[en] Work on a one interaction-region, push-pull conceptual design for the SLC is described. The concept which has received the most attention is described. It is a below-ground hall - a 15 m deep rectangular pit covered by a surface building which houses counting rooms, power supplies, cryogenics and other auxiliary equipment

[en] At the time of the 1981 Workshop on Experimental Use of the SLC, we published an extraction scheme for the MINIQUAD final focus (FF) optics. Since then a different FF optics design has been selected. With the same achromat section and outboard telescope, it allows a number of options for the inboard telescope. This note describes the new extraction system and briefly considers electron-electron extraction and the consequences of an extraction kicker malfunction. 4 references, 7 figures, 1 table

[en] For sources placed along a 250 GeV linac and final focus lattice, muons from Bethe-Heitler pair production are transported with a Monte Carlo ray-tracing program until they either range out or reach the collider experiment hall. For a muon source located at the entrance to the final focus, a system of toroid spoilers was designed which resulted in one muon in the detector per 3.6 x 10⁷ electrons impinging on the source. This is a factor of 150 improvement over the case when no spoilers are present. 4 refs., 3 figs

[en] 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⁺ annihilation, e⁺e^- → μ⁺μ^- and a calculation of muons from photopion production

[en] Operational activities for the months of August through December 1983, are reported in the areas of accelerator and research operations, research area and experiment status, accelerator improvements, research division developments, PEP division developments, and publications for the month.

[en] The status experimental activities at SLAC is reported, including the long-range schedule and a list of approved high-energy experiments. Work on PEP, SPEAR, and the SLC is included, as well as computing. Such operational data as operating hours and experimental hours are given.

[en] The Program MUCARLO is a computer code developed at the Stanford Linear Accelerator Center (SLAC) to study the muon flux generated from beams of electrons and positrons on various targets. The MUCARLO program has been modified extensively in recent years; this paper describes the latest version. Preliminary results from this code are presented, and compared with results from another (TOMCAT) and with experimental data

[en] A low intensity electron beam parasitic to the operation of the Stanford Linear Collider (SLC) has been transported through the Final Focus Test Beam (FFTB) facility making secondary test beams available for users. Photons generated in collimation of the SLC electron and positron beams in the linac pass through a splitter magnet that deflects the primary beams away from the linac axis into the SLC beam lines. These photons are converted to electrons and positrons in a secondary production target located down beam on the linac axis. The secondary electrons are then transported through the FFTB beam line onto experimental detectors. The average power of the parasitic beam is very low, thus, it presents no hazards. However, various accident scenarios involving failure of the splitter magnet and the active protection devices could send much more powerful SLC beams (up to 90 kilo-watts) into this zero-degree secondary beam line. For the accident cases, the average power in the transmitted beam was calculated using the Monte Carlo programs EGS4 and TURTLE. Results from analysis of the radiation protection systems that assure safety during the parasitic operation are presented

[en] The Lance CO3 carbonaceous chondrite (CC) is less altered than the CI and CM chondrites and so provides a view of the mineralogy and textures resulting from the earliest stages of aqueous alteration of CCs. Matrix olivine in Lance has been partly altered to fine-grained, Fe-bearing serpentine and poorly crystalline Fe³⁺ oxide, a process that required both hydration and oxidation. Serpentine occurs as discrete packets separated from the olivine surfaces by the Fe³⁺ oxide. The Fe released during the dissolution of olivine was partly incorporated into the serpentine; the remainder was oxidized to form Fe³⁺ oxide. Matrix metal was also altered to produce Fe oxides, leaving the residual metal enriched in Ni. Olivine grains in Lance matrix contain channels along their [100] and [001] directions. The formation and convergence of such channels resulted in a grain-size reduction of the olivine. The alteration was pervasive but incomplete, suggesting a limited availability of fluid. A brief study of two other CO chondrites, Kainsaz and Warrenton, shows that these meteorites do not contain phyllosilicates in their matrices, although both contain Fe³⁺ oxide between olivine grains. Prior to its alteration, Lance probably resembled Kainsaz, an unaltered CO3 chondrite. The alteration assemblage in Lance is only slightly different from that in Mokoia and essentially the same as that in C3 xenoliths from Murchison. Alteration products in Lance show greater similarities to CI than to CM chondrites

[en] For sources placed along a 250 GeV linac and final focus lattice, muons from Bethe-Heitler pair production are transported with a Monte Carlo ray-tracing program until they either range out or reach the collider experiment hall. For a muon source located at the entrance to the final focus, a system of toroid spoilers was designed which resulted in one muon in the detector per 3.6 x 10⁷ electrons impinging on the source. This is a factor of 150 improvement over the case when no spoilers are present