Physics and Astronomy Colloquium Series
Fall 2010

Date

Talk

Thursday
9 September

No Colloquium

Thursday
16 September

Summer Student Poster Day

The department hallways will be decorated by posters by Union College physics majors who participated in summer research this year. The authors will stand by their posters to discuss their work and answer our questions while we all enjoy lunch during our first official colloquium of the new academic year.

Thursday
23 September

Carbonaceous Contamination on Extreme Ultraviolet Lithography Mirrors Due to Different Wavelengths of Light

Petros Thomas
SUNY Albany

Extreme Ultraviolet Lithography (EUVL) is one the leading candidates as the next generation of lithographic technology for the semiconductor industry. One of the challenges of EUVL is the carbonaceous contamination of the multilayer EUV mirrors in the tool which reduces the reflectivity of the mirrors in the desired wavelength range. Carbonaceous contamination on optical surfaces due to light in hydrocarbon environment is a major problem in different applications such as synchrotron beam lines, astronomy telescopes, and recently in EUV lithography. Although the problem has been around for a long time, the basic mechanism of the contamination is still not fully understood. The contamination is localized to the region of the surface exposed to light in the presence of hydrocarbons. The hydrocarbons dissociate and leave carbonaceous film in the exposed region of the surface. Whether the dissociation of the hydrocarbons is caused by the incoming photons of the light or secondary electrons from the surface is not well known.

Using a Xe-plasma source which emits not only the desired wavelength near 13.5 nm (EUV light) but a wide range of out-of-band (OOB) wavelengths extending as far as the visible region, we studied the carbonaceous contamination rates of different wavelength regions. We have measured the wavelength dependence of carbon contamination on a Ru-capped mirror. These results are compared to contamination rates on TiO₂ and ZrO₂ capping layers.

Thursday
30 September

Astrophysical Alchemy: Creating the Heaviest Elements Within the Galaxy's Biggest Explosions

Rebecca Surman
Union College

While the origins of the light (hydrogen, helium) and intermediate mass (carbon through iron) elements found in our solar system are well understood, we still don't know where roughly half of the elements heavier than iron were made. From the solar system abundance pattern of these nuclei, we can tell they were synthesized in conditions of high temperature and free neutron density. However, where these extreme conditions are found astrophysically is still uncertain. Here we will discuss aspects of heavy element synthesis in two potential astrophysical sites: the neutrino-driven wind of core-collapse supernovae and hot outflows from compact object mergers.

Thursday
7 October

The Physics of Baseball

Charles Freeman
SUNY Geneseo

Baseball is a particularly interesting game for a physicist to study. What makes a curve ball curve? How much farther does the ball really travel at Coors Field in Denver than at Citi Field in New York? Why do left handed pitchers have more success against left handed batters (and right handed pitchers have more success against right handed batters)? What is the difference between a two-seam and a four-seam fastball? How do you throw a split-fingered fastball, anyway? An ex-pitcher and current physicist sheds some light on these questions and discusses some other interesting physics at work in our national pastime. Feel free to bring your glove -- you just might catch a souvenir.

Thursday
14 October

Neutrino Physics and The Dayabay Experiment

John Cummings
Siena College

There has been a resurgence in interest in neutrino physics in the last 10 years. The observations of the Super-Kamiokande Experiment in 1998 indicated the ``oscillation'' of one flavor neutrino into another. Several experiments, now running or soon to begin, are attempting to map out the details of the neutrino mixing responsible for this oscillation phenomena. I will present a (brief) history of our understanding of the neutrino, and describe the phenomena of neutrino oscillations and what we can learn from them. Finally, I'll describe the Dayabay experiment and it's goals.

Thursday
21 October

Principles of Physics for Nuclear Power

William Ostendorff
Nuclear Regulatory Committee, Commissioner

Thursday
28 October NOTE: In Olin Auditorium

MRI in Clinical Neurology: Where Physics, Biology, and Medicine Line Up

Richard Simmons, MD (Union College Class of '99)
Schenectady Neurological Consultants

A discussion of the basics of magnetic resonance imaging (MRI), the rationale behind its use in the field of neurology, and case studies showing why MRI is so valuable in everyday neurological practice.

Thursday
4 November

available

Tuesday
9 November

The Origin of the Universe and the Arrow of Time

Sean Carroll
Caltech

One of the most obvious facts about the universe is that the past is different from the future. We can remember yesterday, but not tomorrow; we can turn an egg into an omelet, but can't turn an omelet into an egg. That's the arrow of time, which is consistent throughout the observable universe. The arrow can be explained by assuming that the very early universe was extremely orderly, and disorder has been increasing ever since. But why did the universe start out so orderly? I will talk about the nature of time, the origin of entropy, and how what happened before the Big Bang may be responsible for the arrow of time we observe today.

Schedule for Winter Term 2011