An overview of the design of ELIPS-A new slow positron beam line

摘要

In this work, the progress made by the positron group from ELI-NP in the design of a new slow positron beam line is summarized. The rays of a brilliant gamma beam will be used to produce a slow positron beam of high intensity. The main results of the simulations, done for the geometry optimization of the Converter/Moderator Assembly (CMA) for gamma-to-slow e(+) conversion, are reported. By using the gamma-beam with energy of up to 3.5 MeV and intensity of 2.4 x 10(10) gamma s(-1), the slow e(+) beam can be obtained with a maximum intensity of similar to 2 x 10(6) s(-1) with tungsten or platinum CMA. Solid neon moderation is applicable, and a successful implementation will result in a slow e beam of intensity 10(7) s(-1). The CMA can be operated with a central hole (empty set = 2.5 mm) in the foils in parasitic mode, i.e., simultaneously with other gamma-beam experiments, at the cost of reduced intensity by 18%. Furthermore, details on the slow positron transport and the spectroscopic systems, which are under construction, are provided.