LINAC2016 - List of Keywords (radio-frequency)

Paper	Title	Other Keywords	Page
MOPLR036	Study on Multilayer Thin Film Coating on Superconducting Cavity	cryogenics, operation, electromagnetic-fields, controls	215
	Y. Iwashita, Y. Fuwa, H. Tongu Kyoto ICR, Uji, Kyoto, Japan H. Hayano, T. Kubo, T. Saeki KEK, Ibaraki, Japan M. Hino Kyoto University, Research Reactor Institute, Osaka, Japan H. Oikawa Utsunomiya University, Utsunomiya, Japan
	Funding: This research is supported by following programs: Grant-in-Aid for Exploratory Research 26600142 and Photon and Quantum Basic Research Coordinated Development Program from the MEXT. Multilayer thin film coating is a promising technology to enhance performance of superconducting cavities. Until recently, principal parameters to achieve the sufficient performance had not been known, such as the thickness of each layer. We proposed a method to deduce a set of the parameters to exhibit a good performances. In order to verify the scheme, we are trying to make some experiments on the subject at Kyoto. The sample preparation and the test setup for the measurement apparatus will be discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-MOPLR036
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TUPRC025	Low Temperature Nitrogen Baking of a Q0 SRF Cavities	cavity, niobium, SRF, impedance	472
	P.N. Koufalis, F. Furuta, M. Ge, D. Gonnella, J.J. Kaufman, M. Liepe, J.T. Maniscalco, R.D. Porter Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Nitrogen-doping has led to an unprecedented increase in the intrinsic quality factor of bulk-niobium superconducting RF cavities. So far, high temperature baking in a nitrogen atmosphere is used almost exclusively to dope cavities. Recently, we have set focus on low temperature baking to produce similar performance increases and we present those results here.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-TUPRC025
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THPRC011	Single LLRF for Multi-Harmonic Buncher	controls, LLRF, pick-up, experiment	789
	N.R. Usher, D.M. Alt, J.F. Brandon, D.G. Morris, S. Zhao FRIB, East Lansing, Michigan, USA D.M. Alt NSCL, East Lansing, Michigan, USA
	Funding: Work supported by Michigan State University, National Science Foundation: NSF Award Number PHY-1102511. In this paper, a unique low level radio frequency (LLRF) controller designed for a multi-harmonic buncher (MHB) is presented. Different than conventional designs, the single LLRF output contains three RF frequencies (f1, f2 = 2f1, f3 = 3f1) and is fed to a wide band amplifier driving the MHB. The challenge is while driving f1, due to the non-linearity of the amplifier, the f2 and f3 terms will also be generated and will couple into the control of these two modes. Hence an active cancellation algorithm is used to suppress the nonlinear effect of the amplifier. It is demonstrated in a test that the designed LLRF is able to control the amplitude and phase of the three modes in-dependently.
	Poster THPRC011 [1.944 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-THPRC011
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THPLR048	Development of a Digital LLRF Control System at LNL	FPGA, controls, cavity, LLRF	966
	S. Pavinato, M. Betti, D. Bortolato, F. Gelain, D. Marcato, D. Pedretti INFN/LNL, Legnaro (PD), Italy M.A. Bellato, R. Isocrate INFN- Sez. di Padova, Padova, Italy M. Bertocco UNIPD, Padova (PD), Italy
	The new Low-Level Radio Frequency (LLRF) control system for linear accelerator at Legnaro National Laboratories (LNL) of INFN is presently being commissioned. A digital Radio Frequency (RF) controller was implemented. Its goal is to stabilize the amplitude, the phase and the frequency of the superconducting cavities of the Linac. The resonance frequency of the low beta cavities is 80 MHz, while medium and high beta cavities resonate at 160 MHz. Each RF controller controls at the same time eight different cavities. The hardware complexity of the RF controller (RF IOC) is reduced by adopting direct RF sampling and the RF to baseband conversion method. The main hardware components are RF ADCs for the direct undersampling of the signals picked up from cavities, a Xilinx Kintek 7 FPGA for the signal processing and DACs for driving the power amplifiers and hence the cavities. In the RF IOC the serial communication between FPGA and ADCs and between FPGA and DACs is based on JESD204b standard. An RF front-end board (RFFE) is placed between cavities and the RF IOC. This is used to adapt the power level of the RF signal from the cavities to the ADCs and from the DACs to the power amplifiers. This paper addresses the LLRF control system focusing on the hardware design of the RF IOC and RFFE boards and on the first test results carried out with the new controller.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-THPLR048
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Paper

Title

Other Keywords

Page

MOPLR036

Study on Multilayer Thin Film Coating on Superconducting Cavity

cryogenics, operation, electromagnetic-fields, controls

215

Y. Iwashita, Y. Fuwa, H. Tongu
Kyoto ICR, Uji, Kyoto, Japan
H. Hayano, T. Kubo, T. Saeki
KEK, Ibaraki, Japan
M. Hino
Kyoto University, Research Reactor Institute, Osaka, Japan
H. Oikawa
Utsunomiya University, Utsunomiya, Japan

Funding: This research is supported by following programs: Grant-in-Aid for Exploratory Research 26600142 and Photon and Quantum Basic Research Coordinated Development Program from the MEXT.
Multilayer thin film coating is a promising technology to enhance performance of superconducting cavities. Until recently, principal parameters to achieve the sufficient performance had not been known, such as the thickness of each layer. We proposed a method to deduce a set of the parameters to exhibit a good performances. In order to verify the scheme, we are trying to make some experiments on the subject at Kyoto. The sample preparation and the test setup for the measurement apparatus will be discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-MOPLR036

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TUPRC025

Low Temperature Nitrogen Baking of a Q0 SRF Cavities

cavity, niobium, SRF, impedance

472

P.N. Koufalis, F. Furuta, M. Ge, D. Gonnella, J.J. Kaufman, M. Liepe, J.T. Maniscalco, R.D. Porter
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Nitrogen-doping has led to an unprecedented increase in the intrinsic quality factor of bulk-niobium superconducting RF cavities. So far, high temperature baking in a nitrogen atmosphere is used almost exclusively to dope cavities. Recently, we have set focus on low temperature baking to produce similar performance increases and we present those results here.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-TUPRC025

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reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPRC011

Single LLRF for Multi-Harmonic Buncher

controls, LLRF, pick-up, experiment

789

N.R. Usher, D.M. Alt, J.F. Brandon, D.G. Morris, S. Zhao
FRIB, East Lansing, Michigan, USA
D.M. Alt
NSCL, East Lansing, Michigan, USA

Funding: Work supported by Michigan State University, National Science Foundation: NSF Award Number PHY-1102511.
In this paper, a unique low level radio frequency (LLRF) controller designed for a multi-harmonic buncher (MHB) is presented. Different than conventional designs, the single LLRF output contains three RF frequencies (f1, f2 = 2*f1, f3 = 3*f1) and is fed to a wide band amplifier driving the MHB. The challenge is while driving f1, due to the non-linearity of the amplifier, the f2 and f3 terms will also be generated and will couple into the control of these two modes. Hence an active cancellation algorithm is used to suppress the nonlinear effect of the amplifier. It is demonstrated in a test that the designed LLRF is able to control the amplitude and phase of the three modes in-dependently.

Poster THPRC011 [1.944 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-THPRC011

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPLR048

Development of a Digital LLRF Control System at LNL

FPGA, controls, cavity, LLRF

966

S. Pavinato, M. Betti, D. Bortolato, F. Gelain, D. Marcato, D. Pedretti
INFN/LNL, Legnaro (PD), Italy
M.A. Bellato, R. Isocrate
INFN- Sez. di Padova, Padova, Italy
M. Bertocco
UNIPD, Padova (PD), Italy

The new Low-Level Radio Frequency (LLRF) control system for linear accelerator at Legnaro National Laboratories (LNL) of INFN is presently being commissioned. A digital Radio Frequency (RF) controller was implemented. Its goal is to stabilize the amplitude, the phase and the frequency of the superconducting cavities of the Linac. The resonance frequency of the low beta cavities is 80 MHz, while medium and high beta cavities resonate at 160 MHz. Each RF controller controls at the same time eight different cavities. The hardware complexity of the RF controller (RF IOC) is reduced by adopting direct RF sampling and the RF to baseband conversion method. The main hardware components are RF ADCs for the direct undersampling of the signals picked up from cavities, a Xilinx Kintek 7 FPGA for the signal processing and DACs for driving the power amplifiers and hence the cavities. In the RF IOC the serial communication between FPGA and ADCs and between FPGA and DACs is based on JESD204b standard. An RF front-end board (RFFE) is placed between cavities and the RF IOC. This is used to adapt the power level of the RF signal from the cavities to the ADCs and from the DACs to the power amplifiers. This paper addresses the LLRF control system focusing on the hardware design of the RF IOC and RFFE boards and on the first test results carried out with the new controller.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-THPLR048

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)