LINAC2014 - List of Authors (Schappert, W.)

Paper

Title

Page

Application Investigation of High Precision Measurement for Basic Cavity Parameters at ESS

149

R. Zeng
ESS, Lund, Sweden
P. Jonsson
Lund University, Lund, Sweden
W. Schappert
Fermilab, Batavia, Illinois, USA

The ESS cavity control and operation methods/algorithms are challenging due to the use of long pulse, higher beam intensity, high beam power, high gradient, uncertainties in spoke cavities and high demands for energy efficiency and availability. Suitable and effective solutions could make use of modern technologies (flexible FPGA, faster CPU, bigger memory, faster communication speed), novel measuring techniques, accurate system modeling, and advanced control concept. Those possible implementations are essential to a better understanding, and thus a better operation of ESS cavity especially SRF cavities. All these concepts rely on high precision measurement of basic cavity parameters and consequent high quality data with high resolution, high precision and completeness. This paper focuses on how high precision measurement will address the challenges at ESS on the following topics: long pulse lorentz force detuning, high precision phase and amplitude setting, heavy beam loading compensation and power overhead reduction.

MOPP055

RF Tests of Dressed 325 MHz Single-Spoke Resonators at 2 K

180

A. Hocker, E. Cullerton, B.M. Hanna, W. Schappert, A.I. Sukhanov
Fermilab, Batavia, Illinois, USA

Funding: United States Department of Energy, Contract No.DE- AC02-07CH11359
Fermilab has recently completed an upgrade to its spoke resonator test cryostat to enable testing of cavities in superfluid helium. Two single-spoke resonators with differing helium vessel designs have been tested in this new configuration. Gradient and Q0 performance was studied along with microphonics control and sensitivity of the resonant frequency to pressure variations. A description of the testing and the results obtained are presented.

Poster MOPP055 [0.437 MB]

THPP052

RF Control and DAQ Systems for Upgraded Vertical Test Facility at Fermilab

Y.M. Pischalnikov, R.H. Carcagno, F.L. Lewis, R. Nehring, R.V. Pilipenko, W. Schappert
Fermilab, Batavia, Illinois, USA

Vertical Cavity Test Facility is major testing facility for extensive High Q0 SRF cavities R&D program at FNAL. Varieties of SRF cavities (325MHz, 650MHz, 1,3GHz and 3,9GHz ; bare and dressed) can be measured at VCTF. There are capabilities to cool-down cavities with slow & fast speed. Recently FNAL upgraded VCTF with two additional Vertical Test Stand (VTS2&3). Upgraded VCTF will be main R&D and production SRF cavities testing facility for new linear colliders (LCLS II and PIP II). We provide an overview of the design features, technical parameters and first operational experience of the newest RF control and DAQ systems, capable to serve three VTS (1,2&3).

THPP057

Results of Cold Tests of the Fermilab SSR1 Cavities

979

A.I. Sukhanov, M.H. Awida, P. Berrutti, E. Cullerton, B.M. Hanna, A. Hocker, T.N. Khabiboulline, O.S. Melnychuk, D. Passarelli, R.V. Pilipenko, Y.M. Pischalnikov, L. Ristori, A.M. Rowe, W. Schappert, D.A. Sergatskov
Fermilab, Batavia, Illinois, USA

Fermilab is currently building the Project X Injector experiment (PXIE). The PXIE linac will accelerate a 1 mA H⁻ beam up to 30 MeV and serve as a testbed for validation of Project X concepts and mitigation of technical risks. A cryomodule of eight superconducting RF Single Spoke Resonators of type 1 (SSR1) cavities operating at 325 MHz is an integral part of PXIE. Ten SSR1 cavities were manufactured in industry and delivered to Fermilab. We discuss tests of nine bare SSR1 cavities at the Fermilab Vertical Test Stand (VTS). Recently, one of the SSR1 cavities was welded inside a helium jacket. Results of the test of this cavity in the Fermilab Spoke Test Cryostat (STC) are shown. We report on the measured performance parameters of SSR1 cavities achieved during the tests.

Paper	Title	Page
MOPP040	Application Investigation of High Precision Measurement for Basic Cavity Parameters at ESS	149
	R. Zeng ESS, Lund, Sweden P. Jonsson Lund University, Lund, Sweden W. Schappert Fermilab, Batavia, Illinois, USA
	The ESS cavity control and operation methods/algorithms are challenging due to the use of long pulse, higher beam intensity, high beam power, high gradient, uncertainties in spoke cavities and high demands for energy efficiency and availability. Suitable and effective solutions could make use of modern technologies (flexible FPGA, faster CPU, bigger memory, faster communication speed), novel measuring techniques, accurate system modeling, and advanced control concept. Those possible implementations are essential to a better understanding, and thus a better operation of ESS cavity especially SRF cavities. All these concepts rely on high precision measurement of basic cavity parameters and consequent high quality data with high resolution, high precision and completeness. This paper focuses on how high precision measurement will address the challenges at ESS on the following topics: long pulse lorentz force detuning, high precision phase and amplitude setting, heavy beam loading compensation and power overhead reduction.

MOPP055	RF Tests of Dressed 325 MHz Single-Spoke Resonators at 2 K	180
	A. Hocker, E. Cullerton, B.M. Hanna, W. Schappert, A.I. Sukhanov Fermilab, Batavia, Illinois, USA
	Funding: United States Department of Energy, Contract No.DE- AC02-07CH11359 Fermilab has recently completed an upgrade to its spoke resonator test cryostat to enable testing of cavities in superfluid helium. Two single-spoke resonators with differing helium vessel designs have been tested in this new configuration. Gradient and Q0 performance was studied along with microphonics control and sensitivity of the resonant frequency to pressure variations. A description of the testing and the results obtained are presented.
	Poster MOPP055 [0.437 MB]

THPP052	RF Control and DAQ Systems for Upgraded Vertical Test Facility at Fermilab
	Y.M. Pischalnikov, R.H. Carcagno, F.L. Lewis, R. Nehring, R.V. Pilipenko, W. Schappert Fermilab, Batavia, Illinois, USA
	Vertical Cavity Test Facility is major testing facility for extensive High Q0 SRF cavities R&D program at FNAL. Varieties of SRF cavities (325MHz, 650MHz, 1,3GHz and 3,9GHz ; bare and dressed) can be measured at VCTF. There are capabilities to cool-down cavities with slow & fast speed. Recently FNAL upgraded VCTF with two additional Vertical Test Stand (VTS2&3). Upgraded VCTF will be main R&D and production SRF cavities testing facility for new linear colliders (LCLS II and PIP II). We provide an overview of the design features, technical parameters and first operational experience of the newest RF control and DAQ systems, capable to serve three VTS (1,2&3).

THPP057	Results of Cold Tests of the Fermilab SSR1 Cavities	979
	A.I. Sukhanov, M.H. Awida, P. Berrutti, E. Cullerton, B.M. Hanna, A. Hocker, T.N. Khabiboulline, O.S. Melnychuk, D. Passarelli, R.V. Pilipenko, Y.M. Pischalnikov, L. Ristori, A.M. Rowe, W. Schappert, D.A. Sergatskov Fermilab, Batavia, Illinois, USA
	Fermilab is currently building the Project X Injector experiment (PXIE). The PXIE linac will accelerate a 1 mA H⁻ beam up to 30 MeV and serve as a testbed for validation of Project X concepts and mitigation of technical risks. A cryomodule of eight superconducting RF Single Spoke Resonators of type 1 (SSR1) cavities operating at 325 MHz is an integral part of PXIE. Ten SSR1 cavities were manufactured in industry and delivered to Fermilab. We discuss tests of nine bare SSR1 cavities at the Fermilab Vertical Test Stand (VTS). Recently, one of the SSR1 cavities was welded inside a helium jacket. Results of the test of this cavity in the Fermilab Spoke Test Cryostat (STC) are shown. We report on the measured performance parameters of SSR1 cavities achieved during the tests.