A HYBRID QUADRUPOLE DESIGN FOR THE RAL FRONT END TEST STAND (FETS)

摘要

The Front End Test Stand project being constructed at Rutherford Appleton Laboratory (RAL) aims to deliver a high current (60 mA) H-chopped ion beam, at 3 MeV and 50 pps. The main components of FETS are the H-ion source, the Low Energy Beam Transport line (LEBT), the Radio Frequency Quadrupole (RFQ), the Medium Energy Transport (MEBT) line with beam chopper, as well as a comprehensive set of diagnostics. Space restrictions in the MEBT line place constraints on component length and drive the requirement to identify compact component configurations. A description is given of a novel compact hybrid quadrupole magnet, whose design is based on the concentric combination of a permanent magnet quadrupole (PMQ) and a laminar conductor electromagnetic quadrupole (EMQ). Simulations of magnetic field distribution 3D are presented, and possible applications and further developments are discussed.