לוח שנה משולב

I will provide some background on fundamental high energy density
physics (HEDP) done on NIF, focussing particularly on plasma
astrophysics. Through specific examples, I will try to illustrate how
laboratory HEDP can serve as a powerful tool for reaching a better
understanding of the the physics of astronomical systems.

To date, about 500 extrasolar planets (exoplanets) have been discovered orbiting other stars. Of those some 100 are transiting (eclipsing) their host star, allowing a much more detailed investigation, including the measurement of their radius and mass, and the study of their atmospheres. Most of those exoplanets are gas giants the size of Jupiter. Kepler is an ambitious NASA Discovery mission whose primary goal is to measure the frequency of small, Earth-like planets, orbiting Sun-like stars in their Habitable Zone, where liquid water can exist on the planet's surface. I will
discuss the exciting new results recently obtained by Kepler, including the detection of about 1,200 transiting planet candidates and 170 multiple
transiting planet systems.

Nanoparticles used in biomedical applications must exhibit well-controlled surface properties to achieve optimum performance in complex biological or physiological fluids. Thus, there is a real need for development of rigorous and detailed surface analysis methods for the characterization of functionalized nanoparticles. Examples of new methods developed to quantitatively analyze funtionalized gold nanoparticles (AuNPs) and quantum dots (QDs) will be described in this talk.
The surface chemistries of C16 carboxylic acid terminated self assembled monolayers (COOH-SAMs) on 14nm AuNPs and flat Au surfaces were characterized with XPS, TEM, FTIR and ToF-SIMS. Simulated Electron Spectra for Surface Analysis (SESSA) was used to simulate the experimental XPS results as a function of take-off angle for COOH-SAMs on flat-Au surfaces. Quantities such as SAM density, thickness, surface roughness and instrumental parameters were tuned in SESSA to optimize agreement between simulated and experimental XPS compositions for SAMs on flat Au surfaces. Then the SESSA results were used to measure the thicknesses of the COOH-SAMs on the 14nm AuNPs.
The structure and chemistry of CdSe-based QDs were characterized with XPS, TEM and ToF-SIMS. XPS results showed the QDs had a CdSe core, a CdS intermediate shell and a ZnS outer shell. ToF-SIMS showed the QD surface was covered with a range of different hydrocarbon ligands including octadecylphosphonic acid, trioctylphophine oxide, and stearate. Encapsulation of the QDs with poly(maleic anhydride-alt-1-tetradecene) was also characterized using XPS and ToF-SIMS.