The performance of NASA research hydrogen masers

Field operable hydrogen masers based on prior maser designs are presented. These units incorporate improvements in magnetic shielding, lower noise electronics, better thermal control, and have a microprocessor for operation, monitoring, and diagnostic functions. They are ruggedly built for transportability and ease of service anywhere in the world

Parametric fit to electron transport properties

Experimental data acquired over the past few years were gathered, and parametric fits made to these data. The following properties of electron transport were represented by simple functions of atomic number and energy: transmitted electron number, transmitted electron spectra, range, backscatter coefficient, angular distribution, energy deposition, bremsstrahlung intensity and energy spectra, and bremsstrahlung angular distribution and photon attenuation. The formulas cover the energy ranges of interest in space shielding problems (0.1 to 10.0 MeV). Procedures for using these formulas in practical situations are suggested

Experimental results on mass-thickness distribution in spacecraft equipment

A technique is described for evaluating the shielding properties of spacecraft equipment with respect to cosmic radiation. A gamma-ray source is used in conjunction with a scintillation detector to determine mass-thickness distribution both in plane geometry for equipment units, and in spherical geometry for given points within the spacecraft. Equations are presented for calculating mass-thickness distribution functions, and the results are compared with experimental measurements

Ab initio Calculation of Magnetic Shielding and Susceptibility. I. Molecular Integrals over Gauge Invariant Gaussian Orbitals.

The analytical solutions· for the integrals needed in the SCF computation of magnetic shielding and susceptibility with gauge invariant Gaurssian atoiniC functions . are \u27described. All the integrals can be expressed in terms of known functions

Ab initio Calculation of Magnetic Shielding and Susceptibility. I. Molecular Integrals over Gauge Invariant Gaussian Orbitals.

The analytical solutions· for the integrals needed in the SCF computation of magnetic shielding and susceptibility with gauge invariant Gaurssian atoiniC functions . are \u27described. All the integrals can be expressed in terms of known functions