T. Lux. 13/12/2012 2 Charged particles X-ray (UV) Photons Cathode Anode Amplification Provides: xy position Energy (z position) e- CsI coating.

Gas Detector R&D at IFAE

T. Lux

2

Gas Detector Principle

13/12/2012

Charged particles

X-ray(UV) Photons

Cathode

Anode

Amplification

Provides:• xy position• Energy• (z position)

e-e-

e-

CsI coating

3

Right gas choice and pressure fundamental!Normally: noble gas + quencher gas

Choice depends on: Tracking, photon detection or spectroscopy? Fast gas necessary? (still slower than solid state detectors) Is a high gain required? High rate environment? Is ageing an issue? Safety! Better if not flamable! Sensitive to impurities? Diffusion? -> affects point resolution Complication of the gas system? (open or closed for example) Price!

Gas Choice

13/12/2012

4

Argon, xenon or …?

Which noble gas?

13/12/2012

Stopping power larger in Xenon Better energy resolution in Xenon Argon much cheaper Etc.

pressure

ß but …• pressure vessel + gas

system• attachment • charge gain • voltages

• …

5

Infinite possibilities: CH4, CO2, C4H10, CF4, DME, …

Which quencher gas?

13/12/2012

6

Several advantages about the classical wire readout:

Excellent spatial resolution ( amplification structures: ~100 m) Very good energy resolution Low material budget No ExB effects Cheap Can be produced in large quantities

Micro Pattern Gas Detectors

13/12/2012

GEM

7

1 stage amplification Excellent energy resolution and low threshold (600 eV) Time resolutions below 1 ns possible

MicroMegas (MM)

13/12/2012

8

Amplification within holes of Kapton foil coated with copper Normally operated in cascades -> better stability Can be operated in high rate environments (LHCb: 1

MHz/cm2)

Gas Electron Multiplier (GEM)

13/12/2012

9

2005: Start R&D efforts for a MPGD TPC for T2KEuropean GEM collaboration: UniGe, IFIC, INFN Bari, IFAE

T2K: MPGD Detector R&D

13/12/2012Thorsten Lux (IFAE/UAB) 9/19

• 2 GEM tower• 3 GEM each• ~20x24 cm2• also small setup at IFAE

10

T2K: MPGD Detector R&D

13/12/2012

11

T2K: MPGD Detector R&D

13/12/2012

• IFAE participated in setting up testbench• characterization of ~ 90 MM modules• ~12 m2 readout area• nowadays focus on analysis

12

Electroluminescence (EL)

13/12/2012

between two parallel meshes (G1,G2) a voltage is applied operated below the point where charge amplification sets in linear production of light (~172 nm for Xe) -> better energy

resolution light is read out by PMT/APD/MPPC/… gain of 1000-2000 photons per e- at 10 bar possible

G1

G2

Sensors

e-Drift region

EL gap

Cathode

13

EL Detector R&D

13/12/2012

Started for a DB experiment in 2005 First stage: small HP chamber with 5 APDs Allowed to develop readout electronics Excellent energy resolution achieved Low threshold possible

(8.2 ± 0.1)% FWHM

xenon

13

14

EL Detector R&D

13/12/2012

Larger chamber with 25 APDs Pressure up-to 5 bar Focus on tracking

IEEE 2012 Anaheim 15

EL Detector R&D

2/11/2012

Very primitive cluster finder still

Using the cosmic ray trigger

16

Optimal imaging: MPGD with Pixel readout New project with CNM will start in January Si-MPGD coupled to MediPix chip

Future Project: Si-MPGD R&D

13/12/2012

MIPs

δ-ray!14 mm

17

Choice of gas and pressure allows wide range of application Energy measurement: 0.6 keV – 100+ keV X-rays (with

decreasing detection efficiency for higher energies)

Photon counting at lower energies with coating Point resolutions down to 100-200 m possible Time resolutions below 1 ns possible High radiation hardness Count rates of 1 MHz/cm2 possible MPGD allow to cover large areas to reasonable costs

Gas detector knowledge available at IFAE but a gas detector for a ESRF source would require a dedicated R&D program

13/12/2012

Summary

Backup Slides

19

G.C. Smith, Gas-based detectors for synchrotron radiation, Journal of Synchrotron Radiation, Vol. 13, page 172-179, 2006

J.E. Bateman et al., A gas microstrip wide angle X-ray detector for application in synchrotron radiation experiments, NIM A, Volume 477, Issues 1–3, 21 January 2002, Pages 340-346

M. Kocsis et al., A novel gas-filled detector for synchrotron radiation applications, NIM A, Volume 563, Issue 1, 1 July 2006, Pages 172-176

M. Kocsis, The status of gas-filled detector developments at a third generation synchrotron source (ESRF), NIM A, Volume 471, Issues 1–2, 21 September 2001, Pages 103-108

13/12/2012

Literature

20

The neutrino group at IFAE has built up in the last 7 years a significant amount gas detector knowledge:

2005-2008: MPGD R&D for the T2K TPCs 2008-2012: Electroluminescence detector R&D

Future projects at IFAE: 2013-2015: Development of a Si-MPGD with

MediPix readout

History at IFAE

13/12/2012