Lawrence Livermore National Laboratory, Procurement & Materiel, L-650, P.O. Box 5012, Livermore, CA 94551

59 -- DEVELOPMENT AND FABRICATION OF ULTRASONIC SENSORS FOR LASER DAMAGE IN LARGE APERTURE OPTICS POC Eileen Nasto, Contract Administration Specialist, 925-422-2412 E-MAIL: Click here to contact the contracting officer via, nasto1@llnl.gov. The University of California, as Management & Operations contractor for Lawrence Livermore National Laboratory (LLNL), under the US Department of Energy (DOE) is soliciting expressions of interest for development and fabrication of ultrasonic sensor arrays for monitoring laser damage in large aperture optics used by the National Ignition Facility (NIF) project. The NIF project will provide a facility that is capable of achieving fusion ignition utilizing solid-state lasers as the energy driver. In the NIF facility, a large number of lasers will be focused onto a small target located in the center of a spherical vacuum chamber; the energy from the lasers will be delivered simultaneously, and within a few billionths of a second. The target will then implode, forcing atomic nuclei to sufficiently high temperature and density to achieve a fusion reaction. Additional information about the NIF project can be found at http://lasers.llnl.gov/laser.nif.html. During normal operation of the system, the high energy lasers will induce and grow damage on the (nominally) 4.5 cm thick windows into the vacuum target chamber. It is desirable to diagnose and monitor damage at or exceeding approximately 1 mm so that the optics can be removed and reconditioned when the largest damage sites reach 2-3 mm. Initial feasibility studies indicate that the required sensitivity levels (1 mm diameter pits) can be reached with 5 MHz ultrasonic probes. Implementation of a system must accommodate several technical and environmental aspects particular to the application. Because the optical components being inspected are windows for high energy laser beams, access for the ultrasonic probes is only feasible at the edges. Essentially the entire 45 x 45 cm vacuum-side surface must be interrogated. In other words, the system must find a 1 mm defect anywhere on the surface. Received ultrasonic signals must be suitable for locating and sizing the defects of interest. Electronics and signal processing are being developed at LLNL. Access for transducers to two adjacent sides of the square windows is feasible. The other two sides (edges) are inaccessible. The use of surface waves for this application is unlikely due to the large force applied on the polymeric vacuum gasket at the window/vacuum interface. This gasket serves to damp any surface acoustic waves generated at the window edges. The transducers may be subjected to significant levels of gamma rays and high energy neutrons. Survivability testing to determine radiation hardness will be performed by LLNL. A significant consideration in the development of the system is cost. Due to the multiplicity of the system, ~200 vacuum windows must be fitted with sensors. Each of these windows is approximately 2000 cm2, and there is a tradeoff between cost and the number of transducer elements. This tradeoff is amplified by cable costs which can become significant for a large number of transducers. Cable costs are significant because electronics will be located ~ 200 feet away due to space limitations and potential radiation exposure. The vacuum optics are highly sensitive to contamination (i.e. debris) and must be kept clean during application of the transducer arrays. The arrays, therefore, must be amenable to cleaning to Class 100 cleanroom standards (per Fed. Std. 209E). A typical task would be to produce the first article of a prototype transducer array. After testing and validation, a decision will be made by LLNL as to whether a procurement for production is to be undertaken. Production awards may be negotiated or competed. It is anticipated that only those companies selected for the award of the initial task will be asked to compete for production quantities. However, selection for the initial task does not constitute any guarantee that a subsequent procurement will be initiated. While design engineering is not expected to be a major portion of the overall effort, the University anticipates some tasks will include design finalization. For example, reviewing and revising design packages for completeness, compatibility with existing infrastructure/processes, and cost-effectiveness. Interested candidates are invited to respond with an expression of interest which should include a brief description (no more than 10 pages including attachments) of proposed transducer array configurations. Candidates must demonstrate qualifications with respect to the following areas of expertise: limited-run production of custom transducer systems; a proven track record of interaction with research institutions; and field deployment of on-line UT monitoring systems. In addition, suitable facilities and manufacturing staff, with ability to rapidly convert to new efforts and a supplier management program supported by an ISO-9001-level quality program are important. Do not send standard company brochures or photographs. Expressions of interest are to assist the University in determining the potential for competition among qualified and interested candidates. The actual solicitations for award are not yet available. This notice is intended to serve as the only notification of these requirements. Expressions of interest are due on or before 4/15/00. Facsimile and telephone responses will not be accepted. Hand delivered/ overnight submissions may be sent to 7000 East Avenue, Livermore, CA 94550. Posted 03/21/00 (W-SN436776). (0081)

Loren Data Corp. http://www.ld.com (SYN# 0242 20000323\59-0017.SOL)