Application of a Crystal Septum to Replace a Magnet in a Charged Particle Beam and Study of Dechanneling and Feeding in Effects in a Single Silicon Crystal

Thesis/Dissertation · Wed May 01 04:00:00 EDT 1985

DOI:https://doi.org/10.2172/1375775· OSTI ID:1375775

Wijayawardana, Ranjith Laxman ^[1]

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1. State Univ. of New York (SUNY), Albany, NY (United States)

First part of this thesis describes the first application of a crystal septum to replace a magnetic septum at the Fermilab Meson area M-Bottom secondary beam line. As a result the maximum momentum of the beam that could be transmitted to the experimental area was raised from the magnetic septum limit of 225 Gev/c to the full primary beam momentum of 400 Gev/c. Transmission properties of the crystal septum has been studied at energies of 60, 100 and 200 Gev/c. Beam properties at 200 Gev/c with the crystal septum operation has also been studied. The second part consists of a study of planar (110) and axial <112> feeding-in and dechanneling effects in a single silicon crystal. Three surface barrier semiconductor detectors along the crystal were used to measure the energy loss of the charged particles. For each particle incident and outgoing angles and the energy losses in the three crystal mounted detectors were recorded on magnetic tapes. Channeled particles were identified by their low energy losses. Data was acquired at energies of 30, 60, 100 and 200 Gev for planar channeling and 60 and 100 Gev for axial channeling. Feeding-in effects were observed for both planar and axial cases. The basic probabilistic equation was used to derive a simple theoretical model which contains the characteristic dechanneling and feeding-in lengths. The dechanneling lengths have been calculated for both planar and axial channeling and the incident angle dependence of of feeding-in has been studied for planar channeling at above all energies.

• Research Organization: Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
• DOE Contract Number: AC02-07CH11359
• OSTI ID: 1375775
• Report Number(s): FERMILAB-THESIS--1985-12; UMI--85-21277; 222266
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS