Hard-x-ray polarimetry with the Ramaty high energy solar spectroscopic imager (RHESSI)

Mark L. McConnell; David M. Smith; A. Gordon Emslie; Robert P. Lin; James M. Ryan

doi:10.1117/12.458879

14 February 2003 Hard x-ray polarimetry with the Ramaty High Energy Solar Spectroscopic Imager (RHESSI)

Mark L. McConnell, David M. Smith, A. Gordon Emslie, Robert P. Lin, James M. Ryan

Proceedings Volume 4843, Polarimetry in Astronomy; (2003) https://doi.org/10.1117/12.458879
Event: Astronomical Telescopes and Instrumentation, 2002, Waikoloa, Hawai'i, United States

Abstract

Although designed primarily as a hard X-ray imager and spectrometer, the Ramaty High Energy Solar Spectroscopic Imager (RHESSI) is also capable of measuring the polarization of hard X-rays (20-100 keV) from solar flares. This capability arises from the inclusion of a small unobstructed Be scattering element that is strategically located within the cryostat that houses the array of nine germanium detectors. The Ge detectors are segmented, with both a front and rear active volume. Low energy photons (below about 100 keV) can reach a rear segment of a Ge detector only indirectly, by scattering. Low energy photons from the Sun have a direct path to the Be and have a high probability of Compton scattering into a rear segment of a Ge detector. The azimuthal distribution of these scattered photons carries with it a signature of the linear polarization of the incident flux. Sensitivity estimates, based on simulations and in-flight background measurements, indicate that a 20-100 keV polarization sensitivity of less than a few percent can be achieved for X-class flares.

Citation Download Citation

Mark L. McConnell, David M. Smith, A. Gordon Emslie, Robert P. Lin, and James M. Ryan "Hard x-ray polarimetry with the Ramaty High Energy Solar Spectroscopic Imager (RHESSI)", Proc. SPIE 4843, Polarimetry in Astronomy, (14 February 2003); https://doi.org/10.1117/12.458879

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available