SRF2019 - List of Authors (Ivanov, A.E.)

Paper	Title	Page
THP078	CERN’s SRF Test Stand for Cavity Performance Measurements	1082
	N. Stapley, J. Bastard, M.R. Coly, A.E. Ivanov, A. Macpherson, N.C. Shipman, K. Turaj CERN, Geneva, Switzerland I. Ben-Zvi BNL, Upton, New York, USA A. Castilla Cockcroft Institute, Lancaster University, Lancaster, United Kingdom K. Hernandez-Chahin Universidad de Guanajuato, División de Ciencias e Ingenierías, León, Mexico M. Wartak, A. Zwozniak IFJ-PAN, Kraków, Poland
	Recent deployment of a digital LLRF system within the cavity testing framework of CERN’s vertical test cryostats has permitted a full revamp of cavity performance validation. With both full continuous and pulse mode operation, steady state a transient RF behaviour can be effectively probed. Due to direct and integrated control and monitoring of environmental test conditions, standard and novel RF measurement procedures have been developed and integrated into the testing infrastructure, along with a coherent data flow of high granularity measurement data. We present an overview of this cavity measurement system and address the underlying architectural structure, data handling and integration of user interfaces. In addition we highlight the benefits of variety of RF cavity measurements that can now be accommodated in our large 2 K cryostats.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP078
About •	paper received ※ 23 June 2019 paper accepted ※ 30 June 2019 issue date ※ 14 August 2019
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THP095	Direct Measurement of Thermoelectric Currents During Cool Down	1139
	A.E. Ivanov, F. Gerigk, A. Macpherson CERN, Geneva, Switzerland
	In recent years there has been much discussion on thermoelectric effects and their role in flux expulsion during cool down of SRF cavities. Magnetic field is often measured to asses both flux expulsion as the cavity undergoes superconducting transition, and thermoelectric currents due to spatial thermal gradients. As a complementary view, in this paper we show direct measurement of the thermoelectric current independent from the expulsion measurement of the magnetic field. In our setup the azimuthally symmetric cavity is vertically installed and the thermal gradient is along the symmetry axis allowing to describe the cool down behavior of the thermoelectric current using simple coupled simulations.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP095
About •	paper received ※ 21 June 2019 paper accepted ※ 30 June 2019 issue date ※ 14 August 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

CERN’s SRF Test Stand for Cavity Performance Measurements

1082

N. Stapley, J. Bastard, M.R. Coly, A.E. Ivanov, A. Macpherson, N.C. Shipman, K. Turaj
CERN, Geneva, Switzerland
I. Ben-Zvi
BNL, Upton, New York, USA
A. Castilla
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
K. Hernandez-Chahin
Universidad de Guanajuato, División de Ciencias e Ingenierías, León, Mexico
M. Wartak, A. Zwozniak
IFJ-PAN, Kraków, Poland

Recent deployment of a digital LLRF system within the cavity testing framework of CERN’s vertical test cryostats has permitted a full revamp of cavity performance validation. With both full continuous and pulse mode operation, steady state a transient RF behaviour can be effectively probed. Due to direct and integrated control and monitoring of environmental test conditions, standard and novel RF measurement procedures have been developed and integrated into the testing infrastructure, along with a coherent data flow of high granularity measurement data. We present an overview of this cavity measurement system and address the underlying architectural structure, data handling and integration of user interfaces. In addition we highlight the benefits of variety of RF cavity measurements that can now be accommodated in our large 2 K cryostats.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP078

About •

paper received ※ 23 June 2019 paper accepted ※ 30 June 2019 issue date ※ 14 August 2019

Export •

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

THP095

Direct Measurement of Thermoelectric Currents During Cool Down

1139

A.E. Ivanov, F. Gerigk, A. Macpherson
CERN, Geneva, Switzerland

In recent years there has been much discussion on thermoelectric effects and their role in flux expulsion during cool down of SRF cavities. Magnetic field is often measured to asses both flux expulsion as the cavity undergoes superconducting transition, and thermoelectric currents due to spatial thermal gradients. As a complementary view, in this paper we show direct measurement of the thermoelectric current independent from the expulsion measurement of the magnetic field. In our setup the azimuthally symmetric cavity is vertically installed and the thermal gradient is along the symmetry axis allowing to describe the cool down behavior of the thermoelectric current using simple coupled simulations.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-THP095

About •

paper received ※ 21 June 2019 paper accepted ※ 30 June 2019 issue date ※ 14 August 2019

Export •

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