SRF2013 - List of Authors (Terechkine, I.)

Paper

Title

Page

Status of the SRF Development for the Project X

117

V.P. Yakovlev, T.T. Arkan, M.H. Awida, P. Berrutti, E. Borissov, A.C. Crawford, M.H. Foley, C.M. Ginsburg, I.V. Gonin, A. Grassellino, C.J. Grimm, S.D. Holmes, S. Kazakov, R.D. Kephart, T.N. Khabiboulline, V.A. Lebedev, A. Lunin, M. Merio, S. Nagaitsev, T.H. Nicol, Y.O. Orlov, D. Passarelli, T.J. Peterson, Y.M. Pischalnikov, O.V. Pronitchev, L. Ristori, A.M. Rowe, D.A. Sergatskov, N. Solyak, A.I. Sukhanov, I. Terechkine
Fermilab, Batavia, USA

Project X is a high intensity proton facility being developed to support a world-leading program of Intensity Frontier physics over the next two decades at Fermilab. The proposed facility is based on the SRF technology and consists of two linacs: CW linac to accelerate beam from 2.1 MeV to 3 GeV and pulsed linac accelerate 5% of the beam up to 8 GeV. In a CW linac five families of SC cavities are used: half-wave resonators (162.5 MHz); single-spoke cavities: SSR1 and SSR2 (325 MHz) and elliptical 5-cell β=0.6 and β=0.9 cavities (650 MHz). Pulsed 3-8 GeV linac linac are based on 9-cell 1.3 GHz cavities. In the paper the basic requirements and the status of development of SC accelerating cavities, auxiliaries (couplers, tuners, etc.) and cryomodules are presented as well as technology challenges caused by their specifics.

MOP090

Feasibility of Using Conductively Cooled Magnets in Cryomodules of Superconducting Linacs

361

I. Terechkine, S. Cheban, T.H. Nicol, V. Poloubotko, D.A. Sergatskov
Fermilab, Batavia, USA

While trying to find an optimal way to configure cryomodule for the low energy part of a high-current, high-power superconducting linac, an option of using conductively cooled superconducting focusing lenses was evaluated. As part of this evaluation, several tests were made using existing test cryostat. The cryostat was modified by adding current feed-throughs and two conductively cooled current leads, each equipped with heat sinks at the temperatures of liquid nitrogen and liquid helium. A superconducting magnet was mounted inside the cryostat on an individual heat sink, and thermometers were installed on the leads, heat sinks, and on the magnet’s winding. In this report we provide some details of the heat exchangers’ designs, compare predicted and measured temperature distribution along the leads, and analyze results of the winding temperature measurements.

TUP040

Quench Dynamics in SRF Cavities

D.A. Sergatskov, I. Terechkine, V.P. Yakovlev
Fermilab, Batavia, USA
S. Antipov
University of Chicago, Chicago, Illinois, USA
E. Toropov
CMU, Pittsburgh, Pennsylvania, USA

Funding: The work herein has been performed at Fermilab, which is operated by Fermi Research Alliance, LLC under Contract with the United States Department of Energy.
A quench in SRF cavities is a thermal runaway process that causes a rapid loss of the stored RF energy. A quench is one of the factors that limits performance of the cavity. We have developed a comprehensive model describing the thermal and electromagnetic dynamics in the quench zone of an SRF cavity. The model has already provided us with insights essential to improved performance of SRF cavities. The predicted size of the hot spot that emits 2nd-sound during the quench is important for the Oscillating Sound Transducer (OST) quench detection technique; the maximum size of the normal zone formed during the quench determines cavity quality degradation; anomalous RF decay time distinguishes a real quench from other mechanisms of sudden loss of RF power in the cavities. We describe the model, discuss the most important results and compare them to experimental data.

THP047

Performance Degradation of a Superconducting Cavity Quenching in Magnetic Field

1013

I. Terechkine, T.N. Khabiboulline, D.A. Sergatskov
Fermilab, Batavia, USA

Although degradation of a superconducting RF (SRF) cavity performance induced by magnetic field trapped in its walls is a well understood phenomenon, a criterion for an acceptable level of magnetic field existing in the vicinity of an SRF cavity and generated after the cavity is cooled down has not been agreed upon. The bulk of superconducting Nb should protect the RF surface of the cavity from the magnetic field on the outside; nevertheless a failure mode exists when the cavity quenches while the external field is applied. The amount of trapped magnetic flux in this case depends on the size of normally conducting zone developed in walls of the cavity during quenching. Although propagation of the normally conducting zone in walls of a cavity can be modeled, no dedicated studies of this process that would include experimental verifications of its impact on the cavity performance could be found. We tried to address his issue in a special study by using as an example a superconducting coil mounted near a quenching cavity; the method and some results of the study can be applied to any RF structure and magnetic system.

Paper	Title	Page
MOP015	Status of the SRF Development for the Project X	117
	V.P. Yakovlev, T.T. Arkan, M.H. Awida, P. Berrutti, E. Borissov, A.C. Crawford, M.H. Foley, C.M. Ginsburg, I.V. Gonin, A. Grassellino, C.J. Grimm, S.D. Holmes, S. Kazakov, R.D. Kephart, T.N. Khabiboulline, V.A. Lebedev, A. Lunin, M. Merio, S. Nagaitsev, T.H. Nicol, Y.O. Orlov, D. Passarelli, T.J. Peterson, Y.M. Pischalnikov, O.V. Pronitchev, L. Ristori, A.M. Rowe, D.A. Sergatskov, N. Solyak, A.I. Sukhanov, I. Terechkine Fermilab, Batavia, USA
	Project X is a high intensity proton facility being developed to support a world-leading program of Intensity Frontier physics over the next two decades at Fermilab. The proposed facility is based on the SRF technology and consists of two linacs: CW linac to accelerate beam from 2.1 MeV to 3 GeV and pulsed linac accelerate 5% of the beam up to 8 GeV. In a CW linac five families of SC cavities are used: half-wave resonators (162.5 MHz); single-spoke cavities: SSR1 and SSR2 (325 MHz) and elliptical 5-cell β=0.6 and β=0.9 cavities (650 MHz). Pulsed 3-8 GeV linac linac are based on 9-cell 1.3 GHz cavities. In the paper the basic requirements and the status of development of SC accelerating cavities, auxiliaries (couplers, tuners, etc.) and cryomodules are presented as well as technology challenges caused by their specifics.

MOP090	Feasibility of Using Conductively Cooled Magnets in Cryomodules of Superconducting Linacs	361
	I. Terechkine, S. Cheban, T.H. Nicol, V. Poloubotko, D.A. Sergatskov Fermilab, Batavia, USA
	While trying to find an optimal way to configure cryomodule for the low energy part of a high-current, high-power superconducting linac, an option of using conductively cooled superconducting focusing lenses was evaluated. As part of this evaluation, several tests were made using existing test cryostat. The cryostat was modified by adding current feed-throughs and two conductively cooled current leads, each equipped with heat sinks at the temperatures of liquid nitrogen and liquid helium. A superconducting magnet was mounted inside the cryostat on an individual heat sink, and thermometers were installed on the leads, heat sinks, and on the magnet’s winding. In this report we provide some details of the heat exchangers’ designs, compare predicted and measured temperature distribution along the leads, and analyze results of the winding temperature measurements.

TUP040	Quench Dynamics in SRF Cavities
	D.A. Sergatskov, I. Terechkine, V.P. Yakovlev Fermilab, Batavia, USA S. Antipov University of Chicago, Chicago, Illinois, USA E. Toropov CMU, Pittsburgh, Pennsylvania, USA
	Funding: The work herein has been performed at Fermilab, which is operated by Fermi Research Alliance, LLC under Contract with the United States Department of Energy. A quench in SRF cavities is a thermal runaway process that causes a rapid loss of the stored RF energy. A quench is one of the factors that limits performance of the cavity. We have developed a comprehensive model describing the thermal and electromagnetic dynamics in the quench zone of an SRF cavity. The model has already provided us with insights essential to improved performance of SRF cavities. The predicted size of the hot spot that emits 2nd-sound during the quench is important for the Oscillating Sound Transducer (OST) quench detection technique; the maximum size of the normal zone formed during the quench determines cavity quality degradation; anomalous RF decay time distinguishes a real quench from other mechanisms of sudden loss of RF power in the cavities. We describe the model, discuss the most important results and compare them to experimental data.

THP047	Performance Degradation of a Superconducting Cavity Quenching in Magnetic Field	1013
	I. Terechkine, T.N. Khabiboulline, D.A. Sergatskov Fermilab, Batavia, USA
	Although degradation of a superconducting RF (SRF) cavity performance induced by magnetic field trapped in its walls is a well understood phenomenon, a criterion for an acceptable level of magnetic field existing in the vicinity of an SRF cavity and generated after the cavity is cooled down has not been agreed upon. The bulk of superconducting Nb should protect the RF surface of the cavity from the magnetic field on the outside; nevertheless a failure mode exists when the cavity quenches while the external field is applied. The amount of trapped magnetic flux in this case depends on the size of normally conducting zone developed in walls of the cavity during quenching. Although propagation of the normally conducting zone in walls of a cavity can be modeled, no dedicated studies of this process that would include experimental verifications of its impact on the cavity performance could be found. We tried to address his issue in a special study by using as an example a superconducting coil mounted near a quenching cavity; the method and some results of the study can be applied to any RF structure and magnetic system.