CONTACTS
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Projects and Mentors
The following mentors have agreed to host a student this year. Feel free to contact them
and discuss their projects or your own project ideas with them. You can also look at
other ISR-1,2 members
and contact them for potential mentoring during the summer school.
Mentor: Burward-Hoy, Jane
General Interests:Instrumentation, Device Physics, Space Physics
Project Topics:
- Energetic Particle Instrumentation for Space-Flight Applications
Work is related to space-flight instrumentation that produces space weather data products,
and in particular, energetic particle measurements at LEO, MEO, and GEO. Our team designs
and delivers the next generation energetic particle instruments based on our group's
heritage and expertise dating back to the early 1960's and the Vela Hotel program. Our
primary focus this year includes calibrating energetic particle instruments at beam lab
facilities that include Goddard Space Flight Center, LANL's Ion Beams Materials
Laboratory, Lawrence Berkeley National Laboratory, and Brookhaven National Laboratory. We
are also developing Monte Carlo simulation methods to determine instrument responses using
GEANT4 and/or MCNPX. Programming work includes post-processing data analysis codes in C++
and ROOT environments and analyzing, interpreting space weather data products.
Electronics work related to a Technology Development proposal would exploit a
time-of-flight technique for ion identification. A US person status is required due to
Export Controls.
Contact Mentor
Mentor: Chen, Yue
General Interests: Earth's radiation belts, generation of waves in the radiation
belt region, wave and particle interactions, Electron acceleration, Electron
precipitation, proton trapping and detrapping, empirical radiation belt models
Project Topics:
- Understanding the Impact of Solar Proton Events on the Earth’s Proton Radiation Belt
The Earth’s radiation belts trapped by the geomagnetic field present a hazardous
radioactive environment to space missions. Specifically, protons of up to 100s of MeV
energy dominate the inner belt (L<~2) that is usually stable except for during solar
eruptive times such as the solar proton events (SPEs). It is known that SPEs carry a
highly variable component of energetic protons that impinge on the Earth’s magnetosphere
and can sometimes form a new proton belt, but the exact mechanism of trapping and
detrapping SPE protons remains an intriguing and open question. From the practical
perspective, phenomena caused by the proton belt include total does effects and single
event effects that adversely affect spacecraft operation, as well as the biological effect
on human issues that is also a serious concern for manned missions. Therefore,
understanding how SPEs impact the proton belt is of great both theoretic and practical
importance. In this project, we will explore this question by looking into in-situ proton
measurements from multiple satellite missions. We will also use particle tracing codes to
study the trapping and detrapping conditions for newly injected protons. Both detailed and
statistical studies will be included.
Contact Mentor
Mentor: Cox, Larry
General Interests: ionospheric physics, data assimilation
Project Topics:
Contact Mentor
Mentor: Friedel, Reiner
General Interests: radiation belts, data analysis
Project Topics:
- Computing Radial Diffusion Coefficients using CRRES Electric and Magnetic Field Data
It is well known that radial diffusion is responsible for populating and
depleting the van Allen radiation belts with high energy charged
particles. Data from satellites such as CRRES suggests that radial
diffusion of these particles depends on radial distance (L), intensity
of magnetic activity (Kp), and possibly others. Previous work has been
done by Brautigam et al. (2005) to use the CRRES electric field data to
estimate the electric field power spectral density and compute the
electrostatic component of the radial diffusion coefficients for the
simplified Fokker-Planck equation in the case of first two adiabatic
invariants being conserved. Brautigam et al. assumed that these
coefficients depend only on L and Kp. However it appears that more
parameters may be necessary.
This project for LANL space weather summer school has the
following objectives.
1.Using the CRRES magnetometer data, we will estimate the magnetic field
power spectral density as a function of L, Kp, and local time. The PSD
will then be used to derive the electromagnetic component of the radial
diffusion coefficients.
2.Power spectrum analysis on the CRRES electric field data will be
conducted more in depth to determine dependence on other parameters
besides just L and Kp. The electrostatic components will be
recalculated with these new parameters. The two components added up
together will give us the radial diffusion coefficients.
3.All of the CRRES datasets used above with the highest resolution
available, will be merged, cleaned up, and made available to others in a
ready to use format for scientific research through outlets such as
CEDAweb archives and ViRBO. Tools such as autoplot at ViRBO allow a
quick and easy interaction with the data available.
Contact Mentor
Mentor: Godinez, Humberto
General Interests:data assimilation, ensemble Kalman Filter, collision probabilities, ensemble simulation, orbital dynamics
Project Topics:
- Collisional Probabilities in Space
Accurate estimation of collison probabilities for space objects depend
on various factors. Among the most important is an accurate description
of the probability density function of the orbit of each individual
object. In this project we will implement an ensemble simulation for the
orbit of each object, for a number of different space object. The main
objective is to efficiently simulate the probability density function of
the orbit of the space object in order to calculate collision
probabilities. The project will require both theoretical knowledge of
orbital dynamics and practical knowledge of ensemble simulation.
Contact Mentor
Mentor: Koller, Josef
General Interests: Radiation belt modeling, orbital drag, space debris, machine learning
Project Topics:
- Parameter Estimation in Radiation Belt Modeling
The space environment in the inner magnetosphere is highly dynamics and poses a number of
hazards to space systems. Los Alamos has developed an open source environment for
radiation belt modeling and data assimilation with the SpacePy library. A numer of
input parameters play an important role in radiation belt modeling. However, these
parameters are time-dependent and poorly determined. This project will
implement parameter estimation routines in the SpacePy library and estimate e.g. local
acceleration parameters, diffusion parameters, wave activity etc. The result will be a
time-series that can be correlated to solar wind drivers. The parameter estimation will
be done in conjunction with data assimilation using an ensemble Kalman Filter.
- Orbital drag data analysis
The density of the upper atmosphere (120km and above) is typically modeled with an
empirical density model which can be used to calculate drag forces on satellites.
However, these empirical density models have limitations. Los Alamos has recently
initiated a new project to develop a physics based model of the upper atmospheric
densities: IMPACT (Integrated Modeling of Perturbations in Atmospheres for Conjunction
Tracking). The goal of this project is to employ precision orbital data to fit atmospheric
densities to the satellite ephemeris. This will yield in thermospheric density data that
can be used for data assimilation into our physics based density model GITM from Michigan
University.
Contact Mentor
Mentor: MacDonald, Liz
General Interests: plasma mass spectrometer instruments and technology development,
wave-particle interactions and the effect of plasma on radiation belt dynamics, mapping
and coupling between the ionosphere and the inner magnetosphere, the impact of heavy ions
on geomagnetic storm processes, and space weather
Project Topics:
- Remote sensing of wave-particle interactions using LANL-GEO data
LANL particle data are available from geosynchronous orbit for over 70 satellite years of
data. Harnessing the power of this multi-point data to understand wave-particle dynamics
in the magnetosphere will be the focus of this project. Specifically, the student will
work with IDL code to examine the plasma particle distributions for certain plasma wave
instabilities, e.g. EMIC mode, whistler mode, and magnetosonic mode. A superposed epoch
analysis technique will be used to examine the dependencies of the distributions on
various forms of geomagnetic activity. These studies will be relevant for future missions,
especially for scientific topics of interest to NASA's upcoming Radiation Belt Storm
Probes. The research focus may shift before the summer or may be tailored more to the
student's interests; this may include more or less of instrumentation test and design,
website design, and/or PIC models of plasma plumes. Previous experience with IDL and
working independently in space physics is desired. Please contact me for more information.
Contact
Mentor
Mentor: Steinberg, John
General Interests: solar wind,
interplanetary electrons, interplanetary field,
solar wind origins, co-rotating interaction regions,
coronal mass ejections, space plasma instrumentation
Project Topics:
- Probing Structure in the Solar Wind using Electrons
Solar wind is variable in its bulk flow parameters of speed, density, and temperature, as
well as its ion composition. In addition, the entrained interplanetary magnetic field
exhibits smoothly varying features as well as discontinuities. Some large-scale features
are unambiguously related to a solar-coronal source: for example high-speed streams that
recur with the solar rotation, or coronal mass ejections that are observed to be
explosively blown out of the corona. In contrast, solar wind variations on medium times
scales, i.e. minutes to hours, are variably attributed to (1) frozen in fossil coronal
variations or (2) dynamic features that develop in the propagating solar wind. We wish to
probe the viability of these two different physical descriptions by comparing ACE
satellite measurements of suprathermal electrons (70 eV – 1.4 keV) with simultaneous
observations of solar wind ions and magnetic field. Will the electrons show
characteristic changes in association with magnetic discontinuities, ion composition
boundaries, or velocity shears for example? Or will electrons exhibit variations
uncorrelated to the ions and field? Through these comparisons we hope to shed new light
on the nature of solar wind plasma.
Contact
Mentor
Mentor: Terry, Russ
General Interests: radiation measurements, detectors
Project Topics:
- Characterization of a Silicon Carbide Detector
Silicon carbide (SiC) is a promising material for ionizing radiation measurements in harsh
environments, including high radiation environments and extreme temperatures. However,
compared to a more mature technology such as silicon, SiC crystal growth is prone to
significant material defects which limit the performance of the crystal as a radiation
sensor. Recent developments in thin film epitaxial growth of SiC crystals have yielded
detector quality crystal on the order of 10's to 100's of microns thick. Such devices
have been shown to be suitable for soft x-ray measurement, and custom sensors have been
developed through a collaboration with the University of South Carolina. We have acquired
several diodes and will test these at LANL through electronic characterization and
measurements with radioactive sources.
Contact
Mentor
Mentor: Yiqun, Yu
General Interests:Magnetosphere - Ionosphere Coupling, Radiation Belt Modeling
Project Topics:
- Responses in the MI-coupling System to Interplanetary Transient Impact
The transient changes in the solar wind and interplanetary magnetic field have significant
impact on the terrestrial Magnetosphere-Ionosphere system. A sudden increase in the solar
wind dynamic pressure results in a two-phase response in the terrestrial system, typically
characterized by the emergence of two successive pairs of convectional cells with opposite
polarities in the dayside high-latitude ionosphere and the bipolar variations of magnetic
field perturbations on the ground. While the ionospheric react has been extensively
explored and characterized, the two-phase response within the magnetosphere lacks clear
identification. The work will examine the two-phase response in the magnetospheric
magnetic and electric fields through in-situ measurements.
Contact Mentor
Mentor: Zaharia, Sorin
General Interests:Plasma physics, inner magnetospheric physics, ring current
Project Topics:
- Using Low- and High-altitude Measurements to Elucidate the Magnetic Connection Between
Magnetosphere and Ionosphere
Understanding magnetosphere-ionosphere interaction requires the ability to link
magnetospheric and ionospheric/ground signatures through the magnetic field. This project
seeks to improve the knowledge of this field by using low-altitude (FAST, DMSP) and high-altitude
(Geotail, THEMIS) data to constrain a first principle three-dimensional magnetospheric
plasma force balance model. Previous research using this model has employed equatorial
plasma pressure to calculate the magnetic field in force balance with it. In this project
we include additional observational constraints from low-altitude data that will greatly
improve the magnetic field solutions. Specifically, particle measurements will be used to
identify the “isotropy boundary,” a key concept providing constraints on both the field
curvature in the plasma sheet and the magnetic mapping. Low-altitude magnetic field
measurements from DMSP will allow the calculation of field-aligned current boundaries at
the ionosphere and thus provide an additional observational constraint for the model.
Contact Mentor
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