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Some practical information first - the charged particle beam passing through the matter suffers from energy (and also angular) straggling. That means that even if an ideally monoenergetic beam is used, there will be always a finite volume with Bragg peak losses. The bigger initial energy, the bigger is the volume. Protons stopping at 40 mm have straggling ...


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It might not actually answer your question, but to throw it into the bowl: There are some advances in MRI using permanent magnets and even conventional electromagnets with static magnetic fields of about 0.5 Tesla. As far as I know one can do imaging with a reasonable resolution with these devices without the need for extensive cooling. They are used for ...


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If you are asking about cancers such as leukemia the general consensus in the scientific and medical communities is that to date there is no evidence of increased risk due to exposure to high voltage powerlines, mobile phones or wifi. The main risks around high voltage power lines are due to high electric field gradients, especially at close vicinity such ...


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The dose that kills a tumor is deliberately aimed at that tumor. If, instead of using a collimated beam, you put a person in a wide beam for radio "therapy", you would be treating their entire body as a tumor and kill them. The dose in RT is computed locally - "this" part of the body (these grams of tissue) absorbed (were exposed to) "this many" Joules of ...


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If you pump gas along a pipe then pressure drop per unit length of the pipe depends on the diameter of the pipe. The smaller the pipe the harder it is to pump the gas through it. The pressure drop is given by the Darcy-Weisbach equation: $$ \Delta P = f_D \frac{\rho v^2}{2} \frac{\ell}{d} $$ though with the complication that the density of the gas depends ...


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Everyone is likely to have a similar pain threshold to electric shocks. If your friend wears leather soled shoes he will conduct static electricity to earth because they offer much less resistance to earth than rubber or plastic soled shoes. Wearing synthetic clothes may cause a similar effect. If he/she has lower resistance than you (by having sweaty ...


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I am a medical physicist working in a Radiation Oncology department. MLCs are used for both 3D and IMRT plans. In fact, very few hospitals have the ability to make/use the lead blocks anymore. The MLCs define the shape of the radiation field. 3D treatment plans are generated with the user (often the MD) defining the MLC shapes for each gantry angle, and ...


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Percentage Depth Dose Curves (or PDDs) are used to determine how many Monitor Units (MU) a treatment machine needs to give (or how long the machine needs to be on) to deliver a particular dose to a particular depth. The depth at which the PDD curve peaks is referred to as dmax. Treatment machines are often calibrated so that 1MU = 1 cGy at dmax in water. ...



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