Author: Bertsche, W.
Paper Title Page
TUBO04 Measuring the Beam Profile by Counting Ionization Electrons 252
 
  • H.S. Sandberg, W. Bertsche
    UMAN, Manchester, United Kingdom
  • D. Bodart, B. Dehning, S. Levasseur, H.S. Sandberg, G. Schneider, J.W. Storey, R. Veness
    CERN, Geneva, Switzerland
  • S.M. Gibson
    Royal Holloway, University of London, Surrey, United Kingdom
  • K. Satou
    J-PARC, KEK & JAEA, Ibaraki-ken, Japan
 
  The principle of non-destructive beam profile measurement with rest gas ionization electrons has remained largely unchanged since the technique was first proposed in the late 1960’s. Ionization electrons (or ions) are transported by an electrostatic field onto an imaging detector, where the spatial distribution of detected electrons is a direct measure of the transverse beam profile. The detector typically consists of one or more Micro-Channel Plates (MCP’s) to amplify the signal, followed by either a phosphor screen and camera, or pickup electrodes. A long-standing problem is the ageing of the MCP’s, which limits the accuracy of the beam profile measurement. A new technique to detect ionization electrons has been developed at CERN, which uses a hybrid pixel detector to detect single ionisation electrons. This allows the application of counting statistics to the beam profile measurement. It will be shown that a meaningful beam profile can be extracted from only 100 electrons. Results from the new instrument will be presented, which demonstrate the ability to measure the beam profile of single bunches turn-by-turn, which offers new opportunities for beam diagnostic insights.  
slides icon Slides TUBO04 [2.199 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-TUBO04  
About • paper received ※ 03 September 2019       paper accepted ※ 08 September 2019       issue date ※ 10 November 2019  
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WEPP040 Optimization of Antiproton Capture for Antihydrogen Creation in the ALPHA Experiment 633
 
  • S.S. Fabbri, W. Bertsche
    UMAN, Manchester, United Kingdom
 
  At the ALPHA Experiment at CERN, thin foils of material are used to slow down and trap antiprotons in a Penning trap, where they can be used for antihydrogen creation and measurements. Historically, over 99% of antiprotons are lost during the capture process as a result of the 5.3 MeV initial kinetic energy of the beam delivered by the Antiproton Decelerator. This places a limit early on in the achievable number of antihydrogen. ELENA is a new storage ring coming online which will lower this initial kinetic energy of the beam to 100 keV, requiring experiments to update their infrastructure. We present Monte Carlo and particle tracking simulation results for the optimization of the new degrading foil material, thickness, and location in the ALPHA catching Penning trap. From these results, we expect an upper capture efficiency of roughly 50 %. We further propose techniques for manipulating, detecting and extracting on the anticipated larger-numbered antiproton plasmas. These methods and associated hardware developments will allow performing antiproton experiments with significantly higher efficiency in ALPHA and other similar antiproton-based experiments.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-WEPP040  
About • paper received ※ 04 September 2019       paper accepted ※ 11 September 2019       issue date ※ 10 November 2019  
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