• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1
  • Tagged with
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Implementation and characterization of Silicon detectors for studies on neutron-induced nuclear reactions

Lehtilä, Leo January 2019 (has links)
Energy resolution characteristics of silicon surface barrier detector signals amplified by different preamplifiers and spectroscopic amplifiers have been studied. The characterization has been done using alpha particles from an 241Am source and spontaneous fission fragments from two Cf sources. The alpha and spontaneous fission activities of the sources have been measured and the isotopic compositions, ages, and initial activities of the two Cf sources have been calculated using the results from the activity measurements. 82.3% and 82.5% of the spontaneous fission activity of the two sources is found to originate from 252Cf. Heavy ion detection properties of two Si detector setups have been determined by measuring spontaneous fission fragments from one of the Cf sources in coincidence. The mass distribution of fission fragments is derived from the pulse spectra of the coincidence measurements. The conditions for future time resolution measurements have been established. Inquiries on commercially available ultra-thin Si detectors have been made. The purpose is to upgrade detector telescopes to lower the energy threshold of ΔE-ΔE-E identification of particles from neutroninduced nuclear reactions. Three manufacturers of Si detectors with thickness 20-25 µm and active area around 450 mm2 have been listed together with properties of the three offered detectors.

Page generated in 0.174 seconds