Cryogenic detector systems:recent work.
M.BorriDaresbury Laboratory
UKRI-STFC
Outline:
• Photon-science: XH for x-rays and mid-IR∗.
• Nuclear physics: Prospectus.
• Conclusion.∗ not Ge sensor.
See also BEGe cryostatI.Lazarus @ AGATA WeekMilan, 2017.
ESRF-ID24 upgrade.
• Extremely Brilliant Source ESRF: new lattice.
• ID24 refurbished to High Power Laser Facility (HPLF).
• Coupling 100J ns-Laser to 4th Generation Synchrotron.
• Pump-probe experiments in single shot.
• Experimental technique is Energy Dispersive EXAFS(EDE).
• ... And to upgrade XH.
XH system.
• Radiation Harsh Environment:1014 γ/s on Active Area;
• Cryostat Unit:Coolant is LN2;Ge Sensor @ T<-170C;Front-End Electronics;Pwr [10-14W] @ T>-40C;
• DAQ Unit:Operated in Atmosphere;FPGA + µProcessor;CTRL, CLK, DATA;
• Upgrade:New Ge Sensors;New Cryostat;
Micro-strip Ge sensors.
• Size: 1024 strips.
• Strip pitch: 50 um with 25um gap.
• Strip length: 5mm.
• Sensor thickness: 1.5mm.
• Two guard-rings.
• Interleaved wire-boning pads.
• Back illuminated.
X3CHIP.
• STFC designed.
• Process: AMS 0.35um.
• Channels: 128.
• Analogue front-end:Charge integration;Charge sampling;
• Analogue output:32 chs per mux;4 mux per ASIC;
DAQ.
• 14bit 50MHz ADC.
• Virtex5 (FX70) FPGA.
• Embedded micro-processor 400MHz.
• 1GByte Ethernet link.
Prototyping: in-beam tests.
0 2 4 6Time [s] 1e 7
0.00
0.25
0.50
0.75
1.00
[a.u
.]
Sensor T~-157C;~7.5x103( @7.5keV)/700ns
Sam
plin
g fo
r:16
bun
ch a
nd 7
/8+1
Vbias-50VVbias-55VVbias-60VVbias-65VVbias-70VVbias-75VVbias-80VVbias-85VVbias-90VVbias-95VVbias-100V
0 2 4 6Time [s] 1e 7
0.00
0.25
0.50
0.75
1.00
[a.u
.]
Sensor T~-157C;V=-100V
Sam
plin
g fo
r:16
bun
ch a
nd 7
/8+1
Vbias=-100V
=7.52e+03( @7.5keV)/700ns=5.26e+03( @7.5keV)/700ns=3.79e+03( @7.5keV)/700ns=2.15e+03( @7.5keV)/700ns=1.11e+03( @7.5keV)/700ns=5.39e+02( @7.5keV)/700ns
• Anticipate shut-down.
• Enable early testing while stilldeveloping new cryostat.
• First assembly:New sensors;Old cryostat;
• Study Q-collection time Vs fill-patern.
• In-beam tests:Q-collection time Vs Voltage;Q-collection time Vs Flux;
Mid-IR system.
• STFC Central Laser Facility.
• Electronic and structural dynamics atquantum level.
• Ultrafast [s]: 10−3-10−15.
• Chemistry, physics and biology.
• Mid-IR detectors with STFC Technology.
• Sensor selection ongoing: not Ge!
Starting point
• XH system: not upgraded cryostat.
• Max 4 XCHIPs to r/o up-to 512 strips.
• Sensor T: -297C (or below?).
• Mod the current design to build ademonstrator.
0.0 2.5 5.0 7.5 10.0 12.5 15.0 17.5Pwr [W]
150
100
50
0
50
T_hb
Brd
[C]
Chassis@RoomT; hdBrd; y=12.3x-154.4
200
190
180
170
160
150
140
130
120
T_cld
Plt &
T_c
ldFn
g [C
]
Chassis@RoomT; cldPlt; y=1.97x-190.2Chassis@RoomT; clFng; y=1.28x-192.8
Study on head-board module.
• 4 XCHIP, pwr [W]: 5-7.
• THB > -40C.
• Increased thermal resistivity.
• Torlon spacer non-linearity becomesdominating factor.
0 1 2 3 4 5 6 7Pwr [W]
160
140
120
100
80
60
40
20
0
T [C
]
Head-board module4x16mm screws; y=15.32x-161.44x14mm screws; y=16.05x-154.63x14mm screws; y=18.05x-135.92x14mm screws; y=19.42x-125.1
Low IR contribution.• Low IR contribution to T.
• No IR-shield installed.
• Heated chassis and checked effect oncomponents.
• To repeat with IR-shield.
10 20 30 40 50 60 70T_chassis [C]
200
190
180
170
160
150
140
130
120
[C]
IR contributionhd-brd; y=0.58x-163.4cld-plt; y=0.11x-191.8cld-fng; y=0.08x-193.8
Prospectus.
• Compton camera.
• Nuclear medicine.
• Low dose diagnostics.
• Single Photon Emission ComputedTomography (SPECT).
• Scatterer and absorber in samecryostat.
• Cryostat characterization ongoing.-Vacuum;-Temperature;
Vacuum tests.• P measured in vessel.
• Comparing P cycles.
• Base-line pressure in vessel.
• LN2 burn-rate @ 0W.
• Next:-TminVsVac;-Pump-speedVsTemp;-TempVsPwr;
0 2 4 6 8 10 12[days]
10 5
10 4
10 3
10 2
10 1
100
[mba
r] At room TNo venting between cycles
Repeated cycles
pumping cycle 0pumping cycle 1outgassing cycle 0outgassing cycle 1
0 5 10 15 20 25 30 35[days]
10 6
10 5
10 4
10 3
10 2
10 1
100
[mba
r] Big spikes during cold periodare due to LN2 refill.
Rem
oved
from
pum
p,st
art c
oolin
g.
Star
t war
m-u
p
Stability
0 2 4 6 8 10[day]
40
45
50
55
60
65
[kg]
Only IR No additional pwr
LN2 brun-rate
y=-2.0x + 61.7y=-2.1x + 61.0y=-2.1x + 60.5
Conclusion.
• Results of the XH system for X-rays.
• T optimisation for a possible demonstrator for Mid-IR.
• Characterisation of Prospectus cryostat.