Studio ed analisi dei livelli di radioattività in un ciclotrone da 70 MeV

Experimental measures (gamma spectrometry with a HPGe detector) and analytical methods were used to quantify the radioactivity induced during the commissioning tests of the 70p cyclotron at LNL (Legnaro National Laboratories) in two samples: 1) a thick copper target used in low current tests for beam extraction at 70 MeV and 1μA and 2) a sample of (DDT) water of the cooling system of a copper beam interceptor used for beam injection tests at 1μA and 70 MeV. It followed a qualitative outline and experimental measurements of the induced activity of a sample of dust, from the accelerator irradiation cave, placed close to the beam line pipe during the proton irradiation at 70 MeV and 100 μA of a copper target shielded with lead and polyethylene. The dose rates from the activities detected on water and dust samples, after the 70p cyclotron commissioning tests, result not relevant from a radiological point of view: they are both less than 10 μSv/y. Whereas the cooling time expected for the copper thick target (or BD) to reach a dose equal to 10 μSv is about 4 days in which it will require monitoring.
The analytical methods used, although based on approximate parameters, were able to give rough estimates of the samples dose rates with the same order of magnitude of the dose rates derived from experimental data.