On July 12 in 2013 the PoGOLite balloon-borne telescope was launched from Esrange and flow to Norilsk in Russia in a circumpolar flight over Canada studying the polarisation of gamma-rays from pulsars. Due to the specific conditions during the Arctic summer with continuous daylight and nearly constant solar heating kept the balloon at a constant altitude with a minimum of ballast. The balloon was taken down after 12 days.
A new flight is planned in the summer of 2016, this time from Esrange to Canada. The light-weight Polarized Gamma-ray Observer (PoGOLite) experiment is designed to measure the polarization of soft gamma rays in the 25 keV – 80 keV energy range.
PI is Mark Pearce from KTH, Sweden.
A balloon of type Raven SF-39.57 will be used.
The scientific gondola has a mass of approximately 1900 kg.
The PoGo+ project is a collaborative project between Swedish and Japanese scientific teams.
The flight is based on a re-flight of a modified design and hardware that flow 2013 with the same mechanical and electrical interfaces. SSC has built the gondola structure of the payload with solar panels and is also responsible for the power, housekeeping and communication systems. SSC is also responsible for the complete balloon flight system, launch from Esrange Space Center, flight to Canada and for recovery.
Description of the instrument and the mission
Polarized gamma rays are expected from a wide variety of sources including rotation-powered pulsars, accreting black holes and neutron stars, and jet-dominated active galaxies. Polarization has never been measured at soft gamma-ray energies where non-thermal processes are likely to produce high degrees of polarization.
The polarization is derived from the azimuthal distribution of Compton scattering angles in the sensitive volume of the instrument.
The scattering angle will be measured by detecting coincident Compton scattering and photo-absorption sites in an array of 217 phoswich detectors.
Polarization measurement requires high purity coincident signal detection. PoGOLite applies a well-type Phoswich Detector technology for this purpose. The technology has proven to be very effective in reducing source-confusion and cosmic-ray-induced backgrounds.
The PoGOLite experiment is developed by groups in Japan and Sweden.
Mark Pearce from KTH (The Royal Institute of Technology) is the spokesman for the international PoGOLite Collaboration and is leading the Swedish Consortium.
|Launch site||Esrange Space Center|
|Launch date||July 12, 2016|
|Balloon size||1,2 Mm³|
Mr. Christian Lockowandt, Project manager SSC