Author: Shemyakin, A.V.
Paper Title Page
MOPLO19 Test Results of PIP2IT MEBT Vacuum Protection System 278
 
  • A.Z. Chen, R. Andrews, C.M. Baffes, D.D. Lambert, L.R. Prost, A.V. Shemyakin, T.J. Zuchnik
    Fermilab, Batavia, Illinois, USA
 
  Funding: This manuscript has been authored by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, Office of Science, Office of High Energy Physics
The central part of PIP-II program of upgrades proposed for the Fermilab injection complex is an 800 MeV, 2 mA, CW-compatible SRF linac. Acceleration in superconducting cavities begins from a low energy of 2.1 MeV, so that the first cryomodule, Half Wave Resonator (HWR) borders the warm Medium Beam Transport (MEBT) line. To minimize the amount of gas that may enter the SRF linac in a case if a vacuum failure occurs in the warm front end, a vacuum protection system is envisioned to be used in the PIP-II MEBT. It features a fast closing valve with two sensors and a differential pumping insert. The system prototype is installed in the PIP-II Injector Test (PIP2IT) accelerator and recently is successfully tested in several modes modelling the vacuum failures. The report presents the design of the vacuum protection system and results of its tests.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-MOPLO19  
About • paper received ※ 28 August 2019       paper accepted ※ 03 September 2019       issue date ※ 08 October 2019  
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TUPLS08 Analysis of Allison Scanner Phase Portraits Using Action-Phase Coordinates 467
SUPLO06   use link to see paper's listing under its alternate paper code  
 
  • C.J. Richard
    NSCL, East Lansing, Michigan, USA
  • J.-P. Carneiro, L.R. Prost, A.V. Shemyakin
    Fermilab, Batavia, Illinois, USA
 
  Allison scanners provide detailed information on the beam transverse phase space. An effective way for analyzing the beam distribution from these measurements is to use action-phase coordinates, where beam propagation in a linear lattice is reduced to advancing the phase. This report presents such analysis for measurements performed with a 2.1 MeV, 5 mA H beam in the MEBT of the PIP2IT test accelerator at Fermilab. In part, with the choice of calculating the Twiss parameters over the high intensity portion of the beam, the beam core is found to be phase-independent with intensity decreasing exponentially with action, while the beam tails exhibit a clear phase dependence that is stable over the beam line.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-TUPLS08  
About • paper received ※ 27 August 2019       paper accepted ※ 05 September 2019       issue date ※ 08 October 2019  
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WEPLM02 Finding Beam Loss Locations in a Linac with Oscillating Dipole Correctors 663
 
  • A.V. Shemyakin, K. Seiya
    Fermilab, Batavia, Illinois, USA
  • R. Prakash
    RRCAT, Indore, India
 
  Funding: This manuscript has been authored by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, Office of Science, Office of High Energy Physics
The paper proposes a method of finding the beam loss locations in a linac. If the beam is scraped at an aperture limitation, moving its centroid with two dipole correctors located upstream and oscillating in sync produces a line at the corresponding frequency in spectra of current-sensitive devices downstream of the loss point. The phase of this signal contains information about the location of the beam loss. Similar lines appear also in the position signals of Beam Position Monitors (BPMs). The phases of the BPM position lines change monotonically (within each 2π) along the linac and can be used a reference system. The phase of the loss signal compared with this reference system pinpoints the beam loss location, assuming that longitudinal coordinates of the BPMs are known. If the correctors deflection amplitudes and the phase offset between their waveforms are chosen optimally and well calibrated, the same measurement provides values of the β-function and the betatron phase advance at the BPM locations. Optics measurements of this type can be made parasitically, with negligible effect on the emittance, if a long measurement time is acceptable.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEPLM02  
About • paper received ※ 27 August 2019       paper accepted ※ 19 November 2019       issue date ※ 08 October 2019  
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WEPLH02 Experience with Long-Pulse Operation of the PIP2IT Warm Front End 803
 
  • A.V. Shemyakin, J.-P. Carneiro, A.Z. Chen, D. Frolov, B.M. Hanna, R. Neswold, L.R. Prost, G.W. Saewert, A. Saini, V.E. Scarpine, A. Warner, J.Y. Wu
    Fermilab, Batavia, Illinois, USA
  • C.J. Richard
    NSCL, East Lansing, Michigan, USA
 
  Funding: This manuscript has been authored by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, Office of Science, Office of High Energy Physics
The warm front end of the PIP2IT accelerator, assembled and commissioned at Fermilab, consists of a 15 mA DC, 30 keV H ion source, a 2-m long Low Energy Beam Transport (LEBT) line, a 2.1-MeV, 162.5 MHz CW RFQ, followed by a 10-m long Medium Energy Beam Transport (MEBT) line. A part of the commissioning efforts involves operation in regimes where the average beam power in this front end emulates the operation of the proposed PIP-II accelerator, which will have a duty factor of 1.1% or above. The maximum achieved power is 5 kW (2.1 MeV x 5 mA x 25 ms x 20 Hz). This paper describes the difficulties encountered and some of the solutions that were implemented.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEPLH02  
About • paper received ※ 20 August 2019       paper accepted ※ 01 September 2019       issue date ※ 08 October 2019  
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