ANL, Lemont, Illinois, USA
RadiaSoft LLC, Boulder, Colorado, USA
UCSC, Santa Cruz, California, USA
We present results from a recent collimator irradiation experiment conducted in the Advanced Photon Source (APS) storage ring. This experiment is the third in a series of studies to examine the effects of high-intensity electron beams on potential collimator material for the APS-Upgrade (APS-U). The intent here is to determine if a fan-out kicker can sufficiently reduce e-beam power density to protect horizontal collimators planned for the APS-U storage-ring. The fan-out kicker (FOK) spreads the bunched-beam vertically allowing it to grow in transverse dimensions prior to striking the collimator. In the present experiment, one of the two collimator test pieces is fabricated from oxygen-free copper; the other from 6061-T6 aluminum. As in past studies, diagnostics include turn-by-turn BPMs, a diagnostic image system, fast beam loss monitors, a pin-hole camera, and a current monitor. Post-irradiation analyses employ microscopy and metallurgy. To avoid confusion from multiple strikes, only three beam aborts are carried out on each of the collimator pieces; two with the FOK on and the other with it off. Observed hydrodynamic behavior will be compared with coupled codes.
ANL, Lemont, Illinois, USA
BNL, Upton, New York, USA
The Advanced Photon Source upgrade (APS-U) Multi-Bend Acromat (MBA) storage ring utilizes on-axis swap-out injection requiring up to 20nC charge per electron bunch. Enforcement of radiation safety limits for the new storage ring will be accomplished by a new beam charge monitor interlock that accumulates beam charge measurements in the Booster-to-Storage ring (BTS) transfer line and disables injection when the charge limit over a preset time period is exceeded. The new interlock is based on the existing APS Beam Shut-Off Current Monitor (BESOCM), and incorporates significant improvements over the existing system. New features include use of direct digitization and FPGA processing, extensive remote monitoring capabilities, expanded self-test and fail-safe functions, and the ability to adjust settings and monitor status remotely via EPICS. The new device integrates a test pulse (self-check) feature that verifies the integrity of the integrating beam current transformer (ICT) and cable system used to detect the beam signal. This paper describes the new BTS interlock (BESOCM) design and presents results of bench test and in-machine evaluation of the prototype and production units.