1. Summary of Key Results from the SLAC ESTB
T-506 Irradiation Study
FCAL Harware Meeting
25 May 2016
Bruce Schumm
UCSC/SCIPP 1

2. Mauro Pivi SLAC, ESTB 2011 Workshop, Page 2
LCLS and ESA
Use pulsed magnets in the beam switchyard to send beam in ESA.
Mauro Pivi SLAC, ESTB 2011 Workshop, Page 2 2

3. Daughter Board Assembly
Pitch adapter, bonds
Sensor
1 inch 3 3

4. 2 X0 pre-radiator; introduces a little divergence in shower
Sensor sample
Not shown: 4 X0 “post radiator” and 8 X0 “backstop”

5. December 2015 Exposure and Summary
December 2015: Long, high-rate exposures of all four Si diode types (5 24hr days of ~20 Mrad/hr)
Sensor Type
Notable Exposures (Mrad)
GaAs 20
SiC 80
Si PF
270, 570
Si NF
300
Si PC
Si NC
290
Red indicates results available; others await evaluation
Operated at GeV at close to 1 nA 5 5

6. Charge Collection Apparatus
Readout: 300 ns
2.3 MeV e- through sensor into scintillator
Sensor +
FE ASIC
DAQ FPGA
with Ethernet 6 6

7. Pulse-height distribution for 150V bias Median pulse height vs. bias
Measurement time
Pulse-height distribution for 150V bias
Mean Pulse Shape
Single-channel readout example for, e.g., N-type float-zone sensor
Readout noise: ~300 electrons (plus system noise we are still addressing)
Median pulse height vs. bias 7 7

8. GaAs Results
20 Mrad 8 8

9. GaAs Charge Collection (21 Mrad Exposure)
VB = 600 V 9 9

10. GaAs Charge Collection (21 Mrad Exposure)
Slice at VB=600 vs. function annealing temp 10 10

11. Compare to Direct Electron Radiation Results (no EM Shower)
A bit better performance than direct result
kGy
Pre-anneal
Post-anneal at room temp
Georgy Shelkov, JINR
1000 kGy = 100 Mrad 11 11

12. SiC Results
80 Mrad
Sensor provided by: Bohumir Zatko, Slovak Institute of Science
4H-SiC crystal geometry 12 12

13. SiC Charge Collection after 80 Mrad
@600 V, ~25% charge collection loss (60C annealing)
80 Mrad Exposure 13 13

14. Si Diode Results 270 Mrad PF 300 Mrad NF
P = p-type bulk
N = n-type bulk
F = Float Zone 14 14

15. PF Charge Collection after 270 Mrad
@600 V, ~20% charge collection loss (60C annealing)
VB = 600 V 15 15

16. Polynomial Fit for Temperature Dependent Current
Sensor area = cm2

17. Power Drawn(Watts) of BeamCal collapsed
T = -7 ˚C
T = 0 ˚C
P_total = W
P_total = W
P_max = mW
P_max = mW
(for single 1mm2 pixel)
(for single 1mm2 pixel)

18. Total Power Draw (Entire BeamCal Instrument)
Operating Temperature (0C)
Total Power Draw (W)
Maximum for 1mm2 Pixel (mW) 15 56 23 7 25 10 11
4.6 -7
4.5
1.9

19. NF Charge Collection after 300 Mrad
@600 V, ~55% charge collection loss (32C annealing) 19 19

20. Sensor area = 0.1 cm2
Temperature  -15 C 20 20

21. BACKUP 21 21

22. P-Type Float-Zone Sensor
Reminder of results for 270 Mrad irradiation (about 3 years exposure) 22 22

23. IV Curves at a few Temperatures
Sensor area = cm2