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Chilean students in the lab, January 2008

Daniel Rivas

Daniel is designing equipment in Prof. Cheng Chen's basement lab. He is constructing a tapered magnetic field that will allow a beam of atoms to be slowed down so that they can be trapped. The small picture shows his calculations. Next step is to wind the coils.

Jocelyn Dunstan

Jocelyn is working with postdoc Eric Brown and grad students John Royer and Xiang Cheng in Prof. Jaeger's lab. Her project concerns force chains, the network of strong forces that holds up a sandpile. She is looking at a model of such a layer of disks in two dimensions where the strong forces are visualized as bright streaks. The streaks are very nonuniform, even when the disks are nearly identical. Jocelyn is looking for a way to quantify this nonuniformity.

Cristian Erices

Cristian and neutrino detector

Cristian is working in Prof. Collar's group on the neutrino detector shown in the background. It is meant to detect a novel form of interaction: the neutrino scatters coherently from a massive nucleus in a large container of superheated fluid. The gentle recoil of the affected nucleus initiates a phase transition in the fluid. The detector when assembled and tested will be transferred to a site near a nuclear power reactor. Cristian has been helping put together and modify the detector. The apparatus will work unsupervised for many days at a time, and it needs to have control programs so that it can sense problems like loss of coolant or power failures and respond appropriately. Cristian is designing a control system that will automatically move a radioactive calibrating source into the sensitive volume of the detector and then withdraw the source.

Nicolas Rivas

The small picture shows Nico's apparatus, under the microscope and the plastic one can just make out the Langmuir trough, with its monolayer of lipid molecules. When this picture was taken, Nico had just made his first compression run and demonstrated the rise of surface pressure as the monolayer is compressed. Working with Luka Pocivavsek in Prof. Lee's lab, Nico will create wrinkles in the monolayer by placing small drops of water on the surface. Theory allows one to infer the elastic and bending stiffness of the monolayer by analyzing the number and length of these wrinkles.

Tibor Heumann

Tibor is showing his own Langmuir trough in the lab of Dr. Binhua Lin. The monolayers being studied here are made of 5-nanometer thick gold nanoparticles coated with alkane surfactants. When these are compressed in the langmuir trough linear wrinkles appear. Tibor is developing image analysis methods to find the wavelengths and heights of these wrinkles with software. This will enable them to study the speed at which small wrinkles grow to form large folds.