Change search
ReferencesLink to record
Permanent link

Direct link
PoGOLite: The Polarised Gamma-ray Observer
KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
2008 (English)Licentiate thesis, monograph (Other scientific)
Abstract [en]

PoGOLite is a balloon-borne experiment which will study polarised soft gamma-ray emission from astrophysical targets in the 25 keV – 80 keV energy range by applying well-type phoswich detector technology. Polarised 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. Polarisation measurements provide a powerful probe of the gamma-ray emission mechanism and the distribution of magnetic and radiation fields around the source. The polarisation is determined using Compton scattering and photoelectric absorption in an array of 217 plastic scintillators. The sensitive detector is surrounded by a segmented Bismuth Germanium Oxide (BGO) anticoincidence shield. The function of this shield is to reduce backgrounds from charged cosmic rays, primary and atmospheric gamma-rays, and atmospheric and instrumental neutrons. The anticoincidence shield consists of 427 BGO crystals with three different geometries. The characteristics of the BGO crystals of the bottom anticoincidence shield have been studied with particular focus on the light yield.

The PoGOLite polarimeter has a field of view of 2.4° x 2.4° and must be kept aligned to objects of interest on the sky. A star tracker forms part of the attitude control system. The star tracker system comprises a CCD camera, lens, and a baffle system. Preliminary studies have been made concerning optimization of the focus, flat field correction, map of hot pixel and CCD response. An estimate of the star magnitude limit is also derived and found to be compatible with the environment around the Crab, which is the first observational target. These studies pave the way toward an autonomous star tracking device which together with the other attitude control devices will reconstruct the pointing solution.

Place, publisher, year, edition, pages
Stockholm: KTH , 2008. , vi, 85 p.
Trita-FYS, ISSN 0280-316X ; 2008:10
National Category
Physical Sciences
URN: urn:nbn:se:kth:diva-4678ISBN: 978-91-7178-905-1OAI: diva2:13375
2008-04-04, Sal FA32, AlbaNova univ centrum, Roslagstullsbacken 21, Stockholm, 13:00
QC 20101118Available from: 2008-03-26 Created: 2008-03-26 Last updated: 2010-11-18Bibliographically approved

Open Access in DiVA

fulltext(6138 kB)264 downloads
File information
File name FULLTEXT01.pdfFile size 6138 kBChecksum SHA-1
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Marini Bettolo, Cecilia
By organisation
Particle and Astroparticle Physics
Physical Sciences

Search outside of DiVA

GoogleGoogle Scholar
Total: 264 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 285 hits
ReferencesLink to record
Permanent link

Direct link