1. Brief Overview of China’s Future Space X-ray Astronomy Program
Shuang-Nan Zhang Center for Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences

2. Outline Approved missions: launch within the next 5 years
Hard X-ray Modulation Telescope (HXMT)
Space Variable Object Monitor (SVOM): China-France collaboration (Barret’s Talk)
Gamma-ray burst polarimeter (POLAR): China-Europe collaboration on China’s Spacelab
In mission definition and technology development phase: launch within next ~10 years
X-ray Timing and Polarization mission (XTP)
Proposed onboard China’s Space Station: launch around
Optical/UV/X-ray All-Sky Monitor

3. HXMT is a collaboration between:
Payload Cabin
Platform Cabin
HXMT is a collaboration between:
Chinese Academy of Sciences, Tsinghua University
Chinese Academy of Space Technology

4. HE: NaI/CsI 5000 cm2 LE:SCD,384 cm2 ME:Si-PIN,952 cm2
Payloads onboard HXMT
Size：1900×1600×1000 mm3

5. LE
The Sun
A sunshading board will be set so that the LE and ME instruments can work at low temperatures

6. High Energy X-ray Instrument
1、其中NaI（Tl）作为主探测介质，而CsI（Na）在Na(Tl)的后面，屏蔽2π方向分本底
反符合屏蔽探测器是覆盖在主探测器顶部和周围的塑料闪烁体探测器，其目的是消除空间高能带电粒子在主探测器上形成的本底，提高探测灵敏度。
2、监测器系统，检测探测器接收的光子流强。当流强超过影响探测器性能的数值时，关闭探测器，使探测器停止工作，从而保护探测器；同时，通过分析粒子监视器记录的空间带电粒子流强信息，还可以与空间环境监测器SEM的数据结合，估计望远镜的本底水平。
3、实时跟踪并标定主探测器的工作情况，特别是测量稳定性情况，以便随后对主探测信号的校正或实现主探测器系统的自动增益校正。
bicrystal
scintillation detector, and the effective area is 5000cm2. The whole telescope is divided
into 18 modules with the same size of field of view 1.1◦×5.7◦ (FWHM). They are arranged
to deflect successively from the normal direction of the collimator by an increment of 10◦.
The pointing of every module is fixed by the upper, middle and lower pallets. The top and
side surfaces are all attached with 6 pieces of charged-particle anticoincidence plates. Fig.13
shows the layout of the whole 18 modules of HE, and Fig.14 shows the overall structure of
the effective payload of HE.
HXMT/HE Components assembly
The 18 main collimated phoswich detectors
Charged-particle anticoincidence plates (6 pieces up side +12 lateral side)
Particle Monitor detectors
Calibration detectors (automatic gain control)

7. The Field of View configuration of HE
1 Blind Module
2 Modules of
5.7 °× 5.7 °
15 Modules of
1.1 ° × 5.7 °
高能X射线望远镜总体结构图（上）及主探测器示意图（下）
1、其中NaI（Tl）作为主探测介质，而CsI（Na）在Na(Tl)的后面，屏蔽2π方向分本底
反符合屏蔽探测器是覆盖在主探测器顶部和周围的塑料闪烁体探测器，其目的是消除空间高能带电粒子在主探测器上形成的本底，提高探测灵敏度。
2、监测器系统，检测探测器接收的光子流强。当流强超过影响探测器性能的数值时，关闭探测器，使探测器停止工作，从而保护探测器；同时，通过分析粒子监视器记录的空间带电粒子流强信息，还可以与空间环境监测器SEM的数据结合，估计望远镜的本底水平。
3、实时跟踪并标定主探测器的工作情况，特别是测量稳定性情况，以便随后对主探测信号的校正或实现主探测器系统的自动增益校正。
bicrystal
scintillation detector, and the effective area is 5000cm2. The whole telescope is divided
into 18 modules with the same size of field of view 1.1◦×5.7◦ (FWHM). They are arranged
to deflect successively from the normal direction of the collimator by an increment of 10◦.
The pointing of every module is fixed by the upper, middle and lower pallets. The top and
side surfaces are all attached with 6 pieces of charged-particle anticoincidence plates. Fig.13
shows the layout of the whole 18 modules of HE, and Fig.14 shows the overall structure of
the effective payload of HE.

8. (radiator)
An ME detector box

9. Detector: Si-PIN
Energy coverage: keV
Detecting area: ~950 cm2 (1728 pixels)
Sensitivity: mCrab
Field of view: °×4°,4 °×4°, blind field
Energy resolution: < 1.5
Work temperature: -20~-40℃ for Si-PIN
Time resolution: μs
Mass: kg
Power dissipation: W
16 Si-PIN (0.56 cm2 each) pixels will be in one package and 2 packages read by a RENA-3 asic.

10. The low energy instrument (LE)
2×2
CCD236
16 cm2

11. The Hard X-ray Modulation Telescope @ EAMA-7
FOVs of an LE module
The Hard X-ray Modulation EAMA-7

12. Schematic map of a CCD236 (e2v)
Detector: SCD
Energy coverage: keV
Detecting area: ~384 cm2 (96 chips)
Sensitivity: mCrab
Field of view: °×6°,4 °×6°, blind field
60 °×3°(48cm2),
Energy resolution: <150
Work temperature: -40~-80℃ for SCD
Time resolution: ms
Mass: kg
Power dissipation: W
Schematic map of a CCD236 (e2v)

13. Characteristics of the HXMT Mission
Detectors
LE: SCD, 384 cm2;ME : Si-PIN, 952 cm2
HE : NaI/CsI, 5000 cm2
Energy Range
LE: 1-15 keV;ME: 5-30 keV;HE: keV
Time Resolution
HE: 25μs; ME: 20μs;LE: 1ms
Energy Resolution
LE: 6 keV
ME: 17.8 keV
HE: 60 keV
Field of View of one module
LE: 6°×1.5°; 6°×4°; 60°×3°; blind;
ME: 4°×1°; 4°×4°; blind;
HE: 5.7°×1.1°; 5.7°×5.7°；blind
Source Location
<1' (20σ source)

14. Sensitivity (3σ, in 105s)
LE: 4.4×10-5 cts cm-2s-1 keV–1
ME: 2.6×10-5 cts cm-2s-1 keV–1
HE: 3×10-7 cts cm-2s-1 keV–1
Orbit
Altitude: ~550 km ; Inclination: ~43°
Attitude
Three-axis stabilized
Control precision: ±0.1°
Measurement accuracy: ±0.01°
Data Rate
LE: 3 Mbps; ME: 3 Mbps; HE: 300 kbps
Payload Mass
~1000 kg
Nominal Lifetime
4 years
Working Mode
Scan survey, pointed observation

15. Scientific objectives of pointed observations
X-ray Binaries
Broadband X-ray variability, especially the QPO properties of BH binaries at energy higher than 20 keV;
Broadband spectral characteristics and state transitions
Cyclotron Resonance Features (CRF) close to the neutron star surface;
Broadband spectrum of bright AGN: reflecting components and high energy cut off;

16. Observation modes Scanning Sky Survey mode
Deep scanning observations of selected sky regions (such as the Galactic center region)
Pointed observations
The requirements of ADCS is based on HXMT mission objectives. In order to fulfill the objectives, the HXMT mission is divided into several mission phase. For every phase, a survey mode is defined.
There are two main mission phases and two corresponding survey mode:
The first is all sky scan phase .In this mode, the attitude of HXMT satellite is 3-axis stablized and earth oriented. The all-sky survey is carried through the motion of the satellite in its orbit and precession of the orbital plane. By rotating about the roll axis by thirty degrees and minus thirty degrees , HXMT is able to cover most sky region. This scan phase will take six months to complete.
The second phase is pointing and deep scanning of selected sky region. The satellite will operate in inertial fixed attitude to stare the interested sky region. For each point in the sky region, the period of attitude stablization is thirty minutes.Then the satellite is maneuvered to observe next point. This phase will run through the rest of mission lifetime ,about eigthteen months.

17. Status of HXMT Full-funding decision: March 2011
Phase-B (pre-flight module):
Phase-C (flight module):
Launch: ~2015

18. Outline Approved missions: launch within the next 5 years
Hard X-ray Modulation Telescope (HXMT)
Space Variable Object Monitor (SVOM): China-France collaboration (Barret’s Talk)
Gamma-ray burst polarimeter (POLAR): China-Europe collaboration on China’s Spacelab
In mission definition and technology development phase: launch within next ~10 years
X-ray Timing and Polarization mission (XTP)
Proposed onboard China’s Space Station: launch around
Optical/UV/X-ray All-Sky Monitor

19. Gamma-ray burst polarization experiment onboard China’s Spacelab: POLAR
GRB prompt emission polarization: a last observables of GRBs
Different GRB models
E-M Model: well defined, moderate Plin ~ 50%
Fireball Model: high values excluded Plin ~ %
Cannon ball Model: full range possible Plin = %
Probe quantum gravity (???):
Amelino-Camelia G., 2000, Nature, 408, 661
Piran T, 2005, Lect. Notes Phys, 669, 351
Fan, Y-Z; Wei, D-M; Xu, D. 2007, MNRAS, 376, 1857
From M. Lyutikov, 2003
See papers discussing various GRB models: T. Piran, A. Dar, M. Lyutikov, D. Eichler, G. Ghisellini, D. Lazzatti, M. Medvedev, E. Rossi etc. 19

20. Plastic scintillator stacks
Gamma-ray burst polarization experiment onboard China’s Spacelab: POLAR
Onboard China’s spacelab TG-2: launch time
A China-led international collaboration (Switzerland, France, Poland)
FOV of POLAR: ~½ sky
Tian-Gong 天宫
Palace in Heaven
Plastic scintillator stacks
Instrument concept proposed by N. Produit, et al., NIM (2005)

21. POLAR capability summary
10 GRBs per year down to 8%, or
60 GRBs per year down to 30%, or 100 GRBs per year down to 50% polarization,

22. Outline Approved missions: launch within the next 5 years
Hard X-ray Modulation Telescope (HXMT)
Space Variable Object Monitor (SVOM): China-France collaboration (Barret’s Talk)
Gamma-ray burst polarimeter (POLAR): China-Europe collaboration on China’s Spacelab
In mission definition and technology development phase: launch within next ~10 years
X-ray Timing and Polarization mission (XTP)
Proposed onboard China’s Space Station: launch around
Optical/UV/X-ray All-Sky Monitor

23. X-ray Timing and Polarization (XTP) mission
Key Science: Matter under extreme conditions
Precise Light curve: Neutron Star equation of state, BH basic parameters, formation and growth …
Polarization of X-ray: Radiation mechanism…
Diffuse X-ray emission, hot gas distribution in Galaxy …
Main Requirement: large effective area & high counting rate
The most accurate light curve and polarization observation at 1-30 keV

24. HERO concept: High Energy Replicated Optics – Small Aperture, Short Focal Length and Shallow Grazing Incidence
Using small mirror array to achieve large collection area at hard X-ray (>10 keV): technically more feasible than single large mirror.
Ramsey et al, SPIE 2000

25. Bepicolombo soft X-ray (<10 keV) MPO telescope: short focal length & lightweight 25

26. XTP Mission Concept

27. XTP (Possible) Instruments
SDD/CZT
High-energy Collimated Array (1-100 keV)
SDD/CZT
High-energy Focused Array (1-100 keV)
CZT
All Sky Monitor
(5-300 keV)
GEM
Polarization Observation Telescope (2-10 keV)
CCD
Low-energy Focused ( keV)
SCD
Low-energy Collimated Array ( keV)
4 m focal length

28. 有效载荷初步方案 LFA: Low energy X-ray Focusing telescope Array 0.5-10 keV
Micro-pore Optics (MPO) mirrors, mDEPFET detectors

29. High energy X-ray Focusing telescope Array (HFA): 1-100 keV
Double conical nested mirrors
SDD+CZT composite detector

30. Low energy x-ray Collimated detector Array (LCA): 0.5-15 keV
SCD: e2V
LIGA made collimator: 30μm thickness each layer
一个LCA模块示意图

31. HCA composite detector
HCA: High energy X-ray Collimated detector Array keV
HCA composite detector

32. POT: Polarization Observation Telescopes 2-10 keV
GEM-TPC: keV
掠射望远镜可通过国际合作由意大利INAF研制，图示为意大利原为HXMT设计的多层掠射镜的装配图。

33. ASM: All-Sky Monitor
FOV~2Sr, keV, 1000cm2, 6400 × 4mm×4mm CdZnTe

34. XTP Basic Parameters Total satellite mass: 3210 kg
Energy Range, Weight, FOV & Angular Resolution
HFA：1-100 keV, 480 kg, 1°×1°, 1’
LFA： keV, 170 kg, 1°×1°, 1’
HCA：1-100 keV, 500 kg, 2°×2°
LCA： keV, 400 kg, 2°×2°
ASM：4-300 keV, 100 kg, 2 Sr
POT：2-10 keV, 110 kg, 22’ ×22’
Total satellite mass: 3210 kg
Geometrical Area
HFA: cm2 (1-6 keV), 2800 keV
LFA：7400 keV
HCA: cm2 (6-30 keV)
LCA: cm2 (1-6 keV)
Energy Resolution
150 keV
4 keV
Timing Resolution
10 μs
May choose near-earth orbit or L2 orbit, depending on available launcher (money)

35. Outline Approved missions: launch within the next 5 years
Hard X-ray Modulation Telescope (HXMT)
Space Variable Object Monitor (SVOM): China-France collaboration (Barret’s Talk)
Gamma-ray burst polarimeter (POLAR): China-Europe collaboration on China’s Spacelab
In mission definition and technology development phase: launch within next ~10 years
X-ray Timing and Polarization mission (XTP)
Proposed onboard China’s Space Station: launch around
Optical/UV/X-ray All-Sky Monitor

36. OUVX-ASM Mission Concept
zenith
One X-ray ASM Module
Motion of spacecraft
FOV of OUV-ASM
FOV of X-ASM

37. Summary on China’s Future Space X-ray Astronomy Program
Approved missions
Hard X-ray Modulation Telescope (HXMT):
Space Variable Object Monitor (SVOM): China-France collaboration (Barret’s Talk) ~2015
Gamma-ray burst polarimeter (POLAR): China-Europe collaboration on China’s Spacelab
In mission definition and technology development phase
X-ray Timing and Polarization mission (XTP) ~2020
Proposed onboard China’s Space Station
Optical/UV/X-ray All-Sky Monitor ~