NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Iridium and tantalum foils for spaceflight neutron dosimetry.Description of a two-foil system of iridium and tantalum which can measure thermal and intermediate energy neutrons at flux densities of 1 neutron/sq cm-sec over a ten-day lunar mission (1,000,000 neutrons/sq cm). The foils are chemically inert and nontoxic, weigh less than 1 g each, and require only routine gamma pulse height analysis for activation measurement. Detection of fluences below 1,000,000 neutrons/sq cm are achieved for counts of foil activity made as late as two months following neutron exposure. Tantalum foils flown in Apollo 11 indicated a mean dose equivalent to the astronauts of less than 16 mrem from thermal plus intermediate energy neutrons, while nuclear emulsion track analysis indicated approximately 17 mrem from neutrons of energy greater than 0.6 MeV. Iridium foils flown on Apollo 12 indicated dose equivalents of 1.8 to 2.8 mrem from thermal neutrons, excluding tissue thermalized SNAP-27 neutrons.
Document ID
19720052235
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
English, R. A.
(Kelsey-Seybold Clinic; NASA, Manned Spacecraft Center Houston, Tex., United States)
Liles, E. D.
(Boeing Co., Space Div.; NASA, Manned Spacecraft Center Houston, Tex., United States)
Date Acquired
August 6, 2013
Publication Date
May 1, 1972
Publication Information
Publication: Health Physics
Volume: 22
Subject Category
Instrumentation And Photography
Accession Number
72A35901
Funding Number(s)
CONTRACT_GRANT: NAS9-10364
CONTRACT_GRANT: NAS9-9965
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available