The Nuclear Compton Telescope (NCT) Project

Hsiang-Kuang Chang

Department of Physics and Institute of AstronomyNational Tsing Hua University

Hsinchu, Taiwan

The Nuclear Compton Telescope (NCT) Project

A prototype for a future High Energy Astrophysics Observatory space mission

主持人 國立清華大學 張祥光共同主持人 國立中央大學 張元翰

NCT-Taiwan

PI: Chang, Hsiang-Kuang (NTHU)Co-PI: Chang, Yuan-Hann (NCU)

NCT-US

PI: Boggs, Steven (UCB)

The NCT CollaborationNCT-TW

NTHU Chang, Hsiang-Kuang Cheung, Kingman* Chiu, Jeng-Lun Kong, Albert* Liang, Jau-ShianNCU Chang, Hui-Hong Chang, Yuan-Hann Chou, Yi* Hong, Wei-Che Hwang, Chorng-Yuan* Liu, Tsong-KaiNTNU Chen, Lin-Wen*NCTU Lin, Guey-Lin*NSPO Lin, Chih-Hsun NUU Chiang, Hsuang-Chang Huang, Ming-Huei Juan, Jui-Hsiang NCKU Chen, Bing-Chih*

NCT-US

UCB Bandstra, Mark Bellm, Eric Boggs, Steven Bowen, Jason Hoberman, Jane McBride, Stephen Wunderer, Cornelia Zoglauer, AndreasLBNL Amman, Mark

* Scientific associates

COMPTEL 1-30 MeV Source Catalog

(Schönfelder et al. 2000)

Unique 0.2-10 MeV Science• nuclear lines• e--e+ annihilation• peak emission for GRBs• polarization

The MeV Universe

Interesting sources include:

* Active Galactic Nuclei (AGN)* supernova remnants (SNRs)* interstellar clouds* galactic black holes and microquasars* gamma-ray pulsars* neutron stars and magnetars* solar flares* terrestrial gamma-ray flashes (TGFs)* gamma-ray bursts (GRBs)

CGRO/COMPTEL INTEGRAL/SPI

Incomingphotons

Liquidscintillators

NaI

The principle of a Compton detector (left panel) and the Compton Nuclear Telescope (NCT, right panel), which consists of 12 cross-strip 3-D germanium detectors.

NCT: basic design

cos1mec2

E

mec2

E E1

Cross Strip 3-D GeD: • 37x37 strips• 2-mm pitch• 16-mm thickness• 84000 mm3 volume• 1 mm3 localization• 1-2 keV spectral resolution

Instrument COMPTEL INTEGRAL/SPI INTEGRAL/IBIS

Energy range 0.8 – 30 MeV 0.02 – 8 MeV 0.015 – 10 MeV

Spectral resolution 5 – 8 % 0.2 % @ 1 MeV 8 % @ 100 keV10 % @ 1 MeV

Angular resolution 1.7 – 4.4 degree 2 degree 12 arcmin

Field of view 1 str 16 degree 8 degree

NCT: basic characteristics

2 cross-strip 3-D GeDs

NCT performance (12 GeDs, 3, 800 ks).

Energy range 0.2–10 MeV

Spectral resolution 0.2–1% FWHM

Field of view (FoV) 4060 FWHM

Angular resolution ~2-3 HPHW

Effective area 5-18 cm2

Narrow line sensitivity (1-2)10-5 cm-2 s-1

Continuum sensitivity ~(1MeV/E)10-4 cm-2 s-1 MeV-1

100% Polarization sensitivity 37 mCrab (0.2-0.5 MeV)

Line Sensitivity

Effective Area

Polarization Sensitivity

Continuum Sensitivity

Performance expectations for the NCT 12-GeD balloon payload

The side view of a future gamma-ray imaging spectrometer (left panel) and 1/4 of the detector array (right panel). The size of the coded mask is about 80 cm x 80 cm. The height from the bottom of the detector array to the code mask is about 60 cm.

HEO: a future satellite mission

Energy range 20 – 100 keV (coded aperture)0.2 – 10 MeV (Compton telescope)

Energy resolution (FWHM) 1 keV (20 – 100 keV)0.2 - 1 % (0.2 – 10 MeV)

Angular resolution 15' (20 – 100 keV)1∘(0.2 – 10 MeV)

Point source localization 2' - 5'

Field of view 25% sky

HEO: a future satellite mission

Unique features of the NCT and the future HEO include:

• compact volume• high sensitivity• capability of polarization measurement

The pioneer of the next generation Compton telescope

• Conventional balloon flight, 6 hours, NM, 2005, 2 GeDs

• Conventional balloon flight, ~ 36 hours, NM, 2009, 10 or 12 GeDs

• Long-duration balloon flight, ~ 2 weeks, Australia, 2010/2011, 12 GeDs

NCT Balloon flight plan

NCT instrument

Nitrogen tank

Germanium detectorBGO shielding

Electronics bay

Balloon control and communication unit

2005 Engineering run

10 GeDs have been integrated

Cryostat integrated with dewar

NCT cradle, 2008/07

GeD

Pre

AM

P

GeD

Pre

AM

P

CardCageCardCagex12CardCage

FlightComputer

ShieldSystem

PowerSystem

x12 GeD

Pre

AM

P Power

Signals

Ethernet

Sign

als Pow

er

The block diagram of the top level NCT DAQ system.

The assembled PreAmp board (flight module) and the shielding cover

Backplane

x1DSP

Board

AnalogBoardAnalog

Boardx8

AnalogBoard

x1HV

Unit

x1LVPSBoard

Ethernet

SYNC/CLK

Veto

28VHV

5V

GeD Signal

Guard

HV ON/OFF

Block diagram of Card Cage System

Top view of Analog board

Mechanical part assembly of Analog board FM

The card cage crate

NCT electronics bay, 2008/07

System Block and Responsibility

Detector

Cryostat

x12 GeDx12 GeDx12

PreAmp

Shielding Detector

x12 CardCage

Analog (Amp/ADC/DAC)

DSP

LVPS HVPS

Power System

Solar Panel

Li-ion Battery

Power CTRL BOX

Power Relay BOX

Flight Computer

SBC

TM/TC Interface

Multi I/O Interface

SSR

Differential GPS

Magnetometer

Ground Support Equipment

Balloon/ NASA Equipment

TAIWAN

US

JOINT

NCU

NUU

NTHU

• Conventional balloon flight, 6 hours, NM, 2005, 2 GeDs

• Conventional balloon flight, ~ 36 hours, NM, 2009, 10 or 12 GeDs

• Long-duration balloon flight, ~ 2 weeks, Australia, 2010, 12 GeDs

NCT Balloon flight plan

HEO Key Science Projects

Gamma-Ray Bursts rapid localization for ground follow up spectra, luminosity polarization

Cosmic Gamma-Ray Survey diffuse nuclear emission diffuse electron-positron annihilation supernova remnants (26Al, 60Fe; 44Ti) point source survey gamma ray pulsars neutron star equation of state

Cosmic Hard X-ray Survey daily all-sky map, transients deep all-sky massive black hole (AGN) survey deep Galactic black hole, neutron star survey

Solar flare spectroscopy flare polarization quiescent emission

NCT can do …

Thank you !