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Full-Text Articles in Physical Sciences and Mathematics
Development Of A Hard X-Ray Polarimeter For Astrophysics, Mark L. Mcconnell, John R. Macri, M Mcclish, James M. Ryan, D J. Forrest, W T. Vestrand
Development Of A Hard X-Ray Polarimeter For Astrophysics, Mark L. Mcconnell, John R. Macri, M Mcclish, James M. Ryan, D J. Forrest, W T. Vestrand
Space Science Center
We have been developing a Compton scatter polarimeter for measuring the linear polarization of hard X-rays (100-300 keV) from astrophysical sources. A laboratory prototype polarimeter has been used to successfully demonstrate the reliability of our Monte Carlo simulation code and to demonstrate our ability to generate a polarized photon source in the lab. Our design concept places a self-containedpolarimeter module on the front-end of a a 5-inch position sensitive PMT (PSPMT). We are currently working on the fabrication of a science model based on this PSPMT concept. Although the emphasis of our development effort is towards measuring hard X-rays from …
Mev Measurements Of Gamma-Ray Bursts By Cgro-Comptel, A Connors, W Collmar, W Hermsen, S C. Kappadath, R M. Kippen, L Kuiper, Mark L. Mcconnell, F Pelaez, James M. Ryan, V Schonfelder, M Varendorff, O R. Williams, C Winkler, C A. Young
Mev Measurements Of Gamma-Ray Bursts By Cgro-Comptel, A Connors, W Collmar, W Hermsen, S C. Kappadath, R M. Kippen, L Kuiper, Mark L. Mcconnell, F Pelaez, James M. Ryan, V Schonfelder, M Varendorff, O R. Williams, C Winkler, C A. Young
Space Science Center
Since the launch of the Compton Gamma-Ray Observatory in April 1991, the imaging COMPTEL telescope has accumulated positions and 0.75–30 MeV spectra of more than thirty gamma-ray bursts within its ∼π sr field of view. In an ongoing collaboration with BACODINE/GCN, COMPTEL positions are relayed to a global network of multiwavelength observers in near real time (∼10 minutes). Here we summarize the MeV properties, and present spatial, spectral, and temporal data for the latest of these events, GRB 970807. In concurrence with earlier SMM and current BATSE, OSSE, and EGRET measurements, COMPTEL data add to the accumulating evidence that GRB …
Sontrac—A Low Background, Large Area Solar Neutron Spectrometer, James M. Ryan, D Holslin, John R. Macri, Mark L. Mcconnell, Cornelia B. Wunderer
Sontrac—A Low Background, Large Area Solar Neutron Spectrometer, James M. Ryan, D Holslin, John R. Macri, Mark L. Mcconnell, Cornelia B. Wunderer
Space Science Center
SONTRAC is a scintillating fiber neutron detector designed to measure solar flare neutrons from a balloon or spacecraft platform. The instrument is comprised of alternating orthogonal planes of scintillator fibers viewed by photomultiplier tubes and image intensifier/CCD camera optics. It operates by tracking the paths of recoil protons from the double scatter of 20 to 200 MeV neutrons off hydrogen in the plastic scintillator, thereby providing the necessary information to determine the incident neutron direction and energy. SONTRAC is also capable of detecting and measuring high-energy gamma rays >20 MeV as a “solid-state spark chamber.” The self-triggering and track imaging …
A Hard X-Ray Solar Flare Polarimeter Design Based On Scintillating Fibers, James M. Ryan, Mark L. Mcconnell, D J. Forrest, John R. Macri, M Mcclish, W T. Vestrand
A Hard X-Ray Solar Flare Polarimeter Design Based On Scintillating Fibers, James M. Ryan, Mark L. Mcconnell, D J. Forrest, John R. Macri, M Mcclish, W T. Vestrand
Space Science Center
We have developed a design for a Compton scatter polarimeter to measure the polarization of hard X-rays (50–300 keV) from solar flares. The modular design is based on an annular array of scintillating fibers coupled to a 5-inch position-sensitive PMT. Incident photons scatter from the fiber array into a small array of NaI detectors located at the center of the annulus. The location of the interactions in both the fiber array and in the NaI array can be used to measure the linear polarization of the incident flux. This compact design may be well-suited to a variety of astrophysical applications. …