Author: Hassanzadegan, H.
Paper Title Page
TUPC01 Overview of the European Spallation Source Warm Linac Beam Instrumentation 346
  • B. Cheymol, C. Böhme, I. Dolenc Kittelmann, H. Hassanzadegan, A. Jansson, T.J. Shea, L. Tchelidze
    ESS, Lund, Sweden
  The normal conducting front end of the European Spallation source will accelerate the beam coming for the ion source up to 90 MeV. The ESS front end will consist in an ion source, a low energy beam transport line, a radio frequency quadrupole, a medium energy beam transport line and a drift tube linac. The warm linac will be equipped with beam diagnostics to measure the beam position, the transverse and longitudinal profile as well as beam current and beam losses. This will provide efficient operation of ESS, and ensure keeping the losses at a low level. This paper gives an overview of the beam diagnostics design and their main features.  
TUPC02 Proton Beam Measurement Strategy for the 5 MW European Spallation Source Target 349
  • T.J. Shea, C. Böhme, B. Cheymol, H. Hassanzadegan, E.J. Pitcher
    ESS, Lund, Sweden
  • S.D. Gallimore
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
  • H.D. Thomsen
    ISA, Aarhus, Denmark
  Approaching construction phase in Lund, Sweden, the European Spallation Source (ESS) consists of a superconducting linear accelerator that delivers a 2 GeV, 5 MW proton beam to a rotating tungsten target. As a long pulse neutron source, the ESS does not require an accumulator ring, so the 2.86 ms pulses, with repetition rate of 14 Hz arrive directly from the linear accelerator with low emittance. To avoid damage to target station components, this intense beam must be actively expanded by quadrupoles that produce a centimetre size beamlet, combined with a fast rastering system that paints the beamlet into a 160 mm by 60 mm footprint. Upstream of and within the target station, a suite of devices will measure the beam's density, halo, position, current, and time-of-arrival. Online density measurements are particularly important for machine protection, but present significant challenges. Diverse techniques will provide this measurement within the target station, based upon secondary emission grids, ionisation monitors, luminescent coatings, and Helium gas luminescence. Requirements, system descriptions, and performance estimates will be presented.  
TUPC13 System Overview and Design Considerations of the BPM System of the ESS Linac 388
  • H. Hassanzadegan, A. Jansson, R. Zeng
    ESS, Lund, Sweden
  • A.J. Johansson
    Lund University, Lund, Sweden
  • K. Strniša
    Cosylab, Ljubljana, Slovenia
  • A. Young
    SLAC, Menlo Park, California, USA
  The ESS Linac will include in total more than 140 Beam Position Monitors of different sizes and types. The BPM system needs to measure the beam position, phase and intensity in all foreseen beam modes with a pulse rate of 14 Hz, duration of 2.86 ms and amplitude ranging form 5 mA to 62.5 mA. With respect to the BPM connection to the Machine Interlock System, the total response time must be less than 10 us. The signal level variations from one BPM to another along the Linac should be as small as possible to meet the requirements on the analog gain of the front-end electronics and the dynamic range of the digitizer card input. The other requirement is that the BPM system needs to give at least a rough estimation of the beam position and phase, even if the beam is significantly debouched, ex. during the Linac tuning phase. These requirements and their impact on the design of the BPM detector, the analog front-end electronics and the selection of the digitizer card are discussed in this paper along with a general description of the BPM system.  
poster icon Poster TUPC13 [3.050 MB]  
WEPC06 Beam Instrumentation in the ESS Cold Linac 667
  • C. Böhme, B. Cheymol, I. Dolenc Kittelmann, H. Hassanzadegan, A. Jansson
    ESS, Lund, Sweden
  Parts of the linac of the European Spallation Source will consist of cryogenic cavity modules. In between these will be warm sections at room temperature to host amongst others the beam instrumentation. Each of the warm sections will host two beam position monitors and one or two other instruments, which might be a beam current monitor, invasive and non-invasive transverse beam profile monitor, bunch shape monitor, or halo monitor. The concept of the warm section layout will be shown and the planned instrumentation will be presented.  
WEPC45 Beam Loss Monitoring at the European Spallation Source 795
  • L. Tchelidze, H. Hassanzadegan, A. Jansson, M. Jarosz
    ESS, Lund, Sweden
  At the European Spallation Source proton linear accelerator will generate 5 MW protons to be delivered to a target. This high power accelerator will require significant amount of beam instrumentation, among which the beam loss monitoring system is one of the most important for operation. An LHC type ionization chamber will be used with ~54 uC/Gy sensitivity. At most 1.5 mGy/sec radiation levels are expected close to the beam pipe during normal operation, resulting in up to 80 nA current signal in detectors. Loss monitor electronics is designed to be able to measure currents as little as 1% of the expected current up to as much as 1% of the total beam loss, thus ~800 pA – few mA. In order to study beam loss pattern along the accelerator a coherent model of the whole machine is created for the purposes of Monte Carlo particle transport simulations. Data obtained using the model will be stored in a database together with the initial beam loss conditions. The contents of the database will then be processed using custom neural network algorithms to optimize number and position of the loss monitors and to provide reference on the beam loss localization during operation of the machine.  
poster icon Poster WEPC45 [1.784 MB]  
WEPF30 System Overview and Preliminary Test Results of the ESS Beam Current Monitor System 891
  • H. Hassanzadegan, A. Jansson
    ESS, Lund, Sweden
  • K. Strniša
    Cosylab, Ljubljana, Slovenia
  The ESS Linac will include in total 21 Beam Current Monitors, mostly of ACCT type, to measure the average current over the 2.86 ms beam pulse, the pulse charge and the pulse profile. It is also planned to use a few Fast Current Transformers to check the performance of the fast beam choppers with a rise time as short as 10 ns. In addition to the absolute current measurement, the BCM system needs to measure the differential beam current and act on the Machine Interlock System if the difference exceeds some thresholds. The differential current measurement is particularly important in the low energy part of the Linac, where Beam Loss Monitors cannot reliably detect beam losses. This paper gives an overview of the ESS BCM system and presents some preliminary test results with a commercial ACCT and MTCA.4 electronics.  
poster icon Poster WEPF30 [6.267 MB]