ASTM E 1855:2020

1.1 This test method covers the use of 2N2222A silicon bipolar transistors as dosimetry sensors in the determination of neutron energy spectra and as 1-MeV(Si) equivalent displacement damage fluence monitors. 1.2 The neutron displacement in silicon can serve as a neutron spectrum sensor in the range 0.1 to 2.0 MeV and can serve as a substitute when fission foils are not available. It has been applied in the fluence range between 2 x 10¹² n/cm ² to 1 x 10¹⁴ n/cm² and should be useful up to 1 x 10¹⁵ n/cm². This test method details the acquisition and use of 1-MeV(Si) equivalent fluence information for the partial determination of the neutron spectra by using 2N2222A transistors. 1.3 This sensor yields a direct measurement of the silicon 1-MeV equivalent fluence by the transfer technique. 1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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