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The Pre-Series Cryoline (PTCL) for ITER is a representative cryoline from the complicated network of all cryolines for the ITER project. It is ~28 m in length with same cross-section (1:1) including main line (ML) and branch line (BL) as of ITER torus & cryostat cryoline. Geometrically; it has bends at different angles i.e. 90°, 120°, 135° & 160° comprising T-section & Z-section. The PTCL has been fabricated in 5 different elements based on the installation feasibility. The mechanical & instrumentation installation like sensors mounting, displacement sensors, etc. has been completed. The PTCL test has been performed after complete installation of PTCL and integration with the existing test facility at ITER-India cryogenics laboratory in order to verify the thermal performance and mechanical integrity. The primary objectives, which are evaluated during the PTCL test, are (i) Thermal performance of the PTCL (ii) Measurement of temperature profile on thermal shield of PTCL, (iii) Stress measurement at critical locations, (iv) Measurement of Outer Vacuum Jacket (OVJ) temperature during Break of Insulation Vacuum (BIV) test. The paper will summarize the methodology and observed results of PTCL.

A two-channel prototype cryogenic temperature transmitter is developed using an ARM Cortex-M3 series precision analog microcontroller using a rapid prototyping method for use in indigenous developments. The developed prototype utilizes an Arduino compatible baseboard equipped with interfaces for programming/debugging. Additional circuits are fabricated, and embedded application software is developed and tested. The input circuit consists of a low-value high accuracy precision current source to excite the cryogenic temperature sensors of Resistance Temperature Detector (RTD) type and employs a standard four-wire ratiometric measurement technique for accurate resistance measurement. The ratiometric measurement eliminates measurement errors due to current uncertainty. The precision microcontroller is equipped with internal programmable gain amplifiers to accurately scale low-level analog signals from cryogenic temperature sensors. The developed transmitter can interface with two cryogenic RTDs (Cernox® and PT-100 types) and can accurately measure resistance over its calibrated range (300–4 K). The cubic spline interpolation method is employed in application software for converting the measured resistance to temperature. The measured temperature is transmitted to a programmable logic device (via 4–20 mA signals) using the pulse width modulation technique. The developed transmitter is tested for its performance against commercially available transmitters at the liquid nitrogen temperature, liquid helium temperature, and over the entire measurement range using Gifford–McMahon type cryocoolers. The developed transmitter was utilized to assess the impact of the thermal resistance of the cryogenic sensors at the lowest temperature of the cryocooler (∼2.6 K). This paper outlines design details, application software development, experimental setup, measurement uncertainties, and test results.

Abstract. Since the conceptual design of the ITER Cryodistribution many modifications have been applied due to both system optimization and improved knowledge of the clients' requirements. Process optimizations in the Cryoplant resulted in component simplifications whereas increased heat load in some of the superconducting magnet systems required more complicated process configuration but also the removal of a cold box was possible due to component arrangement standardization. Another cold box, planned for redundancy, has been removed due to the Tokamak in-Cryostat piping layout modification. In this proceeding we will summarize the present design status and component configuration of the ITER Cryodistribution with all changes implemented which aim at process optimization and simplification as well as operational reliability, stability and flexibility.