3 ms·
No, the modern technique is to calibrate the device, and hence remove any background effects. Low background steel was used to calibrate some parent device, pro
by frozenport 10y ago
No, the modern technique is to calibrate the device, and hence remove any background effects. Low background steel was used to calibrate some parent device, probably analog.
- analog31 10y agoYou can subtract the background, but you can't subtract the noise in the background, which goes as the square root of the number of background counts (typical rule of thumb). So you need low background if you want to detect weak signals above background in a finite amount of time.
- Houshalter 10y agoWhy wouldn't it take a finite amount of time? With a large enough sample size, shouldn't any weak effect be distinguishable?
- analog31 10y agoYes, but the sample size might be limited, for instance for the whole body counter shown in the article. Anecdote: One of my friends in grad school was involved in an accident at a national lab, where some radioactive material was released into the air. He had to sit in a thing that counted gamma rays coming from him, to see if he had consumed any of the bad stuff, and it completely enclosed him in a large scintillation detector. So, he was the sample.
- frozenport 10y agoThis is also true, that's why pre-ww2 steel is used by national labs on specialized physics projects. On the other hand I am not aware of commercial medical products that use the stuff.