Medical physics postgraduate personal statement example

Personal statement example

The first number my final-year project produced was wrong in an interesting way. I had measured how a stack of lead sheets reduced the count rate from a caesium-137 teaching source, fitted an exponential, and found a linear attenuation coefficient noticeably lower than the tabulated value for 662 keV photons. My first assumption was a fault in the scintillation detector. My supervisor suggested I look at the geometry instead. The source, absorber and detector were close together with no collimation, so photons scattered in the lead were still reaching the crystal and being counted. I had measured broad-beam transmission, not the narrow-beam coefficient in the tables. That afternoon introduced me to build-up, and it is the main reason I am applying to study medical physics.

The rest of the project grew from that discrepancy. I made a lead collimator from offcuts in the department workshop and repeated the measurements at several source-to-detector distances. I also restricted the analysis to counts within the photopeak, which reduced the contribution from scattered photons that had lost energy. With a narrow geometry my results came within a few per cent of the reference values. I then plotted the ratio of broad-beam to narrow-beam transmission against absorber thickness to show how build-up increased as the lead got thicker. None of this is new physics, but working out why two careful measurements disagreed taught me more than any single correct answer could have done. My report treated counting statistics, dead time and background subtraction properly, and I learnt to state my uncertainties rather than hide them.

I became interested in where this matters outside a teaching lab. Reading about radiotherapy and diagnostic imaging, I realised that the questions I had struggled with appear constantly there. They include how much scattered radiation reaches a point, how a detector's response depends on energy, and how shielding is specified. My modules in nuclear physics, computational methods and statistical mechanics gave me the theory. A short Monte Carlo exercise in Python, in which I tracked photons through a slab using simple interaction probabilities, showed me how simulation and measurement can check each other. I would like to develop that properly, with realistic tissue models and established simulation tools, and to learn the dosimetry and radiobiology that my degree did not cover.

Outside my course, I work weekends on the reception desk of a busy leisure centre. Much of the job involves explaining booking rules, accessibility options and occasional cancellations to people who are tired or frustrated. I have learnt to give clear information without jargon and to stay accurate when the queue is long. For two years I have also tutored GCSE maths online. Explaining rearranging equations to a fifteen-year-old who has decided she is "bad at maths" has made me better at finding the step where understanding actually breaks down. I expect both skills to matter in a field where physicists work alongside clinicians and talk to patients.

My hobby is repairing second-hand film cameras, mostly mechanical rangefinders bought cheaply because the shutters stick. Testing shutter speeds with a phototransistor and an oscilloscope, then adjusting tension until they are within tolerance, is satisfying in a quieter way than physics coursework. It has also made me patient with small mechanisms and methodical about recording what I change.

I am applying for postgraduate study because I want my physics to be used carefully on problems where accuracy affects people directly. I am comfortable in the laboratory, competent in programming and data analysis, and I take uncertainty seriously. I would bring those strengths to the clinical and research training a medical physics degree provides, and I am keen to learn the parts of the discipline I have so far only read about.