Coincidence Correction Research Articles

Asymmetry parameter measurements by a precise technique

Aspects of a multidetector system capable of measuring asymmetry parameters with an accuracy of a few parts in 10 6 are discussed. It is shown that by having common analogue and logic elements the overall stability may be greatly improved and any necessary corrections considerably simplified. In particular the correction for accidental coincidences is negligible in most cases and the system is not too sensitive to source position or detector configuration.

Improved Determination of Calibration and Coincidence Correction Constants for Coulter Counters

Improved Determination of Calibration and Coincidence Correction Constants for Coulter Counters

Coincidence Corrections for Particle Size Determinations with the Coulter Counter

A new mathematical treatment has been given for coincidence corrections necessary in determining particle size distributions by means of a Coulter counter. The coincidence phenomenon has been divided into ``horizontal'' and ``vertical'' interactions, of which the latter is believed to predominate. Expressions are developed relating the observed count, the real number of particles, the mean diameter, and the standard deviation of a distribution. The resulting equations are rather complex, and although manual solution is not impossible, an electronic digital computer would decrease the time required.

Apparatus for Measuring the Energy Spectra of Mass-Selected Particles in Coincidence with Fission

An apparatus used to observe the energy spectrum of protons in coincidence with 14-Mev deuteron-induced fission is described. One feature is a mass identifier which operates over a range of 5 to 25 Mev and gives good separation of protons, deuterons, and tritons. Its operation depends on measuring the particle energy loss, ΔE, in a transmission counter and the residual energy, E, in a separate counter. The E and ΔE pulses are introduced into an electronic computer which in 1 μsec produces a pulse whose height is closely proportional to mass. The accuracy of mass separation is illustrated by a representative case in which less than 0.1% of the elastically scattered deuterons appear in the proton energy spectrum. In the presence of the complicating effects of cyclotron beam modulation, the chance coincidence correction to the proton-fission coincidence spectrum is made by simultaneously measuring the delayed and undelayed spectra.

Efficiency of 4p-crystal-scintillation counting: 2. Dead-time and coincidence corrections

Efficiency of 4p-crystal-scintillation counting: 2. Dead-time and coincidence corrections

Coincidence Corrections for Geiger Tubes Used with Alternating Current X-Ray Equipment

Coincidence Corrections for Geiger Tubes Used with Alternating Current X-Ray Equipment

The Half-Life of Radiocarbon (C14)

The half-life of ${\mathrm{C}}^{14}$ has been found to be 5720\ifmmode\pm\else\textpm\fi{}47 years by means of the use of mass spectrometrically analyzed ${\mathrm{C}}^{14}$${\mathrm{O}}_{2}$ as a part of the counter gas in brass wall Geiger counters. Some of the problems of absolute $\ensuremath{\beta}$-counting with internal counters have been investigated, particularly the coincidence and end corrections.