Optimization of the SNS neutron beam current

Journal Article · Thu Dec 31 04:00:00 EST 1998 · Transactions of the American Nuclear Society

OSTI ID:298354

Charlton, L A ^[1]

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1. Oak Ridge National Lab., TN (United States)

The proposed Spallation Neutron Source (SNS) facility will consist of two parts: (a) a high-energy (1-GeV) and high-powered (1-MW) proton accelerator (linac) and accumulator ring and (b) a target station that converts the protons to low-energy (<2 eV) neutrons and delivers them to the neutron-scattering instruments. It will be a 60-Hz facility delivering 6 {times} 10{sup 15} protons each second in 60-{micro}s pulses with a linac length of 490 m and an accumulator ring circumference of 220 m. Work is now under way to optimize the neutron beam current. Both the intensity and the time pulse characteristics are important with different requirements for different instruments. The effect of varying the reflector material, the moderator poison location, and the moderator dimensions has been considered. In addition, the impact on the current when a premoderator or a composite moderator is used has been assessed. Two reflector materials were picked to be studied in detail: beryllium and lead. A beryllium reflector gave a greater thermal neutron current but a wider pulse width, with the peak currents about the same. A simple figure of merit (FOM) (intensity/pulse width squared) favored the lead reflector.

• OSTI ID: 298354
• Report Number(s): CONF-981106--
• Journal Information: Transactions of the American Nuclear Society, Journal Name: Transactions of the American Nuclear Society Vol. 79; ISSN 0003-018X; ISSN TANSAO
• Country of Publication: United States
• Language: English

Related Subjects

07 ISOTOPE AND RADIATION SOURCES
43 PARTICLE ACCELERATORS
ACCELERATOR FACILITIES
BEAM CURRENTS
MEASURING INSTRUMENTS
MODERATORS
NEUTRON BEAMS
NEUTRON REFLECTORS
NEUTRON SOURCES
NEUTRON SPECTRA
OPTIMIZATION