摘要:

The concept of laser fusion was devised very shortly after the invention of laser. In 1972, the Institute of Laser Engineering, Osaka University was established by the author in accordance with the Edward Teller’s special lecture on ‘‘New Internal Combustion Engine’’ for IQEC at Montreal which predicted the implosion fusion. In 1975 we invented the so called indirect drive fusion concept ‘‘Cannonball Target’’ which became later to be recognize as a same concept of ‘‘Hohlraum Target’’ from Livermore. As well known, ICF research in the US had been veiled for a long time due to the defense classification. While researchers from Japan, Germany and elsewhere have concentrated the efforts to investigate the inertial fusion energy which seems to be very interesting for a future civil energy. They were publishing their own works not only on the direct implosion scheme but also the indirect implosion experiment. These advanced results often frustrated the US researchers who were not allowed to talk about the details of their works. In 1988, international members of the ICF research society including the US scientists gathered together at ECLIM to discuss the necessity of freedom in the ICF research and concluded to make a statement ‘‘Madrid Manifest’’ which requested the declassification of the ICF research internationally. After 6 years of halt, the US DOE decided to declassify portions of the program as a part of secretary Hazel O’Leary’s openness initiative. The first revealed presentation from the US was done at Seville 1994, which however were well known already. Classification impeded the progress by restricting the flow of information and did not allow the ICF work to compete by the open scientific security. The implosion experiments by GEKKO XII Osaka demonstrated a high temperature compression of DT fuel up to 10 keV, neutron yield 1013and a high density compression of CDT hollow shell pellet to reach 1000 g/cm3respectively. These results gave us a strong confidence to reach the ignition and burn in near future. The international collaboration is now highly expected. ©1996 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.50538

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

The ICF Program has made exciting progress in the past year towards its goal of the achievement of fusion ignition and gain in the laboratory. A series of experiments on the Nova laser facility has resolved the major technical issues involved in the design of an ignition target. A baseline target has been designed that ignites (calculationally) with a nominal drive of 1.35 MJ (at 351 nm). In parallel, a detailed conceptual design for the National Ignition Facility (NIF‐a 1.8 MJ glass laser) has been completed and a successful laser beam line prototype has validated its architecture. As a result, the Department of Energy has requested funding for the preliminary design for the NIF from the U.S. Congress. With these developments, the attainment of the long‐sought goal is in sight. In addition, two new laser facilities (OMEGA Upgrade and Nike) have recently been completed, and ion‐beam fusion driver development is encouraging. Their availability expands the capability of the program to perform advanced ICF and plasma experiments. ©1996 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.50434

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

The progresses of laser fusion experiment by GEKKO XII and technology developments for inertial fusion energy in Japan are reviewed. New strategy of IFE addressing to reach the goal of IFE, power plant, is described. ©1996 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.50448

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

The major objectives of the CEA‐DAM laser program is to determine the various requirements to achieve thermonuclear fusion in laboratory. We report here recent results obtained at Centre d’Etudes de Limeil‐Valenton on high density X‐Ray implosions, radiative transfer processes, hydrodynamic instabilities and laser‐plasma interaction involved in cavity physics. Ignition and a moderate gain appears to be achievable with a laser energy of about 1.5−2 MJ delivered at &lgr;=0, 35 &mgr;m with a shaped pulse (duration∼16 ns). The construction of such a laser is realizable and a conceptual design is under preparation. ©1996 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.50401

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

The United States ICF Program has been pursuing an aggressive research program in preparation for an ignition demonstration on the National Ignition Facility. Los Alamos and Livermore laboratories have collaborated on resolving indirect drive target physics issues on the Nova laser at Livermore National Laboratory. This combined with detailed modeling of laser heated indirectly driven targets likely to achieve ignition, has provided the basis for planning for the NIF. A detailed understanding of target physics, laser performance, and target fabrication is required for developing robust ignition targets. We have developed large‐scale computational models to simulate complex physics which occurs in an indirectly driven target. For ignition, detailed understanding of hohlraum and implosion physics is required in order to control competing processes at the few percent level. From crucial experiments performed by Los Alamos and Livermore on the Nova laser, a comprehensive indirect drive database has been assembled. Time integrated and time dependent measurements of radiation drive and symmetry coupled with a detailed set of plasma instability measurements have confirmed our ability to predict hohlraum energetics. Implosion physics campaigns are focused on understanding detailed capsule hydrodynamics and instability growth. Target fabrication technology is also an active area of research at Los Alamos, Livermore, and General Atomics for NIF. NIF targets require developing technology in cryogenics and manufacturing in such areas as beryllium shell manufacture. Descriptions of our NIF target designs, experimental results, and fabrication technology supporting NIF target performance predictions will be given. ©1996 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.50477

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

Proposed by Prof. Ganchang Wang in 1964 and officially started in 1976 the ICF Program at CAEP includes research on every aspect of ICF science and technology: high power and energy laser technology, target fabrication, diagnostics, target physics, and potential applications. Two solid‐state lasers have been operated since the middle of the last decade. The most of research on target physics has been focused on indirect‐drive approach, covering laser‐plasma coupling, parametric instabilities and suprathermal electrons, x‐ray conversion and transport, plasma energetics, ablation, hydrodynamic instabilities. Neutron production experiments were conducted successfully on the Shenguang facility (2×800 J, 1 ns, and 1.053 &mgr;m) with radiation‐driven targets in 1990. In addition, equation of state experiments have been performed using both laser‐ and x‐ray‐driven targets for Fe, Cu, and glass. Furthermore, a much bigger laser facility is now being considered. ©1996 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.50487

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

Within the US ICF program the direct‐drive method has been chosen using the OMEGA facility based on the Neodymium glass laser. Requirements for the future experiments are reviewed and the design is outlined. ©1996 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.50500

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

Inertial Confinement Fusion (ICF) with heavy ion beams has a promising perspective for future energy generation. For the exploration of this concept Europe has a unique potential concerning the technologies involved. In particular, there is an excellent knowledge and experience in RF linear accelerators, storage rings and the handling of intense beams in European laboratories. During the last decade, key issues of ICF in the fields of accelerators, targets and systems have been studied in the framework of national programs. Intense heavy ion beams have been used in recent years to study the properties of matter under extreme conditions. ©1996 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.50533

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

High convergence, indirect drive implosion experiments have been done at the Nova Laser Facility. The targets were deuterium and deuterium/tritium filled, glass microballoons driven symmetrically by x rays produced in a surrounding uranium hohlraum. Implosions achieved convergence ratios of 24:1 with fuel densities of 19 g/cm3; this is equivalent to the range required for the hot spot of ignition scale capsules. The implosions used a shaped drive and were well characterized by a variety of laser and target measurements. The primary measurement was the fuel density using the secondary neutron technique (neutrons from the reaction2H(3H,n)4He in initially pure deuterium fuel). Laser measurements include power, energy and pointing. Simultaneous measurement of neutron yield, fusion reaction rate, and x‐ray images provide additional information about the implosion process. Computer models are in good agreement with measurement results. ©1996 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.50555

出版商:AIP    

年代:1996

数据来源: AIP

摘要:

Understanding drive symmetry in gas filled hohlraums is currently of interest because the baseline design of the indirect drive ignition target for the planned National Ignition Facility uses a gas filled hohlraum. We report on the results of a series of experiments performed at the Nova laser facility at Lawrence Livermore National Laboratory with the goal of understanding time dependent drive symmetry in gas filled hohlraums. Time dependent symmetry data from implosions in gas filled hohlraums will be discussed. The purpose of filling the hohlraum with gas is to tamp the motion of the high‐Zmaterial ablating from the hohlraum walls, reducing the motion of the laser deposition regions and resultant temporal variations in drive symmetry. We have obtained time integrated and time resolved x‐ray images of the implosion of plastic deuterium filled capsules, neutron yields, implosion times and spectroscopy of argon emission from the imploded core. Preliminary results show that the gas is effective in impeding the motion of the wall blowoff material, and that the resulting implosion is in qualitative agreement with modeling. These experiments are relevant to those currently being planned for the National Ignition Facility. ©1996 American Institute of Physics.

ISSN:0094-243X    

DOI:10.1063/1.50525

出版商:AIP    

年代:1996

数据来源: AIP