1. But for synchrotron data collection we wanted even faster image readout

2. Quantum Array Detectors
188 mm
(7.4”)
210 mm
(8.3”)
Quantum 4R
2304 x 2304 pixels
5 M pixels
10 Mbyte images
9 sec. readout
1.1 Mbytes/sec
Quantum 210
4096 x 4096 pixels
16 M pixels
32 Mbyte images
1 sec. (4 corner readout)
32 Mbytes/sec

3. Quantum 210

4. 18 Quantum 210 detectors delivered 2001 - 2008

5. Now that we had faster image readout we wanted still bigger detector area

6. The Quantum 315 uses 9 instead of 4 of exactly the
same modules as used in the Quantum 210.
315 mm
210mm
210 mm
315 mm
Quantum 210
4K by 4K
Quantum 315
6K by 6K

7. CAD drawing of Quantum 315

8. Quantum 315 at SSRL

9. Quantum 315 diffraction image
Bacterial Ribosome
Jamie Cate and
Jonas Noeske
James Holton’s
Beamline 8-3-1
At the ALS

10. Diffraction pattern from a Quantum 315
Early Image Plate
(MAR 180)
ADSC multiwire
Counter system
Single counter
diffractometer

11. We delivered 32 Quantum 315 detectors 2001-2012

12. But especially for the new brighter synchrotrons being built we need detectors that have even faster readout and much larger dynamic range than CCD detectors have.

13. Pixel Array Detectors are now becoming the dominant X-ray detector technology at synchrotrons

14. Basic Structure of Pixel Array Detectors
Diode detection layer
Direct x-ray conversion
in fully depleted
high resistivity silicon
X-ray
~3200 e- / 12keV x-ray
Connecting Bumps
1 per pixel
Solder
CMOS electronics:
pixel signal processing,
frame storage: the
“ASIC”.

16. Pixel Array Detectors: Important Features
Direct detection of X-rays: High efficiency with low noise contribution.
Each pixel has detection logic and
counters and/or integrators built in.
The ASIC signal processing layer can be built
efficiently in 2cm by 2cm size and
larger areas can be built using tiled modules.

17. … And more Very fast readout time (~1 millisecond).
High Frame rates (~1khz or higher) are possible.
Shutter-less data collection for crystallography!
Extremely high Dynamic Range (ability to record
very strong and very weak data simultaneously).
Sub pixel point spread.
Weak signals are not affected by a neighboring
pixel’s strong signal.
Flexible pixel design allows for detectors to be customized for specific scientific applications.

18. But Pixel Array Detectors do have Gaps…
Control and data lines must be attached to bonding pads along one side of the ASIC.
So All larger multi-module PAD detectors have small
dead spaces (gaps) between the modules.

19. PILATUS at Swiss Light Source
Pixel
Array
Detector
Showing
Gaps

20. ASIC : Application Specific Integrated Circuit
ASIC : Application Specific Integrated Circuit ASIC’s are custom designed silicon chips
There are three basic kinds of signal processing ASIC’s in pixel array detectors
Charge Integrating
Photon Counting
Charge Ramp Counting

21. Charge Integrating Pixel
X-rays incident on
a single pixel
+150 V
Diode
layer +
Electric charge
- voltage
Solder
Bump
digitize
voltage
accumulated
on capacitor
( CHESS/LCLS )
CMOS
layer
Reset
exposure time

22. Charge Integrating Pixel
Advantages
Simplicity of design
No pulse height thresholds to adjust
Purely analog so usable at 4th generation pulsed X-ray sources
with extremely high instantaneous flux
Disadvantages
Capacitor fills up with charge after about 10^4 12kev X-rays
so limited dynamic range

23. The Photon Counting Pixel
X-rays incident on
a single pixel
+150 V
Diode
layer +
1 pulse
per X-ray
Read contents
of counter after
exposure time
Solder
Bump
CMOS
layer
Amplifier and
shaper
Pulse height
Discriminator

24. X-ray Photon (Pulse) Counting
Advantages
Simplicity of design
Room temperature operation
Some energy resolution
Disadvantages
Count rate limitations
Pulse height thresholds need to be reset for each different X-ray energy

25. The Charge Ramp Counting Pixel
There is a better solution to higher count rates
than a simple counting pixel:
The Charge Ramp Counting Pixel

26. The Charge Ramp Counting Pixel
+150 V
At end of exposure time
1. read contents of
ramp counter (18 bits)
Diode
layer
- voltage
V thresh
2. digitize the final
partial ramp
(10 bits)
Solder
Bump
Comparator
exposure time
Buffer
amplifier
CMOS
layer
V thresh 1
Precision
Charge Removal

27. The main advantage of the
Charge Ramp Counting Pixel is that
It can accurately measure up to
100 million X-rays / pixel / second
With no co-incidence counting loss.

28. But at low count rates
-- less than 100,000 X-rays/pixel/sec
where co-incidence loss
is not a problem….
counting individual x-rays
will probably give
superior measurement accuracy
and can allow some energy resolution

29. Can we have it all ?
Very high effective count rate in the
bright parts of the diffraction pattern
and
The ultimate accuracy of counting X-rays
in the weaker parts of the diffraction
pattern

30. We are developing an ASIC with
pixels which can be configured into either of the two modes.
We call these pixels
“Dual Mode” pixels.

31. The Dual Mode Pixel in X-ray Pulse Counting Mode
+150 V
X-rays
Diode
layer
22 bit
counter
Solder
bump
Charge sensitive
amplifier
Shaper
Pixel threshold
Comparator
CMOS
layer
Slow
amplifier
Comparator 1
Global threshold
Multiplexer
10 bit A/D
Precision
charge removal
Sample
& Hold

32. The Dual Mode Pixel in Charge Ramp Counting Mode
+150 V
X-rays
Diode
layer
22 bit
ramp counter
Solder
bump
Charge sensitive
amplifier
Pulse from
One charge ramp
Shaper
Comparator
Pixel threshold
CMOS
layer
Slow
amplifier
Comparator 1
Ramp threshold
Multiplexer
10 bit A/D
Precision
charge removal 1 1
Sample
& Hold
=32 bit intensity data

33. We have just completed testing of the 16 by 128 pixel version of the dual mode ASIC and are ready to submit a foundry run for the full sized 128 by 128 pixel production version

34. The first proof of principle detector we will build with this new ASIC will be the 512 by 512 pixel HF-262k to be delivered to NSLS beamline 4A about November of this year
ACA 1 August 2012

35. The scheduling of the NYSBC contract requires delivery of the 2K by 2K HF-4M detector to X4A at the NSLS by late summer of 2013
150 micron pixels
328 mm by 308 mm
active area
3mm horizontal gaps
100 Hz frame rate
ACA 1 August 2012

36. The Dual Mode PAD Detector
4 by 16 array of 128 x 512 pixel modules
X-ray Photon Counting Mode
can be set for the pixels in the weaker parts of the diffraction for best statistics
Charge Ramp Counting Mode
Can be set in central pixels for measuring high intensity, low resolution diffraction spots without saturation.

37. What a change in the last 40 years !
In 1970 a protein data set could take weeks to collect using film or a diffractometer with a single point counter
With the pixel array technology being developed now, accurate protein data sets can be collected in just a few seconds !

38. Special acknowledgment to the Many people who contributed to the early work on the multiwire diffractometer systems at UC San Diego
Xuong lab: Chris Nielsen, Carl Cork, Andy Howard, Dan Anderson, Don Sullivan
Physics Dept: Wayne Vernon
Chemistry Dept: Joe Kraut, Dave Matthews,
Karl Voltz, Jeff Bolin, Tom Poulos