PSFC Student Seminars

All Seminars are on Wednesday at 5:15pm, unless otherwise noted.
NW17-218, 175 Albany Street, Cambridge
For further information: info@psfc.mit.edu

Dec 5, 2017

Towards a quantitative comparison between electron scale turbulence experiment and simulation

Juan Ruiz Ruiz

PSFC

In this talk Ruiz will explain how electron scale turbulence can be studied experimentally and numerically in spherical tokamaks, emphasizing the importance of designing synthetic numerical experiments that mimic tokamak experimental measurements, called synthetic diagnostics, in order to validate plasma turbulence models against experiments. He will present his current efforts to design a synthetic diagnostic to study electron scale turbulence and the transport of electron heat in the National Spherical Tokamak eXperiment (NSTX).

5:00pm

Nov 28, 2017

Core turbulence and intrinsic rotation reversal hysteresis in tokamak plasmas

Norman Cao

PSFC

This work provides strong evidence against the long-standing conjecture that the LOC/SOC transition is indicative of a change in the dominant ion-scale drift-wave instability, and suggests the importance of subdominant modes in determining the qualitative behavior of plasmas.

5:00pm  |  NW17-218

Nov 21, 2017

Using secondary nuclear reaction products to infer the fuel areal density, convergence, and electron temperatures on OMEGA and the NIF

Brandon Lahmann

PSFC

In deuterium-filled inertial confinement fusion (ICF) implosions, DD-tritons can undergo secondary fusion reactions with the thermal deuterium plasma to create secondary DT neutrons. On the National Ignition Facility (NIF), both the primary reactions (via DD-neutrons) and the secondary DT neutrons are routinely measured from several lines of sights using neutron time of flight (nTOF) spectrometers. The ratio of these secondary and primary reactions are used to infer the areal density (ρR) and the convergence of the fuel region. Additionally, the shape of the secondary DT neutron spectra can be used to infer the final asymmetry of the imploded capsule. Convergences inferred using x-ray imaging techniques are consistently larger than those inferred by this secondary DT neutron technique. These apparent discrepancies are not currently understood, but potential explanations are discussed. This work is supported in part by the U.S. Department of Energy and Lawrence Livermore National Laboratory.

5:00pm  |  NW17-218

Nov 7, 2017

Turbulence in tokamaks and the validation of gyrokinetic codes

Alex Creely

PSFC

This talk will describe the methodology behind validation in general, and will then focus specifically on the validation of gyrokinetic simulations of fusion plasmas.  The emphasis will primarily be on the high level comparisons of different measurements, rather than the details of the simulations or of the experimental measurements themselves.

5:00pm  |  NW17-218

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