NAPAC2019 - List of Keywords (niobium)

Paper	Title	Other Keywords	Page
MOPLS09	Engineering Design of Gallium-Nickel Target in Niobium Capsule, with a Major Focus on Determining the Thermal Properties of Gallium-Nickel Through Thermal Testing and FEA, for Irradiation at BLIP	target, radiation, proton, experiment	170
	S.K. Nayak, S. Bellavia, H. Chelminski, C.S. Cutler, D. Kim, D. Medvedev BNL, Upton, New York, USA
	Funding: Funding:This abstract is authored by BSA operated under contract number DE-SC0012704. This research is supported by the U.S. DOE Isotope Program, managed by the Office of Science for Nuclear Physics. The Brookhaven Linac Isotope Producer (BLIP) produces several radioisotopes using a variable energy and current proton beam. The targets irradiated at BLIP are cooled by water and required to be isolated in a target capsule. During the design stage, thermal analysis of the target and cladding is carried out to determine the maximum beam power a target can handle during irradiation without destruction. In this work we designed a capsule for Gallium-Nickel (Ga 80%, Ni 20%) alloy target material and irradiated the target at the BLIP to produce the radioisotope Ge-68. Since no literature data is available on Ga4Ni’s thermal conductivity (K) and specific heat (C), measurements were carried out using thermal testing in conjunction with Finite Element Analysis (FEA). Steady-state one dimensional heat conduction method was used to determine the thermal conductivity. Transient method was used to calculate the specific heat. The test setup with same methodologies can be used to assess other targets in the future. Here, we will detail these studies and discuss the improved design and fabrication of this target.
	Poster MOPLS09 [0.751 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-MOPLS09
About •	paper received ※ 27 August 2019 paper accepted ※ 03 September 2019 issue date ※ 08 October 2019
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MOPLH10	Field-Emission Electron Source Embedded in a Field-Enhanced Conduction-Cooled Superconducting RF Cavity	cavity, electron, cathode, experiment	192
	D. Mihalcea, V. Korampally, A. McKeown, O. Mohsen, P. Piot, I. Salehinia Northern Illinois University, DeKalb, Illinois, USA R. Dhuley, M.G. Geelhoed, P. Piot, J.C.T. Thangaraj Fermilab, Batavia, Illinois, USA
	We present simulations and experimental progress toward the development of a high-current electron source with the potential to deliver high charge electron bunches at GHz-level repetition rates. To achieve these goals electrons are generated through field-emission and the cathode is immersed in a conduction-cooled superconducting 650-MHz RF cavity. The field-emitters consist of microscopic silicon pyramids and have a typical enhancement factor of about 500. To trigger field-emission, the peak field inside the RF cavity of about 6 MV/m is further enhanced by placing the field-emitters on the top of a superconducting Nb rod inserted in the RF cavity. So far, we cannot control the duration of the electron bunches which is of the order of RF period. Also, the present cryo-cooler power of about 2 W limits the beam current to microamp level.
	Poster MOPLH10 [1.063 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-MOPLH10
About •	paper received ※ 27 August 2019 paper accepted ※ 05 September 2019 issue date ※ 08 October 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPLM47	Analysis of High Field Q-Slope (HFQS) Causes and Development of New Chemical Polishing Acid	cavity, SRF, experiment, superconductivity	699
	D. Luo, E.S. Metzgar, L. Popielarski, K. Saito, S.M. Shanab, G.V. Simpson FRIB, East Lansing, Michigan, USA T. Nakajima, I. Nasu, J. Taguchi Nomura Plating Co, Ltd., Osaka, Japan
	Funding: U.S. National Science Foundation under Grant PHY-1565546. In our previous studies of High Field Q-slope (HFQS) we have concluded that nitrogen contamination from the nitric acid is the main cause of the degradation of the Q in buffered chemical polished cavities. Our conclusion is made based on previously unresolved phenomena which are found from huge amount of published cavity test data, include fine grain, large grain and single crystal cavities treated with EP and BCP. According to this analysis, we have started developing new nitrogen-free chemical polishing acid. Hydrogen peroxide with HF mixture was reported able to react with Nb, and there’s no extra element contamination in it, so we replace the conventional BCP with this mixture to start our study. In this paper, some Nb coupon sample results with new acid will be reported. We complete the first step of developing the new acid and we got the Nb finish roughness no worse than conventional BCP.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEPLM47
About •	paper received ※ 13 September 2019 paper accepted ※ 04 December 2019 issue date ※ 08 October 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPLM63	Development of a Secondary Sn Source for Nb₃Sn Coating of Half-Wave Coaxial Resonator	cavity, SRF, MMI, superconductivity	735
	J.K. Tiskumara, J.R. Delayen, H. Park ODU, Norfolk, Virginia, USA G.V. Eremeev JLab, Newport News, Virginia, USA U. Pudasaini The College of William and Mary, Williamsburg, Virginia, USA
	Superconducting thin films have the potential of reducing the cost of particle accelerators. Among the potential materials, Nb₃Sn has a higher critical temperature and higher critical field compared to niobium. Sn vapor diffusion method is the preferred technique to coat niobium cavities. Although there are several thin-film-coated basic cavity models that are tested at their specific frequencies, the Half-wave resonator could provide us data across frequencies of interest for particle accelerators. With its advanced geometry, increased area, increased number of ports and hard to reach areas, the half-wave resonator needs a different coating approach, in particular, a development of a secondary Sn source. We are commissioning a secondary Sn source in the coating system and expand the current coating system at JLab to coat complex cavity models.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEPLM63
About •	paper received ※ 27 August 2019 paper accepted ※ 06 September 2019 issue date ※ 08 October 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

Engineering Design of Gallium-Nickel Target in Niobium Capsule, with a Major Focus on Determining the Thermal Properties of Gallium-Nickel Through Thermal Testing and FEA, for Irradiation at BLIP

target, radiation, proton, experiment

170

S.K. Nayak, S. Bellavia, H. Chelminski, C.S. Cutler, D. Kim, D. Medvedev
BNL, Upton, New York, USA

Funding: Funding:This abstract is authored by BSA operated under contract number DE-SC0012704. This research is supported by the U.S. DOE Isotope Program, managed by the Office of Science for Nuclear Physics.
The Brookhaven Linac Isotope Producer (BLIP) produces several radioisotopes using a variable energy and current proton beam. The targets irradiated at BLIP are cooled by water and required to be isolated in a target capsule. During the design stage, thermal analysis of the target and cladding is carried out to determine the maximum beam power a target can handle during irradiation without destruction. In this work we designed a capsule for Gallium-Nickel (Ga 80%, Ni 20%) alloy target material and irradiated the target at the BLIP to produce the radioisotope Ge-68. Since no literature data is available on Ga4Ni’s thermal conductivity (K) and specific heat (C), measurements were carried out using thermal testing in conjunction with Finite Element Analysis (FEA). Steady-state one dimensional heat conduction method was used to determine the thermal conductivity. Transient method was used to calculate the specific heat. The test setup with same methodologies can be used to assess other targets in the future. Here, we will detail these studies and discuss the improved design and fabrication of this target.

Poster MOPLS09 [0.751 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-MOPLS09

About •

paper received ※ 27 August 2019 paper accepted ※ 03 September 2019 issue date ※ 08 October 2019

Export •

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

MOPLH10

Field-Emission Electron Source Embedded in a Field-Enhanced Conduction-Cooled Superconducting RF Cavity

cavity, electron, cathode, experiment

192

D. Mihalcea, V. Korampally, A. McKeown, O. Mohsen, P. Piot, I. Salehinia
Northern Illinois University, DeKalb, Illinois, USA
R. Dhuley, M.G. Geelhoed, P. Piot, J.C.T. Thangaraj
Fermilab, Batavia, Illinois, USA

We present simulations and experimental progress toward the development of a high-current electron source with the potential to deliver high charge electron bunches at GHz-level repetition rates. To achieve these goals electrons are generated through field-emission and the cathode is immersed in a conduction-cooled superconducting 650-MHz RF cavity. The field-emitters consist of microscopic silicon pyramids and have a typical enhancement factor of about 500. To trigger field-emission, the peak field inside the RF cavity of about 6 MV/m is further enhanced by placing the field-emitters on the top of a superconducting Nb rod inserted in the RF cavity. So far, we cannot control the duration of the electron bunches which is of the order of RF period. Also, the present cryo-cooler power of about 2 W limits the beam current to microamp level.

Poster MOPLH10 [1.063 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-MOPLH10

About •

paper received ※ 27 August 2019 paper accepted ※ 05 September 2019 issue date ※ 08 October 2019

Export •

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

WEPLM47

Analysis of High Field Q-Slope (HFQS) Causes and Development of New Chemical Polishing Acid

cavity, SRF, experiment, superconductivity

699

D. Luo, E.S. Metzgar, L. Popielarski, K. Saito, S.M. Shanab, G.V. Simpson
FRIB, East Lansing, Michigan, USA
T. Nakajima, I. Nasu, J. Taguchi
Nomura Plating Co, Ltd., Osaka, Japan

Funding: U.S. National Science Foundation under Grant PHY-1565546.
In our previous studies of High Field Q-slope (HFQS) we have concluded that nitrogen contamination from the nitric acid is the main cause of the degradation of the Q in buffered chemical polished cavities. Our conclusion is made based on previously unresolved phenomena which are found from huge amount of published cavity test data, include fine grain, large grain and single crystal cavities treated with EP and BCP. According to this analysis, we have started developing new nitrogen-free chemical polishing acid. Hydrogen peroxide with HF mixture was reported able to react with Nb, and there’s no extra element contamination in it, so we replace the conventional BCP with this mixture to start our study. In this paper, some Nb coupon sample results with new acid will be reported. We complete the first step of developing the new acid and we got the Nb finish roughness no worse than conventional BCP.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEPLM47

About •

paper received ※ 13 September 2019 paper accepted ※ 04 December 2019 issue date ※ 08 October 2019

Export •

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

WEPLM63

Development of a Secondary Sn Source for Nb₃Sn Coating of Half-Wave Coaxial Resonator

cavity, SRF, MMI, superconductivity

735

J.K. Tiskumara, J.R. Delayen, H. Park
ODU, Norfolk, Virginia, USA
G.V. Eremeev
JLab, Newport News, Virginia, USA
U. Pudasaini
The College of William and Mary, Williamsburg, Virginia, USA

Superconducting thin films have the potential of reducing the cost of particle accelerators. Among the potential materials, Nb₃Sn has a higher critical temperature and higher critical field compared to niobium. Sn vapor diffusion method is the preferred technique to coat niobium cavities. Although there are several thin-film-coated basic cavity models that are tested at their specific frequencies, the Half-wave resonator could provide us data across frequencies of interest for particle accelerators. With its advanced geometry, increased area, increased number of ports and hard to reach areas, the half-wave resonator needs a different coating approach, in particular, a development of a secondary Sn source. We are commissioning a secondary Sn source in the coating system and expand the current coating system at JLab to coat complex cavity models.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2019-WEPLM63

About •

paper received ※ 27 August 2019 paper accepted ※ 06 September 2019 issue date ※ 08 October 2019

Export •

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