PSFC Seminars

All Seminars are on Friday at 3pm, unless otherwise noted.
NW17-218, 175 Albany Street, Cambridge
For further information: info@psfc.mit.edu

May 24, 2019

The science and programs of the High-Energy-Density Science Center at LLNL

Frank Graziani

Lawrence Livermore National Laboratory

Graziani discusses the strengths and weaknesses of the various computational approaches and briefly touches on two recent advances that may hold promise to enhancing the current weaknesses. The talk ends with a discussion of the High Energy Density Sciences Center, which is an outreach organization at LLNL that is building a HEDP community through interactions of LLNL scientists withacademic collaborators.
 

3:00pm  |  NW17-218  |  Add to CalendarApple CalendarGoogleOutlookYahoo

Past Events

May 17, 2019

The effect of impurities on detachment, pedestal performance and global confinement

Livia Casali

General Atomics

Impurities in tokamaks, either originating from the wall or injected into the plasma with the aim of reducing power loads on divertor components, affect the pedestal and global confinement. As such, understanding the physics of such effects is vital for the operation of future devices.  At ASDEX Upgrade a reduction of the energy confinement has been observed with the introduction of the W metal wall attributed to the absence of a low-Z edge radiator. The confinement in AUG can be recovered with nitrogen seeding. The discussion of both AUG and DIII-D data aims to assess the impurity dynamics and their effects in high vs low Z wall machines.

3:00pm  |  NW17-218

May 10, 2019

Gyrokinetic analysis and simulation of pedestal transport

David Hatch

University of Texas, Austin

An understanding of pedestal transport is indispensable to tokamak design, optimization, and operation. This presentation will report on a broad range of gyrokinetic pedestal transport studies including the ongoing FY19 theory performance target (TPT), whose goal is to identify the turbulent transport mechanisms, along with the corresponding heat and particle sources, that govern pedestal dynamics.  

3:00pm  |  NW17-218

May 3, 2019

Testing predictions of electron scale pedestal turbulence in DIII-D H-modes

Walter Guttenfelder

Princeton Plasma Physics Laboratory

This talk will present experimental and gyrokinetic analysis of transport in the edge pedestal region of DIII-D ELMy H-mode discharges. The analysis is performed for two discharges with different divertor geometry to clarify the role of transport vs. sources in setting the pedestal density and temperature profiles.

3:00pm  |  NW17-218

Apr 26, 2019

Role of reconnection in magnetic plasma turbulence

Stanislav Boldyrev

University of Wisconsin-Madison

Numerical simulations, observations, and analytic models suggest that strong magnetic plasma turbulence forms anisotropic sheared magnetic structures that are not necessarily associated with energy dissipation, rather, they appear in a broad range of scales. We argue that given large enough Reynolds number of turbulence, such magnetic structures may become unstable to the tearing modes thus initiating processes of magnetic reconnection.

3:00pm  |  NW17-218

Apr 19, 2019

Pulsed power science and applications on Sandia's Z Machine

Daniel Brian Sinars

Sandia National Laboratories

This talk will highlight ongoing research on Z in magneto-inertial fusion, dynamic materials, and radiation science, as well as work being done by academic partners as part of our Z Fundamental Science Program.

2:00pm  |  NW17-218

Apr 12, 2019

Observable consequences of saturation by stable modes

Paul Terry

University of Wisconsin-Madison

This talk will examine the growing list of observable consequences of the saturation of ion temperature gradient turbulence by stable modes.  These include the wavenumber spectrum of ITG turbulence, the scaling of its turbulence level with zonal flow damping rate, and the rate of heat flux decrease with beta in gyrokinetic simulations.

3:00pm  |  NW17-218

Apr 5, 2019

Fusion and laser plasma research interaction at LLE: status and future

Mike Campbell

Laboratory for Laser Energetics

A novel experimental platform, advanced diagnostics and simulation tools have been established at LLE and an advanced laser concept that has the potential to expand laser parameter space for all laser fusion approaches is under development. In addition to expand the opportunities for high energy density science, a new facility that includes two 30 Petawatt lasers has recently been proposed and will also be presented. 

3:00pm  |  NW17-218

Apr 1, 2019

Special Seminar: Integration of non-equilibrium gliding arc plasma in agriculture

Gregory Fridman

C&J Nyheim Plasma Institute, Drexel University

Cold plasma water purification and enrichment technology utilization in hydroponic system is discussed.  The technology can extend to other areas of agriculture as the antimicrobial chemicals produced in plasma rapidly kill pathogens and are safe for both plants and animals.
 

3:00pm  |  NW22-150

Mar 1, 2019

From SOL turbulence to planetary magnetospheres: computational plasma physics at (almost) all scales using the Gkeyll code

Ammar Hakim

Princeton Plasma Physics Laboratory

In this talk I will present algorithmic innovations and physics simulated by the Gkeyll code. In particular, I will focus on recent progress in implementing a  novel algorithm for EM gyrokinetics in the symplectic formulation; and progress in developing a robust semi-implicit algorithm for multi-fluid moment equations. Physics of turbulence in NSTX SOL will be presented, in particular, the statistics of blobs and heat-flux on divertor plates.

3:00pm  |  NW17-218

Feb 8, 2019

Measurement of RF electric fields relevant for heating and current drive

Elijah Martin

Oak Ridge National Laboratory

In this seminar, the diagnostic and associated experimental results obtained from an RF sheath test stand (IC), Tore Supra (LH) and Alcator C-Mod (LH) will be presented.  Future diagnostic plans for the RF sheath test stand (IC), WEST (LH) and DIII-D (LH and EC) will be discussed.

3:00pm  |  NW17-218

Sep 28, 2018

High-field tokamaks: From Alcator to ARC

Bob Mumgaard

Commonwealth Fusion Systems

The seminar will trace the history of the high-field approach from its inception to its hiatus and its revival via HTS superconductors. We'll examine the various limitations of high-field copper and HTS magnets and the characteristics of high-field tokamaks as a class evolving from the invention of tokamaks to today.  Then we'll look forward to explore the high-field tokamak power plants based on the ARC-concept as a class.  We'll compare and contrast the attributes of these ARC-like power plants with their ITER-like or ARIES-like counterparts. 

3:00pm

Sep 21, 2018

Building an open source Python software ecosystem for plasma physics

Nick Murphy

Harvard-Smithsonian Center for Astrophysics

In this talk, Nick Murphy will describe modern best practices for scientific computing that we are adopting in PlasmaPy [2], present PlasmaPy’s current and planned capabilities, and discuss how our community can work together to forge an open source software ecosystem in coming years.

3:00pm  |  NW17-218

Sep 19, 2018

Supporting stockpile stewardship with high-energy-density physics experiments

Alan Wan

Lawrence Livermore National Laboratory

This presentation summarizes the range of High-Energy-Density (HED) physics experiments that deliver data meeting the mission requirements for stockpile-stewardship-relevant physics issues in regime otherwise inaccessible with other facilities.  Key HED physics topics range from material properties at high-pressure and temperatures, to radiation transport and radiation hydrodynamics.

11:00am  |  NW17-218

Sep 14, 2018

CRF physics studies using the Large Plasma Device

Troy Carter

UCLA

An experimental campaign on the physics of ICRF waves has recently begun using the Large Plasma Device (LAPD) at UCLA. A new high-power (∼150 kW) RF system and antenna have been developed for excitation of large amplitude fast waves in LAPD. The source runs at a frequency of 1-5 MHz, corresponding to ∼1-10 fci, depending on plasma parameters. Recent work has focused on the structure and scaling of RF sheaths and convection cells near the antenna.

3:00pm  |  NW17-218

Jun 14, 2018

Collisionless plasma shocks: properties, interests and similarities to fluid shocks

Antoine Bret

Universidad de Castilla-La Mancha

A neutral fluid can sustain shockwaves where dissipation at the shock front is provided by binary collisions. In a plasma, collective effects can equally provide dissipation so that shockwaves can develop over length scales much shorter than the mean free path. Such shocks have been dubbed “collisionless shock”. After reviewing the mechanism of their formation, we will explain why they have been attracting so much attention in recent years. Finally, we will comment on the similarities and differences their offer with respect to fluid shocks.

3:00pm  |  NW17-218

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