Description
Poster Session with Continuous Refreshments
Mr
Michael Billing
(CLASSE)
10/10/10, 3:30 PM
Poster
During the last several years CESR has been studying the effects of electron clouds on stored beams in order to understand their impact on future linear-collider damping ring designs. One of the important issues is the way that the electron cloud alters the dynamics of bunches within the train. Techniques for observing the dynamical effects of beams interacting with the electron clouds have...
Mr
Nathan Rider
(Cornell)
10/10/10, 3:30 PM
Poster
The research focus of the CESR Test Accelerator program requires new instrumentation hardware, software and techniques in order to accurately investigate beam dynamics in the presence of electron cloud effects. These new instruments are also required to develop low emittance beam conditions which are key to the success of the damping ring design for the International Linear Collider. This...
Mr
David Rubin
(Cornell University)
10/10/10, 3:30 PM
Poster
Low emittance tuning and characterization of electron cloud phenomena are central to the CesrTA R&D program. A small vertical emittance is required in order to be sensitive to the emittance diluting effects of the electron cloud. We have developed techniques to systematically and efficiently eliminate optical and alignment errors that are the sources of vertical emittance. Beam based...
Marco Venturini
(LBNL)
10/10/10, 3:30 PM
Poster
One of the options considered for a future aupgrade of the LHC injection
complex entails the replacement of PS with PS2, a larger
circumference and higher-energy synchrotron. Electron cloud has been identified
as a potential limitation to the machine performance. We review
studies of e-cloud build-up and present recent results of simulations of short-term
e-cloud effects on the...
Jim Crittenden
(Cornell University)
10/10/10, 3:30 PM
Poster
The Cornell Electron Storage Ring Test Accelerator (CesrTA) program includes
investigations into electron cloud buildup, applying various mitigation
techniques in custom vacuum chambers.
Among these are two 1.1-m-long sections located
symmetrically in the east and west arc regions. These chambers
are equipped with pickup detectors shielded against
the direct beam-induced signal. They...
Dr
Yulin Li
(CLASSE, Cornell University)
10/10/10, 3:30 PM
Poster
The vacuum system of Cornell Electron Storage Ring (CESR) was successfully reconfigured to support CesrTA physics programs, including electron cloud (EC) build-up and suppression studies. One of key features of the reconfigured CESR vacuum system is the flexibility for exchange of various vacuum chambers with minimized impact to the accelerator operations. This is achieved by creation of...
Mr
Jin-Sung Kim
(Cornell University)
10/10/10, 3:30 PM
Poster
Measuring secondary electron yields (SEYs) on technical surfaces in accelerator vacuum systems provides essential information for many accelerator R&D projects, such as the ILC Damping Rings, regarding to electron cloud growth and suppression. As a part of CesrTA research program, we developed and deployed SEY in-situ measurement systems. Two such SEY systems were installed to expose samples...
Joseph Calvey
(LEPP, Cornell University)
10/10/10, 3:30 PM
Poster
A great deal of Retarding Field Analyzer (RFA) data has been taken as part of the CesrTA program at Cornell. Obtaining a quantitative understanding of this data requires use of cloud simulation programs, as well as a detailed model of the RFA itself. In some cases the RFA can be modeled by postprocessing the output of a simulation codes, and one can obtain “best fit” values for important...
Kiran Sonnad
(Cornell University)
10/10/10, 3:30 PM
Poster
In this presentation, we will report the progress made in the past few years
on simulations to study the electron cloud effects on the dynamics of beams
in cicular accelerators. Results associated with various acclerators such as
the Fermilab Main Injector, SPS, LHC, ILC damping rings will be shown.
Comparisions between the results obtained from three codes, namely Warp, HeadTail
and...
Kiran Sonnad
(Cornell University)
10/10/10, 3:30 PM
Poster
The simulation code VORPAL has been used as a tool to study charecteristics of
TE wave transmission in the presence of electron clouds for CesrTA. We look at
how the electron cloud induced phase shift is influenced by (1) reflections of the
wave, caused by possible protrusions in the beam pipe and (2)effect of nonuniformities
of the cloud density distribution in the transverse plane. ...
Gerry Dugan
(Cornell University)
10/10/10, 3:30 PM
Poster
As part of the Bmad software library, a program called Synrad3d has been written to track synchrotron radiation photons generated in storage rings. The purpose of the program is primarily to estimate the intensity and distribution of photon absorption sites, which are critical inputs to codes which model the growth of electron clouds. Synrad3d includes scattering from the vacuum chamber walls...
Mr
John Sikora Sikora
(CLASSE, Ithaca, NY)
10/10/10, 3:30 PM
Poster
TE Wave measurement systems have been installed in the L0 and L3 regions of CesrTA. L0 is the location of 6 superconducting wiggler magnets; L3 has round beampipe through a chicane magnet (PEPII) and a NEG coated chamber. At both locations, rf relays are used to multiplex signals from a signal generator output, through the beampipe, and to the input of a spectrum analyzer. Software monitors...
Dr
David Kreinick
(Cornell University)
10/10/10, 3:30 PM
Poster
One technique used at CesrTA for studying the effects of electron clouds
on beam dynamics is to measure electron and positron bunch tunes under
a wide variety of beam energies, bunch charge, and bunch train
configurations. Comparing the observed tunes with the predictions of
various simulation programs allows the evaluation of important
parameters in the cloud formation models. These...
