KUBO, Takayuki

J-GLOBAL         Last updated: Dec 9, 2019 at 11:25
 
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Name
KUBO, Takayuki
Affiliation
KEK, High Energy Accelerator Research Organization
Job title
Assistant Professor
Degree
Ph. D. in Physics
Other affiliation
The Graduate University for Advanced Studies
Research funding number
30712666

Profile

I am a physicist at KEK, trying to understand physics of the superconducting radio-frequency (SRF) particle accelerator cavity. The SRF cavity is one of the key components of modern particle accelerators. Its performance is described by the peak surface magnetic field, Bp, and the quality factor, Q0. The former is proportional to the average electric field that the charged particles see during transit, which determines the necessary accelerator length to achieve a target particle energy. The latter is the ratio of stored energy to dissipation per RF cycle. Improvements of both the parameters are vital challenges for a future high-energy accelerator, such as the International Linear Collider (ILC) 1TeV upgrades.
The study of SRF cavity has a half-century of history, but its theory leaves many fundamental questions unanswered: the fundamental limitation of Bp of cavity made of the traditional and alternative materials, the behavior of Q0 as a function of Bp, and its surface treatment dependences, etc. Understanding physics behind these phenomena must be clues to improving the performance of SRF cavity.

Research Areas

 
 

Academic & Professional Experience

 
Apr 2019
 - 
Today
Assistant Professor, Center for Applied Superconducting Accelerator, KEK (High Energy Accelerator Research Organization)
 
Aug 2017
 - 
Jul 2019
Visiting Faculty, Department of Physics, Old Dominion University
 
Apr 2015
 - 
Today
Assistant Professor, SOKENDAI (The Graduate University for Advanced Studies)
 
Apr 2015
 - 
Mar 2019
Assistant Professor, KEK (High Energy Accelerator Research Organization)
 
Apr 2014
 - 
Mar 2015
Researcher, KEK (High Energy Accelerator Research Organization)
 
Apr 2012
 - 
Mar 2014
Postdoctral Fellow, KEK (High Energy Accelerator Research Organization)
 
Apr 2010
 - 
Mar 2012
Government Official (Class I ); quit on Mar 2012
 

Education

 
Apr 2007
 - 
Mar 2010
Ph.D. in physics (particle physics theory), the Graduate University for Advanced Studies, KEK
 
Apr 2005
 - 
Mar 2007
Graduate School, Kyoto University
 
Apr 2001
 - 
Mar 2005
Kyoto University
 

Awards & Honors

 
Jun 2018
Highlights of 2017, Superconductor Science and Technology, United Kingdom
 
Multilayer coating for higher accelerating fields in superconducting radio-frequency cavities: a review of theoretical aspects
Aug 2017
Presentation Award, the 14th Annual Meeting of PASJ, Sapporo, Japan (Aug.3, 2017)
 
Physics of superconducting cavity: towards realization of high-Q and high gradient
Sep 2013
Young Scientists Best Poster Award, SRF2013, Paris, France (Sep.27, 2013)
 
RF electromagnetic field and vortex penetration in multilayered superconductors

Research Grants & Projects

 
Japan Society for the Promotion of Science (JSPS) Fund for the Promotion of Joint International Research (Fostering Joint International Research) No. 17KK0100
Project Year: Aug 2018 - Mar 2021
Japan Society for the Promotion of Science (JSPS) Grant-in-Aid for Young Scientists (A) No.17H04839
Project Year: Apr 2017 - Mar 2021
CASIO Science Promotion Foundation 34th Research grant No.22
Project Year: Dec 2016 - Nov 2017
Japan Society for the Promotion of Science (JSPS) Grant-in-Aid for Young Scientists (B) No.26800157
Project Year: Apr 2014 - Mar 2017

Published Papers

 
Superconductor Science and Technology   30, 023001   2017   [Refereed][Invited]
*Chosen for Highlights of 2017
Progress of Theoretical and Experimental Physics   2016, 053G01   2016   [Refereed]
Progress of Theoretical and Experimental Physics   2015, 073G01   2015   [Refereed]
Progress of Theoretical and Experimental Physics   2015, 063G01   2015   [Refereed]
Applied Physics Letters   104, 032603   2014   [Refereed]
*Young Scientists Best Poster Award, SRF2013, Paris, France (2013)
Phenomenological consequences in supersymmetric seesaw models
Ph.D. thesis, The Graduate University for Advanced Studies (2010)      [Refereed]
Physics Letters B   687, 349   2010   [Refereed]
Physical Review D   80, 095017   2009   [Refereed]
Physics Letters B   669, 81   2008   [Refereed]
Physics Letters B   666, 262   2008   [Refereed]

Conference Activities & Talks

 
Field-Dependent Nonlinear Surface Resistance and Its Optimization by Surface Nano-Structuring of the SRF Cavities [Invited]
The 19th International Conference on RF Superconductivity, SRF2019, Dresden, Germany (2019)   4 Jul 2019   
* see also Physical Review B 100, 064522 (2019)
The 8th International Workshop on Thin Films and New Ideas for Pushing the Limits of RF Superconductivity, INFN, Italy (2018)   Oct 2018   
* see also Physical Review B 100, 064522 (2019)
Comments on Niobium RRR and SRF cavity performance for ILC [Invited]
TESLA Technology Collaboration (TTC) meeting, RIKEN Nishina Center, Japan (2018)   27 Jun 2018   
Surface impedance and optimum surface resistance of a superconductor with an imperfect surface [Invited]
TESLA Technology Collaboration (TTC) Topical Workshop, IL, USA (2017)   Nov 2017   
* see also Physical Review B 96, 184515 (2017)
A unified theory of surface resistance and the residual resistance of SRF cavities at low temperatures [Invited]
in proceedings of the 18th International Conference on RF Superconductivity, SRF2017, Lanzhou, China (2017), TUXBA04   Jul 2017   
* see also Physical Review B 96, 184515 (2017)
in proceedings of the International Workshop on Future Linear Colliders (LCWS2016), Morioka, Japan   Dec 2016   
GARD-SRF Roadmap Workshop, IL, USA (2017)   Feb 2017   
TESLA Technology Collaboration (TTC) meeting, Saclay, France (2016)   Jul 2016   
* see also Supercond. Sci. Technol. 30, 023001 (2017).
in proceedings of the 7th International Particle Accelerator Conference, IPAC16, Busan, Korea (2016), p. 2164, WEPMB019.   May 2016   
in proceedings of the 7th International Particle Accelerator Conference, IPAC16, Busan, Korea (2016), p. 2161, WEPMB018.   May 2016   
Model to explain the role of thermal gradient in flux expulsion efficiency [Invited]
TESLA Technology Collaboration (TTC) meeting, Menlo Park, CA, USA (2015).   Dec 2015   
* see also Prog. Theor. Exp. Phys. 2016, 053G01 (2016).
in proceedings of the 17th International Conference on RF Superconductivity, SRF 2015, Whistler, Canada (2015), TUBA07   Sep 2015   
* see also Supercond. Sci. Technol. 30, 023001 (2017).
Model of Flux Trapping in Cooling Down Process
in proceedings of the 17th International Conference on RF Superconductivity, SRF 2015, Whistler, Canada (2015), p. 90, MOPB009   Sep 2015   
* see also Prog. Theor. Exp. Phys. 2016, 053G01 (2016).
in proceedings of the 17th International Conference on RF Superconductivity, SRF 2015, Whistler, Canada (2015), p. 86, MOPB008   Sep 2015   
* see also Prog. Theor. Exp. Phys. 2015, 063G01 (2015) and Prog. Theor. Exp. Phys. 2015, 073G01 (2015).
in proceedings of the 6th International Particle Accelerator Conference, IPAC15, Richmond, VA, USA (2015), , p. 2892, WEPMA053.   May 2015   
Field limit and nano-defects covering material surface [Invited]
TESLA Technology Collaboration (TTC) meeting, Tsukuba, Japan (2014).   Dec 2014   
* see also Prog. Theor. Exp. Phys. 2015, 063G01 (2015).
Multipactor simulation of 325MHz superconducting spoke cavity
TESLA Technology Collaboration (TTC) meeting, Tsukuba, Japan (2014).   Dec 2014   
in proceedings of the 27th Linear Accelerator Conference, LINAC14, Geneva, Switzerland (2014), p. 1026, THPP074.   Sep 2014   
* see also Supercond. Sci. Technol. 30, 023001 (2017).
in proceedings of the 27th Linear Accelerator Conference, LINAC14, Geneva, Switzerland (2014), p. 590, TUPP071.   Sep 2014   
* see also Prog. Theor. Exp. Phys. 2015, 063G01 (2015).
in proceedings of the 27th Linear Accelerator Conference, LINAC14, Geneva, Switzerland (2014), p. 1030, THPP075.   Sep 2014   
Two-dimensional models of the magnetic-field enhancement at pit and bumps
in proceedings of the 5th International Particle Accelerator Conference, IPAC14, Dresden, Germany (2014), p. 2525, WEPRI024   May 2014   
* see also Prog. Theor. Exp. Phys. 2015, 073G01 (2015).
Review of the multilayer coating model
in proceedings of the 5th International Particle Accelerator Conference, IPAC14, Dresden, Germany (2014), p. 2522, WEPRI023   May 2014   
* see also Appl. Phys. Lett. 104, 032603 (2014); Supercond. Sci. Technol. 30, 023001 (2017).
in proceedings of the 5th International Particle Accelerator Conference, IPAC14, Dresden, Germany (2014), p. 2519, WEPRI022   May 2014   
Models of the magnetic field enhancement at pits
in proceedings of the 16th International Conference on RF Superconductivity, SRF 2013, Paris, France (2013), p. 433, TUP008   Sep 2013   
* see also Prog. Theor. Exp. Phys. 2015, 073G01 (2015).
Vortex penetration field of the multilayer coating model
in proceedings of the 16th International Conference on RF Superconductivity, SRF 2013, Paris, France (2013), p.430, TUP007   Sep 2013   
* see also Appl. Phys. Lett. 104, 032603 (2014); Supercond. Sci. Technol. 30, 023001 (2017).
in proceedings of the 16th International Conference on RF Superconductivity, SRF 2013, Paris, France (2013), p. 424, TUIOC06   Sep 2013   
RF Field-Attenuation Formulae for the Multilayer Coating Model
in proceedings of the 4th International Particle Accelerator Conference, IPAC13, Shanghai, China (2013), p. 2343, WEPWO014   May 2013   
* see also Appl. Phys. Lett. 104, 032603 (2014); Supercond. Sci. Technol. 30, 023001 (2017).
in proceedings of the 4th International Particle Accelerator Conference, IPAC13, Shanghai, China (2013), p. 2346, WEPWO015   May 2013   
Parameter search of EBW condition for high gradient application
TESLA Technology Collaboration Meeting, Newport News, VA, USA (2012)   Nov 2012   
KEK Theory Meeting on Particle Physics Phenomenology, KEK-PH2010, Ibaraki, Japan (2010)   2010   
* see also Phys. Lett. B 687, 349 (2010).
in proceedings of the 16th International Conference on Supersymmetry and Unification of Fundamental Interactions, SUSY08, Seoul, Korea (2008), AIP Conf. Proc. 1078, 402 (2008)   2008   
* see also Phys. Lett. B 666, 262 (2008).

Teaching Experience

 
 

Misc

 
超伝導加速空洞の物理:高Q値・高加速勾配空洞の実現に向けて
第14回 日本加速器学会年会      Aug 2017   [Invited]
超伝導空洞研究の現状: high-Q0及びhigh-Eaccに向けての取り組みについて
先端加速器科学技術推進協議会(AAA)第12回Green ILC Working Group Meeting, 秋葉原UDX (2016)      Jun 2016   [Invited]
高Q値超伝導加速空洞の研究
先端加速器科学技術推進協議会(AAA)第39回技術部会および第27回大型プロジェクト研究部会合同部会, アルカディア市ヶ谷 (2014)      Nov 2014   [Invited]