NAPAC2019 - List of Authors (Rybarcyk, L.)

Paper	Title	Page
MOPLO18	Thermal Analysis of the LANSCE H⁺ RFQ Test Stand Faraday Cup	274
	E.N. Pulliam, I. Draganić, J.L. Medina, J.P. Montross, J.F. O’Hara, L. Rybarcyk LANL, Los Alamos, New Mexico, USA
	The Los Alamos Neutron Science Center (LANSCE) op-erates one of the nation’s most powerful linear accelera-tors (LINAC). Currently the facility utilizes two 750 keV Cockcroft-Walton (CW) based injectors for transporting H⁺ and H⁻ beams into the 800 MeV accelerator. A Radio Frequency Quadrupole (RFQ) design is being proposed to replace the aged CW injectors. An important component of the RFQ Test Stand is the Faraday cup that is assem-bled at the end of the Low Energy Beam Transport (Phase 1 LEBT) and Medium Energy Beam Transport (Phase 3 MEBT). The Faraday cup functions simultaneously as both a beam diagnostic and as a beam stop for each of the three project phases. This paper describes various aspects of the design and analysis of the Faraday cup. The first analysis examined the press fit assembly of the graphite cone and the copper cup components. A finite element analysis (FEA) evaluated the thermal expansion proper-ties of the copper component, and the resulting material stress from the assembly. Second, the beam deposition and heat transfer capability were analyzed for LEBT and MEBT beam power levels. Details of the calculations and analysis will be presented.
	Poster MOPLO18 [3.399 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-MOPLO18
About •	paper received ※ 27 August 2019 paper accepted ※ 25 November 2019 issue date ※ 08 October 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPLH20	Modeling of H⁻ Ion Source at LANSCE	848
	N.A. Yampolsky, I. Draganić, L. Rybarcyk LANL, Los Alamos, New Mexico, USA
	Funding: Work supported by the US Department of Energy under Contract Number DE-AC52-06NA25396 We report on the progress in modeling performance of the H⁻ ion source at LANSCE. The key aspect we address is the lifetime of the tungsten filament. The lifetime depends on multiple parameters of the ion source and can dramatically vary in different regimes of operation. We use the multiphysics approach to model the performance of the ion source. The detailed analysis has been made to recognize key physical processes, which affect the degradation of the filament. The analysis resulted in the analytical model, which includes relevant processes from the first principles. The numerical code based on this model has been developed and benchmarked. The results of the modeling show good agreement with experimental data. As a result, the developed model allows predicting the performance of the ion source in various regimes of operation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEPLH20
About •	paper received ※ 28 August 2019 paper accepted ※ 05 September 2019 issue date ※ 08 October 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Thermal Analysis of the LANSCE H⁺ RFQ Test Stand Faraday Cup

274

E.N. Pulliam, I. Draganić, J.L. Medina, J.P. Montross, J.F. O’Hara, L. Rybarcyk
LANL, Los Alamos, New Mexico, USA

The Los Alamos Neutron Science Center (LANSCE) op-erates one of the nation’s most powerful linear accelera-tors (LINAC). Currently the facility utilizes two 750 keV Cockcroft-Walton (CW) based injectors for transporting H⁺ and H⁻ beams into the 800 MeV accelerator. A Radio Frequency Quadrupole (RFQ) design is being proposed to replace the aged CW injectors. An important component of the RFQ Test Stand is the Faraday cup that is assem-bled at the end of the Low Energy Beam Transport (Phase 1 LEBT) and Medium Energy Beam Transport (Phase 3 MEBT). The Faraday cup functions simultaneously as both a beam diagnostic and as a beam stop for each of the three project phases. This paper describes various aspects of the design and analysis of the Faraday cup. The first analysis examined the press fit assembly of the graphite cone and the copper cup components. A finite element analysis (FEA) evaluated the thermal expansion proper-ties of the copper component, and the resulting material stress from the assembly. Second, the beam deposition and heat transfer capability were analyzed for LEBT and MEBT beam power levels. Details of the calculations and analysis will be presented.

Poster MOPLO18 [3.399 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-MOPLO18

About •

paper received ※ 27 August 2019 paper accepted ※ 25 November 2019 issue date ※ 08 October 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPLH20

Modeling of H⁻ Ion Source at LANSCE

848

N.A. Yampolsky, I. Draganić, L. Rybarcyk
LANL, Los Alamos, New Mexico, USA

Funding: Work supported by the US Department of Energy under Contract Number DE-AC52-06NA25396
We report on the progress in modeling performance of the H⁻ ion source at LANSCE. The key aspect we address is the lifetime of the tungsten filament. The lifetime depends on multiple parameters of the ion source and can dramatically vary in different regimes of operation. We use the multiphysics approach to model the performance of the ion source. The detailed analysis has been made to recognize key physical processes, which affect the degradation of the filament. The analysis resulted in the analytical model, which includes relevant processes from the first principles. The numerical code based on this model has been developed and benchmarked. The results of the modeling show good agreement with experimental data. As a result, the developed model allows predicting the performance of the ion source in various regimes of operation.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEPLH20

About •

paper received ※ 28 August 2019 paper accepted ※ 05 September 2019 issue date ※ 08 October 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)