IPAC2011 - List of Authors (Rybarcyk, L.)

Paper	Title	Page
MOPC068	LANSCE RF System Improvements for Current and Future Programs*	238
	D. Rees, J.L. Erickson, R.W. Garnett, J.T.M. Lyles, L. Rybarcyk LANL, Los Alamos, New Mexico, USA
	The Los Alamos Neutron Science Center (LANSCE) is in the midst of an upgrade of the RF systems. This project will return LANSCE to its historical operating capability and sustain facility operations into the next decade. The LANSCE accelerator provides pulsed protons and spallation neutrons for defense and civilian applications. This project involves replacing all the existing 201 MHz RF stations and 805 MHz klystrons. LANSCE is also currently in the conceptual design phase of a program called the Material Test Station (MTS) to establish a 1 MW target station to irradiate fast reactor fuels and materials. A pre conceptual design is also in progress to extend the capabilities of MTS to a 2 MW target that will enable the first in a new generation of scientific facilities for the materials community. The emphasis of this new facility is "Matter-Radiation Interactions in Extremes" (MaRIE) which will be used to discover and design the advanced materials needed to meet 21st century national security and energy security challenges. The design and test results of the new RF systems will be presented as well as the RF system changes required to support the new missions.

MOPS043	Beam Performance in H⁻ Injector of LANSCE	697
	Y.K. Batygin, C. Pillai, L. Rybarcyk LANL, Los Alamos, New Mexico, USA
	During beam development time in 2010 we performed a series of beam emittance and beam profile scans along 750-keV H⁻ beam transport and 800-MeV linac. The purpose of the measurements was to determine the effects of space charge, slow-wave intensity modulation or chopping, RF buncher fields, and vacuum conditions on beam performance. As previously reported, from our observation and analysis we concluded that the 750 keV H⁻ beam transport is space-charge uncompensated. This presentation will look at the relative importance of space-charge, chopping, and RF-buncher on the observed emittance growth for beam in the short and long pulse regime as well as the effects of beam line vacuum degradation on beam size and emittance at the end of the linac. Y. Batygin et al., “Space-charge effects in H⁻ Low-Energy Beam Transport of LANSCE,” to be published in Proc. of the 2011 Particle Accelerator Conference, March 28-April 1, 2011, New York, NY.

WEPS067	An H-Mode Accelerator with PMQ Focusing as a LANSCE DTL Replacement	2655
	S.S. Kurennoy, L. Rybarcyk, T.P. Wangler LANL, Los Alamos, New Mexico, USA
	High-efficiency normal-conducting RF accelerating structures based on H-mode cavities with a transverse beam focusing by permanent-magnet quadrupoles (PMQ) have been developed for beam velocities in the range of a few percent of the speed of light. At these low beam velocities, an inter-digital H-mode (IH-PMQ) linac is an order of magnitude more efficient than a standard drift-tube linac (DTL). At the Los Alamos Neutron Science Center (LANSCE), upgrades of the proton linac front end are currently under consideration. In view of these plans, we explore a further option of replacing the aging LANSCE DTL by an efficient H-PMQ accelerator. Here we assume that a 201.25-MHz RFQ-based front end up to 750 keV (4% of the speed of light) is followed first by IH-PMQ structures and then by cross-bar H-mode cavities with PMQ focusing (CH-PMQ). Such an H-PMQ linac would bring proton and H⁻ beams to the energy of 100 MeV and transfer them into the existing side-coupled-cavity linac (CCL). Results of the combined electromagnetic and beam-dynamics modeling of the proposed H-PMQ accelerator will be presented. S.S. Kurennoy et al., “H-Mode Accelerating Structures with PMQ Beam Focusing,” PRST-AB, 2011 (submitted).

WEPS068	Progress towards an RFQ-based Front End for LANSCE	2658
	R.W. Garnett, S.S. Kurennoy, J.F. O'Hara, L. Rybarcyk LANL, Los Alamos, New Mexico, USA A. Schempp IAP, Frankfurt am Main, Germany
	Funding: This work is supported by the U. S. Department of Energy Contract DE-AC52-06NA25396. The LANSCE linear accelerator at Los Alamos National Laboratory provides H⁻ and H⁺ beams to several user facilities that support Isotope Production, NNSA Stockpile Stewardship, and Basic Energy Science programs. These beams are initially accelerated to 750 keV using Cockcroft-Walton (CW) based injectors that have been in operation for over 37 years. They have failure modes which can result in prolonged operational downtime due to the unavailability of replacement parts. To reduce long-term operational risks and to realize future beam performance goals in support of the Materials Test Station (MTS) and the Matter-Radiation Interactions in Extremes (MaRIE) Facility, plans are underway to develop a Radio-Frequency Quadrupole (RFQ) based front end as a modern injector replacement for the existing CW injectors. Our progress to date will be discussed.

Paper

Title

Page

LANSCE RF System Improvements for Current and Future Programs*

238

D. Rees, J.L. Erickson, R.W. Garnett, J.T.M. Lyles, L. Rybarcyk
LANL, Los Alamos, New Mexico, USA

The Los Alamos Neutron Science Center (LANSCE) is in the midst of an upgrade of the RF systems. This project will return LANSCE to its historical operating capability and sustain facility operations into the next decade. The LANSCE accelerator provides pulsed protons and spallation neutrons for defense and civilian applications. This project involves replacing all the existing 201 MHz RF stations and 805 MHz klystrons. LANSCE is also currently in the conceptual design phase of a program called the Material Test Station (MTS) to establish a 1 MW target station to irradiate fast reactor fuels and materials. A pre conceptual design is also in progress to extend the capabilities of MTS to a 2 MW target that will enable the first in a new generation of scientific facilities for the materials community. The emphasis of this new facility is "Matter-Radiation Interactions in Extremes" (MaRIE) which will be used to discover and design the advanced materials needed to meet 21st century national security and energy security challenges. The design and test results of the new RF systems will be presented as well as the RF system changes required to support the new missions.

MOPS043

Beam Performance in H⁻ Injector of LANSCE

697

Y.K. Batygin, C. Pillai, L. Rybarcyk
LANL, Los Alamos, New Mexico, USA

During beam development time in 2010 we performed a series of beam emittance and beam profile scans along 750-keV H⁻ beam transport and 800-MeV linac. The purpose of the measurements was to determine the effects of space charge, slow-wave intensity modulation or chopping, RF buncher fields, and vacuum conditions on beam performance. As previously reported*, from our observation and analysis we concluded that the 750 keV H⁻ beam transport is space-charge uncompensated. This presentation will look at the relative importance of space-charge, chopping, and RF-buncher on the observed emittance growth for beam in the short and long pulse regime as well as the effects of beam line vacuum degradation on beam size and emittance at the end of the linac.
* Y. Batygin et al., “Space-charge effects in H⁻ Low-Energy Beam Transport of LANSCE,” to be published in Proc. of the 2011 Particle Accelerator Conference, March 28-April 1, 2011, New York, NY.

WEPS067

An H-Mode Accelerator with PMQ Focusing as a LANSCE DTL Replacement

2655

S.S. Kurennoy, L. Rybarcyk, T.P. Wangler
LANL, Los Alamos, New Mexico, USA

High-efficiency normal-conducting RF accelerating structures based on H-mode cavities with a transverse beam focusing by permanent-magnet quadrupoles (PMQ) have been developed for beam velocities in the range of a few percent of the speed of light*. At these low beam velocities, an inter-digital H-mode (IH-PMQ) linac is an order of magnitude more efficient than a standard drift-tube linac (DTL). At the Los Alamos Neutron Science Center (LANSCE), upgrades of the proton linac front end are currently under consideration. In view of these plans, we explore a further option of replacing the aging LANSCE DTL by an efficient H-PMQ accelerator. Here we assume that a 201.25-MHz RFQ-based front end up to 750 keV (4% of the speed of light) is followed first by IH-PMQ structures and then by cross-bar H-mode cavities with PMQ focusing (CH-PMQ). Such an H-PMQ linac would bring proton and H⁻ beams to the energy of 100 MeV and transfer them into the existing side-coupled-cavity linac (CCL). Results of the combined electromagnetic and beam-dynamics modeling of the proposed H-PMQ accelerator will be presented.
* S.S. Kurennoy et al., “H-Mode Accelerating Structures with PMQ Beam Focusing,” PRST-AB, 2011 (submitted).

WEPS068

Progress towards an RFQ-based Front End for LANSCE

2658

R.W. Garnett, S.S. Kurennoy, J.F. O'Hara, L. Rybarcyk
LANL, Los Alamos, New Mexico, USA
A. Schempp
IAP, Frankfurt am Main, Germany

Funding: This work is supported by the U. S. Department of Energy Contract DE-AC52-06NA25396.
The LANSCE linear accelerator at Los Alamos National Laboratory provides H⁻ and H⁺ beams to several user facilities that support Isotope Production, NNSA Stockpile Stewardship, and Basic Energy Science programs. These beams are initially accelerated to 750 keV using Cockcroft-Walton (CW) based injectors that have been in operation for over 37 years. They have failure modes which can result in prolonged operational downtime due to the unavailability of replacement parts. To reduce long-term operational risks and to realize future beam performance goals in support of the Materials Test Station (MTS) and the Matter-Radiation Interactions in Extremes (MaRIE) Facility, plans are underway to develop a Radio-Frequency Quadrupole (RFQ) based front end as a modern injector replacement for the existing CW injectors. Our progress to date will be discussed.