Research Update:
Kresin's Cluster Beam Apparatus is Alive

Left to right: George Tikhonov, Vitaly Kasperovich, and Dr. Vitaly Kresin with cluster beam apparatus.

In January '97, Professor Vitaly Kresin's experimental cluster beam apparatus finally came to life after two years of assembling and upgrading. He and his new graduate students, Vitaly Kasperovich and George Tikhonov, were able to obtain the first real signal. Kresin's apparatus was born in the lab at UC Berkeley where he did his graduate work. Even then it was one of the bigger and more flexible cluster machines in the field; since then Dr. Kresin has further modernized and improved it.

Using this apparatus, Professor Kresin carries out experimental and theoretical research on microclusters -- agglomerates of a finite number of atoms (from a few to thousands) which are bigger than a molecule but smaller than a piece of bulk matter. In the experimental apparatus, a beam of cluster particles is generated and flies through a series of vacuum chambers. While in flight, the clusters are subjected to various probes. Finally they pass through a mass spectrometer, which can be set to focus on a particular particle mass or to scan through a range of masses. In this way the intrinsic properties of a free cluster, the size of which (i.e., the number of atoms in it) is known precisely, can be studied.

Work in this field allows for considerable interaction with solid-state, atomic, chemical, and even nuclear physics, and has practical implications for surface science, nanoelectronics, catalysis, environmental studies, as well as many other fields.

At present, together with the graduate students and with the help from two undergraduates, Kyler Kuehn and Frank Lu, Kresin's group is pushing on to whip the cluster beam apparatus into shape and to analyze new data. This current program includes experiments on the scattering of atoms, molecules, and electrons off clusters, as well as measurements of the cluster response to external electric fields.