Development of the X-ray Detectors for XTP Cao Xue-lei Institute of High Energy Physics, CAS 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 channels for the hard X-ray collimated telescope. Collimator Telescope Unit1 (ADC, FPGA, HV) Unit2 (ADC, FPGA, HV) Unit3 (ADC, FPGA, HV) …. Module-1 16-ch ASIC CZT detector and PreA -1 CZT detector and PreA -2 CZT detector and PreA -3 CZT detector and PreA -16 …. Module-2 16 –ch ASIC Module-3 16-ch ASIC …. Module ch ASIC Unit25 (ADC, FPGA, HV)

Characteristics of the High energy X-ray Collimating Telescope FOV ： 1°×1° 。 Active area ： 2500 cm Detector ： CZT Energy resolution ： FWHM Time resolution ： 200μs Energy coverage ： 8-100keV Single detector size: 5mm*5mm*2mm Total number of the DET: Total mass: ~200kg Power dissipation: ~200W CZT detectors Front-to-end electronics Collimator

Characteristics Prototype (From to ) of the Collimator Detectors DetectorsCZT Single detector size5mm*5mm*2mm Number of detectors192 Energy resolution FWHM -10 Time resolution200µs Power dissipation45W

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. Thickness (mm) Efficiency The CZT Crystal and the electrode preparation CZT detectors with different size Pixels electrodes Spectrums of the CZT detector Vs scintillator Spectrum of the LaBr 3 CZT has better energy resolution than LaBr 3

CZT detectors for the prototype

Test of the CZT chips code Volt-Ampere characteristic Am-241 source test -100v (nA) 100v (nA) -200v (nA) 200v (nA) -300v (nA) 300v (nA) V Energy resolution v4.68% v4.89% v5.30% v5.55% v6.37% v6.47% Size ： 5mm×5mm×2mm >200 pieces have already made

Performance of the CZT detector Single channel readout system of the CZT detector Spectrum of the Am-241 source used the CZT detector prototype Functional block diagram of the prototype Energy resolution ： FWHM 。 CZT detector size ： 5mm*5mm*1mm Temperature ： 23 ℃， Humidity ： 18% Preamplifier CZT HV Power Amplifier MCA

The Chips made in IHEP Include three parts: Pre-Amplifier, Amplifier, Comparator and Peak-Holder Some results of the readout chips 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

The test board for the readout chips Pre- Amp Si-Detector Am p Comparator and Peak-Holder power

Bonding wire for Pre-Amp

Simulated result Result from the test board Input signals, blue Signal from the preamp （ red ） Signals from the amplifiers （ green ） Peak holding signals

Test with the Si-PIN detector Detector and Pre-Amplifier connect by bonding wire directly 5mm 2 Si － PIN detector Am-241 radioactive source Commercial MCA room temperature FWHM is V

A Single-channel test board for CZT with readout chips

Nine-channel prototype 9 CZT detectors with the size of 5mm*5mm*2mm Nine channels wire bonded-chip

Spectrum of the Am-241 of the 9-channel prototype Energy resolution about FWHM

ASIC for CZT pixel detectors Type: VA32TA6 Made by: Ideas company Power: <1mW /Channel Channel: 32 Noise: e/pF ADC: 10 bit SEL : 18 MeV Process: 0.35 um N-well CMOS VA32TA6 are Used in HXMT ME telescope The VA-TA principle The architecture of VA parts

Some tests on the VA32TA6 A prototype of the Si-PIN with the VA32TA6 Arrival time intervals(us) Counts Spectrum of the Am-241 source by the 6mm 2 Si-PIN with the VA32TA6 ASIC, with the energy resolution of FWHM keV This fig shows the arrival time interval distribution of the VA32TA6 prototype. The dead time is shorter than 180 us.

SEU/SEL test Single event test in the tandem accelerator line. The single particle lock threshold is about 18 MeV.cm 2 /mg Experiment with VA32TA6 work in the temperature -50 ℃, 14 days Electrostatics discharge test of the VA32TA6, it is very impressible for the ESD, <50V

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 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 -40 Time resolution 20µs Power 35W

SPD detectors Pixel size ： mm 2 Thickness ： 300μm-2mm Pixel structure : P-I-N Superiority ： 1 ） High detection efficiency in keV, 2 ） Good energy resolution ， FWHM ； 3 ） Acceptable spatial resolution: 300μm-3mm ； 4 ） High time resolution ， <1us

SPD chips The 100 pixels SPD packaged on PCB The leakage current of SPD in +25 ℃ Parameters of the SPD  Pixel size ： 1mm*1mm  Thickness ： 500um  Pixel number ： 10*10  Leakage current ： < 0.4nA depleted The first prototype

The Prototype Based on the SPD SPD prototype block diagramThe 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 Am-241 source spectrum of one pixel, temperature 21 ℃, Results ：  Energy resolution: FWHM at room temperature  Dead time ： 20us

Si-PIN 探测器低温测试 Temperature control system in vacuum, for SPD detector test Peltier device Results ： Si-PIN pixel detector at -15 ℃， for the Am- 241 source, the energy resolution, FWHM The spectrum of the Am-241 used SPD, in -15 ℃

7-channel SDD detectors(2010) 7 SDD detectors. Active area 1cm^2 FWHM -35 ℃

Summary SDD and SPD is suitable for the low energy X-ray focal plane detector, the energy resolution better than FWHM The high energy collimated telescope uses the CZT detectors, it has an active area of 2500 cm 2, and the energy resolution is better than The CZT pixel detectors are used for the HE focal plane detectors. The energy resolution should better than 2