Mark Gilmore

Associate Professor

Electrical and Computer Engineering

and

Physics and Astronomy Departments

University of New Mexico

Research - The UNM Plasma and Fusion Science Group

 

 


Overview The HelCat Plasma Device Current Projects People Alumni  

Overview

The Plasma and Fusion Science Lab at the University of New Mexico was established in 2003.  The lab is headed by Prof. Mark Gilmore, and Research Profs. Alan Lynn, and Christopher Watts.  The lab is devoted to the study of basic physics, engineering applications, and space/astrophysical applications of plasmas.  We share lab space with the Pulsed Power, Beams, and Microwaves Laboratory headed by Prof. Edl Schamiloglu.

Our current research is focused on

The HelCat (Helicon-Cathode) Dual-Source Basic Plasma Physics Device

Our main research facility at UNM is the combined hot cathode and helicon laboratory plasma device, named HELCAT (Helicon-Cathode).  HELCAT has a 4 meter long, 50 cm diameter vacuum chamber.  Magnetic field coils produce an axial B-field of up to 2.2 kG.  Construction of this device was completed with funding from the U.S. Department of Energy Office of Science, and the UNM ECE Dept.

 

Helcat Diagnostics

  • Probes (B-dot, Langmuir, Double probe, Triple probe, milti-tip Langmuir, Mach)

  • Interferometers: 40 GHz and 94 GHz

  • Visible spectroscopy: survey and high resolution (4 meter McPherson)

  • Fast Camera (>= 1.2 ns/frame)

  • Laser Induced Fluorescence (in development)

 

HelCat Parameters

Device

Length: 4 m

Diameter: 50 cm

Magnetic Field: up to 2.2 kG (220 mTesla), 3% ripple at the wall

Plasma Sources: RF helicon, thermionic cathode (Ni/BaO)

Species: Ar, He, Ne, H, D

RF Helcion Plasma (Typical)

Density ~ 1019 - 1020 m-3

Te ~ 3 - 8 eV

Diameter: 10 - 20 cm (FWHM)

Gas fill pressure: 10-4 - 10-2 Torr

Cathode Plasma (Typical)

Density ~ 1018 - 7x1018 m-3

Te ~ 5 - 10 eV

Diameter: 10 - 20 cm (FWHM)

Gas fill pressure: 10-4 - 10-3 Torr

Physics Parameters

Ion sound speed, Cs ~ 103 - 104 m/s

Ion sound gyroradius, rs ~ 3 - 40 mm

Normalized rs /Ln ~ 2 - 10

Ion-neutral collision rate, nin ~ 105 - 103 s-1

Ion-neutral collision mean free path, lmfp,in ~ 5 - 50 cm

 

Helicon source in operation.  Helical antenna surrounds pyrex tube protruding from end of vacuum chamber.

Cathode plasma.

Cathode/heater assembly just prior to introduction into the vacuum chamber.  BaO coating, where electrons are emitted, is the white circle.

 


Current Projects

Additional information about each of the projects below can be found on Prof. Gilmore's publications and presentations page.

Basic Plasma Physics and Laboratory Astrophysics

1. Dynamics of the interaction of turbulence and sheared flows.  Many laboratory and fusion experiments have demonstrated that sheared plasma flows can suppress (or enhance) gradient-driven plasma fluctuations, including turbulence.  A well-known example of shear-suppression of turbulence is the H-mode (High confinement mode) in toroidal fusion plasmas.  Such interactions are also important in space and astrophysical plasmas.  In this project, we are investigating sheared flow/fluctuation dynamics in weakly nonlinear (chaotic) cases via controlled laboratory experiments and numerical modeling.  This is a collaboration with Prof. David Newman of the University of Alaska, and is funded by the National Science Foundation.

2. Feedback control of turbulent transport.  Plasma turbulence is known to caused increased levels of cross-field transport of heat and particles.  It has been demonstrate that transport barriers, such as in the H-mode, can be formed which exhibit strong flow shear.  However, particle transport across such barriers may actually be too low for a practical energy-producing fusion reactor.  Ideally, an active feedback control system could maintain a desired level of particle transport, perhaps by controlling the plasma flow profile.  In this project, we seek to demonstrate active control of cross-field particle transport by flow profile manipulation in a laboratory plasma using modern control engineering methods, such as extremum seeking.  This work is in collaboration with Prof. Eugenio Schuster of Lehigh University, and Prof. Andrew Ware of the University of Montana.  It is funded by the US Department of Energy Office of Fusion Energy Sciences.

3. Plasma Bubble Expansion Experiment (PBEX).  Magnetic relation is a very important process in plasmas in general.  One instance in astrophysics where magnetic relaxation is thought to be important is in the relaxation of astrophysical jets/radio lobes as they expand into the intergalactic medium plasma.  In particular, there may be poloidal to toroidal flux conversion in this process, which is important in the transport of magnetic fields into the intergalactic medium.  In this project, a compact coaxial plasma gun is used to generate a compact object (magnetized plasma bubble or spheromak), which is injected into the HelCat background plasma.  The relaxation of the bubble plasma and magnetic field are studied.  The purpose is to compare with and validate numerical MHD models of radio lobe relation.  This project is a collaboration with Drs. Scott Hsu, Hui Li, and Wei Li of Los Alamos National Laboratory.

4. Control of Plasma Flow Profiles by Electrode Biasing in HelCat.  These experiments seek to understand how plasma flow profiles (azimuthal and axial) can be controlled using biased grid and ring electrodes, which generate radial electric fields and affect field-aligned currents.  The goal is to develop both a practical empirical understanding of how to manipulate flows, as well as a first principles understanding of the nonlinear physics involved.

Fusion Energy

Our group also specializes in diagnostics (measurements) in high temperature plasmas for fusion energy.  We have established off-site collaborations with the following fusion experiments.

1. The Magnetized Target Fusion Experiment (MTF) being undertaken by Los Alamos National Laboratory (LANL), the US Air Force Research Laboratory (AFRL) (at the Shiva Star pulsed power facility in Albuquerque), and others.  MTF has the promise to be a relatively cheap and low cost path to fusion energy.  MTF is one of a class of fusion energy concepts, called magneto-inertial fusion (MIF), which seek to combine attributes of both inertial confinement fusion and magnetic confinement fusion by imploding magnetized "target" plasmas (compact toroids).  Our group is working on plasma diagnostics (visible light inerferometry), and well as developing a plasma gun to "preionize" the target plasma.  This work is funded by AFRL and the US Department of Energy EPSCor program.

2. Plasma Liner Experiment (PLX).  The plasma liner experiment began in early 2010 at Los Alamos National Laboratory (LANL).  This experiment seeks to demonstrate the formation of an imploding plasma spherical shell ("liner") using a spherical array of hyper-velocity (Mach number, M ~ 20 - 50) plasma guns.  The goal is to demonstrate a peak stagnation pressure of 0.1 Mbar, as a first step in higher pressures required for magneto-inertial fusion (~ 10 Mbar).  Our group is primarily responsible for the plasma diagnostics.  This project is a collaboration primarily between the LANL P-24 Plasma Physics group, HyperV Technology Corp., UNM, and Prof. Jason Cassibry at the University of Alabama, Huntsville.  This work is funded by US Department of Energy Office of Fusion Energy Sciences high energy density laboratory physics program.

3. The Polywell Fusion Experiment at the Energy Matter Conversion Corp. (EMC2). Polywell fusion is an innovative confinement concept for fusion energy that utilizes a combination of electrostatic plasma confinement (of ions) and 3D magnetic cusp confinement (of electrons).  Our group is fielding millimeter wave diagnostics of plasma density.

Space Physics/Space Weather

Additionally, Prof. Christopher Watts heads up collaborations for our group in space plasma physics and space weather (ionospheric, magnetospheric, and solar physics).  These collaborations include work with:

1. The  Air Force Space Weather Center of Excellence in Albuquerque.

2. The Long Wavelength Array (LWA) radio telescope being built and operated by UNM and others.  Our group (Prof. Watts) is responsible for modeling of the ionospheric plasma effect on received radio signals.

For more information on these projects, please see the UNM PFSL web page.

 


Personnel

Faculty:

Mark Gilmore (Associate Professor)

Alan Lynn (Research Assistant Professor)

Christopher Watts (Research Professor)

                            

Graduate Students:

Ryan Clark (M.S. ECE Dept.)

Kevin Davis (M.S. ECE Dept.)

Tiffany Hayes (M.S., Physics Dept.)

Ralph Kelly (Ph.D., ECE Dept.)

Elizabeth Merrit (Ph.D., Physics Dept.)

Steven Nelson (Ph.D., ECE Dept.)

Shuangwei Xie (Ph.D., ECE Dept.)

Lincan Yan (Ph.D., ECE Dept.)

Yue Zhang (Ph.D., ECE Dept.) 

   

Undergraduate Students:

Jaksa Osinski (Physics)

UNM Plasma and Fusion Science Group, June 2010.  Front row, L to R: Tiffany Hayes, Shuangwei Xie, Alan Lynn, Ryan Clark, Back Row L to R: Yue Zhang, Kevin Davis, Lincan Yan, Ralph Kelly, Mark Gilmore, Jaksa Osinski.  Background: HelCat helicon plasma.  Not pictured: Christopher Watts, Liz Merritt, Steven Nelson.


Alumni

 

Waylon Clark, MS in Optical Sciences, May 2007.  Thesis Title: Analysis of a Laser Induced Plasma in High Pressure SF6 Gas for High-Voltage, High-Current Switching.

Naga Devarapali, MS in EE, December 2006.  Thesis Title: 120 GHz Tracking Interferometer for the Triggered Plasma Opening Switch.

Janus Herrera,  M.S. in Electrical Engineering with a Manufacturing Option, May 2008.  Project Title: Design and Construction of A Chemical Delivery System for Atmospheric Pressure Plasma Materials Processing and Development of an Anti-Static Treatment for Polypropylene. 

Dan Jackson, M.S. in EE, December 2005.  Thesis Title: Design, Analysis, and Implementation of an Ion Collection Diagnostic for the Triggered Plasma Opening Switch.

Prashanth Kumar, MS in EE, December 2006.  Thesis Title: Characterization of the Dose Effect in Secondary Electron Emission. 

Jeremy Martin, Ph.D. in EE, May 2008.  Thesis Title: Precision Electron Flow Measurements in a Disk Transmission Line.

Steven Nelson, M.S. in EE, May 2010.  Thesis title: A Stochastic Ensemble Forecast Model for Geosynchronous Relativistic Electron Fluxes.

Priyanka Ram, M.S. in EE, December 2006.

Steven Will, MS in EE, December, 2005.  Thesis Title: Design and Construction of the Active Control of Turbulent Transport (ACTT) Plasma Device.

Nate Zameroski, MS in EE, May 2004.  Thesis Title: Effects of Surface Conditioning, Morphology, and Temperature on Secondary Electron Emission. 

 

Undergraduate Student Alumni:

Travis Brooks (Nuclear Engineering)

Marco Cueto

Mike Curry

Jake Hollowell

Emil Kadlec

Dennis Kim

Ricardo Magallanes

Ryan Molecke

Laurel Roberson

Andy Sanchez

Emilie Steinhoff (Chemistry)

 

Former High School Students:

Joseph Krietenger, La Cueva High School, mentorship, Spring 2008

Grant Hielman, La Cueva High School, summer 2007 intern

Jaksa Osinski, Albuquerque Academy, summers 2007 and 2008 intern

Will Volock, Cibola High School and ABQ Career Enrichment Center, Summer 2005

 

(Almost) brand new UNM Plasma and Fusion Science Group in an (almost) new laboratory, February 2005.  Left to right: Priyanka Ram, Alan Lynn, Shuangwei Xie, Steve Will, Mark Gilmore, Janus Herrera.

 

 


For More Information

Contact Prof. Mark Gilmore, gilmore@eece.unm.edu, for more information about the laboratory.


Last updated: June-04-2010