1 / 31

GEM Detector

GEM Detector. Shoji Uno KEK. Wire Chamber. Detector for charged tracks Popular detector in the particle physics, like a Belle-CDC Simple structure using thin wires. Electron. Anode wire. Gas amplification near anode wire.

zilya
Télécharger la présentation

GEM Detector

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. GEM Detector Shoji Uno KEK

  2. Wire Chamber • Detector for charged tracks • Popular detector in the particle physics, like a Belle-CDC • Simple structure using thin wires

  3. Electron Anode wire Gas amplification near anode wire • High electric field (>30kV/cm) can be obtained easily due to using thin wire (diameter ~0.03mm) • Energy of electron become higher for high electric field near wire. • Electron can produce another electron for ionization. • Number of electrons increases due to multi steps of this process. (gas amplification、 electric avalanche) • Gas gain up to ~105 can be obtained easily.

  4. Recent gas chamber • Requirement • High incident rate • One wire covers wide region. • Wire spacing > ~1mm • Length >~10cm Need more space • Pure two-dimensional readout • Wire has some limitation due to straight wire LHCATLAS

  5. Limitation of wire chamber

  6. New development • Development MPGD（MicroPattern Gasdetector) • Gas multiplication in high electric field with other than wire • 3 types • MSGC（MicroStripGasChamber） • MICROMEGAS（MicromeshGaseousDetector） • GEM（GasElectron Multiplier）

  7. GEM (Gas Electron Multiplier) Double side flexible printed circuit board Electric field Hole diameter70mm Hole pitch140mm Thickness50mm Cu thickness5mm • Developed by F.Sauli (CERN) in 1997. • NIMA 386(1997)531

  8. Flexible shape Fabio Sauli

  9. Configuration for GEM detector Readout

  10. Multi-layer

  11. High counting capability ワイヤーチェンバー GEM

  12. Application of GEM • Feature of GEM • Pure two-dimensional readout 　→　Image • Multi-layer structure • Stable operation • Multi-conversion-layer(Neutral  Charged) • High counting capability • GEM can be applied for many other fields, not only high energy physics.

  13. TPC

  14. X-ray detector X-ray absorption tomography Crystal structure analysis using X-ray

  15. Photon sensor • Same function for photomultiplier • Usable in Magnetic field • Fine segmentation in readout • Cheap and Larger • Key issue is photo-electric surface in gas volume. • Under developement

  16. Basic property of GEM chamber

  17. 55Fe (5.9 keV X-ray) DRIFT 10 mm GEM1 1mm TRANSFER 1 ～2 mm GEM2 TRANSFER 2 ～2 mm GEM3 ～2 mm INDUCTION PCB TestChamber PCB □15mm×15mm 36＝6×6 2200pF 2200pF GAS Ar-CH4(90/10) (P-10) Ar-CO2(70/30)

  18. Pulse shape 200ns Signal from GEM foil 130mV Signal from Readout pad

  19. P10 Ar-CO2 Effective gas gain and resolution 55Fe Ar-CH4(90/10) Sigma/Mean = 8.8% Number of events DVGEM=325V Edrift = 0.5kV/cm Etransfer = 1.6kV/cm Einduction= 3.3kV/cm Pedestal=104.6 ADC counts

  20. Gas gain vs various parameters P10 Ar-CO2 P10 Ar-CO2 EI ED Ar-CO2 P10 Ar-CO2 EI ET

  21. Electric field dependence in drift region In case of weak field In case of strong field ED=500V/cm ED=3000V/cm ΔＶＧＥＭ＝３２０Ｖ ΔＶＧＥＭ＝３２０Ｖ EI=1000V/cm EI=1000V/cm 55Fe (5.9 keV X-ray) Ｄｒｉｆｔ region ED ΔVGEM=360V ET=1.6kV/cm EI=3.6kV/cm Electric field (kV/cm) Ionization occurs in drift region Electrons enter into GEM holes. Collection Efficiency

  22. ADC SUMADC ADC counts 63 0 Channel σ＝359.7±0.4 μm Charge distribution ΔVgem＝３３０V Ed= 0.5 kV/cm Et=1.65 kV/cm Ei= 3.3 kV/cm P10 Normalized ADC counts One event ｍｍ -1 0 1 dX (each strip – C.O.G) ｄX（各strip－C.O.G) σ＝181.2±0.3 μm ΔVgem＝３７０V Ed= 0.5 kV/cm Et=2.59kV/cm Ei=5.18 kV/cm Ar-CO2 (70/30) Normalized ADC counts ｍｍ -1 0 1 ｄX（各strip－C.O.G) dX (each strip – C.O.G)

  23. Charge spread 0.546mm/√cm P10 MagBoltz P10 0.258mm /√cm Ar-CO2 Ar-CO2 Diffusion is dominant factor.

  24. Application of GEM Shoji Uno (KEK-DTP) • Neutron detector • X-ray detector • Soft X ray • Hard X ray • Light

  25. Application to Neutron Detector • Expensive 3He Gas is not necessary. • No pressure vessel • Free readout pattern • High resolution • Position and Time • Insensitive against g-ray • Capability against high counting rate Ar-CO2 Cathode plate With B10 B10 coated GEMs Normal GEM Readout board

  26. Chamber structure Ar/CO2 = 70:30 Thickness of Boron-10 : 4.4mm 2.0mm + 0.6mm ×4 8 mm Al - 10B cathode ED = 1.5 kV/cm 1 mm ( 0.5mm ) 150V (75V) B GEM 1 240V 1 mm ET = 1.5 kV/cm 150V B GEM 2 240V 1 mm ET = 1.5 kV/cm 150V GEM 1 400V ET = 2.2 kV/cm 2 mm 440V GEM 2 370V EI = 4.0kV/cm 2 mm 800V X(120) +Y (120) strips 0.8mm pitch Readout strip

  27. I/F One HV cable Three LV cables One Ethernet cable Electronics 8 ASIC chips + 1 FPGA FE2009 ASIC : KEK-DTP Data transfer and Control through Ethernet SiTCP by T. Uchida（KEK） Using Note-PC Present Detector System Ethernet Electronics Low Voltage GEM Chamber Compact and Portable System T.Uchida et. al., "Prototype of a Compact Imaging System for GEMdetectors," was published on IEEE TNS 55(2008)2698.

  28. Data samples The beam profile and its TOF distribution L = 18789 mm ~ 18.8 m L: distance from the source to the detector An image of a cadmium slit and its TOF distribution (Å) L = 18789 mm 27 mm Events from 1.5 Å to 8 Å are selected 60 mm Cd cutoff The thickness of the slit ~0.5 mm This image is produced with a wavelength cut. (Å) Our system can obtain a 2D image and its TOF at the same time. 11

  29. Energy Selective Neutron Radiography Resonance absorption region(E>1eV) Bragg Edge region (Thermal and cold)

  30. Resonance absorption imaging By T. Kai (JAEA) et al. at BL10 in J-PARC

  31. One more demonstration TEST Sample Ratio of ToF spectrums with/without sample EURO coin gold coin Imaging data with around 450msec ToF

More Related