Several spectroscopic methods are discussed that use core levels, such as photoelectron spectroscopy and absorption spectroscopy with photoelectron or fluorescence detection. Measurements are presented on the desorption of a chemical oxide and the growth of oxynitrides with N{sub 2}0 on Si(100). The stoichiometry is found to change strongly with thickness, from a nitrogen-terminated Si surface to a nearly-pure oxide in the outer region of 40--60 {Angstrom} films. Using a third generation synchrotron beam line a sensitivity of better than a tenth of a monolayer is achieved by a simple photocurrent measurement.

Colloidal suspensions of oxides have been used to prepare dielectric HR (high reflective) mirrors, specifically for high power fusion case applications, on substrates up to 38 cm square using a meniscus coater. These coatings consist of porous quarterwave layers of alternating high and low refractive index oxides. Silica was used as the low index oxide and AlOOH, ZrO{sub 2}, or HfO{sub 2} as the high index material. Coatings were weak because of low particle-to-particle adhesion. Use of organic polymer binders in the high index component was found to increase strength, thereby improving the laser damage threshold and also reducing the number of layers required for 99% reflection due to increased refractive index.

A new code is being developed at the Y-12 Plant for solving the time-dependent, three-dimensional Boltzmann transport model with feedback. The new code, PADK, uses the quasi-static method in its adiabatic form and is to be utilized to analyze hypothetical criticality accidents. A description of the code along with preliminary results without feedback are presented in this paper. The code is applied to 2 standard benchmark problems and the results are compared to another method. Also, the code is used to model the GODIVA reactor. Further work needed to be completed is described.