TY - GEN
T1 - Ultrasonic NDE in a reactor core
AU - Parks, David A.
AU - Tittmann, Bernhard R.
PY - 2011
Y1 - 2011
N2 - We have irradiated bulk single crystal piezoelectric AlN operating as an ultrasonic transducer up to a fast and thermal neutron fluence of 1.85×10 18 n/cm 2 and 5.8×10 18 n/cm 2 respectively along with a gamma dose of 26.8 MGy. Our primary interest was in the radiation effects on the piezoelectric performance of the AlN crystal. Ideally standard procedures [2] for extracting material properties from the impedance spectra would have been applied. However, this procedure was anticipated to be very error prone due the effects of radiation on passive components, such as electrodes and cabling. As a result the transducer was coupled to an aluminum cylinder and operated in pulse echo mode throughout the irradiation. In addition to the pulse echo testing impedance data was obtained. Although, material parameters such as d 33 could not be measured in-situ during irradiation with our procedure, our work is the only publication, to the author's knowledge, showing the operation of an ultrasonic transducer in a reactor core. Further, the piezoelectric coefficient was measured prior to irradiation and found to be 5.5 pC/N which is unchanged form as grown samples, and in fact higher than the measured d33 for many as grown samples. Further proof of the viability of utilizing ultrasonic transducers in a reactor core is provided by means of successful time of flight (TOF) measurements throughout the irradiation. The TOF data was used to measure the gamma heating of an aluminum cylinder. The heating due to short lived isotopes in the Al was also detected via TOF.
AB - We have irradiated bulk single crystal piezoelectric AlN operating as an ultrasonic transducer up to a fast and thermal neutron fluence of 1.85×10 18 n/cm 2 and 5.8×10 18 n/cm 2 respectively along with a gamma dose of 26.8 MGy. Our primary interest was in the radiation effects on the piezoelectric performance of the AlN crystal. Ideally standard procedures [2] for extracting material properties from the impedance spectra would have been applied. However, this procedure was anticipated to be very error prone due the effects of radiation on passive components, such as electrodes and cabling. As a result the transducer was coupled to an aluminum cylinder and operated in pulse echo mode throughout the irradiation. In addition to the pulse echo testing impedance data was obtained. Although, material parameters such as d 33 could not be measured in-situ during irradiation with our procedure, our work is the only publication, to the author's knowledge, showing the operation of an ultrasonic transducer in a reactor core. Further, the piezoelectric coefficient was measured prior to irradiation and found to be 5.5 pC/N which is unchanged form as grown samples, and in fact higher than the measured d33 for many as grown samples. Further proof of the viability of utilizing ultrasonic transducers in a reactor core is provided by means of successful time of flight (TOF) measurements throughout the irradiation. The TOF data was used to measure the gamma heating of an aluminum cylinder. The heating due to short lived isotopes in the Al was also detected via TOF.
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U2 - 10.1109/ICSENS.2011.6126944
DO - 10.1109/ICSENS.2011.6126944
M3 - Conference contribution
AN - SCOPUS:84856818726
SN - 9781424492886
T3 - Proceedings of IEEE Sensors
SP - 618
EP - 622
BT - IEEE Sensors 2011 Conference, SENSORS 2011
T2 - 10th IEEE SENSORS Conference 2011, SENSORS 2011
Y2 - 28 October 2011 through 31 October 2011
ER -