IEC 61788-23-2024 PDF

Full title and description

St IEC 61788-23-2024 — Superconductivity - Part 23: Residual resistance ratio measurement - Residual resistance ratio of cavity-grade Nb superconductors. This international standard specifies a laboratory test method to determine the residual resistance ratio (rRRR) of high‑purity, cavity‑grade niobium used for superconducting radio‑frequency (SRF) cavities and related applications.

Abstract

IEC 61788-23:2024 provides a method to determine the residual resistance ratio (RRR, rRRR) of cavity‑grade niobium. The procedure is intended for high‑purity niobium grades with rRRR in the approximate range 150 to 600 and is applicable to specimens of specified cross‑section and aspect ratio. The standard includes specimen preparation, measurement procedure, and requirements for reporting results.

General information

• Status: Published — International Standard (IEC TC 90, Superconductivity).
• Publication date: 22 May 2024.
• Publisher: International Electrotechnical Commission (IEC).
• ICS / categories: 17.220; 29.050 (Electrical and magnetic measurements; Conducting materials / superconductivity).
• Edition / version: Edition 3.0 (2024).
• Number of pages: 59 pages.

(Publication metadata and committee information from the IEC public record.)

Scope

This part of IEC 61788 specifies a test method for the determination of the residual resistance ratio (rRRR) of cavity‑grade niobium intended for superconducting cavities. The method applies to high‑purity niobium with rRRR roughly between 150 and 600. It is valid for specimens with rectangular or round cross‑section, a cross‑sectional area greater than 1 mm² but less than 20 mm², and a length between 10 and 25 times the width or diameter. The standard covers specimen preparation, measurement apparatus and conditions, measurement procedure, calculation of rRRR, and reporting requirements.

Key topics and requirements

• Definition and measurement principle for residual resistance ratio (rRRR) of cavity‑grade niobium.
• Applicable rRRR measurement range: nominally 150 < rRRR < 600.
• Permitted specimen geometry: round or rectangular cross‑section; area > 1 mm² and < 20 mm²; length between 10 and 25 times width/diameter.
• Detailed specimen preparation, mounting and electrical contact requirements to ensure accurate low‑temperature resistance measurements.
• Specified measurement apparatus and environmental conditions (cryogenic measurement considerations) and procedures for calculating and reporting rRRR.
• Requirements for test-report content to ensure traceability and repeatability of results.

(Key technical limits and procedural topics summarized from the published standard.)

Typical use and users

This standard is used by materials laboratories, SRF cavity manufacturers, research institutes, cryogenic test facilities, quality assurance and acceptance test groups, and standards bodies involved in superconducting materials characterization. Typical users include material scientists, metallurgists, superconducting cavity engineers, and test laboratory personnel responsible for verifying niobium purity and performance for accelerator and cryogenic applications.

Related standards

IEC 61788 is a multipart series covering superconductivity test methods (other parts include, for example, IEC 61788‑1, IEC 61788‑2, IEC 61788‑3 and additional parts addressing critical current and other superconducting material measurements). IEC 61788‑23 is published under TC 90 (Superconductivity) and should be considered alongside other parts of IEC 61788 when establishing comprehensive test programs for superconducting materials.

Keywords

residual resistance ratio; RRR; rRRR; niobium; cavity-grade Nb; superconductivity; test method; cryogenic measurement; IEC 61788; TC 90.

FAQ

Q: What is this standard?

A: IEC 61788‑23:2024 is an international standard that specifies a laboratory method to measure the residual resistance ratio (rRRR) of cavity‑grade niobium used in superconducting radio‑frequency cavities and related applications.

Q: What does it cover?

A: It covers specimen geometry limits, specimen preparation, measurement apparatus and environmental (cryogenic) considerations, the measurement procedure to obtain rRRR, calculation methods, and required content for test reports. The method is intended for high‑purity niobium with rRRR in the approximate range 150–600 and for specimens within defined size and aspect‑ratio limits.

Q: Who typically uses it?

A: Materials testing laboratories, SRF cavity manufacturers, research institutions, cryogenic test facilities, and QA groups who need to quantify niobium purity and electrical residual resistance at low temperatures for superconducting applications.

Q: Is it current or superseded?

A: IEC 61788‑23:2024 is the current (published) edition as of 22 May 2024. It is published as Edition 3.0 and replaces earlier editions (the document record indicates it revises the 2021 edition). Users should reference the 2024 edition for the latest technical content.

Q: Is it part of a series?

A: Yes — IEC 61788 is a multipart series on superconductivity test methods prepared by IEC TC 90. Part 23 is one of the parts in that series and should be used in conjunction with other relevant IEC 61788 parts when developing test programs for superconducting materials.

Q: What are the key keywords?

A: residual resistance ratio; RRR; niobium; cavity‑grade; superconductivity; cryogenic measurement; test method; IEC 61788; TC 90.