IPAC2012 - List of Authors (Laface, E.)

Paper

Title

Page

H⁻ and Proton Beam Loss Comparison at SNS Superconducting Linac

1074

A.P. Shishlo, A.V. Aleksandrov, J. Galambos, M.A. Plum
ORNL, Oak Ridge, Tennessee, USA
E. Laface
ESS, Lund, Sweden
V.A. Lebedev
Fermilab, Batavia, USA

Funding: ORNL/SNS is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725.
A comparison of beam loss in the superconducting part (SCL) of the Spallation Neutron Source (SNS) linac for H⁻ and protons is presented. During the experiment the nominal beam of negative hydrogen ions in the SCL was replaced by a proton beam created by insertion of a thin stripping carbon foil placed in the low energy section of the linac. The observed significant reduction in the beam loss for protons is explained by a domination of the intra-beam stripping mechanism of the beam loss for H-. The details of the experiment are discussed, and a preliminary estimation of the cross section of the reaction H⁻ + H⁻ -> H⁻ + H⁰ + e is presented.

Slides TUOBA03 [0.772 MB]

TUPPC080

Investigations of Scaling Laws of Dynamic Aperture with Time for Numerical Simulations including Weak-Strong Beam-Beam Effects

1359

M. Giovannozzi
CERN, Geneva, Switzerland
E. Laface
ESS, Lund, Sweden

A scaling law describing the time-dependence of the dynamic aperture, i.e., the region of phase space where stable motion occurs, was proposed in previous papers about ten years ago. It was shown that dynamic aperture has a logarithmic dependence on time, which would be suggested by some fundamental theorems of the theory of dynamical systems. So far, such a law was applied to single-particle effects only, i.e., the only source of non-linear effects was the magnetic imperfections. In this paper an attempt is made to extend the scaling law to the case of weak-strong beam-beam effects. The results of numerical simulations performed, including both non-linear magnetic imperfections and weak-strong beam-beam effects, are presented and discussed in detail.

THPPP046

ESS End-to-End Simulations: a Comparison Between IMPACT and MADX

3841

E. Laface, R. Miyamoto
ESS, Lund, Sweden
D.C. Plostinar, C.R. Prior
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom

The European Spallation Source will be a 5 MW superconducting proton linac for the production of spallation neutrons. It is composed of an ion source, a radio frequency quadrupole, a drift tube linac and a superconducting linac as well as the low, medium and high, energy beam transport sections. At present these components of the linac are in the design phase: the optimization of the accelerator parameters requires an intensive campaign of simulations to test the model of the machine under possible operational conditions. In this paper the results of simulations performed with the IMPACT and MADX-PTC codes are presented and a comparison is made between them and independent simulations using TraceWin. The dynamics of the beam envelope and single and multi-particle tracking are reported.

THPPP047

The ESS Control Box

3844

E. Laface
ESS, Lund, Sweden
M. Reščič
Cosylab, Ljubljana, Slovenia

The European Spallation Source will be a 5 MW superconducting proton linac, with fixed target, for the production of a stream of neutrons. The entire machine, the target and all the instruments will be controlled by an Integrated Control System: this is a set of hardware and software tools created to provide the most possible easy and flexible interface for the operator daily usage in the control room. The hardware core of the Integrated Control System is the Control Box, a Linux-based computer designed to provide a common platform for the ESS hardware developers. The software front-end for the Control Box is the Experimental Physics and Industrial Control System - EPICS, a standard protocol used to control large facilities such as accelerators or nuclear power plants. In this paper the main characteristics of the Control Box and the EPICS system are presented.

Paper	Title	Page
TUOBA03	H⁻ and Proton Beam Loss Comparison at SNS Superconducting Linac	1074
	A.P. Shishlo, A.V. Aleksandrov, J. Galambos, M.A. Plum ORNL, Oak Ridge, Tennessee, USA E. Laface ESS, Lund, Sweden V.A. Lebedev Fermilab, Batavia, USA
	Funding: ORNL/SNS is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725. A comparison of beam loss in the superconducting part (SCL) of the Spallation Neutron Source (SNS) linac for H⁻ and protons is presented. During the experiment the nominal beam of negative hydrogen ions in the SCL was replaced by a proton beam created by insertion of a thin stripping carbon foil placed in the low energy section of the linac. The observed significant reduction in the beam loss for protons is explained by a domination of the intra-beam stripping mechanism of the beam loss for H-. The details of the experiment are discussed, and a preliminary estimation of the cross section of the reaction H⁻ + H⁻ -> H⁻ + H⁰ + e is presented.
	Slides TUOBA03 [0.772 MB]

TUPPC080	Investigations of Scaling Laws of Dynamic Aperture with Time for Numerical Simulations including Weak-Strong Beam-Beam Effects	1359
	M. Giovannozzi CERN, Geneva, Switzerland E. Laface ESS, Lund, Sweden
	A scaling law describing the time-dependence of the dynamic aperture, i.e., the region of phase space where stable motion occurs, was proposed in previous papers about ten years ago. It was shown that dynamic aperture has a logarithmic dependence on time, which would be suggested by some fundamental theorems of the theory of dynamical systems. So far, such a law was applied to single-particle effects only, i.e., the only source of non-linear effects was the magnetic imperfections. In this paper an attempt is made to extend the scaling law to the case of weak-strong beam-beam effects. The results of numerical simulations performed, including both non-linear magnetic imperfections and weak-strong beam-beam effects, are presented and discussed in detail.

THPPP046	ESS End-to-End Simulations: a Comparison Between IMPACT and MADX	3841
	E. Laface, R. Miyamoto ESS, Lund, Sweden D.C. Plostinar, C.R. Prior STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
	The European Spallation Source will be a 5 MW superconducting proton linac for the production of spallation neutrons. It is composed of an ion source, a radio frequency quadrupole, a drift tube linac and a superconducting linac as well as the low, medium and high, energy beam transport sections. At present these components of the linac are in the design phase: the optimization of the accelerator parameters requires an intensive campaign of simulations to test the model of the machine under possible operational conditions. In this paper the results of simulations performed with the IMPACT and MADX-PTC codes are presented and a comparison is made between them and independent simulations using TraceWin. The dynamics of the beam envelope and single and multi-particle tracking are reported.

THPPP047	The ESS Control Box	3844
	E. Laface ESS, Lund, Sweden M. Reščič Cosylab, Ljubljana, Slovenia
	The European Spallation Source will be a 5 MW superconducting proton linac, with fixed target, for the production of a stream of neutrons. The entire machine, the target and all the instruments will be controlled by an Integrated Control System: this is a set of hardware and software tools created to provide the most possible easy and flexible interface for the operator daily usage in the control room. The hardware core of the Integrated Control System is the Control Box, a Linux-based computer designed to provide a common platform for the ESS hardware developers. The software front-end for the Control Box is the Experimental Physics and Industrial Control System - EPICS, a standard protocol used to control large facilities such as accelerators or nuclear power plants. In this paper the main characteristics of the Control Box and the EPICS system are presented.