MEDRADSC 2F03 Lecture Notes - Lecture 8: Induction Motor, Rhenium, Mammography

• School: McMaster University
• Department: Medical Radiation Sciences
• Course: MEDRADSC 2F03
• Professor: Lumsden

Document Summary

Kvp signals the electrons produced at the cathode to move to the anode. Electrons travel through a vacuum x-ray tube is made of heat resisted glass (sometimes metal), oil and fans. Struck by the electron beam= focal spot. Made of tungsten/rhenium: tungsten has a high melting point to withstand heat and high z for more efficient x-ray production, rhenium adds strength and prevents surface damage. Mammography uses molybdenum or rhodium: lower z of molybdenum/rhodium. Made of molybdenum: poor ther(cid:373)al co(cid:374)ductor, so all the heat is(cid:374)"t pitted i(cid:374)to o(cid:374)e area. Part of induction motor outside the tube around the rotor. Made of electromagnets: powers the induction motor. Rotor assembly is the moving field created by the stator: rotates anode disc, copper: electrical conduction. Moving magnetic field induces an electrical current in the copper of the rotator. Current in the rotor creates an opposing magnetic field to stator magnetic field rotor spins. Small area gives us better image production: lower ma.