urn:nasa:pds:context:instrument:xrs.near 1.1 1.14.0.0 Product_Context 2023-05-12 1.1 Removed extraneous external references, replaced description with a short summary, and added NAIF instrument ID and Type List Area 2016-10-01 1.0 extracted metadata from PDS3 catalog and modified to comply with PDS4 Information Model urn:nasa:pds:context:instrument_host:spacecraft.near instrument_to_instrument_host Goldsten, J.O., The NEAR X-Ray/Gamma-Ray Spectrometer, Johns Hopkins APL Technical Digest, Vol. 19, pp. 126-135, 1998. reference.GOLDSTEN1998 Goldsten, J.O., R.L. McNutt, R.E. Gold, S.A. Gary, E. Fiore, S.E. Schneider, J.R. Hayes, J.I. Trombka, S.R. Floyd, W.V. Boynton, S. Bailey, J. Bruckner, S.W. Squyres, L.G. Evans, P.E. Clark, and R. Starr, The X-Ray/Gamma-Ray Spectrometer on the Near Earth Asteroid Rendezvous Mission, Space Sciences Review, Vol. 82, pp. 169-216, 1997. reference.GOLDSTENETAL1997 Starr, R., P.E. Clark, L.G. Evans, S.R. Floyd, T.P. McClanahan, J.I. Trombka, J.O. Goldsten, R.H. Maurer, R.L. McNutt, Jr., and D.R. Roth, Radiation effects in the Si-PIN detector on the Near Earth Asteroid Rendezvous Mission, Nuclear Instruments and Methods in Physics Research Section A, Vol. 428, pp. 209-215, 1999. reference.STARRETAL1999 Trombka, J., S. Floyd, W. Boynton, S. Bailey, J. Bruckner, S. Squyres, L. Evans, P. Clear, R. Starr, E. Fiore, R. Gold, J. Goldsten, and R. McNutt, Compositional Mapping With The Near X-ray/Gamma-ray Spectrometer, J. Geophys. Res., Vol. 102, pp. 23729-23750, 1997. reference.TROMBKAETAL1997 XRAY SPECTROMETER Spectrometer -93003 The NEAR XRS is part of the X-Ray/Gamma-Ray Spectrometer (XGRS) suite on the NEAR mission. It is an X-ray resonance fluorescence spectrometer that detects the characteristic X-ray line emissions excited by solar X-rays from major elements in the asteroid's surface. It covers X-rays in the energy range from 1 to 10 keV using three gas proportional counters. The balanced, differential filter technique is used to separate the closely spaced Mg, Al, and Si lines lying below 2 keV. The gas proportional counters directly resolve higher energy line emissions from Ca and Fe. A mechanical collimator gives the XRS a 5 deg FOV, with which it will map the chemical composition of the asteroid at spatial resolutions as great as 2 km in the low orbits. It also includes a separate solar monitor system to measure continuously the incident spectrum of solar X-rays, using both a gas proportional counter and a high-spectral-resolution silicon X-ray detector. The XRS performs in-flight calibration using a calibration rod with Fe-55 sources that can be rotated into or out of the detector FOV.