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Status of SLC

Description: The current construction status of the Stanford Linear Collider (SLC) is described along with a brief overview of the project. Tests of completed parts of the machine are summarized.
Date: May 1, 1985
Creator: Ecklund, S.D.
Partner: UNT Libraries Government Documents Department

Survey of beam instrumentation used in SLC

Description: A survey of beam instruments used at SLAC in the SLC machine is presented. The basic utility and operation of each device is briefly described. The various beam instruments used at the Stanford Linear Collider (SLC), can be classified by the function they perform. Beam intensity, position and size are typical of the parameters of beam which are measured. Each type of parameter is important for adjusting or tuning the machine in order to achieve optimum performance. 39 refs.
Date: March 1, 1991
Creator: Ecklund, S.D.
Partner: UNT Libraries Government Documents Department

The high-gradient S-band linac for initial acceleration of the SLC (SLAC linear collider) intense positron bunch

Description: Although short lengths of S-band standing-wave, disk-loaded waveguide have been successfully RF-processed to accelerating gradients equivalent to about 175 MeV/m in a traveling-wave structure, the 20 MeV/m gradient of the SLC 50 GeV linac has been the highest gradient S-band accelerator in operation. However, the 1.5 m traveling-wave constant impedance capture section for the SLC positron source, operating with a dedicated 60 MW klystron, is now routinely accelerating single-bunch beams of more than 7 /times/ 10/sup 10/ e/sup +//pulse at rates of up to 60 Hz with an accelerating gradient section are described. 11 refs., 1 fig. 1 tab.
Date: August 1, 1989
Creator: Clendenin, J.E.; Ecklund, S.D. & Hoag, H.A.
Partner: UNT Libraries Government Documents Department

SLC positron source pulsed flux concentrator

Description: SLC positron beams produced by a high energy electron beam, impinging on a high Z target, have initially small transverse size but large divergence, a situation ill matched to the following S-band accelerator. The flux concentrator is an adiabatic matching device placed between the target and this accelerator, which trades divergence versus size. It produces a magnetic field with a sharp rise over less than 5 mm to its peak value, and then falling off adiabatically over 10 cm. It is a 12 turn, 10 cm long copper coil with a cylindrical outside radius of 4 cm and a conical inside radius growing from 3.5 mm to 2.6 cm. The 0.2 mm gaps between the individual windings were manufactured by electric discharge machining out of one copper block. Excitation current and water cooling is provided by a hollow rectangular copper conductor brazed to the outside of the coil (also 12 turns). The pulsed magnetic field has a maximum strength of 58 kG at 16 kA. At the terminals, the coil has an inductance of 0.8 {mu}H. Current shape is a half sinusoidal wave with a bottom width of 5 {mu}s, and the system operates at a repetition rate of 120 Hz. The coil has only one supporting ceramic insulator at the low voltage front end. The flux concentrator has improved the positron yield approximately 3 times and had no failure in operation during several years. 10 refs., 5 figs.
Date: June 1, 1991
Creator: Kulikov, A.V.; Ecklund, S.D. & Reuter, E.M.
Partner: UNT Libraries Government Documents Department

Isochronous 180 degree turns for the SLC positron system

Description: The design of the compact, achromatic, second order isochronous 180{degrees} turn for the SLC positron transport system will be described. Design criteria require an energy range of 200{plus minus}20 MeV, energy acceptance of {plus minus}5%, transverse admittance of 25{pi} mm-mr, and minimal lengthening of the 3 to 4 mm (rms) positron bunch. The devices had to fit within a maximum height or width of about 10 ft. Optics specifications and theoretical performance are presented and compared to experimental results based on streak camera measurements of bunch length immediately after the first isochronous turn (200 MeV) and positron beam energy spread after S-band acceleration to 1.15 GeV. 5 refs., 7 figs.
Date: May 1, 1991
Creator: Helm, R.H.; Clendenin, J.E.; Ecklund, S.D.; Kulikov, A.V. & Pitthan, R.
Partner: UNT Libraries Government Documents Department

Update on the high-current injector for the Stanford Linear collider

Description: The high current injector has become operational. There are two crucial areas where improvements must be made to meet collider specifications: while the injector can produce up to 10/sup 11/ e/sup -/ in a single S-band bucket, initially much of this charge was captured in a low energy tail and was this not suitable for transport through the accelerator and injection into the damping ring. Pulse to pulse position jitter has been observed, resulting in transverse wake field which increases beam emittance. The problems described above contribute to substantial current loss during transport from the injector (40 MeV) to the SLC damping ring (1.2 GeV). Experimental studies are continuing with the aim of understanding and improving beam characteristics including bunch length, pulse to pulse stability and emittance. The present status of these studies is reported.
Date: March 1, 1983
Creator: James, M.B.; Clendenin, J.E.; Ecklund, S.D.; Miller, R.H.; Sheppard, J.C.; Sinclair, C.K. et al.
Partner: UNT Libraries Government Documents Department

Polarized electron sources for linear colliders

Description: Linear colliders require high peak current beams with low duty factors. Several methods to produce polarized e{sup {minus}} beams for accelerators have been developed. The SLC, the first linear collider, utilizes a photocathode gun with a GaAs cathode. Although photocathode sources are probably the only practical alternative for the next generation of linear colliders, several problems remain to be solved, including high voltage breakdown which poisons the cathode, charge limitations that are associated with the condition of the semiconductor cathode, and a relatively low polarization of {le}5O%. Methods to solve or at least greatly reduce the impact of each of these problems are at hand.
Date: July 1, 1992
Creator: Clendenin, J. E.; Ecklund, S. D.; Miller, R. H.; Schultz, D. C. & Sheppard, J. C.
Partner: UNT Libraries Government Documents Department

The NLC positron source

Description: A baseline design for the NLC positron source based on the existing SLC positron system is described. The proposed NLC source consists of a dedicated S-band electron accelerator, a conventional positron production and capture system utilizing a high Z target and an adiabatic matching device, and an L-band positron linac. The invariant transverse acceptance of the capture system is 0.06 m{center_dot}rad, ensuring an adequate positron beam intensity for the NLC.
Date: May 1, 1995
Creator: Tang, H.; Kulikov, A.V.; Clendenin, J.E.; Ecklund, S.D. & Miller, R.A.
Partner: UNT Libraries Government Documents Department

Making electron beams for the SLC linac

Description: A source of high-intensity, single-bunch electron beams has been developed at SLAC for the SLC. The properties of these beams have been studied extensively utilizing the first 100-m of the SLAC linac and the computer-based control system being developed for the SLC. The source is described and the properties of the beams are summarized. 9 references, 2 figures, 1 table.
Date: January 1, 1984
Creator: Clendenin, J.E.; Ecklund, S.D.; James, M.B.; Miller, R.H.; Sheppard, J.C.; Sodja, J. et al.
Partner: UNT Libraries Government Documents Department

SLC positron source: Simulation and performance

Description: Performance of the source was found to be in good general agreement with computer simulations with S-band acceleration, and where not, the simulations lead to identification of problems, in particular the underestimated impact of linac misalignments due to the 1989 Loma Prieta Earthquake. 13 refs., 7 figs.
Date: June 1, 1991
Creator: Pitthan, R.; Braun, H.; Clendenin, J.E.; Ecklund, S.D.; Helm, R.H.; Kulikov, A.V. et al.
Partner: UNT Libraries Government Documents Department