LBNL, Berkeley, California
Funding: This work is supported by the Director, Office of Science, U. S. Department of Energy under Contract No. DE-AC02-05CH11231.
In 2006, the 30mm period In-Vacuum Insertion Device (IVID) was operational for the femtosecond phenomena beamline at the Advanced Light Source (ALS) of Lawrence Berkeley National Laboratory. Since then the IVID has been demonstrating unexpected behaviors especially at small gaps (minimum gap = 5.5mm). The main observations related to these issues are partial or total beam losses as well as sudden pressure increases while operating the IVID gap. This paper is reporting these observations and describes the investigations and the repair attempt performed on this insertion device.
LBNL, Berkeley, California
BNL, Upton, Long Island, New York
Funding: Supported by DOE BES contract DE-AC03-76SF00098.
Several years ago experiments at the APS demonstrated the possibility of creating crabbed beam through vertically kicking the beam and letting it oscillate for a half of a synchrotron period. Such a crabbed beam would allow the possibility of creating a few ps xrays. At the ALS we have repeated these experiments. In this paper we will present the results obtained and compare them to theoretical predictions.
LBNL, Berkeley, California
Funding: Supported by the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
ALS has been upgraded by adding Top-Off Mode, a new mode of operation to the existing modes of Fill and Stored Beam. The Top-Off Mode permits injection of 1.9GeV electron beam into the Storage Ring, with the safety shutters open, once certain strict conditions are met and maintained. Top-Off Mode enables User operation without an interruption caused by mode switching between the Stored Beam Mode when safety shutters are open, to the Fill Mode with the safety shutters closed and back. The conditions necessary to permit Top-Off Mode are; stored beam is present, the energies are matched between the injector and storage ring, a select set of storage ring lattice magnets are operating at the correct current levels, and radiation losses are minimized. If certain combinations of these conditions are not met, a potentially dangerous condition of injecting electrons down a users beam line can exist. Therefore a system of mode control, energy match, lattice match and stored beam interlocks are needed to control the injected beam prohibiting potentially dangerous conditions. In this paper we will present the Top-Off Mode Beam Interlock system requirements, design, and operational parameters.
LBNL, Berkeley, California
Funding: This work was supported by the Director, Office of Science, U. S. Department of Energy under Contract No. DE-AC02-05CH11231.
The upgrade of the Advanced Light Source to enable top-off operation has been ongoing for the last four years. Activities over the last year have centered around radiation safety aspects, culminating in a systematic proof that top-off operation is equally safe as decaying beam operation, followed by commissioning and full user operations. Top-off operation at the ALS provides a very large increase in time-averaged brightness to ALS users (by about a factor of 10) as well as improvements in beam stability. The presentation will provide an overview of the radiation safety rationale, commissioning results, as well as experience in user operations.
LBNL, Berkeley, California
Funding: Work supported by the Director, Office of Science, U. S. Department of Energy under Contract No. DE-AC02-05CH11231.
Multiobjective optimization has been used in many fields including accelerator related projects. Here we use it as a powerful tool for lattice design and optimization, which includes betatron functions, brightness.
LBNL, Berkeley, California
Funding: Supported by DOE BES contract DE-AC03-76SF00098.
Recently there has been a proposal to use pulsed high order multipole elements for injection. One of the advantages of this proposed injection scheme would be that it would be less disruptive to the stored beam and thus advantageous for Top-off operation. In addition to Top-off, such novel injectors might open the door to operating storage rings in more desirable lattice settings. In this paper we will explore some of the possibilities for taking advantage of high order multipole pulsed kick injection.