Correlation Between the Number of Displacements Per Atom and After High-Energy Irradiations of Nb<sub>3</sub>Sn Wires for the HL-LHC

Spina, Tiziana; Scheuerlein, C.; Richter, David H.; Ballarino, A.; Cerutti, F.; Esposito, L. S.; Lechner, Anton; Bottura, L.; Flükiger, R.

doi:10.1109/tasc.2016.2549858

Cited by 7 publications

(17 citation statements)

References 13 publications

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“…We conclude that improvements of Jc properties in the >16 T range at 4.2 K are still possible, also perhaps by using longer and higher HT temperatures to make the layers more compositionally uniform (recognizing of course that more effective diffusion barriers must be provided to protect the outer stabilizing Cu too). Although high field Jc can also be enhanced by increasing the density and effectiveness of flux pinning sites by decreasing the grain size, adding pinning centers 25,26 or introducing point pinning by irradiation, 27,28 these techniques do not raise Hc2. Thus, consideration of these surprising site disorder results should also be incorporated into any enhanced pinning center approach in order to raise the high field Jc.…”

Section: Calculations)mentioning

confidence: 99%

Evidence from EXAFS for Different Ta/Ti Site Occupancy in High Critical Current Density Nb3Sn Superconductor Wires

Heald

Tarantini

Lee

et al. 2018

Sci Rep

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To meet critical current density, Jc, targets for the Future Circular Collider (FCC), the planned replacement for the Large Hadron Collider (LHC), the high field performance of Nb3Sn must be improved, but champion Jc values have remained static for the last 10 years. Making the A15 phase stoichiometric and enhancing the upper critical field Hc2 by Ti or Ta dopants are the standard strategies for enhancing high field performance but detailed recent studies show that even the best modern wires have broad composition ranges. To assess whether further improvement might be possible, we employed Extended X-ray Absorption Fine Structure (EXAFS) to determine the lattice site location of dopants in modern high-performance Nb3Sn strands with Jc values amongst the best so far achieved. Although Ti and Ta primarily occupy the Nb sites in the A15 structure, we also find significant Ta occupancy on the Sn site. These findings indicate that the best performing Ti-doped stand is strongly sub-stoichiometric in Sn and that antisite disorder likely explains its high average Hc2 behavior. These new results suggest an important role for dopant and antisite disorder in minimizing superconducting property distributions and maximizing high field Jc properties.

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Section: Calculations)mentioning

confidence: 99%

Evidence from EXAFS for Different Ta/Ti Site Occupancy in High Critical Current Density Nb3Sn Superconductor Wires

Heald

Tarantini

Lee

et al. 2018

Sci Rep

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“…A significantly smaller decrease rate was found in Nb 3 Sn (0.35 × 10 −22 Km 2 ) [13], which is a fully gaped superconductor and a decrease in the electronic DOS at the Fermi level is responsible in that case. However, although a comparison of the changes induced by a particular radiation is useful for testing the suitability of a certain material in the respective environment (fusion [10,62] or accelerator magnets [14,65,66]), it is a bit problematic for a comparison of the material's sensitivity to disorder for drawing conclusions on the underlying mechanisms, since the introduced disorder itself depends on the material. The number of displacements per atom (dpa) is a more suitable measure for this purpose, although the morphology of the defects is expected to be important as well with single displaced atoms being the most efficient scattering centers and hence reducing the transition temperature the most at a given dpa.…”

Section: Transition Temperaturementioning

confidence: 99%

“…Granularity effects can be studied by tuning the ratio between the currents flowing within the grains and the currents crossing grain boundaries [7][8][9]. Finally, irradiation experiments have been also carried out to test the suitability of a conductor for operation in a radiation environment, such as fusion [10][11][12] or accelerator magnets [13,14]. The aim of this topical review is to summarize these different kinds of irradiation experiments on iron-based superconductors and compare them with other superconducting materials.…”

Section: Introductionmentioning

confidence: 99%

Radiation effects on iron-based superconductors

Eisterer

2017

Supercond. Sci. Technol.

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This article reviews the results of irradiation experiments on iron-based superconductors, with particular emphasis on neutron irradiation. These experiments were either done to foster the theoretical understanding of superconductivity in these compounds by investigating the influence of impurity scattering on the fundamental superconducting properties or to investigate vortex physics and to benchmark flux pinning in view of applications. Results on the most explored iron-based compounds are summarized and compared with data on metallic superconductors, cuprates, and MgB 2 . Similarities and differences are discussed as well as the influence of the type and energy of the particles used for the experiments.

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“…When the thickness is less than 1 µm, the detailed distribution of damage energy should be taken into consideration. e density of YBCO layer is 6.54 g/cm 3 . In the calculation, the incident neutrons are monoenergetic and the direction is shown in Figure 4.…”

Section: Displacement Damage Calculationmentioning

confidence: 99%

“…In the irradiation effect study on superconducting materials, DPA number has been used to predict the properties change of material [1,2]. ere is evidence that DPA can be used to correlate the radiation effect, such as the change of the critical current and the critical temperature of superconductors, under different irradiation particles [3]. In the study of ion irradiation effects on the Yttrium Barium Copper Oxide (YBCO) high temperature superconducting films or tapes, SRIM [4] is commonly used to calculate DPA [5][6][7][8].…”

Section: Introductionmentioning

confidence: 99%

Study on the Applicability of Neutron Radiation Damage Method Used for High-Temperature Superconducting Tape Based on Geant4 and SRIM

Zheng

Wang

2021

Science and Technology of Nuclear Installations

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High-temperature superconducting material is a promising candidate to fabricate superconducting magnet for magnetic confinement fusion reactors. The DPA number of the 1 µm thick superconducting layer in a high temperature superconducting tape under neutron irradiation needs to be calculated to predict the property changes. The DPA cross sections, which ignore the spatial distribution of vacancies caused by PKAs, are commonly used to obtain the results of the damage energy and DPA. However, for geometric models with the thickness as small as 1 µm, the energy and angular distribution of PKAs reveal that a significant number of PKAs with relatively high energy tend to scatter forward and cross the boundary of model, so the thickness of model has the potential to affect the number of displaced atoms. In this paper, we developed a method based on Geant4 and SRIM to evaluate the deviation of the traditional analytic method caused by the thickness. Geant4 is used to obtain the location, direction, and energy of PKAs, while SRIM is used to track every PKA and obtain damage energy and the number of displaced atoms. The radiation damage calculation of simple thin plate models with different thicknesses and the tape model are conducted with the neutron energies from 1 to 14 MeV. The results show that PKAs need to be tracked continuously for models with thickness less than 10 µm and the deviation of the analytic formulas increases rapidly with the decrease of thickness. For the superconducting layer composed of four different elements in the tape, the deviation also depends on the proportion of each atomic species and the neutron-atom interaction cross sections under different incident neutron energy.

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Correlation Between the Number of Displacements Per Atom and After High-Energy Irradiations of Nb₃Sn Wires for the HL-LHC

Cited by 7 publications

References 13 publications

Evidence from EXAFS for Different Ta/Ti Site Occupancy in High Critical Current Density Nb3Sn Superconductor Wires

Evidence from EXAFS for Different Ta/Ti Site Occupancy in High Critical Current Density Nb3Sn Superconductor Wires

Radiation effects on iron-based superconductors

Study on the Applicability of Neutron Radiation Damage Method Used for High-Temperature Superconducting Tape Based on Geant4 and SRIM

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Correlation Between the Number of Displacements Per Atom and After High-Energy Irradiations of Nb3Sn Wires for the HL-LHC

Cited by 7 publications

References 13 publications

Evidence from EXAFS for Different Ta/Ti Site Occupancy in High Critical Current Density Nb3Sn Superconductor Wires

Evidence from EXAFS for Different Ta/Ti Site Occupancy in High Critical Current Density Nb3Sn Superconductor Wires

Radiation effects on iron-based superconductors

Study on the Applicability of Neutron Radiation Damage Method Used for High-Temperature Superconducting Tape Based on Geant4 and SRIM

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Correlation Between the Number of Displacements Per Atom and After High-Energy Irradiations of Nb₃Sn Wires for the HL-LHC