Astronomical Instrumentation for Project Polariscope.

Abstract

view Abstract Citations References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Astronomical Instrumentation for Project Polariscope. Teska, T. M. ; Pellicori, S. F. ; Roland, E. H. Abstract A 28-inch balloon-borne telescope with a Wollaston prism polarimeter is to be flown during the winter of 1963-64 in order to make observations in the ultraviolet between 3000 and 2000 A (Gehrels and Teska, AppI. opt. 2, 67,1963). The Wollaston-type prism is constructed of ammonium dihydrogen phosphate (ADP). The prism tises a 250 angle of cut with the halves of the prism contacted with a silicone fluid. Since the birefringent material used for construction is fragile, the prism is sealed in an insulated cell having high thermal mass. This cell is provided with fused silica windows. The transmission of each of the optical beams slowly drops from 70% at 3000 A to 30% at 1950 A for the 40-mm length of prism used. Tentative filters having widths of about 200 A have been constructed and tested. The filters are dyed silicone fluids mounted between silica windows and cast in an epoxy cell. The filter materials used are p-dimethylaminobenzaldehyde and 2-methyl- pyrazine. The filters are transparent above 3500 A and must be used with "solar-blind" photocathodes such as cesium telluride. The photomultiplier outputs are integrated using transistorized versions of the Weitbrecht Mark-Six system. A single-ended electrometer-tube input stage is followed by a silicon field-effect transistor which drives the output stages of the amplifier. The amplifier is temperature compensated for low zero drift consistent with a readout resolution of one part in 4000. Dry-reed relays are used for capacitor switching. For testing of components in the laboratory, a number of optical modules can be bolted together in various serial arrangements. The individual modules are a monochromator, a collimator, a reference detector, a goniometer table, ai~ ADP Glan- Thompson polarizing prism, a telescope, and a detector. This test instrument is rigidly constructed to allow it to be mounted on the Polariscope telescope for polarimeter calibration. Publication: The Astronomical Journal Pub Date: 1963 DOI: 10.1086/109054 Bibcode: 1963AJ.....68Q.295T full text sources ADS |