the agipd detector for the european xfel
DESCRIPTION
The AGIPD Detector for the European XFEL - PowerPoint PPT PresentationTRANSCRIPT
The AGIPD Detector
for the European XFEL
Julian Becker (DESY), Roberto Dinapoli (PSI), Peter Goettlicher (DESY),
Heinz Graafsma (DESY), Dominic Greiffenberg (PSI), Marcus
Gronewald (U Bonn), Beat Henrich (PSI), Helmut Hirsemann (DESY),
Stefanie Jack (DESY), Robert Klanner (U Hamburg), Hans Krueger (U
Bonn), Alessandro Marras (DESY), Aldo Mozzanica (PSI), Bernd
Schmitt (PSI), Xintian Shi (PSI), Ulrich Trunk (DESY), Jiaguo Zhang (U
Hamburg)
XFEL -Detector Requirements
Unique time structure of the beam: • 600 µs long bunch trains at a repeatition rate of 10 Hz
• Each train consists of 2700 bunches with a separation of 220 ns
• (SASE) Each bunch consists of ~1012 photons arriving <100 fsOther specifications:
• 27000 X-ray flashes per sec
• Wavelength: 0.1 .. 6 nm (12.4 .. 0.2 keV)
• Peak Brilliance: 5.1033 ph/(s.mm2.rad2.
0,1% bandwidth)
XFEL -Detector Requirements
Beam provides
Simultaneous deposition of all photons
Challenges
Single photon counting not possible
Approach
Charge integration
High number of bunches
2700 bunches per train (600 µs)
Reading out of single frames impossible
Analog storage on >200 storage cells
Dynamic range of the detector: 0 … <104 ph/pixel
Dynamic gain switichng
3 gain stages
Single photon counting capability for highest gain
The AGIPD Detector
64 x 64 pixels
2 chips
8 chips
4 modules
Specifications
• 1 Mpixel
• 16 modules (4 x 4)
1 module: 8 x 2 chips,
1 chip: 64 x 64 pixel
• Pixel size:
200 x 200 µm2
• Sensor:
500 µm thick Si
• Hole for direct beam
• Active cooling
AGIPD - Prototypes
AGIPD 0.1 AGIPD 0.2 AGIPD 0.3
• No pixels yet
• 3 readout blocks consisting of:
Readout chain (Preamp + CDS stage)3 different kinds of leakage current compensation
• 16 x 16 pixels
• 100 storage cells
• No leakage current compensation
• Different combinations of preamps and storage cell architechures
• 16 x 16 pixels
• 200 storage cells
• Radiation hard storage cell design
• High speed serial control logic
AGIPD – Characterization
AGIPD 0.1 AGIPD 0.2 AGIPD 0.3
• Linearity of the gain
• Stress-test of the input gate at the preamp
•Temporal behavior of the preamp and CDS stage
• Energy calibration
• Noise determination
• Pixel-to-Pixel variations
• Storage cells variations
• First imaging
• Radiation hardness of storage cells
• Test of the high speed serial control logic
AGIPD 0.1 - Linearity of the gain(before stress-test)
• Linearity test using a pulser applying voltage pulses on a 11 pF input capacitance:
A voltage pulse of 1 V corresponds to an equivalent charge of ~20000 x 12 keV photons
Pulsing with 1 kHz for 1 hour: 3.6 106 x 20k 12 keV photons
• Rise time of the pulse: 5 ns
AGIPD 0.1 - Linearity of the gain(before stress-test)
High gainstage:0.35 % (rms) 0.27 x 12 keV ph. (max)(range: 7 .. 51 x 12 keV ph.)
Medium gainstage:0.15 % (rms)2.6 x 12 keV ph. (max)(range: 360 .. 1500 x 12 keV ph.)
Low gainstage:0.13 % (rms)11.8 x 12 keV ph. (max)(range: 2000 .. 7000 x 12 keV ph)
AGIPD 0.1 -Linearity of the gain
(after stress-test)
Are the pulses arriving fast enough? How does the switching look like?
Direct measurements (Preamp/CDS)High gainstage
Resumee:
• Risetime of pulser is 5 ns
• Preamp and CDS are properly working within ~50 ns
No switching
Direct measurements (Preamp/CDS)Low gainstage
2x switchings
Resumee:
• Preamp and CDS are properly working within ~50 ns, also when gain switching 1x and 2x
AGIPD 0.2 – Energy calibration
• Energy calibration done using X-ray fluorescence from Ge (10 keV), Mo (17.5 keV) and Sn (25 keV)• Integration time was 1 s• Sensor voltage 120 V• 600000 frames investigated per photon energy Ge (10 keV) Mo (17.5 keV) Sn (25 keV)
Nonlog scale to demonstratelow number of fluorescence photons!
AGIPD 0.2 – Energy calibration / Noise
Noise measurements with an integration time of 100 ns reveal a value of (1.15 ± 0.11) keV, corresponding to an ENC of (318 ± 30) e-
SummaryAGIPD 0.1
• Linearity better than 1 % for all gain stages
• Input gate stress-test revealed no degradation neither in gain nor in linearity after extensive pulsing with an equivalent of up to 7.108 x 1.1.105 12 keV photons
• Rise time of the preamp and CDS ~ 50 ns (within expectations)
AGIPD 0.2
• Noise: (1.15 ± 0.11) keV = ENC of (318 ± 30) e-
Single photon resolution demonstrated for high gain stage
• Pixel-to-Pixel variations: ± 1.9 % (rms)
• Storage Cell variations: ± 0.65 % (with simple correction algorithm): ± 0.01 %
• Imaging capability shown