Evaluation of the SOI Pixel Detectors by Synchrotron Radiation X-ray at KEK/PF KEK IMSS R. Hashimoto, S. Kishimoto, R. Kumai, N. Igarashi KEK IPNS Y. Arai, T. Miyoshi RIKEN T. Hatsui, T. Kudo IHEP Yunpeng Lu、 Yang Zhou、 Qun Ouyang SOKENDAI R. Nishimura

Outline ・ Introduction ・ XRD experiment by the SOPHIAS detector ・ Evaluation of the counting type pixel ・ Summary

Introduction Development of the SOI area detector using for X-ray structural analysis. ・ X-ray diffraction (XRD) experiment for functional materials. ・ Small angle X-ray scattering (SAXS) experiment for functional thin films. etc…

Introduction X-ray diffraction (XRD) Å order Structural analysis at the atomic level Small angle X-ray scattering (SAXS) nm order molecular level Area detector using SOI +P -P Crystal, Thin film Precise analysis of position for hydrogen atoms Time response of the domain structure by pulsed external electric field X rays Complementary use of hard and soft X-ray Glazing-Incidence SAXS experiment

Introduction Requests for detectors from experiments ・high frame rate ・high sensitivity ・high spatial resolution Realizing by counting type pixel

Introduction Requests for detectors from experiments ・high frame late ・high sensitivity ・high spatial resolution Realizing by counting type pixel Checking the importance of the fine pixelated detector by use of the SOPHIAS detector in X-ray structural analysis. In this talk, our current works (following 2 topics) will be shown. ・ XRD experiment by the SOPHIAS detector ・ Evaluation of the counting type pixel

Outline ・ Introduction ・ XRD experiment by the SOPHIAS detector ・ Evaluation of the counting type pixel ・ Summary

XRD experiment by the SOPHIAS detector SOPHIAS (RIKEN, Hatsui group) ・ Charge integrating type detector Pixel Size 30 um×30um Pixel Number 1.9 M Chip size 65.598 mm ×30.58 mm Frame Rate 60 frame/sec Noise 150 e-rms Depletion Depth 500 μm @VHV=200V Peak Signal 7 Me-/pixel Photon Energy limitation < 7 keV (for FEL) Gain High : 7.2uV/e Low :0.15uV /e H:L=50:1 SOPHIAS MPCCD COTS CCD Takaki. Hatsui, Vol. 27, No. 4, 2014, Synchrotron Radiation News Allowing high dynamic range

XRD experiment by the SOPHIAS detector Setup @KEK/PF BL-8A Camera length ～150 mm Sample location X-ray Sample is in front of the SOPHIAS SOPHIAS on the IP diffractometer

XRD experiment by the SOPHIAS detector Sample : SmBaMn2O6 Material property ・ Changes in the ferroelectric in the transition phase in XRD measurement, normal phase → 1 peak transition phase → Split into very close 2 peaks Phys. Rev. B 90 241113(R) (2014)

XRD experiment by the SOPHIAS detector EX-ray = 18 keV 1-D transformation by circular integration

XRD experiment by the SOPHIAS detector IP (100 μm square pixel) SOPHIAS Camera length ～190 mm Camera length ～150 mm SOPHIAS had disadvantage in camera length but made good result!

Outline ・ Introduction ・ XRD experiment by the SOPHIAS detector ・ Evaluation of the counting type pixel ・ Summary

Evaluation of the counting type pixel Collaborative research between IHEP and KEK. Development of the pulse-counting-type fine pixelated X-ray detector based on Double-SOI technology. TEGs CPIXTEG3b (IHEP) : 50 μm square pixel, 64×64 array Under evaluation. CPIXPTEG1 (KEK) : 64 μm square pixel, 32×32 array Now suspended. Each pixels has just one contact to Middle-SOI layer. → does not work enough. ⇒ In this winter, CPIXPTEG2 will be rollout. It has many contacts.

Evaluation of the counting type pixel Setup @KEK/PF BL-14A 10 μmφ beam mode TEG chip CPIXTEG3b /CPIXPTEG1 X-ray pin-hole X-ray filter Ionization chamber

Evaluation of the counting type pixel Setup @KEK/PF BL-14A Flat field beam mode Scattering target (Glassy carbon) X-ray

Evaluation of the counting type pixel Recovery from the total ionization dose (TID) effect by use of Middle-SOI. Typical pulse shape of the Shaper amp. of CPIXPTEG1. TID effect require some voltage to Middle-SOI Middle-SOI 0 V Middle-SOI -1 V (Before X-ray exposure) Shaper pulse was recovered.

Evaluation of the counting type pixel CPIXTEG3b CSR calibration The discriminator can be adjusted by 4-bit CSR on each pixels. S-curve before/after CSR calibration using a pulse generator Before calibration After calibration Counts Input pulse height Vin@negative (mV)

Evaluation of the counting type pixel Mean distribution of S-curves Before After Numbers of pixel σ value became better to about 5 times. Before : 4.57 mV → After : 0.95 mV @ input pulse height

Evaluation of the counting type pixel Before After Check by the flat field X-ray beam In the test of threshold level scan with flat field X-ray, threshold dispersion became half by CSR calibration. Before : 26 nA → After : 14 nA @threshold level

Evaluation of the counting type pixel 1-dimensional pixel array scan by 10 μmφ beam EX-ray = 16 keV, VHV = -120 V, exposure time = 2 sec 1 2 3 4 ・ : Maximum counts in pixel array ・ : Total counts of all pixels ・・・・ : Counts of each pixels

Evaluation of the counting type pixel Fitting by f(x) = p0 * Freq( ( x-p1 )/p3 ) * ( 1-Freq( ( x-( p1+p2 ) )/p3 ) ) p2 : size of a pixel (μm) ～ 45 μm → 5 μm smaller due to shortage of the charge collection efficiency in peripheral area of the pixel. p3 : degree of the charge sharing effect @σ (μm) ～ 6 μm

Evaluation of the counting type pixel 2-dimensional pixel array scan by 10 μmφ beam Very low sensitivity in corners of a pixel. Charge was shared in 4 pixels. Edge of the pixel array Row 63 Row 62 Row 61 Black line : boundary of the pixel

Evaluation of the counting type pixel 2-dimensional pixel array scan by 10 μmφ beam Very low sensitivity in corners of a pixel. Charge was shared in 4 pixels. CNPIX1 (Arai-san’s talk) hexagonal shape and prevents to charge sharing effect. This is expected to solve the problems of the square pixel. Edge of the pixel array Row 63 Row 62 Row 61 Black line : boundary of the pixel

Summary XRD experiment by the SOPHIAS detector SOPHIAS succeeded to separate very close 2 peaks with 150 μm camera length. On the other hand, IP failed to separate although it had advantage in camera length. → Fine size pixel is an important tool, especially in the experiment where camera length is limited in short distance. Evaluation of the counting type pixel X-ray tests of the CPIXTEG3b/CPIXPTEG1 were done in KEK/PF. It was noticed that the peripheral part of the pixel had low sensitivity to X-ray. → CNPIX1 prevents this problem. The X-ray test for it will be planed end of FY2016 (more happy case, end of this year).