LANL, Los Alamos, New Mexico
Large maintenance dose burdens have necessitated the development of radiation resistant water manifolds for use on DC magnets in the Proton Storage Ring, at the Los Alamos Neutron Science Center (LANSCE) accelerator. This paper will describe dose measurements and the mechanical design of radiation resistant water manifolds used in PSR.
LANL, Los Alamos, New Mexico
Dose rate modeling and post irradiation measurements of the Isotope Production Facility beamline, at the Los Alamos Neutron Science Center (LANSCE) accelerator, have determined that a radiation shielding shutter is required to protect personnel from shine from irradiated targets for routine beam tunnel entries. This paper will describe radiation dose modeling, shielding calculations and the failsafe mechanical shutter design.
LANL, Los Alamos, New Mexico
ORNL, Oak Ridge, Tennessee
LANL, Los Alamos, New Mexico
University of Tennessee, Knoxville, Tennessee
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
KEK, Ibaraki
Diamond stripping foils are under development for the SNS. Free-standing, flat 350 microgram/cm2 foils as large as 17 x 25 mm have been prepared. These nano-textured polycrystalline foils are grown by microwave plasma-assisted chemical vapor deposition in a corrugated format to maintain their flatness. They are mechanically supported on a single edge by a residual portion of their silicon growth substrate; typical fine foil supporting wires are not required for diamond foils. Six foils were mounted on the SNS foil changer in early 2006 and have performed well in commissioning experiments at reduced operating power. A diamond foil was used during a recent experiment where 12 microCoulombs of protons, approximately 40% of the design value, were stored in the ring. A few diamond foils have been tested at LANSCE/PSR, where one foil was in service for a period of five months (820 Coulombs of integrated injected charge) before it was replaced. Diamond foils have also been tested in Japan at KEK (650 keV H-) where their lifetimes slightly surpassed those of evaporated carbon foils, but fell short of those for Sugai's new hybrid boron carbon (HBC) foils.
TechSource, Santa Fe, New Mexico
LANL, Los Alamos, New Mexico
SLAC, Menlo Park, California
Recent beam physics studies on the two-stream e-p instability at LANL proton storage ring (PSR) have focused on the role of the electron cloud generated in quadrupole magnets where electrons, which seed beam-induced multipacting, are expected to be largest due to grazing angle losses from the beam halo. A new diagnostic to measure electron cloud formation and trapping in a quadrupole magnet has been developed, installed, and successfully tested at PSR. Experimental results will be presented on various characteristics of electron cloud obtain from experiments using this diagnostic and compared with simulations. Results include data on flux and energy spectra of electrons striking the vacuum chamber, the line density and lifetime of electrons trapped in the quadrupole after the beam has been extracted as well as evidence regarding electrons ejected from the magnet during passage of the proton beam.
LANL, Los Alamos, New Mexico
LANL, Los Alamos, New Mexico
Presently, the Los Alamos National Laboratory is in the process of planning a refurbishment of various sub-systems within its Los Alamos Neutron Science Center accelerator facility. A part of this LANSCE facility refurbishment will include some replacement of and improvement to existing older beam diagnostics instrumentation. While plans are still being discussed, some instrumentation that is under improvement or replacement consideration are beam phase and position measurements within the 805-MHz side-coupled cavity linac, slower wire profile measurements, typically known as wire scanners, and possibly additional installation of fast ionization-chamber loss monitors. This paper will briefly describe the requirements for these beam measurements, what we have done thus far to answer these requirements, and some of the technical issues related to the implementation of these instrumentation.
LANL, Los Alamos, New Mexico
TechSource, Santa Fe, New Mexico
In order to better understand the two stream e-p instability issue in the LANSCE Proton Storage Ring, a new diagnostic instrument has been developed to measure the electron cloud formation and trapping in a quadrupole magnet at the LANSCE, PSR. The device called the Electron Cloud Detector (ECD) was fabricated and has successfully been installed in the PSR. Along with the Electron Cloud Detector, an additional device was developed to manipulate electrons ejected from the quadrupole and allow additional information to be obtained from ECD measurements. This paper will discuss the mechanical design and fabrication issues encountered during the course of developing both devices.
LANL, Los Alamos, New Mexico
A prototype Beam Position and Phase Monitor (BPPM) beam line device is being designed to go in the LANSCE 805-MHz linac. The concept is to install two beam line devices in locations where their measurements can be compared with older existing Delta-T loop and wire scanner measurements. The plan is to install two devices so that transverse position, angular trajectory, as well as central beam phase and energy will be measured. The mechanical design will combine features from previous LANL designs that were done for the LANSCE Isotope Production Facility, LANSCE Switchyard project, and those done for the SNS linac. This paper will discuss the mechanical design and fabrication issues encountered during the course of developing the BPPM.