Non linear fields in the SPS and their compensation

Tight tolerances were placed upon non-linearities in the SPS magnet system and sextupoles installed to adjust the chromaticity of the machine. These sextupoles together with octupoles and active damping were used to adjust the SPS beam dynamics and to damp and suppress both multibunch and single bunch transverse instabilities up to 10/sup 13/ protons per pulse. (4 refs)

Rf beam deflection measurements and corrections in the SLC linac

The requirements of rf acceleration in the SLC linac to produce high energy beams are complicated by the presence of small transverse rf beam deflections which arise from several sources. These rf deflections place stringent tolerances on the phase and amplitude stability of the klystrons. They also force the use of special magnetic bumps to correct the trajectories of oppositely charged beams that will pass down the linac. If left unabated, rf deflections can limit the performance of the SLC. There are several methods to reduce the deflections. Many measurements of rf deflections have been made in the low energy part of the linac where the beams are most sensitive. 4 refs., 8 figs., 2 tabs

Infrared Properties of Cataclysmic Variables from 2MASS: Results from the 2nd Incremental Data Release

Because accretion-generated luminosity dominates the radiated energy of most cataclysmic variables, they have been ``traditionally'' observed primarily at short wavelengths. Infrared observations of cataclysmic variables contribute to the understanding of key system components that are expected to radiate at these wavelengths, such as the cool outer disk, accretion stream, and secondary star. We have compiled the J, H, and Ks photometry of all cataclysmic variables located in the sky coverage of the 2 Micron All Sky Survey (2MASS) 2nd Incremental Data Release. This data comprises 251 systems with reliably identified near-IR counterparts and S/N > 10 photometry in one or more of the three near-IR bands.Comment: 2 pages, including 1 figure. To appear in the proceedings of The Physics of Cataclysmic Variables and Related Objects, Goettingen, Germany. For our followup ApJ paper (in press), also see http://www.ctio.noao.edu/~hoard/research/2mass/index.htm

Initial measurements of Z-boson resonance parameters in e+e- annihilation

We have measured the mass of the Z boson to be 91.11±0.23 GeV/c^2, and its width to be 1.61-0.43+0.60 GeV. If we constrain the visible width to its standard-model value, we find the partial width to invisible decay modes to be 0.62±0.23 GeV, corresponding to 3.8±1.4 neutrino species

Observations of accelerated high current low emittance beams in the SLC Linac

The Linac of the SLAC Linear Collider (SLC) is required to accelerate several intense single electron and positron bunches to high energy while not enlarging their small transverse emittances. The improvements needed by the SLAC Linac to meet these goals have very stringent design criteria. As partial systems have become available, beam tests have been performed to confirm the designs. The results of those beam tests are discussed. Future plans of the improvement program are described. 13 refs., 9 figs

(4 HIGH RESOLUTION BEAM PROFILE MONITORS IN THE SLC’

In the SLC linac, low emittance beams with typical transverse dimensions less than 0.2 mm must be accelerated without effective emittance growth. In order to monitor this we have installed a high resolution beam profile monitor system which consists of an aluminum target covered with a fine-grained phosphor, a magnifying optical system, a television camera and video signal recording electronics. The image formed when the beam strikes the phosphor screen is viewed on a CRT monitor at the console and selected horizontal and vertical slices of the beam spot intensity are recorded. A 20 MHz transient waveform recorder is used to sample and digitize the raw video signal along the selected slice. The beam width is determined by fitting the background subtracted data to a Gaussian. Beam spots less than 6 x 3 mm can be viewed. Beam spot size

The rf phase system of the SLC

The phases of the rf throughout the SLC accelerator complex play an important part not only in the energy and energy spread of the beams at the end of the linac, but also in the production process of both electrons and positrons. Proper machine operation requires that certain phase relationships be maintained between the rf systems of the electron source, the electron and positron damping rings, the linac, and the positron source. This paper presents an overview of the interplay of the various rf phases throughout the SLC accelerator complex as well as describing various hardware and software inter-connections which have been made to facilitate control of the system as a whole. In addition, a description is given of rf phase monitoring required for system control. Operational experience and future plans are also discussed. 6 refs., 4 figs