Author: Seimiya, Y.
Paper Title Page
TUPP019 Experimental Tests of Screen Materials for High-Precision Transverse Beam-Size Measurements at the SuperKEKB Injector Linac 335
 
  • F. Miyahara, K. Furukawa, M. Satoh, Y. Seimiya, T. Suwada
    KEK, Ibaraki, Japan
 
  The SuperKEKB injector linac is required to deliver low-emittance electron and positron beams. Wire scanners are employed to measure Twiss parameters and to adjust beam optics conditions. Screen monitors also play important roles for single-shot measurements. However, the beam size became more than 10-times smaller compared with that of the KEKB injection. Beam tests have been performed in order to evaluate materials for high-precision transverse beam-size measurements at the injector. The main purpose of the beam tests is to quantitatively investigate the saturation effect of each screen material for generating the scintillation light, which is strongly depending on the beam-charge density. Several scintillating screen materials including YAG:Ce, LYSO:Ce, BGO and aluminum ceramic have been tested with high energy and high charge-density electron beams. The results are compared with that obtained by the OTR measurement. The saturation of the luminescence was confirmed for all crystals and evaluated in the charge density of 0.5-1.5 nC/mm2. The cause of the saturation and the effect to the measurement are discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-TUPP019  
About • paper received ※ 07 September 2019       paper accepted ※ 10 September 2019       issue date ※ 10 November 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEPP006 Operational Performance of New Detection Electronics for Stripline-Type Beam Position Monitors at the SuperKEKB Injector Linac 514
 
  • F. Miyahara, K. Furukawa, M. Satoh, Y. Seimiya, T. Suwada
    KEK, Ibaraki, Japan
 
  SuperKEKB injector linac delivers four different beam modes modulated pulse by pulse at 50 Hz, which have 100-times different beam charges, and a pulse may contain two bunches only 96-ns apart. Required low-emittance beams for SuperKEKB rings would need precise beam orbit controls in order to suppress the transverse wakefield in the accelerating structures. A new detection electronics with a wide dynamic range of 40 dB with a high resolution based on a 180-MHz narrow-band detection technique for stripline-type beam position monitors (BPMs) has been developed for the SuperKEKB injector linac. While such measurement condition is challenging, a position resolution of 3 micrometer in one standard deviation was successfully achieved with beam-based tests. The self-calibration system is also installed in order to compensate gain drifts for each input channel with an accuracy down to 0.1%, by using test pulses going through stripline heads between 50-Hz beam pulses. The design concept of the new detection electronics is described in detail, as well as operational performance of synchronized measurement with 100 BPMs for injection beams to four electron/positron storage rings.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IBIC2019-WEPP006  
About • paper received ※ 09 September 2019       paper accepted ※ 11 September 2019       issue date ※ 10 November 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)