Science/Engineering/Technical forums

Bill has a valid point here, from a physics perspective x-rays, or gamma photons which are scattered for any reason, always have a lower energy than the primary beam, thus for a backscatter system to work, it would have to pick up a very broad spectrum of x-rays, with little or no descrimination ...

Some further notes, and a good link:

If you have chronic back pain, and your doc insists that he needs X-rays, then you can request that a limited series be done, this is 2-3 views instead of the normal 5+ with half of the exposure, and it will give the same end diagnostic result, at a lower price ...

After some recent medical radiation exposure horror stories, the US government is finally talking about mandating the tracking of medical exposure levels. The case in question resulted from a woman seeing 5 doctors, all of which were ordering CT's. Her bone marrow dose was about 25 rem, that's 25 ...

Well in looking for the numbers again to post, I discovered as is often the case, that some one else has been there before, but instead of a "candy wrapper on the ground", I found a nice juicy patent with some real test figures, here it is below. I agree with Doug, about the activation issue of NaI ...

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The conventional activation neutron detection methods tend to use a moderating system, to thermalize the neutrons, for better target isotope absorption. This got me thinking about some more direct method, which takes advantage of a suitable fast neutron reaction, to produce the betas, gammas ...

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I stumbled onto this site, and I really enjoyed using it to research some things, in my case DPF (Dense Plasma Focus). The result was,
that it represented an very real search engine time saver, which allowed me to pretty much read more of what I wanted, best of all without having to click ...

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Just a comment: If your voltage surges way above the X-ray tube rating, then it can arc across the vacuum space between the cathode and anode. With a small amount of stored energy, the tube can often survive. I am just mentioning this because creating what is in essence a superfast switch at ...

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I realize that this will only work with air, but its dirt cheap and easy, its the bone dry air from a scuba tank. I learned this from a local car buff who was looking for a solution for eliminating H2O from the air used to spray the enamel and clear coat onto his cars. The humid air here ...

Hello: Just looking at the physical size of your chamber brought this old reference for a super RF X-ray setup to mind, from the old Berkeley lab. You would have to shield like crazy, or run like hell. It may be handy in a practical sense for radio-chemistry, cross linking of plastics, etc. Or who ...

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Johnf posted something here which I believe is important, and useful enough, to warrant some elaboration. Specifically when he talked about the DP backing vacuum reservoir tank. This volume if sufficient provides a major buffer between the DP and the roughing pump. This is very useful for ...