2011 Particle Accelerator Conference - List of Keywords (radio-frequency)

Paper	Title	Other Keywords	Page
MOP061	Stability of the MICE Muon Beam Line	proton, emittance, target, quadrupole	223
	S.D. Blot University of Chicago, Chicago, Illinois, USA
	Funding: University of Chicago The international Muon Ionization and Cooling Exper- iment (MICE) aims to demonstrate transverse beam emit- tance reduction for a muon beam. During the summer of 2010, data was taken using different configurations of the upstream beam line magnets to measure the optical pa- rameters of the muon beam and study the functionality of the beam line itself. Throughout this period of data taking, reference runs were taken with a fixed target configuration, and magnet settings which provide a muon beam with 200 MeV/c momentum and 6π 4D transverse emittance. Time of flight (TOF) detectors were used to measure many of the beam properties including emittance, particle identifi- cation, and profile. Analysis of these reference runs was carried out in order to determine the stability and repro- ducibility of the beam line data. This overall data quality check is essential to ensure the validity of measurements made so that further analysis can be carried out and that the muon beam is suitable for the MICE cooling channel.

MOP293	Performance of Analog Signal Distribution in the ATCA Based LLRF System	LLRF, controls, FEL, linac	666
	K. Czuba, L. Butkowski, S. Jabłoński, P. Przybylski, D. Sikora Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland W. Jałmużna, D.R. Makowski TUL-DMCS, Łódź, Poland T. Jezynski, F. Ludwig DESY, Hamburg, Germany
	The Low Level Radio Frequency System (LLRF) for the European X-FEL must provide exceptional stability of the accelerating RF field in the accelerating cavities. The regulation requirements of 0.01% and 0.01 degrees in amplitude and phase respectively must be achieved at a frequency of 1.3 GHz while keeping low drifts (during RF pulse). The quality of analog signal processing and distribution plays a crucial role in achieving these goals. The RF signals are connected to the Rear Transition Module (RTM), downconverted there into intermediate frequency (IF) signals and finally sampled at AMC-ADC module. The high quality of the signals (SNR, low crosstalk) must be assured across all the way. The paper presents the results of development of ATCA based LLRF system for XFEL. The special attention is paid to RTM module with downconverters and carrier board conducting analog signals to the AMC-ADC and the AMC Vector Modulator module in the presence of digital processing components (FPGA, DSP).

TUP041	Quench Dynamics in SRF Cavities: Can We Locate the Quench Origin with 2nd Sound?	cavity, SRF, instrumentation, simulation	883
	Y.B. Maximenko MIPT, Dolgoprudniy, Moscow Region, Russia D.A. Sergatskov Fermilab, Batavia, USA
	A newly developed method of locating quench in SRF cavities by detecting second-sound waves has been gaining popularity in SRF laboratories. The technique is based on measurements of time delays between the quench, as determined by the RF system, and arrival of the 2nd sound wave to the multiple detectors placed around the cavity in superfluid helium. Unlike multi-channel temperature mapping, this approach requires only few sensors and simple readout electronics; it can be used with SRF cavities of almost arbitrary shape. One of its drawbacks is that being an indirect method it requires one to solve an inverse problem to find a location of a quench. We tried to solve this inverse problem by using a parametric forward model. By analyzing the data we found that a simple model where 2nd-sound emitter is a near-singular source does not describe the physical system well enough. A time-dependent analysis of a quench process can help us to put forward a more adequate model. We present here our current algorithm to solve the inverse problem and discuss the experimental results.

TUP095	Adjustable High Power Coax Coupler without Moving Parts	solenoid, cavity, insertion, vacuum	1009
	M.L. Neubauer, A. Dudas, R. Sah Muons, Inc, Batavia, USA R. Nassiri ANL, Argonne, USA
	An RF power coupler is designed to operate without moving parts. This new concept for an adjustable coupler is applicable to operation at any radiofrequency. CW operation of such a coupler is especially challenging at lower frequencies. The basic component of the coupler is a ferrite tuner. The RF coupler has no movable parts and relies on a ferrite tuner assembly, coax TEE, and double windows to provide a VSWR of better than 1.05:1 and a bandwidth of at least 8 MHz at 1.15:1. The ferrite tuner assembly on the stub end of the coax TEE uses an applied DC magnetic field to change the Qext and the RF coupling coefficient between the RF input and the cavity. Recent work in making measurements of the loss in the ferrite and likely thermal dissipation required for 100 kW CW operation is presented.

TUP131	A New Main Injector Radio Frequency System For 2.3 MW Project X Operations	cavity, cathode, feedback, impedance	1079
	J.E. Dey, I. Kourbanis Fermilab, Batavia, USA
	Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy. For Project X Fermilab Main Injector will be required to provide up to 2.3 MW to a neutrino production target at energies between 60 and 120 GeV. To accomplish the above power levels 3 times the current beam intensity will need to be accelerated. In addition the injection energy of Main Injector will need to be as low as 6 GeV. The current 30 year old Main Injector radio frequency system will not be able to provide the required power and a new system will be required. The specifications of the new system will be described.

WEP138	Developing Software Packages for Electromagnetic Simulations	simulation, vacuum, electromagnetic-fields, scattering	1740
	J. Xu, M. Min, B. Mustapha ANL, Argonne, USA
	Funding: This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357. In addition to previous developments on parallel beam dynamics software packages, our efforts have been extended to electromagnetic simulations. These efforts include developing new software packages solving the Maxwell equations in 2D and 3D. Scalable algorithms have been used for use of ALCF supercomputers. These new solvers are based on high order numerical methods. Comparative studies of structured and unstructured grids, continuous and discontinuous Galerkin methods will be discussed. The effects of bases will also be presented. Efficiency and challenges of new software packages will be presented. Some benchmarking and simulation results will be shown.

WEP163	RF Cavity Characterization with VORPAL	cavity, simulation, electron, resonance	1797
	C. Nieter, P.J. Mullowney, C. Roark, P. Stoltz, C.D. Zhou Tech-X, Boulder, Colorado, USA F. Marhauser JLAB, Newport News, Virginia, USA
	When designing a radio frequency (RF) accelerating cavity structure various figures of merit are considered before coming to a final cavity design. These figures of merit include specific field and geometry based quantities such as the ratio of the shunt impedance to the quality factor (R/Q) or the normalized peak fields in the cavity. Other important measures of cavity performance include the peak surface fields as well as possible multipacting resonances in the cavity. High fidelity simulations of these structures can provide a good estimate of these important quantities before any cavity prototypes are built. We will present VORPAL simulations of a simple pillbox structure where these quantities can be calculated analytically and compare them to the results from the VORPAL simulations. We will then use VORPAL to calculate these figures of merit and potential multipacting resonances for two cavity designs under development at Jefferson National Lab for Project X.

THP051	An Overview of Normal Conducting Radio Frequency Projects and Manufacturing Capabilities at Radiabeam Technologies, LLC	linac, gun, simulation, controls	2214
	R.B. Agustsson, S. Boucher, X.D. Ding, L. Faillace, P. Frigola, A.Y. Murokh, S. Storms RadiaBeam, Santa Monica, USA
	Radiabeam Technologies is currently designing, engineering and fabricating 8 different Normal Conducting Radio Frequency (NCRF) accelerating and diagnostic structures. These NCRF programs include compact X-band industrial systems, laboratory grade NCRF photoinjectors, deflecting cavities and High-Gradient structures. Nearly all aspects of these NCRF structures’ lifecycle are performed in house, including design, 3D electromagnetic and thermomechanical modeling, engineering, fabrication, cleaning and RF cold testing, tuning, and RF power testing. An overview of these varied projects along with references to more detailed publications presented in this conference are provided. Details concerning specific processes applicable to all of the above mentioned RF projects are also discussed.

Paper

Title

Other Keywords

Page

MOP061

Stability of the MICE Muon Beam Line

proton, emittance, target, quadrupole

223

S.D. Blot
University of Chicago, Chicago, Illinois, USA

Funding: University of Chicago
The international Muon Ionization and Cooling Exper- iment (MICE) aims to demonstrate transverse beam emit- tance reduction for a muon beam. During the summer of 2010, data was taken using different configurations of the upstream beam line magnets to measure the optical pa- rameters of the muon beam and study the functionality of the beam line itself. Throughout this period of data taking, reference runs were taken with a fixed target configuration, and magnet settings which provide a muon beam with 200 MeV/c momentum and 6π 4D transverse emittance. Time of flight (TOF) detectors were used to measure many of the beam properties including emittance, particle identifi- cation, and profile. Analysis of these reference runs was carried out in order to determine the stability and repro- ducibility of the beam line data. This overall data quality check is essential to ensure the validity of measurements made so that further analysis can be carried out and that the muon beam is suitable for the MICE cooling channel.

MOP293

Performance of Analog Signal Distribution in the ATCA Based LLRF System

LLRF, controls, FEL, linac

666

K. Czuba, L. Butkowski, S. Jabłoński, P. Przybylski, D. Sikora
Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland
W. Jałmużna, D.R. Makowski
TUL-DMCS, Łódź, Poland
T. Jezynski, F. Ludwig
DESY, Hamburg, Germany

The Low Level Radio Frequency System (LLRF) for the European X-FEL must provide exceptional stability of the accelerating RF field in the accelerating cavities. The regulation requirements of 0.01% and 0.01 degrees in amplitude and phase respectively must be achieved at a frequency of 1.3 GHz while keeping low drifts (during RF pulse). The quality of analog signal processing and distribution plays a crucial role in achieving these goals. The RF signals are connected to the Rear Transition Module (RTM), downconverted there into intermediate frequency (IF) signals and finally sampled at AMC-ADC module. The high quality of the signals (SNR, low crosstalk) must be assured across all the way. The paper presents the results of development of ATCA based LLRF system for XFEL. The special attention is paid to RTM module with downconverters and carrier board conducting analog signals to the AMC-ADC and the AMC Vector Modulator module in the presence of digital processing components (FPGA, DSP).

TUP041

Quench Dynamics in SRF Cavities: Can We Locate the Quench Origin with 2nd Sound?

cavity, SRF, instrumentation, simulation

883

Y.B. Maximenko
MIPT, Dolgoprudniy, Moscow Region, Russia
D.A. Sergatskov
Fermilab, Batavia, USA

A newly developed method of locating quench in SRF cavities by detecting second-sound waves has been gaining popularity in SRF laboratories. The technique is based on measurements of time delays between the quench, as determined by the RF system, and arrival of the 2nd sound wave to the multiple detectors placed around the cavity in superfluid helium. Unlike multi-channel temperature mapping, this approach requires only few sensors and simple readout electronics; it can be used with SRF cavities of almost arbitrary shape. One of its drawbacks is that being an indirect method it requires one to solve an inverse problem to find a location of a quench. We tried to solve this inverse problem by using a parametric forward model. By analyzing the data we found that a simple model where 2nd-sound emitter is a near-singular source does not describe the physical system well enough. A time-dependent analysis of a quench process can help us to put forward a more adequate model. We present here our current algorithm to solve the inverse problem and discuss the experimental results.

TUP095

Adjustable High Power Coax Coupler without Moving Parts

solenoid, cavity, insertion, vacuum

1009

M.L. Neubauer, A. Dudas, R. Sah
Muons, Inc, Batavia, USA
R. Nassiri
ANL, Argonne, USA

An RF power coupler is designed to operate without moving parts. This new concept for an adjustable coupler is applicable to operation at any radiofrequency. CW operation of such a coupler is especially challenging at lower frequencies. The basic component of the coupler is a ferrite tuner. The RF coupler has no movable parts and relies on a ferrite tuner assembly, coax TEE, and double windows to provide a VSWR of better than 1.05:1 and a bandwidth of at least 8 MHz at 1.15:1. The ferrite tuner assembly on the stub end of the coax TEE uses an applied DC magnetic field to change the Qext and the RF coupling coefficient between the RF input and the cavity. Recent work in making measurements of the loss in the ferrite and likely thermal dissipation required for 100 kW CW operation is presented.

TUP131

A New Main Injector Radio Frequency System For 2.3 MW Project X Operations

cavity, cathode, feedback, impedance

1079

J.E. Dey, I. Kourbanis
Fermilab, Batavia, USA

Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.
For Project X Fermilab Main Injector will be required to provide up to 2.3 MW to a neutrino production target at energies between 60 and 120 GeV. To accomplish the above power levels 3 times the current beam intensity will need to be accelerated. In addition the injection energy of Main Injector will need to be as low as 6 GeV. The current 30 year old Main Injector radio frequency system will not be able to provide the required power and a new system will be required. The specifications of the new system will be described.

WEP138

Developing Software Packages for Electromagnetic Simulations

simulation, vacuum, electromagnetic-fields, scattering

1740

J. Xu, M. Min, B. Mustapha
ANL, Argonne, USA

Funding: This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357.
In addition to previous developments on parallel beam dynamics software packages, our efforts have been extended to electromagnetic simulations. These efforts include developing new software packages solving the Maxwell equations in 2D and 3D. Scalable algorithms have been used for use of ALCF supercomputers. These new solvers are based on high order numerical methods. Comparative studies of structured and unstructured grids, continuous and discontinuous Galerkin methods will be discussed. The effects of bases will also be presented. Efficiency and challenges of new software packages will be presented. Some benchmarking and simulation results will be shown.

WEP163

RF Cavity Characterization with VORPAL

cavity, simulation, electron, resonance

1797

C. Nieter, P.J. Mullowney, C. Roark, P. Stoltz, C.D. Zhou
Tech-X, Boulder, Colorado, USA
F. Marhauser
JLAB, Newport News, Virginia, USA

When designing a radio frequency (RF) accelerating cavity structure various figures of merit are considered before coming to a final cavity design. These figures of merit include specific field and geometry based quantities such as the ratio of the shunt impedance to the quality factor (R/Q) or the normalized peak fields in the cavity. Other important measures of cavity performance include the peak surface fields as well as possible multipacting resonances in the cavity. High fidelity simulations of these structures can provide a good estimate of these important quantities before any cavity prototypes are built. We will present VORPAL simulations of a simple pillbox structure where these quantities can be calculated analytically and compare them to the results from the VORPAL simulations. We will then use VORPAL to calculate these figures of merit and potential multipacting resonances for two cavity designs under development at Jefferson National Lab for Project X.

THP051

An Overview of Normal Conducting Radio Frequency Projects and Manufacturing Capabilities at Radiabeam Technologies, LLC

linac, gun, simulation, controls

2214

R.B. Agustsson, S. Boucher, X.D. Ding, L. Faillace, P. Frigola, A.Y. Murokh, S. Storms
RadiaBeam, Santa Monica, USA

Radiabeam Technologies is currently designing, engineering and fabricating 8 different Normal Conducting Radio Frequency (NCRF) accelerating and diagnostic structures. These NCRF programs include compact X-band industrial systems, laboratory grade NCRF photoinjectors, deflecting cavities and High-Gradient structures. Nearly all aspects of these NCRF structures’ lifecycle are performed in house, including design, 3D electromagnetic and thermomechanical modeling, engineering, fabrication, cleaning and RF cold testing, tuning, and RF power testing. An overview of these varied projects along with references to more detailed publications presented in this conference are provided. Details concerning specific processes applicable to all of the above mentioned RF projects are also discussed.