Then there was a paper which made me quite happy…This paper by Br\u00fblet<\/a>\u00a0discusses in detail how to correct for samples sandwiched between two sample-holder walls. It contains a detailed description of the sample direction-dependent absorption (derived separately in a previous post here<\/a>, and further discussed here for capillaries and spherical samples here<\/a>). It furthermore indicates that you have to be careful with such sandwiched samples, as the sample receives an\u00a0attenuated<\/em>\u00a0\u00a0radiation flux from the first wall. Secondly, the background scattering from the upstream wall is absorbed with direction-dependence by the sample and both walls, the sample-scattered radiation absorbed with direction dependence by the sample and the downstream wall, and the latter again scattering and exhibiting direction-dependent absorption from itself. As you can see, it is a very well put together experimental consideration. Definitely one to add to the reference list!<\/p>\n Lastly I wanted to give a quick update on Bonse Hart instrument construction status. I have been handed a scintillation detector tube to use by one of my advisors. After scrounging through some storerooms in the building, I came across some useful stuff:<\/p>\n The owner was quick to point out that it was slightly aged (15 years) but that I was welcome to take it. I collected the following bits: a NIM bin with some NIM modules (bottom left, the modules are a Tennelec high voltage power supply, Ortec amplifier and NAIG single channel analyser), an oscilloscope (top right), a fancy multimeter (top left) and a power supply (bottom right). The beefy power supply is overkill for powering the small detector preamplifier, but it was what I could find. The NIM stuff, for those not familiar with it, is a modular system for analog signal processing<\/a> developed in the 1960’s. It can house a wide variety of modules, each geared towards a specific task. I am still missing two modules: a pulse counter and a ratemeter (which come at about 5 kEuro each), but I figure I may abuse an Arduino Uno<\/a> to do those tasks for me if I do not stumble across another stash somewhere. Still, I am very happy to have come across the most tricky bits. Soon I will get the chance to try it all out! See you then!<\/p>\n","protected":false},"excerpt":{"rendered":"![\"Scrounged](\"http:\/\/www.lookingatnothing.com\/wp-content\/uploads\/2013\/05\/detector_stuff-e1368430383204.jpg\")
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