SRF2013 - List of Authors (Joshi, S.C.)

Paper

Title

Page

New Technique and Result of Laser Welded SCRF Cavity Developed at RRCAT

186

P. Khare, R. Arya, J. Dwivedi, R. Ghosh, G. Gilankar, C. Gupta, P.D. Gupta, A. Jain, S.C. Joshi, G.V. Kane, R. Kaul, P.K. Kush, G. Mundra, S.M. Oak, C.K. Pithawa, P. Ram Sankar, S.B. Roy, V.C. Sahni, R.S. Sandha, P. Shrivastava, B.N. Upadhyay
RRCAT, Indore (M.P.), India
C.A. Cooper, C.M. Ginsburg, A. Grassellino, C.S. Mishra, A.M. Rowe
Fermilab, Batavia, USA

A new technique to fabricate SCRF cavities with the help of laser welding process has been developed at Raja Ramanna Centre for Advanced Technology RRCAT), Indore, Department of Atomic Energy, India. In this technique, a pulsed Nd:YAG laser has been used and welding was performed in inert gas environment, in a specially designed welding rig. The advantages of this technique are reduced cost, small heat affected zone, no necessity to weld in vacuum and enhanced rate of production. The paper describes the technique and fabrication method of a single-cell 1.3 GHz SCRF cavity which was fabricated at RRCAT with this new technique. It also discusses the test result of this cavity which was processed and tested at Fermilab. The cavity reached an Eacc of 17MV/m with a Q0 of 1.4 E +10 at 2K. The cavity is being barrel polished for further improvement.

TUIOB01

R&D Progress in SRF Surface Preparation With Centrifugal Barrel Polishing (CBP) for both Nb and Cu

398

A.D. Palczewski
JLAB, Newport News, Virginia, USA
B. Bullock
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
C.A. Cooper
Fermilab, Batavia, USA
S.C. Joshi
RRCAT, Indore (M.P.), India
A. Navitski
DESY, Hamburg, Germany
A.A. Rossi
INFN/LNL, Legnaro (PD), Italy

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
Centrifugal Barrel polishing (CBP) is becoming a common R&D tool for SRF cavity preparation around the word. During the CBP process a cylindrically symmetric SRF cavity is filled with relatively cheap and environmentally friendly abrasive and sealed. The cavity is then spun around the cylindrical axis at high speeds uniformly conditioning the inner surface. This uniformity is especially relevant for SRF application because many times a single manufacturing defects limits cavity’s performance well below it’s theoretical limit. In addition CBP has created surfaces with roughness’s on the order of 10’s of nm which create a unique surface for wet chemistry or thin film deposition. CBP is now being utilized at Jefferson Laboratory, Fermi Laboratory and Cornell University in the US, Ko Enerugi Kasokuki Kenkyu Kiku in Japan, Deutsches Elektronen-Synchrotron in Germany, Laboratori Nazionali di Legnaro in Italy, and Raja Ramanna Centre for Advanced Technology in India. In this talk we will present current CBP research from each lab including polishing recipes, equipment, post CBP chemistry/heat treatment, and subsequent cryogenic cavity tests on niobium as well as copper cavities.

Slides TUIOB01 [2.204 MB]

Paper	Title	Page
MOP036	New Technique and Result of Laser Welded SCRF Cavity Developed at RRCAT	186
	P. Khare, R. Arya, J. Dwivedi, R. Ghosh, G. Gilankar, C. Gupta, P.D. Gupta, A. Jain, S.C. Joshi, G.V. Kane, R. Kaul, P.K. Kush, G. Mundra, S.M. Oak, C.K. Pithawa, P. Ram Sankar, S.B. Roy, V.C. Sahni, R.S. Sandha, P. Shrivastava, B.N. Upadhyay RRCAT, Indore (M.P.), India C.A. Cooper, C.M. Ginsburg, A. Grassellino, C.S. Mishra, A.M. Rowe Fermilab, Batavia, USA
	A new technique to fabricate SCRF cavities with the help of laser welding process has been developed at Raja Ramanna Centre for Advanced Technology RRCAT), Indore, Department of Atomic Energy, India. In this technique, a pulsed Nd:YAG laser has been used and welding was performed in inert gas environment, in a specially designed welding rig. The advantages of this technique are reduced cost, small heat affected zone, no necessity to weld in vacuum and enhanced rate of production. The paper describes the technique and fabrication method of a single-cell 1.3 GHz SCRF cavity which was fabricated at RRCAT with this new technique. It also discusses the test result of this cavity which was processed and tested at Fermilab. The cavity reached an Eacc of 17MV/m with a Q0 of 1.4 E +10 at 2K. The cavity is being barrel polished for further improvement.

TUIOB01	R&D Progress in SRF Surface Preparation With Centrifugal Barrel Polishing (CBP) for both Nb and Cu	398
	A.D. Palczewski JLAB, Newport News, Virginia, USA B. Bullock Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA C.A. Cooper Fermilab, Batavia, USA S.C. Joshi RRCAT, Indore (M.P.), India A. Navitski DESY, Hamburg, Germany A.A. Rossi INFN/LNL, Legnaro (PD), Italy
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. Centrifugal Barrel polishing (CBP) is becoming a common R&D tool for SRF cavity preparation around the word. During the CBP process a cylindrically symmetric SRF cavity is filled with relatively cheap and environmentally friendly abrasive and sealed. The cavity is then spun around the cylindrical axis at high speeds uniformly conditioning the inner surface. This uniformity is especially relevant for SRF application because many times a single manufacturing defects limits cavity’s performance well below it’s theoretical limit. In addition CBP has created surfaces with roughness’s on the order of 10’s of nm which create a unique surface for wet chemistry or thin film deposition. CBP is now being utilized at Jefferson Laboratory, Fermi Laboratory and Cornell University in the US, Ko Enerugi Kasokuki Kenkyu Kiku in Japan, Deutsches Elektronen-Synchrotron in Germany, Laboratori Nazionali di Legnaro in Italy, and Raja Ramanna Centre for Advanced Technology in India. In this talk we will present current CBP research from each lab including polishing recipes, equipment, post CBP chemistry/heat treatment, and subsequent cryogenic cavity tests on niobium as well as copper cavities.
	Slides TUIOB01 [2.204 MB]