Ionization Effects Produced in Diamonds Subjected to Mono-Energetic β-ray Bombardment

Journal Article · Tue Nov 17 04:00:00 EST 1959 · Proceedings of the Royal Society. A. Mathematical, Physical and Engineering Sciences

DOI:https://doi.org/10.1098/rspa.1959.0177· OSTI ID:4206672

Kennedy, P. J.

The ionization produced within diamond specimens by the passage of high- energy beta rays was investigated using the methods of conduction pulse counting, and a new technique was developed to enable pulse-height spectra to be taken, rapidly and in quick succession, under widely different experimental conditions. It is shown that only a small proportion of the incident beta rays may dissipate their total energy within the specimen and that pulse-height spectra can be interpreted successfully only when a conduction pulse is related to the energy lost by the electron producing it. Under conditions of saturation field strength and low crystal polarization. the conduction pulse magnitude is proportional to the energy dissipated. The mean value of energy per ion ptiir is thus independent of the primary electron energy and the experimental yalue of 20 ey is shown to be remarkably consistent between diamond specimens. This value differs from the previously accepted value of 10 ev and, if used tn preference to 10 ev, removes many apparent anomalies from previously published work. A theory is outlined in which it is proposed that the degradation of the primary electron energy takes place principally by interaction with the valence electrons of the crystal. The mean energy per ion pair depends, not only on the width of the forbidden gap In the solld, as previously suggested, but also on the width of the valence band and particularly on the position of the maximum in the density of states curve within the valence band. The available data for diamond suggest a value of approximately 18 ev for the mean ionization energy. This value is consistent with the experimental value from the maximum pulse height under saturation conditions. The finite breadth of the pulse spectra, can be explained only by some charge-reducing process occurring after the total dissipation of the incident energy. The process is tentatively linked with the scintillation response of the diamond crystal. Criteria are suggested by which the conduction pulse response of various solids may be predicted.

• Research Organization: Wheatstone Lab., King's Coll., London
• Sponsoring Organization: USDOE
• NSA Number: NSA-14-006734
• OSTI ID: 4206672
• Journal Information: Proceedings of the Royal Society. A. Mathematical, Physical and Engineering Sciences, Journal Name: Proceedings of the Royal Society. A. Mathematical, Physical and Engineering Sciences Journal Issue: 1272 Vol. 253; ISSN 1364-5021
• Publisher: The Royal Society Publishing
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

BEAMS
BETA PARTICLES
BETA SPECTROMETERS
COUNTERS
CRYSTALS
DIAMONDS
DISTRIBUTION
ELECTRIC CHARGES
ELECTRIC CONDUCTIVITY
ELECTRIC FIELDS
ELECTRONS
ENERGY
ENERGY DISSIPATION
ENERGY LEVELS
ENERGY LOSSES
ERRORS
INTERACTIONS
ION PAIRS
IONIZATION
IONS
LOSSES
MEASURED VALUES
METALS
CERAMICS AND MATERIALS
PAIR PRODUCTION
POLARIZATION
PULSES
RADIATION EFFECTS
SEMICONDUCTORS
SOLIDS
SPECTRA
VALENCE
VALENCE ELECTRONS