NTRS - NASA Technical Reports Server

Back to Results
silicon detector system for cross section measurementsIn order to estimate the radiation shielding effectiveness of materials it is necessary to know cosmic ray particles are broken up as they pass though these materials. The breakup of cosmic ray particles is characterized by the nuclear fragmentation cross sections, i.e. an effective geometrical cross section assigned to each target nucleus that represents its apparent size for fragmenting the incident particle. The values of these cross sections depend on the details of nuclear physics and cannot be calculated from first principles owing to the many-body nature of the interactions. The only way to determine them is to measure them. Once a sufficient number of cross sections have been measured, the systematic nature of the interactions allows other cross-sections to be estimated. The number of cross sections that contribute to the estimation of shielding effectiveness is very large 10,000. Fortunately most make minor contributions. These can be estimated from nuclear systematics. Only those who's uncertainties make significant contributions to the error in the shielding effectiveness estimations need to be measured. In the past it has proven difficult to measure light fragment production cross sections from the interactions of heavy cosmic rays owing to the size of the detectors used. We have developed a highly pixilated silicon (Si) detector system that can individually identify these light fragments while making efficient use of costly accelerator time. This system is an outgrowth of detector technology developed under a CDDF and a Code S sponsored cosmic ray experiment.
Document ID
Document Type
Date Acquired
August 21, 2013
Publication Date
December 1, 2003
Publication Information
Publication: Biological and Physical Space Research Laboratory 2002 Science Review
Subject Category
Instrumentation and Photography
Distribution Limits
Work of the US Gov. Public Use Permitted.

Related Records

IDRelationTitle20040073490Analytic PrimaryBiological and Physical Space Research Laboratory 2002 Science Review