Resource Type

National Ignition Facility Target Chamber (open access)

National Ignition Facility Target Chamber

On June 11, 1999 the Department of Energy dedicated the single largest piece of the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) in Livermore, California. The ten (10) meter diameter aluminum target high vacuum chamber will serve as the working end of the largest laser in the world. The output of 192 laser beams will converge at the precise center of the chamber. The laser beams will enter the chamber in two by two arrays to illuminate 10 millimeter long gold cylinders called hohlraums enclosing 2 millimeter capsule containing deuterium, tritium and isotopes of hydrogen. The two isotopes will fuse, thereby creating temperatures and pressures resembling those found only inside stars and in detonated nuclear weapons, but on a minute scale. The NIF Project will serve as an essential facility to insure safety and reliability of our nation's nuclear arsenal as well as demonstrating inertial fusion's contribution to creating electrical power. The paper will discuss the requirements that had to be addressed during the design, fabrication and testing of the target chamber. A team from Sandia National Laboratories (SNL) and LLNL with input from industry performed the configuration and basic design of the target chamber. The method …
Date: October 5, 2000
Creator: Wavrik, R W; Cox, J R & Fleming, P J
System: The UNT Digital Library
Induction Accelerator Efficiency at 5 Hz (open access)

Induction Accelerator Efficiency at 5 Hz

We simulate fusion power plant driver efficiency by pulsing small induction cores at 5 Hz (a typical projected power plant repetition rate), with a resistive load in the secondary winding that is scaled to simulate the beam loading for induction acceleration. Starting from a power plant driver design that is based on other constraints, we obtain the core mass and acceleration efficiency for several energy ranges of the driver accelerator and for three magnetic alloys. The resistor in the secondary is chosen to give the same acceleration efficiency, the ratio of beam energy gain to energy input to the core module (core plus acceleration gap), as was computed for the driver. The pulser consists of a capacitor switched by FETs, Field Effect Transistors, which are gated on for the desired pulse duration. The energy to the resistor is evaluated during the portion of the pulse that is adequately flat. We present data over a range of 0.6 to 5 {mu}s pulse lengths. With 1 {mu}s pulses, the acceleration efficiency at 5 Hz is measured to be 75%, 52%, and 32% for thin-tape-wound cores of nanocrystalline, amorphous, and 3% silicon steel materials respectively, including only core losses. The efficiency increases for …
Date: October 5, 2000
Creator: Molvik, A.W. & Faltens, A.
System: The UNT Digital Library
Biocavity Lasers (open access)

Biocavity Lasers

Laser technology has advanced dramatically and is an integral part of today's healthcare delivery system. Lasers are used in the laboratory analysis of human blood samples and serve as surgical tools that kill, burn or cut tissue. Recent semiconductor microtechnology has reduced the size o f a laser to the size of a biological cell or even a virus particle. By integrating these ultra small lasers with biological systems, it is possible to create micro-electrical mechanical systems that may revolutionize health care delivery.
Date: October 5, 2000
Creator: Gourley, P. L. & Gourley, M. F.
System: The UNT Digital Library
A New 500-kV Ion Source Test Stand for HIF (open access)

A New 500-kV Ion Source Test Stand for HIF

One of the most challenging aspects of ion beam driven inertial fusion energy is the reliable and efficient generation of low emittance, high current ion beams. The primary ion source requirements include a rise time of order 1-msec, a pulse width of at least 20-msec, a flattop ripple of less than 0.1% and a repetition rate of at least 5-Hz. Naturally, at such a repetition rate, the duty cycle of the source must be greater than 108 pulses. Although these specifications do not appear to exceed the state-of-the-art for pulsed power, considerable effort remains to develop a suitable high current ion source. Therefore, we are constructing a 500-kV test stand specifically for studying various ion source concepts including surface, plasma and metal vapor arc. This paper will describe the test stand design specifications as well as the details of the various subsystems and components.
Date: October 5, 2000
Creator: Sangster, T. C.; Ahle, L. E.; Halaxa, E. F.; Karpenko, V. P.; Oldaker, M. E.; Mitchell, J. W. et al.
System: The UNT Digital Library
Intense muon beams and neutrino factories (open access)

Intense muon beams and neutrino factories

High intensity muon sources are needed in exploring neutrino factories, lepton flavor violating muon processes, and lower energy experiments as the stepping phase towards building higher energy {mu}{sup +}{mu}{sup {minus}} colliders. We present a brief overview, sketch of a neutrino source, and an example of a muon storage ring at BNL with detector(s) at Fermilab, Sudan, etc. Physics with low energy neutrino beams based on muon storage rings ({mu}SR) and conventional Horn Facilities are described and compared. CP violation Asymmetries and a new Statistical Figure of Merit to be used for comparison is given. Improvements in the sensitivity of low energy experiments to study Flavor changing neutral currents are also included.
Date: October 5, 2000
Creator: Parsa, Z.
System: The UNT Digital Library
Photonic Bandgap Waveguides - 2D PBG Materials Embedded in a GaAs/AlO Slab (open access)

Photonic Bandgap Waveguides - 2D PBG Materials Embedded in a GaAs/AlO Slab

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Date: October 5, 2000
Creator: Chow, E.; Lin, S. Y.; Wendt, J. R.; Allerman, A. A.; Vawter, G. A.; Zubrzycki, W. J. et al.
System: The UNT Digital Library
Molecular Dynamics Simulations of Collisional Cooling and Ordering of Multiply Charged Ions in a Penning Trap (open access)

Molecular Dynamics Simulations of Collisional Cooling and Ordering of Multiply Charged Ions in a Penning Trap

Molecular dynamics simulations are used to help design new experiments by modeling the cooling of small numbers of trapped multiply charged ions by Coulomb interactions with laser-cooled Be{sup +} ions. A Verlet algorithm is used to integrate the equations of motion of two species of point ions interacting in an ideal Penning trap. We use a time step short enough to follow the cyclotron motion of the ions. Axial and radial temperatures for each species are saved periodically. Direct heating and cooling of each species in the simulation can be performed by periodically rescaling velocities. Of interest are Fe{sup 11+} due to a EUV-optical double resonance for imaging and manipulating the ions, and Ca{sup 14+} since a ground state fine structure transition has a convenient wavelength in the tunable laser range.
Date: October 5, 2000
Creator: Holder, J. P.; Church, D. A.; Gruber, L.; DeWitt, H. E.; Beck, B. R. & Schneider, D.
System: The UNT Digital Library