The calculation of the shadow factor of single coil filament
A computer method for calculating the power-reduction factor of a single-coil filament is presented. The filament of incandescent lamps is coiled, which is why a fraction of radiation is trapped in the filament. The relationships between the geometric parameters of a cylindrical helix (pitch ratio and mandrel ratio) and the shadow factor are developed. A FORTRAN program based on the numerical solution of algebraic equations and on three-dimensional numerical integration has been developed.<<ETX>>
Filaments for Incandescent Lamps with Energy Conserving Envelopes
The design considerations for filaments in energy conserving incandescent lamps are described. Such lamps require compact high emissivity filaments to absorb infrared radiation reflected from heat mirrored focusing envelopes. The relationships between the electrical parameters in the radiation returning environment and in the clear surroundings are developed. Efficiency experiments with filaments of various geometries under conditions of radiation return were performed. A highly compact coiled coil filament seems most promising for development. A calculation is presented of the filament emissivity as a function of spacing of the windings in a coil. Measurements of the emissivity as a function of the pitch of a coiled coil filament agree with the calculation.
A slowly rotating coil system for AC field measurements of Fermilab Booster correctors
A method for measurement of rapidly changing magnetic fields has been developed and applied to the testing of new room temperature corrector packages designed for the Fermilab Booster Synchrotron. The method is based on fast digitization of a slowly rotating tangential coil probe, with analysis combining the measured coil voltages across a set of successive magnet current cycles. This paper presents results on the field quality measured for the normal and skew dipole, quadrupole, and sextupole elements in several of these corrector packages.