CMOS sensor as ionizing radiation detector and thermoluminescence response
Por:
Cruz-Zaragoza, E., López, I.P.
Publicada:
1 ene 2015
Resumen:
The CMOS active pixel sensors have has been tested for several applications including in radiation field. This type of sensors has an Active Pixel Sensor which is formed by an integrated circuit with a matrix of pixels where each pixel itself contains a photodetector. An assortment of new perspectives in various research areas could be opened by a different type of devices such as CMOS sensors. These devices could be used for detection of ionizing radiation with the possibility of a submicrometer measurement. In a previous work, we have investigated the possibility of using a CMOS sensor with an area of 640 × 480 pixels and the pixel size was less than 2 micrometers, which previously has been integrated into an electronic circuit for detection of ionizing radiation and charged particles testing from radioactive sources at the Nuclear Sciences Institute (UNAM) of Mexico; such as: Am-241, Natural Uranium (U-234, U-235 and U-238), Sr-90, and Cs-137. The CMOS sensor response was appropriated in each variations of energy from the radioactive sources. The area and positions of the sensor surface where the particles and gamma rays impacted them were determined and the higher peaks show each energy type from radiation source. Because the CMOS sensor was tested during 168 h (1 week) using the largest energy source (Am-241) with a good response and without loss of functionality, then the layers (Ge:Si and SiO2) of the CMOS were tested under high gamma doses (200-5000 Gy) from 60Co in a Gammabeam 651PT-Nordion irradiator at UNAM. The aim of this paper is to analyze the thermoluminescence (TL) response of the samples layers of the CMOS under irradiation using a liquid nitrogen (LN2) atmosphere and at room temperature. The samples show an abroad glow curves and high TL intensity. The maximum temperature of the glow peaks were observed at 127°C for Ge:Si and 320°C for SiO2, respectively. In this last case, a linear TL response between 200-3000 Gy was observed. The CMOS sensor should be useful to use as an active and passive detector also in order to prevent and monitoring the radiation damage due to the high dose in the environment radiation conditions of the spacecraft.
Filiaciones:
Cruz-Zaragoza, E.:
Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, A.P. 70-543, Mexico D.F., Mexico
López, I.P.:
Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico
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