Energy transport in magnetic fusion devices

Thesis proposal for the 2015-2017 Ph.D. cycle
1) Program where the main part of activity will be realized
2) Thesis title:
Energy transport in magnetic fusion devices
3) Thesis supervisor
Rita Lorenzini
4) Group/s that will be involved in the program
FC and FB
5) Thesis abstract (max 600 characters)
This thesis is in the field of transport analyses in magnetically confined plasmas.
The work will be performed mainly on RFX-mod data and requires data analyses and data modeling with the
transport code ASTRA e the Kinetic Transport Algorithm code for neutrals KN1D.
Main aim of the thesis is to describe energy confinement and transport in the Reversed Field Pinch plasmas of
RFX-mod, comparing Hydrogen and Deuterium performances.
The energy transport will be studied considering both ion and electron channels.
Transport analyses are foreseen also for tokamak discharges using RFX-mod tokamak and COMPASS
tokamak plasmas. In the case of COMPASS plasma an extensive use of physics based model is foreseen.
The thesis is then composed by two main items:
 Analyses of fast neutral spectra measured by Neutral Particle Analyser (NPA) diagnostics and
reconstruction of ion temperature profiles in RFX-mod (RFP and tokamak plasma) and COMPASS
 Electron and ion energy transport studies in tokamak and reversed field pinch magnetic configurations
by means of the ASTRA code
6) External
 collaborations (existing or to be started), which might involve the Ph.D. student (if any)
Collaboration with COMPASS tokamak
7) Preliminary list of milestones for each of the three years
Electron energy transport studies in Hydrogen and Deuterium discharges with ASTRA code to compare
the performances of electron transport barriers.
Implementation of KN1D code and comparison with results of Monte Carlo code NENE.
Analyses of NPA data to compare Deuterium and Hydrogen ion temperature in QSH and MH plasmas
using KN1D/NENE codes.
Ion and electron energy transport analyses in Hydrogen and Deuterium RFP discharges in RFX-mod.
Starts of the analyses of NPA data in COMPASS tokamak.
Ion and electron energy transport analyses in Hydrogen and Deuterium tokamak discharges in RFXmod.
Ion and electron energy transport analysis in COMPASS device using tokamak physics based models.
8) Description of the research project (max 8000 characters)
Starting from the last two months of 2013 the RFX-mod experiment will be operated using Deuterium
(D) instead of Hydrogen (H) as filling gas.
These experiments offer the opportunity to characterize the dependence of RFX-mod plasma
performances on the isotope mass, as already done in tokamak and stellarator devices.
This project is aimed at comparing energy confinement and transport in RFX-mod H and D plasmas.
The energy confinement and transport will be studied considering both electron and ion channel in
Multiple Helicity and Quasi Single Helicity discharges.
The activity of this thesis will start studying the electron energy transport by means of ASTRA transport
code in order to compare thermal electron conductivity  profile in H and D.
In the Quasi Single Helicity state it is likely to observe the formation of electron Internal Transport
Barriers where  reaches values of few m2s-1.
The value of  in H discharges will be re-calculated taking into account the collisional transfer of
energy from electron to ions and compared to that of D discharges.
Regarding the ion channel the activity will start analyzing the data measured by the Neutral Particle
Analyzer to determine ion temperature profile. The present temperature reconstruction tool is based
on the neutral density and energy profile calculated with the Monte Carlo code NENE. The tool will be
integrated with the 1D Kinetic Transport Algorithm code for neutrals KN1D, whose simulation will be
compared to NENE outputs.
Once implemented the KN1D code the reconstruction tool will be used to calculate the ion
temperature in D discharges.
The results will be compared to H profiles and will feed ASTRA transport code to analyze energy
transport. First of all interpretative analyses to determine transport coefficients will be performed.
This type of analysis has, as a side effect, the possibility of detecting the eventual presence of an
anomalous ion heating.
Then we tried to use physics based model (e.g Microtearing for Transport Barrier) to obtain more
insight in the phenomena that drive transport.
An analogous analysis is also planned for tokamak plasmas. Regarding tokamak analyses collaboration
with COMPASS tokamak, where the ASTRA transport code is used to analyze transport and a NPA
diagnostic is used to measure the ion temperature, is foreseen.
This part of the work aims at using tokamak physics based model (e.g. ITG transport model) to analyze
the behavior of electron/ion temperature.
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