P. Savage

The design, construction and performance of the MICE scintillating fibre trackers

Charged-particle tracking in the international Muon Ionisation Cooling Experiment (MICE) will be performed using two solenoidal spectrometers, each instrumented with a tracking detector based on 350 mu m diameter scintillating fibres. The design and construction of the trackers is described along with the quality-assurance procedures, photon-detection system, readout electronics, reconstruction and simulation software and the data-acquisition system. Finally, the performance of the MICE tracker, determined using cosmic rays, is presented

The front end test stand high performance H- ion source at Rutherford Appleton Laboratory.

The aim of the front end test stand (FETS) project is to demonstrate that chopped low energy beams of high quality can be produced. FETS consists of a 60 mA Penning Surface Plasma Ion Source, a three solenoid low energy beam transport, a 3 MeV radio frequency quadrupole, a chopper, and a comprehensive suite of diagnostics. This paper details the design and initial performance of the ion source and the laser profile measurement system. Beam current, profile, and emittance measurements are shown for different operating conditions.

Understanding extraction and beam transport in the ISIS H− Penning surface plasma ion sourcea)

The ISIS H(-) Penning surface plasma source has been developed to produce beam currents up to 70 mA and pulse lengths up to 1.5 ms at 50 Hz. This paper details the investigation into beam extraction and beam transport in an attempt to understand the beam emittance and to try to improve the emittance. A scintillator profile measurement technique has been developed to assess the performance of different plasma electrode apertures, extraction electrode geometries, and postextraction acceleration configurations. This work shows that the present extraction, beam transport, and postacceleration system are suboptimal and further work is required to improve it.

RFQ cold model RF measurements and waveguide-to-coaxial line transition design for the front-end test stand at RAL

A 324 MHz four vane RFQ cold model has been built, as part of the development of a proton driver front end test stand at the Rutherford Appleton Laboratory (RAL) in the UK. This paper will present the results of RF measurements performed on the cold model, which include analysis of resonant modes, Q-value measurements and electric field profile measurements using a bead-pull perturbation method. These measurements were done before and after brazing of the four vanes and the results were compared to Microwave Studio simulations. Additionally, a tuner has been designed, built and tested and the results will be presented together with the preliminary results of the electromagnetic design of waveguide-to-coaxial line transition structures for the four vane RFQ.

The ISIS Penning H- SPS and Diagnostic Developments at RAL

This paper covers the recent work carried out at the Rutherford Appleton Laboratory (RAL) on the ISIS Ion Source Development Rig (ISDR). The development of a retarding potential energy analyzer is described and a measured energy spread of 17.6 eV ± 1.5 eV from the ion source is reported. Variation in energy spread versus discharge current is shown. The development of a pepperpot emittance scanner to study emittance variation along the beam axis is discussed.