Thesis (M.S.)--University of Texas at El Paso, 2008. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.

In the European XFEL, electrons bunches are accelerated up to 20 GeV and thenenter undulators where coherent X-rays are produced which can be used for imaging atva molecular level. Electrons may stray from the path and hit the permanent magnets inthe undulators. It is well known that ionizing radiation can affect the magnetic characteristics of permanent magnets. The undulators are therefore equipped with a type of semiconductor dosimeters, RADFETs, so that the potential damage from ionizing radiation to the magnets can be measured and corrected for. It is also known that heat will be generated from air-coils in the accelerator which can change the ambient temperature around the dosimeters up to 25 K. All semiconductor technology is highly susceptible totemperature. This report investigates the fading characteristics of the RADFET under different temperatures and times after irradiation. It also investigates the dose responseunder dierent temperatures and estimates the magnitude of errors in measured dose which can be expected if temperatures are not accounted for. It is seen that a delta T of a few K can have a large impact on RADFETs' ability to both record and retain dose. A strong time dependence is also seen. The fading is the largest during irradiation andthen slows down exponentially, stabilizing after 1 to 2 months. An increase from 20 deg C to 26 deg C will increase the fading by 2 Gy/h during irradiation, and 0.015 Gy/h weeks afterirradiation. It is estimated that dose measurements at XFEL can have errors of up to 14% if long-term fading is not accounted for. A model for estimating long-term fading as a function of temperature is proposed.

The study aimed to investigate how continuing professional development (CPD) activities, through the development of a CPD educational framework, can assist Medical Radiation Science (MRS) practitioners to engage in reflective practice while entrenched in a protocol driven workplace culture. The study, with action research as the chosen methodology, and used both quantitative and qualitative methodology, was divided into two phases. The first phase of data collection aimed to inform the researcher of the needs of the MRS profession. The second phase of the study involved the design and development of an educational framework for CPD, based on current theories of learning and teaching using the framework and data collected from the first phase of the study, an online module was developed. The objectives of the module were to increase participants' knowledge in breast planning in radiation therapy by assisting participants to engage in reflective practice. The cyclical process of action research was used to pilot the module twice with two groups of volunteer radiation therapists. The online module was evaluated using Kirkpatrick's four level evaluation model (Kirkpatrick, 1998; Guskey, 2000). Based on Boud et al.'s reflection model (1985), all participants showed evidence of action, affective and perspective outcomes. They also demonstrated successful development of lifelong learning attributes, were empowered and their learning had a positive impact in their workplace. They began to assume a more proactive role and increased clinical responsibilities, engaging colleagues in collaborative reflections and adopting evidence-based approaches in advancing workplace practices. The study shows that it is possible to assist MRS practitioners to engage in reflective practice within a CPD educational framework online. The study also shows the importance of reflective practice, lifelong learning and transformative learning in CPD. Reflective practice liberates and empowers participants, lifelong learning equips them to continue learning and transformative learning facilitates perspective transformation. Thus, an effective educational framework is one that adopts a holistic approach towards CPD, by incorporating reflective practice, lifelong learning and transformative learning. The educational framework adopted in the present study may be extrapolated to CPD programs in other MRS disciplines and other healthcare professions.

Thesis (Ph.D.)--University of Wollongong, 2006. / Typescript. Includes bibliographical references: p. 161-174.

Literature has shown the importance of lifelong learning in the training of today's workforce and the crucial role of Higher Education in preparing graduates for lifelong learning. The aim of the current study is to establish the profile of Medical Radiation Science (MRS) practitioners as lifelong learners and to examine the implications of these findings for MRS undergraduate programs in Australia. The study builds on Candy et. al.'s 1994 report, Developing Lifelong Learners through Undergraduate Education, by drawing on the report's profile of lifelong learners and the features of the undergraduate program that promote lifelong learning. This present study used both quantitative and qualitative approaches, including collating the stakeholders' views on lifelong learning via surveys, one-to-one interviews and focus group discussion.Findings from this study indicate that all stakeholders (MRS practitioners, Heads of MRS Departments, students and teaching staff) viewed lifelong learning to be relevant to the profession and are important attributes for MRS practitioners to attain. However, attributes that were directly related to clinical competencies were more highly valued than attributes which were perceived to be associated with learning competencies. For each of the 25 attributes surveyed, the actual level of attainment fell below the nominated level of importance. Furthermore, the workplace culture was found to be non-supportive of lifelong learning. All MRS courses in Australia promote lifelong learning as one of their course objectives. There is a general trend towards adopting teaching approaches that promote lifelong learning, while assessment methods that promote and evaluate lifelong learning attributes were lagging behind.These findings have implications for both the MRS workplace and the MRS undergraduate courses in Australia. There needs to be greater ++ / dialogue and collaboration between the MRS employers and the universities to address the gap identified in the attributes. A conceptual model integrating lifelong learning in the context of MRS has been introduced to circumnavigate the predicament felt by most respondents that clinical competency must take precedence over all other attributes. Selection criteria by employers for graduates who are entering the workplace for the first time serve as the vital link between the workplace and the universities. By incorporating lifelong learning attributes as an essential part of the selection criteria, students would come to see the relevance of lifelong learning in their undergraduate training. A learning portfolio can be used as a means of demonstrating that the appropriate learning has taken place. There needs to be a closer link between teaching and assessment by aligning the teaching of lifelong learning objectives and activities with the assessment methods. To this end, it is important that teaching staff must be provided with the appropriate professional support to cultivate lifelong learning attributes and to equip them with the appropriate facilitation skills, before the lecturers can be expected to adopt lifelong learning approaches. This research provides a snapshot of lifelong learning in the MRS profession and should assist in the implementation of lifelong learning strategies that would direct the future of the profession.

During the last decades radiotherapy has made major improvements in accuracy and individualization of the treatment techniques. In this project the thickness of a tungsten filter has been optimized using both simulations and experiments in order to further reduce the uncertainty in the dose given to the patient. With the filter, a dosage with less uncertainty can be obtained and less electrons will strike the patient which means less skin damage. In the simulations a program called PENELOPE, has been used which uses Monte Carlo methods for electron and photons transports. The experiment has been done on real Linear Accelerators.

Medical radiation is estimated to contribute to over 200,000 deaths annually. Recent increases in the use of radiation-producing medical imaging examinations have led to increasing cumulative radiation dose to the general public. Multiple measures have been taken to address this alarming trend, including physician education, technologist education on dose reduction, and equipment-facilitated dose reduction techniques. Shield use can reduce the primary beam by up to 95%. Medical imaging technologists are the primary individuals responsible for applying shielding during an examination. Currently, literature shows that technologists are not shielding individuals as often as they should. After pilot testing, medical imaging technologists were recruited via email to participate in a national cross-sectional survey in September 2017. The survey contained items related to technologists’ demographics, shielding behaviors, and attitudes and beliefs measured at four social-ecological levels – intrapersonal, interpersonal, organizational, and community. The American Registry of Radiologic Technologists (ARRT) provided a list of technologists’ email addresses from their directory. One thousand six-hundred and sixty-one email notifications were sent out in the summer of 2017. Of those, 218 technologists (13%) completed the survey. Among technologists who considered their primary modality to be computed tomography (CT), organizational level factors were a positive significant predictor of shielding behavior. None of the four levels were significant in predicting shielding behavior among diagnostic radiological technologists (x-ray). Individual factors were significantly correlated to shielding behavior among radiologic technologists in the intrapersonal, organizational, and community levels. Study results indicated that interventions implemented at the organizational level may be most effective in increasing shield use among CT technologists. Additional research is needed to better understand factors affecting shield use among medical imaging technologists.