The following document describes the usage of the LRL 9-ZOOM code, a neutron diffusion theory reactor code for the IBM 709. The code has been modified to solve configuration of a series of stacked cylindrical disks, designating a new geometry case.

"Short-range order coefficients were measured at 300 and 400°C for iron-aluminum alloys containing 14.8, 18.2, and 20.0 atomic per cent aluminum. These alloys exhibited a strong preference for unlike near neighbors. The short-range order was greater at the lower temperature and increased as the Fe 3Al composition was approached."

"This report is concerned with the effectiveness of this washback procedure in reducing the phosphate concentration and also with other methods by which the simultaneous extraction of phosphate along with tuballoy may be minimized."

Applications of sheathed (metal) thermocouples may require in many instances, the insertion of the thermocouple thermal junction into an area that must be hermetically sealed to the outside. This same area usually contains highly reactive heat transfer medium such as an eutectic alloy of sodium and potassium of sodium alone. When fissionable materials are being irradiated, fission products that are driven off would also be present and must be contained under varying temperatures and pressures.

Describes the investigation of a particular method of extracting ions from an arc. Experimental results of a low extraction voltage ion source are given in some detail.

The Plutonium Recycle Test Reactor is heavy water moderated with a heavy or light water reflector contained by a complex aluminum vessel called a Calandria. ( See Figure 1). Construction of this vessel started in August, 1958, at a large West Coast vendor's plant and was completed at Hanford in December, 1959. The fabrication problems associated with a high integrity welded aluminum vessel were generally unrealized prior to this period. This report covers the fabrication of the Calandria and lists recommendations for improving the design and reducing the cost.

The dependence of the resonance integral for thorium upon geometry and thorium temperature has been determined through reactivity coefficient measurements performed in the Hanford Test Pile. The geometry dependence was investigated using thorium cylinders of various diameters in the form of solid elements and shells. The temperature dependence (Doppler broadening) was studied by heating thorium elements and permitting them to cool while observing the change in pile reactivity.

This semiannual progress report and future reports will be published as two documents to permit a wider distribution of the unclassified material. The report numbers are assigned in sequence so that the two reports will fall together when filed by report number.

"Theoretical calculations have been carried our for the two ordering phases which occur in the FeAl system. The statistical treatment involves first and second neighbor interaction parameters as well as a magnetic interaction between first neighbor iron atoms. The phase diagram and the amount and type of long range order for slowly cooled alloys are calculated. Further calculations include short range order for the disordered phase at three compositions and two temperatures. As expected, the short range order increases as a critical temperature is approached either in composition of in temperature."