1. X- and gamma-ray focal plane for future space missions
Polarized
Unpolarized
R. M. Curado da Silva1,2, J. M. Maia1,3, M. Pinto1,2, J. Marques1,4, A. M. F. Trindade1,
N. Simões1,2, M. Moita1, C. Patacas1, E. Caroli5, N. Auricchio5, J. B. Stephen5 , P. Gonçalves1
1Laboratório de Instrumentação e Física Experimental de Partículas, Portugal
2University of Coimbra, Coimbra, Portugal
3Universidade da Beira Interior, Covilhã, Portugal
4Centro de Astrofísica da Universidade do Porto, Portugal
5INAF-IASF-Bologna, Bologna, Italy
Lisbon, April 27th, 2015

2. High energy astrophysics (0.1 – 100 MeV)
Address fundamental questions:
nucleosynthesis in stellar explosions (novae and supernovae);
the origin of cosmic rays;
the laws of physics around neutron stars and black holes;
the active sun or the origin of terrestrial gamma-ray flashes;
development of cosmology and fundamental physics.
Polarimetry in high-energy astrophysics
2 extra observational parameters (angle and degree);
emission production mechanism and object geometry.
Novae SN
SNR
Pulsars

3. High energy astrophysics missions
Ongoing missions: INTEGRAL, SWIFT, Fermi
Past consortia: GRI (2007), DUAL (2010)
Submitted mission proposals (M4 e ESA-China):
ASTROGAM, Solar X-ray Polarimeter, XIPE (X-ray Imaging Polarimetry Explorer)
AHEAD H2020 Project: Activities in the High Energy Astrophysics Domain

4. Compton Polarimetry
Unpolarized Beam
Polarized Beam
100%
75%
25%
50% 

5. Previous polarimetric studies
ESRF, Grenoble, France ~ 99 % polarized radiation
Laue lens sample Cu crystals + CdTe detector →

6. Modulation Q and Relative Efficiency vs. Beam Energy

7. Polarization Degree and Angle
Beam Inclination Effects on Polarization

8. Noise and systematics
Residual modulation
Noise

9. Conclusions & Next Steps
1- Squared CdTe pixel matrix systematics affect performances:
Square pixels generate noticeable residual modulation;
Non-uniformities inside material;
Correction methods proved efficient.
2- Full detector detector surface irradiation:
Validation of analysis techniques for multipixel irradiation ~ 1cm2, unknown scatter pixel;
A small 4×4 proved to be sensitive to polarization level of ~ 30% and angular of < 10°.
3- Further polarimetric analysis:
Polarization angle and degree resolution, wider energy band;
Larger area, pixel size, multiplanar configuration, 3D CdTe detector, gamma-ray focusing.
4- AHEAD H2020 activities:
Contribute to optimize instrument polarimetric performances for next ESA mission calls: M4, ESA-China and ASI.