Index of content:
Volume 14, Issue 4, April 1943
14(1943); http://dx.doi.org/10.1063/1.1770138View Description Hide Description
Hollow cylindrical rotors with slotted walls can be used as substitutes for sector disks for some photometric applications. Designs are given of rotors which can replace a logarithmic sector, fixed sector disk, step sector, and variable sector disk. Some of these rotors may be used with non‐parallel light. A rotor corresponding to a variable sector disk has been built with a variable slot which can be adjusted to several different openings while inside a vacuum system.
14(1943); http://dx.doi.org/10.1063/1.1770139View Description Hide Description
A method is described for removing the microscopic fog found in commercial photographic emulsions. The removal of the fog makes a greater number of emulsions available for recording tracks of nuclear particles. An example of this application is shown in photomicrographs of the tracks of polonium alpha‐particles in treated and untreated lantern slide plates.
14(1943); http://dx.doi.org/10.1063/1.1770140View Description Hide Description
To carry over interruptions in the supply of liquid air, a 120‐l triple‐wall, silver‐plated, metal vacuum vessel was designed and built. The radiation theory for its part of the evaporative loss was worked out. The observed and calculated total loss agree at 3 kg/day. The good initial vacuum is maintained by the presence of an ample supply of activated charcoal in a small sphere reentrant into the large inner sphere. The alloy Inconel is used for situations requiring small conductivity. Alternative effective designs are given for the lower centering support for the inner spheres. The vessel is filled and emptied through an opening in the bottom, and this is controlled by a valve of ordinary design. To hasten the discharge the pressure over the liquid is raised slightly by throttling the vapor discharge. The vessel has been in use for 2.5 years without observed change in its evaporative loss.
- LABORATORY AND SHOP NOTES
14(1943); http://dx.doi.org/10.1063/1.1770134View Description Hide Description