Développements de détecteurs utilisables pour des X au CEA/IRFU( ex DAPNIA Saclay) Eric Delagnes eric.delagnes@cea.fr.

Présentation au sujet: "Développements de détecteurs utilisables pour des X au CEA/IRFU( ex DAPNIA Saclay) Eric Delagnes eric.delagnes@cea.fr."— Transcription de la présentation:

1 Développements de détecteurs utilisables pour des X au CEA/IRFU( ex DAPNIA Saclay) Eric Delagnes

2 Panorama des développements à L’IRFU
MAPS: Collaboration proche avec l’IPHC dans le cadre d’EUDET (et +) => cf présentation. de M. Winter Quelques contacts pris par Fabienne Orsini à Soleil. Matrices de Micro bolomètres X: R&D en cours de démarrage (XEUS->IXO)/ (Claude Pigot). Détecteurs CdTe: Spectro-imageurs spatiaux X durs et Gamma basse énergie à haute résolution spectrale (Olivier Limousin). Détecteurs gazeux: Micromégas et dérivés (David Attié / Ioannis Giomataris). Résultats : +prise de conscience des problèmes de connectique.

3 Détecteurs CdTE pour expériences spatiales
. Détecteurs CdTE pour expériences spatiales Long term R&D effort => Developments for 2 X / g spectro-cameras: for ECLAIRs et SIMBOL-X satellites using common tools (ASICs..) A 20 m focal length observatory to detect hard X-rays (0.5 keV-80 keV) by focusing technique. Sensibility and angular resolution improved of two orders of magnitude compared to telescopes with indirect imaging. Two satellites flying in formation High Energy Detector made with a matrix of pixelated CdTe detectors 64mm2 surface 625µm pitch pixels 100ns time resolution. Range: 4KeV- 80 KeV. resolution <1.2keV 60keV Mirror spacecraft Résultats : +prise de conscience des problèmes de connectique. Detector spacecraft Observation of high energy phenonema (matter accretion near black holes, matter ejection in quasars…)

4 CALISTE 64 => 256 Cd(Zn)Te 64-pixel detector (1mm pitch, 1 or 2 mm thick) IDeF-X V1.1 ASIC 16 analog channels Mounting on PCB 4 ASIC Stacking Caliste 64 camera 10 mm 18 mm Electronic module with a 7 x 7 PGA X radiography

5 SPECTROSCOPY results Individual spectrum -10°C, -400V, 241 Am
Low threshold ~1.5 keV Ex. Pixel 1: keV keV Statistics on 64 pixels Uniformity Mean FWHM 705 keV keV M X-ray fluorescence line Np (3.3 keV) Low threshold

6 From CALISTE 64 to CALISTE 256
Three images in energy range around 60 keV, with W collimator, Cu mark, -100V, +30°C, 1min Next step for Simbol-X: CALISTE 256: test started oct 1st 256 pixels of 625 µm pitch (Simbol-X geometry)

7 Les progrès des détecteurs gazeux basés sur Micromégas sur PCB ou Kapton
Drift field typical V/cm Amplification field typical V/cm mm BULK or µbulk Micromegas manufacturing technique New techniques: Cheap, Ease of construction. Large surface 5-150ns (geometry dependant) Energy resolution CAST readout 300 mm pitch (Kapton) Gain stability over 7 months (less than 5%) in the CAST experiment stability High radiation hardness High fluxes tolerant. granularity (strips, pads) space resolution ~50µm Fe55 6keV source <12% FWHM (microbulk technique)

8 Vers une convergence gaz-semiconducteur ?
Solid detector Gas detector = digital TPC x, y, F(x, y)  2D x, y, z(t), E(x,y)  3D Drift cathode grid X-ray source + - Ionizing particle Gas volume Semiconductor sensor Flip-chip bump bonding connections + - Amplification System (MPGD) Medipix2/TimePix chip TimePix chip, could be a XPAD chip

9 Description of the TimePix chip
Chip (CMOS ASIC) upgraded in the EUDET framework from the Medipix2 chip developed first for medical applications IBM technology 0.25 μm on 6 layers Characteristics: surface: 1.4 x 1.6 cm2 matrix of 256 x 256 pixel size: 55 x 55 μm2 For each pixel: preamp/shaper/discri/ 14 bit Counter + reg Three Main Modes of operation: counting. Timing. Time over Threshold => charge Noise: ~ 650 e- 70 e- per pixel, Cin ~ 15 fF Readout ~ms Pixel 1 2 3 4 5 55 μ m 14111 m 16120 m 14080 m (pixel array) 55 mm Synchronization Logic Interface Preamp/shaper Configuration latches Counter THL disc. Llopart et al., NIMA 581 (2007) 361

10 Micro-TPC using TimePix/Micromegas
Micro-TPC with a 6 cm height field cage Size : 4 cm × 5 cm × 8 cm Windows for X-ray sources Cover Windows for β sources 6 cm Field cage Micromegas mesh Gas mixture at atmospheric pressure TimePix chip

11 Integration de la grille et de la protection sur le silicium
Integrate Micromegas detector directly on a CMOS chip by post-processing Resistive layer for protection of a-Si:H IMT Neuchatel NIKHEF (MESA+, Univ. Twente) Gap: 50 μm; Hole pitch: 32 μm,Ø: 14 μm 55Fe Spectrum KKβ-filtered spectrum with Cr foil) Ingrid flatness => improved E resolution. 11.7% FWHM

12 Micro-TPC TimePix/Micromegas
TimePix chip + SiProt 20 μm + Micromegas 55Fe source Ar/Iso (95:5) Time mode z = 25 mm Vmesh = -340 V tshutter = 283 μs

13 Measurements of primary statistics in gases
Diffusion σt should be big enough to separate electrons: e- per pixel ~ 1 Study of primary electrons and Fano factor F using RMS Spectrum of number of electrons for 2000 events: F: Fano factor √b: single e- gain distribution rms (%) ε: detection efficiency N: number of primary e- Sensitive to Kα & Kβ lines FWHM = 9,5 % 5.9 keV line at ~ 226 e- TimePix+Ingrid+ 15 μm SiProt Argon + 5% Isobutane

14 Polarimetry using photoelectric absorption
Ideal polarimeter is a track imager with: resolution elements < mean free path of photoelectron Differential photoelectron cross-section emitted from the atomic s-orbital in non relativist limit: θ polar angle, φ azimutal angle Emission angles are modulated by the polarization P maximum in the plane γ direction Nmax Nmin

15 Prototype TPC polarimeter using TimePix/Micromegas
TimePix chip + SiProt 20 μm + Micromegas 55Fe source Ne/Iso (90:10) TOT mode z < 5 mm Vmesh = -450 V tshutter = 0.2 s

16 EXTRA SLIDES

17 CdTe Efficiency vs Energy
. CdTe Efficiency vs Energy Résultats : +prise de conscience des problèmes de connectique.