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Published July 1998 | public
Journal Article

The Cosmic-Ray Isotope Spectrometer for the Advanced Composition Explorer


The Cosmic-Ray Isotope Spectrometer is designed to cover the highest decade of the Advanced Composition Explorer's energy interval, from ∼50 to ∼500 MeV nucl^(−1), with isotopic resolution for elements from Z≃2 to Z≃30. The nuclei detected in this energy interval are predominantly cosmic rays originating in our Galaxy. This sample of galactic matter can be used to investigate the nucleosynthesis of the parent material, as well as fractionation, acceleration, and transport processes that these particles undergo in the Galaxy and in the interplanetary medium. Charge and mass identification with CRIS is based on multiple measurements of dE/dx and total energy in stacks of silicon detectors, and trajectory measurements in a scintillating optical fiber trajectory (SOFT) hodoscope. The instrument has a geometrical factor of ∼r250 cm^2 sr for isotope measurements, and should accumulate ∼5×10^6 stopping heavy nuclei (Z>2) in two years of data collection under solar minimum conditions.

Additional Information

© 1998 Kluwer Academic Publishers. This research was supported by the National Aeronautics and Space Administration at the Space Radiation Laboratory (SRL) of the California Institute of Technology (under contract NAS5–32626 and grant NAGW-1919), the Jet Propulsion Laboratory (JPL), the Goddard Space Flight Center (GSFC), and Washington University. We wish to thank the many individuals and organizations who made important contributions to the development of CRIS: J. H. Marshall III of Radcal Corp., J. Gill and B. Mitchell of Harris Corp., and R. McKenzie of Teledyne Corp. played major roles in the design, development, and fabrication of the custom VLSI chips and hybrid circuits, while G. Stupian and M. Leung of Aerospace Corp. provided their micro-focus x-ray facility for hybrid screening. J. Walton and his group at Lawrence Berkeley National Laboratory fabricated the silicon detectors. D. Aalami of Space Instruments was responsible for the design of the power supplies and also contributed to the design, fabrication, and testing of the other electronic assemblies. W. Blanchard of Falcon Services provided all of the board layouts except for the logic board, which was provided by J. Stelma of Design Solutions. Electronic assembly was carried out at Caltech and JPL by N. Neverida and T. Ngo-Luu of JPL with the help of T. Dea, who also assisted during conformal coating and environmental testing at JPL. V. Nguyen of Caltech was responsible for most of the subassembly testing. W. Morris of Caltech received and kitted parts and J. Valenzuela of Space Instruments assisted in PCB production and technical document control. B. Williams of JHU/APL was responsible for the thermal design and support. At Caltech, B. Sears, R. Selesnick, J. Cummings, and L. Sollitt provided calibration and analysis support, G. Allbritton was responsible for detector testing, G. Flemming contributed to the flight software, J. Burnham provided engineering support, F. Spalding was responsible for project administration, and D. Kubly and R. Kubly performed a variety of secretarial tasks. In addition, M. Calderon, A. Davis, and T. Garrard assisted with computing issues, R. Paniagua and R. Borup provided support in the Caltech Physics shop, and B. Wong helped with a variety of laboratory tasks. J. Lopez-Tiana and E. Friese provided purchasing and contract support. At JPL, B. Potter assisted in expediting the VLSI build at Harris Corp., D. Cipes- Cwik and R. Hill carried out the hybrid inspections at Teledyne, N. Silva contributed to the assembly of the telescope modules and instrument card cage, as well as development of specifications for magnetics parts, W. Powell served as instrument expeditor, K. Evans provided advice on parts, J. DePew provided technical support for calibrations and laboratory testing, and M. Salama and T. Scharton assisted with mechanical design issues along with P. Rentz of EER Systems Corporation. R. Pool consulted on contractual issues. AtWashington University, G. Simberger was responsible for parts procurement, electronics construction, and inspection. D. Braun was responsible for the organization and inspection of the mechanical parts, the fabrication of the fibers, and the assembly of the fiber planes. J. Cravens of Southwest Research performed the quality assurance on SOFT and provided inputs on the use of image intensifiers in space. H. Darlington of JHU/APL contributed to the design and development of the image intensified CCD cameras. S. Battel of Battel Engineering contributed to the high voltage power supply development. T. Soulanille of Altadena Instruments performed a design review for the camera electronics system. L. Geer, presently at the National Institute of Health, had the original idea to use a photodiode coupled to the image intensifiers for triggering. T. Hardt, D. Steelman, D. Huelsman, and A. Biondo fabricated substantial portions of the SOFT detector in the Washington University machine shop. D. Yates, J. Jarrell, and C. Kruger provided support with contracting, accounting, and proposal preparation. J. Howorth, D.Wilcox, and their staff at Photek developed the image intensifiers and provided helpful advice on the technical details of image intensifiers. G. M'Sadoques of K&M Electronics designed the image intensifier high-voltage power supplies, which were also fabricated by the same company. At GSFC, B. Fridovich provided administrative support, M.Madden and B. Nahory were responsible for detector testing, and S. Hendricks of Swales and Associates, Inc. assisted with mechanical design issues. Accelerator testing of the CRIS detectors was made possible by N. Anantaraman, R. Ronningen, and the staff of the National Superconducting Cyclotron Laboratory at Michigan State University, while H. Specht, D. Schardt, and the staff of the GSI heavy ion accelerator in Darmstadt, Germany made possible the heavy ion calibrations of the completed CRIS instrument. The spacecraft team at JHU/APL provided assistance in many areas while CRIS was being integrated and tested on the spacecraft. Finally, we thank A. Frandsen, G. Murphy, H. Eyerly, M. Breslof, C. Rangel, and M. McElveney of the ACE Payload Management Office for their untiring support and assistance, and D. Margolies, J. Laudadio, and the ACE Project Office at GSFC for their help in all phases of the CRIS development.

Additional details

August 19, 2023
October 25, 2023