Application of nuclear reaction analysis for aging investigations of detectors

The article presents a thorough discussion of the applications of the Nuclear Reaction Analysis (NRA) method for investigating aging effects in gas-filled detectors. This technique is particularly efficient in a quantitative evaluation of the presence of light elements (oxygen, carbon, nitrogen, etc.) in the gold coating of the anode wire. The NRA method is also adequate for determining light element distribution with a depth measurement over a range of more than 1 μm. Such data are especially important in studies of gas-discharge avalanche plasmas because they are a starting point for most aging processes. The sensitivity of NRA to these elements is very high—about 5×10−2%. Application of NRA in our aging investigations gave us a reliable confirmation of the key role of oxygen in the wire-swelling mechanism and demonstrated the kinetics of oxygen transport into the depth of the gold coating.