| The discovery of high temperature superconductors（HTS）has accelerated the development of superconducting technology.（Bi,Pb）2Sr2Ca2Cu3O10（Bi-2223）HTS tape is one of the high temperature superconducting wires for commercial applications recently.Its superconducting critical transition temperature is 105-110 K.The Bi-2223tape has a large superconducting temperature range,which is above the liquid nitrogen vaporization temperature（77 K）.Critical current is one of the important indexes to evaluate the performance and practical value of superconducting tape.So far,domestic and foreign researches focused deeply onto the Bi-2223 HTS tape and the device made of it,but systematic experimental data on the critical current characteristics of the tape in the zone above liquid nitrogen temperature are still lacking.With the development of technology,some applications require Bi-2223 HTS tape and its products working at the temperature zone above liquid nitrogen temperature.Therefore,it is urgent to study the flow capacity of Bi-2223 superconducting tape in the temperature zone above liquid nitrogen temperature to fill this research gap.In response to this requirement,we have carried out several relevant researches.The results indicate that the Bi-2223 tape can still carry the superconducting current with practical significance at the temperature range above 77 K.At 92 K,when there is no external magnetic field,or the external magnetic field is nearly parallel to the HTS tape surface and weaker than 0.1 T,the critical current can still maintain 40-50%of its value of the condition with 77 K and self-field.Three kinds of Bi-2223 HTS tapes were selected as experimental samples for the measurements of their critical current in the temperature range of 77-92 K,the applied magnetic field intensity range of 0-0.2 T,and the magnetic field angle range of 0-90°systematically,the measured results were analyzed and summarized.This paper provides the critical current data of Bi-2223 superconducting tape under the above conditions.The research results have certain reference value for the selection of materials for the design of various superconductive devices in the future. |
