Detector Challenges in Photon Science. Heinz Graafsma DESY-Hamburg; Germany & University of Mid-Sweden
Outline > Photon Science and the detector challenge > Synchrotron storage rings § The LAMBDA system > X-ray Free Electron Lasers § The DSSC system § The AGIPD system > XUV Free Electron Lasers § The PERCIVAL system > Future directions Heinz Graafsma | Page 2
From fundamental to applied science Study of extremely charged ions Structure of viruses Authentication of paintings Heinz Graafsma | Page 3
Photon-Science at large scale X-ray facilities PETRA III FLASH I + II European XFEL Heinz Graafsma | Page 4
The Detector Challenge: FEL Sources PETRA-3 2 1 2 1 ESRF (2000) 2 1 brilliance 2 1 ESRF (1994) 1 1 1 1 Storage Ring Sources 1 1 1 1 Second generation 1 1 1 1 First generation 1 1 1 1 1 1 1 1 X-ray tubes 9 1 8 1 7 1 6 1 1900 1960 1980 2000 Heinz Graafsma | Page 7
Outline > Photon Science and the detector challenge > Synchrotron storage rings § The LAMBDA system > X-ray Free Electron Lasers § The DSSC system § The AGIPD system > XUV Free Electron Lasers § The PERCIVAL system > Future directions Heinz Graafsma | Page 8
Storage Ring Sources: general observations PETRA III • Pulsed X-ray source • ~ Giga Hz rep-rate • Treated as a continuous, random source • Main photon range: 5-30 keV • Few stations <1 keV • Few stations > 100 keV • 30 large synchrotrons world-wide • ~ 800 end-stations Heinz Graafsma | Page 9
Hybrid Pixel Array Detectors (HPADs) Pixelated Particle Particle / X-ray Sensor Amplifier & Readout Chip Q signal CMOS Connection wire pads Power Power Inputs Indium Solder Outputs Clock Inputs Bumpbonds Data Outputs Particle / X-ray � Signal Charge � Electr. Amplifier � Readout � Digital Data Heinz Graafsma | Page 10
Medipix-3: Communicating pixels 55 µ Heinz Graafsma | Page 13
Medipix-3: Communicating pixels The winner takes all principle √ • The incoming quantum is assigned as a single hit 55 µ Heinz Graafsma | Page 14
Communicating pixels Ł better energy resolution Heinz Graafsma | Page 15
Medipix3 readout chip > Collaboration of ~20 groups led by CERN > Flexible pixel design § 2 counters and thresholds per 55µm pixel, plus interpixel communication > Applications: § Fast, deadtime-free frame readout • 2000 fps @ 12 bit depth § Energy binning with charge summing § Pump / probe… Heinz Graafsma | Page 16
Large Area Medipix3 Based Detector Array (LAMBDA) Heinz Graafsma | Page 19
High-Z pixel detectors > Aim: Increase efficiency at 50 keV by factor of 10 § Replace silicon sensor in LAMBDA with high-Z semiconductor § Combine high QE with hard X-rays, high frame rate, high signal-to-noise > Investigating different materials in collaboration with other institutes and industry § Cadmium telluride § Gallium arsenide § Germanium Heinz Graafsma | Page 22
High-Z sensors > CdTe, GaAs and Ge can be used for experiments > Each material has strengths and weaknesses § CdTe – most well-established, still some problems with uniformity and stability § GaAs – widespread but correctable non-uniformity – very limited supply § Germanium technology now works – but high cooling power for large systems CdTe GaAs Ge Heinz Graafsma | Page 23
Outline > Photon Science and the detector challenge > Synchrotron storage rings § The LAMBDA system > X-ray Free Electron Lasers § The DSSC system § The AGIPD system > XUV Free Electron Lasers § The PERCIVAL system > Future directions Heinz Graafsma | Page 25
The European X-ray Free Electron Laser • 17.5 GeV linear electron accelerator (3.4 km) • producing 5-25 keV x-rays (tunable) through FEL process • unprecedented peak brilliance DESY • user facility: common infrastructure shared by many experiments Switch Building (Osdorfer Born) Experimental Hall (Schenefeld) Heinz Graafsma | Page 26
The XFEL-Challenge: Different Science • Completely new science x10 9 • Fast science 100 fsec • “Single shot” science Heinz Graafsma | Page 27
The Holy Grail ? K. J. Gaffney and H. N. Chapman, Science Heinz Graafsma | Page 28 8 June 2007
European XFEL Linac: Time Structure Challenge Elect r on bunch t r ains; up t o 2700 bunches in 600 µ sec, r epeat ed 10 t imes per second. Pr oducing 100 f sec X-r ay pulses (up t o 27 000 bunches per second). 100 ms 100 ms 27 000 bunches/ s 600 µ s with 99.4 ms 4. 5 MHz repitition rate 220 ns av. Rate: 27kHz XFEL FEL 120Hz LCLS process X- ray photons 60Hz SCSS <100 f s Heinz Graafsma | Page 29
What are the challenges ? 4.5 MHz Heinz Graafsma | Page 30
How to meet the challenge ? Three dedicated Projects: • Depfet Sensor with Signal Compression Non-linear gain, digital storage Adaptive Gain Integrating Pixel Detector • Automatic adaptive gain, analogue storage • Large Pixel Detector Three parallel gains, analogue storage Heinz Graafsma | Page 31
DSSC - DEPMOS Sensor with Signal Compression > DEPFET per pixel > Very low noise (good for soft X-rays) > non linear gain (good for dynamic range) > per pixel ADC > digital storage pipeline > Hexagonal pixels 200 µ m pitch > MPI-HLL, Munich > Universität Heidelberg > Universität Siegen • combines DEPFET > Politecnico di Milano • with small area drift detector > Universit à di Bergamo (scaleable) > DESY, Hamburg Heinz Graafsma | Page 32
DSSC - DEPFET Sensor with Signal Compression DEPFET : Electrons are collected in a storage well ⇒ Influence current from source to drain gate drain source Storage well Fully depleted silicon e - Output voltage as function of charge injected charge injected charge Heinz Graafsma | Page 33
The Adaptive Gain Integrating Pixel Detector (AGIPD)
Adaptive Gain principle High dynamic range: Dynamically gain switching system Extremely fast readout (200ns): 1,8 Analogue pipeline storage C3 Control logic Analogue encoding 1,6 C2 1,4 Normal Charge C1 1,2 Output Voltage [V] sensitive amplifier V thr ≅ V ADCmax 1,0 Discr. Trim DAC 0,8 Leakage comp. 0,6 0,4 0,2 Cf=100fF Cf=1500fF Cf=4800fF 0,0 0 5000 10000 15000 Number of 12.4 KeV - Photons Heinz Graafsma | Page 37
AGIPD readout principle Electronics per pixel Sensor Pixel matrix Read Out bus … HV Analog Mem CDS SW + RO Amp DAC Analog Mem - CTRL … THR Calibration circuitry Mux Chip ASIC Adaptive gain amplifier output periphery 352 analog memory cells driver Heinz Graafsma | Page 38
AGIPD Pixel Electronics • 200 x 200 micron 2 pixels • 352 storage cells + veto possibilities. • M inumum signal ~ 300 e - = 0.1 photon of 12.4keV • M aximum signal ~ 33 10 6 e - = 10 4 photons of 12.4keV • 4.5 M Hz frame rate • 64 x 64 pixels per ASIC • 2 x 8 ASICs per module (128x512 pixels, no dead area) • 4 modules per quadrant Heinz Graafsma | Page 39
AGIPD modules Special Radiation hard design Special design to minimize dead area AGIPD 1.0 Heinz Graafsma | Page 45
A 1M pixel camera with a variable hole • Protruding out of detector vessel to minimize sample to detector distance • Independently movable quadrants • Angled electronics to minimize footprint along beam axis Heinz Graafsma | Page 46
The Real thing Heinz Graafsma | Page 47
Experiments: AGIPD module @APS Single bunch imaging – a challenge to find processes fast enough Experimental setup ● Drilled equidistant holes into a DVD ● DVD covered with zinc paint to increase absorption ● Mounted DVD on a fast electric motor ● Measurement of hole to hole frequency ● with diode and oscilloscope: 1.208kHz Heinz Graafsma | Page 48
Experiments: AGIPD module @APS Calculation for burst imaging Result from laser measurement • APS bunch spacing: t = 154ns • Number of pixels crossed during burst of 352 images: ~ 8 • Pixel size: 200µm Vdisc, AGIPD = Vdisc, Laser = ͌ 29.51m/s 29.83m/s Single bunch imaging is possible even at a repetition rate of 6.5MHz!! Heinz Graafsma | Page 49
Outline > Photon Science and the detector challenge > Synchrotron storage rings § The LAMBDA system > X-ray Free Electron Lasers § The DSSC system § The AGIPD system > XUV Free Electron Lasers § The PERCIVAL system > Future directions Heinz Graafsma | Page 50
(Pixelated Energy Resolving CMOS Imager, Versatile And Large) Soft X-ray imaging MAPS for (X)FELs and synchrotrons
P ERCIVAL in a nutshell > Aim: develop X-ray imager for FELs’ and Storage Rings > 250eV-1keV, 2Mpixel & 13Mpixel, 27 micron pixels, 120Hz frame rate, 1-10 5 photons/pixel. Fully functional below 250 eV and above 1 keV. > Partners: DESY, RAL/STFC, Elettra, Diamond (DLS) & Pohang Light Source (PAL) § Sensor developed at RAL, § System developed DESY, Elettra, DLS and PAL § Only digital information coming off the chip § Readout development build upon / re-use XFEL and AGIPD developments > Project timeline § TS1.2 to be tested this summer § First full 2M system 2016 Heinz Graafsma | Page 52
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