A Test Facility for the International Linear Collider, at SLAC End Station a for Prototypes of Beam Delivery and IR Components

Abstract

The SLAC Linac can deliver damped bunches with ILC parameters for bunch charge and bunch length to End Station A. A 10Hz beam at 28.5 GeV energy can be delivered there, parasitic with PEP-II operation. We plan to use this facility to test prototype components of the Beam Delivery System and Interaction Region. We discuss our plans for this ILC Test Facility and preparations for carrying out experiments related to collimator wakefields and energy spectrometers. We also plan an interaction region mockup to investigate effects from backgrounds and beam-induced electromagnetic interference.

Picosecond bunch length and energy-z correlation measurements at SLAC's A-line and end station A

“…As described in [1], bunches of ∼ 2 × 10 10 electrons are accelerated to 28.5 GeV by the SLAC linac, and directed around a 24.5…”

“…In some cases, such as initial beam tuneup, an absolute measurement of the length of the bunch is needed, while in other situations, for example in the case of a feedback system, a relative measurement is satisfactory. This paper addresses two different techniques recently tested at SLAC's End Station A (ESA) [1] to quantify the length of the bunch in that region of the machine. One technique is based on various measurements of the intensity of the radiation in specific frequency bands emitted from ceramic gaps in the beam pipe.…”

Magnetic measurements and simulations for a 4-magnet dipole chicane for the International Linear Collider

“…The SLAC Linac delivers to ESA a 28.5 GeV test beam with similar parameters as the ILC for bunch charge, bunch length and energy spread [1]. ESA beam tests run parasitically with PEP-II with single damped bunches at 10Hz, bunch charge of 1.6 ·10 10 electrons, rms bunch length ~500 microns and rms bunch energy spread ~0.2%.…”

2-D Modeling of Energy-z Beam Dynamics Using the LiTrack Matlab Program

“…At ILC, intense short bunches generate wakefields. Wakefields arise from image charges generated in material (collimators, beampipes) close to the electron bunch [1]. The image charges generate electromagnetic wakefields that act back on the bunch, in particular on the tail of the bunch, increasing both the transverse and longitudinal beam emittance [2].…”

“…Litrack was specifically designed to study the electron beam's longitudinal emittance and how it evolves during beam transport through SLAC's linac [5]. Litrack program can adjust parameters (such as phase of the beam with respect to the accelerating rf in different sections of the Linac) of different beamlines to study the dependence of the bunch length distribution on these (2) LiTrack is run from Matlab, which is an analysis package using linear algebra and matrix manipulation for modeling and creating output files and plots (1).…”