X-ray Induced Electric Currents in Anodized Ta 2 O 5 : Towards a Large-Area Thin-Film Sensor.

Autor: Brivio D; Brigham and Women's Hospital, Boston, MA 02115, USA.; Harvard Medical School, Boston, MA 02115, USA., Gagne M; Department of Physics and Applied Physics, University of Massachusetts Lowell, Lowell, MA 01854, USA.; RayWatch Inc., Hopkinton, MA 01748, USA., Freund E; Department of Physics and Applied Physics, University of Massachusetts Lowell, Lowell, MA 01854, USA., Sajo E; Department of Physics and Applied Physics, University of Massachusetts Lowell, Lowell, MA 01854, USA.; RayWatch Inc., Hopkinton, MA 01748, USA., Zygmanski P; Brigham and Women's Hospital, Boston, MA 02115, USA.; Harvard Medical School, Boston, MA 02115, USA.; RayWatch Inc., Hopkinton, MA 01748, USA.
Jazyk: angličtina
Zdroj: Sensors (Basel, Switzerland) [Sensors (Basel)] 2024 Apr 16; Vol. 24 (8). Date of Electronic Publication: 2024 Apr 16.
DOI: 10.3390/s24082544
Abstrakt: Purpose: We investigated the characteristics of radiation-induced current in nano-porous pellet and thin-film anodized tantalum exposed to kVp X-ray beams. We aim at developing a large area (≫cm 2 ) thin-film radiation sensor for medical, national security and space applications.
Methods: Large area (few cm 2 ) micro-thin Ta foils were anodized and coated with a counter electrode made of conductive polymer. In addition, several types of commercial electrolytic porous tantalum capacitors were assembled and prepared for irradiation with kVp X-rays. We measured dark current (leakage) as well as transient radiation-induced currents as a function of external voltage bias.
Results: Large transient currents (up to 50 nA) under X-ray irradiation (dose rate of about 3 cGy/s) were measured in Ta 2 O 5 capacitors. Small nano-porous Ta and large-area flat Ta foil capacitors show similar current-voltage characteristic curve after accounting for different X-ray attenuation in capacitor geometry. The signal is larger for thicker capacitor oxide. A non-negligible signal for null external voltage bias is observed, which is explained by fast electron production in Ta foils.
Conclusions: Anodized tantalum is a promising material for use in large-area, self-powered radiation sensors for X-ray detection and for energy harvesting.
Databáze: MEDLINE
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