A Re-Evaluation of the Fundamental Atomic Constants

Abstract

A completely new evaluation of the fundamental atomic constants by the method of least squares is presented. A number of new and highly precise experiments have been taken into account, including the measurement of: (1) the velocity of light by an exceptionally ingenious and precise method due to Hansen and Bol, (2) the absolute proton moment, (3) the ratio of magnetic moments of proton and electron, (4) the proton moment in Bohr magnetons, (5) the hyperfine structure separation of ground-state hydrogen, (6) the ratio of cyclotron to precession frequency of the proton, (7) h/mc using annihilation radiation, and (9) h/e from the x-ray high frequency limit with improved precision.The results of the critical survey of Dorsey on the velocity of light plus the more recent measurements of c are combined to obtain a weighted-mean value: c=299790.0±0.7 km/sec. The results of the experiments listed above have been combined by several writers to compute a, e/m, and F. All of the published values, including those of certain older experiments have been corrected for the new value of c and combined in a least-squares calculation. The results are presented in a complete table of the fundamental constants and are compared with the experimental values in an isometric consistency chart. Six of the experimental results: F, N, mN, a, e/rn, and h/e are found to show excellent agreement with the least-squares values. In particular the new experimental value of Ve= =s (l-37928±0.00004)X10 17 erg sec/esu which precipitated the present work agrees well with the leastsquares value, Ve=(l-379300±0.000016)X10-17 erg-sec/esu.

Recommending a value for the Newtonian gravitational constant

“…Earlier work [2][3][4][5][6] often used a least-squares analysis (LSA) to provide self-consistent values for a set or subset of fundamental constants. The TGFC continues this approach but it has been extended to include virtually all of the essential fundamental constants and to account for the functional and experimental correlations.…”

“…It is generally agreed that Birge [1] was the first to attempt an adjustment of the values of the fundamental constants (and it seems most appropriate that this reference is the first page of the first volume of Review of Modern Physics). In the intervening time, others have made similar adjustments [2][3][4][5][6], but it eventually became apparent that a single source of these adjustments with broad international acceptance would provide the most benefits. This is why the CODATA Task Group on Fundamental Constants (TGFC) came into being.…”

Editorial: Proceedings of the 2015 Workshop on the Determination of the Fundamental Constants

“…57,58 During this time period, Bearden and coworkers also contributed to the work of this NRC subcommittee and published a series of papers making recommendations for some of the fundamental constants and providing some discussion about inconsistencies, uncertainties, and evaluation methods. [59][60][61][62][63][64] A summary report by the NRC committee was published in 1952. 65 In 1966, the CODATA was established by the International Council of Science, and in 1969, the CODATA Task Group on Fundamental Constants was formed.…”

Gamma-Ray Dose-Rates from Radioactive Isotopes

“…The quantity having general practical significance is the y-ray dose-rate in roentgens per hour in air at 1 em from 1 millicurie of a radioactive isotope which for convenience, is referred to in what follows as the K factor. The experimental evaluation of the K factor for a particular radioactive isotope involves the determination of two quantities namely the disintegration rate of a sample of the isotope and the y-ray dose-rate at 1 ) have participated in a programme of inter-comparisons of different methods of measuring absolute disintegration rates by counting methods. The programme (9) has also in-eluded measurements of y-ray dose-rates, primarily with the object of deriving disintegration rates by using the theoretical K factors.…”