CTAデュアルミラー光学系用焦点面検出器の試作器開発
Hiro Tajima, Akira Okumura, Naoya Hidaka, Takanori Kawashima
Solar-Terrestrial Environment Laboratory, Nagoya University
Stefan Funk, Leonid Sapozhnikov, Luigi Tibaldo
SLAC National Accelerator Laboratory
Kavli Institute for Particle Astrophysics and Cosmology
Justin Vandenbroucke
University of Wisconsin, Madison
Richard White, Jim Hinton
Department of Physics and Astronomy, University of Leicester

September 20, 2013
JPS meeting高知Cherenkov Telescope Array❖ Observations of gamma rays in 20 GeV – 100 TeV band✤ Cherenkov light from electromagnetic shower produced by interaction ofgamma rays with atmosphere❖ Large collection area by placing many telescopes✤ x10 better sensitivity❖ Wide energy band coverage by three different size of telescopes✤ Large-size telescope (LST): Φ = 23 m, 20 GeV – 1 TeV, 4 telescopes✤ Medium-size telescope (MST): Φ = 10 – 12 m, 0.1 – 10 TeV, ~20 telescopes✤ Small-size telescope (SST): Φ = 4 – 7 m, 1 – 100 TeV, 30 – 70 telescopes
SST
4–7m
LST
23 m
MST
10 – 12 m
CTAデュアルミラー光学系用焦点面検出器の試作器開発
JPS meeting, SEP 20, 2013, 高知

2 /10SC-MST/SST Design Concept❖ Dual mirror design with small pixel photon sensor✤ Small pixel (~6 mm) photon sensor to reduce camera cost
✦ Multi-anode photomultiplier or SiPM
✦ High density readout electronics (ASIC)✤ Schwarzschild-Couder (SC) optics✦ Short focal length to realize small plate scale• Technically challenging✦ Large field of view
• Longer telescope spacing(larger collection area)
cameraSC-MST
0.1~10 TeV~4 m~10 m

cameraSC-SST
1~100 TeV

CTAデュアルミラー光学系用焦点面検出器の試作器開発
JPS meeting, SEP 20, 2013, 高知

3 /10SC-SST Camera Design❖ SC-SST camera parameters
32 modFOV for 0.18°/pixel (36 mm/°)

8.6°

FOV for 0.28°/pixel (23 mm/°)

13.4°

Angular pixel size for FOV=10°

0.21°# of pixels per camera

2,048Power consumption per camera (FE)350 W

Weight per camera (FE+SiPM)

11 kg

Total cost (FE+SiPM) for 50 CAMs*$7.2M*Assuming $20/ch, which does not explicitly include laborfor mechanical module assembly and calibrations~31 cm9°
32 modules
2048 channels

Front-End (FE) electronics module
CTAデュアルミラー光学系用焦点面検出器の試作器開発
JPS meeting, SEP 20, 2013, 高知

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SC-MST Camera Design❖ SC-MST camera parameters
FOV

8.0°

Angular pixel size

0.067°# of pixels per camera

11,328

Power consumption per camera (FE)2000 W

Weight per camera (FE+SiPM)

61 kg

Total cost (FE+SiPM) for 50 CAMs*$24M*Assuming $20/ch, which does not
explicitly include labor for mechanicalmodule assembly and calibrations

25 modules

13 modules

Analog Pixel (0.067 )Triggerpixel
Trigger
Pixel (2 2)Analog pixel

780 mm, 8.04 deg

260 mm, 2.68780 mm, 8.04

CameraModule (8 8)H8500 MAPM (177)~78 cm
8.0°
177 modules
11k channels

Trigger subfield
Subfield
Backplane(5 5 Camera Modules)

6.125 mm, 0.067 deg

CTAデュアルミラー光学系用焦点面検出器の試作器開発
JPS meeting, SEP 20, 2013, 高知

52 mm, 0.578 deg
260 mm, 2.68 deg

5 /10Comparison with Existing Cherenkov Camera
H.E.S.S. camera

SC-MST camera
25 modules

13 modules

Analog
Triggerpixel
Trigger

Analog pixel

780 mm, 8.04 deg

260 mm, 2.68

780 mm, 8.04

Camer
H8500 MAPM

~78 cm8.0°

Trigger subfield
SubfieldBa(5 5 Came

130 cm
5°

177 modules11k pixels
0.064° (6.2 mm)/pixel
6.125 mm, 0.067 deg

52 mm, 0.578 deg

60 modules
960 pixels (PMTs)
0.16° (28 mm)/pixel

CTAデュアルミラー光学系用焦点面検出器の試作器開発
JPS meeting, SEP 20, 2013, 高知

260 mm, 2.68 deg

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SC Camera Front-End Electronics❖ Board configuration✤ Photosensor I/F board: preamp, high voltage (HV), Peltier control✤ Signal processing board: TARGET ASIC, FPGA, back-end I/F, power suuply❖ Minimize # of components for cost reduction and reliability✤ Integration of necessary functionalities into an ASIC

designed by G. Varner(Hawaii)
CTAデュアルミラー光学系用焦点面検出器の試作器開発
JPS meeting, SEP 20, 2013, 高知

7 /10

SC Camera Front-End Electronics❖ Board configuration✤ Photosensor I/F board: preamp, high voltage (HV), Peltier control✤ Signal processing board: TARGET ASIC, FPGA, back-end I/F, power suuply❖ Minimize # of components for cost reduction and reliability✤ Integration of necessary functionalities into an ASIC

32 cm

4.2 cm

HV control

HV
Preamp Vped DAC

PreampTARGET ASIC

ADCFPGA
designed by G. Varner(Hawaii)
CTAデュアルミラー光学系用焦点面検出器の試作器開発
JPS meeting, SEP 20, 2013, 高知

Peltier Control
DC/DC

Flash7 /10

SC Camera Front-End Electronics❖ Board configuration✤ Photosensor I/F board: preamp, high voltage (HV), Peltier control✤ Signal processing board: TARGET ASIC, FPGA, back-end I/F, power suuply❖ Minimize # of components for cost reduction and reliability✤ Integration of necessary functionalities into an ASIC

32 cm

4.2 cm

HV control

HVPreamp Vped DAC

PreampTARGET ASIC

ADC

FPGA
designed by G. Varner(Hawaii)
CTAデュアルミラー光学系用焦点面検出器の試作器開発
JPS meeting, SEP 20, 2013, 高知

Peltier Control
DC/DC

Flash

7 /10

FEE Function Diagram

Preamp
Photo-detectors

SiPM bias
Peltier control

TARGETFPGATrigger
Slow control

DC/DCPreAmp/Powerboard

CTAデュアルミラー光学系用焦点面検出器の試作器開発
JPS meeting, SEP 20, 2013, 高知

L0 trigger x16
Data

Backplane

12 V

Signal Processing
board

8 /10

SC Camera Electronics Design❖ Requirements✤ Waveform sampling at ~ 1 GSa/s✤ Signal bandwidth > 380 MHz✤ Cross-talk < 1%
✤ Look-back time: > 12 µs✤ Dynamic range: > 9 bits
✤ Readout (dead) time: < 30 µs✤ Trigger timing: < 4 ns
✤ Trigger segment: 0.1° x 0.1° ~ 0.2° x 0.2°

❖ TARGET ASIC
✤ Switched capacitor array for high speed waveform sampling✤ Integrated digitization circuits and trigger circuits✦ Reduction of components and cost, increase reliability✤ Internal bias generator✦ All digital interface✤ Low power consumption: ~70 mW/channel including FPGACTAデュアルミラー光学系用焦点面検出器の試作器開発
JPS meeting, SEP 20, 2013, 高知

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History of TARGET development❖ TARGET-1✤ 2008/May delivery✤ BW is limited to ~150 MHz, 8k cells, no analog sum trigger❖ TARGET-2/TARGET-4✤ 2011/Aug (TARGET-2), 2012/Feb (TARGET-4)✤ Improved BW and cross talk, 16k cells, more (faster) digitization
circuits, 4-ch analog sum trigger✤ Problem with serial register loading, DAC voltage routing❖ TARGET-5✤ 2012/Aug delivery✤ BW is confirmed up to 400 MHz, cross talk < 1%
✤ Minimum trigger threshold is too high (~25 mV, ~6 p.e.)❖ TARGET-7✤ 2013/Sep submission, Dec delivery (expected)✤ Wider dynamic range, better linearity and better temperaturestability✤ Lower trigger threshold (<10 mV, 2.5 p.e.)CTAデュアルミラー光学系用焦点面検出器の試作器開発
JPS meeting, SEP 20, 2013, 高知

10 /10TARGET-7 Specifications
TARGET-5# of channels

TARGET-7
161616,384

16,3840.4 – 1.2 GHz

0.5, 1.0 GHz> 380 MHz> 380 MHz

< 1%

< 1%

0.6–1.0 mV/1.5 V

0.6–1.0 mV/2 V~700 MHz~500 MHz (external, both edges)

5.9 µs (12 bit)

8.2 µs (12 bit)# of cells/digitization

32 cells x 16 ch

32 cells x 16 ch

Data transfer speed~90 Mbps x 16 ch~90 Mbps x 16 ch# of cells/channel
Sampling frequency
Bandwidth
Crosstalk (@ -3dB)
Dynamic range
Wilkinson ADC clock speed
Digitization time

Dead time

10 bit2.9 + 8 µs

4.1 + 8 µs

(48 cells/ch)

12 bit11.7 + 8 µs

16.4 + 8 µs

4 (4 ch analog sum)+ 1 (16 ch analog sum)4 (4 ch analog sum,no gain adjustment)# of trigger output
Trigger threshold at input

25 mV minimum

10 – 80 mV (2.5 – 20 p.e. for MST)
0.2 mV step (nominal, 0.05 p.e. for MST)

Trigger threshold noise< 4 mV< 1.6 mV (rms)

Trigger gain adjustment

20%None

CTAデュアルミラー光学系用焦点面検出器の試作器開発
JPS meeting, SEP 20, 2013, 高知

11 /10SC-SST/SC-MST Prototype Development❖ SC-MST prototype✤ Partially populated mirrors and SiPM camera modules✦ Comprehensive study of the structure, mirrors, motorization andcontrol system❖ SC-SST prototype✤ Mini-array: 5 complete telescopes and cameras✦ 1 MAPM camera + 4 SiPM cameras✤ Test array performance, conduct scientific observations
2013
Q4SC-SST

SC-MST

32x
MAPM
modules

Q1

2014
Q2
Q3

MAPM camera
assemblylab test32x SiPM SiPM camera
modules assembly
SiPM25x SiPM
cameralab test
modules
assembly
CTAデュアルミラー光学系用焦点面検出器の試作器開発
JPS meeting, SEP 20, 2013, 高知Q4

Q1

2015
Q2
Q3

Q4

field test
Mini-arraylab test

field test

field test
12 /10Summary and Plans❖ Waveform sampling capability of TARGET-5 is satisfactory✤ Trigger performance will be fixed by TARGET-7 with better
dynamic range and linearity❖ Characterization and improvement of SiPM ongoing
22pSD7: 日高直哉

「CTA計画 半導体光検出器MPPCを用いたチェレンコフカメラの開発」❖ Plans✤ TARGET-7 will be submitted for fabrication in 2013/Sep✤ Prototype production started✦ SC-SST mini-array✦ SC-MST partial telescope

CTAデュアルミラー光学系用焦点面検出器の試作器開発
JPS meeting, SEP 20, 2013, 高知

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