Difference between revisions of "Detectors"

Revision as of 14:26, 6 September 2010

11C Identification and Measurement

Use 2 2" Sodium Iodide detectors. Manuafacturer is Bicron, now part of Saint-Gobain These detectors have thin, havar windows because they were originally intended to measure light charged particles (proton, deuteron, triton, alpha) in light fusion reactions Paper from 1986

NaI was one of the first inorganic scintillators discovered (reference) and is still widely used for x-ray and gamma ray detection. It has good "stopping power" or long "radiation length", ie, good ability to stop photons. The energy resolution is poor compared to CsI or BaF2 and is not even in the same league as HPGe. However, it is better than most organic scintillators.

The NaI scintillates in the (blue/uv/don't remember) and so is coupled to a photomultiplier with a (don't know) window. The PMT acts to increase convert the scintillation light into electrons then multiply the electron current until it is large enough for us to amplify or observe.

PMT

Tube BAse, Anode, dynode outs (these also have connections for Peltier Coolers Do NOt follow this link!!!

NIM Bin

HV Power supply for Tube Base

Spectroscopy Amplifier, Unipolar + Bipolar outs, concept of GAin

Discriminator, CFD

Coincidence, Counter Timer