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Van de Graaff based positron source production

<p> The anti-matter counterpart to the electron, the positron, can be used for a myriad of different scientific research projects to include materials research, energy storage, and deep space flight propulsion. Currently there is a demand for large numbers of positrons to aid in these mentioned research projects. There are different methods of producing and harvesting positrons but all require radioactive sources or large facilities. Positron beams produced by relatively small accelerators are attractive because they are easily shut down, and small accelerators are readily available. </p><p> A 4MV Van de Graaff accelerator was used to induce the nuclear reaction <sup> 12</sup>C(d,n)<sup>13</sup>N in order to produce an intense beam of positrons. 13N is an isotope of nitrogen that decays with a 10 minute half life into <sup>13</sup>C, a positron, and an electron neutrino. This radioactive gas is frozen onto a cryogenic freezer where it is then channeled to form an antimatter beam. The beam is then guided using axial magnetic fields into a superconducting magnet with a field strength up to 7 Tesla where it will be stored in a newly designed Micro-Penning-Malmberg trap. </p><p> Several source geometries have been experimented on and found that a maximum antimatter beam with a positron flux of greater than 0.55&times;10<sup> 6</sup> e+s<sup>-1</sup> was achieved. This beam was produced using a solid rare gas moderator composed of krypton. Due to geometric restrictions on this set up, only 0.1-1.0% of the antimatter was being frozen to the desired locations. Simulations and preliminary experiments suggest that a new geometry, currently under testing, will produce a beam of 107 e+s<sup>-1</sup> or more.</p>

Identiferoai:union.ndltd.org:PROQUEST/oai:pqdtoai.proquest.com:3732705
Date04 November 2015
CreatorsLund, Kasey Roy
PublisherWashington State University
Source SetsProQuest.com
LanguageEnglish
Detected LanguageEnglish
Typethesis

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