Tuning of LANSCE 805-MHz high-energy linear accelerator with reduced beam losses

Batygin, Y. K.; Shelley, F. E.; Watkins, H. A.

doi:10.1016/j.nima.2018.11.103

Title: Tuning of LANSCE 805-MHz high-energy linear accelerator with reduced beam losses

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Abstract

Suppression of beam losses is essential for successful operation of high-intensity linac. Historically, the values of the field amplitudes and phases of the side-coupled, 805-MHz LANSCE linac modules are maintained using a well-known delta-t tuning procedure. Transverse matching of the beam with accelerator is performed through adjustments of beam ellipses in 4D phase space with accelerator lattice using matching quadrupoles. Control of the beam-energy ramp along the length of a proton linear accelerator is required to improve tune of accelerator and decrease beam losses. Time-of-flight measurements of the H^- beam energy are now being used to confirm and improve the overall control of the energy ramp along the linac. The time-of-flight method utilizes absolute measurements of beam energy using direct signals from beam at an oscilloscope, as well as the difference in RF phases measured as the beam passes installed delta-t pickup loops. A newly developed BPPM data acquisition system is used. Beam energy measurement along accelerator together with phase scans, klystrons output power control, and delta-t method, allow tuning of accelerator much more close to original design and reduce losses generated by linac. Details of the upgraded tuning procedure and results of tuning and operation are presented here.

Authors:

Batygin, Y. K. ^[1]; Shelley, F. E. ^[1]; Watkins, H. A. ^[1]

Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

Publication Date:: Wed Nov 28 00:00:00 EST 2018

Research Org.:: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)

Sponsoring Org.:: USDOE

OSTI Identifier:: 1542841

Alternate Identifier(s):: OSTI ID: 1636244

Report Number(s):: LA-UR-18-26790
Journal ID: ISSN 0168-9002

Grant/Contract Number:: 89233218CNA000001; AC52-06NA25396

Resource Type:: Accepted Manuscript

Journal Name:: Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment

Additional Journal Information:: Journal Volume: 916; Journal ID: ISSN 0168-9002

Publisher:: Elsevier

Country of Publication:: United States

Language:: English

Subject:: 46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY

Citation Formats


                    Batygin, Y. K., Shelley, F. E., and Watkins, H. A. Tuning of LANSCE 805-MHz high-energy linear accelerator with reduced beam losses.  United States: N. p., 2018. 
Web.  doi:10.1016/j.nima.2018.11.103.

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                    Batygin, Y. K., Shelley, F. E., & Watkins, H. A. Tuning of LANSCE 805-MHz high-energy linear accelerator with reduced beam losses.  United States.  https://doi.org/10.1016/j.nima.2018.11.103

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                    Batygin, Y. K., Shelley, F. E., and Watkins, H. A. Wed .  
"Tuning of LANSCE 805-MHz high-energy linear accelerator with reduced beam losses".  United States.  https://doi.org/10.1016/j.nima.2018.11.103.  https://www.osti.gov/servlets/purl/1542841.

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@article{osti_1542841,

  title        = {Tuning of LANSCE 805-MHz high-energy linear accelerator with reduced beam losses},

  author       = {Batygin, Y. K. and Shelley, F. E. and Watkins, H. A.},

  abstractNote = {Suppression of beam losses is essential for successful operation of high-intensity linac. Historically, the values of the field amplitudes and phases of the side-coupled, 805-MHz LANSCE linac modules are maintained using a well-known delta-t tuning procedure. Transverse matching of the beam with accelerator is performed through adjustments of beam ellipses in 4D phase space with accelerator lattice using matching quadrupoles. Control of the beam-energy ramp along the length of a proton linear accelerator is required to improve tune of accelerator and decrease beam losses. Time-of-flight measurements of the H- beam energy are now being used to confirm and improve the overall control of the energy ramp along the linac. The time-of-flight method utilizes absolute measurements of beam energy using direct signals from beam at an oscilloscope, as well as the difference in RF phases measured as the beam passes installed delta-t pickup loops. A newly developed BPPM data acquisition system is used. Beam energy measurement along accelerator together with phase scans, klystrons output power control, and delta-t method, allow tuning of accelerator much more close to original design and reduce losses generated by linac. Details of the upgraded tuning procedure and results of tuning and operation are presented here.},

  doi          = {10.1016/j.nima.2018.11.103},

  journal      = {Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment},

  number       = ,

  volume       = 916,

  place        = {United States},

  year         = {Wed Nov 28 00:00:00 EST 2018},

  month        = {Wed Nov 28 00:00:00 EST 2018}

}

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