{"sections":[{"heading":"Start with an explicit model","paragraphs":["Specify the model-card critical current explicitly when reproducing a circuit. Historical releases have used different defaults, so copying an old explanation's default into a current calculation can change the model.","The maintained reference documents effective area scaling: critical current and capacitance scale with area, while normal resistance scales inversely. An instance critical-current specification can determine that effective scale relative to the model card."]},{"heading":"Check the intended physics","paragraphs":["Record model and instance settings together, including area, IC, RN, capacitance and RTYPE where applicable. Do not assume that specifying an instance IC leaves all other effective device parameters unchanged.","Validate a small junction circuit before interpreting differences in a larger network. Detailed RTYPE/subgap and temperature behaviour still need the matching model reference."]}],"canonical_url":"https://www.sun-magnetics.com/knowledge-base/josim-instance-scaling","url":"/knowledge-base/josim-instance-scaling","known_issues":[],"search_record":{"execution":false,"relatedProducts":[],"version_tags":["JoSIM-Pro 2.9 target"],"text":"Does setting a junction's instance IC change its other parameters? Check the model-card critical current and effective instance area. Instance IC can select a scale factor rather than changing only one isolated value. JoSIM-Pro 2.9.0 release target; review-build/source evidence Explanation Start with an explicit model Specify the model-card critical current explicitly when reproducing a circuit. Historical releases have used different defaults, so copying an old explanation's default into a current calculation can change the model. The maintained reference documents effective area scaling: critical current and capacitance scale with area, while normal resistance scales inversely. An instance critical-current specification can determine that effective scale relative to the model card.  Check the intended physics Record model and instance settings together, including area, IC, RN, capacitance and RTYPE where applicable. Do not assume that specifying an instance IC leaves all other effective device parameters unchanged. Validate a small junction circuit before interpreting differences in a larger network. Detailed RTYPE/subgap and temperature behaviour still need the matching model reference. ","id":"josim-instance-scaling","keywords":"","kind":"Explanation","title":"Does setting a junction's instance IC change its other parameters?","product":"JoSIM-Pro"},"version":"2.9.0 release target; review-build/source evidence","id":"josim-instance-scaling","related":["/knowledge-base/josim-model-syntax","/knowledge-base/josim-junction-resistance"],"downloads":[],"publication_status":"published","numerical_output":null,"provenance":{"execution_checks":[],"figure_evidence":[],"review_notes":["The owner accepted the modelling explanation on 2 November 2026. Applicable release/platform and unrecorded walkthrough checks remain pending."],"scope":"Recorded inputs/builds only. Complete walkthrough and final-package acceptance remain separate.","verification_requirements":{"gui_method":"not-required-for-this-answer","status":"review-incomplete","illustrations":"not-required-for-this-answer","required":["technical-review","release-applicability"],"legacy_walkthrough_field":"pending retained; not evidence of a complete scenario"},"sources":[{"id":"support:SUP-022","section":"Historical junction scaling explanation"},{"id":"josim-pro:docs/manual_source/sections/syntax.tex","section":"Josephson junction parameters and area scaling"},{"id":"owner:technical-review-20261102","section":"JoSIM-Pro 2.9 chosen as the public starting path; release availability must be checked before publication"}]},"title":"Does setting a junction's instance IC change its other parameters?","type":"Explanation","markdown_url":"/_functions/kbResource?path=markdown%2Fjosim-instance-scaling.md","summary":"Check the model-card critical current and effective instance area. Instance IC can select a scale factor rather than changing only one isolated value.","product":"JoSIM-Pro"}