title: An absolute method for determination of misalignment of an immersion ultrasonic transducer.
abstract: An absolute methodology has been developed for quantification of misalignment of an ultrasonic transducer using a corner-cube retroreflector. The amplitude based and the time of flight (TOF) based C-scans of the reflector are obtained for various misalignments of the transducer. At zero degree orientation of the transducer, the vertical positions of the maximum amplitude and the minimum TOF in the C-scan coincide. At any other orientation of the transducer with the horizontal plane, there is a vertical shift in the position of the maximum amplitude with respect to the minimum TOF. The position of the minimum (TOF) remains the same irrespective of the orientation of the transducer and hence is used as a reference for any misalignment of the transducer. With the measurement of the vertical shift and the horizontal distance between the transducer and the vertex of the reflector, the misalignment of the transducer is quantified. Based on the methodology developed in the present study, retroreflectors are placed in the Indian 500MWe Prototype Fast Breeder Reactor for assessment of the orientation of the ultrasonic transducer prior to the under-sodium ultrasonic scanning for detection of any protrusion of the subassemblies.
authors.affiliation: Non-destructive Evaluation Division, Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, Tamil Nadu, India.
authors.forename: M M
authors.initials: MM
authors.lastname: Narayanan
authors.affiliation: R&D of Fusion Blanket Related Technologies Division, Institute for Plasma Research, Gandhinagar 382428, Gujarat, India.
authors.forename: Narender
authors.initials: N
authors.lastname: Singh
authors.affiliation: Non-destructive Evaluation Division, Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, Tamil Nadu, India. Electronic address: anish@igcar.gov.in.
authors.forename: Anish
authors.initials: A
authors.lastname: Kumar
authors.affiliation: Non-destructive Evaluation Division, Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, Tamil Nadu, India.
authors.forename: C
authors.initials: C
authors.lastname: Babu Rao
authors.affiliation: Non-destructive Evaluation Division, Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, Tamil Nadu, India.
authors.forename: T
authors.initials: T
authors.lastname: Jayakumar
keywords: Angular misalignment; C-Scan and B-scan; Corner-cube retroreflector; Spherically focused transducer; Undersodium ultrasonic transducer