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Preliminary evaluation of hermetic JT/LJT/R P connector socket contact design

Description: This report presents a precursory examination of a number of issues pertaining to socket contacts in hermetic connectors. The principal issues addressed are high-contact resistance and contact chatter (circuit discontinuities). Efforts examining the characteristics of the existing socket contact design, the possibility of connector/contact rework, quick-fix solutions, and contact redesigns are summarized.
Date: October 1, 1991
Creator: Baca, J. R. F.
Partner: UNT Libraries Government Documents Department

A method for encapsulating high voltage power transformers

Description: Voltage breakdowns become a major concern in reducing the size of high-voltage power converter transformers. Even the smallest of voids can provide a path for corona discharge which can cause a dielectric breakdown leading to a transformer failure. A method of encapsulating small high voltage transformers has been developed. The method virtually eliminates voids in the impregnation material, provides an exceptional dielectric between windings and provides a mechanically rugged package. The encapsulation material is a CTBN modified mica filled epoxy. The method requires heat/vacuum to impregnate the coil and heat/pressure to cure the encapsulant. The transformer package utilizes a Diallyl Phthalate (DAP) contact assembly in which a coated core/coil assembly is mounted and soldered. This assembly is then loaded into an RTV mold and the encapsulation process begins.
Date: January 1, 1990
Creator: Sanchez, R.O.
Partner: UNT Libraries Government Documents Department

Capattery double layer capacitor life performance

Description: Double layer capacitors (DLCs) have received increased use in computer memory backup applications for consumer products during the past ten years. Their extraordinarily high capacitance density along with their maintenance-free operation makes them particularly suited for these products. These same features also make DLCs very attractive in military type applications. Unfortunately, lifetime performance data has not been reported in the literature for any DLC component. Our objective in this study was to investigate the effects that voltage and temperature have on the properties and performance of single and series-connected DLCs as a function of time. Evans model RE110474, 0.47-farad, 11.0-volt Capatteries were evaluated. These components have a tantalum package, use welded construction, and contain a glass-to-metal seal, all incorporated to circumvent the typical DLC failure modes of electrolyte loss and container corrosion. A five-level, two-factor Central Composite Design'' was used in the study. Single and series-connected Capatteries rated at 85{degree}C, 11.0-volts operation were subjected to test temperatures between 25 and 95{degree}C, and voltages between 0 and 12.9 volts (9 test conditions). Measured responses included capacitance, equivalent series resistance, and discharge time. Data were analyzed using a regression analysis to obtain response functions relating DLC properties to their voltage, temperature, and test time history. These results are described and should aid system and component engineers in using DLCs in critical applications.
Date: January 1, 1991
Creator: Evans, D.A. (Evans Co., East Providence, RI (USA)); Clark, N.H.; Baca, W.E. (Sandia National Labs., Albuquerque, NM (USA)); Miller, J.R. (Miller (John R.), Shaker Heights, OH (USA)) & Barker, T.B. (Rochester Inst. of Tech., NY (USA). Coll. of Engineering)
Partner: UNT Libraries Government Documents Department

Moisture absorption and bakeout characteristics of rigid-flexible multilayer printed wiring boards

Description: Moisture absorption and bakeout characteristics of Allied-Signal Inc., Kansas City Division (KCD) rigid-flexible printed wiring boards were determined. It was found that test specimens had absorbed 0.95 weight percent moisture when equilibrated to a 50 percent RH, 25{degree}C environment. Heating those equilibrated specimens in a 120{degree}C static air oven removed 92 percent of this absorbed moisture in 24 h. Heating the samples in a 80{degree}C static air oven removed only 64 percent of the absorbed moisture at the end of 24 h. A 120{degree}C vacuum bake removed moisture at essentially the same rate with parylene slowed the absorption rate by approximately 50 percent but did not appreciably affect the equilibrium moisture content or the drying rate.
Date: January 1, 1991
Creator: Lula, J.W.
Partner: UNT Libraries Government Documents Department

A Simplified, Improved Method for Making Amplifier Equivalent Noise Charge Measurements Using a New Generation Digitizing Oscilloscope

Description: Historically a variety of methods have been used to measure the equivalent noise charge (ENC) of amplifier/shaper systems for high energy physics. Some of these methods require several pieces of special test equipment and a fair amount of effort. The advent of digitizing oscilloscopes with statistics capabilities makes it possible to perform certain types of noise measurements accurately with very little effort. This paper describes the noise measurement method of a time invariant amplifier/shaper and of a time variant correlated sampling system, using a Tektronix DSA602 Digitizing Signal Analyzer. 4 figs.
Date: October 1990
Creator: Zimmerman, Tom
Partner: UNT Libraries Government Documents Department

Development of a semi-automated workcell for repair of printed circuit boards

Description: Printed circuit boards that comprise US Army electronic systems are repaired at Army depots. An existing automated diagnostic system determines the area of failure; either by identifying failed components or failed board traces. Currently, repairs are performed manually by trained technicians. A system is being developed for repair of through-hole printed circuit boards. It is comprised of many automated and operator-assisted functions to perform the multiple operations related to replacement of failed components. When completed, this system will demonstrate economic payback by reducing skilled labor requirements and decreasing rework. The semi-automated system integrates human operators into the process while maintaining high productivity. After several fully automated systems were conceived and modelled, it was found that the configuration that provided the best return on investment was comprised of a mix of autonomous and operator-assisted functions. 1 ref., 1 fig.
Date: August 1, 1990
Creator: Bennett, D.W. & Evans, M.S.
Partner: UNT Libraries Government Documents Department

Analysis and correction of noise on electronic circuits in an accelerator environment

Description: Accelerator noise sources can cause both analog and digital electronic circuits to malfunction. This paper identifies and analyzes noise sources, and describes the methodology for measurement. Both general remedies and specific solutions to minimize the noise effects on accelerator electronic circuits are described. A policy for electronic design, board layout, assembly, and fabrication is established. Conclusions are drawn based on theoretical principles with practical examples shown in case studies.
Date: January 1, 1992
Creator: Fathizadeh, M.; Despe, O.D. & McGhee, D.G.
Partner: UNT Libraries Government Documents Department

Fiber-optic currents measurements

Description: Polarization maintaining pigtailed laser diodes have greatly increased the ease with which fiber-optic sensors for Faraday current measurements on large pulsed experiments can be deployed. 670, 830, and 1300 nm units are readily available. Such diode lasers can easily be mounted in an RF shielded box along with the simple electronics and batteries to power them. Our units measure 16.5 [times] 8 [times] 6 cm. and have a single external control; an on off switch. They use two 1.5 volt C'' cell batteries. By using an LT1073 chip in the electronics the batteries are an energy source rather than a voltage source. These units can provide 100 mA drive to a LT015MD laser diode so that 1 mW of 830 nm fight exits the fiber pigtail for up to 23 hours with no detectable droop in power. For the sensor element twisted single mode low birefringence fibers are wrapped around the region of interest. The fiber pigtail is fused to the sensor section so changes in alignment are avoided. The light exiting the fiber sensor section is immediately analyzed by a compact, 3 [times] 3.5 [times] 5 cm, bulk optical unit which outputs quadrature optical signals into two multimode fibers leading to detectors in a screen room. The system is thus completely free of ground loops and is as immune to noise as the screen room. These sensors have the usual advantages claimed for them and the all dielectric feature was the original reason for their use on our experiments. The ease of deployment however is not usually cited. On our Pegasus II experiment the need arose for a total current measurement at the main header of the capacitor banks. A single turn of optical fiber was easily strung in a 6.4 m diameter circle and attached to laser and ...
Date: January 1, 1993
Creator: Forman, P.R.; Looney, L.D. & Tabaka, L.J.
Partner: UNT Libraries Government Documents Department

Oxide degradation effects in dry patterning of resist using neutral oxygen beams

Description: Novel processing methods are being studied to address the highly selective and directional etch requirements of the ULSI manufacturing era; neutral molecular and atomic beams are two promising candidates. In this study, the potential of 5 eV neutral atomic oxygen beams for dry development of photoresist is demonstrated for application in patterning of CMOS devices. The patterning of photoresist directly on polysilicon gate layers enables the use of a self-contained dry processing strategy, with oxygen beams for resist etching and chlorine beams for polysilicon etching. Exposure to such reactive low-energy species and to the UV radiation from the line-of-sight, high-density plasma source can, however, after MOSFET gate oxide quality, impacting device performance and reliability. We have studied this processing related device integrity issue by subjecting polysilicon gas MOS structures to exposure treatments similar to those used in resist patterning using low energy oxygen beams. Electrical C-V characterization shows a significant increase in the oxide trapped charge and interface state density upon low energy exposure. I-V and dielectric breakdown characterization show increased low-field leakage characteristics for the same exposure. High-field electron injection studies reveal that the 0.25-V to 0.5-V negative flatband shifts can be partially annealed by the carrier injection. This could be due to positive charge annihilation or electron trapping, or some combination of both. Physical and analysis of patterned resist layers and electrical characterization data of MOS structures exposed to different neutral beam processing environments and following thermal annealing treatments is presented.
Date: January 1, 1992
Creator: Mlynko, W.E.; Kasi, S.R. (International Business Machines Corp., Essex Junction, VT (United States)) & Manos, D. (Princeton Univ., NJ (United States). Plasma Physics Lab.)
Partner: UNT Libraries Government Documents Department

User's manual for the DAD-1 data acquisition daughter board for the SuperCard-2

Description: A detailed description of how to use the DAD-1 data acquisition daughter board is given. The DAD-1 daughter board is used with the SuperCard-2, a VME format processor board manufactured by CSP Inc. that is based on the Intel i860 microprocessor. The daughter board provides high speed acquisition of digital data through a general purpose input port. Data are transferred through direct memory access operations to the memory on the SuperCard-2 board at a rate up to 40 million, 14 bit samples per second. A first-in, first-out memory is used to buffer the data during the transfer. Several different data acquisition operating modes are available that make a combination of a SuperCard-2 processor board and a DAD-1 daughter board suitable for a wide range of real time data analysis and feedback control functions.
Date: May 1, 1993
Creator: Ferron, J.R.
Partner: UNT Libraries Government Documents Department

Variable frequency drive applications guide

Description: Traditionally, fans and pumps have been designed to be capable of handling the maximum demand of the system in which they are installed. However, quite often the actual demand can vary and it can be much lower than the original design capacity. These situations have been corrected in the past through additions of outlet dampers to fans or throttling valves to pumps. While these can be effective and simple controls they severely affect the efficiency of the system. Variable frequency (speed) is the most efficient means of capacity control. The most cost effective method of achieving variable speed capacity control is using AC adjustable frequency drives. AC adjustable frequency controls convert any fixed speed AC motor into an adjustable speed device. Adjusting the speed of a motor, by controlling the frequency of the AC power to that motor, reduces its horsepower requirements. According to pump and fan laws, capacity is proportional to speed while horsepower is proportional to the cube of the speed. Therefore, by reducing the speed of an AC motor by 20 percent the horsepower requirement is reduced by nearly 50 percent. Reduced speed through variable frequency control allows for flexibility of meeting changing weather and comfort requirements without operating costly equipment at full capacity.
Date: October 1, 1991
Creator: Laloudakis, D.J.
Partner: UNT Libraries Government Documents Department

Pulse code modulation data compression for automated test equipment

Description: Development of automated test equipment for an advanced telemetry system requires continuous monitoring of PCM data while exercising telemetry inputs. This requirements leads to a large amount of data that needs to be stored and later analyzed. For example, a data stream of 4 Mbits/s and a test time of thirty minutes would yield 900 Mbytes of raw data. With this raw data, information needs to be stored to correlate the raw data to the test stimulus. This leads to a total of 1.8 Gb of data to be stored and analyzed. There is no method to analyze this amount of data in a reasonable time. A data compression method is needed to reduce the amount of data collected to a reasonable amount. The solution to the problem was data reduction. Data reduction was accomplished by real time limit checking, time stamping, and smart software. Limit checking was accomplished by an eight state finite state machine and four compression algorithms. Time stamping was needed to correlate stimulus to the appropriate output for data reconstruction. The software was written in the C programming language with a DOS extender used to allow it to run in extended mode. A 94--98% compression in the amount of data gathered was accomplished using this method. 1 fig.
Date: May 1, 1991
Creator: Navickas, T.A. & Jones, S.G.
Partner: UNT Libraries Government Documents Department

Ion-optical studies for improved ion transmission in multistage isotope-ratio mass spectrometers

Description: Theoretical and experimental ion-optical studies of multistage isotope-ratio mass spectrometers were conducted to determine what improvement in ion transmission efficiency might be attainable through design changes. The computer program GIOS (General Ion Optical Systems) was used to perform theoretical calculations of focusing properties and ion transmission efficiency. Actual transmission through multiple-sector instruments was determined from measurements of the ion beam vertical profile at the focus of each stage. For existing mass spectrometers with tandem magnets of normal geometry, our studies determined a feasible design change that significantly increases ion transmission through the analyzer. The use of a cylindrical einzel lens or an electrostatic quadrupole lens near the focal point between the magnets provides vertical focusing of the ion beam to achieve the improved transmission. We also established a new mass spectrometer design that give 100% transmission through tandem magnetic analyzers and through a third-stage electrostatic analyzer without the use of an intermediate focusing lens. Non-normal magnetic field boundaries provide ion beam focusing in the vertical plant to achieve this complete transmission. 19 refs., 27 figs., 3 tabs.
Date: October 1, 1991
Creator: Stoffels, J.J. (Pacific Northwest Lab., Richland, WA (United States)) & Laue, H.J. (Purdue Univ., Lafayette, IN (United States))
Partner: UNT Libraries Government Documents Department

Virtual cathode microwave devices -- Basics

Description: Unlike a conventional microwave tube, a virtual-cathode device operates above the space-charge limit where the depth of the space-charge potential can cause electron reflection. The region associated with this electron reflection is referred to as a virtual cathode. Microwaves can be generated through oscillations in the position of the virtual cathode and through the bunching of electrons trapped in a potential well between the real and virtual cathodes. These two mechanisms are competitive. There are three basic classes of virtual cathode devices: (1) reflex triode; (2) reditron and side-shoot vircator; and (3) reflex diode or vircator. The reflex diode is the highest power virtual-cathode device. For the reflex diode the energy exchange between the beam and electromagnetic wave occurs in both the axial and radial directions. In some designs the oscillating-virtual-cathode frequency exceeds the reflexing-electron frequency exceeds the oscillating-virtual-cathode frequency. For the flex diode a periodic disruption in magnetic insulation can modulate the high- frequency microwave power. Overall, particle-in-cell simulation predictions and axial reflex diode experiments are in good agreement. Although frequency stability and phase locking of the reflex diode have been demonstrated, little progress has been made in efficiency enhancement. 58 refs., 11 figs.
Date: January 1, 1991
Creator: Thode, L.E. & Snell, C.M.
Partner: UNT Libraries Government Documents Department

Rise time and recovery of GaAs photoconductive semiconductor switches

Description: Fast rise time applications have encouraged us to look at the rise time dependences of lock-on switching. Our tests have shown rise time and delay effects which decrease dramatically with increasing electric field across the switch and/or optical energy used in activating lock-on. Interest in high repetition rate photoconductive semiconductor switches (PCSS), which require very little trigger energy (our 1.5-cm long switches have been triggered with as little as 20 {mu}J), has also led us to investigate recovery from lock-on. Several circuits have been used to induce fast recovery, the fastest being 30 ns. The most reliable circuit produced a 4-pulse burst of +/{minus} 10-kV pulses at 7 MHz with 100-{mu}J trigger energy per pulse. 11 refs., 10 figs.
Date: January 1, 1990
Creator: Zutavern, F.J.; Loubriel, G.M.; O'Malley, M.W.; McLaughlin, D.L. & Helgeson, W.D.
Partner: UNT Libraries Government Documents Department

Custom electronic subsystems for the Laboratory Telerobotic Manipulator

Description: The National Aeronautics and Space Administration (NASA) Space Station Program presents new opportunities for the application of telerobotic and robotic systems. The Laboratory Telerobotic Manipulator (LTM) is a highly advanced 7 degrees-of-freedom (DOF) telerobotic/robotic manipulator. It was developed and built for the Automation Technology Branch at NASA's Langley Research Center (LaRC) for work in research and to demonstrate ground-based telerobotic manipulator system hardware and software systems for future NASA applications in the hazardous environment of space. The LTM manipulator uses an embedded wiring design with all electronics, motor power, and control and communication cables passing through the pitch-yaw differential joints. This design requires the number of cables passing through the pitch/yaw joint to be kept to a minimum. To eliminate the cables needed to carry each pitch-yaw joint's sensor data to the VME control computers, a custom-embedded electronics package for each manipulator joint was developed. The electronics package collects and sends the joint's sensor data to the VME control computers over a fiber optic cable. The electronics package consist of five individual subsystems: the VME Link Processor, the Joint Processor and the Joint Processor power supply in the joint module, the fiber optics communications system, and the electronics and motor power cabling. 3 refs., 3 figs.
Date: January 1, 1990
Creator: Glassell, R.L.; Butler, P.L.; Rowe, J.C. (Oak Ridge National Lab., TN (USA)) & Zimmermann, S.D. (TeleRobotics International, Inc., Knoxville, TN (USA))
Partner: UNT Libraries Government Documents Department

Strained-layer electronics and optoelectronics

Description: Strained-layer epitaxy involves more than the dislocation-free growth of dissimilar materials: effective strained-layer epitaxy exploits lattice-mismatch-induced strain to fine-tune material properties. This paper describes strained-layer epitaxy and describes its application to electronic and optoelectronic device to improve performance.
Date: January 1, 1990
Creator: Myers, D.R.
Partner: UNT Libraries Government Documents Department

Evaluation of surface analysis methods for characterization of trace metal surface contaminants found in silicon IC manufacturing

Description: A major topic at recent silicon-based integrated circuit (IC) manufacturing symposia is the pursuit of decreased contamination levels. The aim is to remove contamination from both processes and materials. In conjunction with this effort, characterization methods are being pushed to lower and lower detection limits. In this paper, we evaluate surface analysis methods used to determine the concentration of inorganic contamination on unpatterned Si wafers. We compare sampling depths, detection limits, and applicability of each method for use in support of Si IC manufacturing. This comparison is further limited to Fe and Cu which are transition metal contaminants associated with manufacturing yield loss. The surface analysis methods included in this evaluation are: Total Reflection X-Ray Fluorescence (TXRF or TRXRF); Secondary Ion Mass Spectrometry (SIMS); two post-ionization'' methods Surface Analysis by Laser Ionization (SALI) and Sputter Initiated Resonant Ionization Spectroscopy (SIRIS); Heavy Ion Backscattering Spectroscopy (HIBS); and Vapor Phase Phase Decomposition (VPD) based methods Atomic Absorption (VPD-AA) along with VPD-TXRF. Sets of 6 in. Si wafers with concentration levels between 10{sup 9} atoms/cm{sup 2} and 10{sup 12} atoms/cm{sup 2} Fe and Cu were characterized by TXRF, SIMS, SIRIS, and HIBS. This data allows estimation of detection limits (DLs) and relative method accuracy. In Section 1 we describe each surface analysis method and the circumstance under which it would be used to support Si IC manufacturing. The equipment used for this comparison and the 150 mm Si wafer set are described in Section 2. Results from each method are contrasted in Section 3. Finally, a conclusion is presented in Section 4.
Date: January 1, 1991
Creator: Diebold, A.C.; Maillot, P.; Gordon, M.; Baylis, J.; Chacon, J.; Witowski, R. (SEMATECH, Austin, TX (United States)) et al.
Partner: UNT Libraries Government Documents Department

Circular format zig-zag scanning of vidicon tubes

Description: In an effort to increase camera readout speed, we have developed a nonconventional vidicon tube scanning technique. Because all vidicon targets are round, acquiring a full view requires overscanning with a conventional square format scan, resulting in 22% of the video field time wasted. Furthermore, conventional scanning employs horizontal flyback, which for high frame rates can be more than 10% of the total field time. Our nonconventional scanning technique eliminates flyback time by utilizing a triangular waveform rather than a sawtooth for horizontal deflection. This triangle wave is amplitude modulated in order to scan only the (circular) area of interest. The vertical deflection is a staircase ramp, with a step occurring at the end of each horizontal line. This maintains even spacing and a parallel relationship between horizontal lines, as opposed to skewed lines with conventional scans. To display the video ouput, the X-Y monitor must also be driven with these waveforms in order to maintain the correct temporal and spatial position of the video data. Sweep rates of 400 lines in a 1 ms field have been demonstrated. Test results using this technique show a frame time reduction of {approximately}30%, with no loss of resolution or dynamic range, and no increased video bandwidth requirements. 7 figs.
Date: January 1, 1991
Creator: Peterson, C.G. & Simmons, C.M.
Partner: UNT Libraries Government Documents Department

Performance of a new monolithic eight channel charge sensitive preamplifier-shaper

Description: A monolithic eight channel CMOS time-invariant preamplifier/shaper has been designed and built by Chuck Britton of ORNL in collaboration with Ray Yarema and Tom Zimmerman of Fermilab. Each of the eight channels incorporates a charge sensitive preamplifier and two shaping stages. The resultant weighting function is similar to CR-RC{sup 3}. The peaking time is approximately 200 ns, and the charge gain approximately in the range of 50--70 mv/fc. The layout was done on a Tinychip pad frame and the device was fabricated in a 2{mu} P-well process by Orbit. Figure 1 shows the chip layout. The channels are on an 84{mu} pitch to fit on a Tinychip without folding the layout. The design can be easily expanded to a larger number of channels. This paper describes results of tests performed on this device at Fermilab. The tests were done with a bare die which was directly wirebonded to a printed circuit board. This minimizes parasitic effects which can become significant when using large packages. Results may be somewhat different when using the standard 40 pin package. 6 figs.
Date: August 1, 1991
Creator: Zimmerman, T.
Partner: UNT Libraries Government Documents Department

A high performance multi-channel preamplifier ASIC

Description: A new preamplifier ASIC has been designed and built to improve performance of the VTPC (Vertex Time Projection Chamber) at Fermilab's Colliding Detector Facility. Design of the semicustom IC was completed using a Tektronix Quick-Chip 2S bipolar linear array. The ASIC has 6 channels on a chip and provides lower noise, higher gain, lower power, and lower mass packaging than the device which it replaces. Actual performance of the preamplifier was found to match very closely the simulated performance. To reduce the mass of the complete circuit board, bare IC dice were mounted directly on a G-10 substrate using COB (chip on board) techniques. The preamplifier and packaging should be applicable to numerous other systems. 1 ref.
Date: November 1, 1991
Creator: Yarema, R.J.; Zimmerman, T.; Williams, W.; Binkley, M.; Huffman, T. & Wagner, R.
Partner: UNT Libraries Government Documents Department

An approximate HSPICE model for orbit low noise analog bipolar NPN transistors

Description: Vertical bipolar NPN transistors can be fabricated cheaply through MOSIS by using the Orbit 2 um Low Noise Analog CMOS process. The collector is formed from an N-well, the base from a p-base diffusion, and the emitter from an N-diffusion. However, since this is a CMOS process there is no buried layer in the collector. Therefore the collector resistance is quite large. Also, the minimum emitter size is 8 um {times} 8 um, which is substantially larger than many fast bipolar processes. For certain applications, though, such as common base or emitter follower amplifiers, the performance of this transistor may be quite acceptable. However, no AC SPICE model is published for this device. This paper describes a simple approximate measurement method that was used at Fermilab to formulate an HSPICE model for these transistor. This method requires only a fast pulse generator and a good digitizing oscilloscope with an active FET probe for the AC measurements. Model parameters for two transistors of different size are then given. 1 ref., 1 fig.
Date: July 1, 1991
Creator: Zimmerman, T.
Partner: UNT Libraries Government Documents Department

Development of reflective optical systems for XUV projection lithography

Description: We describe two full-field reflective reduction systems (1 cm{sup 2} and 6.25 cm{sup 2} image area) and one scanning system (25 mm x scan length image size) that meet the performance requirements for 0.1-{mu}m resolution projection lithography using extreme-ultraviolet (XUV) wavelengths from 10 to 15 nm. These systems consist of two centered, symmetric, annular aspheric mirrors with 35--40% central obscuration, providing a reduction ratio of 3.3 x. Outstanding features include the remarkably low distortion ({le} 10 nm) over the entire image field and the comparatively liberal tolerances on the mirror radii and alignment. While optimized annular illumination can improve the performance, the required performance can be met with full illumination, thereby allowing a simpler system design. 6 refs., 3 figs., 3 tabs.
Date: January 1, 1991
Creator: Viswanathan, V.K. & Newnam, B.E.
Partner: UNT Libraries Government Documents Department

Summary of the laser working group

Description: The laser working group considered several options to deliver synchronized laser pulses of the required energy to the photocathode and laser triggered switches. These requirements actually decreased during the course of the workshop, and the values finally settled upon (<10 {mu}J in 100 fs at {approximately}250 nm for the photocathode and {approximately}20 mJ in 2 ps near either 250 nm or 1 {mu}m for the switches) were considered to be well within the state of the art. Some development work may be required, however, to provide a system that has the desirable characteristics of stability, ease of use and low maintenance. The baseline concept, which is similar to a number of existing systems, utilizes doubled Nd:YAG-pumped dye oscillator/amplifiers to produce an upconverted picosecond pulse that can be amplified to tens of mJ in a KrF excimer laser. A fraction of the dye oscillator output is also compressed by means of a fiber-grating compressor and further amplified in a dye amplifier before being upconverted to produce the synchronized pulse for the photocathode. 9 refs., 1 fig.
Date: October 1, 1988
Creator: Bigio, I.J.; Kurnit, N.A. (Los Alamos National Lab., NM (USA)); Donaldson, W.R. (Rochester Univ., NY (USA). Lab. for Laser Energetics); Geissler, K. (European Organization for Nuclear Research, Geneva (Switzerland)) & Srinivasan-Rao, T. (Brookhaven National Lab., Upton, NY (USA))
Partner: UNT Libraries Government Documents Department