Micromechanical High-doses Radiation Sensor with Bossed Membrane and Interferometry Optical Read-out

AbstractThe silicon-glass MEMS high-doses radiation sensor with in situ detection, so far not possible in the field of detection of doses above 10 kGy, has been presented. The sensor consists of a chamber filled with the high density polyethylene (HDPE) and a silicon bossed membrane. The radiolysis product of HDPE increases the pressure inside the chamber causing the deflection of the membrane, which is proportional to the pressure, thus to radiation dose. The sensor has been irradiated with high energy electron beam and shows good detectability for 10-40 kGy. The deflection of the membrane has been detected by optical interferometer

Synergistic Effect of ELF-Magnetic Field and IR-Radiation on Tinnitus Patients

The LED light therapy and magnetostimulation is an innovative method of treatment used in Viofor JPS System. Simultaneous application of both types of electromagnetic radiation increases the therapy effectiveness by the synergy effect. It is recommended in analgesic, anti-inflammatory treatment, and to support immune system of the organism. The mechanism of biological effect of variable magnetic fields and light are of similar nature at the tissue level. When applying magnetostimulation and light together, it shortens the time of therapy. The LED light therapy and magnetostimulation is supposed to be an alternative supporting method to therapies used to treat tinnitus so far

MEMS HIGH-DOSES RADIATION SENSOR

International audienceNew MEMS sensor for detection of high doses (above 10 kGy) of radiation has been presented. The sensor is made of silicon and glass in a form of anodically bonded sandwich 9 × 16 × 2.6 mm3. The sensor contains chamber with small portion of high density polyethylene (HDPE) and thin silicon membrane. Irradiation releases gaseous hydrogen, which flows from the chamber to the membrane. For known radiation dose pressure of hydrogen destroys the membrane, what is optically noticed. The sensor show good detectability of doses of radiation up to 120 kGy

Micromechanical high-doses radiation sensor with bossed membrane and interferometry optical detection

International audienceThe silicon-glass MEMS high dose radiation sensor with the optical read-out, acting above 10 kGy has been presented. The sensor consists of a microchamber filled with small portion of high density polyethy-lene (HDPE) and thin silicon membrane. The principle of operation of the sensor is based on radiolysis effect of the HDPE which, upon radiation exposure, releases the hydrogen. The hydrogen increases the pressure inside the microchamber causing the deflection of the membrane, which is proportional to the pressure, thus to radiation dose. The sensor has been irradiated with high energy electron beam with dose 5 ÷ 40 kGy. The displacement of the membrane has been detected by optical interferometer. The relative generated pressure inside the sensor chamber has been found very high (up to 180 kPa). It shows that response of a micro-scaled MEMS sensor is much more effective in comparison to macro-scaled solutions

Micromechanical high-doses radiation sensor with bossed membrane and interferometry optical detection

International audienceThe silicon-glass MEMS high dose radiation sensor with the optical read-out, acting above 10 kGy has been presented. The sensor consists of a microchamber filled with small portion of high density polyethy-lene (HDPE) and thin silicon membrane. The principle of operation of the sensor is based on radiolysis effect of the HDPE which, upon radiation exposure, releases the hydrogen. The hydrogen increases the pressure inside the microchamber causing the deflection of the membrane, which is proportional to the pressure, thus to radiation dose. The sensor has been irradiated with high energy electron beam with dose 5 ÷ 40 kGy. The displacement of the membrane has been detected by optical interferometer. The relative generated pressure inside the sensor chamber has been found very high (up to 180 kPa). It shows that response of a micro-scaled MEMS sensor is much more effective in comparison to macro-scaled solutions

High doses wireless radiation sensor using electromagnetic transducers

International audienceThis communication reports the last results obtained on the development of a wireless passive chipless sensor for high doses radiation monitoring. The sensor is based on polymer out-gazing inside a micro-chamber coupled with electromagnetic pressure transducer. Previous results on test structures have validated the principle of polymer out-gazing under nuclear radiation. An hermetic sealed prototype including the micro-chamber and the pressure transducer is reported here for the first time. This sensor has been fabricated successfully. Experimental results are reported and discussed

Wireless Hydrogen Pressure Dosimeter for Nuclear High Dose Monitoring

International audienceThis communication reports the very first experimental results on an original wireless, chipless and passive (battery-less) sensor for monitoring high doses of nuclear radiation. The micro-sensor combines a miniature hydrogen pressure dosimeter with a passive microwave resonator. The pressure response is derived from S11-parameter measurement using vacuum and atmospheric pressure conditions. After e-beam irradiation (20kGy) the resonant frequency shift of the resonator ranges between 0.12%/kGy and 0.42%/kGy while the hydrogen pressure inside the cavity varies from 20mbar/kGy to 90mbar/kGy. No significant frequency shift is observed when using sensors during 6 months. These results demonstrate that a good hydrogen hermetic seal was fabricated during the manufacturing process of the constitutive micro-cavity

Wireless and chipless passive radiation sensors for high dose monitoring

International audienceThe safety of nuclear infrastructures may involve the monitoring of many parameters in harsh environments (high radiation level, high temperature, high pressure, ..). If technological solutions exist for transducers part in such environments, the electronic part used in reader is not appropriate and still a challenging task. Well-known solutions to remove the electronic part from the harsh environment consist of connecting the transducer and the reader by long electrical wires or performing ex situ remote sensing. However wires may practically be difficult to implement while ex situ measurements are not compatible with on line monitoring. Wireless and passive sensors working in harsh environments could be an appropriate solution for the remote sensing of critical parameters. Passive sensors without electronics in the sensing unit are available (e.g., SAW sensors) but they suffer from short reading range (typically lower than 10 meters). In order to overcome this range limitation a new class of electromagnetic transducers was developed in the mid-2000s. The operating principle is based on the modification of the properties of high-frequency (>> 1 GHz) passive electromagnetic devices by the quantity to be measured. Based on this principle a wide range of sensing properties can be addressed and a large number of materials can be chosen. Moreover the use of high frequency allows reducing the size of the sensor elements (antenna, transducer) and enhancing the immunity to multipath. Several principles of RF transducers have been already validated by LAAS-CNRS (e;g; pressure [1], temperature [2], stress [3]) as well as radar-based solution for the wireless long-range sensors interrogation [4]. The sensor dosimeter exploit here the known property of Hydrogen-Pressure Dosimeters (HPD) for which the polymer material dehydrogenates under nuclear irradiation. The transducer principle is described in Figure 1. The irradiation will generate the out-gazing (hydrogen) of the polymer inside a micro-chamber. The resulting overpressure leads to the deflection of a silicon membrane which modifies the resonant frequency of the RF resonator. 9µ