QUARTERLY PROGRESS REPORT NO. 51 FOR PERIOD ENDING OCTOBER 15, 1958
8 2 5 ; nics. By means of ZnS probe crystals the electric conductivity of ZaS crystals was investigated. Experiments to correlate changes in surface-trap density of Ge and changes in contact potential are described. Data previously reported on the characteristics of semiconductor junctions is analyzed, A transistorized low-voltage regulated power supply has been developed, Microwave Gaseous Discharges. Some results from measurements of noise in d-c helium discbarges over a large range of parsrneters are given and discussed. Some of the properties of a particular microwave cavity used for containment of charged particles are discussed. The apparatus used and the experiments performed in a study of the interaction of a plasma beam with a magnetic field are described. The effect of the plasma on the impedance of a coil loaded with a coaxial plasma is shown, taking account of ions and proper boundary conditions at the edge of the plasma. Plasma Dynamics. The dynamics of wave propagation in a hydromagnetic waveguide were studied. Expressions for relating the upstream parameters of a magnetohydrodynamic shock to its downstream parameters are discussed, and construction and instrumentation of a T tube for magnetically driven shocks are described which will be used to verify the discussion. Solid State Physics. The 3 adiabatic elastic constants of Nal were measured at 170 to 300 deg K by an ultrasonic pulse-echo technique. A study of the recombination of electrons with donors is extended. Microwave Spectroscopy. Ruby with 0.01% Cr/ sup 3+/ impurity was used as a paramagnetic crystal in an attempt to excite and detect lattice phonons. Experiments were performed in an attempt to detect phonou-spin absorption in F-center quartz and in potassium chromicyanide. Operation of a tunable ruby maser with large bandwidth is described. Reports are given from studies of antiferromaunetic resonance in MnCl/sub 2/, paramagnetic resonance in ruby, and dependence of spin-lattice relaxation time of F/sup 19/ in LiF crystals upon the concentration of radiation-induced F-centers. Nuclear Magnetic Resonance and Hyperfine Structure. The hyperfine structure and isotope shifts of TI/sup 199/ and TI/sup 200/ were studied spectroscopically. The relation between the g-factors and lifetimes of the excited states of two- electron atoms such as Zn, Cd, or Hg was studied. A high-resolution dispersion and intensity spectrograph is described. The Hall effect in the plasma of a lamp coutaining Hg vapor in Ar was investigated, Microwave Electronics. A perturbation formula for ferrite-filled cavities is given. A theorem is devised for the small-signal excitation in an electromagnetic system that contains an electron beam or an electron space charge cloud with zero curl of the generalized momentum. Klystron gap theory is further developed by evaluating the gap matrix elements. Atomic Beams. Progress in construction of the apparatus for measuring the velocity of light is reported. Frequency Modulation. The results of a study of the locking and interference suppression characteristics of an oscillating limiter are summarized. The construction and testing of a receiver capable of capturing the weaker of two cochannel FM signals is reported. Statistical Communication Theory. Experiments with a digital probability density analyzer are described in which the second-order probability density of a random process generated by passing the noise output of a gas triode through a narrow-band filter was measured. Stroboscopic Research. Development and use of strobe flash lights for deep sea photography is discussed. Statistical Thermodynamics. Further study of the lambda -line of liquid helium is reported. Progress is
- Research Organization:
- Massachusetts Inst. of Tech., Cambridge. Research Lab. of Electronics
- DOE Contract Number:
- DA36-039-SC-64637
- NSA Number:
- NSA-13-005661
- OSTI ID:
- 4292554
- Report Number(s):
- NP-7107
- Resource Relation:
- Other Information: Project No. 3-99-00-100. Orig. Receipt Date: 31-DEC-59
- Country of Publication:
- United States
- Language:
- English
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