Speaker
Description
The IFMIF-DONES facility will be an accelerator driven neutron source, delivering around 10E17 n/s with a spectrum tailing above 40 MeV for the irradiation of structural materials for fusion applications. This study focuses on the testing and evaluation of a current-mode micro ionisation chamber (uIC) with experiments conducted in the Linear IFMIF Prototype Accelerator (LIPAc) environment. This detector is developed for integration within STUMM (Start-Up Monitoring Module), the module to be used during the IFMIF-DONES commissioning to characterise and monitor the neutron and gamma field. The main objective is to evaluate the sensitivity of the current-mode micro ionisation chamber under pulsed radiation fields, reproducing the conditions expected during the commissioning and operation phases of IFMIF-DONES. Accurate monitoring and characterisation of pulsed radiation fields are essential to verify whether this detector maintains its sensitivity and reliability in such environment.
The LIPAc facility was selected as an ideal to perform this test due to its capability to generate radiation environments with a time-structure similar to those expected in IFMIF-DONES. For this reason, the experimental campaign focused on the current-mode micro ionisation chamber’s response under pulsed conditions. Specific objectives included evaluating signal stability, measuring response accuracy, and optimizing data acquisition methods to reduce noise and improve overall data fidelity.
To perform the test campaign, the uIC was integrated into the High Energy Beam Transport (HEBT) line at LIPAc, positioned within lead shielding near the Beam Dump to ensure exposure to radiation fields while minimizing background and electromagnetic noise.
Results demonstrated that the micro ionisation chamber could operate effectively in a pulsed radiation regime, maintaining stable and accurate measurements even under challenging conditions. Data acquisition using Keysight instruments provided insights into their relative strengths, with the electrometer exhibiting superior sensitivity for low-current measurements. The success of the micro ionisation chamber operation and data consistency in the LIPAc environment validate its potential use within IFMIF-DONES with no need to use pulsed-mode micro ionisation chambers.
