Production of a square geometry americium standard source for use with photodiodes

• Autor(a) principal: COSTA, PRISCILA
• Data de Publicação: 2018
• Outros Autores: GERALDO, BIANCA, RAELE, MARCUS P., MARUMO, JULIO T., VICENTE, ROBERTO, ZAHN, GUILHERME S., GENEZINI, FREDERICO A., INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE
• Tipo de documento: Artigo de conferência
• Título da fonte: Repositório Institucional do IPEN
• Texto Completo: http://repositorio.ipen.br/handle/123456789/28272
• topic: americium 243; boron; calibration; electrodeposition; neutron detectors; photodiodes; brazilian cnen; silicon; square configuration; stainless steels; thermal neutrons; thin films

In the development of a thermal neutron detector using a square photodiode and a thin boron film, a radioactive calibration source with the same geometry was needed. An americium-243 standard source was produced by electrodeposition aiming at the calibration of a PIN-type silicon photodiode with a detection area of 10 x 10 mm2. To produce the samples two tests were performed. In the first test, a square stainless steel plate (10 x 10 mm2) was fixed on the surface of the conventional plate, which was removed after deposition. To reduce the loss of activity of the source, in the second test nail polish was applied on the silver plate leaving only an area of 10 x 10 mm2 without varnish coating. Once the electrodeposition process was completed, the activity concentration measurement was performed by alpha particle spectrometry. The first method presented a lower activity when compared to the total activity of Am-243 added initially. For the second method, the total activity was concetrated in the exposed square region (without nail polish).The results showed that it is possible to obtain a square geometry source; furthermore, the surrounding nail polish was not contaminated by 243Am. The comparison of these two approaches indicated that the second method was more efficient as it was possible to concentrate all the americium activity in the delimitated square area.