Author: Hadmack, M.R.
Paper Title Page
MOPWA069 Time-resolved Electron Beam Position Monitor Macropulse Waveform Measurement in MkV Linear Accelerator at University of Hawaii Free Electron Laser Laboratory 837
  • P. Niknejadi, M.R. Hadmack, B.T. Jacobson, J. Madey, G.S. Varner
    University of Hawaii, Honolulu, HI, USA
  Real time waveform measurements of electron beams will provide valuable data and possibility of online bunch diagnostics in linear accelerators. The University of Hawaii Linear Accelerator utilizes a thermionic LaB6 cathode microwave gun injector and a single section of S-band linear accelerator capable of producing a 40MeV, 1-2 ps bunched electron beam with average current of 200mA over the duration of a 4.5 us macropulse. This beam, pulsed at 4 Hz, produces strong RF signal at 2.856 GHz which is coupled out of the beam-pipe by a family of stripline beam position monitors (BPM's) and read out using custom built logarithmic-difference based electronics installed in 2012.* A high speed Analog to Digital Convertor and Field-Programmable Gate Array will be used to digitize the signal and record the waveform. The goal is to make a cost effective oscilloscope on a chip/board with feasible and functional operation to achieve optimal beam configuration. The circuit board design, in-circuit programming, waveform digitization challenges, and preliminary results from the prototype will be presented at the conference.
* B. T. Jacobson, M. R. Hadmack, J. M. J. Madey, P. Niknejadi "Modular Logarithmic Amplifier Beam Position Monitor Readout System at University of Hawai’i," IBIC Conf. Proc. (2012)