ANL, Argonne, USA
Presently, APS utilizes one simple canting scheme to separate radiation generated by two insertion devices (IDs) located in the same ID straight section. This scheme is based on triangular horizontal orbit bump with one corrector located between the IDs and orbit distortion limited to the ID straight section only. However, this scheme does not allow for switching between the upstream and downstream devices, nor does it allow for one beamline to accept the combined radiation of both devices. Yet these capabilities are being requested for the future APS Upgrade. In this paper, we describe more advanced canting schemes that allow for these capabilities. The main complication here is that the orbit distortion is required to go through the storage ring magnets thus generating optics errors, which have to be corrected.
ANL, Argonne, USA
Purdue University, West Lafayette, Indiana, USA
The first prototype superconducting undulator (SCU0) was successfully installed and commissioned at the Advanced Photon Source (APS) and is delivering photons for user science. All the requirements before operating the SCU0 in the storage ring were satisfied during a short but detailed beam commissioning. The cryogenic system performed very well in the presence of the beam. The total beam-induced heat load on the SCU0 agreed well with the predictions, and the SCU0 is protected from excessive heat loads through a combination of orbit control and SCU0 alignment. When powered, the field integral measured with the beam agreed well with the magnet measurements. An induced quench caused very little beam motion, and did not cause loss of the beam. The device was found to quench during unintentional beam dumps, but quench recovery is transparent to storage ring operation. There were no beam chamber vacuum pressure issues and no negative effect observed on the beam. Finally, the SCU0 was operated well beyond its design requirements, and no significant issues were identified. The beam commissioning results are described in this paper.
ANL, Argonne, USA
As part of the Advanced Photon Source (APS) Upgrade, new x-ray beamline front ends are planned that include extensive integrated x-ray diagnostic capability. The design includes a grazing-incidence insertion device x-ray beam position monitor (GRID-XBPM) based on Cu K-edge x-ray fluorescence from x-rays striking a pair of copper absorbers. At a 1.0-degree grazing incidence angle, the XBPM assembly was designed to withstand two inline Undulator A devices operating at 150-mA beam current, a total power of 16 kW. A second x-ray BPM located outside of the accelerator enclosure monitors back fluorescence from the beamline exit mask, which is a critical beamline-defining aperture. In addition, an intensity monitor is used to detect x-ray flux passing through a front-end mask inside the enclosure, while a second intensity monitor is located immediately downstream of the exit mask. Details of these designs and expected performance will be presented.
ANL, Argonne, USA
The APS upgrade includes improvements to the Bergoz Multiplexed BPM system, which presently suffers from an aging data acquisition system. The upgrade leverages off the development of an eight-channel data acquisition system featuring modern FPGA flexibility that was designed for the monopulse BPM system. This upgrade also provides an external clock signal synchronized to the APS revolution clock that will eliminate the aliasing caused by the Bergoz asynchronous multiplexing interacting with different accelerator fill patterns. The upgrade will revitalize this system and demonstrate a cost-effective approach to improved beam stability, reliability, and enhanced postmortem capabilities. In this paper we will discuss the upgrade system specifications, design, and prototype test results.
ANL, Argonne, USA
A real-time feedback double sector controller (RTFB DSC) for the APS Upgrade has been under design for the past year. Using the Xilinx Zynq-7000 All Programmable System on a Chip FPGA residing on the ZC706 board as the base platform, the upgrade path interfaces to the existing accelerator system and modernizes the beam position monitoring and feedback systems. The modernized system increases the RTFB system sample rate from 1.5 kHz to 22.6 kHz. We report the plan for sector-by-sector upgrades that will occur during system shutdowns and allow the upgraded sectors to operate with the existing sectors. The mapping of the RTFB DSC architecture is shown utilizing the targeted FPGA features. These features include the dual ARM CortexTM-A9 processors, multi-port DDR3 memory controllers, gigabit transceivers, and the programming logic interconnect for implementing advanced orbit feedback controller algorithms using floating-point DSP operations. The RTFB DSC FPGA architecture is revealed as well as subsequent progress on the chassis implementation.