12-20 July 2017
BEXCO
Asia/Seoul timezone
Home > Timetable > Session details > Contribution details

Contribution

BEXCO - Room C(108)

[GA130] HARPO, prototype of a gamma-ray polarimeter: Results of a polarised photon beam test between 1.7 and 74 MeV

Speakers

  • David ATTIÉ

Primary authors

  • David ATTIÉ (IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France)

Co-authors

  • S. AMANO (LASTI, University of Hyôgo, Japan)
  • P. BARON (IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France)
  • D. BAUDUIN (IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France)
  • D. BERNARD (LLR, Ecole Polytechnique, CNRS/IN2P3, Palaiseau, France)
  • P. BRUEL (LLR, Ecole Polytechnique, CNRS/IN2P3, Palaiseau, France)
  • D. CALVET (IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France)
  • P. COLAS (IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France)
  • S. DATÉ (IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France)
  • A. DELBART (IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France)
  • M. FROTIN (LLR, Ecole Polytechnique, CNRS/IN2P3, Palaiseau, France)
  • Y. GEEREBAERT (LLR, Ecole Polytechnique, CNRS/IN2P3, Palaiseau, France)
  • B. GIEBELS (LLR, Ecole Polytechnique, CNRS/IN2P3, Palaiseau, France)
  • D. GÖTZ (IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France, AIM, CEA/DRF-CNRS-Université Paris Diderot, France)
  • P. GROS (LLR, Ecole Polytechnique, CNRS/IN2P3, Palaiseau, France)
  • S. HASHIMOTO (IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France)
  • D. HORAN (LLR, Ecole Polytechnique, CNRS/IN2P3, Palaiseau, France)
  • T. KOTAKA (IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France)
  • M. LOUZIR (LLR, Ecole Polytechnique, CNRS/IN2P3, Palaiseau, France)
  • F. MAGNIETTE (LLR, Ecole Polytechnique, CNRS/IN2P3, Palaiseau, France)
  • Y. MINAMIYAMA (IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France)
  • S. MIYAMOTO (IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France)
  • H. OHKUMA (JASRI/Spring8, Japan)
  • P. POILLEUX (LLR, Ecole Polytechnique, CNRS/IN2P3, Palaiseau, France)
  • I. SEMENIOUK (LLR, Ecole Polytechnique, CNRS/IN2P3, Palaiseau, France)
  • P. SIZUN (IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France)
  • A. TAKEMOTO (LASTI, University of Hyôgo, Japan)
  • M. YAMAGUCHI (LASTI, University of Hyôgo, Japan)
  • R. YONAMINE (IRFU, CEA, Université Paris-Saclay, F-91191 Gif-sur-Yvette, France)
  • S. WANG (LLR, Ecole Polytechnique, CNRS/IN2P3, Palaiseau, France)

Description

Access to the photon polarisation in the 1-100 MeV energy range is a challenge for the next generation of space telescopes. The current telescopes in space are almost blind in this energy range, mainly due to the degradation of the angular resolution of e+e- pair and due to elastic scattering in the matter. Pair-conversion detector technologies as gaseous detectors are a promising alternative to the technologies based on tungsten-converter/thin-sensitive-layer stacks such as COS-B/EGRET/Fermi-LAT, firstly to improve the single-photon angular resolution and secondly for the polarisation information. The use of a time projection chamber (TPC) as a target and a tracking detector will improve by up to one order of magnitude the single-photon angular resolution (0.5° @ 100 MeV) with respect to the Fermi-LAT (5° @ 100 MeV), and by up to a factor of three with respect to what can be expected for silicon detectors (1.0-1.5° @ 100 MeV). With such a good angular resolution, a TPC can close the sensitivity gap at the level of 10^-6 MeV/cm².s) between 3 and 300 MeV despite having e lower sensitive mass. Furthermore, this good single-track angular resolution allows us to measure the linear polarisation fraction. The HARPO (Hermetic ARgon POlarimeter) detector prototype that we built is a high pressure (0.5-4 bar) low pile-up and low-diffusion gas detector. We will present the results of its high-statistics characterisation in the 1.7-74 MeV fully-polarised and non-polarised gamma-ray beam provided by the BL01 line at NewSUBARU. The excellent value of the polarisation asymmetry dilution factor that we measured opens the possibility of having a polarimeter in space working in the MeV-GeV energy range. In conclusion, we will present the design of a balloon-flight prototype ST3G (Self-Triggered Time projection chamber as a Gamma-ray Telescope) which is being developed. We will discuss its expected performance.