The preparation and characterisation of 6LiF and 10B reference deposits for the measurement of the neutron lifetime
In beam experiments, the achievement of accurate neutron lifetime measurements heavily depends on the use of well characterised boron and/or lithium reference deposits to assess the neutron density. Sets of 6LiF and 10B reference deposits on silicon wafers were prepared by vacuum deposition using planetary rotating substrate holders. The uniformity of deposition was investigated using visible light spectrophotometry and accurate dimensional characterisation was carried out on the basis of travelling-microscope and talistep measurements. The results obtained agreed well with theoretical calculations based on the geometry of the evaporation system. The deposits prepared in successive evaporation runs were then characterised by neutron induced charged particle measurements calibrated by isotope dilution mass spectrometry. 6Li and 10B surface densities are certified with accuracies of 0.35-0.50% and 0.30-0.41%, respectively. An intercomparison of the 6Li and 10B calibrations confirms the consistency of the measurements.
Bibliographic Reference: Paper presented: 15th World Conference of the International Nuclear Target Dev. Society, Santa Fé (US), September 10-14, 1990
Availability: Available from (1) as Paper EN 35458 ORA
Record Number: 199011233 / Last updated on: 1994-12-01
Original language: en
Available languages: en