Performance results of the high-gain Nd:glass engineering prototype preamplifier module (PAM) for the National Ignition Facility (NIF)

We describe recent, energetics performance results on the engineering preamplifier module (PAM) prototype located in the front end of the 1.8MJ National Ignition Facility (NIF) laser system. Three vertically mounted subsystem located in the PAM provide laser gain as well as spatial beam shaping. The first subsystem in the PAM prototype is a diode pumped, Nd:glass, linear, TEM{sub 00}, 4.5m long regenerative amplifier cavity. With a single diode pumped head, we amplify a 1nJ, mode matched, temporally shaped ({approx} 20ns) seed pulse by a factor of approximately 10{sup 7} to 20mJ. The second subsystem in the PAM is the beam shaping module, which magnifies the gaussian output beam of the regenerative amplifier to provide a 30mm x 30mm square beam that is spatially shaped in two dimensions to pre-compensate for radial gain profiles in the main amplifiers. The final subsystem in the PAM is the 4-pass amplifier which relay images the 1mJ output of the beam shaper through four gain passes in a {phi}5cm x 48cm flashlamp pumped rod amplifier, amplifying the energy to 175. The system gain of the PAM is 10{sup 10}. Each PAM provides 35 of injected energy to four separate main amplifier chains which in turn delivers 1.8MJ in 192 frequency converted laser beams to the target for a broad range of laser fusion experiments

Early adolescent alcohol abuse in rural northern Michigan

Data concerning several alcohol abuse behaviors were collected from 181 middle school students in Michigan's Upper Peninsula during May, 1982. The findings suggest that alcohol misuse in this region increases significantly with age, and appears to be at rates well above national averages. Examination of gender differences also reveals results which differ from national trends. This paper examines the general alcohol-related abusive behaviors found in this rural youth population, and provides some recommendations for both mental health education program development and therapeutic services.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44302/1/10597_2004_Article_BF00754430.pd

The effect of small versus large group learning on music reading accuracy in the choral classroom.

Includes bibliographical references (p. 31-33).The purpose of this study was to compare the impact of two different modes of instruction (large group and small group learning) on the music reading accuracy of high school choir singers. Participants (n = 63) included members of intermediate and advanced level women's choirs who varied in age, ethnicity, experience, and level of proficiency. For treatment A, large group learning, participants sight read sixteen measures of a piece of music in a large group formation with teacher-led instruction. For treatment B, the participants followed the same procedure with new music in small group formations with student-led instruction. Students were recorded individually while singing within concert formation at the conclusion of each treatment. Results showed significantly higher mean scores for treatment B, small group learning, than for treatment A, large group learning, indicating that small group learning may be a more effective means of improving music reading accuracy.by Melanie J. Braucht.M.M

uv preilluminated gas switches

We have designed, built, and characterized uv preilluminated gas switches for a trigger circuit and a low inductance discharge circuit. These switches have been incorporated into a 54 x 76 x 150 cm pulser module to produce a 1 Ma output current rising at 5 x 10/sup 12/ amps/sec with 1 ns jitter. Twenty such modules will be used on the Nova Inertial Confinement Fusion Laser System for plasma retropulse shutters

High gain preamplifier module (PAM) engineering prototype for the National Ignition Facility (NIF) laser system

We describe recent results and developments in the preamplifier module (PAM) engineering prototype located in NIF� s front end or Optical Pulse Generation (OPG) system. This prototype uses the general laser design developed on a physics testbed and integrates NIP type packaging as well as controls and diagnostics. We will present laser, mechanical and electrical hardware designed and built to date as well as laser energetics measurements

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