IBIC2013 - List of Keywords (gun)

Paper	Title	Other Keywords	Page
MOAL4	First Results from the Bunch Arrival-Time Monitor at the SwissFEL Test Injector	pick-up, laser, feedback, electron	8
	V.R. Arsov, M.M. Dehler, S. Hunziker, M.G. Kaiser, V. Schlott PSI, Villigen PSI, Switzerland
	Non-destructive electron bunch arrival-time monitors (BAMs) with resolution <10 fs, sensitivity down to 10 pC and high intrinsic bandwidth for double bunch detection are required for reliable operation of SwissFEL. To achieve this ultimate goal, such a monitor based on a Mach-Zehnder electro-optical intensity modulator has been under development at the SwissFEL Test Injector. The high timing precision is derived by a stable pulsed optical reference system. The first BAM is located before the bunch compressor where the bunch energy is 230 MeV and the pulse length is approximately 3 ps. At this position, the bunch arrival time is sensitive to the laser- and gun timing. In this paper, we report on the commissioning of the RF- and optical front ends, the first arrival-time jitter and drift measurements with the entire system, as well as correlation of the arrival-time with different machine and environmental parameters. We achieve a resolution of 20 fs down to 60 pC.
	Slides MOAL4 [1.228 MB]

MOPF27	A Beam Current Monitor for the VECC Accelerator	linac, diagnostics, vacuum, radiation	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]

TUPC03	Commissioning and Diagnostics Development for the New Short-Pulse Injector Laser at FLASH	laser, emittance, electron, SASE	353
	T. Plath, J. Rönsch-Schulenburg, J. Roßbach Uni HH, Hamburg, Germany H. Schlarb, S. Schreiber, B. Steffen DESY, Hamburg, Germany
	In order to extend the parameter range of FLASH towards shorter electron pulses down to a few fs SASE pulses, shorter bunches with very small charges of a few tens of picocoulombs are necessary directly at the photo injector. Therefore a new injector laser delivering pulses of 1 to 5 ps has been installed and commissioned. The influence of the laser parameters on the electron beam was studied theoretically. In this paper we discuss the required laser beam diagnostics and present measurements of critical laser and electron beam parameters.
	Poster TUPC03 [1.076 MB]

TUPC05	Laser and Photocathode Gun Instrumentation for the ASTA Accelerator Test Stand at SLAC	laser, cathode, LCLS, SLAC	357
	J. Sheppard, W.J. Corbett, S. Gilevich, E.N. Jongewaard, J.R. Lewandowski, P. Stefan, T. Vecchione, S.P. Weathersby, F. Zhou SLAC, Menlo Park, California, USA
	An accelerator test stand has been constructed at SLAC to characterize laser-assisted photocathode processing, electron beam emission physics and front-end rf gun performance. The objective of the research program is to identify definitive ‘recipes’ for high-reliability cathode preparation resulting in high quantum efficiency and low beam emittance. In this paper we report on timing, optics and instrumentation for the Ti:Sapphire drive laser, diagnostics for the 1.6 cell photocathode gun and instrumentation for the resulting electron beam. The latter include a Faraday cup charge monitor, scintillator screen beam imaging for direct emittance measurements, and high-resolution imaging of the photocathode surface to diagnose the impact of laser processing for enhanced quantum efficiency.

WEPF24	Charge Monitors at the Relativistic Electron Gun for Atomic Exploration – REGAE	electron, laser, diagnostics, DESY	868
	H. Delsim-Hashemi, K. Flöttmann, M. Seebach DESY, Hamburg, Germany S. Bayesteh Uni HH, Hamburg, Germany
	A new linac is commissioned at DESY mainly as the electron source for femtosecond electron diffraction facility REGAE (Relativistic Electron Gun for Atomic Exploration). REGAE comprises a photo-cathode gun followed by normal conducting 1.5 cell rf-cavity to provide sub pC charge electron-bunches of 2-5 MeV with a coherence length of 30nm. In order to produce and maintain such electron bunches, sophisticated single-shot diagnostics are desired e.g. emittance, energy, energy-spread and bunch-length measurement. There are three methods at REGAE for charge measurement. The most routine method is based on Faraday-cups that are distributed along machine and can provide charge reading down to ~50 fC. The second method, which is non-destructive, is a cavity based antenna that measures beam induced fields. A third method is based on beam-profile measurement diagnostics. By proper calibration of integral intensity that arrives at detector one can measure charges down to fC level. The last method has the potential to reach the limit of few electrons charge when state-of-the-art intensifiers are used in profile monitors.

Paper

Title

Other Keywords

Page

MOAL4

First Results from the Bunch Arrival-Time Monitor at the SwissFEL Test Injector

pick-up, laser, feedback, electron

8

V.R. Arsov, M.M. Dehler, S. Hunziker, M.G. Kaiser, V. Schlott
PSI, Villigen PSI, Switzerland

Non-destructive electron bunch arrival-time monitors (BAMs) with resolution <10 fs, sensitivity down to 10 pC and high intrinsic bandwidth for double bunch detection are required for reliable operation of SwissFEL. To achieve this ultimate goal, such a monitor based on a Mach-Zehnder electro-optical intensity modulator has been under development at the SwissFEL Test Injector. The high timing precision is derived by a stable pulsed optical reference system. The first BAM is located before the bunch compressor where the bunch energy is 230 MeV and the pulse length is approximately 3 ps. At this position, the bunch arrival time is sensitive to the laser- and gun timing. In this paper, we report on the commissioning of the RF- and optical front ends, the first arrival-time jitter and drift measurements with the entire system, as well as correlation of the arrival-time with different machine and environmental parameters. We achieve a resolution of 20 fs down to 60 pC.

Slides MOAL4 [1.228 MB]

MOPF27

A Beam Current Monitor for the VECC Accelerator

linac, diagnostics, vacuum, radiation

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]

TUPC03

Commissioning and Diagnostics Development for the New Short-Pulse Injector Laser at FLASH

laser, emittance, electron, SASE

353

T. Plath, J. Rönsch-Schulenburg, J. Roßbach
Uni HH, Hamburg, Germany
H. Schlarb, S. Schreiber, B. Steffen
DESY, Hamburg, Germany

In order to extend the parameter range of FLASH towards shorter electron pulses down to a few fs SASE pulses, shorter bunches with very small charges of a few tens of picocoulombs are necessary directly at the photo injector. Therefore a new injector laser delivering pulses of 1 to 5 ps has been installed and commissioned. The influence of the laser parameters on the electron beam was studied theoretically. In this paper we discuss the required laser beam diagnostics and present measurements of critical laser and electron beam parameters.

Poster TUPC03 [1.076 MB]

TUPC05

Laser and Photocathode Gun Instrumentation for the ASTA Accelerator Test Stand at SLAC

laser, cathode, LCLS, SLAC

357

J. Sheppard, W.J. Corbett, S. Gilevich, E.N. Jongewaard, J.R. Lewandowski, P. Stefan, T. Vecchione, S.P. Weathersby, F. Zhou
SLAC, Menlo Park, California, USA

An accelerator test stand has been constructed at SLAC to characterize laser-assisted photocathode processing, electron beam emission physics and front-end rf gun performance. The objective of the research program is to identify definitive ‘recipes’ for high-reliability cathode preparation resulting in high quantum efficiency and low beam emittance. In this paper we report on timing, optics and instrumentation for the Ti:Sapphire drive laser, diagnostics for the 1.6 cell photocathode gun and instrumentation for the resulting electron beam. The latter include a Faraday cup charge monitor, scintillator screen beam imaging for direct emittance measurements, and high-resolution imaging of the photocathode surface to diagnose the impact of laser processing for enhanced quantum efficiency.

WEPF24

Charge Monitors at the Relativistic Electron Gun for Atomic Exploration – REGAE

electron, laser, diagnostics, DESY

868

H. Delsim-Hashemi, K. Flöttmann, M. Seebach
DESY, Hamburg, Germany
S. Bayesteh
Uni HH, Hamburg, Germany

A new linac is commissioned at DESY mainly as the electron source for femtosecond electron diffraction facility REGAE (Relativistic Electron Gun for Atomic Exploration). REGAE comprises a photo-cathode gun followed by normal conducting 1.5 cell rf-cavity to provide sub pC charge electron-bunches of 2-5 MeV with a coherence length of 30nm. In order to produce and maintain such electron bunches, sophisticated single-shot diagnostics are desired e.g. emittance, energy, energy-spread and bunch-length measurement. There are three methods at REGAE for charge measurement. The most routine method is based on Faraday-cups that are distributed along machine and can provide charge reading down to ~50 fC. The second method, which is non-destructive, is a cavity based antenna that measures beam induced fields. A third method is based on beam-profile measurement diagnostics. By proper calibration of integral intensity that arrives at detector one can measure charges down to fC level. The last method has the potential to reach the limit of few electrons charge when state-of-the-art intensifiers are used in profile monitors.