Observation of deflection of a beam of multi-GeV electrons by a thin crystal

We report on an experiment performing channeling and volume reflection of a high-energy electron beam using a quasimosaic, bent silicon (111) crystal at the End Station A Test Beam at SLAC. The experiment uses beams of 3.35 and 6.3 GeV. In the channeling orientation, deflections of the beam of 400μrad for both energies with about 22% efficiency are observed, while in the volume-reflection orientation, deflection of the beam by 120μrad at 3.35 GeV and by 80μrad at 6.3 GeV is observed with 86%-95% efficiency. Quantitative measurements of the channeling efficiency, surface transmission, and dechanneling length are taken. These are the first quantitative measurements of channeling and volume reflection using a primary beam of multi-GeV electrons

Spin dynamic tool developments and study regarding the Super-B project

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Parameters for a Super-Flavor-Factory

A Super Flavor Factory, an asymmetric energy e+e- collider with a luminosity of order 10^36 cm-2s-1, can provide a sensitive probe of new physics in the flavor sector of the Standard Model. The success of the PEP-II and KEKB asymmetric colliders in producing unprecedented luminosity above 10^34 cm-2s-1 has taught us about the accelerator physics of asymmetric e+e- colliders in a new parameter regime. Furthermore, the success of the SLAC Linear Collider and the subsequent work on the International Linear Collider allow a new Super-Flavor collider to also incorporate linear collider techniques. This note describes the parameters of an asymmetric Flavor-Factory collider at a luminosity of order 10^36 cm-2s-1 at the Upsilon(4S) resonance and about 10^35 cm-2s-1 at the Tau production threshold. Such a collider would produce an integrated luminosity of about 10,000 fb-1 (10 ab-1) in a running year (10^7 sec) at the Upsilon(4S) resonance.Comment: Flavor Physics & CP Violation Conference, Vancouver, 200

Doubling the PEP-II Luminosity in Simulation

Simulations show that luminosity of the PEP-II B-factory can be doubled from its present peak value of 1 x 10{sup 34}cm{sup -2}s{sup -1}. The particle simulation code BBI developed for studying beam-beam interaction was used to perform the simulations. It was first found that the parasitic collisions significantly degrade the simulated luminosity as the beam currents are increased from 3A and 1.7A to 4A and 2.2A in the low and high energy rings, respectively. The effect of changes in various accelerator parameters on luminosity was then studied in detail from a rough starting point based on analytic estimates and in the process we systematically optimized the luminosity and showed that a luminosity of over 2 x 10{sup 34}cm{sup -2}s{sup -1} is achievable within feasible limits

Interaction region design for a Super-B factroy

We present a preliminary design of an interaction region for a Super-B Factory with luminosity of 1times1036 cm-2 sec-1. The collision has a plusmn17 mrad crossing angle and the first magnetic element starts 0.3 m from the collision point. We show that synchrotron radiation backgrounds are controlled and are at least as good as the backgrounds calculated for the PEP-II accelerator. How the beams get into and out of a shared beam pipe is illustrated along with the control of relatively high synchrotron radiation power from the outgoing beams. The high luminosity makes radiative bhabha backgrounds significantly higher than that of the present B-Factories and this must be addressed as the design is further improved

Optimization of Chromatic Optics Near the Half Integer in PEP-II

The PEP-II collider has benefited greatly from the correction of the chromatic functions. By optimizing sextupole family strengths, it is possible to correct the non-linear chromaticity, the chromatic beta, and the second order dispersion in both the LER and HER. Having implemented some of these corrections, luminosity was improved in PEP-II by almost 10%