NAPAC2022 - List of Authors (Kostin, R.A.)

Paper	Title	Page
MOPA46	Cryogenic Dielectric Structure with GΩ/m Level Shunt Impedance	157
	R.A. Kostin, C. Jing Euclid Beamlabs, Bolingbrook, USA
	Shunt impedance is one of the most important parameters characterizing particle acceleration efficiency. It is known that RF losses are reduced at cryogenic temperatures. For example, a record high shunt impedance of 350 MΩ/m was demonstrated recently for all metal X-band accelerating structure, which is more than 2 times higher than that at room temperature. In this article we present a novel hybrid dielectric structure which can achieve even higher shunt impedance due to the fact that losses in dielectric materials reduced much more than in pure copper.
DOI •	reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-MOPA46
About •	Received ※ 12 August 2022 — Revised ※ 16 August 2022 — Accepted ※ 23 August 2022 — Issue date ※ 17 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEZE4	First High-Gradient Results of UED/UEM SRF Gun at Cryogenic Temperatures	607
	R.A. Kostin, C. Jing Euclid Beamlabs, Bolingbrook, USA D.J. Bice, T.N. Khabiboulline, S. Posen Fermilab, Batavia, Illinois, USA
	Funding: The project is funded by DOE SBIR #DE-SC0018621 Benefiting from the rapid progress on RF photogun technologies in the past two decades, the development of MeV range ultrafast electron diffraction/microscopy (UED and UEM) has been identified as an enabling instrumentation. UEM or UED use low power electron beams with modest energies of a few MeV to study ultrafast phenomena in a variety of novel and exotic materials. SRF photoguns become a promising candidate to produce highly stable electrons for UEM/UED applications because of the ultrahigh shot-to-shot stability compared to room temperature RF photoguns. SRF technology was prohibitively expensive for industrial use until two recent advancements: Nb₃Sn and conduction cooling. The use of Nb₃Sn allows to operate SRF cavities at higher temperatures (4K) with low power dissipation which is within the reach of commercially available closed-cycle cryocoolers. Euclid is developing a continuous wave (CW), 1.5-cell, MeV-scale SRF conduction cooled photogun operating at 1.3 GHz. In this paper, we present first high gradient results of the gun conducted in liquid helium.
	Slides WEZE4 [2.817 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-WEZE4
About •	Received ※ 05 August 2022 — Revised ※ 07 August 2022 — Accepted ※ 11 August 2022 — Issue date ※ 29 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPA52	Demonstration of Twice-Reduced Lorentz-Force Detuning in SRF Cavity by Copper Cold Spraying	749
	R.A. Kostin, C.-J. Jing, A. Kanareykin Euclid TechLabs, Solon, Ohio, USA G. Ciovati JLab, Newport News, Virginia, USA
	Funding: The project is funded by DOE SBIR # DE-SC0019589 Superconducting RF (SRF) cavities usually are made from thin-walled high RRR Niobium and are susceptible to Lorentz Force Detuning (LFD) ’ cavity deformation phenomena by RF fields. In this paper, we present high gradient cryogenic results of an SRF cavity with two times reduced LFD achieved by copper cold spray reinforcement without sacrificing cavity flexibility for tuning. Finite-element model was developed first to find the best geometry for LFD reduction, which incorporated coupled RF, structural and thermal modules, and is also presented.
DOI •	reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-WEPA52
About •	Received ※ 27 July 2022 — Revised ※ 03 August 2022 — Accepted ※ 09 August 2022 — Issue date ※ 16 August 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THYE4	Development of an Ultra-Low Vibration Cryostat Based on a Closed-Cycle Cryocooler	874
	R.W. Roca Illinois Institute of Technology, Chicago, Illinois, USA E.W. Knight, R.A. Kostin, Y. Zhao Euclid TechLabs, Solon, Ohio, USA
	Low temperature and low vibration cryostats are useful in a variety of applications such as x-ray diffraction, quantum computing, x-ray monochromators and cryo-TEMs. In this project, we explore an ultra-low vibration cryostat with the cooling provided by a closed cycle cryocooler. Closed-cycle cryocoolers inevitably introduce vibrations into the system, and in this project, flexible copper braiding was used to decouple vibrations and provide cooling at the same time. In order to develop the cryostat, capacity map of a two stage Sumitomo cryocooler was measured as well as vibration transmission through different copper braids using an IR interferometer. This paper covers the capacity map and vibration measurements in the first prototype.
	Slides THYE4 [4.989 MB]
DOI •	reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-THYE4
About •	Received ※ 16 July 2022 — Revised ※ 10 August 2022 — Accepted ※ 20 August 2022 — Issue date ※ 12 September 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Cryogenic Dielectric Structure with GΩ/m Level Shunt Impedance

157

R.A. Kostin, C. Jing
Euclid Beamlabs, Bolingbrook, USA

Shunt impedance is one of the most important parameters characterizing particle acceleration efficiency. It is known that RF losses are reduced at cryogenic temperatures. For example, a record high shunt impedance of 350 MΩ/m was demonstrated recently for all metal X-band accelerating structure, which is more than 2 times higher than that at room temperature. In this article we present a novel hybrid dielectric structure which can achieve even higher shunt impedance due to the fact that losses in dielectric materials reduced much more than in pure copper.

DOI •

reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-MOPA46

About •

Received ※ 12 August 2022 — Revised ※ 16 August 2022 — Accepted ※ 23 August 2022 — Issue date ※ 17 September 2022

Cite •

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

WEZE4

First High-Gradient Results of UED/UEM SRF Gun at Cryogenic Temperatures

607

R.A. Kostin, C. Jing
Euclid Beamlabs, Bolingbrook, USA
D.J. Bice, T.N. Khabiboulline, S. Posen
Fermilab, Batavia, Illinois, USA

Funding: The project is funded by DOE SBIR #DE-SC0018621
Benefiting from the rapid progress on RF photogun technologies in the past two decades, the development of MeV range ultrafast electron diffraction/microscopy (UED and UEM) has been identified as an enabling instrumentation. UEM or UED use low power electron beams with modest energies of a few MeV to study ultrafast phenomena in a variety of novel and exotic materials. SRF photoguns become a promising candidate to produce highly stable electrons for UEM/UED applications because of the ultrahigh shot-to-shot stability compared to room temperature RF photoguns. SRF technology was prohibitively expensive for industrial use until two recent advancements: Nb₃Sn and conduction cooling. The use of Nb₃Sn allows to operate SRF cavities at higher temperatures (4K) with low power dissipation which is within the reach of commercially available closed-cycle cryocoolers. Euclid is developing a continuous wave (CW), 1.5-cell, MeV-scale SRF conduction cooled photogun operating at 1.3 GHz. In this paper, we present first high gradient results of the gun conducted in liquid helium.

Slides WEZE4 [2.817 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-WEZE4

About •

Received ※ 05 August 2022 — Revised ※ 07 August 2022 — Accepted ※ 11 August 2022 — Issue date ※ 29 September 2022

Cite •

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

WEPA52

Demonstration of Twice-Reduced Lorentz-Force Detuning in SRF Cavity by Copper Cold Spraying

749

R.A. Kostin, C.-J. Jing, A. Kanareykin
Euclid TechLabs, Solon, Ohio, USA
G. Ciovati
JLab, Newport News, Virginia, USA

Funding: The project is funded by DOE SBIR # DE-SC0019589
Superconducting RF (SRF) cavities usually are made from thin-walled high RRR Niobium and are susceptible to Lorentz Force Detuning (LFD) ’ cavity deformation phenomena by RF fields. In this paper, we present high gradient cryogenic results of an SRF cavity with two times reduced LFD achieved by copper cold spray reinforcement without sacrificing cavity flexibility for tuning. Finite-element model was developed first to find the best geometry for LFD reduction, which incorporated coupled RF, structural and thermal modules, and is also presented.

DOI •

reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-WEPA52

About •

Received ※ 27 July 2022 — Revised ※ 03 August 2022 — Accepted ※ 09 August 2022 — Issue date ※ 16 August 2022

Cite •

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

THYE4

Development of an Ultra-Low Vibration Cryostat Based on a Closed-Cycle Cryocooler

874

R.W. Roca
Illinois Institute of Technology, Chicago, Illinois, USA
E.W. Knight, R.A. Kostin, Y. Zhao
Euclid TechLabs, Solon, Ohio, USA

Low temperature and low vibration cryostats are useful in a variety of applications such as x-ray diffraction, quantum computing, x-ray monochromators and cryo-TEMs. In this project, we explore an ultra-low vibration cryostat with the cooling provided by a closed cycle cryocooler. Closed-cycle cryocoolers inevitably introduce vibrations into the system, and in this project, flexible copper braiding was used to decouple vibrations and provide cooling at the same time. In order to develop the cryostat, capacity map of a two stage Sumitomo cryocooler was measured as well as vibration transmission through different copper braids using an IR interferometer. This paper covers the capacity map and vibration measurements in the first prototype.

Slides THYE4 [4.989 MB]

DOI •

reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-THYE4

About •

Received ※ 16 July 2022 — Revised ※ 10 August 2022 — Accepted ※ 20 August 2022 — Issue date ※ 12 September 2022

Cite •

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