Metal Hall sensors for the new generation fusion reactors of DEMO scale

Abstract

For the first time, the results of on-line testing of metal Hall sensors based on nano-thickness (50–70) nm gold films, which was conducted under irradiation by high-energy neutrons up to the high fluences of 1 · 1024 n · m−2, are presented. The testing has been carried out in the IBR-2 fast pulsed reactor in the neutron flux with the intensity of 1.5 · 1017 n · m−2 · s−1 at the Joint Institute for Nuclear Research. The energy spectrum of neutron flux was very close to that expected for the ex-vessel sensors locations in the ITER experimental reactor. The magnetic field sensitivity of the gold sensors was stable within the whole fluence range under research. Also, sensitivity values at the start and at the end of irradiation session were equal within the measurement error (<1%). The results obtained make it possible to recommend gold sensors for magnetic diagnostics in the new generation fusion reactors of DEMO scale.

Ceramic-Chromium Hall Sensors for Environments with High Temperatures and Neutron Radiation

“…In the case of inner-vessel sensors, the sensor temperature will be in the range of 300 to 520 • C [23,24]; the higher operating temperature compared to ITER exceeds the range of applicability of the bismuth sensors as bismuth melts at 271.4 • C. Therefore, several metal sensitive layers that can operate at these temperatures have been researched [22,23]. Gold-based Hall sensors for fusion reactor application were developed at the Magnetic sensor laboratory of Lviv Polytechnic National University in Ukraine (MSL) [25,26], and antimony-based Hall sensors operating up to a temperature of 550 • C were developed at IPP [27]. Unfortunately, both gold and antimony are easily subjected to transmutation in neutron flux and are therefore not sufficiently resistant to neutron radiation [28].…”

Automation System for Transporting Highly Radioactive Samples of the Irradiation Facility of the IBR-2 Reactor

“…The robot is equipped with a pneumatic gripper (5) with a laser target designator (10) (Fig. 2) for automatic gripping and transportation of radioactive wastes, as well as a high-resolution camera (11) for remote control. Remote programming and control over the robotic manipulator are also performed by means of video cameras (4) arranged at different points of the CZ, overlapping all fields of vision.…”

“…The high density of the neutron flux interacting with the sample under investigation leads to a quite high induced activity of both the sample itself and the structural elements of the irradiation facility. As a rule, all samples after irradiation can be conditionally divided into two groups: those requiring the urgent neutron activation analysis of short-lived isotopes (from a few hours to 2 days after irradiation), for example, [5][6], and those that do not require such an analysis [7][8][9][10][11]. Taking into account the fact that, in the first hours after irradiation, the main contribution to the induced radioactivity is usually made by short-lived isotopes; then the transportation of their samples from the structural elements of the facility may become a problem because of extremely high values of radioactivity (up to 1 Sv/h).…”

Engineering of Advanced Materials for High Magnetic Field Sensing: A Review

“…Specially designed B-dots [ 18 ] or Faraday-effect magnetic field sensors [ 19 ] are applied in more specific equipment. However, to decrease the dimensions of the sensor and the measurement setup, solid-state based materials such as Hall sensors are preferable [ 20 , 21 ]. One can find more detailed information about Hall sensors in other review papers [ 22 , 23 ].…”