Spectroscopic determination of C{sub 2} in Ar/H{sub 2}/CH{sub 4} and Ar/H{sub 2}/C{sub 60} microwave plasmas for nanocrystalline diamond synthesis. (open access)

Spectroscopic determination of C{sub 2} in Ar/H{sub 2}/CH{sub 4} and Ar/H{sub 2}/C{sub 60} microwave plasmas for nanocrystalline diamond synthesis.

We have measured the steady state concentration of gas phase C{sub 2} in Ar/H{sub 2}/CH{sub 4} and Ar/H{sub 2}/C{sub 60} microwave plasmas used for the deposition of nanocrystalline diamond films. High sensitivity white light absorption spectroscopy is used to monitor the C{sub 2} density using the d{sup 3}II {l_arrow} A{sup 3}II (0,0) vibrational band of C{sub 2} as chamber pressure, microwave power, substrate temperature and feed gas mixtures are varied in both chemistries. Understanding how these parameters influence the C{sub 2} density in the plasma volume provides insight into discharge mechanisms relevant to the deposition of nanocrystalline diamond.
Date: February 5, 1998
Creator: Goyette, A. N.; Lawler, J. E.; Anderson, L. W.; Gruen, D. M.; McCauley, T. G.; Zhou, D. et al.
System: The UNT Digital Library
Characterization of fluence limiting defects in hafnia/silica multilayer coatings manufactured for the National Ignition Facility (open access)

Characterization of fluence limiting defects in hafnia/silica multilayer coatings manufactured for the National Ignition Facility

A variety of microscopic techniques are employed to characterize fluence limiting defects in hafnia/silica multilayer coatings manufactured for the National Ignition Facility.
Date: February 5, 1998
Creator: Wu, Z. L., LLNL
System: The UNT Digital Library
Applied ALARA techniques (open access)

Applied ALARA techniques

The presentation focuses on some of the time-proven and new technologies being used to accomplish radiological work. These techniques can be applied at nuclear facilities to reduce radiation doses and protect the environment. The last reactor plants and processing facilities were shutdown and Hanford was given a new mission to put the facilities in a safe condition, decontaminate, and prepare them for decommissioning. The skills that were necessary to operate these facilities were different than the skills needed today to clean up Hanford. Workers were not familiar with many of the tools, equipment, and materials needed to accomplish:the new mission, which includes clean up of contaminated areas in and around all the facilities, recovery of reactor fuel from spent fuel pools, and the removal of millions of gallons of highly radioactive waste from 177 underground tanks. In addition, this work has to be done with a reduced number of workers and a smaller budget. At Hanford, facilities contain a myriad of radioactive isotopes that are 2048 located inside plant systems, underground tanks, and the soil. As cleanup work at Hanford began, it became obvious early that in order to get workers to apply ALARA and use hew tools and equipment …
Date: February 5, 1998
Creator: Waggoner, L. O.
System: The UNT Digital Library
ALARA Center of Technology -- resource guide (open access)

ALARA Center of Technology -- resource guide

The purpose is to provide a source of information that can be used to assist personnel in the planning, training, and execution of radiological work using the principles of ALARA. This document is not intended to replace HNF or WHC Control Manual requirements. The ALARA Tools-List provides detailed information on the use and procurement of engineered controls, mockup training guidelines, and good radiological work practices that have been proven to be ALARA.
Date: February 5, 1998
Creator: Waggoner, L. O.
System: The UNT Digital Library