OMPI Seminar: Chris Dydula and Dave Rogers and tour of Health Canada, Radiation Protection facilites

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Date: 
Thursday, December 15, 2016

Times: 2:00 - 3:00 - Tour of Health Canada facilites, 3:30 - 5:00 pm -  Refreshments start at 3:15 pm.

Location: Room RPB 205 (boardroom), Health Canada, 775 Brookfield Road, Ottawa. Please check in at the front desk.

The tour of Health Canada facilities requires sign up. Please RSVP Lindsay Beaton (lindsay [dot] beatonathc-sc [dot] gc [dot] ca).

Presentations:

1) "Prototyping an x-ray scatter projection imaging system at the Canadian Light Source"
By Chris Dydula, PhD student, Carleton University
Supervisor: Dr. Paul Johns

Abstract: A major challenge in traditional x-ray projection imaging, which utilizes only information from primary photons, is obtaining adequate soft-tissue contrast. We are developing a high soft-tissue contrast x-ray projection imaging technique at the Canadian Light Source synchrotron based on the detection of low-angle scattered photons. In order to acquire scatter images in reasonable times, we have configured a system with multiplexed 3 mm2 rectangular pencil beams at 33.2 keV and with samples moving continuously at 1 cm/s during the scan. A consequence of faster acquisition is an increase in the complexity of the scatter data, requiring additional corrections when reconstructing images.

 
2) "Using Monte Carlo to improve reference dosimetry for low dose rate brachytherapy"
By Dave W. O. Rogers, PhD, Carleton University

Abstract: TLD dosimetry with LiF has been widely used to establish dosimetry parameters for use in brachytherapy, most notably dose rate constants. However almost all of the literature is based on calibrations and factors from the 1980s and/or ignores the fact that the signal per unit dose to the LiF varies substantially with photon energy and/or ignores the fact that the dose to LiF per unit dose to water depends on the details of the seed and shape of the detector. This talk is about using Monte Carlo techniques to overcome these problems and to provide a reanalysis of measured dose rate constants for 24 different seeds. This improves the agreement between the calculated and measured values to within about 1% on average as opposed to the previous disagreement of 5% on average.