A5041602354- Ionosphere and magnetosphere dynamics
- Solar and Space Plasma Dynamics
- Plasma Diagnostics and Applications
- Earthquake Detection and Analysis
- Astro and Planetary Science
- Dark Matter and Cosmic Phenomena
- Laser-induced spectroscopy and plasma
- Planetary Science and Exploration
- Radiation Therapy and Dosimetry
- Astrophysics and Cosmic Phenomena
- Geophysics and Gravity Measurements
- Lightning and Electromagnetic Phenomena
- Magnetic confinement fusion research
- Gamma-ray bursts and supernovae
- Geophysics and Sensor Technology
- Seismic Waves and Analysis
- Atmospheric Ozone and Climate
- Geomagnetism and Paleomagnetism Studies
- Radioactivity and Radon Measurements
- Quantum Electrodynamics and Casimir Effect
- 3D Modeling in Geospatial Applications
- Tactile and Sensory Interactions
- Oil Spill Detection and Mitigation
- Currency Recognition and Detection
- High-pressure geophysics and materials
Massachusetts Institute of Technology
2023-2025
Calvin University
2024
Science Applications International Corporation (United States)
1989-2011
System Science Applications (United States)
1983
Bellevue Hospital Center
1983
University of Minnesota
1982
Rice University
1967-1980
University of Arizona
1966
California Institute of Technology
1963
We present results over an 11-year Solar cycle of cosmic antiprotons based on <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mn>1.1</a:mn><a:mo>×</a:mo><a:msup><a:mn>10</a:mn><a:mn>6</a:mn></a:msup></a:math> events in the rigidity range from 1.00 to 41.9 GV. The <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:mover accent="true"><c:mi>p</c:mi><c:mo stretchy="false">¯</c:mo></c:mover></c:math> fluxes exhibit distinct properties. magnitude...
A rocket-borne experiment consisting of a vector magnetometer system and energetic charged particle detectors was launched from Fort Churchill, Canada, over stable IBC II auroral arc at 2000 LT on February 26, 1969. Vector magnetic field profiles flux are presented which indicate the existence geomagnetically aligned sheet currents associated with visible arc. In particular, evidence is shown that suggests precipitated electrons in range 2 to 18 kev carry significant fraction total upward...
Precision measurements by the Alpha Magnetic Spectrometer (AMS) on International Space Station of deuteron (<a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:mi>D</a:mi></a:mrow></a:math>) flux are presented. The based <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:mrow><c:mn>21</c:mn><c:mo>×</c:mo><c:msup><c:mrow><c:mn>10</c:mn></c:mrow><c:mrow><c:mn>6</c:mn></c:mrow></c:msup></c:mrow></c:math> <e:math...
We report the properties of precision time structures cosmic nuclei He, Li, Be, B, C, N, and O fluxes over an 11-year solar cycle from May 2011 to November 2022 in rigidity range 1.92 60.3 GV. The show similar but not identical variations with amplitudes decreasing increasing rigidity. In particular, below 3.64 GV B fluxes, 2.15 are significantly less affected by modulation than He flux. observe that these differences linearly correlated spectral indices fluxes. This shows, a...
We present the precision measurements of 11 years daily cosmic positron fluxes in rigidity range from 1.00 to 41.9 GV based on 3.4×10^{6} positrons collected with Alpha Magnetic Spectrometer (AMS) aboard International Space Station. The show distinctly different time variations electron at short and long timescales. A hysteresis between is observed a significance greater than 5σ rigidities below 8.5 GV. On contrary, proton similar variation. Remarkably, we found that are modulated more for 7...
A Terrier‐Malemute rocket was launched from Poker Flat, Alaska, on March 9, 1978, over a stable premidnight auroral arc. It carried instrumentation to measure electric and magnetic fields particle fluxes. The electron intensity in 13 fixed energy intervals 0.04 40 keV measured 180° of pitch angle every half spin at ∽2.5 rps. generally isotropic the upper hemisphere with total flux spectral hardness greater visible arc than elsewhere. Field alignment low‐energy electrons occurred edges arc,...
The ionization rate and omnidirectional flux of radiation in interplanetary space were measured by similar ion chambers GM tubes on Mariners 2 4 during September-December 1962, November 1964 to March 1965, respectively. energy threshold (determined 0.2 g/cm² wall material) was 10 Mev for protons. Average values 681 pairs/ sec cm³ STP air 2.89 particles/cm² September-October 984 4.29 December January 1965. Daily averages when the spacecraft near earth correlate with Ottawa neutron monitor a...
During each of the summers 1962 and 1963 six balloon flights were made at Thule, Greenland (geomagnetic latitude 88°N), in continuation a program to follow secular changes primary cosmic rays. Similar Thule have been during most years beginning 1951. The usually extended over period least two weeks be sure that transient effects will minimized. Following substantial increase from 1961 20 per cent high altitudes, much smaller 7.5 occurred between 1963. Three after last night 1962, data had...
A rocket-borne experiment package has been designed to obtain simultaneous in situ measurements of the pitch angle distributions and energy spectra primary auroral particles, flux neutral hydrogen at energies, electric currents flowing vicinity arc as determined from vector magnetic data, modulation precipitating electrons frequency range 0.5-10 MHz. The was launched by a Nike-Tomahawk rocket Poker Flat, Alaska, 0722 UT on Feb. 25, 1972, over bright band. This paper is intended serve an...
Intense auroral hiss was observed by a sounding rocket payload under circumstances that have allowed detailed comparison of the spectrum with predictions convective beam amplification production model. The launched from Poker Flat, Alaska at 0813 UT on March 9, 1978; it carried an electric field detector and electron detectors covering energy range 30 eV to 25 keV. A complete pitch angle scan made every 0.2 s. trajectory close magnetic meridian crossed diffuse aurora, dark region, quiet 40...
The planetary probe Mariner 2 covered a radial distance of about 0.25 AU on its journey to the orbit Venus. In understanding effect sun cosmic rays, it is considerable interest determine how intensity radiation varies with from sun. Data ionization chamber can be used calculate change. At time was in transit, no monitor similar spectral sensitivity operating space at earth's orbit. lieu such, we use high–latitude neutron monitors located Deep River, Canada (λm = 57.5, Quenby–Webber cutoff...
Auroral electron flux measurements obtained with rocket-borne detectors have been used to model ionospheric effects and resulting optical radiations. The predicted emission rate of N/sub 2//sup +/ first negative group (4278 A) is in excellent accord ground-based observations made from Fort Yukon Ester Dome, Alaska. This measurement provides a test the energy deposition computations ionization-excitation efficiency model. Predictions (O I)5577 A, however, do not agree, on basis height profile...
Observations of ∼10-Mev protons were made over the polar regions by an ionization chamber during two solar proton events on March 24, 1966, which separated ∼3.5 hours. Short-term fluctuations in observed with factor 2 changes occurring ∼30 sec or ∼220 km. A nearly identical at 10–16 RE sunward no short-term fluctuations, and these differences are interpreted as spatial effects due to field structure poles. The occur mainly when density outside magnetosphere is increasing rapidly (by a per...
Pogo ion chamber measurement of ionization by penetratingg radiation, discussing spike intensity
We have observed strong VHF plasma waves with amplitudes in excess of 0.1 mV/m (Hz)1/2 associated 50 mA electron beam injections the ionosphere. These observations were made up to 44 MHz, which is approximately 20 times ambient frequency. Data from three swept‐frequency receivers carried on two daughter payloads been analyzed determine emission spectra for various energies and currents. results obtained rocket‐bome experiment SCEX 3 (Several Compatible EXperiments using a rocket‐borne...
Abstract topics such as recursion are challenging for many computer science students to understand. In this experience report, we explore function sonification-the addition of sound a communicate information about the function's behavior in real-time it runs-as pedagogical approach improving students' understanding recursion. We present several example iterative and recursive sonifications, plus spectrograms that illustrate their different sonic behaviors. also experimental evidence using...