TUP2WE —  WG-E   (19-Jun-18   16:00—18:00)
Chair: M.G. Minty, BNL, Upton, Long Island, New York, USA
Paper Title Page
TUP2WE01 Injection Foil Temperature Measurements at the SNS Accelerator -1
  • W. Blokland, C.F. Luck, A. Rakhman
    ORNL, Oak Ridge, Tennessee, USA
  • N.J. Evans
    ORNL RAD, Oak Ridge, Tennessee, USA
  Funding: This manuscript has been authored by UT-Battelle, LLC, under Contract No. DE-AC0500OR22725 with the U.S. Department of Energy.
The SNS uses charge exchange injection to minimize losses during the accumulation of the accelerated beam in the ring. A stripper foil implements this by removing the electrons from the high intensity H beam coming from the linac. At a beam power of 1.2 MW, the foil lasts for many weeks, sometimes months. However, given the upgrade to 2.8 MW, it is important to know the current temperature of stripper foil in order to estimate its lifetime for the new beam power and beam size. In this paper, we discuss several methods to measure the temperature of stripper foil exposed to current operating conditions of the SNS accelerator. Given the high radiation in the vicinity of the foil, the uncertainty in the foil's emissivity, and available resources, we chose a two-wavelength pyrometer that is located 40 m from the foil. The pyrometer is composed of two mirrors, a refracting telescope, and two photodiodes. We present the calibration data and the temporally resolved measurements made with this pyrometer.
slides icon Slides TUP2WE01 [13.195 MB]  
TUP2WE02 The Beam Conditions on the Target and its Operational Impacts on Beam Intercepting Devices at European Spallation Source -1
  • Y. Lee, R. Miyamoto, T.J. Shea
    ESS, Lund, Sweden
  • H.D. Thomsen
    ISA, Aarhus, Denmark
  A large flux of spallation neutrons will be produced at the European Spallation Source (ESS) by impinging high power proton beam on the tungsten target. Until the 5 MW proton beam is stopped by the spallation target, it travels through a number of beam intercepting devices (BIDs), which include the proton beam window, a multi-wire beam profile monitor, an aperture monitor, the beam entrance window, spallation material and the target shroud. The beam-induced thermo-mechanical loads and the damage dose rate in the BIDs are largely determined by the beam energy and the beam current density. At ESS, the proton beam energy will be commissioned step-wisely, from 570 MeV towards 2 GeV. The beam current density on the BIDs in the target station is equally painted by raster beam optics. The ESS Linac and its beam optics will create rectangular beam profiles on the target with varying beam intensities. In this paper, we study the impacts of different plausible beam intensities and beam energies on the thermo-mechanical loads and radiation damage rates in the BIDs at the ESS target station.  
slides icon Slides TUP2WE02 [9.826 MB]  
TUP2WE03 Radiation Damage Calculation in PHITS and Benchmarking Experiment for Cryogenic-Sample High-Energy Proton Irradiation -1
  • Y. Iwamoto, D. Satoh
    JAEA, Ibaraki-ken, Japan
  • Y. Ishi, Y. Kuriyama, T. Uesugi, H. Yashima, T. Yoshiie
    Kyoto University, Research Reactor Institute, Osaka, Japan
  • H. Matsuda, S.I. Meigo
    JAEA/J-PARC, Tokai-mura, Japan
  • T. Nakamoto
    KEK, Ibaraki, Japan
  • K. Niita
    Research Organization for Information Science & Technology, Ibaraki, Japan
  • R.M. Ronningen
    FRIB, East Lansing, Michigan, USA
  • T. Shima
    RCNP, Osaka, Japan
  Funding: The experimental study was supported by JSPS KAKENHI, Grant Number JP 16H04638 and 25820450. The calculation work was supported in part by the US National Science Foundation under grant PHY06-06007.
The radiation damage model in the Particle and Heavy Ion Transport code System (PHITS) has been developed using the screened Coulomb scattering to evaluate the energy of the target Primary Knock on Atom (PKA) created by the projectile and the secondary particles which include all particles created from the sequential nuclear reactions. For the high-energy proton incident reactions, a target PKA created by the secondary particles was more dominant than a target PKA created by the projectile. To validate prediction of DPA values in metals irradiated by >100 MeV protons, we developed a proton irradiation device with a Gifford-McMahon (GM) cryocooler to cryogenically cool wire samples. By using this device, the defect-induced electrical resistivity changes related to the DPA cross section of copper and aluminum were measured under irradiation with 125 and 200 MeV protons at cryogenic temperature. A comparison of the experimental DPA cross sections with the calculated results indicates that the athermal-recombination-corrected displacement damage (arc-dpa) provide better quantitative descriptions of the DPA cross section than NRT-dpa without defect production efficiencies.
slides icon Slides TUP2WE03 [4.747 MB]  
TUP2WE04 Design of the Target Dump Injection Segmented (TDIS) in the Framework of the High Luminosity Large Hadron Collider (HL-LHC) Project -1
  • L. Teofili, D. Carbajo Perez, I. Lamas Garcia, M. Migliorati, A. Perillo
    CERN, Geneva, Switzerland
  • M. Migliorati
    INFN-Roma1, Rome, Italy
  • M. Migliorati
    Sapienza University of Rome, Rome, Italy
  The High Luminosity Large Hadron Collider (HL-LHC) Project at CERN calls for increasing beam brightness and intensity. In this scenario most equipment has to be redesigned and rebuilt. In particular, beam intercepting devices (as dumps, collimators, absorbers and scrapers) have to withstand impact or scraping of the new intense HL-LHC beams without failures. Further, minimizing the electromagnetic beam-device interactions is also a key design driver since they can lead to beam instabilities and excessive thermo-mechanical loading of devices. In this context, the present study assesses the conceptual design quality of the new LHC injection dump, the Target Dump Injection Segmented (TDIS), from an electromagnetic and thermo-mechanical perspective. This contribution analyzes the thermo-mechanical response of the device considering two cases: an accidental beam impact scenario and another accidental scenario with complete failure of the RF-contacts. Further, this paper presents the preliminary results for the simulation of the energy deposited by the two counter-rotating beams circulating in the device.  
slides icon Slides TUP2WE04 [10.895 MB]