The Three-Photon Annihilation of Positrons and Electrons [Thesis]

Thesis/Dissertation · Mon May 26 04:00:00 EDT 1952

OSTI ID:4382606

Siegel, Robert T. ^[1]

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1. Carnegie Inst. of Technology, Pittsburgh, PA (United States)

The three-photon annihilation of positrons and electrons has been investigated experimentally by means of a triple coincidence technique. Three Nal(Tl) scintillation counters in coincidence were used to study the occurrence of the triplet annihilation process when positrons annihilate against the electrons within solids, liquids, and liquefied gases. The annihilation rates in aluminum, liquid nitrogen, and liquid Freon-12 (CCl₂F₂) were compared with the theoretical predictions made under the assumption that free positron-electron pairs produced all annihilation events; experiment and theory agreed within the experimental error. The formation of stable ortho-positronium in Freon-12, SF₆, N₂, H₂, and He was verified and its comparative stability in these gases measured. The spectra of the annihilation rays from ortho-positronium were measured to demonstrate that energy and momentum are conserved in the three-photon annihilation process.

• Research Organization: Carnegie Inst. of Technology, Pittsburgh, PA (United States)
• Sponsoring Organization: US Atomic Energy Commission (AEC)
• NSA Number: NSA-06-004918
• OSTI ID: 4382606
• Report Number(s): NYO--3302; WO--24928
• Country of Publication: United States
• Language: English

Related Subjects

ALUMINUM
ANNIHILATION
COINCIDENCE METHODS
ELECTRONS
ENERGY
ERRORS
FLUORINATED HYDROCARBONS
FREONS
GAMMA RADIATION
GASES
HELIUM
HYDROGEN
LIQUIDS
MEASURED VALUES
MOMENTUM
NITROGEN
PHOTONS
POSITRONS
SCINTILLATION COUNTERS
SODIUM IODIDES
SOLIDS
SPECTRA
STABILITY
SULFUR FLUORIDES
THALLIUM