ER15-CEA-09

From ERwiki

(Difference between revisions)
Jump to: navigation, search
(Kinetic modelling of runaway electron dynamics)
(Kinetic modelling of runaway electron dynamics)
 
(34 intermediate revisions not shown)
Line 4: Line 4:
'''''Principal Investigator:'''''
'''''Principal Investigator:'''''
-
[mailto:yves.peysson@cea.fr Yves Peysson (CEA)]
+
Yves Peysson (CEA)
'''''Project Participants:'''''
'''''Project Participants:'''''
-
[mailto:ganastas@central.ntua.gr Girogos Anastassiou (NTUA)],  
+
Girogos Anastassiou (NTUA),  
-
[mailto:jean-francois.artaud@cea.fr Jean-François Artaud (CEA)],
+
Jean-François Artaud (CEA),
-
[mailto:budai8adam@hotmail.hu Adám Budai (BME)],
+
Adám Budai (BME),
-
[mailto:joan.decker@epfl.ch Joan Decker (CRPP)],
+
Joan Decker (CRPP),
-
[mailto:embreus@student.chalmers.se Ola Embréus (CU)],
+
Ola Embréus (CU),
-
[mailto:tunde@chalmers.se Tünde Fülöp (CU)],
+
Tünde Fülöp (CU)],
-
[mailto:eeroh@chalmers.se Eero Hirvijoki (CU)],
+
Eero Hirvijoki (CU),
-
[mailto:kyriakos@central.ntua.gr Kyriakos Hizanidis (NTUA)],
+
Kyriakos Hizanidis (NTUA),
-
[mailto:gkomin@central.ntua.gr Yannis Kominis (NTUA)],
+
Yannis Kominis (NTUA),
-
[mailto:taina.kurki-suonio@aalto.fi Taina Kurki-Suonio (AU)],
+
Taina Kurki-Suonio (AU),
-
[mailto:pwl@ipp.mpg.de Philipp Lauber (IPP-Garching)],
+
Philipp Lauber (IPP-Garching),
-
[mailto:lohner.roland@gmail.com Roland Lohner (BME)],
+
Roland Lohner (BME),
-
[mailto:mlynar@ipp.cas.cz Jan Mlynár (IPP-Prag)],
+
Jan Mlynár (IPP-Prag),
-
[mailto:sarah.newton@ccfe.ac.uk Sarah Newton (CCFE)],
+
Sarah Newton (CCFE),
-
[mailto:emelie.nilsson@cea.fr Emelie Nilsson (CEA)],
+
Emelie Nilsson (CEA),
-
[mailto:ppg@ipp.mpg.de Gergely Papp (IPP-Garching)],
+
Gergely Papp (IPP-Garching),
-
[mailto:pokol@reak.bme.hu Gergo Pokol (BME)],
+
Gergo Pokol (BME),
-
[mailto:francois.saint-laurent@cea.fr François Saint-Laurent (CEA)],
+
François Saint-Laurent (CEA),
-
[mailto:cristian.sommariva@cea.fr Cristian Sommariva (CEA)],
+
Cristian Sommariva (CEA),
-
[mailto:stahla@chalmers.se Adam Stahl (CU)],
+
Adam Stahl (CU),
-
[mailto:panosz@central.ntua.gr Panagiotis Zestanakis (NTUA)],
+
Panagiotis Zestanakis (NTUA)
'''''Participating Research Institutions:'''''
'''''Participating Research Institutions:'''''
Line 47: Line 47:
[mailto:cedric.reux@cea.fr Cédric Reux (CEA)],  
[mailto:cedric.reux@cea.fr Cédric Reux (CEA)],  
-
'''''Meeting:'''''
+
'''''EUROFUSION Publication rules:'''''
-
<pre style="color: red;font-weight: bold;font-size: 250%;">The 3rd Runaway Electron Meeting (REM 2015) will takes place the 17-19th of June 2015 at Pertuis, France</pre>.
+
EUROFusion publication rules by Kinga Kàl, [[File:kgal_20150129_ER.pdf]]<br>
 +
 
 +
'''''Meeting:'''''
-
All details (registration, accommodation, program,... ) will be soon available [http://erp.runaway.free.fr/REM_2015/registration.htm here ].
+
<p style="color: red;font-weight: bold;font-size: 130%;">The 5th Runaway Electron Meeting (REM 2017) will take place the 5-8th of June 2017 at Liblice, Czech Republic</p>
 +
All details (registration, accommodation, program,... ) are available [https://indico.ipp.cas.cz/event/6/registration/ here ].
'''''EURO-fusion support:'''''
'''''EURO-fusion support:'''''
-
For participants to the meeting who are also parts of the EURO-fusion Enabling Research project ER15-CEA-09, some travel expenses may be funded by the project ER15-CEA-09. Please fill the standard Mission Application form which is available [http://users.jet.efda.org/eurofusion-mission-application-e-form here ].
+
For participants of the EURO-fusion Enabling Research project ER15-CEA-09 who wants to travel for the project (REM meeting, collaboration,...) and get some funding, please fill the standard Mission Application form which is available [http://users.jet.efda.org/eurofusion-mission-application-e-form here ]. If people sit in the fusion lab (previous Associations) the users website should be accessible without any password. Outside a password is needed that can be applied for  [http://www.efda.org/collaborators/remote-data-access/ here].
 +
 
 +
'''''Interim report:'''''
 +
 
 +
The last interim activity report 2016 of ER15-CEA-09 that has been recommended and approved can be downloaded [[File:WPENR_AWP15_interim_report_CEA-09-2016.pdf‎ ]].
'''''Objectives:'''''
'''''Objectives:'''''
Line 97: Line 104:
[20] S. D. Pinches et al., Comput. Phys. Commun. 111, 131 (1998)<br>
[20] S. D. Pinches et al., Comput. Phys. Commun. 111, 131 (1998)<br>
[21] M. Landerman, A. Stahl and T. Fülöp, Numerical calculation of the runaway electron distribution function and associated synchrotron emission, Comp. Phys. Communications, 2014, 185, pp 847-855<br>
[21] M. Landerman, A. Stahl and T. Fülöp, Numerical calculation of the runaway electron distribution function and associated synchrotron emission, Comp. Phys. Communications, 2014, 185, pp 847-855<br>
 +
 +
'''''Documents:'''''<br>
 +
 +
Interim report ER15-CEA-09 (2015-12) [[File:WPENR_AWP15_interim_report_CEA-09.pdf]]<br>
 +
Mid-term report ER15-CEA-09 (2016-06)  [[File:WPENR_AWP15_midterm_report_CEA-09.pdf]]<br>
 +
Interim report ER15-CEA-09 (2016-12) [[File:WPENR_AWP15_interim_report_CEA-09-2016.pdf‎]]<br>
 +
 +
<hr>
 +
<u>Joint Work Program JET1 AND MST1 General Planning Meeting 19-23 January 2015, Lausanne, Switzerland</u>
 +
 +
Analysis of disruption and RE proposals for MST, Piero Martin, [[File:2015 GPM 1.3_2 piero.pptx]]<br>
 +
Introduction to the disruption JET/MST program, Piero Martin, [[File:2015 GPM disrupion intro piero 2.pptx]]<br>
 +
Disruptions and run-aways, Emmanuel Joffrin, [[File:GPM2015-Joffrin.ppt]]
 +
<hr>

Latest revision as of 11:29, 17 February 2017

Kinetic modelling of runaway electron dynamics

Principal Investigator:

Yves Peysson (CEA)

Project Participants:

Girogos Anastassiou (NTUA), Jean-François Artaud (CEA), Adám Budai (BME), Joan Decker (CRPP), Ola Embréus (CU), Tünde Fülöp (CU)], Eero Hirvijoki (CU), Kyriakos Hizanidis (NTUA), Yannis Kominis (NTUA), Taina Kurki-Suonio (AU), Philipp Lauber (IPP-Garching), Roland Lohner (BME), Jan Mlynár (IPP-Prag), Sarah Newton (CCFE), Emelie Nilsson (CEA), Gergely Papp (IPP-Garching), Gergo Pokol (BME), François Saint-Laurent (CEA), Cristian Sommariva (CEA), Adam Stahl (CU), Panagiotis Zestanakis (NTUA)

Participating Research Institutions:

Aalto University, Finland, BME – NTI, Budapest, Hungary, Chalmers University, Göteborg, Sweden, Culham Centre for Fusion Energy, UK, Institute for Plasma Physic, Prag, Czech Republic, IRFM-CEA, Cadarache, France, Max-Planck Institute for Plasma Physics, Garching, Germany, National Technical University of Athens, Greece, CRPP, Swiss Federal Institute of Technology, Switzerland

External Participants:

Eric Nardon (CEA), Cédric Reux (CEA),

EUROFUSION Publication rules:

EUROFusion publication rules by Kinga Kàl, File:Kgal 20150129 ER.pdf

Meeting:

The 5th Runaway Electron Meeting (REM 2017) will take place the 5-8th of June 2017 at Liblice, Czech Republic

All details (registration, accommodation, program,... ) are available here .

EURO-fusion support:

For participants of the EURO-fusion Enabling Research project ER15-CEA-09 who wants to travel for the project (REM meeting, collaboration,...) and get some funding, please fill the standard Mission Application form which is available here . If people sit in the fusion lab (previous Associations) the users website should be accessible without any password. Outside a password is needed that can be applied for here.

Interim report:

The last interim activity report 2016 of ER15-CEA-09 that has been recommended and approved can be downloaded File:WPENR AWP15 interim report CEA-09-2016.pdf.

Objectives:

One of the most remarkable characteristics setting fusion plasmas aside from neutral gases is that the collisional friction force acting on suprathermal electrons decreases with the electron velocity. Therefore, in the presence of a parallel electric field larger than some critical value, electrons with sufficient initial velocity will be continually accelerated. The so-called runaway electrons may reach energies in the 10 MeV range [1,2].

As the critical field is proportional to the electron density, runaway electrons are generated in plasma regions of low density and/or large electric field. In particular, they can be produced in great numbers during plasma disruptions, when the rapid cooling associated with a thermal quench gives rise to a large parallel electric field. These runaways are sometimes rapidly lost during the subsequent current quench, and sometimes form a runaway beam [3]. This beam, which can carry a significant fraction of the initial current, can become unstable and hit the wall over a relatively small area, thereby creating great damage [4].

Understanding the runaway dynamics has been identified as a critical issue for ITER [5]. In present-day tokamaks also, the danger of runaway-induced damage often limits the range of operation parameters. The following questions can be formulated regarding runaway electron dynamics during disruptions: Under which conditions do disruptions give rise to a runaway beam? Can this process be prevented or mitigated ? Is it possible to transport runaway electrons as soon as they are generated ? If a runaway beam nonetheless forms, what are its characteristics, i.e. what is the electron energy distribution ? Is it possible to slow it down progressively ? What are the effects of mitigation techniques such as massive material injection ?

Answering all these questions ultimately requires a complete disruption simulator solving both a kinetic equation for the runaway dynamics, and a fluid-MHD evolution including massive gas or pellet injection, ionization physics, impurity transport, etc. This is a long term objective for the community. In the near future, it is necessary to improve separately both the kinetic description of runaways, which is the subject of the present project.

During disruptions, the generation of runaway electrons can be dominated by the so-called “avalanche process”, in which a head-on collision between an existing runaway electron and a slow electron can kick the latter into the runaway region [6]. Because the primary runaway electron is ultra relativistic, it can transfer a significant fraction of its initial energy to the secondary electron while keeping a velocity near the speed of light, thereby remaining in the runaway region.

Runaway electrons can therefore “multiply” through this avalanche process with an exponential growth. The secondary runaway generation being proportional to the density of existing runaway, the runaway dynamics can be highly non-linear. Consequently, small variations in the balance between runaway generation and runaway transport can lead to large differences in the resulting density of runaways, and determine whether a significant runaway beam is formed or not [3].

Yet, in most existing runaway models [7], the various processes governing the electron response to a parallel electric field – Spitzer (ohmic ) heating [8], Dreicer (primary) runaway generation [1,2], Rosenbluth avalanche (secondary) runaway generation [6], hot-tail formation [9] – are calculated separately, even though these mechanisms are all described by the same electron distribution function and are thus interdependent. In addition, runaway transport due to turbulence [10], resonant magnetic perturbation [11,12,13], kinetic instabilities [14, 15], etc, is often calculated based on a given electron distribution without any self-consistent interaction with the runaway generation.

The framework required to calculate runaway electron generation and transport self consistently is the electron kinetic equation. The linearized 3D relativistic finite-difference Fokker-Planck electron guiding-center code LUKE was primarily developed to calculate current-drive by RF waves [16,17]. Yet, with non-uniform grids and arbitrary time steps, it is particularly suited to the calculation of runaway dynamics. This project intends to make use of the code LUKE, GO [7] and CODE [21] and other tools to develop a new framework for realistic and quantitative runaway simulations.

References :
[1] H. Dreicer, Electron and Ion Runaway in a Fully Ionized Gas, I. Phys. Rev. 115, 238 (1959).</ref>
[2] H. Dreicer. Electron and Ion Runaway in a Fully Ionized Gas, II. Phys. Rev. 117, 329 (1960).
[3] T. Fülöp, H.M. Smith, G.I. Pokol. Magnetic field threshold for runaway generation in tokamak disruption. Phys. Plasmas 16, 022502 (2009).
[4] R. Nygren, et al. Runaway electron damage to the Tore Supra phase III outboard pump limiter. J. Nucl. Materials 241, 522 (1997).
[5] T.C. Hender, et al. Progress in the ITER physics basis. Nucl. Fusion 47, S128 (2007).
[6] M.N. Rosenbluth and S.V. Putvinski. Theory for avalanche of runaway electrons in tokamaks. Nucl. Fusion 37, 1355 (1997).
[7] T. Fehér, H. M. Smith, T. Fülöp, K. Gal. Simulation of runaway electron generation during plasma shutdown by impurity injection in ITER. Plasma Phys. Control. Fusion 53, 035014 (2011).
[8] R.S. Cohen, L. Spitzer and P. Routly. The electrical conductivity of an ionized gas. Phys. Rev. 80, 230 (1950).
[9] H. Smith, P. Helander, L.-G. Eriksson, and T. Fülöp. Runaway electron generation in a cooling plasma. Phys. Plasmas 12, 122505 (2005).
[10] R. Yoshino and S. Tokuda. Runaway electrons in magnetic turbulence and runaway current termination in tokamak discharges. Nucl. Fusion 40, 1293 (2000).
[11] G. Papp, M. Drevlak, T. Fülöp, P. Helander. Runaway electron drift orbits in magnetostatic perturbed fields. Nucl. Fusion 51, 043004 (2011).
[12] G. Papp, M. Drevlak, T. Fülöp and G. I. Pokol. The effect of resonant magnetic perturbations on runaway electron transport in ITER. Plasma Phys. Control. Fusion 54, 125008 (2012).
[13] L. Laurent and J. M. Rax Stochastic Instability of Runaway Electrons in Tokamaks, Europhys. Lett., 11 (3), pp. 219-224 (1990)
[14] A. Komar, G. I. Pokol and T. Fülöp. Electromagnetic waves destabilized by runaway electrons in near-critical electric fields. Phys. Plasmas 20, 012117 (2013).
[15] J.-M. Rax, L. Laurent and D. Moreau, Stochastic Instability of Relativistic Runaway Electrons Due to Lower Hybrid Waves, Europhys. Lett., 15 (5), pp. 497-502 (1991)
[16] J. Decker and Y. Peysson. DKE: A fast numerical solver for the 3D drift kinetic equation. Euratom-CEA Report EUR-CEA-FC-1736 (2004).
[17] Y. Peysson and J. Decker. Simulations of the rf-driven toroidal current in tokamaks. Fus. Sci.& Tech. 2014, 65, pp. 22-42.
[18] J. Decker and Y. Peysson and A. J. Brizard and F.-X. Duthoit, Orbit-averaged guiding-center Fokker-Planck operator for numerical applications, Phys. Plasmas, 2010, 17, 11, pp. 112513
[19] P. Lauber et al., J. Comput. Phys. 226/1, 447 (2007)
[20] S. D. Pinches et al., Comput. Phys. Commun. 111, 131 (1998)
[21] M. Landerman, A. Stahl and T. Fülöp, Numerical calculation of the runaway electron distribution function and associated synchrotron emission, Comp. Phys. Communications, 2014, 185, pp 847-855

Documents:

Interim report ER15-CEA-09 (2015-12) File:WPENR AWP15 interim report CEA-09.pdf
Mid-term report ER15-CEA-09 (2016-06) File:WPENR AWP15 midterm report CEA-09.pdf
Interim report ER15-CEA-09 (2016-12) File:WPENR AWP15 interim report CEA-09-2016.pdf


Joint Work Program JET1 AND MST1 General Planning Meeting 19-23 January 2015, Lausanne, Switzerland

Analysis of disruption and RE proposals for MST, Piero Martin, File:2015 GPM 1.3 2 piero.pptx
Introduction to the disruption JET/MST program, Piero Martin, File:2015 GPM disrupion intro piero 2.pptx
Disruptions and run-aways, Emmanuel Joffrin, File:GPM2015-Joffrin.ppt


Personal tools