beta-ray spectrometer cavity
Date: 1947-1951
Inventory Number: RS0326a
Classification: Spectrometer
Subject:
User: Walter L. Brown (born circa 1925)
Maker: Department of Physics, Harvard University ? (founded 1884)
Cultural Region:
Place of Origin:
Dimensions:
44.1 x 26.7 x 5.7 cm (17 3/8 x 10 1/2 x 2 1/4 in.)
Material:
Accessories: spectrometer magnet and tripod (RS0326); mount parts (RS0326b and rs0326c)
Description:
Semicircular metal cavity with 2 square metal boxes on out-side (with one side covered with just paper), adjacent to each end, and an irregularly-shaped metal tube attached at one end which ends in a ring fitting with screws.
Signedunsigned
FunctionInstrument used to determine the energy distribution of beta particles and secondary electrons. It was very likely shop-made at Harvard's Physics Department.
Beta particles (or "rays") are electrons flying at high speeds as a result of nuclear decay. Their speeds (hence energies) vary depending on the specific nuclear process from which they originate. A beta-ray spectrometer is the means for determining the speed distribution of beta particles.
Since electrons are electrically charged, they move in a circle in the presence of a magnetic field, and the radius of that circle depends on the electron's speed. This is a very easy way to separate electrons from the same source into different streams depending on their speed. Afterwards, one can either select a specific stream for further experimentation, or just place a photographic plate or other detector at the spectrometer's exit to see the different paths marked on the paper.
A beta-ray spectrometer is also similar in principle to the mass spectrometers that were used to separate different isotopes of Uranium for the atomic bomb.
Part RS0326 is the tripod and electromagnet.
Part RS0326a is the spectrometer cavity, which is used inside the magnet's magnetic field, and inside which the electrons describe a circular path.
Part RS0326b attaches to the back of the semicircular cavity, and the lead block shields the radiation escaping from the cavity.
Part RS0326c is a wooden mounting block.
Beta particles (or "rays") are electrons flying at high speeds as a result of nuclear decay. Their speeds (hence energies) vary depending on the specific nuclear process from which they originate. A beta-ray spectrometer is the means for determining the speed distribution of beta particles.
Since electrons are electrically charged, they move in a circle in the presence of a magnetic field, and the radius of that circle depends on the electron's speed. This is a very easy way to separate electrons from the same source into different streams depending on their speed. Afterwards, one can either select a specific stream for further experimentation, or just place a photographic plate or other detector at the spectrometer's exit to see the different paths marked on the paper.
A beta-ray spectrometer is also similar in principle to the mass spectrometers that were used to separate different isotopes of Uranium for the atomic bomb.
Part RS0326 is the tripod and electromagnet.
Part RS0326a is the spectrometer cavity, which is used inside the magnet's magnetic field, and inside which the electrons describe a circular path.
Part RS0326b attaches to the back of the semicircular cavity, and the lead block shields the radiation escaping from the cavity.
Part RS0326c is a wooden mounting block.
Historical AttributesThis mass spectrometer was used by Walter Lyons Brown for his Physics Dissertation at Harvard.
Curatorial RemarksNote: measure transition in energy calibration--thesis project of Walter Brown.
