{"id":945,"date":"2018-07-18T14:27:24","date_gmt":"2018-07-18T20:27:24","guid":{"rendered":"https:\/\/www.crpa-acrp-bulletin.ca\/?p=945"},"modified":"2021-05-08T22:41:37","modified_gmt":"2021-05-09T04:41:37","slug":"anthony-j-mackay-student-paper-contest-winner-le-gagnant-du-concours-de-communications-etudiantes-anthony-j-mackay","status":"publish","type":"post","link":"https:\/\/www.crpa-acrp-bulletin.ca\/fr\/2018\/07\/18\/anthony-j-mackay-student-paper-contest-winner-le-gagnant-du-concours-de-communications-etudiantes-anthony-j-mackay\/","title":{"rendered":"Anthony J. MacKay Student Paper Contest Winner \/ Le gagnant du concours de communications \u00e9tudiantes Anthony J. Mackay"},"content":{"rendered":"

Each year the Students and Young Professionals Committee organizes a student paper contest in conjunction with the CRPA annual conference. For more information, visit the CRPA website (http:\/\/crpa-acrp.org\/home\/?page_id=5295<\/a>).<\/em><\/p>\n

For 2018, instead of selecting one winner in advance of the conference, three finalists were selected to present their work at the conference. Each of the three finalists had their conference registration, travel, and accommodations provided courtesy of this year\u2019s student contest sponsor, the University of Ontario Institute of Technology (UOIT).<\/em><\/p>\n

The winner of this year\u2019s Anthony J. MacKay Award is Humza Nusrat, a fourth-year PhD student at Ryerson University.<\/em><\/p>\n

\"\"<\/p>\n

\n

R\u00e9sum\u00e9<\/h4>\n

La connaissance quant \u00e0 la dose absorb\u00e9e d\u2019un rayonnement, en plus de sa qualit\u00e9<\/em>, c\u2019est-\u00e0-dire de la capacit\u00e9 du rayonnement \u00e0 endommager les tissus vivants, peut \u00eatre tr\u00e8s utile. En effet, en mesurant le spectre d\u2019\u00e9nergie, il est possible de conna\u00eetre plusieurs caract\u00e9ristiques de la source du rayonnement. R\u00e9ciproquement, il est aussi possible de d\u00e9terminer l\u2019efficacit\u00e9 biologique relative maximale du spectre d\u2019\u00e9nergie. Cet article pr\u00e9sente une nouvelle technique pour conna\u00eetre le spectre d\u2019\u00e9nergie \u00e0 l\u2019aide de scintillateurs plastiques dop\u00e9s. En effet, en ajoutant \u00e0 des scintillateurs des niveaux vari\u00e9s d\u2019\u00e9l\u00e9ments \u00e9lev\u00e9s en Z, le spectre d\u2019\u00e9nergie, et subs\u00e9quemment le transfert \u00e9nerg\u00e9tique lin\u00e9aire ainsi que l\u2019efficacit\u00e9 biologique relative, peuvent \u00eatre connus au moyen d\u2019une matrice de simulations de mod\u00e8les et de l\u2019appareillage de d\u00e9tection utilis\u00e9s dans cette \u00e9tude.<\/p>\n<\/div><\/div><\/div>\n

A novel method for resolving the energy spectrum of a radiation beam\u00a0using doped plastic scintillators<\/h2>\n

By Humza Nusrat
\n<\/strong>Department of Physics, Ryerson University<\/p>\n

Coauthors
\nGeordi Pang & Arman Sarfehnia
\nOdette Cancer Centre, Sunnybrook Health Sciences Centre
\nToronto, ON<\/p>\n

Introduction<\/h3>\n

Knowledge regarding the quality<\/em> of radiation, the ability of radiation to cause damage to living tissue, in addition to absorbed dose can be very useful. The potential biological damage caused by low-energy X-rays or heavy charged particles can be many times more severe than the 1 MeV (or higher) photons typically used in cancer radiotherapy.<\/p>\n

In cancer radiotherapy, absorbed dose is used to optimize the amount of radiation delivered to the patient, but does not account for variations in radiation quality (energy levels). Numerous studies have shown that the impact of low-energy scattered radiation on the radiation damage to the patient must be measured for optimal treatment. According to current literature, these low-energy particles may be causing more damage to tissue (by inducing cell death) than previously predicted.<\/p>\n

In the radiation protection industry, a radiation-weighting factor (WR<\/sub>) is used to account for variations in radiation quality. However, these factors are often gross estimations.<\/p>\n

By measuring the energy spectrum, many characteristics of the radiation source\/beam can be resolved. Using the National Institute of Standards and Technology (NIST) collisional stopping-power database, the linear energy transfer spectrum can be obtained if the energy spectrum is known. Similarly, the maximum relative biological effectiveness can be determined from the energy spectrum, as shown by Nusrat et al. (2018)<\/a>.<\/p>\n

This paper presents a novel technique for resolving the energy spectrum using doped plastic scintillators.<\/p>\n

Methods<\/h3>\n

Plastic scintillators are made of organic materials that emit visible light upon interacting with radiation. Their response is intrinsically dependent on the stopping power of incoming radiation, as shown through Birks\u2019 Law (Birks, 1964).<\/p>\n

Using organometallic chemistry, various amounts of high-Z dopants can be incorporated into the scintillator volume. By adding high-Z elements, the radiation interaction cross-sections of the scintillator can be tuned in order to change its sensitivity to certain energy ranges (e.g., adding high-Z dopants can induce greater sensitivity to low-energy X-rays).<\/p>\n

Four different scintillators were used: 0.0%, 1.0%, 1.5%, and 5.0% Pb\u2013doped plastic scintillators (Eljen Technology, Sweetwater, TX). In order to resolve the energy spectrum, two main challenges needed to be overcome:<\/p>\n