SLAC is developing a long-range plan to transfer the evolving scientific programs at SSRL from the SPEAR3 light source to a much higher performing synchrotron source -- PEP-X -- a new storage ring that would occupy the existing PEP-II tunnel and support two experimental halls, each containing 16 x-ray beam lines. Operating at 4.5 GeV and 1.5 A with a horizontal emittance of 0.14 nm-rad, reached using 90 m of damping wigglers, PEP-X would have an order of magnitude higher average brightness and flux in the 1-{angstrom} x-ray range than any existing or planned future storage ring sources. Higher brightness in the soft x-ray regime might be reached with partial lasing in long undulators, and high peak brightness could be reached with seeded FEL emission. The status of preliminary studies of PEP-X is presented.
The SLAC Beam Physics group and other SLAC collaborators continue to study options for implementing a near diffraction-limited ring-based light source in the 2.2-km PEP-II tunnel that will serve the SSRL scientific program in the future. The study team has completed the baseline design for a 4.5-GeV storage ring having 160 pm-rad emittance with stored beam current of 1.5 A, providing >10{sup 22} brightness for multi-keV photon beams from 3.5-m undulator sources. The team has also investigated possible 5-GeV ERL configurations which, similar to the Cornell and KEK ERL plans, would have {approx}30 pm-rad emittance with 100 mA current, and {approx}10 pm-rad emittance with 25 mA or less. Now a 4.5-GeV 'ultimate' storage ring having emittance similar to the ERL and operating with {approx}200 mA is under study. An overview of the progress of the PEP-X design study and SSRL's plans for defining performance parameters that will guide the choice of ring options is presented.
The PEP-II B-Factory at SLAC (3.1 GeV e{sup +} x 9.0 GeV e{sup -}) operated from 1999 to 2008, delivering luminosity to the BaBar experiment. The design luminosity was reached after one and a half years of operation. In the end PEP-II surpassed, by four times, its design luminosity reaching 1.21 x 10{sup 34} cm{sup -2}s{sup -1}. It also set world stored beam current records of 2.1 A e{sup -} and 3.2 A e{sup +}. Continuous injection was implemented with BaBar successfully taking data. The total delivered luminosity to the BaBar detector was 557.4 fb{sup -1} spanning five upsilon resonances. PEP-II was constructed by SLAC, LBNL, and LLNL with help from BINP, IHEP, the BaBar collaboration, and the US DOE OHEP.
The SUPER-B detector solenoid has a strong 1.5 T field in the Interaction Region (IR) area, and its tails extend over the range of several meters. The main effect of the solenoid field is coupling of the horizontal and vertical betatron motion which must be corrected in order to preserve the small design beam size at the Interaction Point. The additional effects are orbit and dispersion caused by the angle between the solenoid and beam trajectories. The proposed correction system provides local compensation of the solenoid effects independently for each side of the IR. It includes 'bucking' solenoids to remove the solenoid field tails and a set of skew quadrupoles, dipole correctors and anti-solenoids to cancel linear perturbations to the optics. Details of the correction system are presented.
We present an approach for compensating adverse effects of the detector solenoid in the SuperB Interaction Region (IR). We place compensating solenoids around the IR quadrupole magnets to reduce the magnetic fields nearly to zero. This allows more operational headroom for superconducting IR magnets and avoids saturation of ferric IR magnets. We place stronger compensating solenoids between IR magnets to reverse the magnetic field direction. This allows adjusting the total integrated solenoid field to zero, which eliminates coordinate plane rotation and reduces vertical beam displacements in the IR.
SSRL and SLAC groups are developing a long-range plan to transfer its evolving scientific programs from the SPEAR3 light source to a much higher performing photon source that would be housed in the 2.2-km PEP-II tunnel. While various concepts for the PEP-X light source are under consideration, including ultimate storage ring and ERL configurations, the present baseline design is a very low-emittance storage ring. A hybrid lattice has double bend achromat (DBA) cells in two of the six arcs that provide a total 30 straight sections for insertion device (ID) beam lines extending into two new experimental halls. The remaining arcs contain TME cells. Using 90 m of damping wigglers the horizontal emittance at 4.5 GeV would be 100 pm-rad with 1.5-A stored beam. PEP-X will produce photon beams having brightnesses near 10{sup 22} (ph/s/mm{sup 2}/mrad{sup 2}/0.1% BW) at 10 keV. Studies indicate that a 90-m undulator could have FEL gain and brightness enhancement at soft x-ray wavelengths with the stored beam. Crab cavities or other beam manipulation systems could be used to reduce bunch length or otherwise enhance photon emission properties. The present status of the design of PEP-X as a storage ring is presented.
Shortages of {sup 99}Mo, the most commonly used diagnostic medical isotope, have caused great concern and have prompted numerous suggestions for alternate production methods. A wide variety of accelerator-based approaches have been suggested. In this paper we survey and compare the various accelerator-based approaches.