Photonuclear physics - Laser light splits atom

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62874/1/404239a0.pd

Guiding of relativistic electron beams in dense matter by laser-driven magnetostatic fields

Intense lasers interacting with dense targets accelerate relativistic electron beams, whichtransport part of the laser energy into the target depth. However, the overall laser-to-targetenergy coupling efficiency is impaired by the large divergence of the electron beam, intrinsicto the laser-plasma interaction. Here we demonstrate that an efficient guiding ofMeV electrons with about 30MA current in solid matter is obtained by imposing a laserdrivenlongitudinal magnetostatic field of 600 T. In the magnetized conditions the transportedenergy density and the peak background electron temperature at the 60-μm-thicktarget's rear surface rise by about a factor of five, as unfolded from benchmarked simulations.Such an improvement of energy-density flux through dense matter paves the ground foradvances in laser-driven intense sources of energetic particles and radiation, driving matter toextreme temperatures, reaching states relevant for planetary or stellar science as yet inaccessibleat the laboratory scale and achieving high-gain laser-driven thermonuclear fusion

Nuclear physics merely using a light source

The interaction of ultra-intense focused laser beams with solid targets is a new field of research resulting in the production of exotic plasma conditions similar to the conditions which exist in the interior of some stellar objects. The lasers generate very high energy electrons and ions which can subsequently produce γ-rays, positrons, neutrons and pions. The results obtained from these studies have major implications to fundamental plasma physics and high energy accelerator physics as well as important technological potential for the production of compact sources of neutrons, positrons and isotopes

Applications for nuclear phenomena generated by ultra-intense lasers

The amplification of laser light to generate powers large enough to affect the nucleus has been the desire of scientists since the invention of the laser 40 years ago. Many lasers, including tabletop varieties, now have pulse powers greater than the electrical power generated by all the world's power plants combined. When this power is focused to dimensions of a few microns, laser-driven nuclear phenomena can occur. Here we review the developments in this research field and describe the potential of laserproduced proton, neutron, and heavy ion beams, together with isotope and isomer production

Ionisation and fragmentation dynamics of laser desorbed polycyclic aromatic hydrocarbons using femtosecond and nanosecond post-ionisation

Nanosecond laser desorption/femtosecond laser mass spectrometry (LD/FLMS) incorporating a reflectron time-of-flight mass spectrometer has been used to study the ionisation/fragmentation of polycyclic aromatic hydrocarbons (PAHs) in intense laser fields (7.0×1014 to 9.3×1015 W cm−2). Pulses of 80 fs, 800 nm have been used to post-ionise the PAHs anthracene, tetracene and pentacene. For each molecule strong singly and doubly charged parent ions are observed accompanied by fragmentation. In addition, strong triply charged parent ions (M3+) are observed for anthracene and weaker M3+ signals for tetracene and pentacene are also observed. Nanosecond post-ionisation (266 nm, 16 ns) spectra of the molecules have been recorded and are included for comparison with the femtosecond data. Similarities in the observed fragmentation pattern of low-mass fragments of the nanosecond and low intensity femtosecond spectra are highlighted. In addition, as the laser intensity increases, it is observed that fragmentation pathways preferentially switch from CmH3+ ion yield to Cm+ production for m=2-5 at a critical intensity which is molecule dependent