Recueil 102, 11 pièces PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Recueil 102, 11 pièces PDF full book. Access full book title Recueil 102, 11 pièces by . Download full books in PDF and EPUB format.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 15
Get Book Here
Book Description
The preliminary design of the target area for the National Ignition Facility has been completed. The target area is required to meet a challenging set of engineering system design requirements and user needs. The target area must provide the appropriate conditions before, during, and after each shot. The repeated introduction of large amounts of laser energy into the chamber and subsequent target emissions represent new design challenges for ICF facility design. Prior to each shot, the target area must provide the required target illumination, target chamber vacuum, diagnostics, and optically stable structures. During the shot, the impact of the target emissions on the target chamber, diagnostics, and optical elements is minimized and the workers and public are protected from excessive prompt radiation doses. After the shot, residual radioactivation is managed to allow the required accessibility. Diagnostic data is retrieved, operations and maintenance activities are conducted, and the facility is ready for the next shot. The target area subsystems include the target chamber, target positioner, structural systems, target diagnostics, environmental systems, and the final optics assembly. The engineering design of the major elements of the target area requires a unique combination of precision engineering, structural analysis, opto-mechanical design, random vibration suppression, thermal stability, materials engineering, robotics, and optical cleanliness. The facility has been designed to conduct both x- ray driven targets and to be converted at a later date for direct drive experiments. The NIF has been configured to provide a wide range of experimental environments for the anticipated user groups of the facility. The design status of the major elements of the target area is described.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
A description of Target Area systems performance shows that the target area conceptual design can meet its performance criteria. Before the shot, the target area provides a vacuum of 5 [times] 10[sup [minus]5] Torr within 2 hours. A target, cryogenic or non-cryogenic, is placed to within 1 cm of chamber center with a positioner that minimizes vibration of the target. The target is then aligned to [le] 7 [mu]m by using the Target Alignment Sensor (TAS) system. The viewers in this system will also determine if the target is ready for illumination. Diagnostics are aligned to the necessary specifications by the alignment viewers. The target is shot and data is collected. Nearly all tritium (if present) is passed through the vacuum system and into the collection system. The analysis that supports the target area design basis is a combination of careful assumptions, data, and calculations. Some uncertainty exists concerning certain aspects of the source terms for x-rays and debris, material responses to this energy flux, and the full consequences of the material responses that do occur. For this reason, we have selected what we believe are conservative values in these areas. Advanced conceptual design activities will improve our understanding of these phenomena and allow a more quantitative assessment of the degree of conservatism inherent to the system. However, the results of this preliminary survey of target area operations indicate an annual shot rate of 600 (for the mix of shots shown in Table 1) is feasible for this set of target area systems.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 6
Get Book Here
Book Description
The National Ignition Facility (NIF) is a proposed Department of Energy facility which will contribute to the resolution of important Defense Program and inertial fusion energy issues for energy production in the future. The NIF will consist of a laser system with 192 independent beamlets transported to a target chamber. The target chamber is a multi-purpose structure that provides the interface between the target and the laser optics. The chamber must be capable of achieving moderate vacuum levels in reasonable times; it must remain dimensionally stable within micron tolerances, provide support for the optics, diagnostics, and target positioner; it must minimize the debris from the x-ray and laser light environments; and it must be capable of supporting external neutron shielding. The chamber must also be fabricated from a low activation material. The fusion reaction in the target gives off neutrons, x-ray and gamma rays. The x-rays and gamma rays interact with the interior of the target chamber wall while neutrons penetrate the wall. In order to minimize the neutron activation of components outside the target chamber and to absorb gammas emitted from the activated chamber, shielding will be placed immediately outside the chamber. The target chamber contains the target positioner. The target positioner moves the target from outside the chamber to the center of the chamber and positions the target at the focal spot of the laser beams. The target positioner must be survivable in a harsh radioactive environment. The materials used must be low activation and have a high stiffness to weight ratio to maintain target stability. This paper describes the conceptual design of the target chamber, target postioner, and shielding for the NIF.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 8
Get Book Here
Book Description
This is a brief update on the work being done to design ignition targets for the National Ignition Facility. Updates are presented on three areas of current activity : improvements in modeling, work on a variety of targets spanning the parameter space of possible ignition targets ; and the setting of specifications for target fabrication and diagnostics. Highlights of recent activity include : a simulation of the Rayleigh-Taylor instability growth on an imploding capsule, done in 3D on a 72° by 72° wedge, with enough zones to resolve modes out to 100 ; and designs of targets at 250eV and 350eV, as well as the baseline 300 eV ; and variation of the central DT gas density, which influences both the Rayleigh-Taylor growth and the smoothness of the DT ice layer.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 117
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 5
Get Book Here
Book Description
The Target Area Structural Support (TASS) systems are designed to provide an optically stable support for the target area systems and personnel access platforms for the 192 laser beam configuration. The conceptual design of the TASS systems was an optimum configuration selected from three designs on which performance studies were conducted. The supporting bases for the design selection were the analytical results, operation, and cost effective.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 8
Get Book Here
Book Description
The Department of Energy (DOE) is proposing to construct the National Ignition Facility (NIF) to embark on a program to achieve ignition and modest gain in the laboratory. With annual fusion yields of up to 1200 MJ/year, neutron activation of nearby components is an important issue. Calculations must be performed to ensure that Target Area structures are designed and activities are planned in a way that ensures that such activities can be completed at the required times while meeting all requirements for occupational exposure to radiation. These calculations are referred to as {open_quotes}Lime-motion{close_quotes} studies. In the present work, key Target Area activities are identified and a detailed time-motion study has been completed for the task of debris shield change-out. Results of a preliminary time-motion study for debris shield change-out were used to influence the design. Subsequent analyses have been completed for several point designs of the NIF Final Optics Assembly (FOA). For each FOA point design, a total annual occupational dose equivalent, in person-Sv, has been estimated. Estimates range from 0.19 person-Sv/year (19 person-rem/year) for a composite FOA with a polyethylene plug to 1.38 person-Sv/year (138 person-rem/year) for the baseline FOA design.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
One of the major goals of the US National Ignition Facility is the demonstration of laser driven fusion ignition and burn of targets by inertial confinement and provide capability for a wide variety of high energy density physics experiments. The NIF target area houses the optical systems required to focus the 192 beamlets to a target precisely positioned at the center of the 10 meter diameter, 10-cm thick aluminum target chamber. The chamber serves as mounting surface for the 48 final optics assemblies, the target alignment and positioning equipment, and the target diagnostics. The internal surfaces of the chamber are protected by louvered steel beam dumps. The target area also provides the necessary shielding against target emission and environmental protection equipment. Despite its complexity, the design provides the flexibility to accommodate the needs of the various NIF user groups, such as direct and indirect drive irradiation geometries, modular final optics design, capability to handle cryogenic targets, and easily re-configurable diagnostic instruments. Efficient target area operations are ensured by using line-replaceable designs for systems requiring frequent inspection, maintenance and reconfiguration, such as the final optics, debris shields, phase plates and the diagnostic instruments. A precision diagnostic instrument manipulator (DIMS) allows fast removal and precise repositioning of diagnostic instruments. In addition the authors describe several activities to enhance the target chamber availability, such as the target debris mitigation, the use of standard experimental configurations and the development of smart shot operations planning tools.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
NIF will be configured in its baseline design to achieve ignition and gain using the indirect drive approach. However, the requirements require the design to not preclude the conduct of inertial confinement fusion experiments using direct drive. This involves symmetrical illumination of an ICF capsule, where each beam fully subtends the capsule. The re-directing of 24 of the 48 NIF beamlines (2x2 beamlet group each) from 30 and 50[degree] cone angles to 75[degree] cone angles near the chamber'equator' is required. This would be done by adjusting intermediate transport mirrors so that the beams intercept different final mirrors in the Target Bay and be directed into final optics assemblies attached to chamber ports positioned at the new port locations. Space for converting from one irradiation scheme to another is a problem; also NIF user needs cannot be compromised by direct drive needs. Target for direct drive, absent a hohlraum, emits much fewer cold x rays than for indirect drive. Further, the irradiation scheme may not result in the absorption of all the 3[omega] light and this may create a hazard to the NIF chamber first wall. This paper describes possible design features of the NIF Target Area to allow conversion to direct drive and discusses some differences in post-shot conditions created compared to indirect drive.
