magnetic shields for photomultiplier tubes

Code Number: 5G20.55

Demo Title: Permalloy Rods

Condition: Good

Principle: Earth's Magnetic Field

Area of Study: Electricity & Magnetism

Equipment:

Permalloy Rod and Strips.

Procedure:

When held parallel to the magnetic field (North and South) of the Earth you will be able to pick up strips with the permalloy rod just like a magnet. When turned 90 degrees to the Earth's magnetic field (East and West) the strips will fall off the rod. The Mu-Metal shields are also made from permalloy material. These are used to prevent the penetration by magnetic fields into a detector. In this case these are magnetic shields for photo multiplier tubes.

References:

G. D. Freier and F. J. Anderson, "Er-9", A Demonstration Handbook for Physics.
Wallace A. Hilton, "E-6a", Physics Demonstration Experiments.
George M. Hopkins, "Magnetism", Experimental Science, p. 347.

Disclaimer

These demonstrations are provided only for illustrative use by persons affiliated with The University of Iowa and only under the direction of a trained instructor or physicist. The University of Iowa is not responsible for demonstrations performed by those using their own equipment or who choose to use this reference material for their own purpose. The demonstrations included here are within the public domain and can be found in materials contained in libraries, bookstores, and through electronic sources. Performing all or any portion of any of these demonstrations, with or without revisions not depicted here entails inherent risks. These risks include, without limitation, bodily injury (and possibly death), including risks to health that may be temporary or permanent and that may exacerbate a pre-existing medical condition; and property loss or damage. Anyone performing any part of these demonstrations, even with revisions, knowingly and voluntarily assumes all risks associated with them.

Instructional Resources and Lecture Demonstrations

5G20.55 - Permalloy Rods

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