Students interested in applying for a CASPER Fellowship should begin the application process by reading the descriptions of the active research areas within CASPER which are listed below.
A brief description of each research area along with selected papers and related links are supplied to provide applicants with relevant background material. A more comprehensive description with a list of selected CASPER papers and background reading material is included as a single pdf document below.
CASPER - HIDPL Summaries
Spacecraft in near-earth orbit and on deeper space missions are subject to damage from impacts with interplanetary dust and orbital debris. Low impact studies are designed to characterize the dust encountered in space and test materials for damage. Several experiments using two single-stage gas guns are underway, including:
- Corroboration of the sensitivity map for the stainless steel plate with piezoelectric lead zirconate titanate (PZT) crystals attached. The voltage and resonant frequency of the output from the sensor must be measured. A full understanding of the sensitivity map requires understanding not only the electrical response from the PZTs but also the acoustics of the plate, which must be measured as well.
- Completion of experiments on damage assessment of aluminum and stainless steel plates, using different projectile materials and sizes.
- Analysis of laser fan data, which measures the projectile's velocity in flight, to determine particle dimensions by the shape and amplitude of the signal.
Dust Crystals in an RF Reference Cell - Truell Hyde, Lorin Matthews, Jie Kong, Ke Qiao, Bernie Smith, Jorge Carmona, Mike Cook, Jimmy Schmoke
Dust particles immersed within a plasma environment acquire an electric charge. If the ratio of the inter-particle potential energy to the average kinetic energy is high enough the particles can form a "liquid" structure with short-range ordering, a crystalline structure with longer range ordering or a mixture of the two. A variety of experiments within complex plasmas investigating nano- and meso-scale physics will be on-going during the coming summer. Additionally, the S100 nano-manipulator brought on-line in June 2005, provides unparalleled perturbative capabilities for the lab. Complete lab diagnostics and theoretical simulation capabilities as well as full-time technical support providing machining capability and electronics R&D are also available to Fellows working within the HIDPL. A list of current projects available along with background reading material, is appended to this document.
CASPER – Experimental Astronomy Summaries
Experimental Astronomy - Dr. Dwight Russell and Mr. Dick Campbell
Using the CTAS(Central Texas Astronomical Society) telescope at the Clifton site, in collaboration with the UT astronomy department, we will study luminosity curves for white dwarf stars. The data will be taken and used to study periodic variations in the intensities of these stars. The expected periodicity is in the range of 1s to 1000s. This time scale allows for usable data to be taken in the relatively short period of time of one night to a few nights. The CTAS telescope is a state of the art computer controlled facility. The collaboration with UT-Austin will put this research into a larger context of white dwarf physics helping to guide this work toward publishable results. As part of this project, the student(s) will be involved in:
- star selection
- operation of the CTAS telescope via the internet interface
- the recording and analysis of the data. Raw Data will be in the form of CCD images that will need to be converted to light curves.
CASPER – ASSTG Summaries
Numerical Simulation of Plasma Crystals - Truell Hyde, Lorin Matthews, Ke Qiao, Jie Kong
Dust particles immersed within a plasma environment, such as those found in nanomanufacturing or in protostellar clouds, planetary rings or cometary environments, acquire an electric charge. If the ratio of the inter-particle potential energy to the average kinetic energy is high enough the particles will form either a "liquid" structure with short-range ordering or a crystalline structure with long range ordering. Properties of these dust crystals have been studied within CASPER both numerically and experimentally. The following numerical simulations utilize the Box_Tree code.
- Structure and phase transitions in 2D and 3D plasma crystals.
- Wave properties of a bilayer system (particle populations with different sizes).
- Simulation of wake force caused by ion drag and study of its effect.
- Simulation of the thermophoretic force and study of its effect.
Kuiper Belt Studies - Truell Hyde, Ray Nazzario
Recent observations show that binary Kuiper Belt objects exist contrary to most theoretical expectations. (These are the same objects that recently resulted in the 'demotion' of Pluto.) Although their creation presents problems in current models, the inclusion of a third body (ex. one of the outer planets or a forming protoplanet) often provides several of the necessary conditions for their formation. The presence of such a perturbing body can also provide clearing of the primordial Kuiper Belt while at the same time producing quasi-stable, longer-lived binary Kuiper belt objects. Numerical investigations involving a fifth order Runge-Kutta algorithm are employed to examine the situation described. Up to thousands of Kuiper belt sized objects are simulated to look for the formation of binaries (along with structure of the resulting belt) in both solar systems and protoplanetary situations. The interparticle gravitational interactions can create one of several effects; scattering into the Oort cloud, collisions with nearby growing protoplanets, formation of binary pairs, or creation of a single Kuiper belt object. Additionally, the initial location of the progenitors of the Kuiper belt objects may also have a significant effect on binary formation with objects near resonances tending not to form binary objects. A list of current projects available within the CASPER theory group, along with background reading material, is appended to this document.
Numerical Simulation of Preplanetary Dust Aggregation - Truell Hyde, Lorin Matthews
Recent data from the Hubble telescope show that planetary formation from the cloud of gas and dust orbiting a new protostar is a much more efficient process than first believed and may occur on a time scale of less than 10 million years. Initially uncharged grains in space and laboratory plasma environments become charged due to currents driven by potential differences in the dusty plasma. Certain macroscopic effects such as coagulation of smaller grains into larger fluffy aggregates are then affected by the grain charge. The charge distribution on the aggregate structure itself appears to play a role in determining the coagulation rate for the dust population. As particles collide, a numerical code can be used to determine the effect of the dipole and higher multipole charge distributions on the openness of the resultant fractal aggregate and the coagulation rates of the particles. A list of current projects available within the CASPER theory group, along with background reading material, is appended to this document.
Gravitoelectrodynamics in Saturn's Rings - Truell Hyde, Lorin Matthews
Saturn's magnetic field exerts a significant perturbative force on charged micron- and submicron-sized grains in its ring system. This force has been shown to cause the formation of "spokes" in Saturn's B ring and may possibly plays a large role in the formation of the evolving clumps, kinks, braids and waves observed in Saturn's F Ring. These effects can be modeled numerically using the Box_Tree code and can be used to predict or explain new features that currently being seen by the Cassini probe in orbit around Saturn. A list of current projects available within the CASPER theory group, along with background reading material, is appended to this document.
CASPER - EUCOS Summary
Theoretical Early Universe Cosmology and Superstrings - Gerald Cleaver
Over the last two decades, the theorized number of (meta)-stable string vacua (models) has jumped from only a few trillion to anywhere from 10100 to 101000. The collection of these string models has become known as the string landscape. No longer do string phenomenologists concentrate on examining the phenomenology and features of individual models, but on the common phenomenology of models within local neighborhoods on the string landscape. Thus, gradually different pieces of the landscape will become understood and eventually the pieces may fit together. Here at Baylor, properties of a class of models known as free fermionic heterotic models are under study, with primary attention given to special collection of them known as NAHE-based (names after the originators of this type of model-Nanopoulos, Antoniadis, Hagelin, and Ellis) free fermionic heterotic string models. One REU student will have the opportunity to do research on this collection of string models with Ph.D. students in Dr. Gerald Cleaver's Early Universe Cosmology and Strings (EUCOS) group. The REU student and graduate students will be analyzing patterns in the phenomenological properties of heterotic string models that will be generated by a computer program during spring 2008. They will be studying models with SU(5), SU(4) x SU(2) x SU(2), or SU(3) x SU(2) x SU(1) observable gauge groups.
CASPER - Joint GCAP/EUCOS Summary
Gerald Cleaver, Anzhong Wang
Discovery in 1998 that the expansion of the universe is accelerating (and has been for the last 6 to 7 billion years), and continued verification of this over the following decade, jarred physicists' and astrophysicists' understanding of the universe. Determining the cause of the acceleration, whether it is a cosmological constant or slowing varying dark energy, is a primary quest of theoretical physics. Pursuing this quest at Baylor is Dr. Anzhong Wang and his Gravity, Cosmology, and Astroparticle physics (GCAP) group and Dr. Gerald Cleaver and his Early Universe Cosmology and Strings (EUCOS) group. Together, these groups are exploring explanations for the current acceleration of the universe from the perspective of string/M-Theory cosmology and string/M-theory inspired Brane World models. REU students have the opportunity to work with the combined research teams of Drs. Gerald Cleaver and Anzhong Wang, and their graduate students as they pursue the origin of the acceleration of the universe.