摘要:

Deuterium-loaded nuclear emulsions have been used to study the γ-rays of neutron capture in sodium, chlorine, and cadmium, and the γ-rays following the β-decay of N16. Proton tracks caused by the photodisintegration of deuterium were measured, and from these the γ-ray energies were calculated. Several lines have been observed in the γ-ray spectra of neutron capture. The known energy of the 6.124 Mev. γ-ray following the decay of N16(produced in the cooling water of the Chalk River pile) was used to calibrate the plates. A higher energy γ-ray from the decay of N16was tentatively identified as corresponding to a transition from the 6.897 Mev. excited level of O16to the ground state and was found to have one-seventh the intensity of the 6.124 Mev. γ-ray.

ISSN:1923-4287    

DOI:10.1139/cjr50a-038

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

The emission band system at 6000 Å found in discharges in flowing NO2and attributed to NO+by Jausserant, Grillet, and Duffieux has been examined at high dispersion and shown to be due to the transition ofE2Σ+(a new level) → A2Σ+(the upper state of the γ system) of the NO molecule. The rotational and vibrational analysis of the system is given. The band system corresponding to the transitionD2Σ+(upper state of the ϵ system of NO) → A2Σ+at 11,000 Å has also been observed and its analysis is presented. The separate nature of theD2Σ+state from theA2Σ+state is thus supported. Some brief remarks on other band structures found in discharges in flowing NO2are included.

ISSN:1923-4287    

DOI:10.1139/cjr50a-039

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

The measurement of the energy distribution of fission fragments has been extended to include fragments from fission in Pu239. The same equipment was used as in previous experiments on U235and U233. The experimental results parallel very closely those obtained in the previous work. The values obtained for the most probable energies for the light and heavy fragments from Pu239are 94.6 and 65.2 Mev. respectively. The statistical accuracy of the data is, as before, an improvement over earlier work in this field, and a more detailed comparison of the three materials is made possible.

ISSN:1923-4287    

DOI:10.1139/cjr50a-040

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

The velocity of sound in pure helium gas has been measured as a function of pressure at −78°, 0°, 50°, 100°, and 200 °C., using an ultrasonic interferometer of the double crystal type. From the sound velocity data second viral coefficients were obtained, and the ratio of specific heats was derived as a function of pressure.

ISSN:1923-4287    

DOI:10.1139/cjr50a-041

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

The calorimetric method of measuring sources is of value when the average energy per disintegration is known, and may be used to check the accuracy of an "absolute" beta counting technique. This paper describes a differential calorimeter designed for this type of measurement, and an experimental determination of the disintegration rate of a P32source. The calorimetric measurement gave a value of the disintegration rate with a probable error of 0.7% differing by 1.8% from the result obtained from an absolute count of the β-activity. The absolute count was accurate to ±2%. The calorimeter has a sensitivity limit of less than 10 μw., and makes use of thermistors to measure temperature changes of the order of 10−3°C.

ISSN:1923-4287    

DOI:10.1139/cjr50a-042

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

A special specimen holder has been constructed for the evaporation of metals within an RCA–EMU electron microscope. This provides continuous observations on the growth of films of the metal. Micrographs are reproduced which illustrate the formation of films of silver, gold, and tin. The results confirm the usually accepted assumptions regarding the formation of nuclei and the growth of aggregates.

ISSN:1923-4287    

DOI:10.1139/cjr50a-043

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

Four determinations of gravity were made during the summer of 1948, with the pendulum apparatus of the Dominion Observatory, at Goose Bay, Labrador (latitude 53°), Frobisher Bay, Baffin Island (latitude 64°), Resolute Bay, Cornwallis Island (latitude 75°), and Thule, Greenland (latitude 77°), approximately. The anomalies at the two most northerly stations are comparatively small and those at the other two stations, although larger, do not exceed many that have been observed in other parts of Canada. Norgaard's determination at Thule is confirmed by the author.It is anticipated that these determinations, apart from their immediate interest, will serve as useful reference points for future work in the Canadian Arctic.

ISSN:1923-4287    

DOI:10.1139/cjr50a-044

出版商:NRC Research Press    

年代:1950

数据来源: NRC

摘要:

With a view to testing the adequacy of the perturbation theory as applied to radiationless transitions in light atoms, the probability of such a transition in the Be atom from the 1s22p3s3Pstate to the continuum 1s22s+ ejectedpelectron has been calculated. The wave functions employed for the discrete states are obtained by the variational method and the wave function for the continuous state by numerical integration of the Schrodinger equation. The transition probability obtained is 5 × 1013per second, leading to a width of ~ 290 cm.−1for the level 1s22p3s3P. This is at least 103times larger than what is indicated by the observed widths of the spectral lines. Thus the present calculation, together with similar earlier calculations for the He atom, shows that the perturbation theory is inadequate for the light atoms.It is also pointed out that there is an inconsistency in the use of the perturbation theory in these calculations and those on the Auger effect in the literature since the use of variational or "screened" wave functions implies that a part of the electron–electron interaction has already been included in the initial approximation, and it is hence incorrect to treat this whole interaction as the perturbation causing the transition.

ISSN:1923-4287    

DOI:10.1139/cjr50a-045

出版商:NRC Research Press    

年代:1950

数据来源: NRC