03-15

For the answer of different open questions in high energy physics the construction of a linear e{sup +}e{sup -} collider with a c. m. energy of up to one TeV is prepared. With this is connected a comprehensive development on detectors, which must satisfy the requirements of the planned experiments. For the track chamber a TPC is considered. Hereby it deals with a gas-based concept, which has already been proved in past experiments and which is at time further developed by means of test chambers. The composition of the gas mixtureplays hereby an important role. Impurities of the gas mixture, especially by oxygen and water from the ambient air are a fact, which occurs every time in the development phase and can scarcely be avoided. From this arose the motivation to study directly the effects of this impurities. The object of the present thesis are correlations between drift velocity and water content in the chamber gas of a TPC.

A TPC-like readout method for high precision muon-tracking using GEM-detectors

Energy Technology Data Exchange (ETDEWEB)

Flierl, Bernhard; Biebel, Otmar; Bortfeldt, Jonathan; Hertenberger, Ralf; Klitzner, Felix; Loesel, Philipp; Mueller, Ralph [Ludwig-Maximilians-Universitaet Muenchen (Germany); Zibell, Andre [Julius-Maximilians-Universitaet Wuerzburg (Germany)

2016-07-01

Gaseous electron multiplier (GEM) detectors are well suited for tracking of charged particles. Three dimensional tracking in a single layer can be achieved by application of a time-projection-chamber like readout mode (μTPC), if the drift time of the electrons is measured and the position dependence of the arrival time is used to calculate the inclination angle of the track. To optimize the tracking capabilities for ion tracks drift gas mixtures with low drift velocity have been investigated by measuring tracks of cosmic muons in a compact setup of four GEM-detectors of 100 x 100 x 6 mm{sup 3} active volume each and an angular acceptance of -25 to 25 . The setup consists of three detectors with two-dimensional strip readout layers of 0.4 mm pitch and one detector with a single strip readout layer of 0.25 mm pitch. All strips are readout by APV25 frontend boards and the amplification stage in the detectors consists of three GEM-foils. Tracks are reconstructed by the μTPC-method in one of the detectors and are then compared to the prediction from the other three detectors defined by the center of charge in every detector. We report our study of Argon and Helium based noble gas mixtures with carbon-dioxide as quencher.

Performance of laser distance sensors for Atlas Micromegas production

Energy Technology Data Exchange (ETDEWEB)

Mueller, Ralph; Biebel, Otmar; Bortfeldt, Jonathan; Flierl, Bernhard; Hertenberger, Ralf; Loesel, Philipp; Pree, Elias [LMU Muenchen (Germany); Zibell, Andre [JMU Wuerzburg (Germany)

2015-07-01

During the second long LHC shutdown, 2018/19, the precision tracking detectors of the ATLAS muon spectrometer in the inner end caps will be replaced using Micromegas, a planar gas-detector technology. Modules of 2 m{sup 2} area are built in quadruplets from five precisely planar sandwich panels that define the anodes and the cathodes of the four active detector planes. Single plane spatial resolutions below 100 μ m are achievable when the deviation from planarity of the strip-anodes does not exceed 80 μ m RMS over the whole active area and the parallelism of the readout strips is within 30 μ m. In order to measure the dimensional accuracy of each panel, laser distance sensors to be combined with a coordinate measurement system have been investigated. One of them turned out to be capable to measure the planarity of the panels. It has a resolution of 0.3 μ m and a beam spot diameter of ∼50 μ m, which is well below 100 μ m the size of the smallest structures. For monitoring purposes during the construction process a less accurate but cheaper sensor turned out to be sufficient. We report on the performance of the sensors and their applicability to our tasks.

Radiation tolerance studies using fault injection on the Readout Control FPGA design of the ALICE TPC detector

Science.gov (United States)

Alme, J.; Fehlker, D.; Lippmann, C.; Mager, M.; Rehman, A. U.; Røed, K.; Röhrich, D.; Ullaland, K.

2013-01-01

Single Event Upsets (SEUs) are a major concern for the TPC Readout Control Unit (RCU) of the ALICE experiment. A SEU is defined as a radiation related bit-flip in a memory cell, and a SEU in the onboard SRAM based FPGA of the RCU may lead to corrupted data or, even worse, a system malfunction. The latter situation will affect the operation of the ALICE detector since it causes a premature end of data taking. Active partial reconfiguration is utilized in a dedicated reconfiguration solution on the RCU, and this makes it possible to implement fault injection. Fault injection means inserting bit flips in the configuration memory of the FPGA in a controlled laboratory environment. This paper presents the results of the fault injection study and shows how this result can be combined with SEU measurements to estimate the functional failure rate as a function of luminosity.

Performance of 20:1 multiplexer for large area charge readouts in directional dark matter TPC detectors

Science.gov (United States)

Ezeribe, A. C.; Robinson, M.; Robinson, N.; Scarff, A.; Spooner, N. J. C.; Yuriev, L.

2018-02-01

More target mass is required in current TPC based directional dark matter detectors for improved detector sensitivity. This can be achieved by scaling up the detector volumes, but this results in the need for more analogue signal channels. A possible solution to reducing the overall cost of the charge readout electronics is to multiplex the signal readout channels. Here, we present a multiplexer system in expanded mode based on LMH6574 chips produced by Texas Instruments, originally designed for video processing. The setup has a capability of reducing the number of readouts in such TPC detectors by a factor of 20. Results indicate that the important charge distribution asymmetry along an ionization track is retained after multiplexed signals are demultiplexed.

First measurement of dE/dx with a GEM-based TPC

International Nuclear Information System (INIS)

Böhmer, F.V.; Ball, M.; Dørheim, S.; Eckstein, K.; Hönle, A.; Höppner, C.; Ketzer, B.; Konorov, I.; Neubert, S.; Paul, S.; Rauch, J.; Uhl, S.; Vandenbroucke, M.; Berger, M.; Berger-Chen, J.-C.; Cusanno, F.; Fabbietti, L.; Gasik, P.; Münzer, R.; Arora, R.

2014-01-01

In this work we present the first measurement of the specific energy loss (dE/dx) and an analysis of the resulting charged-particle identification (PID) capabilities of a large-scale TPC with GEM-based gas amplification. The data has been recorded inside the FOPI spectrometer at GSI, Germany, using reactions of 1.7 GeV/c pions impinging on a carbon target. In the specific energy loss spectrum clear bands for pions, kaons, protons and deuterons are observed. The specific energy loss resolution is studied as a function of the total particle momentum and as a function of the track length. It is found to be ∼15%, consistent with expectations

First measurement of dE/dx with a GEM-based TPC

Energy Technology Data Exchange (ETDEWEB)

Böhmer, F.V., E-mail: felix.boehmer@tum.de [Technische Universität München, Physik Department E18, D-85748 Garching (Germany); Ball, M.; Dørheim, S.; Eckstein, K.; Hönle, A.; Höppner, C.; Ketzer, B.; Konorov, I.; Neubert, S.; Paul, S.; Rauch, J.; Uhl, S.; Vandenbroucke, M. [Technische Universität München, Physik Department E18, D-85748 Garching (Germany); Berger, M.; Berger-Chen, J.-C.; Cusanno, F.; Fabbietti, L.; Gasik, P.; Münzer, R. [Excellence Cluster Universe, Technische Universität München, D-85748 Garching (Germany); Arora, R. [GSI Helmholtzzentrum für Schwerionenforschung GmbH, D-64291 Darmstadt (Germany); and others

2014-02-11

In this work we present the first measurement of the specific energy loss (dE/dx) and an analysis of the resulting charged-particle identification (PID) capabilities of a large-scale TPC with GEM-based gas amplification. The data has been recorded inside the FOPI spectrometer at GSI, Germany, using reactions of 1.7 GeV/c pions impinging on a carbon target. In the specific energy loss spectrum clear bands for pions, kaons, protons and deuterons are observed. The specific energy loss resolution is studied as a function of the total particle momentum and as a function of the track length. It is found to be ∼15%, consistent with expectations.

A 4π tracking TPC magnetic spectrometer for RHIC

International Nuclear Information System (INIS)

Danby, G.; Eiseman, S.E.; Etkin, A.; Foley, K.J.; Hackenburg, R.W.; Longacre, R.S.; Love, W.A.; Morris, T.W.; Platner, E.D.; Saulys, A.C.; Van Dijk, J.H.; Lindenbaum, S.J.; Chan, C.S.; Kramer, M.A.; Zhao, K.; Biswas, N.; Kenney, P.; Piekarz, J.; Adams, D.L.; Ahmad, S.; Bonner, B.E.; Buchanan, J.A.; Chiou, C.N.; Clement, J.M.; Corcoran, M.D.; Empl, T.; Miettinen, H.E.; Mutchler, G.S.; Roberts, J.B.; Skeens, J.

1990-01-01

The primary physics objective of the 4π TPC magnetic spectrometer proposal is to search for the Quark-Gluon Plasma. In previous workshops we have discussed what the possible hadronic signatures of such a state of matter would be. Succinctly, the QGP is a direct prediction of non-perturbative QCD. Therefore the question of the existence of this new state of matter bears directly on the validity of non-perturbative QCD. However, since non-perturbative QCD has never been established, it is apparent that what may await us is a host of new phenomena that will go beyond the standard model

Micromegas Detectors for the Muon Spectrometer Upgrade of the ATLAS Experiment

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00211509

2016-01-01

Large area Micromegas (MM) detectors will be employed for the Muon Spectrometer upgrade of the ATLAS experiment at the LHC. A total surface of about $150m^2$ of the forward regions of the Muon Spectrometer will be equipped with 8 layers of MM modules. Each module covers a surface area of approximately 2 to $3 m^2$ for a total active area of $1200 m^2$. Together with the small- strips Thin Gap Chambers, they will compose the two New Small Wheels, which will replace the innermost stations of the ATLAS Endcap Muon tracking system in the planned 2018/19 shutdown. This upgrade will mantain a low pt threshold for single muons and provides excellent tracking capabilities for the HL-LHC phase. The NSW project requires fully efficient MM chambers with spatial resolution down to $100 \\mu m$, at rate capability up to about $15kHz/cm^2$ and operation in a moderate (highly inhomogeneous) magnetic field up to B=0.3 T. The required tracking capability is provided by the intrinsic spatial resolution combined with a challengi...

Micromegas Detectors for the Muon Spectrometer Upgrade of the ATLAS Experiment

CERN Document Server

Bianco, Michele; The ATLAS collaboration

2015-01-01

Large area Micromegas (MM) detectors will be employed for the Muon Spectrometer upgrade of the ATLAS experiment at the LHC. A total surface of about 150 m2 of the forward regions of the Muon Spectrometer will be equipped with 8 layers of MM modules. Each module covers a surface area of approximately 2 to 3 m$^{2}$ for a total active area of 1200 m$^{2}$. Together with the small-strips Thin Gap Chambers, they will compose the two New Small Wheels, which will replace the innermost stations of the ATLAS Endcap Muon tracking system in the planned 2018/19 shutdown. This upgrade will maintain a low pt threshold for single muons and provides excellent tracking capabilities for the HL- LHC phase. The NSW project requires fully efficient MM chambers with spatial resolution down to 100 $ \\mu m$, a rate capability up to about 15 kHz/cm$^{2}$ and operation in a moderate (highly inhomogeneous) magnetic field up to B=0.3 T. The required tracking capability is provided by the intrinsic spatial resolution combined with a cha...

Resistive Micromegas for the Muon Spectrometer Upgrade of the ATLAS Experiment

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00215987; The ATLAS collaboration

2016-01-01

Large size resistive micromegas detectors (MM) will be employed for the first time in high-energy physics experiments for the Muon Spectrometer upgrade of the ATLAS experiment at CERN. The current innermost stations of the muon endcap system, the Small Wheel, will be upgraded in 2019 to retain the good precision tracking and trigger capabilities in the high background environment expected with the upcoming luminosity increase of the LHC. Along with the small-strip Thin Gap Chambers (sTGC) the ``New Small Wheel'' will be equipped with eight layers of MM detectors arranged in multilayers of two quadruplets, for a total of about 1200 m$^2$ detection planes. All quadruplets have trapezoidal shapes with surface areas between 2 and 3 m$^2$. The MM system will provide both trigger and tracking capabilities. In order to achieve a 15% transverse momentum resolution for 1 TeV muons, a challenging mechanical precision is required in the construction for each plane of the assembled modules, with an alignment of the reado...

Experimental observation of an extremely high electron lifetime with the ICARUS-T600 LAr-TPC

CERN Document Server

Antonello, M; Benetti, P; Boffelli, F; Bubak, A; Calligarich, E; Centro, S; Cesana, A; Cieslik, K; Cline, D B; Cocco, A G; Dabrowska, A; Dermenev, A; Dolfini, R; Falcone, A; Farnese, C; Fava, A; Ferrari, A; Fiorillo, G; Gibin, D; Gninenko, S; Guglielmi, A; Haranczyk, M; Holeczek, J; Kirsanov, M; Kisiel, J; Kochanek, I; Lagoda, J; Mania, S; Menegolli, A; Meng, G; Montanari, C; Otwinowski, S; Picchi, P; Pietropaolo, F; Plonski, P; Rappoldi, A; Raselli, G L; Rossella, M; Rubbia, C; Sala, P; Scaramelli, A; Segreto, E; Sergiampietri, F; Stefan, D; Sulej, R; Szarska, M; Terrani, M; Torti, M; Varanini, F; Ventura, S; Vignoli, C; Wang, H; Yang, X; Zalewska, A; Zani, A; Zaremba, K

2014-01-01

The ICARUS T600 detector, the largest liquid Argon Time Projection Chamber (LAr-TPC) realized after many years of RD activities, was installed and successfully operated for 3 years at the INFN Gran Sasso underground Laboratory. One of the most important issues was the need of an extremely low residual electronegative impurity content in the liquid Argon, in order to transport the free electrons created by the ionizing particles with a very small attenuation along the drift path. The solutions adopted for the Argon re-circulation and purification systems have permitted to reach impressive results in terms of Argon purity and a free electron lifetime exceeding 15 ms, corresponding to about 20 parts per trillion of equivalent O2 contamination, a milestone for any future project involving LAr-TPC's and the development of higher detector mass scales.

Two large-area anode-pad MICROMEGAS chambers as the basic elements of a pre-shower detector

CERN Document Server

Aphecetche, L; D'Enterria, D G; Le Guay, M; Li, X; Martínez, G; Mora, M J; Pichot, P; Roy, D; Schutz, Y

2001-01-01

The design of a detector based on MICROMEGAS (MICRO MEsh GAseous Structure) technology is presented. Our detector is characterized by a large active area of 398(\\times)281 mm(^{2}), a pad read-out with 20(\\times)22 mm(^{2}) segmentation, and an uniform amplification gap obtained by insulating spacers (100 (\\mu)m high and 200 (\\mu)m in diameter). The performances of several prototypes have been evaluated under irradiation with secondary beams of 2 GeV/c momentum charged pions and electrons. We consider such a detector as the basic element for a pre-shower detector to equip the PHOton Spectrometer (PHOS) of the ALICE experiment. Its assets are modularity, small amount of material, robustness and low cost.

DarkSide-20k: A 20 tonne two-phase LAr TPC for direct dark matter detection at LNGS

Science.gov (United States)

Aalseth, C. E.; Acerbi, F.; Agnes, P.; Albuquerque, I. F. M.; Alexander, T.; Alici, A.; Alton, A. K.; Antonioli, P.; Arcelli, S.; Ardito, R.; Arnquist, I. J.; Asner, D. M.; Ave, M.; Back, H. O.; Barrado Olmedo, A. I.; Batignani, G.; Bertoldo, E.; Bettarini, S.; Bisogni, M. G.; Bocci, V.; Bondar, A.; Bonfini, G.; Bonivento, W.; Bossa, M.; Bottino, B.; Boulay, M.; Bunker, R.; Bussino, S.; Buzulutskov, A.; Cadeddu, M.; Cadoni, M.; Caminata, A.; Canci, N.; Candela, A.; Cantini, C.; Caravati, M.; Cariello, M.; Carlini, M.; Carpinelli, M.; Castellani, A.; Catalanotti, S.; Cataudella, V.; Cavalcante, P.; Cavuoti, S.; Cereseto, R.; Chepurnov, A.; Cicalò, C.; Cifarelli, L.; Citterio, M.; Cocco, A. G.; Colocci, M.; Corgiolu, S.; Covone, G.; Crivelli, P.; D'Antone, I.; D'Incecco, M.; D'Urso, D.; Da Rocha Rolo, M. D.; Daniel, M.; Davini, S.; de Candia, A.; De Cecco, S.; De Deo, M.; De Filippis, G.; De Guido, G.; De Rosa, G.; Dellacasa, G.; Della Valle, M.; Demontis, P.; Derbin, A.; Devoto, A.; Di Eusanio, F.; Di Pietro, G.; Dionisi, C.; Dolgov, A.; Dormia, I.; Dussoni, S.; Empl, A.; Fernandez Diaz, M.; Ferri, A.; Filip, C.; Fiorillo, G.; Fomenko, K.; Franco, D.; Froudakis, G. E.; Gabriele, F.; Gabrieli, A.; Galbiati, C.; Garcia Abia, P.; Gendotti, A.; Ghisi, A.; Giagu, S.; Giampa, P.; Gibertoni, G.; Giganti, C.; Giorgi, M. A.; Giovanetti, G. K.; Gligan, M. L.; Gola, A.; Gorchakov, O.; Goretti, A. M.; Granato, F.; Grassi, M.; Grate, J. W.; Grigoriev, G. Y.; Gromov, M.; Guan, M.; Guerra, M. B. B.; Guerzoni, M.; Gulino, M.; Haaland, R. K.; Hallin, A.; Harrop, B.; Hoppe, E. W.; Horikawa, S.; Hosseini, B.; Hughes, D.; Humble, P.; Hungerford, E. V.; Ianni, An.; Jillings, C.; Johnson, T. N.; Keeter, K.; Kendziora, C. L.; Kim, S.; Koh, G.; Korablev, D.; Korga, G.; Kubankin, A.; Kuss, M.; Kuźniak, M.; La Commara, M.; Lehnert, B.; Li, X.; Lissia, M.; Lodi, G. U.; Loer, B.; Longo, G.; Loverre, P.; Lussana, R.; Luzzi, L.; Ma, Y.; Machado, A. A.; Machulin, I. N.; Mandarano, A.; Mapelli, L.; Marcante, M.; Margotti, A.; Mari, S. M.; Mariani, M.; Maricic, J.; Martoff, C. J.; Mascia, M.; Mayer, M.; McDonald, A. B.; Messina, A.; Meyers, P. D.; Milincic, R.; Moggi, A.; Moioli, S.; Monroe, J.; Monte, A.; Morrocchi, M.; Mount, B. J.; Mu, W.; Muratova, V. N.; Murphy, S.; Musico, P.; Nania, R.; Navrer Agasson, A.; Nikulin, I.; Nosov, V.; Nozdrina, A. O.; Nurakhov, N. N.; Oleinik, A.; Oleynikov, V.; Orsini, M.; Ortica, F.; Pagani, L.; Pallavicini, M.; Palmas, S.; Pandola, L.; Pantic, E.; Paoloni, E.; Paternoster, G.; Pavletcov, V.; Pazzona, F.; Peeters, S.; Pelczar, K.; Pellegrini, L. A.; Pelliccia, N.; Perotti, F.; Perruzza, R.; Pesudo, V.; Piemonte, C.; Pilo, F.; Pocar, A.; Pollmann, T.; Portaluppi, D.; Pugachev, D. A.; Qian, H.; Radics, B.; Raffaelli, F.; Ragusa, F.; Razeti, M.; Razeto, A.; Regazzoni, V.; Regenfus, C.; Reinhold, B.; Renshaw, A. L.; Rescigno, M.; Retière, F.; Riffard, Q.; Rivetti, A.; Rizzardini, S.; Romani, A.; Romero, L.; Rossi, B.; Rossi, N.; Rubbia, A.; Sablone, D.; Salatino, P.; Samoylov, O.; Sánchez García, E.; Sands, W.; Sanfilippo, S.; Sant, M.; Santorelli, R.; Savarese, C.; Scapparone, E.; Schlitzer, B.; Scioli, G.; Segreto, E.; Seifert, A.; Semenov, D. A.; Shchagin, A.; Shekhtman, L.; Shemyakina, E.; Sheshukov, A.; Simeone, M.; Singh, P. N.; Skensved, P.; Skorokhvatov, M. D.; Smirnov, O.; Sobrero, G.; Sokolov, A.; Sotnikov, A.; Speziale, F.; Stainforth, R.; Stanford, C.; Suffritti, G. B.; Suvorov, Y.; Tartaglia, R.; Testera, G.; Tonazzo, A.; Tosi, A.; Trinchese, P.; Unzhakov, E. V.; Vacca, A.; Vázquez-Jáuregui, E.; Verducci, M.; Viant, T.; Villa, F.; Vishneva, A.; Vogelaar, B.; Wada, M.; Wahl, J.; Walding, J.; Wang, H.; Wang, Y.; Watson, A. W.; Westerdale, S.; Williams, R.; Wojcik, M. M.; Wu, S.; Xiang, X.; Xiao, X.; Yang, C.; Ye, Z.; Yllera de Llano, A.; Zappa, F.; Zappalà, G.; Zhu, C.; Zichichi, A.; Zullo, M.; Zullo, A.; Zuzel, G.

2018-03-01

Building on the successful experience in operating the DarkSide-50 detector, the DarkSide Collaboration is going to construct DarkSide-20k, a direct WIMP search detector using a two-phase Liquid Argon Time Projection Chamber (LAr TPC) with an active (fiducial) mass of 23 t (20 t). This paper describes a preliminary design for the experiment, in which the DarkSide-20k LAr TPC is deployed within a shield/veto with a spherical Liquid Scintillator Veto (LSV) inside a cylindrical Water Cherenkov Veto (WCV). This preliminary design provides a baseline for the experiment to achieve its physics goals, while further development work will lead to the final optimization of the detector parameters and an eventual technical design. Operation of DarkSide-50 demonstrated a major reduction in the dominant 39Ar background when using argon extracted from an underground source, before applying pulse shape analysis. Data from DarkSide-50, in combination with MC simulation and analytical modeling, shows that a rejection factor for discrimination between electron and nuclear recoils of >3 × 109 is achievable. This, along with the use of the veto system and utilizing silicon photomultipliers in the LAr TPC, are the keys to unlocking the path to large LAr TPC detector masses, while maintaining an experiment in which less than < 0.1 events (other than ν-induced nuclear recoils) is expected to occur within the WIMP search region during the planned exposure. DarkSide-20k will have ultra-low backgrounds than can be measured in situ, giving sensitivity to WIMP-nucleon cross sections of 1.2 × 10^{-47} cm2 (1.1 × 10^{-46} cm2) for WIMPs of 1 TeV/c 2 (10 TeV/c 2) mass, to be achieved during a 5 yr run producing an exposure of 100 t yr free from any instrumental background.

Effect of drag-reducing polymers on Tubing Performance Curve (TPC) in vertical gas-liquid flows

NARCIS (Netherlands)

Shoeibi Omrani, P.; Veltin, J.; Turkenburg, D.H.

2014-01-01

This paper discusses the effect of drag reducing polymers on the Tubing Performance Curve (TPC) of vertical air-water flows at near atmospheric conditions. The effect of polymer concentration, liquid and gas flow rates on the pressure drop curve (Tubing Performance Curve) was investigated

First performance results of the ALICE TPC Readout Control Unit 2

OpenAIRE

Zhao, Chengxin; Alme, Johan; Alt, Torsten; Appelshäuser, Harald; Bratrud, Lars Karlot Stubberud; Castro, Andrew; Costa, Filippo; David, Ernö; Gunji, Tako; Kirsch, S; Kiss, Tivadar; Langøy, Rune; Lien, Jørgen; Lippmann, C; Oskarsson, Anders

2016-01-01

- This paper presents the first performance results of the ALICE TPC Readout Control Unit 2 (RCU2). With the upgraded hardware typology and the new readout scheme in FPGA design, the RCU2 is designed to achieve twice the readout speed of the present Readout Control Unit. Design choices such as using the flash-based Microsemi Smartfusion2 FPGA and applying mitigation techniques in interfaces and FPGA design ensure a high degree of radiation tolerance. This paper presents the system level ir...

Flow and spectra for light fragments from Au+Au collisions in the EOS TPC

International Nuclear Information System (INIS)

Lisa, M.A.

1997-01-01

We study the effects of the collective motion (flow) on distributions and yields of light fragments produced in heavy ion collisions at the Bevalac/SIS energy range. p, d, t, 3 He and α fragments emitted from Au+Au collisions at 0.25 - 1.15 AGeV bombarding energy were measured with the EOS TPC. The TPC has high and seamless acceptance in the forward hemisphere of the CM system, and excellent particle identification for light fragments. Analyses of the sidewards flow, squeeze-out, and radial flow signals are presented as a function of bombarding energy and centrality of the collision. The fragment mass systematics of the flow signals are seen to be consistent with a simple coalescence picture for the light particles studied. A unifying framework for describing many of the systematic features of the different types of flow (e.g. the p T dependence of squeeze-out) in terms of 3 parameters is discussed. Consistent with previous studies, the parameter describing squeeze-out is seen to be most sensitive to the Equation of State within a Quantum Molecular Dynamics (QMD) model. The effect on extracted temperature of various radial flow profiles is discussed. Finally, a preliminary study of light particle yields in terms of the Quantum Statistical Model (QSM) is presented. It is found that the beam energy dependence of the 'chemical' temperature obtained from the yields tracks with the 'kinetic' temperature obtained from the spectral fits, if one accounts for a flow profile. However, discrepancies between different implementations (computer codes) of the QSM must be resolved before drawing final conclusions about agreement. (authors)

PandaX-III: Searching for neutrinoless double beta decay with high pressure 136Xe gas time projection chambers

Science.gov (United States)

Chen, Xun; Fu, ChangBo; Galan, Javier; Giboni, Karl; Giuliani, Franco; Gu, LingHui; Han, Ke; Ji, XiangDong; Lin, Heng; Liu, JiangLai; Ni, KaiXiang; Kusano, Hiroki; Ren, XiangXiang; Wang, ShaoBo; Yang, Yong; Zhang, Dan; Zhang, Tao; Zhao, Li; Sun, XiangMing; Hu, ShouYang; Jian, SiYu; Li, XingLong; Li, XiaoMei; Liang, Hao; Zhang, HuanQiao; Zhao, MingRui; Zhou, Jing; Mao, YaJun; Qiao, Hao; Wang, SiGuang; Yuan, Ying; Wang, Meng; Khan, Amir N.; Raper, Neill; Tang, Jian; Wang, Wei; Dong, JiaNing; Feng, ChangQing; Li, Cheng; Liu, JianBei; Liu, ShuBin; Wang, XiaoLian; Zhu, DanYang; Castel, Juan F.; Cebrián, Susana; Dafni, Theopisti; Garza, Javier G.; Irastorza, Igor G.; Iguaz, Francisco J.; Luzón, Gloria; Mirallas, Hector; Aune, Stephan; Berthoumieux, Eric; Bedfer, Yann; Calvet, Denis; d'Hose, Nicole; Delbart, Alain; Diakaki, Maria; Ferrer-Ribas, Esther; Ferrero, Andrea; Kunne, Fabienne; Neyret, Damien; Papaevangelou, Thomas; Sabatié, Franck; Vanderbroucke, Maxence; Tan, AnDi; Haxton, Wick; Mei, Yuan; Kobdaj, Chinorat; Yan, Yu-Peng

2017-06-01

Searching for the neutrinoless double beta decay (NLDBD) is now regarded as the topmost promising technique to explore the nature of neutrinos after the discovery of neutrino masses in oscillation experiments. PandaX-III (particle and astrophysical xenon experiment III) will search for the NLDBD of 136Xe at the China Jin Ping Underground Laboratory (CJPL). In the first phase of the experiment, a high pressure gas Time Projection Chamber (TPC) will contain 200 kg, 90% 136Xe enriched gas operated at 10 bar. Fine pitch micro-pattern gas detector (Microbulk Micromegas) will be used at both ends of the TPC for the charge readout with a cathode in the middle. Charge signals can be used to reconstruct the electron tracks of the NLDBD events and provide good energy and spatial resolution. The detector will be immersed in a large water tank to ensure 5 m of water shielding in all directions. The second phase, a ton-scale experiment, will consist of five TPCs in the same water tank, with improved energy resolution and better control over backgrounds.

Magnetic Field Requirements for a Detector at the Linear Collider Using a TPC as Main Tracking Device

CERN Document Server

Klempt, W

2010-01-01

This note describes the requirements to the magnetic field which occur in an ILD like detector at ILC or CLIC. In particular we describe requirements introduced by choosing a TPC as main tracking detector.

Large resistive 2D Micromegas with genetic multiplexing and some imaging applications

Science.gov (United States)

Bouteille, S.; Attié, D.; Baron, P.; Calvet, D.; Magnier, P.; Mandjavidze, I.; Procureur, S.; Riallot, M.

2016-10-01

The performance of the first large resistive Micromegas detectors with 2D readout and genetic multiplexing is presented. These detectors have a 50 × 50cm2 active area and are equipped with 1024 strips both in X- and Y-directions. The same genetic multiplexing pattern is applied on both coordinates, resulting in the compression of signals on 2 × 61 readout channels. Four such detectors have been built at CERN, and extensively tested with cosmics. The resistive strip film allows for very high gain operation, compensating for the charge spread on the 2 dimensions as well as the S / N loss due to the huge, 1 nF input capacitance. This film also creates a significantly different signal shape in the X- and Y-coordinates due to the charge evacuation along the resistive strips. All in all a detection efficiency above 95% is achieved with a 1 cm drift gap. Though not yet optimal, the measured 300 μm spatial resolution allows for very precise imaging in the field of muon tomography, and some applications of these detectors are presented.

Investigation of a Huffman-based compression algorithm for the ALICE TPC read-out in LHC Run 3

Energy Technology Data Exchange (ETDEWEB)

Klewin, Sebastian [Physikalisches Institut, University of Heidelberg (Germany); Collaboration: ALICE-Collaboration

2016-07-01

Within the scope of the ALICE upgrade towards the Run 3 of the Large Hadron Collider at CERN, starting in 2020, the ALICE Time Projection Chamber (TPC) will be reworked in order to allow for a continuous read-out. This rework includes not only a replacement of the current read-out chambers with Gas Electron Multiplier (GEM) technology, but also new front-end electronics. To be able to read out the whole data stream without loosing information, in particular without zero-suppression, a lossless compression algorithm, the Huffman encoding, was investigated and adapted to the needs of the TPC. In this talk, an algorithm, adapted for an FPGA implementation, is presented. We show its capability to reduce the data volume to less than 40% of its original size.

A Continuously Running High-Rate GEM-TPC for P-bar ANDA

International Nuclear Information System (INIS)

Boehmer, F.V.; Angerer, H.; Dorheim, S.; Hoeppner, C.; Ketzer, B.; Konorov, I.; Neubert, S.; Paul, S.; Vandenbroucke, M.; Zhang, X.; Berger, M.; Cusanno, F.; Fabbietti, L.; Lalik, R.; Beck, R.; Kaiser, D.; Lang, M.; Schmitz, R.; Walther, D.; Winnebeck, A.

2011-01-01

The P-bar ANDA fixed target experiment planned at FAIR will investigate fundamental questions of non-perturbative QCD. It makes use of a cooled antiproton beam (momentum: 1.5 to 15GeV/c) and will reach luminosities of up to 2.10 32 cm -2 s -1 , yielding a p-bar p-annihilation rate of 2.10 7 s -1 . One option for the central tracker of P-bar ANDA is a cylindrical, ungated, continuously running TPC with GEM-based gas amplification stage.

ALICE TPC gas system is the first of the LHC experiments to be put on line

CERN Document Server

Maximilien Brice

2006-01-01

Picture 01 : the Physics Department's DT1 gas systems team in their laboratory. Picture 02 : Chilo Garabatos (ALICE) and Stefan Haider (PH-DT1-GS) in front of the gas system for the ALICE TPC which has just been put on line.

A Continuously Running High-Rate GEM-TPC for P-bar ANDA

Energy Technology Data Exchange (ETDEWEB)

Boehmer, F.V., E-mail: felix.valentin.boehmer@cern.ch [Technische Universitaet Muenchen Physik Department, James-Franck-Strasse, 85748 Garching (Germany); Angerer, H.; Dorheim, S.; Hoeppner, C.; Ketzer, B.; Konorov, I.; Neubert, S.; Paul, S.; Vandenbroucke, M.; Zhang, X. [Technische Universitaet Muenchen Physik Department, James-Franck-Strasse, 85748 Garching (Germany); Berger, M.; Cusanno, F.; Fabbietti, L.; Lalik, R. [Excellence Cluster Universe, Muenchen (Germany); Beck, R.; Kaiser, D.; Lang, M.; Schmitz, R.; Walther, D.; Winnebeck, A. [Helmholtz-Institut fuer Strahlen- und Kernphysik, Bonn (Germany)

2011-06-15

The P-bar ANDA fixed target experiment planned at FAIR will investigate fundamental questions of non-perturbative QCD. It makes use of a cooled antiproton beam (momentum: 1.5 to 15GeV/c) and will reach luminosities of up to 2.10{sup 32}cm{sup -2}s{sup -1}, yielding a p-bar p-annihilation rate of 2.10{sup 7}s{sup -1}. One option for the central tracker of P-bar ANDA is a cylindrical, ungated, continuously running TPC with GEM-based gas amplification stage.

The efficacy of Jackson drain in the application to be a tunnel pleural catheter (TPC) in the management of malignant pleural effusion.

Science.gov (United States)

Tscheikuna, Jamsak; Thomrongpairoj, Preecha; Disayabutr, Suppareurg

2011-06-01

Malignant pleural effusion (MPE) is a common clinical problem in patients with advanced cancer and portends a poor prognosis, which means survival of less than six months. In June 1997, the US-FDA approved an indwelling TPC with a one-way drainage valve to be used in the management of MPE. Although popularity of this TPC has increased over the past few years, the experience with this device remains limited in Thai patients. One of the reasons is its high cost. Assess the efficacy and the safety of customary indwelling TPC by using Jackson drain in the management of patients with symptomatic MPE. Ten patients with symptomatic MPE were receiving these catheters (18 Fr Silicone catheters with 25 cm fenestrated length) to drain effusion via plastic vacuum bottles (250 ml) every other day or as needed to relieve dyspnea. The patient's dyspnic respiration, quality of life, and comfort during the catheter's application were quantified with a Borg score, the St. George Respiratory Disease Questionnaire (SGRQ), and the comfort's score, respectively. These parameters were recorded at initial (before insertion) and 2-week follow-up visit. Pain after 24 hours of each insertion was quantified by visual pain analogue scale (VPAS). Patients were followed until either death or catheter removal. The Borg score, SGRQ, and comfort's score showed significant improvement at 2-week visit (p drain was effective in the treatment of MPE as a TPC without early complications.

Design of the ATLAS New Small Wheel Gas Leak Tightness Station for the Micromegas Detector Modules

CERN Document Server

Gazis, Evangelos; The ATLAS collaboration

2017-01-01

In this work we describe advanced data processing and analysis techniques intended to be used in the gas tightness station at CERN for Quality Assurance and Quality Control of the New Small Wheel Micromegas Quadruplets. We combine two methods: a conventional one based on the Pressure Decay Rate and an alternative-novel one, based on the Flow Rate Loss. A prototype setup has been developed based on a Lock-in Amplifier device and should be operated in conjunction with the gas leak test via the Flow Rate Loss. Both methods have been tested by using emulated leak branches based on specific thin medical needles. The semi-automatic data acquisition, monitoring and processing system is presented also in this work while a more sophisticated environment based on the WinCC-OA SCADA is under development.

Search for a QGP with a TPC spectrometer, and QGP signals predicted by new event generator

International Nuclear Information System (INIS)

Lindenbaum, S.J.

1988-01-01

The BNL/CCNY/Johns Hopkins/Rice Collaboration has developed and successfully tested a TPC Magnetic Spectrometer to search for OGP signals produced by ion beams at AGS. Test data with 14.5 GeV/c /times/ A Oxygen ions incident on a Pb target has been obtained. These include a 78-prong nuclear interaction in the MPS magnet which was pattern recognized with an efficiency ∼75%. A cascade and plasma event generator has also been developed, the predictions of which are used to illustrate how our technique can detect possible plasma signals at AGS and RHIC. A 4π tracking TPC magnetic spectrometer has been proposed for RHIC. The new event generator predicts striking central rapidity bump QGP signals at RHIC for p, /bar p/, π/sup +-/, K/sup +-/, etc., produced by 100 GeV/c /times/ A Au on Au collisions and these are presented. 2 refs., 13 figs., 1 tab

Topological signature in the NEXT high pressure xenon TPC

Science.gov (United States)

Ferrario, Paola; NEXT Collaboration

2017-09-01

The NEXT experiment aims to observe the neutrinoless double beta decay of 136Xe in a high-pressure xenon gas TPC using electroluminescence to amplify the signal from ionization. One of the main advantages of this technology is the possibility to use the topology of events with energies close to Qββ as an extra tool to reject background. In these proceedings we show with data from prototypes that an extra background rejection factor of 24.3 ± 1.4 (stat.)% can be achieved, while maintaining an efficiency of 66.7 ± 1.% for signal events. The performance expected in NEW, the next stage of the experiment, is to improve to 12.9% ± 0.6% background acceptance for 66.9% ± 0.6% signal efficiency.

The WA105-3x1x1 m3 dual phase LAr-TPC demonstrator

CERN Document Server

Murphy, Sebastien

2016-11-15

The dual phase Liquid Argon Time Projection Chamber (LAr TPC) is the state-of-art technology for neutrino detection thanks to its superb 3D tracking and calorimetry performance. Its main feature is the charge amplification in gas argon which provides excellent signal-to-noise ratio. Electrons produced in the liquid argon are extracted in the gas phase. Here, a readout plane based on Large Electron Multiplier detectors provides amplification of the charges before its collection onto an anode with strip readout. The charge amplification enables constructing fully homoge- nous giant LAr-TPCs with tuneable gain, excellent charge imaging performance and increased sensitivity to low energy events. Following a staged approach the WA105 collaboration is con- structing a dual phase LAr-TPC with an active volume of 3x1x1m3 that will soon be tested with cosmic rays. Its construction and operation aims to test scalable solutions for the crucial aspects of this technology: ultra high argon purity in non-evacuable tank, la...

Micromegas detector for $^{33}$S(n,$\\alpha$) cross section measurement at n_TOF

CERN Multimedia

The present proposal is a consequence of the successful tests performed in 2011 related to the Letter of Intent CERN-INTC-2010-023/I-092. The main goal of this proposal is a first (n,$\\alpha$) cross section measurement with the Micromegas detector presently running at n_TOF for monitoring purposes and fission cross section measurements. The $^{33}$S(n,$\\alpha$) cross section is of interest in astrophysics mainly due to the origin of $^{36}$S which is still an open question. $^{33}$S is also of interest in medical physics since it has been proposed as a possible/alternative cooperating target to boron neutron capture therapy. Important discrepancies between previous measurements of $^{33}$S(n,$\\alpha$) cross section and especially between the resonance parameters are found in the literature. We propose to measure the (n,$\\alpha$) cross section of the stable isotope $^{33}$S in the energy range up to 300 keV covering the astrophysical range of interest. The possibility of increasing this energy range will be st...

Assessment of the efficiency of SimPlate™ total plate count color indicator (TPC CI to quantify mesophilic aerobic microorganisms in pasteurized milk Avaliação da eficiência do SimPlate™ Total Plate Count Color Indicator (TPC CI para enumeração de microrganismos aeróbios mesófilos em leite pasteurizado

Directory of Open Access Journals (Sweden)

Luís Augusto Nero

2002-01-01

Full Text Available The SimPlate™ TPC CI system is a rapid method to count mesophilic aerobic microorganisms (MAM in foods, based on the use of resazurine to indicate bacterial growth. Its efficiency in pasteurized milk was evaluated using 142 pasteurized milk samples (38 type A, 43 type B and 61 type C collected in Londrina, PR. The standard plating method, using Plate Count Agar (PCA was used for comparison. The plates of both systems were incubated at 35ºC and read after 24h and 48h. The occurrence of false-positive and false-negative wells and the predominant microorganisms in them were also evaluated. The results were compared by simple correlation and mean variance analyses. The correlation (r and mean variance values were 0.6811 and 0.7583 for the results obtained after 24h, respectively, and 0.9126 and 0.0842 for the results obtained after 48h, respectively. These results indicate that the performance of the system increases when the plates are incubated for 48h. When the three types of milk were evaluated separately, these values were 0.9285 and 0.0817 for type A milk, 0.9231 and 0.0466 for type B milk and 0.7209 and 0.1082 for type C milk. These results indicate that the better the quality of the milk the better the performance of SimPlate™ TPC CI. False-negative wells, found more frequently in samples with high MAM counts, were caused by Gram positive microorganisms, poorly detected by the SimPlate™ TPC CI system because they grew slowly and had low reduction capacity. The results indicated a higher efficiency of the SimPlate™ TPC CI system in the reading at 48h.O sistema SimPlate™ TPC CI é um método rápido para enumeração de microrganismos aeróbios mesófilos (MAM em alimentos que utiliza a resazurina como substância indicadora de crescimento bacteriano. Para avaliar sua eficiência em leite pasteurizado, 142 amostras (38 de leite tipo A, 43 de leite tipo B e 61 de leite tipo C foram colhidas em Londrina, PR, e analisadas pelo Sim

Silicon ion interactions measured in the E-810 TPC at the AGS

International Nuclear Information System (INIS)

Love, W.A.; Eiseman, S.E.; Etkin, A.; Foley, K.J.; Hackenburg, R.W.; Longacre, R.S.; Morris, T.W.; Platner, E.D.; Saulys, A.C.; Bonner, B.E.; Buchanan, J.A.; Chiou, C.N.; Clement, J.M.; Corcoran, M.D.; Kruk, J.W.; Mutchler, G.S.; Nessi, M.; Nessi-Tedaldi, F.; Roberts, J.B.; Chan, C.S.; Kramer, M.A.; Zhao, K.; Hallman, T.J.; Madansky, L.; Lindenbaum, S.J.

1991-01-01

The tracking detector of AGS Experiment 810 is a three-piece Time Projection Chamber (TPC) which measures all charged tracks in the forward hemisphere of the nucleon-nucleon center of mass system, i.e. forward of 20 degrees in the lab. A cut at multiplicity 50 was used to select more central collisions, yielding 2291 events from the gold sample, 2170 from the copper. This corresponds to cross sections of 0.59 and 0.20 barns, respectively, defining the 'central' sample for the charged particle distributions presented here. (orig./HSI)

τ physics using the TPC/2γ facility at HiLum PEP

International Nuclear Information System (INIS)

Bloom, E.D.

1991-01-01

Plans for a TPC/2γ facility program using HiLum PEP for τ physics are presented. The detector and its performance are described in some detail. The possibilities for a τ physics program with an integrated luminosity of 1 fb -1 are discussed. The physics issues are reviewed, particularly the τ'1-prong' problem, and preliminary results on τ → ν τ K +- X + X - + ≥ 0 Neutrals are shown. The performance of HiLum PEP is also presented, and expectations for the future are discussed. (R.P.) 15 refs., 14 figs., 3 tabs

The ALICE TPC, a large 3-dimensional tracking device with fast readout for ultra-high multiplicity events

CERN Document Server

INSPIRE-00249819; Appelshauser, H.; Bablok, S.; Bialas, N.; Bolgen, R.; Bonnes, U.; Bramm, R.; Braun-Munzinger, P.; Campagnolo, R.; Christiansen, P.; Dobrin, A.; Engster, C.; Fehlker, D.; Foka, Y.; Frankenfeld, U.; Gaardhoje, J.J.; Garabatos, C.; Glassel, P.; Gonzalez Gutierrez, C.; Gros, P.; Gustafsson, H.A.; Helstrup, H.; Hoch, M.; Ivanov, M.; Janik, R.; Junique, A.; Kalweit, A.; Keidel, R.; Kniege, S.; Kowalski, M.; Larsen, D.T.; Lesenechal, Y.; Lenoir, P.; Lindegaard, N.; Lippmann, C.; Mager, M.; Mast, M.; Matyja, A.; Munkejord, M.; Musa, L.; Nielsen, B.S.; Nikolic, V.; Oeschler, H.; Olsen, E.K.; Oskarsson, A.; Osterman, L.; Pikna, M.; Rehman, A.; Renault, G.; Renfordt, R.; Rossegger, S.; Rohrich, D.; Roed, K.; Richter, M.; Rueshmann, G.; Rybicki, A.; Sann, H.; Schmidt, H.R.; Siska, M.; Sitar, B.; Soegaard, C.; Soltveit, H.K.; Soyk, D.; Stachel, J.; Stelzer, H.; Stenlund, E.; Stock, R.; Strmen, P.; Szarka, I.; Ullaland, K.; Vranic, D.; Veenhof, R.; Westergaard, J.; Wiechula, J.; Windelband, B.

2010-01-01

The design, construction, and commissioning of the ALICE Time-Projection Chamber (TPC) is described. It is the main device for pattern recognition, tracking, and identification of charged particles in the ALICE experiment at the CERN LHC. The TPC is cylindrical in shape with a volume close to 90 m^3 and is operated in a 0.5 T solenoidal magnetic field parallel to its axis. In this paper we describe in detail the design considerations for this detector for operation in the extreme multiplicity environment of central Pb--Pb collisions at LHC energy. The implementation of the resulting requirements into hardware (field cage, read-out chambers, electronics), infrastructure (gas and cooling system, laser-calibration system), and software led to many technical innovations which are described along with a presentation of all the major components of the detector, as currently realized. We also report on the performance achieved after completion of the first round of stand-alone calibration runs and demonstrate result...

Space charge calibration of the ALICE TPC operated with an open gating grid

Energy Technology Data Exchange (ETDEWEB)

Hellbaer, Ernst [Institut fuer Kernphysik, Goethe-Universitaet Frankfurt (Germany); Ivanov, Marian [GSI (Germany); Wiechula, Jens [Universitaet Tuebingen (Germany); Collaboration: ALICE-Collaboration

2015-07-01

The Time Projection Chamber (TPC) is the main particle identification detector of the ALICE experiment at the CERN LHC. High interaction rates of 50 kHz in Pb-Pb during the Run 3 period after 2020 require a major upgrade of the TPC readout. The currently used Multiwire Proportional Chambers (MWPCs) will be replaced by readout chambers (ROCs) based on Gas Electron Multiplier (GEM) technology which will be operated in a continuous mode. While the gating grid of the MWPCs prevents the positive ions of the amplification region from entering the drift volume, the GEM-based ROCs will introduce an ion backflow (IBF) of about 1%. In combination with the high-luminosity environment, this amount of back-drifting ions results in a considerable space charge density which distorts the drift path of the primary ionisation electrons significantly. In order to still provide a high tracking efficiency and cluster-to-track association, an efficient calibration scheme will be implemented. As a test ground for the new calibration scheme, pp collision data was taken during Run 1 with the gating grid operated in a transparent mode allowing the ions to enter the drift volume. The measured space point distortions due to the space charge are presented together with the corrected data and compared to simulations for Run 3.

Amplification and scintillation properties of oxygen-rich gas mixtures for optical-TPC applications

International Nuclear Information System (INIS)

Weissman, L; Gai, M; Breskin, A; Chechik, R; Dangendorf, V; Tittelmeier, K; Weller, H R

2006-01-01

We studied electron amplification and light emission from avalanches in oxygen-containing gas mixtures. The mixtures investigated in this work included, among others, CO 2 and N 2 O mixed with Triethylamine (TEA) or N 2 . Double-Step Parallel Gap (DSPG) multipliers and THick Gas Electron Multipliers (THGEM) were investigated. High light yields were measured from CO 2 + N 2 and CO 2 + TEA, though with different emission spectra. We observed the characteristic wave-length emission of N 2 and of TEA and used a polymer wave-length shifter to convert TEA UV-light into the visible spectrum. The results of these measurements indicate the applicability of optical recording of ionizing tracks in a TPC target-detector designed to study the cross-sections of the 16 O(γ, α) 12 C reaction, a central problem in nuclear astrophysics

GOSSIP: A vertex detector combining a thin gas layer as signal generator with a CMOS readout pixel array

Energy Technology Data Exchange (ETDEWEB)

Campbell, M. [CERN/MediPix Consortium, Geneva (Switzerland); Heijne, E.H.M. [CERN/MediPix Consortium, Geneva (Switzerland); Llopart, X. [CERN/MediPix Consortium, Geneva (Switzerland); Colas, P. [DAPNIA, CEA Saclay, 91191 Gif sur Yvette Cedex (France); Giganon, A. [DAPNIA, CEA Saclay, 91191 Gif sur Yvette Cedex (France); Giomataris, Y. [DAPNIA, CEA Saclay, 91191 Gif sur Yvette Cedex (France); Chefdeville, M. [NIKHEF, Amsterdam (Netherlands); Colijn, A.P. [NIKHEF, Amsterdam (Netherlands); Fornaini, A. [NIKHEF, Amsterdam (Netherlands); Graaf, H. van der [NIKHEF, Amsterdam (Netherlands)]. E-mail: vdgraaf@nikhef.nl; Kluit, P. [NIKHEF, Amsterdam (Netherlands); Timmermans, J. [NIKHEF, Amsterdam (Netherlands); Visschers, J.L. [NIKHEF, Amsterdam (Netherlands); Schmitz, J. [University of Twente/MESA (Netherlands)

2006-05-01

A small TPC has been read out by means of a Medipix2 chip as direct anode. A Micromegas foil was placed 50{mu}m above the chip, and electron multiplication occurred in the gap. With a He/isobutane 80/20 mixture, gas multiplication factors up to tens of thousands were achieved, resulting in an efficiency for detecting single electrons of better than 90%. With this new readout technology for gas-filled detectors we recorded many image frames containing 2D images with tracks from cosmic muons. Along these tracks, electron clusters were observed, as well as {delta}-rays. With a gas layer thickness of only 1mm, the device could be applied as vertex detector, outperforming all Si-based detectors.

GOSSIP: A vertex detector combining a thin gas layer as signal generator with a CMOS readout pixel array

International Nuclear Information System (INIS)

Campbell, M.; Heijne, E.H.M.; Llopart, X.; Colas, P.; Giganon, A.; Giomataris, Y.; Chefdeville, M.; Colijn, A.P.; Fornaini, A.; Graaf, H. van der; Kluit, P.; Timmermans, J.; Visschers, J.L.; Schmitz, J.

2006-01-01

A small TPC has been read out by means of a Medipix2 chip as direct anode. A Micromegas foil was placed 50μm above the chip, and electron multiplication occurred in the gap. With a He/isobutane 80/20 mixture, gas multiplication factors up to tens of thousands were achieved, resulting in an efficiency for detecting single electrons of better than 90%. With this new readout technology for gas-filled detectors we recorded many image frames containing 2D images with tracks from cosmic muons. Along these tracks, electron clusters were observed, as well as δ-rays. With a gas layer thickness of only 1mm, the device could be applied as vertex detector, outperforming all Si-based detectors

GOSSIP: A vertex detector combining a thin gas layer as signal generator with a CMOS readout pixel array

Science.gov (United States)

Campbell, M.; Heijne, E. H. M.; Llopart, X.; Colas, P.; Giganon, A.; Giomataris, Y.; Chefdeville, M.; Colijn, A. P.; Fornaini, A.; van der Graaf, H.; Kluit, P.; Timmermans, J.; Visschers, J. L.; Schmitz, J.

2006-05-01

A small TPC has been read out by means of a Medipix2 chip as direct anode. A Micromegas foil was placed 50 μm above the chip, and electron multiplication occurred in the gap. With a He/isobutane 80/20 mixture, gas multiplication factors up to tens of thousands were achieved, resulting in an efficiency for detecting single electrons of better than 90%. With this new readout technology for gas-filled detectors we recorded many image frames containing 2D images with tracks from cosmic muons. Along these tracks, electron clusters were observed, as well as δ-rays. With a gas layer thickness of only 1 mm, the device could be applied as vertex detector, outperforming all Si-based detectors.

Dedicated supernova detection by a network of neutral current spherical TPC detectors

International Nuclear Information System (INIS)

Vergados, J. D.; Giomataris, Y.

2007-01-01

Supernova neutrinos can easily be detected by a spherical gaseous TPC detector measuring very low energy nuclear recoils. The expected rates are quite large for a neutron-rich target since the neutrino-nucleus neutral current interaction yields a coherent contribution of all neutrons. As a matter of fact, for a typical supernova at 10 kpc, about 1000 events are expected using a spherical detector of radius 4 m with Xe gas at a pressure of 10 atm. A worldwide network of several such simple, stable, and low-cost supernova detectors with a running time of a few centuries is quite feasible

Measurement of 1.7–74 MeV polarised γ rays with the HARPO TPC

Energy Technology Data Exchange (ETDEWEB)

Geerebaert, Y., E-mail: yannick.geerebaert@polytechnique.fr [LLR, École Polytechnique, CNRS/IN2P3, Palaiseau (France); Gros, Ph., E-mail: philippe.gros@llr.in2p3.fr [LLR, École Polytechnique, CNRS/IN2P3, Palaiseau (France); Amano, S. [LASTI, University of Hyôgo (Japan); Attié, D. [CEA, Irfu, CEA-Saclay (France); Bernard, D.; Bruel, P. [LLR, École Polytechnique, CNRS/IN2P3, Palaiseau (France); Calvet, D.; Colas, P. [CEA, Irfu, CEA-Saclay (France); Daté, S. [JASRI/SPring8 (Japan); Delbart, A. [CEA, Irfu, CEA-Saclay (France); Frotin, M.; Giebels, B. [LLR, École Polytechnique, CNRS/IN2P3, Palaiseau (France); Götz, D. [AIM, CEA/DSM-CNRS – Université Paris Diderot (France); IRFU/Service d' Astrophysique, CEA-Saclay (France); Hashimoto, S. [LASTI, University of Hyôgo (Japan); Horan, D. [LLR, École Polytechnique, CNRS/IN2P3, Palaiseau (France); Kotaka, T. [LASTI, University of Hyôgo (Japan); Louzir, M. [LLR, École Polytechnique, CNRS/IN2P3, Palaiseau (France); Minamiyama, Y.; Miyamoto, S. [LASTI, University of Hyôgo (Japan); Ohkuma, H. [JASRI/SPring8 (Japan); and others

2017-02-11

Current γ-ray telescopes based on photon conversions to electron-positron pairs, such as Fermi, use tungsten converters. They suffer of limited angular resolution at low energies, and their sensitivity drops below 1 GeV. The low multiple scattering in a gaseous detector gives access to higher angular resolution in the MeV–GeV range, and to the linear polarisation of the photons through the azimuthal angle of the electron-positron pair. HARPO is an R&D programme to characterise the operation of a TPC (Time Projection Chamber) as a high angular-resolution and sensitivity telescope and polarimeter for γ rays from cosmic sources. It represents a first step towards a future space instrument. A 30 cm cubic TPC demonstrator was built, and filled with 2 bar argon-based gas. It was put in a polarised γ-ray beam at the NewSUBARU accelerator in Japan in November 2014. Data were taken at different photon energies from 1.7 MeV to 74 MeV, and with different polarisation configurations. The electronics setup is described, with an emphasis on the trigger system. The event reconstruction algorithm is quickly described, and preliminary measurements of the polarisation of 11 MeV photons are shown.

X-ray detection with Micromegas with background levels below 10$^{-6}$ keV$^{-1}$cm$^{-2}$s$^{-1}$

CERN Document Server

Aune, S; Calvet, D.; Dafni, T.; Diago, A.; Druillole, F.; Fanourakis, G.; Ferrer-Ribas, E.; Galán, J.; García, J.A.; Gardikiotis, A.; Garza, J.G.; Geralis, T.; Giomataris, I.; Gómez, H.; González-Díaz, D.; Herrera, D.C.; Iguaz, F.J.; Irastorza, I.G.; Jourde, D.; Luzón, G.; Mirallas, H.; Mols, J.P.; Papaevangelou, T.; Rodríguez, A.; Seguí, L.; Tomás, A.; Vafeiadis, T.; Yildiz, S.C.

2013-01-01

Micromegas detectors are an optimum technological choice for the detection of low energy x-rays. The low background techniques applied to these detectors yielded remarkable background reductions over the years, being the CAST experiment beneficiary of these developments. In this document we report on the latest upgrades towards further background reductions and better understanding of the detectors' response. The upgrades encompass the readout electronics, a new detector design and the implementation of a more efficient cosmic muon veto system. Background levels below 10$^{-6}$keV$^{-1}$cm$^{-2}$s$^{-1}$ have been obtained at sea level for the first time, demonstrating the feasibility of the expectations posed by IAXO, the next generation axion helioscope. Some results obtained with a set of measurements conducted in the x-ray beam of the CAST Detector Laboratory will be also presented and discussed.

Electron Attenuation Measurement using Cosmic Ray Muons at the MicroBooNE LArTPC

Energy Technology Data Exchange (ETDEWEB)

Meddage, Varuna [Kansas State U., Manhattan

2017-10-01

The MicroBooNE experiment at Fermilab uses liquid argon time projection chamber (LArTPC) technology to study neutrino interactions in argon. A fundamental requirement for LArTPCs is to achieve and maintain a low level of electronegative contaminants in the liquid to minimize the capture of drifting ionization electrons. The attenuation time for the drifting electrons should be long compared to the maximum drift time, so that the signals from particle tracks that generate ionization electrons with long drift paths can be detected efficiently. In this talk we present MicroBooNE measurement of electron attenuation using cosmic ray muons. The result yields a minimum electron 1/e lifetime of 18 ms under typical operating conditions, which is long compared to the maximum drift time of 2.3 ms.

{sup 11}C- and {sup 18}F Production at TPC RK2 Laboratory

Energy Technology Data Exchange (ETDEWEB)

Solin, O.; Johansson, S.; Eriksson, P-O.; Rajander, J.; Kokkomäki, E.; Helin, S.; Arponen, E.; Aromaa, J.; Savisto, N.; Bergman, J.; Heselius, S-J. [Turku PET Centre, Radiopharmaceutical Chemistry Laboratory and Accelerator Laboratory, Porthaninkatu 3, 20500 Turku (Finland)

2009-07-01

Four gas targets for production of [{sup 11}C]CO{sub 2} and [{sup 11}C]CH{sub 4} as well as static and one circulating water target for [{sup 18}F]fluoride production have been installed on the external beam line of the CC18/9 cyclotron (Efremov Institute for Electrophysical Apparatuses, St. Petersburg, Russia) at TPC. The cyclotron is capable of accelerating 18 MeV protons (9 MeV deuterons) at particle beam intensities in excess of 100 μA. The aim with these radionuclide production systems is high yield, high specific radioactivity precursor production for PET radiopharmaceuticals.

Search for anomalies in the neutrino sector with muon spectrometers and large LArTPC imaging detectors at CERN

CERN Document Server

Antonello, A.; Baibussinov, B.; Bilokon, H.; Boffelli, F.; Bonesini, M.; Calligarich, E.; Canci, N.; Centro, S.; Cesana, A.; Cieslik, K.; Cline, D.B.; Cocco, A.G.; Dequal, D.; Dermenev, A.; Dolfini, R.; De Gerone, M.; Dussoni, S.; Farnese, C.; Fava, A.; Ferrari, A.; Fiorillo, G.; Garvey, G.T.; Gatti, F.; Gibin, D.; Gninenko, S.; Guber, F.; Guglielmi, A.; Haranczyk, M.; Holeczek, J.; Ivashkin, A.; Kirsanov, M.; Kisiel, J.; Kochanek, I.; Kurepin, A.; Lagoda, J.; Lucchini, G.; Louis, W.C.; Mania, S.; Mannocchi, G.; Marchini, S.; Matveev, V.; Menegolli, A.; Meng, G.; Mills, G.B.; Montanari, C.; Nicoletto, M.; Otwinowski, S.; Palczewki, T.J.; Passardi, G.; Perfetto, F.; Picchi, P.; Pietropaolo, F.; Plonski, P.; Rappoldi, A.; Raselli, G.L.; Rossella, M.; Rubbia, C.; Sala, P.; Scaramelli, A.; Segreto, E.; Stefan, D.; Stepaniak, J.; Sulej, R.; Suvorova, O.; Terrani, M.; Tlisov, D.; Van de Water, R.G.; Trinchero, G.; Turcato, M.; Varanini, F.; Ventura, S.; Vignoli, C.; Wang, H.G.; Yang, X.; Zani, A.; Zaremba, K; Benettoni, M.; Bernardini, P.; Bertolin, A.; Brugnera, R.; Calabrese, M.; Cecchetti, A.; Cecchini, S.; Collazuol, G.; Creti, P.; Corso, F.Dal; Del Prete, A.; De Mitri, I.; De Robertis, G.; De Serio, M.; Esposti, L.Degli; Di Ferdinando, D.; Dore, U.; Dusini, S.; Fabbricatore, P.; Fanin, C.; Fini, R.A.; Fiore, G.; Garfagnini, A.; Giacomelli, G.; Giacomelli, R.; Guandalini, C.; Guerzoni, M.; Kose, U.; Laurenti, G.; Laveder, M.; Lippi, I.; Loddo, F.; Longhin, A.; Loverre, P.; Mancarella, G.; Mandrioli, G.; Margiotta, A.; Marsella, G.; Mauri, N.; Medinaceli, E.; Mengucci, A.; Mezzetto, M.; Michinelli, R.; Muciaccia, M.T.; Orecchini, D.; Paoloni, A.; Papadia, G.; Pastore, A.; Patrizii, L.; Pozzato, M.; Rosa, G.; Sahnounm, Z.; Simone, S.; Sioli, M.; Sirri, G.; Spurio, M.; Stanco, L.; Surdo, A.; Tenti, M.; Togo, V.; Ventura, M.; Zago, M.

2012-01-01

A new experiment with an intense ~2 GeV neutrino beam at CERN SPS is proposed in order to definitely clarify the possible existence of additional neutrino states, as pointed out by neutrino calibration source experiments, reactor and accelerator experiments and measure the corresponding oscillation parameters. The experiment is based on two identical LAr-TPCs complemented by magnetized spectrometers detecting electron and muon neutrino events at Far and Near positions, 1600 m and 300 m from the proton target, respectively. The ICARUS T600 detector, the largest LAr-TPC ever built with a size of about 600 ton of imaging mass, now running in the LNGS underground laboratory, will be moved at the CERN Far position. An additional 1/4 of the T600 detector (T150) will be constructed and located in the Near position. Two large area spectrometers will be placed downstream of the two LAr-TPC detectors to perform charge identification and muon momentum measurements from sub-GeV to several GeV energy range, greatly comple...

Operation of a LAr-TPC equipped with a multilayer LEM charge readout

Science.gov (United States)

Baibussinov, B.; Centro, S.; Farnese, C.; Fava, A.; Gibin, D.; Guglielmi, A.; Meng, G.; Pietropaolo, F.; Varanini, F.; Ventura, S.; Zatrimaylov, K.

2018-03-01

A novel detector for ionization signals in a single phase LAr-TPC has been experimented in the ICARINO test facility at the INFN Laboratories in Legnaro. It is based on the adoption of a multilayer Large Electron Multiplier (LEM) replacing the traditional anodic wire arrays. Cosmic muon tracks were detected allowing the measurement of energy deposition and a first determination of the signal to noise ratio. The analysis of the recorded events demonstrated the 3D reconstruction capability of this device for ionizing events in liquid Argon. The collected fraction of ionization charge is close to about 90%, with signal to noise ratio similar to that measured with more traditional wire chambers.

arXiv Particle identification studies with a full-size 4-GEM prototype for the ALICE TPC upgrade

CERN Document Server

INSPIRE-00180720; Aiola, S.; Alme, J.; Alt, T.; Amend, W.; Andronic, A.; Anguelov, V.; Appelshäuser, H.; Arslandok, M.; Averbeck, R.; Ball, M.; Barnaföldi, G.G.; Bartsch, E.; Bellwied, R.; Bencedi, G.; Berger, M.; Bialas, N.; Bialas, P.; Bianchi, L.; Biswas, S.; Boldizsár, L.; Bratrud, L.; Braun-Munzinger, P.; Bregant, M.; Britton, C.L.; Brucken, E.J.; Caines, H.; Castro, A.J.; Chattopadhyay, S.; Christiansen, P.; Clonts, L.G.; Cormier, T.M.; Das, S.; Dash, S.; Deisting, A.; Dittrich, S.; Dubey, A.K.; Ehlers, R.; Erhardt, F.; Ezell, N.B.; Fabbietti, L.; Frankenfeld, U.; Gaardhøje, J.J.; Garabatos, C.; Gasik, P.; Gera, A.; Ghosh, P.; Ghosh, S.K.; Glässel, P.; Grachov, O.; Grein, A.; Gunji, T.; Hamagaki, H.; Hamar, G.; Harris, J.W.; Hehner, J.; Hellbär, E.; Helstrup, H.; Hilden, T.E.; Hohlweger, B.; Ivanov, M.; Jung, M.; Just, D.; Kangasaho, E.; Keidel, R.; Ketzer, B.; Khan, S.A.; Kirsch, S.; Klemenz, T.; Klewin, S.; Knospe, A.G.; Kowalski, M.; Kumar, L.; Lang, R.; Langoy, R.; Lautner, L.; Liebske, F.; Lien, J.; Lippmann, C.; Ljunggren, H.M.; Llope, W.J.; Mahmood, S.; Mahmoud, T.; Majka, R.; Malzacher, P.; Marín, A.; Markert, C.; Masciocchi, S.; Mathis, A.; Matyja, A.; Meres, M.; Mihaylov, D.L.; Miskowiec, D.; Mitra, J.; Mittelstaedt, T.; Morhardt, T.; Mulligan, J.; Munzer, R.H.; Münning, K.; Munhoz, M.G.; Muhuri, S.; Murakami, H.; Nandi, B.K.; Natal da Luz, H.; Nattrass, C.; Nayak, T.K.; Negrao De Oliveira, R.A.; Nicassio, M.; Nielsen, B.S.; Oláh, L.; Oskarsson, A.; Otwinowski, J.; Oyama, K.; Paić, G.; Patra, R.N.; Peskov, V.; Pikna, M.; Pinsky, L.; Planinic, M.; Poghosyan, M.G.; Poljak, N.; Pompei, F.; Prasad, S.K.; Pruneau, C.A.; Putschke, J.; Raha, S.; Rak, J.; Rasson, J.; Ratza, V.; Read, K.F.; Rehman, A.; Renfordt, R.; Richert, T.; Røed, K.; Röhrich, D.; Rudzki, T.; Sahoo, R.; Sahoo, S.; Sahu, P.K.; Saini, J.; Schaefer, B.; Schambach, J.; Scheid, S.; Schmidt, C.; Schmidt, H.R.; V Schmidt, N.; Schulte, H.; Schweda, K.; Selyuzhenkov, I.; Sharma, N.; Silvermyr, D.; Singaraju, R.N.; Sitar, B.; Smirnov, N.; Sorensen, S.P.; Sozzi, F.; Stachel, J.; Stenlund, E.; Strmen, P.; Szarka, I.; Tambave, G.; Terasaki, K.; Timmins, A.; Ullaland, K.; Utrobicic, A.; Varga, D.; Varma, R.; Velure, A.; Vislavicius, V.; Voloshin, S.; Voss, B.; Vranic, D.; Wiechula, J.; Winkler, S.; Wikne, J.; Windelband, B.; Zhao, C.

A large Time Projection Chamber is the main device for tracking and charged-particle identification in the ALICE experiment at the CERN LHC. After the second long shutdown in 2019/20, the LHC will deliver Pb beams colliding at an interaction rate of about 50 kHz, which is about a factor of 50 above the present readout rate of the TPC. This will result in a significant improvement on the sensitivity to rare probes that are considered key observables to characterize the QCD matter created in such collisions. In order to make full use of this luminosity, the currently used gated Multi-Wire Proportional Chambers will be replaced. The upgrade relies on continuously operated readout detectors employing Gas Electron Multiplier technology to retain the performance in terms of particle identification via the measurement of the specific energy loss by ionization d$E$/d$x$. A full-size readout chamber prototype was assembled in 2014 featuring a stack of four GEM foils as an amplification stage. The performance of the pr...

micrOMEGAs 2.0.7: a program to calculate the relic density of dark matter in a generic model

Science.gov (United States)

Bélanger, G.; Boudjema, F.; Pukhov, A.; Semenov, A.

2007-12-01

micrOMEGAs2.0.7 is a code which calculates the relic density of a stable massive particle in an arbitrary model. The underlying assumption is that there is a conservation law like R-parity in supersymmetry which guarantees the stability of the lightest odd particle. The new physics model must be incorporated in the notation of CalcHEP, a package for the automatic generation of squared matrix elements. Once this is done, all annihilation and coannihilation channels are included automatically in any model. Cross-sections at v=0, relevant for indirect detection of dark matter, are also computed automatically. The package includes three sample models: the minimal supersymmetric standard model (MSSM), the MSSM with complex phases and the NMSSM. Extension to other models, including non supersymmetric models, is described. Program summaryTitle of program:micrOMEGAs2.0.7 Catalogue identifier:ADQR_v2_1 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADQR_v2_1.html Program obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland Licensing provisions:Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.:216 529 No. of bytes in distributed program, including test data, etc.:1 848 816 Distribution format:tar.gz Programming language used:C and Fortran Computer:PC, Alpha, Mac, Sun Operating system:UNIX (Linux, OSF1, SunOS, Darwin, Cygwin) RAM:17 MB depending on the number of processes required Classification:1.9, 11.6 Catalogue identifier of previous version:ADQR_v2_0 Journal version of previous version:Comput. Phys. Comm. 176 (2007) 367 Does the new version supersede the previous version?:Yes Nature of problem:Calculation of the relic density of the lightest stable particle in a generic new model of particle physics. Solution method:In numerically solving the evolution equation for the density of dark matter, relativistic formulae for the thermal average are used. All tree

Development and test of the DAQ system for a Micromegas prototype installed into the ATLAS experiment

CERN Document Server

Zibell, Andre; The ATLAS collaboration; Bianco, Michele; Martoiu, Victor Sorin

2015-01-01

A Micromegas (MM) quadruplet prototype with an active area of 0.5 m$^2$ that adopts the general design foreseen for the upgrade of the innermost forward muon tracking systems (Small Wheels) of the ATLAS detector in 2018-2019, has been built at CERN and is going to be tested in the ATLAS cavern environment during the LHC RUN-II period 2015-2017. The integration of this prototype detector into the ATLAS data acquisition system using custom ATCA equipment is presented. An ATLAS compatible ReadOutDriver (ROD) based on the Scalable Readout System (SRS), the Scalable Readout Unit (SRU), will be used in order to transmit the data after generating valid event fragments to the high-level Read Out System (ROS). The SRU will be synchronized with the LHC bunch crossing clock (40.08 MHz) and will receive the Level-1 trigger signals from the Central Trigger Processor (CTP) through the TTCrx receiver ASIC. The configuration of the system will be driven directly from the ATLAS Run Control System. By using the ATLAS TDAQ Soft...

Solar Axion search with Micromegas detectors in the CAST Experiment with $^{3}$He as buffer gas

CERN Document Server

García, Juan Antonio

2015-01-01

Axions are well motivated particles proposed in an extension of the Standard Model (SM) as a solution to the CP problem in strong interactions. On the other hand, there is the category of axion-like particles (ALPs) which appear in diverse extensions of the SM and share the same phenomenology of the axion. Axions and ALPs are hypothetical neutral particles that interact weakly with matter, being candidates to solve the Dark Matter problem. CAST, the CERN Axion Solar Telescope is looking for solar axions since 2003. CAST exploit the helioscope technique using a decommissioned LHC dipole magnet in which solar axions could be reconverted into photons. The magnet is mounted on a movable platform that allows tracking the Sun $\\sim$1.5 hours during sunset and during sunrise. The axion signal would be an excess of X-rays in the detectors located at the magnet bore ends and thus low background detectors are mandatory. Three of the four detectors operating at CAST are of the Micromegas type. The analysis of the data o...

Process to process communication over Fastbus in the data acquisition system of the ALEPH TPC

International Nuclear Information System (INIS)

Lusiani, A.

1994-01-01

The data acquisition system of the ALEPH TPC includes a VAX/VMS computer cluster and 36 intelligent Fastbus modules (ALEPH TPPS) running the OS9 multitasking real-time operating system. Dedicated software has been written in order to reliably exchange information over Fastbus between the VAX/VMS cluster and the 36 TPPs to initialize and co-ordinate the microprocessors, and to monitor and debug their operation. The functionality and the performance of this software will be presented together with an overview of the application that rely on it

New read-out electronics for ICARUS-T600 liquid Argon TPC. Description, simulation and tests of the new front-end and ADC system arXiv

CERN Document Server

Bagby, L.; Bellini, V.; Bonesini, M.; Braggiotti, A.; Castellani, L.; Centro, S.; Cervi, T.; Cocco, A.G.; Fabris, F.; Falcone, A.; Farnese, C.; Fava, A.; Fichera, F.; Franciotti, D.; Galet, G.; Gibin, D.; Guglielmi, A.; Guida, R.; Ketchum, W.; Marchini, S.; Menegolli, A.; Meng, G.; Menon, G.; Montanari, C.; Nessi, M.; Nicoletto, M.; Pedrotta, R.; Picchi, P.; Pietropaolo, F.; Rampazzo, G.; Rappoldi, A.; Raselli, G.L.; Rossella, M.; Rubbia, C.; Scaramelli, A.; Sergiampietri, F.; Spanu, M.; Torti, M.; Tortorici, F.; Varanini, F.; Ventura, S.; Vignoli, C.; Zani, A.; Zatti, P.G.

The ICARUS T600, a liquid argon time projection chamber (LAr-TPC) detector mainly devoted to neutrino physics, underwent a major overhauling at CERN in 2016-2017, which included also a new design of the read-out electronics, in view of its operation in Fermilab on the Short Baseline Neutrino (SBN) beam from 2019. The new more compact electronics showed capability of handling more efficiently the signals also in the intermediate Induction 2 wire plane with a significant increase of signal to noise (S/N), allowing for charge measurement also in this view. The new front-end and the analog to digital conversion (ADC) system are presented together with the results of the tests on 50 liters liquid argon TPC performed at CERN with cosmic rays.

Design of the cryogenic systems for the Near and Far LAr-TPC detectors of the Short-Baseline Neutrino program (SBN) at Fermilab

CERN Document Server

Geynisman, M; Chalifour, M; Delaney, M; Dinnon, M; Doubnik, R; Hentschel, S; Kim, M J; Montanari, C; Montanari, D; Nichols, T; Norris, B; Sarychev, M; Schwartz, F; Tillman, J; Zuckerbrot, M

2017-01-01

The Short-Baseline Neutrino (SBN) physics program at Fermilab and Neutrino Platform (NP) at CERN are part of the international Neutrino Program leading to the development of Long-Baseline Neutrino Facility/Deep Underground Neutrino Experiment (LBNF/DUNE) science project. The SBN program consisting of three Liquid Argon Time Projection Chamber (LAr-TPC) detectors positioned along the Booster Neutrino Beam (BNB) at Fermilab includes an existing detector known as MicroBooNE (170-ton LAr-TPC) plus two new experiments known as SBN’s Near Detector (SBND, ~260 tons) and SBN’s Far Detector (SBN-FD, ~760 tons). All three detectors have distinctly different design of their cryostats thus defining specific requirements for the cryogenic systems. Fermilab has already built two new facilities to house SBND and SBN-FD detectors. The cryogenic systems for these detectors are in various stages of design and construction with CERN and Fermilab being responsible for delivery of specific sub-systems. This contribution prese...

LBNO-DEMO (WA105): a large demonstrator of the Liquid Argon double phase TPC

CERN Document Server

Trzaska, Wladyslaw Henryk

2015-01-01

LBNO-DEMO (WA105) is a large demonstrator of the double phase liquid argon TPC intended to develop and test the main elements of the GLACIER-based design for the purpose of scaling it up to the 10–50 kton size needed for Long Baseline Neutrino Oscillation studies. The crucial components of the design are: ultra-high argon purity in non-evacuable tank, long drifts, very high drift voltages, large area Micro Pattern Gas Detectors, and cold preamplifiers. The active volume of the demonstrator is 666 m3 (approximately 300t). WA105 is under construction at CERN and will be exposed to charged particle beams (0.5-20 GeV/c) in the North Area in 2018. The data will provide the necessary calibration of the detector performance and benchmark reconstruction algorithms. This project is a crucial milestone for the long baseline neutrino program, including projects like LBNO and DUNE.

Quality assurance of GEM foils in the framework of the TPC upgrade in the ALICE experiment

CERN Document Server

Ozcelik, Melih Arslan

2016-01-01

In the framework of the TPC upgrade of the ALICE Experiment, new readout chambers will be installed during the LHC long shutdown 2, which is scheduled to start in July 2018. The current MWPCs (Multi Wire Proportional Chambers) will be replaced by readout chambers consisting of GEM (Gas Electron Multipliers) foils in order to meet the increasing readout rate requirements. QA (Quality Assurance) tests on the GEMs are performed to classify the foils. In this report we present the work done during the CERN Summer Student Programme 2016.

MSD与TPC技术调频遥测方法研究%Research on PCM-FM Technology Based on MSD and TPC

Institute of Scientific and Technical Information of China (English)

闫冬; 孙晓锋; 孙大元

2016-01-01

调频信号具有很好的抗航天器飞行尾焰干扰能力。在同信噪比下，调频信号解调误码率高于调相信号，所以调频信号解调需要提高增益。多符号检测（ MSD）和Turbo乘积（ TPC）编码的联合算法可以提高调频信号的增益。介绍了MSD和TPC编码的联合算法和设计结构，根据仿真结果对比了差分解调、 MSD解调、 MSD与TPC编码的联合算法在各种信噪比下的性能指标，证明了该联合算法提高了近7 dB的增益。%The PCM⁃FM signal has better anti⁃interference capability for aerospace⁃craft jetting out the flame.In the same signal⁃noise ratio,the BER of PCM⁃FM signal demodulation is higher than that of phase modulated signal,so it is required to improve the gain of PCM⁃FM signal demodulation.The joint algorithm of multi⁃signal detection (MSD) and Turbo product coding (TPC) can improve the gain of PCM⁃FM signal.This paper introduces the joint algorithm of MSD and TPC coding and design structure.The performance index of differential demodulation,MSD demodulation,as well as MSD and TPC coding joint algoritm are compared in various signal⁃noise ratios, and the results show this joint algorithm can increase the gain of 7 dB.

Energy calibration of a GEM-TPC with Kr83m

Energy Technology Data Exchange (ETDEWEB)

Schmitz, Roman [Helmholtz-Institut fuer Strahlen- und Kernphysik, Universitaet Bonn (Germany); Collaboration: GEM-TPC-Collaboration

2013-07-01

A Time Projection Chamber (TPC) with Gas Electron Multiplier (GEM) readout has been developed with an inner/outer radius of 5/15 cm and a total drift length of 73 cm. It has been used as an inner tracking upgrade for the FOPI experiment at GSI and is planned as a future upgrade to the CBELSA/TAPS experiment. A radioactive {sup 83m}Kr source has been produced and integrated into the setup in order to perform an accurate channel-wise relative gain calibration and monitor gain stability to achieve optimal dE/dx resolution. Its gaseous form makes it perfectly suitable for this purpose allowing a full coverage of the readout plane and providing a wide energy range of conversion peaks. Also its half-life of 1.83 h allows for normal detector operation after a short flushing period of several hours. Calibration method and measured energy resolution for different gas mixtures which have been compared to simulation results are presented in this talk. Also first results on gain stability and pressure/temperature-dependence are shown.

Development and test of the DAQ system for a Micromegas prototype to be installed in the ATLAS experiment

CERN Document Server

Zibell, Andre; The ATLAS collaboration; Bianco, Michele; Martoiu, Victor Sorin

2015-01-01

A Micromegas (MM) quadruplet prototype with an active area of 0.5 m 2 that adopts the general design foreseen for the upgrade of the innermost forward muon tracking systems (Small Wheels) of the ATLAS detector in 2018-2019, has been built at CERN and is going to be tested in the ATLAS cavern environment during the LHC RUN-II period 2015-2017. The integration of this prototype detector into the ATLAS data acquisition system using custom ATCA equipment is presented. An ATLAS compatible Read Out Driver (ROD) based on the Scalable Readout System (SRS), the Scalable Readout Unit (SRU), will be used in order to transmit the data after generating valid event fragments to the high-level Read Out System (ROS). The SRU will be synchronized with the LHC bunch crossing clock (40.08 MHz) and will receive the Level-1 trigger signals from the Central Trigger Processor (CTP) through the TTCrx receiver ASIC. The configuration of the system will be driven directly from the ATLAS Run Control System. By using the ATLAS TDAQ Soft...

Ageing Studies on the First Resistive-MicroMeGaS Quadruplet at GIF++ Preliminary Results

Directory of Open Access Journals (Sweden)

Alvarez Gonzalez B.

2018-01-01

Full Text Available A resistive-MicroMeGaS quadruplet built at CERN has been installed at the new CERN Gamma Irradiation Facility (GIF++ with the aim of carrying out a long-term ageing study. Two smaller resistive bulk-MicroMeGaS produced at the CERN PCB workshop have also been installed at GIF++ in order to provide a comparison of the ageing behavior with the MicroMeGaS quadruplet. We give an overview of the ongoing tests at GIF++ in terms of particle rate, integrated charge and spatial resolution of the MicroMeGaS detectors.

Measurements of electron drift and diffusion properties in a large cylindrical drift chamber (TPC) with parallel electric and magnetic fields

International Nuclear Information System (INIS)

Richstein, J.

1986-01-01

This work describes measurements on the drift of electrons in gases, using the TPC90, the prototype of the ALEPH Time Projection Chamber. Tracks which were created by UV-Laser ionization have been drifted over distances of up to 1.3 m in parallel electric and magnetic fields. Electron drift properties have been systematically measured as a function of these, in several gas mixtures. (orig./HSI)

Design of the cryogenic systems for the Near and Far LAr-TPC detectors of the Short-Baseline Neutrino program (SBN) at Fermilab

Energy Technology Data Exchange (ETDEWEB)

Geynisman, M. [Fermilab; Bremer, J. [CERN; Chalifour, M. [CERN; Delaney, M. [Fermilab; Dinnon, M. [Fermilab; Doubnik, R. [Fermilab; Hentschel, S. [Fermilab; Kim, M. J. [Fermilab; Montanari, C. [INFN, Pavia; Monatanari, D. [Fermilab; Nichols, T. [Fermilab; Norris, B. [Fermilab; Sarychev, M. [Fermilab; Schwartz, F. [Fermilab; Tillman, J. [Fermilab; Zuckerbrot, M. [Fermilab

2017-08-31

The Short-Baseline Neutrino (SBN) physics program at Fermilab and Neutrino Platform (NP) at CERN are part of the international Neutrino Program leading to the development of Long-Baseline Neutrino Facility/Deep Underground Neutrino Experiment (LBNF/DUNE) science project. The SBN program consisting of three Liquid Argon Time Projection Chamber (LAr-TPC) detectors positioned along the Booster Neutrino Beam (BNB) at Fermilab includes an existing detector known as MicroBooNE (170-ton LAr-TPC) plus two new experiments known as SBN’s Near Detector (SBND, ~260 tons) and SBN’s Far Detector (SBN-FD, ~760 tons). All three detectors have distinctly different design of their cryostats thus defining specific requirements for the cryogenic systems. Fermilab has already built two new facilities to house SBND and SBN-FD detectors. The cryogenic systems for these detectors are in various stages of design and construction with CERN and Fermilab being responsible for delivery of specific sub-systems. This contribution presents specific design requirements and typical implementation solutions for each sub-system of the SBND and SBN-FD cryogenic systems.

μ-TPC: a future standard instrument for low energy neutron field characterization

International Nuclear Information System (INIS)

Maire, D.; Lebreton, L.; Petit, M.; Billard, J.; Bourrion, O.; Bosson, G.; Guillaudin, O.; Lamblin, J.; Mayet, F.; Medard, J.; Muraz, J.F.; Richer, J.P.; Riffard, Q.; Santos, D.

2013-06-01

In order to measure energy of neutron fields, with energy ranging from 8 keV to 1 MeV, a new primary standard is being developed at the IRSN (Institute for Radioprotection and Nuclear Safety). This project, μ-TPC (Micro Time Projection Chamber), carried out in collaboration with the LPSC (Laboratoire de Physique Subatomique et de Cosmologie), is based on the nucleus recoil detector principle. The instrument will be presented with the associated method to measure the neutron energy. This article will emphasize the proton energy calibration procedure and energy measurements of a neutron field produced at 127 keV on the IRSN facility AMANDE. Finally the COMIMAC device, dedicated to the calibration, will be described. This original device, developed at the LPSC, is able to produce proton and electron beams with an accurate energy ranging from 1 keV to 50 keV. (authors)

A Prototype Combination TPC Cherenkov Detector with GEM Readout for Tracking and Particle Identification and its Potential Use at an Electron Ion Collider

Directory of Open Access Journals (Sweden)

Woody Craig

2018-01-01

Full Text Available A prototype detector is being developed which combines the functions of a Time Projection Chamber for charged particle tracking and a Cherenkov detector for particle identification. The TPC consists of a 10×10×10 cm3 drift volume where the charge is drifted to a 10×10 cm2 triple GEM detector. The charge is measured on a readout plane consisting of 2×10 mm2 chevron pads which provide a spatial resolution ∼ 100 μm per point in the chevron direction along with dE/dx information. The Cherenkov portion of the detector consists of a second 10×10 cm2 triple GEM with a photosensitive CsI photocathode on the top layer. This detector measures Cherenkov light produced in the drift gas of the TPC by high velocity particles which are above threshold. CF4 or CF4 mixtures will be used as the drift gas which are highly transparent to UV light and can provide excellent efficiency for detecting Cherenkov photons. The drift gas is also used as the operating gas for both GEM detectors. The prototype detector has been constructed and is currently being tested in the lab with sources and cosmic rays, and additional tests are planned in the future to study the detector in a test beam.

A Prototype Combination TPC Cherenkov Detector with GEM Readout for Tracking and Particle Identification and its Potential Use at an Electron Ion Collider

Science.gov (United States)

Woody, Craig; Azmoun, Babak; Majka, Richard; Phipps, Michael; Purschke, Martin; Smirnov, Nikolai

2018-02-01

A prototype detector is being developed which combines the functions of a Time Projection Chamber for charged particle tracking and a Cherenkov detector for particle identification. The TPC consists of a 10×10×10 cm3 drift volume where the charge is drifted to a 10×10 cm2 triple GEM detector. The charge is measured on a readout plane consisting of 2×10 mm2 chevron pads which provide a spatial resolution ˜ 100 μm per point in the chevron direction along with dE/dx information. The Cherenkov portion of the detector consists of a second 10×10 cm2 triple GEM with a photosensitive CsI photocathode on the top layer. This detector measures Cherenkov light produced in the drift gas of the TPC by high velocity particles which are above threshold. CF4 or CF4 mixtures will be used as the drift gas which are highly transparent to UV light and can provide excellent efficiency for detecting Cherenkov photons. The drift gas is also used as the operating gas for both GEM detectors. The prototype detector has been constructed and is currently being tested in the lab with sources and cosmic rays, and additional tests are planned in the future to study the detector in a test beam.

Search for QGP signals at AGS with a TPC spectrometer, and comparison of our event generator predictions for plasma model and cascade interactions

International Nuclear Information System (INIS)

Lindenbaum, S.J.; Foley, K.J.; Eiseman, S.E.

1988-01-01

We have developed and successfully tested a TPC Magnetic Spectrometer to search for QGP signals produced by ion beams at AGS. We also developed a cascade and plasma event generator the predictions of which are used to illustrate how our technique can detect possible plasma signals. 4 refs., 6 figs., 1 tab

Characteristics of triple GEM detector for the ALICE TPC upgrade at CERN

International Nuclear Information System (INIS)

Patra, Rajendra Nath; Singaraju, R.N.; Ahammed, Z.; Nayak, T.K.; Viyogi, Y.P.; Biswas, S.

2016-01-01

Gas Electron Multiplier (GEM) detector, introduced by F. Sauliin 1997 and has been widely improved in last two decades for applications to high energy physics experiments and imaging. GEM detectors have several advantages, like good spatial resolution (∼100 μm), high detection efficiency (>98%), high rate handling capability (∼105 Hz/mm"2 ) and reasonable time response (∼5 ns). The unique features of the GEM detector make it suitable for experiments at Large Hadron Collider (LHC) at CERN and FAIR at GSI. With the increase of beam luminosity of LHC for its next phase of running from the year 2020, the ALICE experiment is planning to take data for PbPb collisions at a rate of 50 kHz. The ALICE Time Projection Chamber (TPC) will be upgraded by GEM based read-out to fulfil this future goal. In this report, results of a thorough test in the laboratory using a newly developed online data monitoring system are discussed

Design and Construction of Precision Tooling for Construction of Micromegas Detectors for the ATLAS Small Wheel Upgrade Project in Germany

CERN Document Server

Losel, Philipp Jonathan; The ATLAS collaboration; Schaile, Otto; Hertenberger, Ralf; Biebel, Otmar; Bortfeldt, Jonathan; Flierl, Bernhard Matthias

2016-01-01

Mechanical precision is a key-aspect of the high-rate capable Micromegas detectors for the upgrade of the Small Wheels of the ATLAS muon spectrometer. 32 SM2 quadruplets will be built by four German institutes with cathodes and strip-anodes made of stable honeycomb sandwiches. To achieve a single plane resolution below $100\\mu m$ the deviation from planarity of a single detector plane must not exceed $80\\mu m$ over the whole active area and the global position of the readout strips has to be within $30\\mu m$ for a single readout-plane of 3 PCB's, as well as between all four planes of a quadruplet. Precision tooling is used for the correct positioning of readout PCB's and readout sandwich planes. For quality control of the planarity of the sandwich planes a laser distance sensor combined with a coordinate measurement system has been developed. Deviation from planarity below 10 $\\mu$m can be easily resolved. We will present key features of the challenging construction procedure to achieve this high level of pre...

Construction and QA/QC of the MicroMegas Pavia Readout Panels for the Muon Spectrometer Upgrade of the ATLAS Experiment

CERN Document Server

Kourkoumeli-Charalampidi, Athina; The ATLAS collaboration

2016-01-01

In order to cope with the required precision tracking and trigger capabilities during Run III in ATLAS experiment, the innermost layer of the Muon Spectrometer endcap (Small Wheels) will be upgraded. The New Small Wheel (NSW) will be equipped with eight layers of MicroMegas (MM) detectors and eight layers of small-strip Thin Gap Chambers (sTGC), both arranged in two quadruplets. MM detectors of large size (up to 2 $m^{2}$) will be employed for the first time in HEP experiments. Four different types of MM quadruplets modules (SM1, SM2, LM1, LM2), built by different Institutes, will compose the NSW. Italian INFN is responsible for the construction of the SM1 modules. The construction is shared among different INFN sites. In particular, readout panels are built in Pavia. Due to the challenging mechanical specifications (with precisions of tens microns over meters), the construction procedure has been optimized to obtain the required strip alignment precision in the panel. A number of data quality checks on both ...

Firmware Development and Integration for ALICE TPC and PHOS Front-end Electronics A Trigger Based Readout and Control System operating in a Radiation Environment

CERN Document Server

AUTHOR|(CDS)2068589; Rohrich, Dieter

2008-01-01

The readout electronics in PHOS and TPC - two of the major detectors of the ALICE experiment at the LHC - consist of a set of Front End Cards (FECs) that digitize, process and buffer the data from the detector sensors. The FECs are connected to a Readout Control Unit (RCU) via two sets of custom made PCB backplanes. For PHOS, 28 FECs are connected to one RCU, while for TPC the number is varying from 18 to 25 FECs depending on location. The RCU is in charge of the data readout, including reception and distribution of triggers and in moving the data from the FECs to the Data Acquisition System. In addition it does low level control tasks. The RCU consists of an RCU Motherboard that hosts a Detector Control System (DCS) board and a Source Interface Unit. The DCS board is an embedded computer running Linux that controls the readout electronics. All the mentioned devices are implemented in commercial grade SRAM based Field Programmable Gate Arrays (FPGAs). Even if these devices are not very radiation tolerant, the...

Study of the machine background induced by the PEP-II collider with a mini-TPC. Study of the doubly-charmed decay of the B meson with the detector BaBar

International Nuclear Information System (INIS)

Trincaz-Duvoid, S.

2001-01-01

The work presented in this thesis is divided into two parts. The first one deals with the machine background induced by the PEP-II collider. This study has been performed with a mini-TPC before the start of the BaBar experiment. The second part concerns the measurements of the branching ratio of the decay modes B 0 → D *- D(*) 0 K + and of the inclusive branching ratio Br(B 0 → K ± X). These measurements have been obtained with the first BaBar data. During the commissioning of the PEP-II collider, the charged tracks rate close to the interaction point has been measured with the mini-TPC. This study has pointed to the fact that the machine background was much higher than predicted by the simulation. These bad background conditions were due to the poor quality of the vacuum in the rings. This relatively high pressure in the rings produces electro-magnetic showers at the interaction point due to beam gas interactions. The potential risks for the BaBar detector due to the machine backgrounds have been clearly pointed out by the studies performed for this thesis. The addition of some collimators and a deep understanding of the machine have greatly reduced the background. Nevertheless, the radiation level in BaBar is continuously monitored in order to protect the detector. The study of the b → cc-bar channel is an important point for the understanding of the overall picture of the B meson decay. With an integrated luminosity of 17.3 fb -1 recorded by the BaBar detector the following branching ratio using exclusive reconstruction technique have been measured: Br(B 0 → D *- D 0 K + ) = (0.29 ± 0.06 (stat) ± (syst)) % Br(B 0 → D *- D *0 K + ) = (1.16 ± 0.15 (stat) ± 0.16 (syst)) % A partial reconstruction has also been developed. With an integrated luminosity of 8.9 fb -1 , the branching ratio of B 0 into D *- D 0 K + has been measured: Br(B 0 → D *- D 0 K + ) = (0.45 ± 0.12 (stat) ± 0.25 (syst)) % This result is in good agreement with the value obtained

Developing Light Collection Enhancements and Wire Tensioning Methods for LArTPC Neutrino Detectors

Energy Technology Data Exchange (ETDEWEB)

Spagliardi, Fabio [Univ. of Manchester (United Kingdom)

2017-01-01

Liquid argon Time Projection Chambers (LArTPCs) are becoming widely used as neutrino detectors because of their image-like event reconstruction which enables precision neutrino measurements. They primarily use ionisation charge to reconstruct neutrino events. It has been shown, however, that the scintillation light emitted by liquid argon could be exploited to improve their performance. As the neutrino measurements planned in the near future require large-scale experiments, their construction presents challenges in terms of both charge and light collection. In this dissertation we present solutions developed to improve the performance in both aspects of these detectors. We present a new wire tensioning measurement method that allows a remote measurement of the tension of the large number wires that constitute the TPC anode. We also discuss the development and installation of WLS-compound covered foils for the SBND neutrino detector at Fermilab, which is a technique proposed t o augment light collection in LArTPCs. This included preparing a SBND-like mesh cathode and testing it in the Run III of LArIAT, a test beam detector also located at Fermilab. Finally, we present a study aimed at understanding late scintillation light emitted by recombining positive argon ions using LArIAT data, which could affect large scale surface detectors.

Construction and QA/QC of the Micromegas Pavia Readout Panels for the Muon Spectrometer Upgrade of the ATLAS New Small Wheel

CERN Document Server

Kourkoumeli-Charalampidi, Athina; The ATLAS collaboration

2016-01-01

In order to cope with the required precision tracking and trigger capabilities from Run III onwards in the ATLAS experiment, the innermost layer of the Muon Spectrometer endcap (Small Wheels) will be upgraded. The New Small Wheel (NSW) will be equipped with eight layers of MicroMegas (MM) detectors and eight layers of small-strip Thin Gap Chambers (sTGC), both arranged in two quadruplets. MM detectors of large size (up to 3 m$^2$) will be employed for the first time in HEP experiments. Four different types of MM quadruplets modules (SM1, SM2, LM1, LM2), built by different Institutes, will compose the NSW. The Italian INFN is responsible for the construction of the SM1 modules. The construction is shared among different INFN sites, Pavia being responsible for the readout panel construction. Due to the challenging mechanical specifications (with precisions of tens microns over meters), the construction procedure has been optimized to obtain the required strip alignment precision in the panel. A number of data q...

Electroluminescence pulse shape and electron diffusion in liquid argon measured in a dual-phase TPC

Energy Technology Data Exchange (ETDEWEB)

Agnes, P.; et al.

2018-02-05

We report the measurement of the longitudinal diffusion constant in liquid argon with the DarkSide-50 dual-phase time projection chamber. The measurement is performed at drift electric fields of 100 V/cm, 150 V/cm, and 200 V/cm using high statistics $^{39}$Ar decays from atmospheric argon. We derive an expression to describe the pulse shape of the electroluminescence signal (S2) in dual-phase TPCs. The derived S2 pulse shape is fit to events from the uppermost portion of the TPC in order to characterize the radial dependence of the signal. The results are provided as inputs to the measurement of the longitudinal diffusion constant DL, which we find to be (4.12 $\\pm$ 0.04) cm$^2$/s for a selection of 140keV electron recoil events in 200V/cm drift field and 2.8kV/cm extraction field. To study the systematics of our measurement we examine datasets of varying event energy, field strength, and detector volume yielding a weighted average value for the diffusion constant of (4.09 $\\pm$ 0.09) cm$^2$ /s. The measured longitudinal diffusion constant is observed to have an energy dependence, and within the studied energy range the result is systematically lower than other results in the literature.

Construction and performance of the sTGC and MicroMegas chambers for ATLAS NSW upgrade

Science.gov (United States)

Sekhniaidze, G.

2017-03-01

The innermost stations of the current ATLAS muon end-cap system, the Small Wheels, must be upgraded in 2019 to retain their good precision tracking and trigger capabilities in the high background environment expected with the upcoming luminosity increase of the LHC. The New Small Wheels (NSW) will employ two chamber technologies: eight layers of MicroMegas (MM) arranged in two quadruplets, sandwiched between two quadruplets of small-strip Thin Gap Chambers (sTGC) for a total of about 2400 m2 of detection planes. All quadruplets have trapezoidal shapes with surface areas between 1 and 3 m2. Both MM and sTGC systems will independently provide trigger and tracking capabilities. The readout boards are industrially produced for both technologies and an accurate quality control is needed. In order to achieve a 15% transverse momentum resolution for 1 TeV muons, in addition to an excellent intrinsic resolution (010 μm), the mechanical precision of each plane of the assembled modules must be as good as 30 μm along the precision coordinate and 80 μm perpendicular to the chamber. In 2016 the milestone to build the first module-0 prototypes for both technologies has been reached. The construction procedure of the module-0 detectors will be reviewed, along with the results of the quality control checks performed during construction. The module-0 have been measured and subjected to a thorough validation. Results obtained with high-energy particle beams, with cosmic rays and with X-rays will be presented.

Search for “anomalies” from neutrino and anti-neutrino oscillations at $\\Delta_m^{2} ≈ 1eV^{2}$ with muon spectrometers and large LAr–TPC imaging detectors

CERN Document Server

Antonello, M; Baibussinov, B; Bilokon, H; Boffelli, F; Bonesini, M; Calligarich, E; Canci, N; Centro, S; Cesana, A; Cieslik, K; Cline, D B; Cocco, A G; Dequal, D; Dermenev, A; Dolfini, R; De Gerone, M; Dussoni, S; Farnese, C; Fava, A; Ferrari, A; Fiorillo, G; Garvey, G T; Gatti, F; Gibin, D; Gninenko, S; Guber, F; Guglielmi, A; Haranczyk, M; Holeczek, J; Ivashkin, A; Kirsanov, M; Kisiel, J; Kochanek, I; Kurepin, A; Łagoda, J; Lucchini, G; Louis, W C; Mania, S; Mannocchi, G; Marchini, S; Matveev, V; Menegolli, A; Meng, G; Mills, G B; Montanari, C; Nicoletto, M; Otwinowski, S; Palczewski, T J; Passardi, G; Perfetto, F; Picchi, P; Pietropaolo, F; Płonski, P; Rappoldi, A; Raselli, G L; Rossella, M; Rubbia, C; Sala, P; Scaramelli, A; Segreto, E; Stefan, D; Stepaniak, J; Sulej, R; Suvorova, O; Terrani, M; Tlisov, D; Van de Water, R G; Trinchero, G; Turcato, M; Varanini, F; Ventura, S; Vignoli, C; Wang, H G; Yang, X; Zani, A; Zaremba, K; Benettoni, M; Bernardini, P; Bertolin, A; Bozza, C; Brugnera, R; Cecchetti, A; Cecchini, S; Collazuol, G; Creti, P; Dal Corso, F; De Mitri, I; De Robertis, G; De Serio, M; Degli Esposti, L; Di Ferdinando, D; Dore, U; Dusini, S; Fabbricatore, P; Fanin, C; Fini, R A; Fiore, G; Garfagnini, A; Giacomelli, G; Giacomelli, R; Grella, G; Guandalini, C; Guerzoni, M; Kose, U; Laurenti, G; Laveder, M; Lippi, I; Loddo, F; Longhin, A; Loverre, P; Mancarella, G; Mandrioli, G; Margiotta, A; Marsella, G; Mauri, N; Medinaceli, E; Mengucci, A; Mezzetto, M; Michinelli, R; Muciaccia, M T; Orecchini, D; Paoloni, A; Pastore, A; Patrizii, L; Pozzato, M; Rescigno, R; Rosa, G; Simone, S; Sioli, M; Sirri, G; Spurio, M; Stanco, L; Stellacci, S; Surdo, A; Tenti, M; Togo, V; Ventura, M; Zago, M

2012-01-01

This proposal describes an experimental search for sterile neutrinos beyond the Standard Model with a new CERN-SPS neutrino beam. The experiment is based on two identical LAr-TPC's followed by magnetized spectrometers, observing the electron and muon neutrino events at 1600 and 300 m from the proton target. This project will exploit the ICARUS T600, moved from LNGS to the CERN "Far" position. An additional 1/4 of the T600 detector will be constructed and located in the "Near" position. Two spectrometers will be placed downstream of the two LAr-TPC detectors to greatly complement the physics capabilities. Spectrometers will exploit a classical dipole magnetic field with iron slabs, and a new concept air-magnet, to perform charge identification and muon momentum measurements in a wide energy range over a large transverse area. In the two positions, the radial and energy spectra of the nu_e beam are practically identical. Comparing the two detectors, in absence of oscillations, all cross sections and experimenta...

Effects of different extracts of curcumin on TPC1 papillary thyroid cancer cell line.

Science.gov (United States)

Perna, Angelica; De Luca, Antonio; Adelfi, Laura; Pasquale, Tammaro; Varriale, Bruno; Esposito, Teresa

2018-02-15

The thyroid gland is one of the largest endocrine glands in the body. The vast majority of TCs (> 90%) originate from follicular cells and are defined as differentiated thyroid cancers (DTC) and the two histological subtypes are the papillary TC with its variants and the follicular TC. Curcumin possesses a wide variety of biological functions, and thanks to its properties, it has gained considerable attention due to its profound medicinal values (Prasad, Gupta, Tyagi, and Aggarwal, Biotechnol Adv 32:1053-1064, 2014). We have undertaken the present work in order to define the possible role of curcumin in modulating the genetic expression of cell markers and to understand the effectiveness of this nutraceutical in modulating the regression of cancer phenotype. As a template we used the TPC-1 cells treated with the different extracts of turmeric, and examined the levels of expression of different markers (proliferative, inflammatory, antioxidant, apoptotic). Treatment with the three different curcumin extracts displays anti-inflammatory, antioxidant properties and it is able to influence cell cycle with slightly different effects upon the extracts. Furthermore curcumin is able to influence cell metabolic activity vitality. In conclusion curcumin has the potential to be developed as a safe therapeutic but further studies are needed to verify its antitumor ability in vivo.

A Preliminary Study on Time Projection Chamber Simulation for Fission Cross Section Measurements with Geant4

International Nuclear Information System (INIS)

Kim, Jong Woon; Lee, Youngouk; Kim, Jae Cheon

2014-01-01

We present the details of the TPC simulation with Geant4 and show the results. TPC can provide more information than a fission chamber in that it is possible to distinguish different particle types. Simulations are conducted for uranium and plutonium targets with 20MeV neutrons. The simulation results are compared with the reference and show reasonable results. This is the first phase of study for realizing a TPC in the NFS at RAON, and we have more work to do, such as applying an electric field, signal processing in the simulation, and manufacturing of a TPC. The standard in fission cross section measurement is a fission chamber. It is basically just two parallel plates separated by a few centimeters of gas. A power supply connected to the plates sets up a moderate electric field. The target is deposited onto one of the plates. When fission occurs, the fragments ionize the gas, and the electric field causes the produced electrons to drift to the opposite plate, which records the total energy deposited in the chamber. A Time Projection Chamber (TPC) is a gas ionization detector similar to a fission chamber. However, it can measure the charged particle trajectories in the active volume in three dimensions by adding several readouts on the pad plane (fission chamber has only one readout one a pad plane). The specific ionization for each particle track enables the TPC to distinguish different particle types. A TPC will be used for fission cross section measurements in the Neutron Science Facility (NSF) at RAON. As a preliminary study, we present details of TPC simulation with Geant4 and discuss the results

Development of Advanced Gaseous Detectors for Muon Tracking and Triggering in Collider Experiments

CERN Document Server

Guan, Liang; Zhao, Zhengguo; Zhu, Junjie

High luminosity and high energy collider experiments impose big challenges to conventional gaseous detectors used for muon tracking and triggering. Stringent requirements, in terms of time and spatial resolutions, rate capabilities etc. are expected. In the context of ATLAS muon upgrade project, we present extensive researches and developments of advanced gas detectors for precision muon tracking and triggering in high rate environments. Particularly, this dissertation focuses on the studies of Micro-mesh Gaseous structure (Micromegas), thin gap Resistive Plate Chamber (RPC) and small strip Thin Gap multi-wire Chambers (sTGC). In this dissertation, we first present a novel method, based on thermally bonding micro-meshes to anodes, to construct Micromegas detectors. Without employing the traditional photo-lithography process, it is a convenient alternative to build Micromegas. Both experimental and simulation studies of basic performance parameters of thermo-bonded Micromegas will be reported. Development...

Study on ECH-assisted start-up using trapped particle configuration in KSTAR and application to ITER

Science.gov (United States)

Lee, Jeongwon; Kim, Jayhyun; An, YoungHwa; Yoo, Min-Gu; Hwang, Y. S.; Na, Yong-Su

2017-12-01

ECH-assisted start-up using trapped particle configuration (TPC) is firstly studied in a superconducting, conventional tokamak, KSTAR. First, improved and efficient start-up using TPC than conventional field null configuration (FNC) is achieved by enhanced pre-ionization plasma quality. TPC shows the broader operation window in terms of the poloidal field quality and the deuterium prefill pressure than that of FNC. Surprisingly the particle trapping enhances the plasma start-up performance even with much lower particle trapping ratio than that of spherical torus. Reliability of TPC with low trapping ratio is investigated by 0D plasma evolution code, TECHP0D. Second, the characteristics of TPC start-up are explored with experiments and modellings. Two kind of start-up failure conditions are identified by the magnetic pitch and prefill pressure scan experiments: (i) low ionization rate; and (ii) low density condition. These experimental observation has consistency with TECHP0D modeling result. Finally, reliable ITER-relevant low toroidal electric field start-up using TPC is achieved with drastically improved success rate of start-up in KSTAR. In this experiments, validity of the ITER-like toroidally inclined ECH/ECCD injection is also expected. Time dependent ITER start-up scenario using TPC is proposed and the superiority of it than FNC is discussed.

The $\\mu$TPC Method: Improving the Position Resolution of Neutron Detectors Based on MPGDs

CERN Document Server

Pfeiffer, Dorothea; Birch, Jens; Hall-Wilton, Richard; Höglund, Carina; Hultman, Lars; Iakovidis, George; Oliveri, Eraldo; Oksanen, Esko; Ropelewski, Leszek; Thuiner, Patrik

2015-01-01

Due to the Helium-3 crisis, alternatives to the standard neutron detection techniques are becoming urgent. In addition, the instruments of the European Spallation Source (ESS) require advances in the state of the art of neutron detection. The instruments need detectors with excellent neutron detection efficiency, high-rate capabilities and unprecedented spatial resolution. The Macromolecular Crystallography instrument (NMX) requires a position resolution in the order of 200 um over a wide angular range of incoming neutrons. Solid converters in combination with Micro Pattern Gaseous Detectors (MPGDs) are proposed to meet the new requirements. Charged particles rising from the neutron capture have usually ranges larger than several millimetres in gas. This is apparently in contrast with the requirements for the position resolution. In this paper, we present an analysis technique, new in the field of neutron detection, based on the Time Projection Chamber (TPC) concept. Using a standard Single-GEM with the catho...

For high energy heavy ion experiments TPC 4π detector 'Diogene'. What possibilities and what physics

International Nuclear Information System (INIS)

Babinet, R.; Cassagnou, Y.; Drouet, M.

1981-05-01

'Diogene' is the name of a 4π solid angle detector, based on a Time Projection Chamber (TPC), designed to perform exclusive measurements of charged particles emitted in central collisions of relativistic heavy ions. Exclusive measurements of all charged particles emitted in central collisions of relativistic heavy ions are becoming more and more necessary in this field of nuclear physics in order to answer some crucial questions such as: what is the degree of compression achieved in these collisions. What is the behavior of nuclear matter at high degree of excitation as well as compression. The possibility of handling high multiplicities up to 40 or 60; a momentum measurement of all particles, with not too bad a resolution, up to about 1.5 GeV/c; a good particle identification between π +- , p, d, t ..

Measurement of the 234U(n, f ) cross-section with quasi-monoenergetic beams in the keV and MeV range using a Micromegas detector assembly

Science.gov (United States)

Stamatopoulos, A.; Kanellakopoulos, A.; Kalamara, A.; Diakaki, M.; Tsinganis, A.; Kokkoris, M.; Michalopoulou, V.; Axiotis, M.; Lagoyiannis, A.; Vlastou, R.

2018-01-01

The 234U neutron-induced fission cross-section has been measured at incident neutron energies of 452, 550, 651 keV and 7.5, 8.7, 10 MeV using the 7Li ( p, n) and the 2H( d, n) reactions, respectively, relative to the 235U( n, f ) and 238U( n, f ) reference reactions. The measurement was performed at the neutron beam facility of the National Center for Scientific Research "Demokritos", using a set-up based on Micromegas detectors. The active mass of the actinide samples and the corresponding impurities were determined via α-spectroscopy using a surface barrier silicon detector. The neutron spectra intercepted by the actinide samples have been thoroughly studied by coupling the NeuSDesc and MCNP5 codes, taking into account the energy and angular straggling of the primary ion beams in the neutron source targets in addition to contributions from competing reactions ( e.g. deuteron break-up) and neutron scattering in the surrounding materials. Auxiliary Monte Carlo simulations were performed making combined use of the FLUKA and GEF codes, focusing particularly on the determination of the fission fragment detection efficiency. The developed methodology and the final results are presented.

Studies of field distortions in a time projection chamber for the International Linear Collider

International Nuclear Information System (INIS)

Zenker, Klaus

2014-12-01

The International Linear Collider (ILC) will allow to do precision measurements of Standard Model parameter and to search for new physics. The ILD detector concept, which is developed for the ILC, uses a Time Projection Chamber (TPC) as central tracking device. The momentum resolution goal for the ILD TPC is δ(1/p t ) ≅ 10 -4 (GeV/c) -1 at a magnetic field of B=3.5 T. Field distortions of the magnetic or electric field inside the sensitive volume of the TPC distort the momentum measurements. Therefore, one needs to keep them under control and correct them with high precision. In this thesis the main sources of field distortions in the TPC are identified and their effects are determined. Furthermore, possibilities to reduce the identified field distortions are presented. One known source of distortions of the electric field are ions, produced by the gas amplification in the TPC anode, that drift into the sensitive volume of the TPC. In the first part of this work the creation of these ions in Gas Electron Multiplier (GEM), which are used for the gas amplification, is studied. It will be shown that the resulting field distortions are not acceptable at the ILD TPC. By tuning the parameters of the gas amplification at the anode the field distortion can be reduced, which is shown in measurements and simulations. In addition measurements using a modified GEM show that it is possible to further reduce the field distortions with such a GEM. In the second part of this work field distortions arising at boundaries between individual readout modules are investigated using simulation studies. It will be shown in simulations, which are verified by measurement results, that these field distortions significantly influence the readout module performance. Based on the simulation results the GEM based readout module developed at DESY is optimised and the field distortions are reduced. These performance improvements could also be verified in measurements. Finally, a laser

ArgonCube: a Modular Approach for Liquid Argon TPC Neutrino Detectors for Near Detector Environments

CERN Document Server

Auger, M; Sinclair, JR

2017-01-01

Liquid Argon Time Projection Chambers (LAr TPCs) are an ideal detector candidate for future neutrino oscillation physics experiments, underground neutrino observatories and proton decay searches. A large international project based on this technology is currently under consideration at the future LBNF/DUNE facility in the United States. That particular endeavor would be on the very large mass scale of 40~kt. Following diverse and long standing R\\&D work conducted over several years, with contributions from international collaborators, we propose a novel LAr TPC based on a fully-modular, innovative design, ArgonCube. ArgonCube will demonstrate that LAr TPCs are a viable detector technology for high-energy and high-multiplicity environments, such as the DUNE near detector. Necessary R\\&D work is proceeding along two main pathways; the first, aimed at the demonstration of modular detector design and the second, at the exploration of new signal readout methods. This two-pronged approach has provided a hig...

Search for Solar Axions with the CAST-Experiment

CERN Document Server

Vogel, J.; Aune, S.; Autiero, D.; Barth, K.; Belov, A.; Beltran, B.; Borghi, S.; Bourlis, G.; Boydag, F. S.; Brauninger, H.; Carmona, J.; Cebrian, S.; Cetin, S. A.; Collar, J.I.; Dafni, T.; Davenport, M.; Di Lella, L.; Dogan, O. B.; Elefheriadis, C.; Elias, N.; Fanourakis, G.; Ferrer-Ribas, E.; Fisher, H.; Franz, J.; Galan, J.; Geralis, T.; Giomataris, I.; Gninenko, S.; Gomez, H.; Hasinoff, M.; Heinsius, H.; Hikmet, I.; Hoffmann, D. H. H.; Irastorza, I. G.; Jacoby, J.; Jakovcic, K.; Kang, D.; Konigsmann, K.; Kotthaus, R.; Krcmar, M.; Kousouris, K.; Kuster, M.; Lakic, B.; Lasseur, C.; Liolios, A.; Ljubicic, A.; Lutz, G.; Luzon, G.; Miller, D.; Morales, J.; Niinikoski, T.; Nordt, A.; Ortiz, A.; Papaevangelou, T.; Pivovaroff, M.; Placci, A.; Raffelt, G.; Riege, H.; Rodriguez, A.; Ruz, J.; Savvidis, I.; Semertzidis, Y.; Serpico, P.; Soufli, R.; Stewart, L.; Tzamarias, S.; Van Bibber, K.; Villar, J.; Walckiers, L.; Zioutas, K.; Morales, A.

2008-01-01

Solar axions can be produced in the Sun via the so-called Primakoff effect. The CERN Axion Solar Telescope (CAST) uses an LHC prototype magnet of about 9 T to reconvert these axions into photons. The magnet is able to follow the Sun for about 3 hours per day. Three different X-Ray detectors are mounted on its ends to detect photons from axion-to-photon conversion: a Time Projection Chamber (TPC), a MICROMEGAS (MICROMEsh GAseous Structure) and a Charge Coupled Device (CCD). For the CCD an X-ray focusing device is used to improve the signal-to-background ratio significantly. With the completion of CAST'S first phase, the current limits on the coupling constant gaγ for axion masses up to 0.02 eV have been improved. In its second phase, CAST extends the axion mass range by filling the magnet with a buffer gas. Masses up to about 0.4 eV have already been covered and thus the experiment is entering the regions favored by axion models. This paper will present the status of CAST'S second phase.

High spatial and time resolutions with gas ionization detectors

International Nuclear Information System (INIS)

Pouthas, J.

2001-09-01

This document presents the principles and the characteristics of the gaseous ionisation detectors used in position and timing measurements. The first two parts recall the main notions (electron and ion motions, gaseous amplification, signal formation) and their applications to the proportional counter and the wire chamber. The explanation of the signal formation makes use of the Ramo theorem. The third part is devoted to the different types of wire chambers: drift or cathode strip chambers, TPC (time projection chamber). Some aspects on construction and ageing are also presented. Part 4 is on the detectors in which the multiplication is performed by a 'Parallel Plate' system (PPAC, Pestov counter). Special attention is paid to the RPCs (Resistive Plate Chambers) and their timing resolutions. Part 5 concentrates on 'Micro-pattern detectors' which use different kinds of microstructure for gaseous amplification. The new detectors MICROMEGAS, CAT (compteur a trous) and GEM (gas electron multiplier) and some of their applications are presented. The last part is a bibliography including some comments on the documents. (author)

High spatial and time resolutions with gas ionization detectors; Hautes resolutions en position et temps avec des detecteurs gazeux a ionisation

Energy Technology Data Exchange (ETDEWEB)

Pouthas, J

2001-09-01

This document presents the principles and the characteristics of the gaseous ionisation detectors used in position and timing measurements. The first two parts recall the main notions (electron and ion motions, gaseous amplification, signal formation) and their applications to the proportional counter and the wire chamber. The explanation of the signal formation makes use of the Ramo theorem. The third part is devoted to the different types of wire chambers: drift or cathode strip chambers, TPC (time projection chamber). Some aspects on construction and ageing are also presented. Part 4 is on the detectors in which the multiplication is performed by a 'Parallel Plate' system (PPAC, Pestov counter). Special attention is paid to the RPCs (Resistive Plate Chambers) and their timing resolutions. Part 5 concentrates on 'Micro-pattern detectors' which use different kinds of microstructure for gaseous amplification. The new detectors MICROMEGAS, CAT (compteur a trous) and GEM (gas electron multiplier) and some of their applications are presented. The last part is a bibliography including some comments on the documents. (author)

High-rate irradiation of 15 mm muon drift tubes and development of an ATLAS compatible readout driver for micromegas detectors

Energy Technology Data Exchange (ETDEWEB)

Zibell, Andre

2014-06-06

The upcoming luminosity upgrades of the LHC accelerator at CERN demand several upgrades to the detectors of the ATLAS muon spectrometer, mainly due to the proportionally increasing rate of uncorrelated background irradiation. This concerns also the ''Small Wheel'' tracking stations of the ATLAS muon spectrometer, where precise muon track reconstruction will no longer be assured when around 2020 the LHC luminosity is expected to reach values 2 to 5 times the design luminosity of 1 x 10{sup 34} cm{sup -2}s{sup -1}, and when background hit rates will exceed 10 kHz/cm{sup 2}. This, together with the need of an additional triggering station in this area with an angular resolution of 1 mrad, requires the construction of ''New Small Wheel'' detectors for a complete replacement during the long maintenance period in 2018 and 2019. As possible technology for these New Small Wheels, high-rate capable sMDT drift tubes have been investigated, based on the ATLAS 30 mm Monitored Drift Tube technology, but with a smaller diameter of 15 mm. In this work, a prototype sMDT chamber has been tested under the influence of high-rate irradiation with protons, neutrons and photons at the Munich tandem accelerator, simulating the conditions within a high luminosity LHC experiment. Tracking resolution and detection efficiency for minimum ionizing muons are presented as a function of irradiation rate. The experimental muon trigger geometry allows to distinguish between efficiency degradation due to deadtime effects and space charge in the detectors. Using modified readout electronics the analog pulse shape of the detector has been investigated for gain reduction and potential irregularities due to the high irradiation rates and ionization doses. This study shows that the sMDT detectors would fulfill all requirements for successful use in the ATLAS New Small Wheel endcap detector array, with an average spatial resolution of 140 μm and a track

High-rate irradiation of 15 mm muon drift tubes and development of an ATLAS compatible readout driver for micromegas detectors

International Nuclear Information System (INIS)

Zibell, Andre

2014-01-01

The upcoming luminosity upgrades of the LHC accelerator at CERN demand several upgrades to the detectors of the ATLAS muon spectrometer, mainly due to the proportionally increasing rate of uncorrelated background irradiation. This concerns also the ''Small Wheel'' tracking stations of the ATLAS muon spectrometer, where precise muon track reconstruction will no longer be assured when around 2020 the LHC luminosity is expected to reach values 2 to 5 times the design luminosity of 1 x 10 34 cm -2 s -1 , and when background hit rates will exceed 10 kHz/cm 2 . This, together with the need of an additional triggering station in this area with an angular resolution of 1 mrad, requires the construction of ''New Small Wheel'' detectors for a complete replacement during the long maintenance period in 2018 and 2019. As possible technology for these New Small Wheels, high-rate capable sMDT drift tubes have been investigated, based on the ATLAS 30 mm Monitored Drift Tube technology, but with a smaller diameter of 15 mm. In this work, a prototype sMDT chamber has been tested under the influence of high-rate irradiation with protons, neutrons and photons at the Munich tandem accelerator, simulating the conditions within a high luminosity LHC experiment. Tracking resolution and detection efficiency for minimum ionizing muons are presented as a function of irradiation rate. The experimental muon trigger geometry allows to distinguish between efficiency degradation due to deadtime effects and space charge in the detectors. Using modified readout electronics the analog pulse shape of the detector has been investigated for gain reduction and potential irregularities due to the high irradiation rates and ionization doses. This study shows that the sMDT detectors would fulfill all requirements for successful use in the ATLAS New Small Wheel endcap detector array, with an average spatial resolution of 140 μm and a track reconstruction efficiency

Direct Dark Matter Detection through the use of a Xenon Based TPC Detector

Science.gov (United States)

Daniel, Jonathan; Akerib, Daniel; LZ group at SLAC

2018-01-01

The vast majority of matter in the universe is unaccounted for. Only 15% of the universe's mass density is visible matter, while the other 85% is Dark Matter (DM). The Weakly Interacting Massive Particle (WIMP) is currently the frontrunner of the DM candidates. The Large Underground Xenon (LUX) and next generation LUX-ZEPLIN (LZ) experiments are designed to directly detect WIMPs. Both experiments are xenon-based Time Projection Chambers (TPC) used to observe possible WIMP interactions. These interactions produce photons and electrons with the photons being collected in a set of two photomultiplier tube (PMT) arrays and the electrons drifted upwards in the detector by a strong electric field to create a secondary production of photons in gaseous xenon. These two populations of photons are classified as S1 and S2 signals, respectively. Using these signals we reconstruct the energy and position of the interaction and in doing so we can eliminate background events that would otherwise “light up” the detector. My participation in the experiment, while at SLAC, was the creation of the grids that produce the large electric field, along with additional lab activities aimed at testing the grids. While at Stan State, I work on background modeling in order to distinguish a possible WIMP signal from ambient backgrounds.

Charge Sensitive Amplifier (CSA) in cold gas of Liquid Argon (LAr) Time Projection Chamber (TPC)

International Nuclear Information System (INIS)

Bechetoille, E; Mathez, H; Zoccarato, Y

2011-01-01

This paper presents our work on a 8-channel low noise Front-End electronic coupled to a Liquid Argon (LAr) TPC (Time Projection Chamber). Each channel consists of a Charge Sensitive Amplifier (CSA), a band pass filter and a 50 Ohms buffer as line driver. A serial link based on a 'i2c-like' protocol, provides multiple configuration features to the circuit by accessing slow control registers. In this paper, we describe the CSA, the shaper and the slow control part. The feedback network of the CSA is made of a capacitance and a resistor. Their values are respectively 250 fF and 4 MΩ. An input referred noise of, at most, 1500 e- rms must be achieved at -100 deg. C with an input detector capacitance of 250 pF to ensure a correct measurement of the minimal signal of 18000e- (2.88 fC). The power consumption in this cryogenic setup must be less than 40 mW from a 3.3 V power supply.

Measurement of the {sup 234}U(n, f) cross-section with quasi-monoenergetic beams in the keV and MeV range using a Micromegas detector assembly

Energy Technology Data Exchange (ETDEWEB)

Stamatopoulos, A.; Kanellakopoulos, A.; Kalamara, A.; Kokkoris, M.; Michalopoulou, V.; Vlastou, R. [National Technical University of Athens, Department of Physics, Athens (Greece); Diakaki, M. [National Technical University of Athens, Department of Physics, Athens (Greece); European Organisation for Nuclear Research (CERN), Geneva (Switzerland); Tsinganis, A. [European Organisation for Nuclear Research (CERN), Geneva (Switzerland); Axiotis, M.; Lagoyiannis, A. [Tandem Accelerator Laboratory, Institute of Nuclear and Particle Physics, N.C.S.R. Demokritos, Athens (Greece)

2018-01-15

The {sup 234}U neutron-induced fission cross-section has been measured at incident neutron energies of 452, 550, 651 keV and 7.5, 8.7, 10 MeV using the {sup 7}Li (p, n) and the {sup 2}H(d, n) reactions, respectively, relative to the {sup 235}U(n, f) and {sup 238}U(n, f) reference reactions. The measurement was performed at the neutron beam facility of the National Center for Scientific Research ''Demokritos'', using a set-up based on Micromegas detectors. The active mass of the actinide samples and the corresponding impurities were determined via α-spectroscopy using a surface barrier silicon detector. The neutron spectra intercepted by the actinide samples have been thoroughly studied by coupling the NeuSDesc and MCNP5 codes, taking into account the energy and angular straggling of the primary ion beams in the neutron source targets in addition to contributions from competing reactions (e.g. deuteron break-up) and neutron scattering in the surrounding materials. Auxiliary Monte Carlo simulations were performed making combined use of the FLUKA and GEF codes, focusing particularly on the determination of the fission fragment detection efficiency. The developed methodology and the final results are presented. (orig.)

Precision meson spectroscopy. Diffractive production at COMPASS and development of a GEM-based TPC for PANDA

International Nuclear Information System (INIS)

Weitzel, Quirin

2008-01-01

Meson spectroscopy is a unique way to access Quantum Chromo Dynamics (QCD) and learn about its properties. Due to the non-Abelian structure, QCD predicts new states of matter with gluonic degrees of freedom. In particular q anti qg hybrids, which can have spin-exotic quantum numbers forbidden for conventional q anti q mesons, are expected to exist. Such states were searched for in the past, mostly in the light-quark sector. However, the experimental situation is still ambiguous and needs to be clarified. Further insights will certainly also come from the heavy-quark spectroscopy. Several new charmonium-like resonances were for example discovered during the last years, which have to be studied in more detail by future experiments to reveal their nature. Diffractive dissociation reactions at COMPASS provide clean access to meson resonances with masses below 2.5 GeV/c 2 . During a pilot run in 2004 using pion beams on lead targets, a competitive number of π - π - π + final state events were recorded within a few days of data taking. A full partial wave analysis (PWA) of these data has been performed for this dissertation, concentrating on the kinematic domain of large momentum transfer (t' element of [0.1, 1.0] GeV 2 /c 2 ). While well-known mesons are resolved with high quality, also a strong signal consistent with the much disputed hybrid candidate π 1 (1600) is observed in the spin-exotic J PC = 1 -+ partial wave. A Breit-Wigner parameterization yields a mass and width of 1.660 +0.010 -0.074 and 0.269 +0.063 -0.085 GeV/c 2 , respectively. In addition, a first PWA of events with small momentum transfer (t' element of [10 -3 ,10 -2 ] GeV 2 /c 2 ) has been carried out, yielding several high-mass radial-excitation states. In the future, the PANDA experiment at the FAIR facility will perform highprecision spectroscopy in the charm-sector employing anti pp annihilations. Due to its excellent tracking capabilities for charged particles, a time projection chamber (TPC

Studies for a silicon telescope to extend the magnet facility at the DESY test beam

Energy Technology Data Exchange (ETDEWEB)

Tsionou, Dimitra [Deutsches Elektronen-Synchrotron (DESY), Notkestrasse 85, 22607 Hamburg (Germany)

2016-07-01

The International Large Detector is a detector concept for the International Linear Collider (ILC) which uses a Time Projection Chamber (TPC) as its main tracking detector. Within the framework of the LCTPC collaboration, a large prototype (LP) TPC has been built as a demonstrator. The LP has been equipped with Micro-Pattern Gas Detector modules and studied with an electron beam (1-6 GeV) in a 1 Tesla magnetic field at DESY. To extend the capabilities of the test beam setup, an external silicon tracker to be installed inside the magnet will be discussed. The silicon detector will provide high precision space points in front and behind the TPC inside the magnet. It will provide reference tracks that will allow to determine the momentum of the tracks passing the TPC, and which will help in correcting for field distortion effects in the LPTPC volume. In order to meet these requirements, simulation studies have been performed to determine the layout of the system and have placed stringent requirements on the sensor spatial resolution of better than 10 μ m. These studies will be presented along with the hardware options under evaluation.

Neutron-induced fission cross-section measurement of 234U with quasi-monoenergetic beams in the keV and MeV range using micromegas detectors

Science.gov (United States)

Tsinganis, A.; Kokkoris, M.; Vlastou, R.; Kalamara, A.; Stamatopoulos, A.; Kanellakopoulos, A.; Lagoyannis, A.; Axiotis, M.

2017-09-01

Accurate data on neutron-induced fission cross-sections of actinides are essential for the design of advanced nuclear reactors based either on fast neutron spectra or alternative fuel cycles, as well as for the reduction of safety margins of existing and future conventional facilities. The fission cross-section of 234U was measured at incident neutron energies of 560 and 660 keV and 7.5 MeV with a setup based on `microbulk' Micromegas detectors and the same samples previously used for the measurement performed at the CERN n_TOF facility (Karadimos et al., 2014). The 235U fission cross-section was used as reference. The (quasi-)monoenergetic neutron beams were produced via the 7Li(p,n) and the 2H(d,n) reactions at the neutron beam facility of the Institute of Nuclear and Particle Physics at the `Demokritos' National Centre for Scientific Research. A detailed study of the neutron spectra produced in the targets and intercepted by the samples was performed coupling the NeuSDesc and MCNPX codes, taking into account the energy spread, energy loss and angular straggling of the beam ions in the target assemblies, as well as contributions from competing reactions and neutron scattering in the experimental setup. Auxiliary Monte-Carlo simulations were performed with the FLUKA code to study the behaviour of the detectors, focusing particularly on the reproduction of the pulse height spectra of α-particles and fission fragments (using distributions produced with the GEF code) for the evaluation of the detector efficiency. An overview of the developed methodology and preliminary results are presented.

Study of the machine background induced by the PEP-II collider with a mini-TPC. Study of the doubly-charmed decay of the B meson with the detector BaBar; Etude du bruit de fond engendre par la machine PEP-2 a l'aide d'une mini-TPC. Etude de la desintegration doublement charmee du meson B avec le detecteur BaBar

Energy Technology Data Exchange (ETDEWEB)

Trincaz-Duvoid, S

2001-01-01

The work presented in this thesis is divided into two parts. The first one deals with the machine background induced by the PEP-II collider. This study has been performed with a mini-TPC before the start of the BaBar experiment. The second part concerns the measurements of the branching ratio of the decay modes B{sup 0} {yields} D{sup *-}D(*){sup 0}K{sup +} and of the inclusive branching ratio Br(B{sup 0} {yields} K{sup {+-}}X). These measurements have been obtained with the first BaBar data. During the commissioning of the PEP-II collider, the charged tracks rate close to the interaction point has been measured with the mini-TPC. This study has pointed to the fact that the machine background was much higher than predicted by the simulation. These bad background conditions were due to the poor quality of the vacuum in the rings. This relatively high pressure in the rings produces electro-magnetic showers at the interaction point due to beam gas interactions. The potential risks for the BaBar detector due to the machine backgrounds have been clearly pointed out by the studies performed for this thesis. The addition of some collimators and a deep understanding of the machine have greatly reduced the background. Nevertheless, the radiation level in BaBar is continuously monitored in order to protect the detector. The study of the b {yields} cc-bar channel is an important point for the understanding of the overall picture of the B meson decay. With an integrated luminosity of 17.3 fb{sup -1} recorded by the BaBar detector the following branching ratio using exclusive reconstruction technique have been measured: Br(B{sup 0} {yields} D{sup *-}D{sup 0}K{sup +}) = (0.29 {+-} 0.06 (stat) {+-} (syst)) % Br(B{sup 0} {yields} D{sup *-}D{sup *0}K{sup +}) = (1.16 {+-} 0.15 (stat) {+-} 0.16 (syst)) % A partial reconstruction has also been developed. With an integrated luminosity of 8.9 fb{sup -1}, the branching ratio of B{sup 0} into D{sup *-}D{sup 0}K{sup +} has been measured

Developing and evaluating new micropattern gas detectors

International Nuclear Information System (INIS)

Villa, Marco

2014-02-01

Micropattern gas detectors (MPGDs) were introduced in the late 1980s in order to overcome the limited rate capability of traditional proportional counters. Thanks to their microscopic electrode structures, MPGDs are faster and more precise than the previous gas detectors and soon gained popularity. Two of the most successful MPGDs are the gas electron multiplier (GEM) and the micro-mesh gaseous structure (Micromegas). In this thesis I present the features of GEMs and Micromegas, some of their current applications and the research and development that I have done on these technologies. My activity covered two main topics: the test and enhancement of single-mask GEMs for large-area applications and the study of spark-tolerant Micromegas for the upgrade of the ATLAS Small Wheels.

First measurement of the polarisation asymmetry of a gamma-ray beam between 1.7 to 74 MeV with the HARPO TPC

Science.gov (United States)

Gros, P.; Amano, S.; Attié, D.; Bernard, D.; Bruel, P.; Calvet, D.; Colas, P.; Daté, S.; Delbart, A.; Frotin, M.; Geerebaert, Y.; Giebels, B.; Götz, D.; Hashimoto, S.; Horan, D.; Kotaka, T.; Louzir, Marc; Minamiyama, Y.; Miyamoto, S.; Ohkuma, H.; Poilleux, Patrick; Semeniouk, I.; Sizun, P.; Takemoto, A.; Yamaguchi, M.; Wang, S.

2016-07-01

Current γ-ray telescopes suffer from a gap in sensitivity in the energy range between 100 keV and 100 MeV, and no polarisation measurement has ever been done on cosmic sources above 1 MeV. Past and present e+e- pair telescopes are limited at lower energies by the multiple scattering of electrons in passive tungsten converter plates. This results in low angular resolution, and, consequently, a drop in sensitivity to point sources below 1 GeV. The polarisation information, which is carried by the azimuthal angle of the conversion plane, is lost for the same reasons. HARPO is an R&D program to characterise the operation of a gaseous detector (a Time Projection Chamber or TPC) as a high angular-resolution and sensitivity telescope and polarimeter for γ-rays from cosmic sources. It represents a first step towards a future space instrument in the MeV-GeV range. We built and characterised a 30cm cubic demonstrator [SPIE 91441M], and put it in a polarised γ-ray beam at the NewSUBARU accelerator in Japan. Data were taken at photon energies from 1.74MeV to 74MeV and with different polarisation configurations. We describe the experimental setup in beam. We then describe the software we developed to reconstruct the photon conversion events, with special focus on low energies. We also describe the thorough simulation of the detector used to compare results. Finally we will present the performance of the detector as extracted from this analysis and preliminary measurements of the polarisation asymmetry. This beam-test qualification of a gas TPC prototype in a γ-ray beam could open the way to high-performance -ray astronomy and polarimetry in the MeV-GeV energy range in the near future.

Precision meson spectroscopy. Diffractive production at COMPASS and development of a GEM-based TPC for PANDA

Energy Technology Data Exchange (ETDEWEB)

Weitzel, Quirin

2008-09-24

Meson spectroscopy is a unique way to access Quantum Chromo Dynamics (QCD) and learn about its properties. Due to the non-Abelian structure, QCD predicts new states of matter with gluonic degrees of freedom. In particular q anti qg hybrids, which can have spin-exotic quantum numbers forbidden for conventional q anti q mesons, are expected to exist. Such states were searched for in the past, mostly in the light-quark sector. However, the experimental situation is still ambiguous and needs to be clarified. Further insights will certainly also come from the heavy-quark spectroscopy. Several new charmonium-like resonances were for example discovered during the last years, which have to be studied in more detail by future experiments to reveal their nature. Diffractive dissociation reactions at COMPASS provide clean access to meson resonances with masses below 2.5 GeV/c{sup 2}. During a pilot run in 2004 using pion beams on lead targets, a competitive number of {pi}{sup -}{pi}{sup -}{pi}{sup +} final state events were recorded within a few days of data taking. A full partial wave analysis (PWA) of these data has been performed for this dissertation, concentrating on the kinematic domain of large momentum transfer (t' element of [0.1, 1.0] GeV{sup 2}/c{sup 2}). While well-known mesons are resolved with high quality, also a strong signal consistent with the much disputed hybrid candidate {pi}{sub 1}(1600) is observed in the spin-exotic J{sup PC} = 1{sup -+} partial wave. A Breit-Wigner parameterization yields a mass and width of 1.660{sup +0.010}{sub -0.074} and 0.269{sup +0.063}{sub -0.085} GeV/c{sup 2}, respectively. In addition, a first PWA of events with small momentum transfer (t' element of [10{sup -3},10{sup -2}] GeV{sup 2}/c{sup 2}) has been carried out, yielding several high-mass radial-excitation states. In the future, the PANDA experiment at the FAIR facility will perform highprecision spectroscopy in the charm-sector employing anti pp annihilations

ArgonCube: a novel, fully-modular approach for the realization of large-mass liquid argon TPC neutrino detectors

CERN Document Server

Amsler, C; Asaadi, J; Auger, M; Barbato, F; Bay, F; Bishai, M; Bleiner, D; Borgschulte, A; Bremer, J; Cavus, E; Chen, H; De Geronimo, G; Ereditato, A; Fleming, B; Goldi, D; Hanni, R; Kose, U; Kreslo, I; La Mattina, F; Lanni, F; Lissauer, D; Luthi, M; Lutz, P; Marchionni, A; Mladenov, D; Nessi, M; Noto, F; Palamara, O; Raaf, J L; Radeka, V; Rudolph Von Rohr, Ch; Smargianaki, D; Soderberg, M; Strauss, Th; Weber, M; Yu, B; Zeller, G P; Zeyrek, M; CERN. Geneva. SPS and PS Experiments Committee; SPSC

2015-01-01

The Liquid Argon Time Projection Chamber is a prime candidate detector for future neutrino oscillation physics experiments, underground neutrino observatories and proton decay searches. A large international project based on this technology is currently being considered at the future LBNF facility in the United States on the very large mass scale of 40 kton. In this document, following the long standing R&D work conducted over the last years in several laboratories in Europe and in the United States, we intend to propose a novel Liquid Argon TPC approach based on a fully-modular, innovative design, the ArgonCube. The related R&D work will proceed along two main directions; one aimed at on the assessment of the proposed modular detector design, the other on the exploitation of new signal readout methods. Such a strategy will provide high performance while being cost-effective and robust at the same time. According to our plans, we will firstly realize a detector prototype hosted in a cryostat that is a...

Direct formation of a polyamide on Ag(111): Joint XPS and STM studies

Energy Technology Data Exchange (ETDEWEB)

Schmid, Martin; Steinrueck, Hans-Peter; Gottfried, J. Michael [Lehrstuhl fuer Physikalische Chemie II, Universitaet Erlangen-Nuernberg (Germany); Schmitz, Christoph H.; Ikonomov, Julian; Sokolowski, Moritz [Institut fuer Physikalische und Theoretische Chemie, Universitaet Bonn (Germany)

2011-07-01

The polymer poly(p-phenylene terephthalamide) (PPTA) was synthesized on Ag(111) by co-adsorption of the reactive monomer compounds terephthaloyl chloride (TPC) and p-phenylenediamine (PPD) at 300 K. The resulting adsorbate phases were characterised by photoelectron spectroscopy (XPS) and scanning tunneling microscopy (STM). A detailed study of the chemical composition and morphology revealed a complex reaction mechanism, by which the formation of amide bonds leads to folded PPTA polymer chains. According to XPS, the chloride of the TPC precursor is not released as HCl as in the bulk reaction, but remains on the surface as chemisorbed Cl or AgCl. Further temperature-programmed XPS studies of pure TPC on Ag(111) reveal that the molecule decomposes already above 130 K, forming chemisorbed Cl (or AgCl) and a phenylene-dicarbonyl species, which is presumably stabilized by the substrate. The adsorbed chlorine partially desorbs above 800 K as molecular AgCl.

A GEM-TPC in twin configuration for the Super-FRS tracking of heavy ions at FAIR

Science.gov (United States)

García, F.; Grahn, T.; Hoffmann, J.; Jokinen, A.; Kaya, C.; Kunkel, J.; Rinta-Antila, S.; Risch, H.; Rusanov, I.; Schmidt, C. J.; Simon, H.; Simons, C.; Turpeinen, R.; Voss, B.; Äystö, J.; Winkler, M.

2018-03-01

The GEM-TPC described herein will be part of the standard beam-diagnostics equipment of the Super-FRS. This chamber will provide tracking information for particle identification at rates up to 1 MHz on an event-by-event basis. The key requirements of operation for these chambers are: close to 100% tracking efficiency under conditions of high counting rate, spatial resolution below 1 mm and a superb large dynamic range covering projectiles from Z = 1 up to Z = 92. The current prototype consists of two GEM-TPCs inside a single vessel, which are operating independently and have electrical drift fields in opposite directions. The twin configuration is done by flipping one of the GEM-TPCs on the middle plane with respect to the second one. In order to put this development in context, the evolution of previous prototypes will be described and its performances discussed. Finally, this chamber was tested at the University of Jyväskylä accelerator with proton projectiles and at GSI with Uranium, Xenon, fragments and Carbon beams. The results obtained have shown a position resolution between 120 to 300 μm at moderate counting rate under conditions of full tracking efficiency.

Study of bifurcation behavior of two-dimensional turbo product code decoders

International Nuclear Information System (INIS)

He Yejun; Lau, Francis C.M.; Tse, Chi K.

2008-01-01

Turbo codes, low-density parity-check (LDPC) codes and turbo product codes (TPCs) are high performance error-correction codes which employ iterative algorithms for decoding. Under different conditions, the behaviors of the decoders are different. While the nonlinear dynamical behaviors of turbo code decoders and LDPC decoders have been reported in the literature, the dynamical behavior of TPC decoders is relatively unexplored. In this paper, we investigate the behavior of the iterative algorithm of a two-dimensional TPC decoder when the input signal-to-noise ratio (SNR) varies. The quantity to be measured is the mean square value of the posterior probabilities of the information bits. Unlike turbo decoders or LDPC decoders, TPC decoders do not produce a clear 'waterfall region'. This is mainly because the TPC decoding algorithm does not converge to 'indecisive' fixed points even at very low SNR values

Study of bifurcation behavior of two-dimensional turbo product code decoders

Energy Technology Data Exchange (ETDEWEB)

He Yejun [Department of Electronic and Information Engineering, Hong Kong Polytechnic University, Hunghom, Hong Kong (China); Lau, Francis C.M. [Department of Electronic and Information Engineering, Hong Kong Polytechnic University, Hunghom, Hong Kong (China)], E-mail: encmlau@polyu.edu.hk; Tse, Chi K. [Department of Electronic and Information Engineering, Hong Kong Polytechnic University, Hunghom, Hong Kong (China)

2008-04-15

Turbo codes, low-density parity-check (LDPC) codes and turbo product codes (TPCs) are high performance error-correction codes which employ iterative algorithms for decoding. Under different conditions, the behaviors of the decoders are different. While the nonlinear dynamical behaviors of turbo code decoders and LDPC decoders have been reported in the literature, the dynamical behavior of TPC decoders is relatively unexplored. In this paper, we investigate the behavior of the iterative algorithm of a two-dimensional TPC decoder when the input signal-to-noise ratio (SNR) varies. The quantity to be measured is the mean square value of the posterior probabilities of the information bits. Unlike turbo decoders or LDPC decoders, TPC decoders do not produce a clear 'waterfall region'. This is mainly because the TPC decoding algorithm does not converge to 'indecisive' fixed points even at very low SNR values.

SπRIT: A time-projection chamber for symmetry-energy studies

International Nuclear Information System (INIS)

Shane, R.; McIntosh, A.B.; Isobe, T.; Lynch, W.G.; Baba, H.; Barney, J.; Chajecki, Z.; Chartier, M.; Estee, J.; Famiano, M.; Hong, B.; Ieki, K.; Jhang, G.; Lemmon, R.; Lu, F.; Murakami, T.; Nakatsuka, N.; Nishimura, M.; Olsen, R.; Powell, W.

2015-01-01

A time-projection chamber (TPC) called the SAMURAI Pion-Reconstruction and Ion-Tracker (SπRIT) has recently been constructed at Michigan State University as part of an international effort to constrain the symmetry-energy term in the nuclear Equation of State (EoS). The SπRIT TPC will be used in conjunction with the SAMURAI spectrometer at the Radioactive Isotope Beam Factory (RIBF) at RIKEN to measure yield ratios for pions and other light isospin multiplets produced in central collisions of neutron-rich heavy ions, such as 132 Sn+ 124 Sn. The SπRIT TPC can function both as a TPC detector and as an active target. It has a vertical drift length of 50 cm, parallel to the magnetic field. Gas multiplication is achieved through the use of a multi-wire anode plane. Image charges, produced in the 12096 pads, are read out with the recently developed Generic Electronics for TPCs

Tuning the ion selectivity of two-pore channels

Energy Technology Data Exchange (ETDEWEB)

Guo, Jiangtao; Zeng, Weizhong; Jiang, Youxing (UTSMC)

2017-01-17

Organellar two-pore channels (TPCs) contain two copies of a Shaker-like six-transmembrane (6-TM) domain in each subunit and are ubiquitously expressed in plants and animals. Interestingly, plant and animal TPCs share high sequence similarity in the filter region, yet exhibit drastically different ion selectivity. Plant TPC1 functions as a nonselective cation channel on the vacuole membrane, whereas mammalian TPC channels have been shown to be endo/lysosomal Na+-selective or Ca2+-release channels. In this study, we performed systematic characterization of the ion selectivity of TPC1 from Arabidopsis thaliana (AtTPC1) and compared its selectivity with the selectivity of human TPC2 (HsTPC2). We demonstrate that AtTPC1 is selective for Ca2+ over Na+, but nonselective among monovalent cations (Li+, Na+, and K+). Our results also confirm that HsTPC2 is a Na+-selective channel activated by phosphatidylinositol 3,5-bisphosphate. Guided by our recent structure of AtTPC1, we converted AtTPC1 to a Na+-selective channel by mimicking the selectivity filter of HsTPC2 and identified key residues in the TPC filters that differentiate the selectivity between AtTPC1 and HsTPC2. Furthermore, the structure of the Na+-selective AtTPC1 mutant elucidates the structural basis for Na+ selectivity in mammalian TPCs.

Effect of Ultrasonic-Assisted Extraction on Phenolic Content of Avocado

International Nuclear Information System (INIS)

Rafidah Husen; Andou, Y.; Amin Ismail; Shirai, Y.

2014-01-01

This study evaluate the effect of ultrasonic application in the extraction process on total phenolic content (TPC) of Hass avocado (Persea americana Mill) pulp. In this study, the solid/ solvent ratio of 1/30 (wt/ vol) and extraction temperature of 40 degree Celsius gave higher TPC value. This ratio and temperature was applied in the ultrasonic-assisted extraction (UAE) of avocado pulp. This study then compared the TPC obtained from the avocado pulp extract without involving ultrasonic and the TPC obtained from the UAE. Results showed that the TPC value of avocado pulp was significantly higher in the UAE (235.77 mg GAE/ 100g dried sample) compared to the TPC in the non-UAE (166.32 mg GAE/ 100g dried sample). The increase in the TPC was between ∼31 % and ∼41 % when 5 to 20 min of ultra sonication applied in the extraction. Ultra sonication duration of 15 min gave the highest TPC where the value was significantly higher compared to the other duration. (author)

ATLAS MPGD production status

CERN Document Server

Schioppa, Marco; The ATLAS collaboration

2018-01-01

Micromegas (MICRO MEsh GAseous Structure) chambers are Micro-Pattern Gaseous Detectors designed to provide a high spatial resolution and reasonable good time resolution in highly irradiated environments. In 2007 an ambitious long-term R\\&D activity was started in the context of the ATLAS experiment, at CERN: the Muon ATLAS Micromegas Activity (MAMMA). After years of tests on prototypes and technology breakthroughs, Micromegas chambers were chosen as tracking detectors for an upgrade of the ATLAS Muon Spectrometer. These novel detectors will be installed in 2020 at the end of the second long shutdown of the Large Hadron Collider, and will serve mainly as precision detectors in the innermost part of the forward ATLAS Muon Spectrometer. Four different types of Micromegas modules, eight layers each, up to $3 m^2$ area (of unprecedented size), will cover a surface of $150 m^2$ for a total active area of about $1200 m^2$. With this upgrade the ATLAS muon system will maintain the full acceptance of its excellent...

Precision tracking at high background rates with the ATLAS muon spectrometer

CERN Document Server

Hertenberger, Ralf; The ATLAS collaboration

2012-01-01

Since start of data taking the ATLAS muon spectrometer performs according to specification. End of this decade after the luminosity upgrade of LHC by a factor of ten the proportionally increasing background rates require the replacement of the detectors in the most forward part of the muon spectrometer to ensure high quality muon triggering and tracking at background hit rates of up to 15,kHz/cm$^2$. Square meter sized micromegas detectors together with improved thin gap trigger detectors are suggested as replacement. Micromegas detectors are intrinsically high rate capable. A single hit spatial resolution below 40,$mu$m has been shown for 250,$mu$m anode strip pitch and perpendicular incidence of high energy muons or pions. The ongoing development of large micromegas structures and their investigation under non-perpendicular incidence or in high background environments requires precise and reliable monitoring of muon tracks. A muon telescope consisting of six small micromegas works reliably and is presently ...

Expressing emotions in blogs

DEFF Research Database (Denmark)

Rodriguez-Hidalgo, Carmina Rodriguez-Hidalgo; Tan, Ed S.; Verlegh, Peeter

2017-01-01

Textual paralanguage cues (TPC) have been signaled as effective emotion transmitters online. Though several studies have investigated their properties and occurrence, there remains a gap concerning their communicative impact within specific psychological processes, such as the social sharing...... of emotion (SSE, Rimé, 2009). This study content-analyzed Live Journal blogposts for the occurrence of TPC in three phases of online SSE: initiation, feedback and repost. We compared these to TPC on a second type of emotional expression, emotional venting. Based on Social Information processing theory (SIP......, Walther, 1992), and on the Emotional Mimicry in Context (EMC, Hess & Fischer, 2013) framework, we study predictive relationships in TPC usage in our phased model of online SSE. Results showed that TPC prevailed in SSE blogposts and strongly dominated in emotional venting posts. TPC was more common...

Prototype board development for the validation of the VMM ASICs for the New Small Wheel ATLAS upgrade project

CERN Document Server

Gkountoumis, Panagiotis; The ATLAS collaboration

2018-01-01

The VMM is a custom Application Specific Integrated Circuit (ASIC) which was designed to be used in the front-end readout electronics of both micromegas (MM) and small Thin Gap Chambers (sTGC) detectors of the New Small Wheel (NSW) Phase-I upgrade project of the ATLAS experiment. A new version of the VMM was recently fabricated and for that reason various prototype boards, the micromegas Front-End (MMFE1) and the General Purpose VMM (GPVMM), have been fabricated and extensively tested in order to validate the functionality of the ASIC. These boards use commercial Field Programmable Gate Arrays (FPGAs) for direct communication with computers which is achieved through 10/100/1000 Mbps Ethernet and UDP/IP protocols. The low noise performance of these boards gave the opportunity to be used in various test beams with micromegas detectors for validating the VMM and for performance studies of the sTGC detectors. A detailed description of the boards along with the results of the test beam and the detector studies wi...

In vitro mechanical evaluation of a novel pin-sleeve system for external fixation of distal limb fractures in horses: a proof of concept study.

Science.gov (United States)

Brianza, Stefano; Brighenti, Vittoria; Boure, Ludovic; Sprenger, Victor; Pearce, Simon; Schwieger, Karsten

2010-07-01

To evaluate the efficacy of a novel pin-sleeve cast (PSC) system for external fixation of distal limb fractures in horses and to compare it with the transfixation pin cast (TPC) system. Experimental. One bone substitute each was used for the TPC and PSC systems. The PSC was tested in 4 configurations characterized by different pin preloads. Specimens were loaded in axial compression in the elastic range. Variables compared statistically were: bone substitute axial displacement and axial strain measured above implants with strain gauges. Pin preload was correlated with the variables investigated. Load to failure and a fatigue tests supplemented the investigation. The PSC configuration with the highest pin preload showed a significantly lower axial displacement compared with the TPC. No significant differences were observed between all other PSC configurations and the TPC. All PSC systems had a significant decrease in recorded strain compared with the TPC system. Pin axial preload inversely correlated with axial displacement but had no effect on axial strain. In the failure test, the PSC encountered plastic deformation earlier than the TPC. In the fatigue test, the PSC ran >200,000 cycles. Preliminary in vitro tests showed that the PSC system significantly reduced peri-implant strain while concurrently having comparable axial displacement to the TPC system. The PSC system has the potential to reduce the risk of pin loosening in horses.

Development and tests of an anode readout TPC with high track separability for large solid angle relativistic ion experiments

International Nuclear Information System (INIS)

Lindenbaum, S.J.; Foley, K.J.; Eiseman, S.E.

1988-01-01

We have developed, constructed and tested an anode readout TPC with high track separability which is suitable for large solid angle relativistic ion experiments. The readout via rows of short anode wires parallel to the beam has been found in tests to allow two-track separability of ∼2-3 mm. The efficiency of track reconstruction for events from a target, detected inside the MPS 5 KG magnet, is estimated to be >90% for events made by incident protons and pions. 15 GeV/c x A Si ion beams at a rate of ∼25 K per AGS pulse were permitted to course through the chamber and did not lead to any problems. When the gain was reduced to simulate the total output of a minimum ionizing particle, many Si ion tracks were also detected simultaneously with high efficiency. The resolution along the drift direction (parallel to the MPS magnetic field and perpendicular to the beam direction) was <1 mm and the resolution along the other direction /perpendicular/ to the beam direction was <1 mm also. 3 refs., 5 figs

High-performance size-exclusion chromatography studies on the formation and distribution of polar compounds in camellia seed oil during heating*

Science.gov (United States)

Feng, Hong-xia; Sam, Rokayya; Jiang, Lian-zhou; Li, Yang; Cao, Wen-ming

2016-01-01

Camellia seed oil (CSO) is rich in oleic acid and has a high number of active components, which give the oil high nutritional value and a variety of biological activity. The aim of the present study was to determine the changes in the content and distribution of total polar compounds (TPC) in CSO during heating. TPC were isolated by means of preparative flash chromatography and further analyzed by high-performance size-exclusion chromatography (HPSEC). The TPC content of CSO increased from 4.74% to 25.29%, showing a significantly lower formation rate as compared to that of extra virgin olive oil (EVOO) and soybean oil (SBO) during heating. Furthermore, heating also resulted in significant differences (P<0.05) in the distribution of TPC among these oils. Though the content of oxidized triacylglycerol dimers, oxidized triacylglycerol oligomers, and oxidized triacylglycerol monomers significantly increased in all these oils, their increased percentages were much less in CSO than those in EVOO, indicating that CSO has a greater ability to resist oxidation. This work may be useful for the food oil industry and consumers in helping to choose the correct oil and to decide on the useful lifetime of the oil. PMID:27819135

Simulation studies for a high resolution time projection chamber at the international linear collider

Energy Technology Data Exchange (ETDEWEB)

Muennich, A.

2007-03-26

The International Linear Collider (ILC) is planned to be the next large accelerator. The ILC will be able to perform high precision measurements only possible at the clean environment of electron positron collisions. In order to reach this high accuracy, the requirements for the detector performance are challenging. Several detector concepts are currently under study. The understanding of the detector and its performance will be crucial to extract the desired physics results from the data. To optimise the detector design, simulation studies are needed. Simulation packages like GEANT4 allow to model the detector geometry and simulate the energy deposit in the different materials. However, the detector response taking into account the transportation of the produced charge to the readout devices and the effects ofthe readout electronics cannot be described in detail. These processes in the detector will change the measured position of the energy deposit relative to the point of origin. The determination of this detector response is the task of detailed simulation studies, which have to be carried out for each subdetector. A high resolution Time Projection Chamber (TPC) with gas amplification based on micro pattern gas detectors, is one of the options for the main tracking system at the ILC. In the present thesis a detailed simulation tool to study the performance of a TPC was developed. Its goal is to find the optimal settings to reach an excellent momentum and spatial resolution. After an introduction to the present status of particle physics and the ILC project with special focus on the TPC as central tracker, the simulation framework is presented. The basic simulation methods and implemented processes are introduced. Within this stand-alone simulation framework each electron produced by primary ionisation is transferred through the gas volume and amplified using Gas Electron Multipliers (GEMs). The output format of the simulation is identical to the raw data from a

Tests of Micro-Pattern Gaseous Detectors for active target time projection chambers in nuclear physics

Energy Technology Data Exchange (ETDEWEB)

Pancin, J., E-mail: pancin@ganil.fr [GANIL, CEA/DSM-CNRS/IN2P3, Bvd H. Becquerel, Caen (France); Damoy, S.; Perez Loureiro, D. [GANIL, CEA/DSM-CNRS/IN2P3, Bvd H. Becquerel, Caen (France); Chambert, V.; Dorangeville, F. [IPNO, CNRS/IN2P3, Orsay (France); Druillole, F. [CEA, DSM/Irfu/SEDI, Gif-Sur-Yvette (France); Grinyer, G.F. [GANIL, CEA/DSM-CNRS/IN2P3, Bvd H. Becquerel, Caen (France); Lermitage, A.; Maroni, A.; Noël, G. [IPNO, CNRS/IN2P3, Orsay (France); Porte, C.; Roger, T. [GANIL, CEA/DSM-CNRS/IN2P3, Bvd H. Becquerel, Caen (France); Rosier, P. [IPNO, CNRS/IN2P3, Orsay (France); Suen, L. [GANIL, CEA/DSM-CNRS/IN2P3, Bvd H. Becquerel, Caen (France)

2014-01-21

Active target detection systems, where the gas used as the detection medium is also a target for nuclear reactions, have been used for a wide variety of nuclear physics applications since the eighties. Improvements in Micro-Pattern Gaseous Detectors (MPGDs) and in micro-electronics achieved in the last decade permit the development of a new generation of active targets with higher granularity pad planes that allow spatial and time information to be determined with unprecedented accuracy. A novel active target and time projection chamber (ACTAR TPC), that will be used to study reactions and decays of exotic nuclei at facilities such as SPIRAL2, is presently under development and will be based on MPGD technology. Several MPGDs (Micromegas and Thick GEM) coupled to a 2×2 mm{sup 2} pixelated pad plane have been tested and their performances have been determined with different gases over a wide range of pressures. Of particular interest for nuclear physics experiments are the angular and energy resolutions. The angular resolution has been determined to be better than 1° FWHM for short traces of about 4 cm in length and the energy resolution deduced from the particle range was found to be better than 5% for 5.5 MeV α particles. These performances have been compared to Geant4 simulations. These experimental results validate the use of these detectors for several applications in nuclear physics.

Tests of Micro-Pattern Gaseous Detectors for active target time projection chambers in nuclear physics

International Nuclear Information System (INIS)

Pancin, J.; Damoy, S.; Perez Loureiro, D.; Chambert, V.; Dorangeville, F.; Druillole, F.; Grinyer, G.F.; Lermitage, A.; Maroni, A.; Noël, G.; Porte, C.; Roger, T.; Rosier, P.; Suen, L.

2014-01-01

Active target detection systems, where the gas used as the detection medium is also a target for nuclear reactions, have been used for a wide variety of nuclear physics applications since the eighties. Improvements in Micro-Pattern Gaseous Detectors (MPGDs) and in micro-electronics achieved in the last decade permit the development of a new generation of active targets with higher granularity pad planes that allow spatial and time information to be determined with unprecedented accuracy. A novel active target and time projection chamber (ACTAR TPC), that will be used to study reactions and decays of exotic nuclei at facilities such as SPIRAL2, is presently under development and will be based on MPGD technology. Several MPGDs (Micromegas and Thick GEM) coupled to a 2×2 mm 2 pixelated pad plane have been tested and their performances have been determined with different gases over a wide range of pressures. Of particular interest for nuclear physics experiments are the angular and energy resolutions. The angular resolution has been determined to be better than 1° FWHM for short traces of about 4 cm in length and the energy resolution deduced from the particle range was found to be better than 5% for 5.5 MeV α particles. These performances have been compared to Geant4 simulations. These experimental results validate the use of these detectors for several applications in nuclear physics

Measurement of electrons from heavy-flavour hadron decays in p-Pb collisions at $\\sqrt{s_{NN}} = 5.02$ TeV using TPC and EMCal detectors with ALICE at LHC

CERN Document Server

Jahnke, Cristiane

Heavy-ion collisions are a powerful tool to study hot and dense QCD matter, the so-called Quark Gluon Plasma (QGP). Since heavy quarks (charm and beauty) are dominantly produced in the early stages of the collision, they experience the complete evolution of the system. Measurements of electrons from heavy-flavour hadron decay is one possible way to study the interaction of these particles with the QGP. With ALICE at LHC, electrons can be identified with high efficiency and purity. A strong suppression of heavy-flavour decay electrons has been observed at high $p_{m T}$ in Pb-Pb collisions at 2.76 TeV. Measurements in p-Pb collisions are crucial to understand cold nuclear matter effects on heavy-flavour production in heavy-ion collisions. The spectrum of electrons from the decays of hadrons containing charm and beauty was measured in p-Pb collisions at $\\sqrt = 5.02$ TeV. The heavy flavour decay electrons were measured by using the Time Projection Chamber (TPC) and the Electromagnetic Calorimeter (EMCal) detec...

HFE and Spherical Cryostats MC Study

International Nuclear Information System (INIS)

Brodsky, Jason P.

2016-01-01

The copper vessel containing the nEXO TPC is surrounded by a buffer of HFE, a liquid refrigerant with very low levels of radioactive element contamination. The HFE is contained within the cryostat's inner vessel, which is in turn inside the outer vessel. While some HFE may be necessary for stable cooling of nEXO, it is possible that using substantially more than necessary for thermal reasons will help reduce backgrounds originating in the cryostats. Using a larger amount of HFE is accomplished by making the cryostat vessels larger. By itself, increasing the cryostat size somewhat increases the background rate, as the thickness of the cryostat wall must increase at larger sizes. However, the additional space inside the cryostat will be filled with HFE which can absorb gamma rays headed for the TPC. As a result, increasing the HFE reduces the number of backgrounds reaching the TPC. The aim of this study was to determine the relationship between HFE thickness and background rate. Ultimately, this work should support choosing a cryostat and HFE size that satisfies nEXO's background budget. I have attempted to account for every consequence of changing the cryostat size, although naturally this remains a work in progress until a final design is achieved. At the moment, the scope of the study includes only the spherical cryostat design. This study concludes that increasing cryostat size reduces backgrounds, reaching neglible backgrounds originating from the cryostat at the largest sizes. It also shows that backgrounds originating from the inherent radioactivity of the HFE plateau quickly, so may be considered essentially fixed at any quantity of HFE.

First operation and performance of a 200 lt double phase LAr LEM-TPC with a 40x76 $\\cm^2$ readout

CERN Document Server

Badertscher, A; Degunda, U; Epprecht, L; Gendotti, A; Horikawa, S; Knecht, L; Natterer, D Lussi G; Nguyen, K; Resnati, F; Rubbia, A; Viant, T

2013-01-01

In this paper we describe the design, construction, and operation of a first large area double-phase liquid argon Large Electron Multiplier Time Projection Chamber (LAr LEM-TPC). The detector has a maximum drift length of 60 cm and the readout consists of a $40\\times 76$ cm$^2$ LEM and 2D projective anode to multiply and collect drifting charges. Scintillation light is detected by means of cryogenic PMTs positioned below the cathode. To record both charge and light signals, we have developed a compact acquisition system, which is scalable up to ton-scale detectors with thousands of charge readout channels. The acquisition system, as well as the design and the performance of custom-made charge sensitive preamplifiers, are described. The complete experimental setup has been operated for a first time during a period of four weeks at CERN in the cryostat of the ArDM experiment, which was equipped with liquid and gas argon purification systems. The detector, exposed to cosmic rays, recorded events with a single-ch...

The influence of impurities on the coefficients of transportation

International Nuclear Information System (INIS)

Selmi, Aloine

2011-01-01

The goal of this Masters project was to build a water filtration plant using a Micromegas detector. (You need to explain at least how Micromegas can be used in filtration plants, and to filtrate what.) This new generation of devices have good resolution, low background, fast response with the highest efficiency and good sensitivity in the range of natural radioactivity. The central part of this work was to describe the development of a detection plane. A small Micomegas prototype, was built in CNSTN (Tunisia), and is devoted to study electron transport properties in a gas. This manuscript describes the development of a filtration plant using a Micromegas gas detector. This detector must be filled with Xenon 98 pour cent and C F 4 2 pour cent at pressure varying between 1 and 4 bar. I realized the need to have a rigorously high purity gas; I studied in depth the influence of impurities on the parameters characterizing the detector: drift velocity of electron in the gas, their longitudinal and transverse diffusion and the gas gain, the electron attachment while varying the proportions of impurities and the gas pressure. These studies have been done using a simulation program called M agboltz . Another simulation program G EANT4 w as used to better understand the interactions and radiation field. I also used two other programs, G arfield a nd M axwell , to simulate the electric field in the detector. I reached the stage of near completion of this treatment plant but the necessary equipment could not be purchased, simply because its cost was too high. To complete my masters, I started the design of a gamma camera filled by Xenon gas at high pressure and based on Micromegas - micro pattern.

Single-phase ProtoDUNE, the Prototype of a Single-Phase Liquid Argon TPC for DUNE at the CERN Neutrino Platform

CERN Document Server

Cavanna, F; Touramanis, C

2017-01-01

ProtoDUNE-SP is the single-phase DUNE Far Detector prototype that is under construction and will be operated at the CERN Neutrino Platform (NP) starting in 2018. It was proposed to the CERN SPSC in June 2015 (SPSC-P-351) and was approved in December 2015 as experiment NP04 (ProtoDUNE). ProtoDUNE-SP, a crucial part of the DUNE effort towards the construction of the first DUNE 10-kt fiducial mass far detector module (17 kt total LAr mass), is a significant experiment in its own right. With a total liquid argon (LAr) mass of 0.77 kt, it represents the largest monolithic single phase LArTPC detector to be built to date. It is housed in an extension to the EHN1 hall in the North Area, where the CERN NP is providing a new dedicated charged-particle test beamline. ProtoDUNE-SP aims to take its first beam data before the LHC long shutdown (LS2) at the end of 2018. ProtoDUNE-SP prototypes the designs of most of the single-phase DUNE far detector module (DUNE-SP) components at a 1:1 scale, with an extrapolation of abo...

Experimental development of a liquid xenon Compton telescope for functional medical imaging

International Nuclear Information System (INIS)

Oger, Tugdual

2012-01-01

3γ imaging is a new nuclear medical imaging technique which has been suggested by Subatech laboratory. This technique involves locating three-dimensional position of the decay of an innovative radioisotope (β + ,γ) emitter, the 44 Sc. The principle consist in the detection of two photons of 511 keV gamma rays from the decay of the positron, provided by a PET ring detector, associated to the detection of the third photon by a Liquid xenon Compton telescope. The energy deposited in the interaction between the photon and xenon and its position are identified by measuring the ionization signal with a Micromegas chamber (Micro-Mesh Gaseous Structure), while the trigger and time measurement of the interaction are provided by the detection of the scintillation signal. The principle of the TPC is thus used to Compton imaging. In order to demonstrate experimentally the feasibility of imaging 3γ, a small prototype, XEMIS (Xenon Medical Imaging System) was developed. This thesis is an important step towards the proof of feasibility. In this work are exposed the characterization of the detector response for a beam of 511 keV gamma rays and the analysis of data derived from it. The measurement of energy and time resolutions will be presented, as well as the purity of the liquid xenon. (author) [fr

Near-intrinsic energy resolution for 30–662 keV gamma rays in a high pressure xenon electroluminescent TPC

International Nuclear Information System (INIS)

Álvarez, V.; Borges, F.I.G.M.; Cárcel, S.; Castel, J.; Cebrián, S.; Cervera, A.; Conde, C.A.N.; Dafni, T.; Dias, T.H.V.T.; Díaz, J.

2013-01-01

We present the design, data and results from the NEXT prototype for Double Beta and Dark Matter (NEXT-DBDM) detector, a high-pressure gaseous natural xenon electroluminescent time projection chamber (TPC) that was built at the Lawrence Berkeley National Laboratory. It is a prototype of the planned NEXT-100 136 Xe neutrino-less double beta decay (0νββ) experiment with the main objectives of demonstrating near-intrinsic energy resolution at energies up to 662 keV and of optimizing the NEXT-100 detector design and operating parameters. Energy resolutions of ∼1% FWHM for 662 keV gamma rays were obtained at 10 and 15 atm and ∼5% FWHM for 30 keV fluorescence xenon X-rays. These results demonstrate that 0.5% FWHM resolutions for the 2459 keV hypothetical neutrino-less double beta decay peak are realizable. This energy resolution is a factor 7–20 better than that of the current leading 0νββ experiments using liquid xenon and thus represents a significant advancement. We present also first results from a track imaging system consisting of 64 silicon photo-multipliers recently installed in NEXT–DBDM that, along with the excellent energy resolution, demonstrates the key functionalities required for the NEXT-100 0νββ search

Measurements of ion mobility and GEM discharge studies for the upgrade of the ALICE time projection chamber

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00507268

2018-02-20

ALICE is one of the four experiments at the Large Hadron Collider (LHC). The quark-gluon plasma, which is predominantly produced in lead-lead collisions at LHC, is of particular interest for ALICE. After the long shut-down 2 (2019-2021) the LHC will provide lead-lead collisions at an increased interaction rate of 50 kHz. In order to examine every event at this interaction rate the ALICE Time Projection Chamber (TPC) needs to be upgraded. The TPC’s ReadOut Chambers (ROCs) are currently multi-wire proportional chambers. To prevent space charge build-up of slow ions, drifting from the ROCs into the TPC, a gating grid is used. The corresponding closure time imposes a dead time on the TPC read out, which prohibits data taking at a readout rate higher than 3 kHz. New ROCs have therefore been designed, relying on stacks of Gas Electron Multiplier (GEM) foils for the gas amplification, allowing for continuous readout. With the new ROCs, a certain fraction of ions will be drifting at all time into the TPC. Knowing t...

Improvement of surface planarity measurements by temperature correction and structural simulations

Energy Technology Data Exchange (ETDEWEB)

Herrmann, Maximilian; Biebel, Otmar; Bortfeldt, Jonathan; Flierl, Bernhard; Hertenberger, Ralf; Loesel, Philipp; Mueller, Ralph [LMU Muenchen (Germany); Zibell, Andre [JMU Wuerzburg (Germany)

2016-07-01

Novel micro pattern gaseous detectors, like Micromegas, for particle physics experiments require precise flat active layers of 2-3 m{sup 2} in size. A construction procedure developed at LMU for 2 m{sup 2} sized Micromegas achieves surface planarities with a RMS below 30 μm. The measurements were performed using a laser distance sensor attached to a coordinate measurement machine. Studies were made to investigate the influence of temperature variations on these measurements. The temperature is monitored by several sensors. We present results containing corrections of the measurements in respect to temperature changes. In addition simulations with the FEM program ANSYS are compared to measured detector panel deformations introduced by forces, in order to study their effect on the surface planarity.

Design studies for a tracking upgrade of the Crystal Barrel experiment at ELSA and installation of tracking test bench

International Nuclear Information System (INIS)

Winnebeck, Alexander

2009-01-01

Ever since mankind was interested in the understanding of the universe and especially the matter in it. The fundamental building blocks of matter seem to be quarks and gluons, whose interactions are investigated in hadron physics. To study this strong interaction different experimental approaches can be used. One way is to do spectroscopy similar to atomic physics. The Crystal Barrel experiment at ELSA performs spectroscopy of nucleons to learn more about the strong interaction. A major improvement of this experimental setup will be the introducing of charged particle tracking as it is shown in this thesis. Different detector concepts are discussed concerning feasibility, material budget and especially momentum resolution. It turns out that a Time Projection Chamber (TPC) is the optimal solution. Then it is shown how a prototype TPC is tested using a newly installed tracking test bench with an electron beam, and obtained results are presented. The design of the final TPC and its integration into the Crystal Barrel experiment are discussed as well as methods to calibrate the detector. (orig.)

Design studies for a tracking upgrade of the Crystal Barrel experiment at ELSA and installation of tracking test bench

Energy Technology Data Exchange (ETDEWEB)

Winnebeck, Alexander

2009-12-17

Ever since mankind was interested in the understanding of the universe and especially the matter in it. The fundamental building blocks of matter seem to be quarks and gluons, whose interactions are investigated in hadron physics. To study this strong interaction different experimental approaches can be used. One way is to do spectroscopy similar to atomic physics. The Crystal Barrel experiment at ELSA performs spectroscopy of nucleons to learn more about the strong interaction. A major improvement of this experimental setup will be the introducing of charged particle tracking as it is shown in this thesis. Different detector concepts are discussed concerning feasibility, material budget and especially momentum resolution. It turns out that a Time Projection Chamber (TPC) is the optimal solution. Then it is shown how a prototype TPC is tested using a newly installed tracking test bench with an electron beam, and obtained results are presented. The design of the final TPC and its integration into the Crystal Barrel experiment are discussed as well as methods to calibrate the detector. (orig.)

Systematic studies on the reconstruction efficiency and accuracy of a track drift chamber

International Nuclear Information System (INIS)

Appelshaeuser, H.

1993-02-01

The author has studied the reconstruction efficiency of the NA35-TPC by means of a simulation of the tracks by means of laser radiation. He has obtained results on the diffusion constant and the track resolution. (HSI) [de

Study of reconstruction methods for a time projection chamber with GEM gas amplification system

Energy Technology Data Exchange (ETDEWEB)

Diener, R.

2006-12-15

A new e{sup +}e{sup -} linear collider with an energy range up to 1TeV is planned in an international collaboration: the International Linear Collider (ILC). This collider will be able to do precision measurements of the Higgs particle and of physics beyond the Standard Model. In the Large Detector Concept (LDC) - which is one proposal for a detector at the ILC - a Time Projection Chamber (TPC) is foreseen as the main tracking device. To meet the requirements on the resolution and to be able to work in the environment at the ILC, the application of new gas amplification technologies in the TPC is necessary. One option is an amplification system based on Gas Electron Multipliers (GEMs). Due to the - in comparison with older technologies - small spatial width of the signals, this technology poses new requirements on the readout structures and the reconstruction methods. In this work, the performance and the systematics of different reconstruction methods have been studied, based on data measured with a TPC prototype in high magnetic fields of up to 4T and data from a Monte Carlo simulation. The latest results of the achievable point resolution are presented and their limitations have been investigated. (orig.)

Study of reconstruction methods for a time projection chamber with GEM gas amplification system

International Nuclear Information System (INIS)

Diener, R.

2006-12-01

A new e + e - linear collider with an energy range up to 1TeV is planned in an international collaboration: the International Linear Collider (ILC). This collider will be able to do precision measurements of the Higgs particle and of physics beyond the Standard Model. In the Large Detector Concept (LDC) - which is one proposal for a detector at the ILC - a Time Projection Chamber (TPC) is foreseen as the main tracking device. To meet the requirements on the resolution and to be able to work in the environment at the ILC, the application of new gas amplification technologies in the TPC is necessary. One option is an amplification system based on Gas Electron Multipliers (GEMs). Due to the - in comparison with older technologies - small spatial width of the signals, this technology poses new requirements on the readout structures and the reconstruction methods. In this work, the performance and the systematics of different reconstruction methods have been studied, based on data measured with a TPC prototype in high magnetic fields of up to 4T and data from a Monte Carlo simulation. The latest results of the achievable point resolution are presented and their limitations have been investigated. (orig.)

Fabrication of Mesoporous Silica/Alumina Hybrid Membrane Film Nanocomposites using Template Sol-Gel Synthesis of Amphiphilic Triphenylene

Science.gov (United States)

Lintang, H. O.; Jalani, M. A.; Yuliati, L.; Salleh, M. M.

2017-05-01

Herein we reported that by introducing a one-dimensional (1D) substrate with a porous structure such as anodic aluminum oxide (AAO) membrane, mesoporous silica/alumina hybrid nanocomposites were successfully fabricated by using amphiphilic triphenylene (TPC10TEG) as a template in sol-gel synthesis (TPC10TEG/silicahex). For the optical study of the nanocomposites, TPC10TEG/silicahex showed absorption peak at 264 nm due to the ordered and long-range π-π stacking of the disc-like aromatic triphenylene core. Moreover, the hexagonal arrangement of TPC10TEG/silicahex was proven based on their diffraction peaks of d 100 and d 200 at 2θ = 2.52° and 5.04° and images of transmission electron microscopy (TEM), respectively. For fabrication of mesoporous silica/alumina hybrid membrane, TPC10TEG/silicahex was drop-casted onto AAO membrane for penetration into the porous structure via gravity. X-ray diffraction (XRD) analysis on the resulted hybrid nanocomposites showed that the diffraction peaks of d 100 and d 200 of TPC10TEG/silicahex were still preserved, indicating that the hexagonal arrangements of mesoporous silica were maintained even on AAO substrate. The morphology study on the hybrid nanocomposites using TEM, scanning electron microscope (SEM) and field emission scanning electron microscope (FE-SEM) showed the successful filling of most AAO channels with the TPC10TEG/silicahex nanocomposites.

MUNU: study of the neutrino-electron scattering; MUNU: etude de la diffusion neutrino-electron

Energy Technology Data Exchange (ETDEWEB)

Cerna, C

2000-11-01

MUNU is an experiment dedicated to electron-neutrino scattering studies and in particular to neutrino magnetic moment search at a nuclear power plant in Bugey (France). MUNU is based on a gaseous time projection chamber (TPC) immersed in 8 tons of liquid scintillator acting as an active anti-Compton shielding. A preliminary analysis of the first results of this experiment corresponding to about 24 days of data collecting draws a line on the value of the neutrino magnetic moment: {mu}{sub {nu}}-bar{sub {sub e}} {<=} 1.97 10{sup -10} {mu}{sub B} (68% confidence level). All along this work, it is shown that the combined use of a TPC and of a light detection system is valuable for discriminating particles and for discarding signals from background noise.

Photosynthetic capacity of 'Niagara Rosada' grapes grown under transparent plastic covering

Directory of Open Access Journals (Sweden)

Bruna Corrêa da Silva de Deus

2016-06-01

Full Text Available ABSTRACT: New techniques in tropical regions such as use of transparent plastic covering (TPC, have been employed in grapes to avoid the wetting leaves and fruits, which can reduce the occurrence of fungal diseases, reduce the use of sprays, and reduce damage caused by hail and high winds. TPC may significantly affect the photosynthetic rates of grapevines cultivated in tropical regions, and thus have strong effects on plant productivity and improve fruit quality. However, in the North of Rio de Janeiro region there are lacks of studies related to TPC effects on photosynthetic capacity. The objective of this study was to evaluate the photosynthetic capacity in 'Niagara Rosada' vines grown under TPC and without transparent plastic covering (WTPC. The experiment was conducted between April and June 2013, on Tabuinha farm, located in the 3rd district of São Fidélis, Rio de Janeiro State, Brazil. A completely randomized block design was used with two treatments (TPC and WTPC and twelve replications. Evaluations consisted of climatological variables, gas exchange and maximum quantum efficiency of open photosystem II centers-quantum yield (Fv/Fm It was possible to observe that under TPC maximum temperature increase of 2.3°C, relative humidity reduced 1.5%, vapor pressure deficit increase 0.4kPa, and light intensity reduced 47.7%. These changes did not cause photochemical damage to the leaves. The TPC promoted higher net photosynthetic rate at 800h, which was associated with higher stomatal conductance. Thus, the TPC used in the northern region of Rio de Janeiro State did not impair the photosynthetic capacity of 'Niagara Rosada' vines.

Determination of the equation of state of asymmetric nuclear matter

Energy Technology Data Exchange (ETDEWEB)

Tsang, Manyee Betty [Michigan State Univ., East Lansing, MI (United States)

2016-12-30

A new Time Projection Chamber (TPC), called the SπRIT (SAMURAI pion Reconstruction Ion Tracker) TPC was constructed and used successfully in two experiments with the SAMURAI spectrometer at RIKEN, Japan to study the equation of state of neutron rich matter. As a result of the project, the SπRIT collaboration, an international collaboration consisting of groups from US, Japan, Korea, Poland, China and Germany, has been formed to pursue the science opportunities provided by the SπRIT TPC. After completion of the TPC and the two experiments, the collaboration continues to develop the software to analyze the SπRIT experiments and extract constraints of symmetry energy at supra-saturation densities. Over 250 TB of data have been obtained in the last SπRIT TPC experimental campaign. Construction of the TPC provided opportunities for the scientists to develop new designs for the light-weight and thin-walled field cage for the large pad plane and for the gating grid. Two PhD students (1 US and 1 Korea) graduated in 2016 based on their research on the TPC. At least four more doctoral theses (2 US, 1 Japan and 1 Korea) based on physics from the SπRIT experiments are expected.

Evaluation of chemical characteristics and correlation analysis with pulp browning of advanced selections of apples grown in Brazil

Directory of Open Access Journals (Sweden)

Luciana Ercoli

2017-02-01

Full Text Available In this research, the total phenolic content (TPC and antioxidant capacity (FRAP and DPPH•× assays of pulps and peels of advanced selection of apples grown in Brazil were investigated. The correlation analyses between the activity of polyphenoloxidase enzyme (PPO, vitamin C content, total titratable acidity, and color parameters were performed. The results indicated that the data differed significantly among the apple genotypes studied. The peels of the selection Epagri 170-91 and Epagri 170-25 showed the highest TPC and antioxidant capacities. In addition, the pulps of the Epagri 170-91 presented the highest TPC and antioxidant capacities, the lowest enzymatic browning, highest amount of vitamin C and lowest enzymatic activity when compared with other genotypes. The TPC and antioxidant capacities were significantly correlated in all genotypes analyzed. High correlation values between enzymatic browning and factors that affect the apple color were also found in all analyzed pulps, except between enzymatic browning and TPC. The results demonstrated that the enzymatic browning and TPC, as well as the antioxidant capacity and chemical characteristics, vary considerably depending on the apple genotypes and fruit tissues analyzed.

Study of Electromagnetic Interactions in the MicroBooNE Liquid Argon Time Projection Chamber

Energy Technology Data Exchange (ETDEWEB)

Caratelli, David [Columbia U.

2018-01-01

This thesis presents results on the study of electromagnetic (EM) activity in the MicroBooNE Liquid Argon Time Projection Chamber (LArTPC) neutrino detector. The LArTPC detector technology provides bubble-chamber like information on neutrino interaction final states, necessary to perform precision measurements of neutrino oscillation parameters. Accelerator-based oscillation experiments heavily rely on the appearance channel ! e to make such measurements. Identifying and reconstructing the energy of the outgoing electrons from such interactions is therefore crucial for their success. This work focuses on two sources of EM activity: Michel electrons in the 10-50 MeV energy range, and photons from 0 decay in the 30-300 MeV range. Studies of biases in the energy reconstruction measurement, and energy resolution are performed. The impact of shower topology at different energies is discussed, and the importance of thresholding and other reconstruction effects on producing an asymmetric and biased energy measurement are highlighted. This work further presents a study of the calorimetric separation of electrons and photons with a focus on the shower energy dependence of the separation power.

A Total Pleural Covering for Lymphangioleiomyomatosis Prevents Pneumothorax Recurrence.

Directory of Open Access Journals (Sweden)

Masatoshi Kurihara

Full Text Available Spontaneous pneumothorax is a major and frequently recurrent complication of lymphangioleiomyomatosis (LAM. Despite the customary use of pleurodesis to manage pnenumothorax, the recurrence rate remains high, and accompanying pleural adhesions cause serious bleeding during subsequent lung transplantation. Therefore, we have developed a technique of total pleural covering (TPC for LAM to wrap the entire visceral pleura with sheets of oxidized regenerated cellulose (ORC mesh, thereby reinforcing the affected visceral pleura and preventing recurrence.Since January 2003, TPC has been applied during video-assisted thoracoscopic surgery for the treatment of LAM. The medical records of LAM patients who had TPC since that time and until August 2014 are reviewed.TPC was performed in 43 LAM patients (54 hemithoraces, 11 of whom required TPC bilaterally. Pneumothorax recurred in 14 hemithoraces (25.9% from 11 patients (25.6% after TPC. Kaplan-Meier estimates of recurrence-free hemithorax were 80.8% at 2.5 years, 71.7% at 5 years, 71.7% at 7.5 years, and 61.4% at 9 years. The recurrence-free probability was significantly better when 10 or more sheets of ORC mesh were utilized for TPC (P = 0.0018. TPC significantly reduced the frequency of pneumothorax: 0.544 ± 0.606 episode/month (mean ± SD before TPC vs. 0.008 ± 0.019 after TPC (P<0.0001. Grade IIIa postoperative complications were found in 13 TPC surgeries (24.1%.TPC successfully prevented the recurrence of pneumothorax in LAM, was minimally invasive and rarely caused restrictive ventilatory impairment.

Antioxidant and DNA damage protective properties of anthocyanin-rich extracts from Hibiscus and Ocimum: a comparative study.

Science.gov (United States)

Sarkar, Biswatrish; Kumar, Dhananjay; Sasmal, Dinakar; Mukhopadhyay, Kunal

2014-01-01

Anthocyanin extracts (AEs) from Ocimum tenuiflorum (leaf), Hibiscus rosa-sinensis (petal) and Hibiscus sabdariffa (calyx) were investigated and compared for in vitro antioxidant activity and DNA damage protective property. Total phenolic content (TPC) and total anthocyanin content (TAC) of the AEs were determined and the major anthocyanins were characterised. In vitro antioxidant activities were assessed by ferric-reducing antioxidant power (FRAP) assay, 2,2-diphenyl-1-picryl hydrazyl (DPPH) radical-scavenging activity, 2-deoxy-D-ribose degradation assay and lipid peroxidation assay. The protective property of the AEs was also examined against oxidative DNA damage by H2O2 and UV using pUC19 plasmid. All the AEs particularly those from O. tenuiflorum demonstrated efficient antioxidant activity and protected DNA from damage. Strong correlation between antioxidant capacity and TPC and TAC was observed. Significant correlation between antioxidant capacity and TPC and TAC ascertained that phenolics and anthocyanins were the major contributors of antioxidant activity.

Novel Front-end Electronics for Time Projection Chamber Detectors

CERN Document Server

García García, Eduardo José

This work has been carried out in the European Organization for Nuclear Research (CERN) and it was supported by the European Union as part of the research and development towards the European detector the (EUDET) project, specifically for the International Linear Collider (ILC). In particle physics there are several different categories of particle detectors. The presented design is focused on a particular kind of tracking detector called Time Projection Chamber (TPC). The TPC provides a three dimensional image of electrically charged particles crossing a gaseous volume. The thesis includes a study of the requirements for future TPC detectors summarizing the parameters that the front-end readout electronics must fulfill. In addition, these requirements are compared with respect to the readouts used in existing TPC detectors. It is concluded that none of the existing front-end readout designs fulfill the stringent requirements. The main requirements for future TPC detectors are high integration, an increased n...

Optimisation of Ultrasound-Assisted Extraction Conditions for Phenolic Content and Antioxidant Capacity from Euphorbia tirucalli Using Response Surface Methodology

Science.gov (United States)

Vuong, Quan V.; Goldsmith, Chloe D.; Dang, Trung Thanh; Nguyen, Van Tang; Bhuyan, Deep Jyoti; Sadeqzadeh, Elham; Scarlett, Christopher J.; Bowyer, Michael C.

2014-01-01

Euphorbia tirucalli (E. tirucalli) is now widely distributed around the world and is well known as a source of traditional medicine in many countries. This study aimed to utilise response surface methodology (RSM) to optimise ultrasonic-assisted extraction (UAE) conditions for total phenolic compounds (TPC) and antioxidant capacity from E. tirucalli leaf. The results showed that ultrasonic temperature, time and power effected TPC and antioxidant capacity; however, the effects varied. Ultrasonic power had the strongest influence on TPC; whereas ultrasonic temperature had the greatest impact on antioxidant capacity. Ultrasonic time had the least impact on both TPC and antioxidant capacity. The optimum UAE conditions were determined to be 50 °C, 90 min. and 200 W. Under these conditions, the E. tirucalli leaf extract yielded 2.93 mg GAE/g FW of TPC and exhibited potent antioxidant capacity. These conditions can be utilised for further isolation and purification of phenolic compounds from E. tirucalli leaf. PMID:26785074

Experimental characterisation of recycled (glass/tpu woven fabric) flake reinforced thermoplastic composites

NARCIS (Netherlands)

Abdul Rasheed, Mohammed Iqbal; Rietman, Bert; Visser, Roy; Akkerman, Remko; Hoa, S.V.; Hubert, P.

2013-01-01

Recycling of continuously reinforced thermoplastic composites (TPC) has a substantial prospect at present and in future due to its increasing availability and rapidly growing application regime. This study focusses on the first steps in using TPC process scrap on a scale in which its maximum

Effect of brewing conditions on antioxidant properties of rosehip tea beverage: study by response surface methodology.

Science.gov (United States)

İlyasoğlu, Huri; Arpa, Tuba Eda

2017-10-01

The aim of this study was to investigate the effects of brewing conditions (infusion time and temperature) on the antioxidant properties of rosehip tea beverage. The ascorbic acid content, total phenolic content (TPC), and ferric reducing antioxidant power (FRAP) of rosehip tea beverage were analysed. A two-factor and three-level central composite design was applied to evaluate the effects of the variables on the responses. The best quadratic models were obtained for all responses. The generated models were validated under the optimal conditions. At the optimal conditions, the rosehip tea beverage had 3.15 mg 100 mL -1 of ascorbic acid, 61.44 mg 100 mL -1 of TPC, and 2591 µmol of FRAP. The best brewing conditions for the rosehip tea beverage were found to be an infusion time of 6-8 min at temperatures of 84-86 °C.

Possible physics program with a large acceptance hyperon spectrometer at J-PARC

International Nuclear Information System (INIS)

Imai, Kenichi

2013-01-01

We are going to construct a large acceptance hyperon spectrometer (HypTPC) at J-PARC primarily to search for H-dibaryon. The HypTPC consists of a superconducting Helmholtz magnet and a Time Projection Chamber (TPC). The short-life hyperons can be detected with high precision as well as any charged particles. Here, we discuss possible physics programs other than H-dibaryon which can be done with this spectrometer, such as a nucleon resonance spectroscopy experiment, systematic study of Λ(1405) and spectroscopy of Ξ and Ω - resonances. (author)

Two pore channel 2 differentially modulates neural differentiation of mouse embryonic stem cells.

Directory of Open Access Journals (Sweden)

Zhe-Hao Zhang

Full Text Available Nicotinic acid adenine dinucleotide phosphate (NAADP is an endogenous Ca(2+ mobilizing nucleotide presented in various species. NAADP mobilizes Ca(2+ from acidic organelles through two pore channel 2 (TPC2 in many cell types and it has been previously shown that NAADP can potently induce neuronal differentiation in PC12 cells. Here we examined the role of TPC2 signaling in the neural differentiation of mouse embryonic stem (ES cells. We found that the expression of TPC2 was markedly decreased during the initial ES cell entry into neural progenitors, and the levels of TPC2 gradually rebounded during the late stages of neurogenesis. Correspondingly, TPC2 knockdown accelerated mouse ES cell differentiation into neural progenitors but inhibited these neural progenitors from committing to neurons. Overexpression of TPC2, on the other hand, inhibited mouse ES cell from entering the early neural lineage. Interestingly, TPC2 knockdown had no effect on the differentiation of astrocytes and oligodendrocytes of mouse ES cells. Taken together, our data indicate that TPC2 signaling plays a temporal and differential role in modulating the neural lineage entry of mouse ES cells, in that TPC2 signaling inhibits ES cell entry to early neural progenitors, but is required for late neuronal differentiation.

A Total Pleural Covering for Lymphangioleiomyomatosis Prevents Pneumothorax Recurrence

Science.gov (United States)

Kurihara, Masatoshi; Mizobuchi, Teruaki; Kataoka, Hideyuki; Sato, Teruhiko; Kumasaka, Toshio; Ebana, Hiroki; Yamanaka, Sumitaka; Endo, Reina; Miyahashira, Sumika; Shinya, Noriko; Seyama, Kuniaki

2016-01-01

Background Spontaneous pneumothorax is a major and frequently recurrent complication of lymphangioleiomyomatosis (LAM). Despite the customary use of pleurodesis to manage pnenumothorax, the recurrence rate remains high, and accompanying pleural adhesions cause serious bleeding during subsequent lung transplantation. Therefore, we have developed a technique of total pleural covering (TPC) for LAM to wrap the entire visceral pleura with sheets of oxidized regenerated cellulose (ORC) mesh, thereby reinforcing the affected visceral pleura and preventing recurrence. Methods Since January 2003, TPC has been applied during video-assisted thoracoscopic surgery for the treatment of LAM. The medical records of LAM patients who had TPC since that time and until August 2014 are reviewed. Results TPC was performed in 43 LAM patients (54 hemithoraces), 11 of whom required TPC bilaterally. Pneumothorax recurred in 14 hemithoraces (25.9%) from 11 patients (25.6%) after TPC. Kaplan-Meier estimates of recurrence-free hemithorax were 80.8% at 2.5 years, 71.7% at 5 years, 71.7% at 7.5 years, and 61.4% at 9 years. The recurrence-free probability was significantly better when 10 or more sheets of ORC mesh were utilized for TPC (P = 0.0018). TPC significantly reduced the frequency of pneumothorax: 0.544 ± 0.606 episode/month (mean ± SD) before TPC vs. 0.008 ± 0.019 after TPC (Ppneumothorax in LAM, was minimally invasive and rarely caused restrictive ventilatory impairment. PMID:27658250

Factors Affecting Students' Acceptance of Tablet PCs: A Study in Italian High Schools

Science.gov (United States)

Cacciamani, Stefano; Villani, Daniela; Bonanomi, Andrea; Carissoli, Claudia; Olivari, Maria Giulia; Morganti, Laura; Riva, Giuseppe; Confalonieri, Emanuela

2018-01-01

To maximize the advantages of the tablet personal computer (TPC) at school, this technology needs to be accepted by students as new tool for learning. With reference to the Technology Acceptance Model and the Unified Theory of Acceptance and Use of Technology, the aims of this study were (a) to analyze factors influencing high school students'…

A study of small leaks of water into sodium-heated steam generators - self evolution and wastage

International Nuclear Information System (INIS)

Feburie, V.; Desmas, T.; Cronier, B.

1987-01-01

MICROMEGAS is a fully automatic test loop operating without human surveillance. It is utilized to study small leaks of water into sodium, specially the spontaneous development of a fatigue-induced crack in a tube of Incoloy 800 (dormant period, microleak, self-evolution) and the wastage of neighbouring tubes. The thermohydraulic conditions of the last tests corresponded to the economizer zone of SUPER-PHENIX steam generators, at 350 0 C. These tests were compared with those which had been done before, corresponding to the superheating zone, at 490 0 C. The main result was that the microleak phase was longer and the self-evolution slower at 350 0 C than at 490 0 C. (author)

Comparative study on conventional, ultrasonication and microwave assisted extraction of γ-oryzanol from rice bran.

Science.gov (United States)

Kumar, Pramod; Yadav, Devbrat; Kumar, Pradyuman; Panesar, Paramjeet Singh; Bunkar, Durga Shankar; Mishra, Diwaker; Chopra, H K

2016-04-01

In present study, conventional, ultrasonic and microwave assisted extraction methods were compared with the aim of optimizing best fitting solvent and method, solvent concentration and digestion time for high yield of γ-oryzanol from rice bran. Petroleum ether, hexane and methanol were used to prepare extracts. Extraction yield were evaluated for giving high crude oil yield, total phenolic content (TPC) and γ-oryzanol content. Gas chromatography-mass spectrophotometry was used for the determination of γ-oryzanol concentration. The highest concentration of γ-oryzanol was detected in methanolic extracts of microwave treatment (85.0 ppm) followed by ultrasonication (82.0 ppm) and conventional extraction method (73.5 ppm). Concentration of γ-oryzanol present in the extracts was found to be directly proportional to the total phenolic content. A combination of 80 % methanolic concentration and 55 minutes digestion time of microwave treatment yielded the best extraction method for TPC and thus γ-oryzanol (105 ppm).

Effect of contaminant concentration on in situ bacterial sulfate reduction and methanogenesis in phenol-contaminated groundwater

International Nuclear Information System (INIS)

Baker, Kieran M.; Bottrell, Simon H.; Thornton, Steven F.; Peel, Kate E.; Spence, Michael J.

2012-01-01

The availability of dissolved O 2 can limit biodegradation of organic compounds in aquifers. Where O 2 is depleted, biodegradation proceeds via anaerobic processes, including NO 3 -, Mn(IV)-, Fe(III)- and SO 4 -reduction and fermentation/methanogenesis. The environmental controls on these anaerobic processes must be understood to support implementation of management strategies such as monitored natural attenuation (MNA). In this study stable isotope analysis is used to show that the relative significance of two key anaerobic biodegradation processes (bacterial SO 4 reduction (BSR) and methanogenesis) in a phenol-contaminated sandstone aquifer is sensitive to spatial and temporal changes in total dissolved phenols concentration (TPC) (= phenol + cresols + dimethylphenols) over a 5-a period. In general, 34 SO 4 -enrichment (characteristic of bacterial SO 4 reduction) is restricted spatially to locations where TPC −1 . In contrast, 13 C-depleted CH 4 and 13 C-enriched CO 2 isotope compositions (characteristic of methanogenesis) were measured at TPC up to 8000 mg L −1 . This is consistent with previous studies that demonstrate suppression of BSR at TPC of >500 mg L −1 , and suggests that methanogenic microorganisms may have a higher tolerance for TPC in this contaminant plume. It is concluded that isotopic enrichment trends can be used to identify conditions under which in situ biodegradation may be limited by the properties of the biodegradation substrate (in this case TPC). Such data may be used to deduce the performance of MNA for contaminated groundwater in similar settings.

Drift velocity studies at a time projection chamber for various water contents in the gas mixture

International Nuclear Information System (INIS)

Stoever, F.W.

2007-03-01

For the answer of different open questions in high energy physics the construction of a linear e + e - collider with a c. m. energy of up to one TeV is prepared. With this is connected a comprehensive development on detectors, which must satisfy the requirements of the planned experiments. For the track chamber a TPC is considered. Hereby it deals with a gas-based concept, which has already been proved in past experiments and which is at time further developed by means of test chambers. The composition of the gas mixtureplays hereby an important role. Impurities of the gas mixture, especially by oxygen and water from the ambient air are a fact, which occurs every time in the development phase and can scarcely be avoided. From this arose the motivation to study directly the effects of this impurities. The object of the present thesis are correlations between drift velocity and water content in the chamber gas of a TPC

Analysis of data recorded by the LCTPC equipped with a two layer GEM-system

CERN Document Server

Ljunggren, M

2012-01-01

wire based readout. The prototype TPC is placed in a 1 Tesla magnet at DESY and tested using an electron beam. Analyses of data taken during two different measurement series, in 2009 and 2010, are presented here. The TPC was instrumented with a two layer GEM system and read out using modified electronics from the ALICE experiment, including the programmable charge sensitive preamp-shaper PCA16. The PCA16 chip has a number of programmable parameters which allows studies to determine the settings optimal to the final TPC. Here, the impact of the shaping time on the space resolution in the drift direction was studied. It was found that a shaping time of 60 ns is the b...

Measurement of magnetic and electric field inhomogenities in a time projection chamber using laser tracks

International Nuclear Information System (INIS)

Benetta, M.; Froberger, J.P.; Lehraus, I.; Mathewson, R.; May, J.; Price, M.; Schlater, D.; Tejessi, W.; Witzeling, W.

1985-01-01

The large time projection chambers (TPC) for particle track measurements have their electric drift field parallel to the magnetic field which is needed for the momentum measurement of the particles. Small field inhomogeneities of the order of epsilon times the main field cause large track distortions (coordinate displacements) of the order of epsilon times the driftlength. It is therefore important for every TPC to know the inhomogeneities very well. Laser rays have proven to be useful to study them. We report here on our experience with a TPC having a maximum drift length of 1.3 m

Changing the model of care delivery: nurses' perceptions of job satisfaction and care effectiveness.

Science.gov (United States)

Wells, Judith; Manuel, Madonna; Cunning, Glenda

2011-09-01

To examine nurses' perceptions of job satisfaction, empowerment, and care effectiveness following a change from team to a modified total patient care (TPC) delivery model. Empirical data related to TPC is limited and inconclusive. Similarly, evidence demonstrating nurses' experience with change and restructuring is limited. A mixed method, longitudinal, descriptive design was used. Registered nurses and licenced practical nurses in two acute-care nursing units completed quantitative and qualitative surveys. Lewin's change theory provided the framework for the study. No significant change in job satisfaction was observed; however, it was less than optimal at all three time-periods. Nurses were committed to their jobs but relatively dissatisfied with their input into the goals and processes of the organization. Client care was perceived to be more effective under TPC. Job satisfaction remained consistent following the transition to TPC. However, nurses perceived that client care within the modified TPC model was more effective than in the previous model. Nursing administration must work collaboratively with nurses to improve processes in nursing practice that could enhance nurses' job satisfaction and improve client care delivery. 2011 Blackwell Publishing Ltd.

An Optimised Aqueous Extract of Phenolic Compounds from Bitter Melon with High Antioxidant Capacity

Directory of Open Access Journals (Sweden)

Sing Pei Tan

2014-12-01

Full Text Available Bitter melon (Momordica charantia L. is a tropical fruit claimed to have medicinal properties associated with its content of phenolic compounds (TPC. The aim of the study was to compare water with several organic solvents (acetone, butanol, methanol and 80% ethanol for its efficiency at extracting the TPC from freeze-dried bitter melon powder. The TPC of the extracts was measured using the Folin-Ciocalteu reagent and their antioxidant capacity (AC was evaluated using three assays. Before optimisation, the TPC and AC of the aqueous extract were 63% and 20% lower, respectively, than for the best organic solvent, 80% ethanol. However, after optimising for temperature (80 °C, time (5 min, water-to-powder ratio (40:1 mL/g, particle size (1 mm and the number of extractions of the same sample (1×, the TPC and the AC of the aqueous extract were equal or higher than for 80% ethanol. Furthermore, less solvent (40 mL water/g and less time (5 min were needed than was used for the 80% ethanol extract (100 mL/g for 1 h. Therefore, this study provides evidence to recommend the use of water as the solvent of choice for the extraction of the phenolic compounds and their associated antioxidant activities from bitter melon.

Antioxidant potential of brans of twenty-nine red and white rice (Oryza sativa L. varieties of Sri Lanka

Directory of Open Access Journals (Sweden)

Walimuni Kanchana Subhashini Mendis Abeysekera

2017-11-01

Full Text Available Objective: To evaluate antioxidant properties of brans of twenty-nine red and white rice varieties of Sri Lanka. Methods: Brans of 21 new improved (NI, 2 old improved (OI and 6 traditional red and white rice varieties of Sri Lanka were studied for range of antioxidant properties. The studied antioxidant properties included total polyphenolic content (TPC, ferric reducing antioxidant power (FRAP, oxygen radical absorbance capacity (ORAC, 2,2’-azino-bis(3- ethylbenzothiazoline-6-sulfonic acid (ABTS radical scavenging activity and 1,1-diphenyl- 2-picrylhydrazine (DPPH radical scavenging activity in vitro. Bran of black rice variety from Korea was also studied for the same antioxidant properties for comparison. Results: Results exhibited significantly high ABTS and DPPH radical scavenging activities and 10, 7 and 2.5 fold greater TPC, FRAP and ORAC activities in brans of red rices (BRRs compared to brans of white rices irrespective of NI, OI and traditional rice types. Among BRRs traditional varieties had greater ABTS and DPPH radical scavenging activities and 1.7, 1.3 and 1.2 fold respectively greater TPC, FRAP and ORAC in contrast to NI red rices. Traditional red rice varieties, Kalu Heeneti (TPC and ORAC, Pachchaperumal (TPC and DPPH and Kurulu Thuda (DPPH and OI red rice variety H4 (FRAP exhibited the highest activities for the antioxidant properties studied. Further, these varieties had significantly high activities compared to black rice. Conclusions: In conclusion, BRRs especially traditional red rices had greater antioxidant properties and consumption may be useful in managing various chronic diseases.

Assessment of proactive transmission power control for wireless sensor networks

NARCIS (Netherlands)

kotian, Roshan; Exarchakos, Georgios; Liotta, Antonio

2014-01-01

In order to prolong lifetime of Wireless Sensor Networks (WSN), Transmission Power Control (TPC) techniques are employed. The existing TPC schemes adjust the transmission power mostly reacting to changes at link quality between communicating nodes. Proactive TPC has been proposed in the recent past

Prototype board development for the validation of the VMM ASICs for the New Small Wheel ATLAS upgrade project

CERN Document Server

Gkountoumis, Panagiotis; The ATLAS collaboration

2018-01-01

The VMM is a custom Application Specific Integrated Circuit (ASIC) which was designed to be used in the frontend readout electronics of both micromegas (MM) and small Thin Gap Chambers (sTGC) detectors of the New Small Wheel (NSW) Phase-I upgrade project of the ATLAS experiment. A new version of the VMM was recently fabricated and for that reason various prototype boards, the micromegas Front-End (MMFE1) and the General Purpose VMM (GPVMM), have been fabricated and extensively tested in order to validate the functionality of the ASIC. These boards use commercial Field Programmable Gate Arrays (FPGAs) for direct communication with computers which is achieved through 10=100=1000 Mbps Ethernet and UDP/IP protocols. The low noise performance of these boards gave the opportunity to be used in various test beams with micormegas detectors for validating the VMM and for performance studies of the sTGC detectors. A detailed description of the boards along with the results of the test beam and the detector studies will...

Gait-Cycle-Driven Transmission Power Control Scheme for a Wireless Body Area Network.

Science.gov (United States)

Zang, Weilin; Li, Ye

2018-05-01

In a wireless body area network (WBAN), walking movements can result in rapid channel fluctuations, which severely degrade the performance of transmission power control (TPC) schemes. On the other hand, these channel fluctuations are often periodic and are time-synchronized with the user's gait cycle, since they are all driven from the walking movements. In this paper, we propose a novel gait-cycle-driven transmission power control (G-TPC) for a WBAN. The proposed G-TPC scheme reinforces the existing TPC scheme by exploiting the periodic channel fluctuation in the walking scenario. In the proposed scheme, the user's gait cycle information acquired by an accelerometer is used as beacons for arranging the transmissions at the time points with the ideal channel state. The specific transmission power is then determined by using received signal strength indication (RSSI). An experiment was conducted to evaluate the energy efficiency and reliability of the proposed G-TPC based on a CC2420 platform. The results reveal that compared to the original RSSI/link-quality-indication-based TPC, G-TPC reduces energy consumption by 25% on the sensor node and reduce the packet loss rate by 65%.

Ultrasound assisted extraction of polyphenols and their distribution in whole mung bean, hull and cotyledon.

Science.gov (United States)

Singh, Barinderjit; Singh, Narpinder; Thakur, Sheetal; Kaur, Amritpal

2017-03-01

In this study, extraction of polyphenols using different solvents (acetone, ethanol, methanol and water) with ultrasound and conventional method from whole mung bean (WMB), hull and cotyledon was conducted. Total phenolic content (TPC), total flavonoids content (TFC), total antioxidant activities (TAA), ferric reducing power (FRP) and DPPH radical scavenging activity were determined. Ultrasound treated extracts exhibited higher TPC, TFC, TAA, FRP and DPPH in different mung bean fractions than CSE. Among the solvents, acetone showed better TPC, TFC, TAA, FRP and DPPH. Hull had significantly higher TPC, TFC, TAA, FRP and DPPH than WMB and cotyledon. Sinapic acid (SA) was the major polyphenol in different fractions. Acetone extract of hull showed high polyphenol content. SA, ferulic acid, catechin, p-coumaric acid, resveratrol, quercetin and luteolin were the major contributors to antioxidant activity of acetone extract. Mung bean hull contained the maximum polyphenols and acetone was observed to be the best extraction medium for polyphenols in combination with ultrasound.

Hypoglycemic effect of basil (Ocimum basilicum) aqueous extract is mediated through inhibition of α-glucosidase and α-amylase activities: an in vitro study.

Science.gov (United States)

El-Beshbishy, Ha; Bahashwan, Sa

2012-02-01

The present study investigated the in vitro hypoglycemic activity of basil (Ocimum basilicum) aqueous extract. Preliminary phytochemical screening of the extract revealed the presence of reducing sugars, cardiac glycosides, tannins, saponins, glycosides, flavonoids and steroids. The total polyphenols content (TPC), flavonoids content (FC), percentage diphenylpicrylhydrazyl (DPPH( · )) radical inhibition and total antioxidant status (TAS) were estimated. The FC was 41 ± 2.2 rutin/g dry extract, the TPC was 146 ± 5.26 mg catechin/g dry extract and the TAS was 5.12 ± 0.7 mmol/L. The %DPPH( · ) free radical inhibition was 60%, 54%, 49% and 43%, respectively, for different extract concentrations; 20, 18.2, 16.3 and 14.5 mg/ml, respectively. The extract elicited significant dose-dependent pattern against rat intestinal sucrase (RIS; IC(50) = 36.72 mg/ml), rat intestinal maltase (RIM; IC(50) = 21.31 mg/ml) and porcine pancreatic α-amylase (PPA; IC(50) = 42.50 mg/ml) inhibitory activities. The inhibition was greater against maltase compared with sucrase. These effects may be attributed to the high TPC and FC levels. The linear regression analysis revealed strong significant positive correlations between %DPPH( · ) radical inhibition and each of %RIS, %RIM and %PPA inhibiting activity. Also, strong significant positive correlations between %RIS and either %RIM or %PPA inhibition activity were observed. We concluded therefore that basil aqueous extract via antioxidant and possibly α-glucosidase and α-amylase inhibiting activities, offered positive benefits to control diabetes.

Dose-Response Effect of Tualang Honey on Postprandial Antioxidant Activity and Oxidative Stress in Female Athletes: A Pilot Study.

Science.gov (United States)

Ahmad, Nur Syamsina; Abdul Aziz, Azlina; Kong, Kin Weng; Hamid, Mohamad Shariff A; Cheong, Jadeera Phaik Geok; Hamzah, Sareena Hanim

2017-12-01

Tualang honey (TH) contains antioxidants such as ascorbic acid, phenolic acids, and flavonoids that may be protective against oxidative stress of exercise. The aim of this study was to examine the postprandial antioxidant activity and oxidative stress after ingestion of high and low dosages of TH in female athletes. Twenty female athletes (aged 21.3 [2.1] years; body weight [BW] 54.1 [5.7] kg) were randomly assigned into two groups and consumed either 1.5 g/kg BW TH (high honey; HH; n = 10) or 0.75 g/kg BW TH (low honey; LH; n = 10). Blood sample was collected at fasting and at 0.5, 1, 2, and 3 h after TH consumption. Plasma was analyzed for total phenolic content (TPC), antioxidant activity (ferric reducing antioxidant power [FRAP]), and oxidative stress biomarkers (malondialdehyde [MDA] and reactive oxygen species [ROS]). The 3-h area under the curve (AUC) for MDA was significantly lower in the LH group compared with HH group, suggesting less oxidative stress in the LH group. However, the AUCs for TPC, FRAP, and ROS were not affected by the dosages. The concentrations of TPC and FRAP increased from baseline to 2 and 1 h after TH consumption, respectively, and concentrations returned toward baseline at 3 h in both LH and HH groups. MDA concentration significantly decreased (p antioxidant activity and suppressing oxidative stress in female athletes. The time-course effect of TH that provides optimal antioxidant activity and oxidative stress protection was between 1 and 2 h after its consumption.

The Development of Micro-Pattern Gas Detectors

CERN Document Server

BALOUZA, Samah

2014-01-01

This work is aimed to study the electron transparency in 3-D woven mesh that is used in micromegas detector. The importance of calculating the transparency is because it is enter in the gain calibration of the detector. The simulation tool is COMSOL Multiphysics in which it is solved the differential equations by Finite Element Method.

A Comparative Study on Formation of Polar Components, Fatty Acids and Sterols during Frying of Refined Olive Pomace Oil Pure and Its Blend Coconut Oil.

Science.gov (United States)

Ben Hammouda, Ibtissem; Triki, Mehdi; Matthäus, Bertrand; Bouaziz, Mohamed

2018-04-04

The frying performance of pure refined olive-pomace oil (ROPO) and blended with refined coconut oil (RCO) (80:20) was compared during a frying operation of French fries at 180 °C. Blending polyunsaturated oils with highly saturated or monounsaturated oils has been studied extensively, however in literature there is no study has been reported so far on blending ROPO (rich in monounsaturated fatty acids) with RCO (rich in saturated fatty acids) to formulate new frying oils. At the end of the frying process, the blend of ROPO/RCO exhibited a higher chemical stability than the pure ROPO based on total polar compounds (TPC), and polymers. The rate of TPC formation was achieved 23.3% and 30.6% for the blend and the pure oil, respectively. Trans and free fatty acids content, as well as anisidine value were also observed to be the highest in the pure ROPO. This study evaluated the frying performance in the search for appropriate frying oils to deliver healthy fried products with optimized nutritional qualities.

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.

Effect of water cooking on antioxidant capacity of carotenoid-rich vegetables in Taiwan

Directory of Open Access Journals (Sweden)

Fuh-Juin Kao

2014-06-01

Full Text Available Carotenoid-rich green leafy vegetables including cilantro, Thai basil leaves, sweet potato leaves, and choy sum were selected to evaluate the effects of water cooking or boiling on their total carotenoid content (TCC, total phenolic content (TPC, and total antioxidant capacity (TAC. The percentage inhibition of peroxidation (%IP, Trolox equivalent antioxidant capacity (TEAC, and metal-chelating effect were used to evaluate TAC. The results indicated that TCC reached the maximum after boiling cilantro, Thai basil leaves, and sweet potato leaves for 10 minutes, 5 minutes, and 5 minutes, respectively, and choy sum remained almost unchanged after 30 minutes of boiling. Boiling cilantro and choy sum had a negative effect on their TPC, whereas there was a significant increase in TPC of Thai basil leaf and sweet potato leaf at 1 minute and 5 minutes of boiling, respectively. During water cooking, TAC of the vegetables did not demonstrate a consistent trend. However, TCC was a vital contributor to %IP, whereas TPC showed a strong association with TEAC. Our findings suggest that a boiling time of ≤5 minutes would be better for preserving or enhancing TCC and TPC as well as revealing a higher %IP, TEAC, or metal-chelating effect for the four vegetables investigated in this study.

Optimization of extraction of phenolic content from conyza bonariensis

International Nuclear Information System (INIS)

Thabit, R.A.S.; Cheng, X.R.

2014-01-01

This study aims to find out the effects of solvent type (ethanol, water, and ionic liquid (1-butyl-3-methylimidazolium bromide)(BMIM)Br), time (30-90min), and microwave power (200 - 600w) on extraction rate, antioxidant activity, and total phenolic content (TPC) of Conyza bonariensis. The functional components from C. bonariensis were extracted using high efficient microwave-assisted extraction technology. The experiments were carried out according to 17 runs with 3 variables and three levels for the optimization in response surface methodology (RSM) system. The extracts were analyzed by spectrophotometeric methods for the antioxidant and TPC. The optimal conditions for extraction rate, antioxidant and TPC were determined by RSM. The Box Behnken design (BBD) showed the polynomial. The optimal conditions, including (BMIM)Br as the solvent with 45.47 min and 300.60 w power, lead to the best extraction rate (25.94%), maximum DPPH radical scavenging (95.90%) and maximum TPC (174.18 mg GAE/g). Under these conditions, the experimental extraction rate was 25.13 ± 0.85 %, DPPH radical scavenging was 93.8 ± 1.67% and TPC was 171.5 ± 1.06mg GAE/g of the C. bonariensis extract, which matched with the predicted values. (author)

Determination of flavonoids, polyphenols and antioxidant activity of Tephrosia purpurea: a seasonal study.

Science.gov (United States)

Pandey, Madan Mohan; Khatoon, Sayyada; Rastogi, Subha; Rawat, Ajay Kumar Singh

2016-11-01

Tephrosia purpurea (Linn · ) Pers. is widely used in traditional medicine to treat liver disorders, febrile attacks, enlargement and obstruction of liver, spleen, and kidney. In the present study, investigations were carried out to determine the seasonal impact on the content of flavonoid glycosides and on antioxidant activities so as to identify the optimal time of harvesting. The plant materials were collected in different seasons during 2013-2014. Air-dried, powdered plant materials were extracted with 95% ethanol and ethanol: water (1:1) by ultrasound-assisted extraction process. Their chemical composition in terms of total polyphenol and flavonoid contents (TPCs and TFCs) was determined using modified colorimetric Folin-Ciocalteu method and aluminum chloride colorimetric assay respectively. To determine the in vitro antioxidant activity, diphenyl-picryl hydrazyl (DPPH) radical-scavenging assay and total antioxidant capacity by phosphomolybdate antioxidant assay were carried out. High-performance liquid chromatography (HPLC)/photo-diode array (PDA) analysis was used to quantify the flavonoid glycosides in the samples collected in different seasons. Correlation studies were also carried out between antioxidant activities and TPCs. The highest TPC and TFC were found to be in the 95% ethanolic extract of the August sample and the lowest in the 50% hydro-alcoholic extract of the plant sample collected in winter season. It was observed that in both the assays used to determine the antioxidant activity, the 95% ethanolic extracts in all the seasons showed a higher activity than their respective 50% hydro-alcoholic extracts with an increase in activity as we go from cold to hot to rainy seasons. Based on correlation analysis, DPPH radical-scavenging activities as well as the spectrophotometrically measured phosphomolybdenum complex were also strongly correlated with TPC of the extracts. The most abundant flavonoid glycoside was quercetin-3-O-rhamnoglucoside in all

A comparison of basal and eye-flush tears for the analysis of cat tear proteins.

Science.gov (United States)

Petznick, Andrea; Evans, Margaret D M; Madigan, Michele C; Markoulli, Maria; Garrett, Qian; Sweeney, Deborah F

2011-02-01

To identify a rapid and effective tear collection method providing sufficient tear volume and total protein content (TPC) for analysis of individual proteins in cats. Domestic adult short-haired cats (12-37 months; 2.7-6.6 kg) were used in the study. Basal tears without stimulation and eye-flush tears after instillation of saline (10 μl) were collected using microcapillary tubes from animal eyes either unwounded control or wounded with 9-mm central epithelial debridement giving four groups with n = 3. Tear comparisons were based on total time and rate for tear collection, TPC using micro bicinchoninic acid (BCA), tear immunoglobulin A (IgA), total matrix-metalloproteinase (MMP)-9 concentration using sandwich enzyme-linked immunosorbent assay (ELISA) and MMP-9 activity. Eye-flush tears were collected significantly faster than basal tears in wounded eyes with higher rates for tear collection in unwounded control and wounded eyes. TPC was significantly lower in eye-flush tears compared to basal tears. The relative proportion of tear IgA normalized to TPC (% IgA of TPC) was not significantly different between basal and eye-flush tears. In unwounded control eyes, MMP-9 was slightly higher in eye-flush than in basal tears; activity of MMP-9 in both tear types was similar. In wounded eyes, eye-flush tears showed highest MMP-9 levels and activity on Day 1, which subsequently decreased to Day 7. MMP-9 activity in basal tears from wounded eyes did not display changes in expression. Eye-flush tears can be collected rapidly providing sufficient tear volume and TPC. This study also indicates that eye-flush tears may be more suitable than basal tears for the analysis of MMPs following corneal wounding. © 2011 The Authors. Acta Ophthalmologica © 2011 Acta Ophthalmologica Scandinavica Foundation.

[Quality evaluation and antioxidant activity research of Schisandra chinensis from various habitats].

Science.gov (United States)

Han, Zhi-Fu; Hu, Gao-Sheng; Li, Na; Fan, Xing; Jia, Jing-Ming

2012-12-01

To determine the contents of lignans, crude polysaccharides (CP) and total phenolic compounds (TPC) of Schisandra chinensis from various habitats in Liaoning province and evaluate their quality and free radical scavenging (FRS) activity. Contents of schisandrol, deoxyschizandrin and schisandrin B were determined by RP-HPLC. Contents of TPC, CP and FRS activity were determined by Folin-Cicalteu's, phenol-sulfuric acid and DPPH x method, respectively. Sample from Liaoyang city had the highest contents of lignans (21.75 mg/g); Sample from Shenbei New district of Shenyang city had the highest contents of CP (88.72 mg/g); Sample from Guanmenshan district of Benxi city had the highest contents of TPC and FRS activity (26.06 mg/g and 86.3%, respectively). Linear regression analysis results showed that contents of TPC had higher correlation coefficient with FRS activity than that of lignans. Their linear regression equations were Y = 1.3677X + 46.97, R2 = 0.6869 and Y = 2.5916X + 57.927, R2 = 0.1747 for TPC and lignans with FRS activity, respectively. The contents of lignans, CP and TPC are significantly different from samples collected from various habitats in Liaoning province. The main antioxidative substances are TPC, and lignans have no significant correlation with FRS activity.

Trabalho de casa, auto-eficácia e rendimento em matemática

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Pedro Sales Luís Rosário

Full Text Available O Trabalho de Casa (TPC é uma estratégia instrutiva amplamente utilizada na Escola de muitos países. O TPC é um processo complexo que é afectado por múltiplos factores de ordem cognitiva, motivacional, social e contextual. A investigação tem-se centrado no tempo despendido na realização das tarefas de TPC, no entanto os resultados de vários estudos e as críticas metodológicas sugerem a necessidade de direccionar a pesquisa para outras variáveis. O objectivo deste estudo é a análise do poder preditivo da auto-eficácia percebida na Matemática e de três dimensões menos exploradas na literatura do TPC (e.g., número de TPC prescritos, taxa de completamento, e correcção percebida do TPC sobre o rendimento a matemática, em alunos portugueses do 5.º e 6.º ano de escolaridade (10 e 11 anos. Os resultados sugerem que o rendimento a matemática se encontra explicado, positiva e significativamente, pelas variáveis escolhidas. As conclusões sugerem a urgência de repensar o TPC como ferramenta educativa promotora do sucesso académico.

[Experiment studies of electron-positron interactions at the Stanford Linear Accelerator Center

International Nuclear Information System (INIS)

Hertzbach, S.S.; Kofler, R.R.

1993-01-01

The High Energy Physics group at the University of Massachusetts has continued its' program of experimental studies of electron-positron interactions at the Stanford Linear Accelerator Center (SLAC). The group activities have included: analysis of data taken between 1982 and 1990 with the TPC detector at the PEP facility, continuing data collection and data analysis using the SLC/SLD facility, planning for the newly approved B-factory at SLAC, and participation in design studies for future high energy linear colliders. This report will briefly summarize these activities

Exclusive Muon-Neutrino Charged Current Muon Plus Any Number of Protons Topologies In ArgoNeuT

Energy Technology Data Exchange (ETDEWEB)

Partyka, Kinga Anna [Yale Univ., New Haven, CT (United States)

2013-01-01

Neutrinos remain among the least understood fundamental particles even after decades of study. As we enter the precision era o f neutrino measurements bigger and more sophisticated detectors have emerged. The leading candidate among them is a Liquid Argon Time Projection Chamber (LArTPC ) detector technology due to its bubble-like chamber imaging, superb background rejection and scalability. I t is a perfect candidate that w ill aim to answer the remaining questions of the nature o f neutrino and perhaps our existence. Studying neutrinos with a detector that employs detection via beautiful images o f neutrino interactions can be both illuminating and surprising. The analysis presented here takes the full advantage of the LArTPC power by exploiting the first topological analysis of charged current muon neutrino p + N p , muon and any number of protons, interactions with the ArgoNeuT LArTPC experiment on an argon target. The results presented here are the first that address the proton multiplicity at the vertex and the proton kinematics. This study also addresses the importance o f nuclear effects in neutrino interactions. Furthermore, the developed here reconstruction techniques present a significant step forward for this technology and can be employed in the future LArTPC detectors.

An optical fiber-based flexible readout system for micro-pattern gas detectors

Science.gov (United States)

Li, C.; Feng, C. Q.; Zhu, D. Y.; Liu, S. B.; An, Q.

2018-04-01

This paper presents an optical fiber-based readout system that is intended to provide a general purpose multi-channel readout solution for various Micro-Pattern Gas Detectors (MPGDs). The proposed readout system is composed of several front-end cards (FECs) and a data collection module (DCM). The FEC exploits the capability of an existing 64-channel generic TPC readout ASIC chip, named AGET, to implement 256 channels readout. AGET offers FEC a large flexibility in gain range (4 options from 120 fC to 10 pC), peaking time (16 options from 50 ns to 1 us) and sampling freqency (100 MHz max.). The DCM contains multiple 1 Gbps optical fiber serial link interfaces that allow the system scaling up to 1536 channels with 6 FECs and 1 DCM. Further scaling up is possible through cascading of multiple DCMs, by configuring one DCM as a master while other DCMs in slave mode. This design offers a rapid readout solution for different application senario. Tests indicate that the nonlinearity of each channel is less than 1%, and the equivalent input noise charge is typically around 0.7 fC in RMS (root mean square), with a noise slope of about 0.01 fC/pF. The system level trigger rate limit is about 700 Hz in all channel readout mode. When in hit channel readout mode, supposing that typically 10 percent of channels are fired, trigger rate can go up to about 7 kHz. This system has been tested with Micromegas detector and GEM detector, confirming its capability in MPGD readout. Details of hardware and FPGA firmware design, as well as system performances, are described in the paper.

Relationship between total polar components and polycyclic aromatic hydrocarbons in fried edible oil.

Science.gov (United States)

An, Ke-Jing; Liu, Yu-Lan; Liu, Hai-Lan

2017-09-01

Deep-fried dough sticks (a Chinese traditional breakfast) were fried individually in peanut, sunflower, rapeseed, rice bran, soybean and palm oil without any time lag for 32 h (64 batches fried, each for 30 min) and fried oil samples were obtained every 2 h. The frying-induced changes in the levels of total polar compounds (TPC) and polycyclic aromatic hydrocarbons (PAHs) were investigated by edible oil polar compounds (EOPC) fast separation chromatographic system and gas chromatography-mass spectrometry (GC-MS), respectively. The correlations were analysed of TPC with benzo[a]pyrene (BaP), TPC and PAH4 (benzo[a]anthracene, chrysene, benzo[b]fluoranthene and benzo[a]pyrene) as well as TPC with PAH16 (USEPA 16 PAHs). The results revealed that the levels of TPC and PAHs in fried oil considerably increased with frying time, and the type of oil affected their formation, which could inform the choice of oil for frying. The total BaP equivalents (∑BaPeq) concentrations in fresh oil and in oil whose TPC exceeded 27% were 2.14-13.48 and 5.78-10.80 μg kg -1 , respectively, which means that the carcinogenic potency of frying oil was more pronounced than that of fresh oil. In addition, the TPC concentration was significantly correlated with the concentrations of the sum of the 16 PAHs, PAH4 and BaP, so that the levels of PAHs could be predicted according to the levels of TPC in fried oil. In European standards, the rejection point for TPC in frying oil should be recalculated when considered PAHs. In all, the concentration of PAHs is a vital factor for ensuring the safety of frying oil.

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.

Microbiological Studies of Semi-Preserved Natural Condiments Paste Stored in Refrigerator and Ambient Temperature

Science.gov (United States)

Dien, H. A.; Montolalu, R. I.; Mentang, F.; Mandang, A. S. K.; Rahmi, A. D.; Berhimpon, S.

2018-01-01

The aims of this studies were to prepare juice and raw condiment to be come semipreserve pastes, and to do microbial assessments on the both pastes during storing in refrigerator and ambient temperatures. For both pastes in refrigerator, samples were taken at 0, 2, 4, 5, 6, 8, 10, 15, 20, 25, and 30 days, and in ambient temperature samples were taken at 0, 1, 2, 3, 4, and 6 days. Assessment were done for TPC, total coliform and E. coli, Salmonella sp, Staphylococcus sp., Vibrio sp., pH and water content. The results shown that juice paste stored in refrigerator still good until 30 days (TPC 1,5x104 CFU/g), and in ambient temperature still good until 6 days (2x104 CFU/g). Condiment paste stored in refrigerator still good until 30 days (6.5x103 CFU/g), and in ambient temperature still good until 6 days (1.17x104 CFU/g). However, recommended that condiment paste stored in ambient temperature only until 4 days (7.3x103CFU/g), while that juice paste until 5 days (7.8x103CFU/g). There were no pathogenic bacteria found in all samples.

Variable Selection via Partial Correlation.

Science.gov (United States)

Li, Runze; Liu, Jingyuan; Lou, Lejia

2017-07-01

Partial correlation based variable selection method was proposed for normal linear regression models by Bühlmann, Kalisch and Maathuis (2010) as a comparable alternative method to regularization methods for variable selection. This paper addresses two important issues related to partial correlation based variable selection method: (a) whether this method is sensitive to normality assumption, and (b) whether this method is valid when the dimension of predictor increases in an exponential rate of the sample size. To address issue (a), we systematically study this method for elliptical linear regression models. Our finding indicates that the original proposal may lead to inferior performance when the marginal kurtosis of predictor is not close to that of normal distribution. Our simulation results further confirm this finding. To ensure the superior performance of partial correlation based variable selection procedure, we propose a thresholded partial correlation (TPC) approach to select significant variables in linear regression models. We establish the selection consistency of the TPC in the presence of ultrahigh dimensional predictors. Since the TPC procedure includes the original proposal as a special case, our theoretical results address the issue (b) directly. As a by-product, the sure screening property of the first step of TPC was obtained. The numerical examples also illustrate that the TPC is competitively comparable to the commonly-used regularization methods for variable selection.

The influence of ripening stage and cultivation system on the total antioxidant activity and total phenolic compounds of yellow passion fruit pulp.

Science.gov (United States)

Macoris, Mariana S; De Marchi, Renata; Janzantti, Natália S; Monteiro, Magali

2012-07-01

This work aimed to investigate the influence of both ripening stage and cultivation system on the total phenolic compounds (TPC) and total antioxidant activity (TAA) of passion fruit pulp. TPC extraction was optimized using a 2³ central composed design. The variables were fruit pulp volume, methanol volume and extraction solution volume. TPC was determined using the Folin-Ciocalteu reaction, and TAA using the ABTS radical reaction. The conditions to extract TPC were 2 mL passion fruit pulp and 9 mL extraction solution containing 40% methanol:water (v/v). TPC values increased in the passion fruit pulp during ripening for both cultivation systems, ranging from 281.8 to 361.9 mg gallic acid L⁻¹ (P ≤ 0.05) for the organic pulp and from 291.0 to 338.6 mg gallic acid L⁻¹ (P ≤ 0.05) for the conventional pulp. TPC values increased during ripening for both organic and conventional passion fruit. The same was true for TAA values for conventional passion fruit. For organic passion fruit, however, TAA values were highest at the initial ripening stages. These results suggest that antioxidant compounds exert strong influence on the initial ripening stages for organic passion fruit, when TPC still did not reach its maximum level. Copyright © 2012 Society of Chemical Industry.

Investigation of Technological Pedagogy Content Knowledge of Pre-Service Science and Technology Teachers

OpenAIRE

Bayram AKARSU; Esra GÜVEN

2014-01-01

The purpose of this study is to investigate Technological Pedagogical Content Knowledge (TPACK) of 3rd and 4th year prospective science teachers, enrollment at the faculty of education, with respect to the technological knowledge (TK), pedagogical knowledge (PK), content knowledge (CK), technological pedagogical knowledge (TPC), pedagogical content knowledge (PCK), and information in the technological content (TPC). These knowledge types are intersection of the sub-dimensions to determine whe...

Preparation and characterization of tetrandrine-phospholipid complex loaded lipid nanocapsules as potential oral carriers

Directory of Open Access Journals (Sweden)

Zhao YQ

2013-10-01

Full Text Available Yi-qing Zhao, Li-ping Wang, Chao Ma, Kun Zhao, Ying Liu, Nian-ping FengSchool of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai, People’s Republic of ChinaBackground: Tetrandrine is an active constituent that is extracted from the root tuber of the Chinese herb Stephania tetrandra S. Moore. It has shown various pharmacological effects, such as antitumor activity, multidrug resistance reversal, and hepatic fibrosis resistance. In clinical applications, it has been used to treat hypertension, pneumosilicosis, and lung cancer. However, the poor water solubility of tetrandrine has limited its application. In this study, a newly emerging oral drug carrier of phospholipid complex loaded lipid nanocapsules was developed to improve the oral bioavailability of tetrandrine.Methods: The phospholipid complex was prepared with the solvent-evaporation method to enhance the liposolubility of tetrandrine. The formation of the phospholipid complex was confirmed with a solubility study, infrared spectroscopy, and a differential scanning calorimetry (DSC analysis. The tetrandrine-phospholipid complex loaded lipid nanocapsules (TPC-LNCs were prepared using the phase inversion method. Lyophilization was performed with mannitol (10% as a cryoprotectant. TPC-LNCs were characterized according to their particle size, zeta potential, encapsulation efficiency, morphology by transmission electron microscopy, and crystallinity by DSC. In addition, the in vitro release of tetrandrine from TPC-LNCs was examined to potentially illustrate the in vivo release behavior. The in vivo bioavailability of TPC-LNCs was studied and compared to tetrandrine tablets in rats.Results: The liposolubility of tetrandrine in n-octanol improved from 8.34 µg/mL to 35.64 µg/mL in the tetrandrine-phospholipid complex. The prepared TPC-LNCs were spherical-shaped particles with a small size of 40 nm and a high encapsulation efficiency of 93.9%. DSC measurements revealed

Optimization of Ficus deltoidea Using Ultrasound-Assisted Extraction by Box-Behnken Statistical Design

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L. J. Ong

2016-09-01

Full Text Available In this study, the effect of extraction parameters (ethanol concentration, sonication time, and solvent-to-sample ratio on Ficus deltoidea leaves was investigated using ultrasound-assisted extraction by response surface methodology (RSM. Total phenolic content (TPC of F. deltoidea extracts was identified using Folin-Ciocalteu method and expressed in gallic acid equivalent (GAE per g. Box-Behnken statistical design (BBD was the tool used to find the optimal conditions for maximum TPC. Besides, the extraction yield was measured and stated in percentage. The optimized TPC attained was 455.78 mg GAE/g at 64% ethanol concentration, 10 minutes sonication time, and 20 mL/g solvent-to-sample ratio whereas the greatest extraction yield was 33% with ethanol concentration of 70%, sonication time of 40 minutes, and solvent-to-material ratio at 40 mL/g. The determination coefficient, R2, for TPC indicates that 99.5% capriciousness in the response could be clarified by the ANOVA model and the value of 0.9681 of predicted R2 is in equitable agreement with the 0.9890 of adjusted R2. The present study shows that ethanol water as solvent, a short time of 10 minutes, and adequate solvent-to-sample ratio (20 mL/g are the best conditions for extraction.

ALICE comes to life

CERN Multimedia

2002-01-01

On 26 March, a first major part of the ALICE detector arrived at CERN: one of the four cylinders in composite material for the Time Projection Chamber (TPC). The construction of the TPC 'field cage' (the structure that defines the configuration of the electrical field of the TPC) is the fruit of exceptional collaboration between CERN and the Austrian manufacturer Fischer Advanced Composite Components (Fischer ACC).

Diogene: a 4π detector, based on a time projection chamber, for studying central collisions of relativistic heavy ions

International Nuclear Information System (INIS)

Gosset, J.

1980-10-01

'Diogene' is the name we have chosen for a 4π solid angle detector, based on a Time Projection Chamber (TPC), designed to perform exclusive measurements of charged particles emitted in central collisions or relativistic heavy ions This detector is being developed by a collaboration between physicists from Saclay, Strasbourg and Clermont-Ferrand, to be installed at the Saturne Synchrotron in Saclay. I shall first give the motivations for our choice of a TPC rather than any other kind of detector, than recall the principle of such a detector, before describing it with more detail and describing its present status and forsean capabilities, including some discussion about the possible extension of such a detector towards higher energies and/or heavier beams

Trigger Algorithms and Electronics for the ATLAS Muon NSW Upgrade

CERN Document Server

Guan, Liang; The ATLAS collaboration

2015-01-01

The ATLAS New Small Wheel (NSW), comprising MicroMegas (MMs) and small-strip Thin Gap Chambers (sTGCs), will upgrade the ATLAS muon system for a high background environment. Particularly, the NSW trigger will reduce the rate of fake triggers coming from background tracks in the endcap. We will present an overview of the FPGA-based trigger processor for NSW and trigger algorithms for sTGC and Micromegas detector sub systems. In additional, we will present development of NSW trigger electronics, in particular, the sTGC Trigger Data Serializer (TDS) ASIC, sTGC Pad Trigger board, the sTGC data packet router and L1 Data Driver Card. Finally, we will detail the challenges of meeting the low latency requirements of the trigger system and coping with the high background rates of the HL-LHC.

Peran Mikoriza Arbuskula pada Insidensi Penyakit Busuk Pangkal Batang Lada

Directory of Open Access Journals (Sweden)

Halim Halim

2017-02-01

Full Text Available Stem rot or foot rot disease caused by Phytophthora capsici is known as an important constraint on pepper cultivation. Research was conducted to determine the effect of arbuskula mycorhizal fungi (AMF on incidence of foot rot disease of pepper seedlings.  The experiment was done in the net house and arranged using completed randomized design with 6 treatments, i.e. (1 soil infested by P. capsici (TPC as negative control treatment, (2 sterilized soil (TS as positive control treatment, (3 TPC with 5 g of AMF, (4 TPC with 10 g AMF, (5 TPC with 15 g AMF, and (6 TPC with 20 g AMF.   Observation involved plant height, number of shoots, disease incidence, the percentage of AMF infection on the roots of pepper plants, and pepper plants dependence on AMF. The results showed that the application of AMF at a dose of 20 g per 10 kg of soil effectively suppressed incidence of foot rot disease and improve plant growth

Influence of different extraction conditions on antioxidant properties of soursop peel.

Science.gov (United States)

Lee, Wei Zin; Chang, Sui Kiat; Khoo, Hock Eng; Sia, Chiaw Mei; Yim, Hip Seng

2016-01-01

Soursop is a healthy fruit. Peels form about 20% of the soursop fruit and are usually discarded as waste product. With a view to utilizing soursop peel as a source of valuable compounds, this study aimed to investigate the influence of different extraction conditions on total phenolic content (TPC) and antioxidant capacity (AC) of soursop (Annona muricata L.) peel. Different ethanol concentrations (20-100%, v/v), extraction temperatures (25- 60°C), and extraction time (1-5 h) were tested. Extracts were prepared on the basis of the best optimal extraction conditions (20% ethanol, 40°C the extraction temperature, and 4 h of extraction time), an optimal TPC and AC was determined for the soursop peel using DPPH, ABTS, FRAP and β-carotene bleaching (BCB) assays. The different extraction conditions tested at best optimum conditions have significantly affected the TPC and AC of the soursop peel. Soursop peel extract extracted in the best optimal extraction conditions had moderate levels of TPC (52.2 μg GAE/ml), and FRAP value (58.9 μg TE/ml extract). The extract demonstrated high BCB inhibitory activity (80.08%). The EC50 values of the extract were high, 1179.96 and 145.12 μg/ml, as assessed using DPPH and ABTS assays, respectively. The TPC was positively and highly correlated with the AC of soursop peel assessed by ABTS, FRAP, and BCB assay, but it was moderately correlated with DPPH radical scavenging activity. A moderate correlation of TPC with DPPH suggested that polyphenols in the extracts were partially responsible for the AC. By-products of soursop such as its peel could be an inexpensive source of good natural antioxidants with nutraceutical potential in the functional food industry.

Prototype ALICE front-end card

CERN Multimedia

Maximilien Brice

2004-01-01

This circuit board is a prototype 48-channel front end digitizer card for the ALICE time projection chamber (TPC), which takes electrical signals from the wire sensors in the TPC and shapes the data before converting the analogue signal to digital data. A total of 4356 cards will be required to process the data from the ALICE TPC, the largest of this type of detector in the world.

Childhood traumatization by primary caretaker and affect dysregulation in patients with borderline personality disorder and somatoform disorder

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Annemiek van Dijke

2011-03-01

Full Text Available Affect regulation is often compromised as a result of early life interpersonal traumatization and disruption in caregiving relationships like in situations where the caretaker is emotionally, sexually or physically abusing the child. Prior studies suggest a clear relationship between early childhood attachment-related psychological trauma and affect dysregulation. We evaluated the relationship of retrospectively recalled childhood traumatization by primary caretaker(s (TPC and affect dysregulation in 472 adult psychiatric patients diagnosed with borderline personality disorder (BPD, somatoform disorder (SoD, both BPD and SoD, or disorders other than BPD or SoD, using the Bermond-Vorst Alexithymia Questionnaire, the self-report version of the Structured Interview for Disorders of Extreme Stress, the Self-rating Inventory for Posttraumatic Stress Disorder (SRIP and the Traumatic Experiences Checklist. Almost two-thirds of participants reported having experienced childhood TPC, ranging from approximately 50% of patients with SoD or other psychiatric disorders to more than 75% of patients with comorbid BPD + SoD. Underregulation of affect was associated with emotional TPC and TPC occurring in developmental epoch 0–6 years. Over-regulation of affect was associated with physical TPC. Childhood trauma by a primary caretaker is prevalent among psychiatric patients, particularly those with BPD, and differentially associated with underand over-regulation of affect depending on the type of traumatic exposure.For the abstract or full text in other languages, please see Supplementary files under Reading Tools online