My name is Andrew Collette; I am an experimental physicist and software developer, currently working as a research scientist at the Laboratory for Atmospheric and Space Physics (LASP) attached to the University of Colorado Boulder.
In addition to my research work at LASP, I founded and manage the HDF5 for Python project, which allows access to terabyte-scale scientific datasets from the Python programming language.
I wrote an O’Reilly book on dealing with large-scale datasets from Python, which was published in November 2013.
I am a research scientist at the Institute for Modeling Plasma, Atmospheres and Cosmic Dust (IMPACT) at CU Boulder/LASP. IMPACT is a NASA-funded team which aims to better understand the environment of the Moon and other airless bodies through a combination of experiment, theory, and computer simulation. Our parent organization is NASA’s Solar System Exploration Research Virtual Institute.
As an experimental physicist, most of my work takes place on the flagship machine at IMPACT, a hypervelocity dust accelerator capable of firing micron-sized dust grains at speeds up to 100 km/s (224,000 miles per hour). This includes the first-ever experimental observation of neutral gas generation by dust impact, a capability unique to this facility, as well as direct time-resolved observation of the temperature of the micron-sized debris cloud.
When I arrived at IMPACT (formerly named CCLDAS) in July of 2010, the accelerator facility consisted of a large empty room. Over the next year and a half, I worked with faculty, researcher colleagues and students to build the accelerator into a world-class research device.
As a part of that work, I took the lead in designing and implementing the CCLDAS/IMPACT database system, a MySQL-Python-Labview-IDL system which tracks every dust particle fired by the accelerator. Data from over 500,000 dust “shots” are now managed by this system, including particle metadata as well as raw scientific waveform data. Scientists can easily search for and retrieve their data in a structured binary (HDF5) format; additionally, a web-facing component for data retrieval is currently under development to allow facility users to browse and retrieve data while at their home institutions.
The system was constructed over a period of approximately one year, using largely undergraduate and grad student labor under close supervision. The database and UI are quite easily extensible; research colleagues at IMPACT continue to integrate components including online beam profiling and an FPGA-based system for particle selection.
Other infrastructure tasks included designing and managing development of the IMPACT vacuum interlock and valve control system, and designing/commissioning our ultrahigh vacuum target chamber. This unusually large, ~ 1 cubic meter vacuum system provides the extremely low pressures necessary for my experiments (10^-10 torr, about 10^-13 of Earth’s normal atmospheric pressure).
Below: In early 2011, celebrating the very first dust particle to go through our accelerator. Left to right, grad student Anthony Shu, professional researcher Keith Drake, and me. A live webcam of the accelerator is also available.
UCLA Large Plasma Device
Before starting at CCLDAS/IMPACT in July of 2010, I worked as a graduate researcher at the UCLA Basic Plasma Science Facility, under Walter Gekelman. My research work was carried out on the Large Plasma Device (LaPD), a world-class basic plasma research device supporting a quiet 60cm x 16 meter strongly magnetized discharge plasma. I also founded the HDF5 for Python project while at UCLA.
My dissertation was on the behavior of a dense, expanding laser-generated plasma within the LaPD background plasma. Inside LaPD, a carbon cylinder was suspended within the plasma and hit with the pulse from a Nd:YAG laser. A dense blowoff plasma forms and propagates across the background field. The expanding plasma causes a “magnetic bubble” to form. Two-probe correlation measurements indicate the presence of large electrostatic structures on the plasma surface.
Below: A movie showing magnetic field vectors from a pair of counter-propagating magnetic bubbles. This isn’t a computer simulation; it’s real experimental data I acquired with the LaPD probe system.
A. Collette. Python and HDF5: Unlocking Scientific Data. O’Reilly, 2013 (in press).
A. Collette, Z. Sternovsky, M. Horanyi. Production of neutral gas by micrometeoroid impacts. Icarus, 2013 (in press). DOI: 10.1016/j.icarus.2013.09.009
A. Collette et al. Time-resolved temperature measurements in hypervelocity dust impact. Planetary and Space Sciences, 2013 (in press). DOI: 10.1016/j.pss.2013.02.007
A. Collette and S. Robertson. An ion analyzer for the lunar surface with E-parallel-B. Advances in Space Research, 50 (12), 1592-1599, 2012.
A. Shu, A. Collette, K. Drake et al. 3 MV hypervelocity dust accelerator at the Colorado Center for Lunar Dust and Atmospheric Studies. Rev. Sci. Instr. 83, 075108, 2012.
A. Collette and W. Gekelman. Structure of an Exploding Laser-Produced Plasma. Phys. Plasmas 18, 055705, 2011.
A. Collette and W. Gekelman. Structure of an Exploding Laser-Produced Plasma. Phys. Rev. Lett. 105, 195003 (2010)
W. Gekelman, E. Lawrence, A. Collette, et al. Magnetic field line reconnection in the current systems of flux ropes and Alfven waves. Phys. Scr. T142 014032 (2010)
A. Collette and W. Gekelman. Two-dimensional micron step probe drive for laboratory plasma measurement. Review of Scientic Instruments 79, 083505, 2008
W. Gekelman, S. Vincena, and A. Collette. Visualizing three-dimensional reconnection in a colliding laser plasma experiment. IEEE Trans. Plasma Sci. 36 (4) 2008
W. Gekelman, A. Collette, S. Vincena. Three Dimensional Current Systems Generated by Plasmas Colliding in a Background Magnetoplasma. Physics of Plasmas 14, 062109, 2007