In solving the two-group, two medium equations for neutron diffusion in a finite one-dimensional multiplying system, the equations in each medium can be solved, and the boundary conditions used to determine the coefficients. This direct attack involves eight simultaneous linear equations. The opportunities for error are numerous, and, frequently, a great deal of accuracy is lost by subtractions; hence, it is felt that an alternative method of solution, in which numerical errors would be less likely to occur, would be desirable.

Summary of research progress meetings of October 2 and October 9, 1952: High speed high vacuum ion pump, High energy ion irradiation, Space charge accelerator for protons, Availability of the [ ] meson beam at the cyclatron, Effect of chemical structure on stopping powers for high energy protons.

The instrument (polychromator) described observes time-dependent spectral-line profiles by simultaneous measurement at nine different wavelengths of light intensity as a function of time. A cylindrical lens magnifies the dispersion of a Jarrell-Ash Model S2000 Ebert Monochromator and forms an image on a light-pipe solder. Light pipes transfer light from various sections of the image--i.e., different wavelengths--to photomultiplier tubes, and the responses are displayed on oscilloscopes. The instrument has been used to look at total wavelength spans of 15 A and 20 A.