Testing and Implementation Progress on the Advanced Photon Source (APS) Linear Accelerator (Linac) High-Power S-band Switching System

An S-band linear accelerator is the source of particles and the front end of the Advanced Photon Source injector. In addition, it supports a low-energy undulator test line (LEUTL) and drives a free-electron laser (FEL). A waveguide-switching and distribution system is now under construction. The system configuration was revised to be consistent with the recent change to electron-only operation. There are now six modulator-klystron subsystems, two of which are being configured to act as hot spares for two S-band transmitters each, so that no single failure will prevent injector operation. The two subsystems are also used to support additional LEUTL capabilities and off-line testing. Design considerations for the waveguide-switching subsystem, topology selection, control and protection provisions, high-power test results, and current status are describedComment: Linac 2000 paper No. THE07 3 pages with 3 figure

APS storage ring vacuum system performance

The Advanced Photon Source (APS) storage ring was designed to operated with 7-GeV, 100-mA positron beam with lifetimes > 20 hours. The lifetime is limited by residual gas scattering and Touschek scattering at this time. Photon-stimulated desorption and microwave power in the rf cavities are the main gas loads. Comparison of actual system gas loads and design calculations will be given. In addition, several special features of the storage ring vacuum system will be presented

Status of the APS diagnostics undulator beamline

We report the status of the diagnostics undulator beamline for the Advanced Photon Source (APS) storage ring. The beamline was designed for the characterization of the 7-GeV, low-emittance positron beam at high resolution. The special diagnostics undulator has been manufactured by STI Optronics. The device exhibits very low magnetic field errors at closed gap of 10.5 mm: first field integral less than 15 gauss{center_dot}cm, and optical phase error less than 1.5{degrees}. The front end of the beamline and a monochromator are installed and tested for use on divergence and directional stability measurements with a target resolution of 3 {mu}rad utilizing the first harmonic radiation of 25 keV. Initial results for the divergence measurement show that the storage ring is operating well within its design goals

APS storage ring vacuum system development

The Advanced Photon Source synchrotron radiation facility, under construction at the Argonne National Laboratory, incorporates a large ring for the storage of 7 GeV positrons for the generation of photon beams for the facility's materials research program. The Storage Ring's 1104 m circumference is divided into 40 sectors which contain vacuum, beam transport, control, rf and insertion device systems. The vacuum system will operate at a pressure of 1 nTorr and is fabricated from aluminum. The system includes distributed NeG pumping, photon absorbers with lumped pumping, beam position monitors, vacuum diagnostics and valving. An overview of the vacuum system design and details of selected development program results are presented. 5 refs

Development of the low return loss 340-size ceramic window for the APS linac.

The Advanced Photon Source (APS) linac high-power switching system makes use of 340-size waveguide components. These components include vacuum-grade furnace-brazed transitions, pressurized-grade aluminum 340-size switches, and more recently 340-size ceramic windows. The fabrication of these 340-size windows proceeded with brazing of ceramic membrane to thin-walled copper sleeves and real-time network analyzer testing performed by the ASD (Accelerator Systems Division) RF (Radio Frequency) Group. Initially it was thought that this real-time testing of prototype hardware would be necessary in the investigative stage to establish the required dimensions and physical geometry to satisfy the 40-dB return-loss criteria. However, producing four windows now installed involved real-time network analyzer testing during production of each window conducted in parallel with adjustments of tuners designed into each 340-size ceramic window

Testing and operation of the WR340 waveguide window in the APS linac.

The Advanced Photon Source (APS) linac high-power switching system makes extensive use of SF6 pressurized, WR340-size waveguide, incorporating waveguide switches. A tunable, extra low return loss waveguide window has been developed to support interfacing the pressurized waveguide with the original waveguide, which is under vacuum. The tunable approach is able to consistently achieve a return loss of at least 40 dB. Test and alignment methods, performance, and initial operating experience are described

STATUS OF THE APS DIAGNOSTICS UNDULATOR BEAMLINE

Abstract We report the status of the diagnostics undulator beamline for the Advanced Photon Source (APS) storage ring. The beamline was designed for the characterization of the 7-GeV, low-emittance positron beam at high resolution. The special diagnostics undulator has been manufactured by STI Optronics. The device exhibits very low magnetic field errors at closed gap of 10.5 mm: first field integral less than 15 gauss×cm, and optical phase error less than 1.5°. The front end of the beamline and a monochromator are installed and tested for use on divergence and directional stability measurements with a target resolution of 3 mrad utilizing the first harmonic radiation of 25 keV. Initial results for the divergence measurement show that the storage ring is operating well within its design goals

APS storage ring vacuum system

The Advanced Photon Source synchrotron radiation facility, under construction at the Argonne National Laboratory, incorporates a large ring for the storage of 7 GeV positrons for the generation of photon beams for the facility's experimental program. The Storage Ring's 1104 m circumference is divided into 40 functional sectors. The sectors include vacuum, beam transport, control, acceleration and insertion device components. The vacuum system, which is designed to operate at a pressure of 1 n Torr, consists of 240 connected sections, the majority of which are fabricated from an aluminum alloy extrusion. The sections are equipped with distributed NeG pumping, photon absorbers with lumped pumping, beam position monitors, vacuum diagnostics and valving. The details of the vacuum system design, selected results of the development program and general construction plans are presented. 11 refs., 6 figs., 3 tabs