Design of the SSC linac
The preliminary design of the 600-MeV H/sup -/ linac for the Superconducting Super Collider (SSC) injector is described. The linac must provide a 25-mA beam during 7-35 mu s macropulses at 10 Hz within injection bursts. Normalized transverse emittances of less than 0.4 pi mm-mrad (RMS) are required for injection into the low Energy Booster (LEB) synchrotron. Cost, ease of commissioning, and operational reliability are important considerations. The linac will consist of an H/sup -/ source with electrostatic low-energy beam transport (LEBT), a 2.5-MeV radiofrequency quadrupole (RFQ) accelerator, a 70-MeV drift-tube linac (DTL), and 530 MeV of coupled-cavity linac (CCL). The RFQ and DTL operate at 428 MHz and the CCL operates at 1284 MHz. A modest total length of 143 m results from the tradeoff between cost optimization and reliability.<<ETX>>
A 50-mA Negative Hydrogen-Ion Source
An ion source of the magnetron type, which produces a 50-mA negative hydrogen-ion beam of good quality for accelerator injection, has been developed. This source has been in use for over a year and has become the principal ion source for all modes of accelerator operation at Fermilab. Details of the design and operation of this source along with information regarding beam quality and reliability are presented.
Optimization of H− production in a magnetically filtered multicusp source
Different techniques to increase the H− yield in a multicusp source have been investigated. It is shown that the extracted H− current can be enhanced by optimizing the discharge voltage, the neutral gas pressure, or by employing a magnetoelectrostatic containment scheme. A factor of 6 increase in H− output has been achieved by placing the extractor very close to the magnetic filter. It is also found that the extracted electron current is much reduced at this optimum geometry.