DESIGN REPORT OF A NON–DESTRUCTIVE EMITTANCE INSTRUMENT FOR RUTHERFORD APPLETON LABORATORY’S FRONT END TEST STAND FETS

The RAL front end FETS is currently under construc-tion to demonstrate a fast chopped, high power H − ion beam at 3 MeV of up to 18 kW. Therefore emittance in-struments should use photo detachment because mechani-cal parts could be affected by heat loading. This emittance instrument uses a dipole to separate negative ions from pro-duced neutrals and a scintillator to measure particle distri-bution and deflection. This means a careful design of the diagnostic instrument according to other beam parameters and existing focusing elements because reasonable results require high enough phase space advance. A conceptual design layout will be presented considering the current sta-tus of the MEBT simulations along with a discussion Figure 1: Overview of the FETS set up. The main elements are a Penning type ion source, 3 solenoid LEBT, RFQ and the MEBT consisting of quadrupoles, four buncher cavities and the chopper. The emittance diagnostic and beamdump are located at the end of the beamline