Transcript the Hard x-ray Detectors Onboard XTP

Development of the X-ray Detectors for XTP
Cao Xue-lei
Institute of High Energy Physics, CAS
2014.02.21 IHEP, Beijing
Outline
 Payload configuration
 Primary design of the HE collimating telescope
 Detector architecture
 Performance of the CZT detectors with the readout chips.
 Development of the Focal Plane Detectors
 Characteristics
 Tests of the SPD
 Performance of the SDD
3
XTP payload configuration
Architecture of Detectors of the Collimator Telescope
• The telescope consists of
lots of modules
• 25 Units
• In each unit there are 25
modules, with the HV
power for the detectors,
the ADC and the FPGA
controllers.
• 25 Modules in one
Unit.
• 16 CZT detectors used
one ASIC for readout in
one module.
• So there are 10000
channels for the hard
X-ray collimated
telescope.
Collimator Telescope
Unit1
(ADC,
FPGA ,
HV)
Module-1
16-ch
ASIC
CZT
detector
and
PreA -1
Unit2
(ADC,
FPGA ,
HV)
Module-2
16 –ch
ASIC
CZT
detector
and
PreA -2
Unit3
(ADC,
FPGA ,
HV)
Module-3
16-ch
ASIC
CZT
detector
and
PreA -3
…. ….
….
Unit25
(ADC,
FPGA ,
HV)
Module-25
16-ch
ASIC
…. ….
CZT
detector
and
PreA -16
Characteristics of the High energy X-ray Collimating Telescope
FOV：1°×1°。
Active area：2500 cm2@30keV
Collimator
Detector：CZT
Energy resolution：
FWHM [email protected]
CZT detectors
Time resolution：200μs
Energy coverage： 8-100keV
Single detector size: 5mm*5mm*2mm
Total number of the DET: 10000
Total mass: ~200kg
Power dissipation: ~200W
Front-to-end
electronics
Characteristics Prototype (From 09-2012 to 07-2015) of the
Collimator Detectors
Detectors
CZT
Single detector size
5mm*5mm*2mm
Number of detectors
192
Energy resolution
FWHM [email protected], -10℃
Time resolution
200µs
Power dissipation
45W
The CZT CrystalCdZnTe晶体与电极制备
and the electrode preparation
The CZT detectors
•
The CZT detectors are made
by the Northwestern
Polytechnical University;
•
The efficiency is about 87%
at 100 keV for a 2mm
thickness CZT.
CZT detectors with
不同尺寸CZT单晶
different size
Spectrums
of the CZT detector Vs scintillator
CZT探测器对不同能量X/γ射线能谱响应
Pixels金属电极
electrodes
1.0
10 KeV
30 KeV
50 KeV
60 KeV
100 KeV
125 KeV
200 KeV
600 KeV
800
1000
5x5x5mm
241
Am @ 59.5 keV
Bias @ 400 V
s
2000
Cs @ 662 keV
400
400
600
800
Channel /numbers
[email protected]
FWHM=1.9%
Bias @ 500 V
s
200
0
0
200
400
200
0
0
1000
0
0
100
200
300
400
500
600
700
200
800
57Co@122
400
600
137Cs@662
keV
4.09%
39.39%
800
Channels
Channel
keV
0.8
600
122KeV
Counts
Counts
Counts
4000
600
RT
137
Co
R:5.46%@122KeV
HV Bias:+400V
Temp:300K
LaBr3探测器
Spectrum
of
the
能谱响应曲线
LaBr3
keV
1000
Efficiency
FWHM=5.6%
6000
3
57
800
8000
吸收率
10000
0.6
0.4
0.2
0.0
0
CZT 探测器的能量分辨率远优于性能最好的LaBr3闪烁体探测器
CZT
has better energy resolution than LaBr3
1
2
3
厚度 / mm
Thickness (mm)
4
5
CZT detectors for the prototype
Test of the CZT chips
Size：5mm×5mm×2mm
>200 pieces have already made
Am-241 source
test
Volt-Ampere characteristic
code
-100v
(nA)
100v
(nA)
-200v
(nA)
200v
(nA)
-300v
(nA)
300v
(nA)
V
Energy
resolution
040502065
-2.03
2.05
-4.06
4.11
-6.13
6.27
350v
4.68%
040502075
-1.29
1.22
-2.47
2.38
-3.62
3.54
350v
4.89%
010502017
-1.41
1.35
-2.79
2.63
-4.18
3.88
500v
5.30%
080502139
-1.05
1.05
-2.12
2.06
-3.21
3.09
400v
5.55%
020502224
-2.81
2.57
-6.12
5.34
-9.77
8.30
300v
6.37%
190502235
-1.44
1.50
-2.93
3.02
-4.46
4.63
400v
6.47%
Performance of the CZT detector
CZT探测器
HV Power
高压
CZT
前置放大电路
Preamplifier
主放大器
Amplifier
多道分析器
MCA
Single channel readout system of the CZT detector
Functional block diagram of the prototype

Energy resolution：FWHM [email protected]。

CZT detector size：5mm*5mm*1mm

Temperature：23 ℃， Humidity ：18%
Spectrum of the Am-241 source used the CZT
detector prototype
Some results of the readout chips
 The Chips made in IHEP
Include three parts: Pre-Amplifier, Amplifier, Comparator
and Peak-Holder
Preamp: Charge-sensitive
amplifiers Resistor -capacitor
feedback
Noise : ENC ~60e ，
for Si
detector, the Cd=0.1pF
Peaking Time：0.3μs,
1μs,
6μs, 12 μ s
Power： ~5 mW/per channel
Input:: +/- signals
Process: 0.35 um N-well CMOS
Si-Detector
Pre-Amp
Amp
Comparator and
Peak-Holder
The test board for the readout chips
power
Bonding wire for Pre-Amp
Simulated result
Input signals, blue
Signal from the preamp（red） Signals from the amplifiers（green）
Peak holding signals
Result from
the test
board
Test with the Si-PIN detector
• Detector and
Pre-Amplifier
connect by
bonding wire
directly
• 5mm2 Si－PIN
detector
• Am-241
radioactive
source
• Commercial MCA
• room temperature
• FWHM is
[email protected]
V
A Single-channel test board for CZT with readout chips
Nine channels wire bonded-chip
Nine-channel prototype
9 CZT detectors with the
size of 5mm*5mm*2mm
Spectrum of the Am-241 of the 9-channel prototype
Energy resolution about FWHM 3KeV @59.5KeV
ASIC for CZT pixel detectors
•
Type: VA32TA6
•
Made by: Ideas company
•
Power: <1mW /Channel
•
Channel: 32
•
Noise: 39+12 e/pF
•
ADC: 10 bit
•
SEL : 18 MeV
•
Process: 0.35 um N-well CMOS
•
VA32TA6 are Used in HXMT ME
The VA-TA principle
telescope
The architecture of VA parts
Some tests on the VA32TA6
Counts
A prototype of the Si-PIN with the VA32TA6
Arrival time intervals(us)
This fig shows the arrival time interval
distribution of the VA32TA6 prototype.
The dead time is shorter than 180 us.
Spectrum of the Am-241 source by the 6mm2
Si-PIN with the VA32TA6 ASIC, with the energy
resolution of FWHM 1 [email protected] keV
SEU/SEL test
Electrostatics discharge test of the
VA32TA6, it is very impressible for the
ESD, <50V
Experiment
with
VA32TA6
work in the
temperature
-50℃, 14
days
Single event test in the tandem
accelerator line. The single
particle lock threshold is about 18
MeV.cm2/mg
Architecture of the Focal Plane Detectors
• 3 focal plane detectors
• 256 pixels CZT detectors are used.
• For one focal plane detectors, 4
64-channels ASIC are used for the
read-out electronics. with the HV
power for the detectors, the ADC
and the FPGA .
16*16 pixel CZT
Pixel size:
1mm*1mm*1mm
Characteristics of the focal plane detectors of the
HE telescope
• Detector：CZT pixel detector
• DET Number：3
• Pixel Number per DET：256
• CZT pixel size：1mm*1mm*1mm
• Power dissipation：~80W
• Energy resolution：FWHM 2keV@20keV
• Time resolution：10us
• Work temperature：-10 ~ +20 ℃
• Energy coverage: 8-30keV
Prototype of LE Focal Plane Detectors based on SPD
Detector
Si-PIN pixel detectors, SPD
Pixel size
1mm*1mm*0.5mm
Number of the pixels
100
Energy resolution
FWHM [email protected], -40℃下
Time resolution
20µs
Power
35W
SPD detectors
Pixel
size：0.1-10mm2
Thickness：300μm-2mm
Pixel structure : P-I-N
Superiority：
1）High detection efficiency in 0.5-30keV,
~90% @15keV;
2）Good energy resolution，FWHM [email protected] ；
3）Acceptable spatial resolution: 300μm-3mm；
4）High time resolution，<1us
SPD chips
Parameters of the SPD
Pixel size：1mm*1mm
Thickness：500um
Pixel number：10*10
Leakage current：< 0.4nA depleted
The first prototype
The 100 pixels SPD packaged on PCB
The leakage current of SPD in +25℃
The Prototype Based on the SPD
SPD prototype block diagram
The testing photo of the SPD
Si-PIN像素探测器样机（３）
The spectrum of the Ａｍ-241 source by the 20 pixels of the SPD
Results：

Energy resolution: FWHM
[email protected], at room temperature
 Dead time：20us
Am-241 source spectrum of one pixel, temperature 21℃,
Si-PIN探测器低温测试
Temperature control system in vacuum, for SPD
detector test
The spectrum of the Am-241 used SPD,
in -15℃
Results：
Si-PIN pixel detector at -15 ℃，for
the Am-241 source, the energy
resolution, FWHM [email protected]
Peltier device
• 7-channel SDD detectors(2010)
7 SDD detectors. Active area 1cm^2
FWHM [email protected] , -35℃
Summary
• SDD and SPD is suitable for the low energy X-ray focal plane
detector, the energy resolution better than FWHM [email protected].
• The high energy collimated telescope uses the CZT detectors, it has
an active area of 2500 cm2, and the energy resolution is better than
[email protected].
• The CZT pixel detectors are used for the HE focal plane detectors.
The energy resolution should better than 2 [email protected] keV.