CS195083B1 - Method of stabilization of the supraconductive diffusing nb3sn bands - Google Patents

Description

SOCIALISTIC AND DESCRIPTION OF THE INVENTION

TO 195083 (11) (Bl)

(51) Int. C1.3H 01 B 12/00 / 22 / Registered 11 07 77/21 / / PV 4591-77 / (40) Published 28 04 79

OFFICE OFFICE (45) Published 1 5 04 82

AND DISCOVERY (75)

Author of the invention POLÁK MILAN ing., HLÁSNIK IVAN ing., ŠABO MARIÁN ing.

and OKÁLI DANIEL ing., BRATISLAVA (54) Method of stabilization of superconducting diffuse Nb3Sn tapes x

BACKGROUND OF THE INVENTION The present invention relates to superconducting diffusion bands and solves the reduction of the transition electrical resistance between the stabilizing layer of the medium and the superconducting layer of Nb3, and the simultaneous increase in mechanical consistency between the stabilizing layer and the conductive layer.

The superconducting diffusion Nb3Sn tape stabilizing system currently used requires that a sufficient amount of tin be deposited on the surface of the superconducting tape to which the cyanide solution is applied by electrolytic treatment of the intermediate layer and the next, sufficiently thick layer is applied electrolytically using the acidic solutions. stabilizing metal, usually medium. Another method, requiring also a loose tin on the surface of the superconducting tape, consists in plating superconductors with copper diphthiamines.

Currently, the NbjSn superconducting tapes do not have a sufficiently smooth surface and the copper stabilizing layer formed directly electrolytically follows the three-dimensional properties, which is unsuitable for their further use. Similar problems are caused by sostabilization produced by cladding, whereby, as a result, a uniform, several microns coarse interlayer is to be formed prior to cladding.

The drawbacks of the prior art are to eliminate the problem of the present invention, which consists in the fact that in stabilization! superconducting NbgSn tapes with electrolytically formed media layer are first etched away from tin or bronze found on the surface of the strip after the diffusion process, e.g. with HCl, HCl + + HNO3 or other suitable etchant, then the tape is electrolytically crosslinked with an alkali-conducting line. solution, advantageous through the mediation solution formed from the Seignette salt, NaOH and CUSO 4, so that a thickness of at least 1 µm is reached, thereby achieving a transition resistance of at most 6.10 µm Ohm between the superconducting layer and the copper stabilizing layer and then at copper electrolytic solution (preferred in the CUSO4 solution in H2SO4Z) is a copper stabilizing layer.

Removing the intermediate layer from the poorly conductive target, resp. bronze reduces the thickness of the tape without reducing its critical current. Thus, the resulting thickness of the stabilized tape is the thickness of the etched non-effective intermediate layer, thereby actually increasing the mean critical current density in the cross-section of the stabilized tape. In the superconducting stabilized Nb3Sn strips, the current resistivity of Rp / 1 is 1 cm < 2 > between the solids layer and the copper stabilizing layer in the range of 1 to 2 " In the case of belts stabilized by the technology according to the invention, this transition resistance can be reduced by as much as one order of magnitude to 6-8.10 "“ Ohm.

By increasing the mechanical cohesion of the superconducting layer and the stabilizing copper layer, it increases the tape's resistance to damage. The effect of the invention is to achieve a reduction in the transition resistance of 1 cm @ 2 of contact area between the superconducting layer and the copper stabilization layer at 6-8.10 @ 9 Ohm, 195083.

Claims (1)

195083 The ratio of the stabilization layer resistances to 300 K and 4.2 K is in the range. 60-70, increasing the mechanical retention of the superconducting layer and the stabilizing layer of the medium such that a min. Force of at least 2 mm is required to tear the copper layer from the superconductive layer on a 2 mm wide tape sample. 4,5 kp. EXAMPLE A superconducting diffusion Nb3Sn tape is immersed in dilute HCl / HCl, H2O = 2: 1 and leptase 5-20 min. After rinsing in water and drying the air, the tape is immersed in the mediation (PR / ED-ET) method of stabilizing the superconducting diffuse Nb3Sn tapes with an electrolytically formed copper layer, indicating the tin or bronze residue found in the sapo diffusion process on the superconducting Nb3 layer. etching with, for example, HCl, HCl + + HNO 3, or other suitable etchant, the superconducting tape is electrolytically eluted through an alkaline solution, preferably through a flow formed from a Seignett salt 150 g / l, NaOH 80 g / l, CuS 4 O 5 H 2 O 30 g / l, with a volume of 1 liter being distilled with water. Electrolysis takes place at a density of 0.5-1.5 A / dm @ 2. After removing the tape from this electrolyte and drying the tape, it is immersed in the acidic electrolyte, which is composed of 250 g of CUSO4.5H2O, 11 cm3H2SO4, 10 cm @ 3 of alcohol and a residual volume of 1 liter of distilled water. The electrolytic conversion of this solution takes place at a current density of 1-5 A / cm @ 2. The use of the invention is contemplated in the production of superconducts. DISCLOSURE OF THE INVENTION A mediation solution formed from Seignett's salt, NaOH and CUSO 4, such that a copper layer thickness of at least 1 µm is achieved, whereby a transition resistance of at most 6.10 9 9 ohms between the superconducting layer and the copper stabilizer starts with the layer and then a copper stabilizing layer is preferably formed electrolytically in an acidic media solution (preferably in a CUSO 4 in H 2 SO 4 solution). Severografia. n. p., race 7. Sinal