IBIC2013 - List of Authors (Rawnsley, W.R.)

Paper

Title

Page

A Beam Current Monitor for the VECC Accelerator

275

W.R. Rawnsley, R.E. Laxdal
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

TRIUMF is building VECC, the first stage of a 50 MeV electron linac. Beam diagnostic devices will be inserted radially into 8-port vacuum boxes. RF shields, 6.3 cm dia. tubes perforated by pump out slots, can be inserted to reduce wakefields. They will also serve as capacitive probes picking up harmonics of the 650 MHz bunch rate. 100 mV P/P was measured for 3 mA at 100 kV. A SC cavity will accelerate the beam to 10 MeV. The dump current is limited by the shielding to 300 W. We will use a 3 mA beam at 1% duty cycle. Two RF shields will monitor the current. A newly developed circuit will give dc outputs proportional to the peak and average current. It uses a log detector with range of 70 dB for 1 dB of error and a rise and fall time of ~20 ns. Terasic development boards process the log signal. It is digitized by a 14-bit ADC at a 50 MHz rate and passed to a FPGA programmed in Verilog. Altera Megafunctions offset, scale, convert to floating point, antilog and filter the signal in a pipeline architecture. Two 14-bit DACs provide the outputs. Digital processing maintains the wide dynamic range. Beam pulses can be <250 ns and the sample rate insures accuracy at low duty cycle.

Poster MOPF27 [1.314 MB]

TUPC06

Status of Beam Diagnostic Systems for TRIUMF Electron Linac

361

V.A. Verzilov, P.S. Birney, D.P. Cameron, P. Dirksen, J.V. Holek, S.Y. Kajioka, S. Kellogg, M. Lenckowski, M. Minato, W.R. Rawnsley
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
J.M. Abernathy, D. Karlen, D.W. Storey
Victoria University, Victoria, B.C., Canada

TRIUMF laboratory is currently in a phase of the construction of a superconducting 50 MeV 10 mA cw electron LINAC to drive photo-fission based rare radioactive isotope beam (RIB) production. The project imposes certain technical challenges on various accelerator systems including beam diagnostics. In the first place these are a high beam power and strongly varying operating modes ranging from microsecond beam pulses to the cw regime. Diagnostics development interleaves with the construction of the diagnostics instrumentation required for the test facility which delivered the first beam in Fall of 2011. The paper reports the present status of various diagnostics systems along with measurement results obtained at the test facility.

Paper	Title	Page
MOPF27	A Beam Current Monitor for the VECC Accelerator	275
	W.R. Rawnsley, R.E. Laxdal TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	TRIUMF is building VECC, the first stage of a 50 MeV electron linac. Beam diagnostic devices will be inserted radially into 8-port vacuum boxes. RF shields, 6.3 cm dia. tubes perforated by pump out slots, can be inserted to reduce wakefields. They will also serve as capacitive probes picking up harmonics of the 650 MHz bunch rate. 100 mV P/P was measured for 3 mA at 100 kV. A SC cavity will accelerate the beam to 10 MeV. The dump current is limited by the shielding to 300 W. We will use a 3 mA beam at 1% duty cycle. Two RF shields will monitor the current. A newly developed circuit will give dc outputs proportional to the peak and average current. It uses a log detector with range of 70 dB for 1 dB of error and a rise and fall time of ~20 ns. Terasic development boards process the log signal. It is digitized by a 14-bit ADC at a 50 MHz rate and passed to a FPGA programmed in Verilog. Altera Megafunctions offset, scale, convert to floating point, antilog and filter the signal in a pipeline architecture. Two 14-bit DACs provide the outputs. Digital processing maintains the wide dynamic range. Beam pulses can be <250 ns and the sample rate insures accuracy at low duty cycle.
	Poster MOPF27 [1.314 MB]

TUPC06	Status of Beam Diagnostic Systems for TRIUMF Electron Linac	361
	V.A. Verzilov, P.S. Birney, D.P. Cameron, P. Dirksen, J.V. Holek, S.Y. Kajioka, S. Kellogg, M. Lenckowski, M. Minato, W.R. Rawnsley TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada J.M. Abernathy, D. Karlen, D.W. Storey Victoria University, Victoria, B.C., Canada
	TRIUMF laboratory is currently in a phase of the construction of a superconducting 50 MeV 10 mA cw electron LINAC to drive photo-fission based rare radioactive isotope beam (RIB) production. The project imposes certain technical challenges on various accelerator systems including beam diagnostics. In the first place these are a high beam power and strongly varying operating modes ranging from microsecond beam pulses to the cw regime. Diagnostics development interleaves with the construction of the diagnostics instrumentation required for the test facility which delivered the first beam in Fall of 2011. The paper reports the present status of various diagnostics systems along with measurement results obtained at the test facility.