Diagnostics for the laser fusion program: plasma physics on the scale of microns and picoseconds

Laser induced fusion is the forerunner of a class of inertial confinement schemes in which hydrogen isotopes are heated to thermonuclear conditions in a very short period. The process is characterized by such short time scales that fuel confinement is achieved through its' own finite mass and expansion velocity, approaching 1 ..mu..m/psec for ignition temperatures of order 10 keV (10/sup 8/ /sup 0/K). With current laser powers limited to several terrawatts one readily estimates, on the basis of energy conservation, target mass, and expansion velocity, that target size and laser pulse duration are on the order of 100 ..mu..m and 100 psec, respectively. Within these constraints, targets have been heated and confined to the point where thermonuclear conditions have been achieved. This paper describes a sampling of diagnostic techniques with requisite resolution (microns and picoseconds) to accurately describe the dynamics of a laser driven compression. As discussed in each case cited, these in turn provide insight to and quantitative measure of, the physical processes dominating the implosion. The success of the inertial confinement fusion program is strongly dependent on the continued development of such diagnostics and the understanding they provide

Ultra-fast image converter streak cameras for laser fusion diagnostics

The design and operation of a 10-ps resolution optical streak camera used to characterize laser pulses and other transient optical signals in fusion research is discussed. Performance characteristics are presented. The design, operation, and application of an x-ray streak camera used to study laser-produced plasmas in the x-ray spectral region of 1 to 10 keV with temporal and spatial resolutions of approximately 20 ps and approximately 10 $mu$m is also discussed. (auth

Cellular and molecular mechanisms involved in the neurotoxicity of opioid and psychostimulant drugs

Substance abuse and addiction are the most costly of all the neuropsychiatric disorders. In the last decades, much progress has been achieved in understanding the effects of the drugs of abuse in the brain. However, efficient treatments that prevent relapse have not been developed. Drug addiction is now considered a brain disease, because the abuse of drugs affects several brain functions. Neurological impairments observed in drug addicts may reflect drug-induced neuronal dysfunction and neurotoxicity. The drugs of abuse directly or indirectly affect neurotransmitter systems, particularly dopaminergic and glutamatergic neurons. This review explores the literature reporting cellular and molecular alterations reflecting the cytotoxicity induced by amphetamines, cocaine and opiates in neuronal systems. The neurotoxic effects of drugs of abuse are often associated with oxidative stress, mitochondrial dysfunction, apoptosis and inhibition of neurogenesis, among other mechanisms. Understanding the mechanisms that underlie brain dysfunction observed in drug-addicted individuals may contribute to improve the treatment of drug addiction, which may have social and economic consequences.http://www.sciencedirect.com/science/article/B6SYS-4S50K2J-1/1/7d11c902193bfa3f1f57030572f7034

Applications of short wavelength radiation : Soft X-ray microscopy and EUV lithography

Short wavelength radiation, in the 1-20 nm wavelength range is discussed, with particular emphasis on applications to soft x-ray (SXR) microscopy and extreme ultraviolet (EUV) radiation. In this paper we bring attention to the fact that these two applications require a wide variety of SXR/EUV sources, some with good spatial coherence, others largely incoherent ; some at fairly high average power (tens of watts), others at rather low (microwatts) power ; some at fixed wavelength, others tunable. These provide great opportunities for attendees of this workshop who represent the world's body of knowledge in this area. We give reference to recent papers to illustrate these points, and call attention to recurring publications where further opportunities and progress can be monitored

SHORT WAVELENGTH OPTICS FOR FUTURE FREE ELECTRON LASERS

Although much free-electron laser work is directed toward achieving sufficient single-pass gain to be useful for research purposes, the availability of mirrors of high reflectance for the vacuum ultraviolet and soft x-ray regime would make resonant cavities a possibility. In addition, as in ordinary synchrotron radiation work, mirrors are required for the construction of realistic experiments and for beam manipulation purposes such as folding and extraction. The Working Group discussed a number of approaches to reflecting optics for free electron lasers, which are summarized here, and described in some detail. 16 references, 2 figures