15 KJ FLASH LAMP, POWER CONDITIONING UNIT DESIGNED FOR SAFTY, RELIABILITY & MANUFACTURABILITY*

A 15kJoule, Flash Lamp Power Conditioning Unit has been successfully designed, developed, and deployed in the National Ignition Facility (NIF) Preamplifier Modules (PAM). The primary design philosophy of this power conditioning unit (PCU) is safety, reliability, and manufacturability. Cost reduction over commercially equivalent systems was also achieved through an easily manufactured packaging design optimized to meet NIF requirements. While still maintaining low cost, the PCU design includes a robust control system, fault diagnostic system, and safety features. The pulsed power design includes 6 PFN modules, each including a dual series injection trigger transformer, that drive a total of 12 flash lamp loads. The lamps are individually triggered via a 20kV pulse produced by a 1kV, MCT switched capacitive discharge unit on the primary side of the trigger transformer. The remote control interface includes an embedded controller that captures flash lamp current wave forms and fault status for each shot. The embedded controller provides the flexibility of remotely adjusting both the main drive voltage from 1.6 to 2.5 kV and the trigger voltage from 0 to 20 kV

Halbach array motor/generators: A novel generalized electric machine

In August 1979, Halbach submitted a paper entitled ``Design of Permanent Multipole Magnets with Oriented Rare Earth Cobalt Material.`` In this paper, he presented a novel method of generating multipole magnetic fields using non-intuitive geometrical arrangements of permanent magnets. In subsequent publications, he further defined these concepts. Of particular interest to one of the authors (RFP) was the special magnet array that generated a uniform dipole field. In 1990 Post proposed the construction of an electric machine (a motor/generator) using a dipole field based on Klaus Halbach`s array of permanent magnets. He further proposed that such a system should be employed as an integral part of ``an electromechanical battery`` (EMB), i.e., a modular flywheel system to be used as a device for storing electrical energy, as an alternative to the electrochemical storage battery. This paper reviews Halbach`s theory for the generation of a dipole field using an array of permanent magnet bars, presents a simple analysis of a family of novel ``ironless`` electric machines designed using the dipole Halbach array, and describes the results obtained when they were tested in the laboratory

Development of a theoretical-practical script for clinical simulation

Abstract OBJECTIVE To develop a theoretical-practical script based on the opinion of experts to be used in simulated clinical activities. METHOD Qualitative study through analysis of content of interviews with experts on the theme in order to develop the proposed script. Of the 24 invited experts, 12 specialists from educational institutions in Brazil and abroad participated in the study in compliance with the ethical precepts. The experts responded to questions on the characterization of their study attributes and described the items required for the development of a simulated scenario. In view of the responses obtained, data content was analyzed and classified into units and subunits of significance. RESULTS The items mentioned for the development of the script generated seven units of significance. The units and subunits of significance were gathered in three stages of the main components of the simulated scenario: prior, preparation, and finals. CONCLUSION This study enables an innovative, stimulating teaching experience, making it easier for professors to use the simulation resource as a learning process in an effective and objective manner, as a guide to professors and researchers in the area of clinical simulation

Lawson criterion for ignition exceeded in an inertial fusion experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion

Development system performance issues of the NIF master oscillator and pulse forming networking

A crucial step in the development of a complex laser system is initial testing of an integrated system. Issues arise at the system level which are not easily observed in component level testing. The NIF master oscillator room (MOR) contains a network of fiber and integrated optic components which can interact, potentially reducing system performance. Here we present some of the system problems we have seen in integrated tests and our solutions. Issues include ASE in the fiber amplifiers, filtering effects in the PM fiber, and regulation of average optical power

Case Study of the Failure of two 13.8kV Control & Metering Transformers that caused significant Equipment Damage

The degradation and failure of cast-coil epoxy windings within 13.8kV control power transformers and metering potential transformers has been shown to be dangerous to both equipment and personnel, even though best industrial design practices were followed. Accident scenes will be examined for two events at a U.S. Department of Energy laboratory. Failure modes will be explained and current design practices discussed with changes suggested to prevent a recurrence and to minimize future risk. New maintenance philosophies utilizing partial discharge testing of the transformers as a prediction of end-of-life will be examined

Optical pulse generation system for the National Ignition Facility (NIF)

We describe the Optical Pulse Generation (OPG) system for the National Ignition Facility ( NIF ). The OPG system begins with the Master Oscillator Room ( MOR ) where the initial, seed pulse for the entire laser system is produced and properly formatted to enhance ignition in the target. The formatting consists of temporally shaping the pulse and adding additional bandwidth to increase the coupling of the laser generated x-rays to the high density target plasma. The pulse produced in the MOR fans out to 48 identical preamplifier modules where it is amplified by a factor of ten billion and spatially shaped for injection into the 192 main amplifier cha