Preliminary results on two-dimensional interferometry of HL Tau

Preliminary two-dimensional speckle interferometry results of HL Tau were found to be qualitatively similar to those found with one-dimensional slit scanning techniques; results consist of a resolved component (approximately 0.7 arcsec in size) and an unresolved component. Researchers are currently reducing the rest of the data (taken on three different telescopes and at three different wavelengths) and are also exploring other high resolution methods like the shift and add technique and selecting only the very best images for processing. The availability of even better two-dimensional arrays within the next couple of years promises to make speckle interferometry and other high resolution techniques very powerful and exiting tools for probing a variety of objects in the subarcsec regime

Muon Collider Overview: Progress and Future Plans

Besides continued work on the parameters of a 3-4 and 0.5 TeV CoM collider, many studies are now concentrating on a machine near 100 GeV that could be a factory for the s-channel production of Higgs particles. We mention the research on the various components in such muon colliders, starting from the proton accelerator needed to generate pions from a heavy-Z target and proceeding through the phase rotation and decay channel, muon cooling, acceleration, storage in a ring and the collider detector. We also mention theoretical and experimental R&D plans for the next several years that should lead to a better understanding of the design and feasibility issues for all of the components. This note is a summary of a report updating the progress on the R&D since the Feasibility Study of Muon Colliders presented at the Workshop Snowmass'96.Comment: 3 pages, 2 figures, LaTex EPAC format; to be published Proceedings of the EPAC98 Conference, Stockholm, Sweden, June 1998. Additional information and articles at http://www.cap.bnl.gov/mumu

The Development of Superconducting Magnets for Use in Particle Accelerators: From the Tevatron to the LHC

Superconducting magnets have played a key role in advancing the energy reach of proton synchrotrons and enabling them to play a major role in defining the Standard Model. The problems encountered and solved at the Tevatron are described and used as an introduction to the many challenges posed by the use of this technology. The LHC is being prepared to answer the many questions beyond the Standard Model and in itself is at the cutting edge of technology. A description of its magnets and their properties is given to illustrate the advances that have been made in the use of superconducting magnets over the past 30 years

The Origination and Diagnostics of Uncaptured Beam in the Tevatron and Its Control by Electron Lenses

In the Collider Run II, the Tevatron operates with 36 high intensity bunches of 980 GeV protons and antiprotons. Particles not captured by the Tevatron RF system pose a threat to quench the superconducting magnet during acceleration or at beam abort. We describe the main mechanisms for the origination of this uncaptured beam, and present measurements of its main parameters by means of a newly developed diagnostics system. The Tevatron Electron Lens is effectively used in the Collider Run II operation to remove uncaptured beam and keep its intensity in the abort gaps at a safe level.Comment: 36 pp, 15 Figs, submitted for publicati5on in Phys. Rev. Special Topics Accel. Beam

Emittance growth mechanisms in the Tevatron beams

In this article we present results of emittance growth measurements in the Tevatron beams. Several mechanisms leading to transverse and longitudinal diffusions are analyzed and their contributions estimated.Comment: 7 p