LOW-BETA SC H-CAVITY FOR ESS

At present, many accelerators favour the use of SC cavities as accelerating RF structures. For some of them, like long pulse Spallation Source or Transmutation Facility SC structures might be the only option. Here we present the results of based on spoke cavity geometry multi-cell H-cavity (700 MHz, β=0.2). Some technical details of cavity tuning and manufacturing are discussed. The comparison of numerical simulations with first experimental results of 10-gap H-cavity copper model measurements are shown. 1 H-CAVITY DEVELOPMENT As a first step of an experimental SC H-cavity investigation we plan to build 4-gap 700 MHz, β=0.2 cavity (Fig.1). The detailed results of multy-gap H-cavity geometry optimisation are published elsewhere[1]. The main cavity parameters are summarised in Table 1. Figure 1: 4-gap H-cavity in LHe vessel