ORBIT CORRECTION IN A NON-SCALING FFAG
EMMA the Electron Model of Many Applications is to be built at the STFC Daresbury Laboratory in the UK and will be the first non-scaling FFAG ever constructed. The purpose of EMMA is to study beam dynamics in such an accelerator. The EMMA orbit correction scheme must deal with two characteristics of a non-scaling FFAG: i.e. the lack of a well defined reference orbit and the variation with momentum of the phase advance. In this study we present a novel orbit correction scheme that avoids the former problem by instead aiming to maximise both the symmetry of the orbit and the physical aperture of the beam. The latter problem is dealt with by optimising the corrector strengths over the energy range.
DIAGNOSTIC SYSTEM COMMISSIONING OF THE EMMA NS-FFAG FACILITY AT DARESBURY LABORATORY FRONT-END
We present a single-shot/turn-by-turn BPM system for the world’s first Non-Scaling FFAG Accelerator ‘EMMA’. To satisfy the requirement of high rate measurement, the BPM system utilizes a front-end conversion of button pickup signals into compact flat-topenvelope 700MHz bursts. This allows also applying timedomain multiplexing into a single channel. In the BPM, both synchronous detector and ADC clocks are directly manufactured from the beam signal. The system architecture is described; BPM features are discussed; initial results of beam tests done on the ALICE injector have been given. mi a low-pass filter are sampled one-byon of the sampling noise generated by A ltage noise which is produced by the jitter of each
Nuclear spin-lattice relaxation in transition metal compounds with local tetragonal symmetry.
We report on the various contributions to the total spin-lattice relaxation rate in metallic materials with local tetragonal symmetry. The analytical formulae are given in the tight-binding approximation. The calculations show the relation between various partial electron densities of states and corresponding contributions to the relaxation rates. The presented formulae can be used to compare theoretically calculated electron band structure parameters with those obtained from NMR spin-lattice relaxation time measurements.