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Title: A new method of observing weak extended x-ray sources with the Reuven Ramaty High-Energy Solar Spectroscopic Imager

Abstract

We present a new method, fan-beam modulation, for observing weak extended x-ray sources with the Reuven Ramaty High-Energy Solar Spectroscopic Imager (RHESSI). This space-based solar x-ray and {gamma}-ray telescope has much greater sensitivity than previous experiments in the 3-25 keV range, but is normally not well suited to detecting extended sources since their signal is not modulated by RHESSI's rotating grids. When the spacecraft is offpointed from the target source, however, the fan-beam modulation time-modulates the transmission by shadowing resulting from exploiting the finite thickness of the grids. In this article we detail how the technique is implemented and verify its consistency with sources with clear known signals that have occurred during RHESSI offpointing: microflares and the Crab Nebula. In both cases the results are consistent with previous and complementary measurements. Preliminary work indicates that this new technique allows RHESSI to observe the integrated hard x-ray spectrum of weak extended sources on the quiet Sun.

Authors:
; ; ;  [1]
  1. Space Sciences Laboratory, University of California at Berkeley, Berkeley, California 94720-7450 (United States)
Publication Date:
OSTI Identifier:
20953262
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 78; Journal Issue: 2; Other Information: DOI: 10.1063/1.2437120; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; CRAB NEBULA; EQUIPMENT; GAMMA RADIATION; GRIDS; HARD X RADIATION; KEV RANGE; MODULATION; SENSITIVITY; SIGNALS; SOLAR FLARES; SPACE; SPECTRA; SUN; TELESCOPES; X-RAY SOURCES

Citation Formats

Hannah, Iain G., Hurford, Gordon J., Hudson, Hugh S., and Lin, Robert P.. A new method of observing weak extended x-ray sources with the Reuven Ramaty High-Energy Solar Spectroscopic Imager. United States: N. p., 2007. Web. doi:10.1063/1.2437120.
Hannah, Iain G., Hurford, Gordon J., Hudson, Hugh S., & Lin, Robert P.. A new method of observing weak extended x-ray sources with the Reuven Ramaty High-Energy Solar Spectroscopic Imager. United States. doi:10.1063/1.2437120.
Hannah, Iain G., Hurford, Gordon J., Hudson, Hugh S., and Lin, Robert P.. Thu . "A new method of observing weak extended x-ray sources with the Reuven Ramaty High-Energy Solar Spectroscopic Imager". United States. doi:10.1063/1.2437120.
@article{osti_20953262,
title = {A new method of observing weak extended x-ray sources with the Reuven Ramaty High-Energy Solar Spectroscopic Imager},
author = {Hannah, Iain G. and Hurford, Gordon J. and Hudson, Hugh S. and Lin, Robert P.},
abstractNote = {We present a new method, fan-beam modulation, for observing weak extended x-ray sources with the Reuven Ramaty High-Energy Solar Spectroscopic Imager (RHESSI). This space-based solar x-ray and {gamma}-ray telescope has much greater sensitivity than previous experiments in the 3-25 keV range, but is normally not well suited to detecting extended sources since their signal is not modulated by RHESSI's rotating grids. When the spacecraft is offpointed from the target source, however, the fan-beam modulation time-modulates the transmission by shadowing resulting from exploiting the finite thickness of the grids. In this article we detail how the technique is implemented and verify its consistency with sources with clear known signals that have occurred during RHESSI offpointing: microflares and the Crab Nebula. In both cases the results are consistent with previous and complementary measurements. Preliminary work indicates that this new technique allows RHESSI to observe the integrated hard x-ray spectrum of weak extended sources on the quiet Sun.},
doi = {10.1063/1.2437120},
journal = {Review of Scientific Instruments},
number = 2,
volume = 78,
place = {United States},
year = {Thu Feb 15 00:00:00 EST 2007},
month = {Thu Feb 15 00:00:00 EST 2007}
}