Muon background in a 1.0-TeV linear collider
The first detailed, quantitative study of muon background in a linear collider was done by G. Feldman in 1988 for the Mark 2 detector at the Stanford Linear Collider (SLC). This followed the observation of an intolerable number of muons coming from beam-halo collimators in the SLC final focus. For his study of the problem, Feldman wrote the program MUCARLO, Version 1.0, which successfully reproduced the experimental results for the number and spatial distribution of muons hitting Mark 2. The background in Mark 2, and subsequently SLD, was reduced to a tolerable level by installing magnetized iron spoilers in the final focus tunnels and by adding beam scrapers in the last three sectors of the linac, approximately 1,500 meters from the collider hall and separated from the detector by the SLC arcs. For application to a true linear collider, MUCARLO was modified to include variable-energy primary beams up to 250 GeV and a linac with optical lattice and waveguide in front of the final focus. More recently the Next Linear Collider (NLC) design group at SLAC has included a collimation system between the linac and final focus which will continuously intercept up to 1% of a 500 GeV beam, or an average power of 84 kW. The collimation system consists of a sequence of six spoiler/total absorber combinations. It is separated from the final focus by a 10-mrad big bend which generates a crossing angle at the IP, allows switching between multiple IPs, and aids muon protection. The main sources of muons for the study described here are the six Hi-Z total absorbers in the collimation system. This study expands on the work in Ref. 1 by including: a 500 GeV beam (instead of 250 GeV); direct e{sup +} annihilation, e{sup +}e{sup {minus}} {r_arrow} {mu}{sup +}{mu}{sup {minus}} and a calculation of muons from photopion production.
- Research Organization:
- SLAC National Accelerator Lab., Menlo Park, CA (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC03-76SF00515
- OSTI ID:
- 10114831
- Report Number(s):
- SLAC-PUB-6385; CONF-9310257-1; ON: DE94005229; TRN: 94:002258
- Resource Relation:
- Conference: 5. international workshop on next-generation linear colliders,Stanford, CA (United States),13-21 Oct 1993; Other Information: PBD: Oct 1993
- Country of Publication:
- United States
- Language:
- English
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