Speaker
Dr
Merlin Kole
(University of Geneva)
Description
Polarimetry is a powerful tool to study the emission processes involved in high energy astrophysical events such as Gamma-Ray Bursts (GRBs). Despite the wealth of information which can be extracted from polarimetry measurements few have been performed successfully thus far. POLAR is a novel space-borne Compton polarimeter foreseen to be launched in 2016 on the Chinese spacelab TG-2. The instrument is designed for dedicated measurements of the hard X-ray polarisation of the prompt emission of GRBs in the energy range 50−500 keV. The polarisation degree and angle of a photon flux can be extracted by measuring the Compton scattering angles when the photons interact in a detector. The Compton scattering angles of the incoming photons are measured in POLAR using a finely segmented plastic scintillator array consisting of 1600 bars. The bars have a surface area of 6 by 6 mm and a length of 176 mm and are read out in groups of 64 by 25 flat-panel multi-anode photomultipliers. Due to its large granularity POLAR can measure the photon interaction locations, and therefore the scattering angles, with a high precision resulting in a relatively high modulation factor. The instrument furthermore has a relatively large effective area and a field of view of 1/3 of the sky thereby optimising it for studying GRBs. The instrument was shown through Geant4 simulations to be capable of performing measurements with a minimum detectable polarization below 10% for several GRBs per year. The flight model has recently been constructed and was tested extensively in recent months. The results from the instrument calibration measurements, performed using both radioactive sources and synchrotron facilities, and the results from the flight qualification tests will be presented along with the future prospects.
| Registration number following "ICRC2015-I/" | 353 |
|---|---|
| Collaboration | -- not specified -- |
Primary author
Dr
Merlin Kole
(University of Geneva)
Co-authors
Aleksandra RUTCZYNSKA
(National Centre for Nuclear Research)
Ania Zwolinska
(National Centre for Nuclear Research)
B.B. Wu
(Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences)
Catherine LECHANOINE-LELUC
(University of Geneva)
Divic Rapin
(Universite de Geneve (CH))
Dominik Rybka
(PSI)
H.H. Xu
(Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences)
H.L. Shi
(Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences)
H.L. Xiao
(Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences)
Ignacio Cernuda
(University of Geneva/ISDC)
Mr
Ilia Britvitch
(ETH, Zurich)
J.C. Sun
(Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences)
J.T. Liu
(Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences)
J.Y. Ch
(Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences)
Jacek Szabelski
(National Centre for Nuclear Research, Poland)
L.Y. Zhang
(Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences)
Li Zhang
(Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences)
Lu Li
(ey Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences)
M.N. Kong
(ey Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences)
Prof.
Martin Pohl
(Universite de Geneve (CH))
Neal Gauvin
(U)
Dr
Nicolas Produit
(ISDC/unige)
R.J. Wang
(Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences)
Radoslaw MARCINKOWSKI
(PSI)
S.N. Zhang
(Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences)
Silvio Orsi
(Universite de Geneve (CH))
T.W. Bao
(Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences)
Tadeusz Batsch
(National Centre for Nuclear Research)
Tancredi Bernasconi
(Universite de Geneve (CH))
Wojtek Hajdas
(Paul Scherrer Institut)
X. Liu
(Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences)
X. Wen
(Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences)
Y.J. Zhang
(Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences)
Y.W. Dong
(Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences)
