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Hitting the Ground Running: Computational physics education to prepare students for computational physics research
Authors:
Amy Lisa Graves,
Adam D. Light
Abstract:
Momentum exists in the physics community for integrating computation into the undergraduate curriculum. One of many benefits would be preparation for computational research. Our investigation poses the question of which computational skills might be best learned in the curriculum (prior to research) versus during research. Based on a survey of computational physicists, we present evidence that man…
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Momentum exists in the physics community for integrating computation into the undergraduate curriculum. One of many benefits would be preparation for computational research. Our investigation poses the question of which computational skills might be best learned in the curriculum (prior to research) versus during research. Based on a survey of computational physicists, we present evidence that many relevant skills are developed naturally in a research context while others stand out as best learned in advance.
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Submitted 8 April, 2020;
originally announced April 2020.
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Temperature and lifetime measurements in the SSX wind tunnel
Authors:
M. Kaur,
K. D. Gelber,
A. D. Light,
M. R. Brown
Abstract:
We describe electron temperature measurements in the SSX MHD wind tunnel using two different methods. First, we estimate $T_e$ along a chord by measuring the ratio of the $C_{III}~97.7~nm$ to $C_{IV}~155~nm$ line intensities using a vacuum ultraviolet monochrometer. Second, we record a biasing scan to a double Langmuir probe to obtain a local measurement of $T_e$. The aim of these studies is to in…
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We describe electron temperature measurements in the SSX MHD wind tunnel using two different methods. First, we estimate $T_e$ along a chord by measuring the ratio of the $C_{III}~97.7~nm$ to $C_{IV}~155~nm$ line intensities using a vacuum ultraviolet monochrometer. Second, we record a biasing scan to a double Langmuir probe to obtain a local measurement of $T_e$. The aim of these studies is to increase the Taylor state lifetime, primarily by increasing the electron temperature. Also, a model is proposed to predict magnetic lifetime of relaxed states and is found of predict the lifetime satisfactorily. Furthermore, we find that proton cooling can be explained by equilibration with the electrons.
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Submitted 10 September, 2018;
originally announced September 2018.
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Magnetothermodynamics: Measurements of the thermodynamic properties in a relaxed magnetohydrodynamic plasma
Authors:
M. Kaur,
L. J. Barbano,
E. M. Suen-Lewis,
J. E. Shrock,
A. D. Light,
D. A. Schaffner,
M. B. Brown,
S. Woodruff,
T. Meyer
Abstract:
We have explored the thermodynamics of compressed magnetized plasmas in laboratory experiments and we call these studies "magnetothermodynamics". The experiments are carried out in the Swarthmore Spheromak eXperiment device. In this device, a magnetized plasma source is located at one end and at the other end, a closed conducting can is installed. We generate parcels of magnetized plasma and obser…
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We have explored the thermodynamics of compressed magnetized plasmas in laboratory experiments and we call these studies "magnetothermodynamics". The experiments are carried out in the Swarthmore Spheromak eXperiment device. In this device, a magnetized plasma source is located at one end and at the other end, a closed conducting can is installed. We generate parcels of magnetized plasma and observe their compression against the end wall of the conducting cylinder. The plasma parameters such as plasma density, temperature, and magnetic field are measured during compression using HeNe laser interferometry, ion Doppler spectroscopy and a linear $\dot{B}$ probe array, respectively. To identify the instances of ion heating during compression, a PV diagram is constructed using measured density, temperature, and a proxy for the volume of the magnetized plasma. Different equations of state are analyzed to evaluate the adiabatic nature of the compressed plasma. A 3D resistive magnetohydrodynamic code (NIMROD) is employed to simulate the twisted Taylor states and show stagnation against the end wall of the closed conducting can. The simulation results are consistent to what we observe in our experiments.
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Submitted 31 January, 2018;
originally announced February 2018.
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Magnetothermodynamics: Measuring equations of state in a relaxed magnetohydrodynamic plasma
Authors:
M. Kaur,
L. J. Barbano,
E. M. Suen-Lewis,
J. E. Shrock,
A. D. Light,
D. A. Schaffner,
M. R. Brown
Abstract:
We report the first measurements of equations of state of a fully relaxed magnetohydrodynamic (MHD) laboratory plasma. Parcels of magnetized plasma, called Taylor states, are formed in a coaxial magnetized plasma gun, and are allowed to relax and drift into a closed flux conserving volume. Density, ion temperature, and magnetic field are measured as a function of time as the Taylor states compress…
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We report the first measurements of equations of state of a fully relaxed magnetohydrodynamic (MHD) laboratory plasma. Parcels of magnetized plasma, called Taylor states, are formed in a coaxial magnetized plasma gun, and are allowed to relax and drift into a closed flux conserving volume. Density, ion temperature, and magnetic field are measured as a function of time as the Taylor states compress and heat. The theoretically predicted MHD and double adiabatic equations of state are compared to experimental measurements. We find that the MHD equation of state is inconsistent with our data.
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Submitted 3 January, 2018; v1 submitted 18 August, 2017;
originally announced August 2017.
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Spatial Modulation Microscopy for Real-Time Imaging of Plasmonic Nanoparticles and Cells
Authors:
N. Fairbairn,
R. A. Light,
R. Carter,
R. Fernandes,
A. G. Kanaras,
T. J. Elliott,
M. G. Somekh,
M. C. Pitter,
O. L. Muskens
Abstract:
Spatial modulation microscopy is a technique originally developed for quantitative spectroscopy of individual nano-objects. Here, a parallel implementation of the spatial modulation microscopy technique is demonstrated based on a line detector capable of demodulation at kHz frequencies. The capabilities of the imaging system are shown using an array of plasmonic nanoantennas and dendritic cells in…
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Spatial modulation microscopy is a technique originally developed for quantitative spectroscopy of individual nano-objects. Here, a parallel implementation of the spatial modulation microscopy technique is demonstrated based on a line detector capable of demodulation at kHz frequencies. The capabilities of the imaging system are shown using an array of plasmonic nanoantennas and dendritic cells incubated with gold nanoparticles.
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Submitted 27 March, 2012;
originally announced March 2012.
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Current driven rotating kink mode in a plasma column with a non-line-tied free end
Authors:
I. Furno,
T. P. Intrator,
S. Abbate,
T. Madziwa-Nussinov,
A. Light,
L. Dorf,
G. Lapenta,
D. D. Ryutov
Abstract:
First experimental measurements are presented for the kink instability in a linear plasma column which is insulated from an axial boundary by finite sheath resistivity. Instability threshold below the classical Kruskal-Shafranov threshold, axially asymmetric mode structure and rotation are observed. These are accurately reproduced by a recent kink theory, which includes axial plasma flow and one…
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First experimental measurements are presented for the kink instability in a linear plasma column which is insulated from an axial boundary by finite sheath resistivity. Instability threshold below the classical Kruskal-Shafranov threshold, axially asymmetric mode structure and rotation are observed. These are accurately reproduced by a recent kink theory, which includes axial plasma flow and one end of the plasma column that is free to move due to a non-line-tied boundary condition.
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Submitted 26 August, 2006;
originally announced August 2006.