The Fermi National Accelerator Laboratory FERMILAB- TM- 1834 Fermi National Accelerator Laboratory This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. This manuscript has been authored by Universities Research Association, Inc. under con- tract No. DE- ACO% 76CH03000 with the U. S. Department of Energy. The United States Government and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a nonexclusive, paid- up, irrevocable, worldwide license to publish or reproduce the published …

This report is a brief description of a model electron beam, which is meant to serve as a pulsed heat source that vaporizes a metal fleck into an ''under-dense'' cloud. See Reference 1. The envelope of the electron beam is calculated from the paraxial ray equation, as stated in Reference 2. The examples shown here are for 5 A, 200 keV beams that focus to waists of under 0.4 mm diameter, within a cylindrical volume of 10 cm radius and length. The magnetic fields assumed in the examples are moderate, 0.11 T and 0.35 T, and can probably be created by permanent magnets.

Large eddy simulation (LES) is a numerical simulation method for turbulent flows and is derived by spatial averaging of the Navier-Stokes equations. In contrast with the Reynolds-averaged Navier-Stokes equations (RANS) method, LES is capable of calculating transient turbulent flows with greater accuracy. Application of LES to differing flows has given very encouraging results, as reported in the literature. In recent years, a dynamic LES model that presented even better results was proposed and applied to several flows. This report reviews the LES method and its implementation in the COMMIX code, which was developed at Argonne National Laboratory. As an example of the application of LES, the flow around a square prism is simulated, and some numerical results are presented. These results include a three-dimensional simulation that uses a code developed by one of the authors at the University of Notre Dame, and a two-dimensional simulation that uses the COMMIX code. The numerical results are compared with experimental data from the literature and are found to be in very good agreement.

This reports summarizes the technical progress achieved during the third quarter of the ERIP project entitled, ''Laser Ultrasonic Furnace Tube Coke Monitor.'' The focus of work during this reporting period was the construction of an automated probe that will be used to measure the thickness of coke deposits in thermal cracking furnaces. A discovery was made during the last reporting period, which indicated that a conventional NDE broadband transducer could be used in conjunction with a sacrificial standoff composed of a fusible alloy to efficiently couple the transducer to a rough surface operating at high temperature. A probe was constructed that incorporates the recent discovery and initial testing of the probe is now underway. Because of other project commitments, the manpower available to allocate to the coke detector project was limited during the most recent quarter. As a result, the project is somewhat behind the original schedule. However, project expenditures are consistent with the project progress to date. The total program budget is $98,670 and the current project expenditures are approximately $24,000. The original contract budget period ends on April 30, 1999. We intend to request a six-month no-cost extension to the contract so that we may complete the project …

The focus of work during this reporting period was the construction of an automated probe that will be used to measure the thickness of coke deposits in thermal cracking furnaces. A discovery was made during the last reporting period, which indicated that a conventional NDE broadband transducer could be used in conjunction with a sacrificial standoff composed of a fusible alloy to efficiently couple the transducer to a rough surface operating at high temperature. A probe was constructed that incorporates the recent discovery and initial testing of the probe is now underway. Successful development of the coke detector will provide industry with the only available method for on-line measurement of coke deposits. The coke detector will have numerous uses in the refining and petrochemical sectors including monitoring of visbreakers, hydrotreaters, delayed coking units, vacuum tower heaters, and various other heavy oil heating applications where coke formation is a problem.