Effect of low temperature baking in nitrogen on the performance of a niobium superconducting radio frequency cavity

被引：32

作者：

Dhakal, Pashupati ^{[1
]}

Chetri, Santosh ^{[2
]}

Balachandran, Shreyas ^{[2
]}

Lee, Peter J. ^{[2
]}

Ciovati, Gianluigi ^{[1
]}

机构：

[1] Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA

[2] Natl High Magnet Field Lab, Appl Superconduct Ctr, Tallahassee, FL 32310 USA

来源：

PHYSICAL REVIEW ACCELERATORS AND BEAMS | 2018年 / 21卷 / 03期

关键词：

HYDROGEN; OXYGEN;

D O I：

10.1103/PhysRevAccelBeams.21.032001

中图分类号：

O57 [原子核物理学、高能物理学];

学科分类号：

070202 ;

摘要：

We report the rf performance of a single cell superconducting radiofrequency cavity after low temperature baking in a nitrogen environment. A significant increase in quality factor has been observed when the cavity was heat treated in the temperature range of 120-160 degrees C with a nitrogen partial pressure of similar to 25 m Torr. This increase in quality factor as well as the Q-rise phenomenon (anti-Q-slope) is similar to those previously obtained with high temperature nitrogen doping as well as titanium doping. In this study, a cavity N-2-treated at 120 degrees C and at 140 degrees C showed no degradation in accelerating gradient, however the accelerating gradient was reduced by similar to 25% with a 160 degrees C N-2 treatment, compared to the baseline tests after electropolishing. Sample coupons treated in the same conditions as the cavity were analyzed by scanning electron microscope, x-ray photoelectron spectroscopy and secondary ion mass spectroscopy revealed a complex surface composition of Nb2O5, NbO and NbN(1-x)Ox within the rf penetration depth. Furthermore, magnetization measurements showed no significant change on bulk superconducting properties.

引用

页数：10

共 36 条

[1]

[Anonymous], 2016, P 7 INT PART ACC C B

[2]

Balachandran S., 2017, SRF 17

[3] Time-of-flight secondary ion mass spectrometry: techniques and applications for the characterization of biomaterial surfaces [J].

Belu, AM ;

Graham, DJ ;

Castner, DG .

BIOMATERIALS, 2003, 24 (21) :3635-3653

[4]

Checchin M., 2016, Proc. of the 7th International Particle Accelerator Conference, P2254, DOI DOI 10.18429/JACOW-IPAC2016-WEPMR002

[5]

Chetri S., 2015, P SRF 2015 WHISTL BC

[6] Effect of low-temperature baking on the radio-frequency properties of niobium superconducting cavities for particle accelerators [J].

Ciovati, G .

JOURNAL OF APPLIED PHYSICS, 2004, 96 (03) :1591-1600

[7] Decrease of the surface resistance in superconducting niobium resonator cavities by the microwave field [J].

Ciovati, G. ;

Dhakal, P. ;

Gurevich, A. .

APPLIED PHYSICS LETTERS, 2014, 104 (09)

[8] High field Q slope and the baking effect: Review of recent experimental results and new data on Nb heat treatments [J].

Ciovati, G. ;

Myneni, G. ;

Stevie, F. ;

Maheshwari, P. ;

Griffis, D. .

PHYSICAL REVIEW SPECIAL TOPICS-ACCELERATORS AND BEAMS, 2010, 13 (02)

[9] Improved oxygen diffusion model to explain the effect of low-temperature baking on high field losses in niobium superconducting cavities [J].

Ciovati, Gianluigi .

APPLIED PHYSICS LETTERS, 2006, 89 (02)

[10]

Clem J.R., 1974, POCEEDINGS 13 INT C, V3, P102

← 1 2 3 4 →