简介：ExperimentalresultsonthemagneticfieldbehaviorofthecriticalcurrentinsilversheathedBi-2223tapesarepresented.Theexperimentsconsistoftransportandmagneticmeasurementsinawidetemperaturerangeandinexternalmagneticfieldupto6T.SignificantenhancementoftheintragraincriticalcurrentdensitiesJcareobservedafterirradiationwithfastneutron.Thisisattributedtoanimprovementoffluxpinningcapabilitybytheneutroninduceddefects,buttheweaklinkstructureissomewhatdamagedasevidencedbythesmalldegradationoftransportcriticalcurrentatlowfield.Accordingtothemeasurementofremanentmagneticmomentbeforeandafterirradiationwithfastneutron,theconnectivityinBi-2223tapesisreducedby50%afterirradiatedtoafluenceof2×1021m-2,whichresultedinthecriticalcurrentsdegradatedbyafactorof10%.