Seminars Autumn/Michaelmas Term 2016

PLASMA SEMINARS AND GROUP MEETINGS

The style of the seminars will be informal/chaotic/interactive, following the established tradition. The format of the presentations can be a tutorial on a topic of interest, a report on just completed/ongoing/just starting/potentially interesting research projects, a literature review, a lecture by a passing visitor or anything else worthwhile that anyone cares to suggest. The speakers will be interrupted freely and asked to defend themselves. For background reading, only the most relevant or the most recent references are posted; please follow the paper trail from there.

The schedule is subject to change on short notice, but what you see posted here is always up to date; the seminars are also announced via the department's seminar server (group meetings are not). Please email Alex Schekochihin if you would like to receive email updates on these seminars.

"Group meetings to discuss current affairs" will discuss current affairs (ongoing projects, new litearture etc.) as well as feature some presentations that are even more informal than seminars. They are open to all members of the Oxford Plasma Theory Group. While some expected contributions are pre-announced, everything is TBC and people wishing their work to be discussed can volunteer contributions without prior notice. Unlike for the seminars, there will not be full-spam-list email reminders of the group meetings.

Past seminar database: Autumn 2007; Winter-Spring 2008; Summer 2008; Autumn 2008; HT 2009; TT 2009; Summer 2009; MT 2009; HT 2009; TT 2010; Summer 2010; MT 2010; HT 2011; TT 2011; Summer 2011; MT 2011; HT 2012; TT 2012; Summer 2012; MT 2012; HT 2013; TT & Summer 2013; MT 2013; HT 2014; TT & Summer 2014; MT 2014; HT 2015; TT & Summer 2015; MT 2015; HT 2016; TT & Summer 2016

Autumn/Michaelmas Term of 2016

The seminars/group meetings will be on Thursday at 11:30 in 501 DWB, except where indicated otherwise below.
Note also the ALP Seminars (here is a list of all Physics seminars)

This term, the seminars and group meeting are organised by Michael Barnes and Alex Schekochihin, please contact them with any queries or if you wish to present something.

If you know exactly what you are going to do, what is the point of doing it? Pablo Picasso

Every line in your calculations ends with "=0". You are not making much progress! Kate Hammett
We don't do the calculation because we don't know the answer, we do it because we have a conscience. Bryan Taylor
Let's change the resolution on the Unknown. Gabe Plunk
Let me put it differently: suppose we had a reactor... Per Helander
Working together takes more than one person. Bill Dorland
We can't do ultraviolence to that square bracket. Ian Abel
Field lines are forever. Bryan Taylor
This is not really an ill-posed problem, this is not a problem at all. Paul Dellar
I am just doing mathematics at the moment, but it is mathematics that has some point. Bryan Taylor
The equivalent of God in MAST is MHD, which is global and all powerful. Anthony Field
I've got a fishbone coming up. Tim Horbury
We have crossed all the i's and dotted all the t's. Job's a good'un. Ian Abel
Let us not jump in front of the bandwagon! Anonymous
It's not the triviality, it's the emptiness of it that bothers me. Bryan Taylor

It is better to be roughly right than precisely wrong. Maynard Keynes

This is a very inefficient way of achieving nothing. François Rincon
We Hankel all the way in and then Hankel all the way out. Joseph Parker
For the sake of fairness, let me mention that some people have objections to this, none of which are particularly valid. Chris Chen
Yes, Steve, you have always known what we have only just figured out. Alfred Mallet
This is more or less right. Perhaps less. Alfred Mallet
You go ahead with your argument. I'll think. Steve Cowley
Too simple? At the end of my talk, you will beg for simplicity! Andrey Beresnyak
The point is not the point! Anonymous
This is why I am presenting this here and nowhere else: nothing is solved! Ian Abel
This calculation is not intellectual masturbation: there's no orgasm. Anonymous
There are many big Buts here... I like big Buts. Anonymous
Previous studies of this problem have been either unsatisfactory or limited in scope.---What is the difference between these?---This means either wrong or irrelevant.
Anatoly Spitkovsky, Michael Medvedev and Steve Cowley (in conversation)
I don't give a damn about astrophysics, explain to me what is going on. Anatoly Spitkovsky

[these quotes are from Oxford plasma seminars and Vienna meetings]

Wk	Date	Time & place	Speaker & Topic	Background reading	Comings and goings (incl. visitors in town)
	Thu 1 Sept	11:30 Fisher Rm	Plasma Group Meeting (organised by MICHAEL) Group discussion. New arrivals: Yohei Kazwazura and Adwiteey Mauriya (see Background Reading if you want to read up on their past research).	arXiv:1602.01165 PoP 22, 112503 (2015) J. Phys. A 47, 465501 (2014) PoP 19, 082513 (2012) PoP 19, 012305 (2012) PRE 82, 066403 (2010) ApJ 790, 125 (2014)	Yohei Kawazura joins the group as STFC PDRA Adwiteey Mauriya (IST, Lisbon) joins the group as a visiting student (with M. Barnes & F. Nave) Nicolas Christen joins the group as DPhil student (to work with M. Marnes)
	Mon 5 Sept	11:30 501 DWB	Plasma Seminar (organised by ALEX) Eugene Churazov (MPA Garching) --- (1) Update on Hitomi results on galaxy-cluster turbulence and their physics implications (2) Not that long time ago in the nearest galaxy: 3D slice of molecular gas revealed by a 110 years old flare of Sgr A* (and a programme for the next few hundred years of X-ray observations of our Galaxy)	(1) Nature 535, 117 (2016) (2) preprint from author on request	Eugene Churazov (MPA Garching)
	Thu 15 Sept	11:30 501 DWB	Plasma Group Meeting (organised by MICHAEL) Summer projects update: Paolo Abiuso & Michael Barnes --- Pair plasmas heating		Paolo Abiuso (SNS) finishes his summer internship with M. Barnes
	Thu 22 Sept	11:30 501 DWB	Plasma Seminar (organised by ALEX) Yohei Kawazura (Tokyo--->Oxford) --- Particle acceleration in a laboratory magnetosphere	arXiv:1602.01165 PoP 22, 112503 (2015) a version of slides	Jason Parisi and Valerian Chen join the group as DPhil students (to work with F. Parra)
	26-30 Sept	Gyrokinetic Theory Working Group Meeting in Madrid
	Thu 29 Sept	No seminar
0	Thu Oct 6	11:30 501 DWB	Plasma Seminar (organised by MICHAEL) Yohei Kawazura (Tokyo--->Oxford) --- Action principle for relativistic extended magnetohydrodynamics	arXiv:1611.06036	Plamen Ivanov joins the group as DPhil student (to work with A. Schekochihin)
I	Thu Oct 13	11:30 501 DWB	Plasma Seminar (organised by ALEX) Romain Meyrand (SSL Berkeley & LPP Paris) --- Waves and turbulence in magneto-fluid	JFM 770, R1 (2015) PRL 116, 105002 (2016)	Romain Meyrand (SSL, Berkeley)
I	Fri 14 Oct	14:00 rm 277 7 Keble Rd	Oxford e-Research Centre Seminar: Colin Roach (CCFE) --- Fusion, plasma turbulence and computational challenge		Romain Meyrand (SSL, Berkeley)
II	Thu Oct 20	11:30 501 DWB	Plasma Group Meeting (organised by MICHAEL) Michael Barnes --- Tutorial lecture: Overview of tokamak transport and scaling laws for tokamak turbulence This a crash course aimed especially at graduate students. The following reading is recommended: 1) Students should be familiar with random walks and diffusion; if you are not please educate yourselves 2) Multiscale GK theory: a comprehensive review is Abel et al. (2013) Rep. Prog. Phys. 76, 116201 (you're not expected to read this fully before the lecture, but do take a look); see also PPCF 50, 065014 (2008) for another now classic treatment; the baby version of GK (slab) very good for initial learning: ApJ 651, 590 (2006) 3) Multiscale GK numerics: PoP 17, 056109 (2010) 4) Critical balance in fusion context: PRL 107, 115103 (2011) 5) Scaling laws for turbulent heating: PRL 109, 185003 (2012)	look on the right Michael's slides (pptx)
III	Thu Oct 27	11:30 501 DWB	Plasma Group Meeting (organised by ALEX) Alex Schekochihin --- Update on MAST turbulence: subcritical transition, electron collisionality scaling/zonal flows, etc. (based on the theses of G. Colyer, F. van Wyk & M. Fox)	arXiv:1607.06752 arXiv:1607.08173 arXiv:1609.08981 another preprint on request from F. van Wyk	Ian Abel (Chalmers) G. Ravindra Kumar (Tata Inst.) Alfred Mallet (UNH) Anvar Shukurov (Newcastle) Michael Fox
III	Fri Oct 28	15:30 501 DWB	Plasma Seminar (organised by GIANLUCA & ALEX) G. Ravindra Kumar (Tata Institute) --- Ultrafast plasma dynamics and giant magnetic fields in intense laser-matter interactions High intensity, ultrashort light pulses (>10^18 W/cm^2, femtosecond duration) are revolutionising science and technology in very exciting ways, whether it is laboratory simulation of astrophysical phenomena, relativistic optics, table-top particle acceleration, real-time X-ray diffraction of the condensed phase or medical therapies for cancer. All these phenomena rely crucially on the generation and transport of relativistic electrons in a target. This talk will present studies of the transport of the mega-ampere current of these electrons through dense matter, using ultrafast pump-probe experiments. We will look at the evolution of multi-megagauss magnetic pulses at femtosecond temporal and micron spatial resolution in the plasma [1, 2]. We will examine the electron filamentation process and the turbulent behavior of the magnetic field [1, to be published]. Similarities between our results and astrophysical observations indicate the rich scope offered by table top terawatt lasers for pursuing laboratory astrophysics. We will also touch upon our studies on the ultrafast dynamics of femtosecond laser generated plasma involving Doppler spectrometry [3] and Cherenkov emission.	[1] PNAS 109, 8011 (2012) [2] PRL 108, 235005 (2012) [3] PRL 114, 115001 (2015)
IV	Thu Nov 3	11:30 501 DWB	Plasma Seminar (organised by ALEX) Andrey Beresnyak (NRL) --- Charged particles in turbulence Most astrophysical objects are sources of non-thermal emission produced by energetic particles. Particles may be accelerated in shocks or current layers or just in turbulence. Even in shocks, which are very efficient accelerators, interaction with turbulence is critical because particles must scatter through self-generated turbulence. Speaking of turbulence, a common way to look at it as an agent that facilitates diffusion and mixing. I will show, however, that turbulence can un-mix particles, creating free energy in the initial equilibrium distribution. This curious property depends only on the geometry of the magnetic field lines, e.g. field lines can act as a Maxwellian demon for particles [1]. Likewise, turbulence had been imagined as a completely random process in which particles can only be accelerated by the slow second-order process. In fact, recently we found a surprising analytical connection between first order acceleration rate and a certain statistical property of turbulence which is often non-zero [2]. In other words, turbulence is not random and it can, volumetrically, accelerate or decelerate particles in the first order process.	[1] ApJ 767, 39L (2013) [2] ApJ 819, 90 (2016)	Andrey Beresnyak (NRL) Adwiteey Mauriya returns to Lisbon
V	Thu Nov 10	11:30 501 DWB	Plasma Group Meeting (organised by ALEX) Felix Parra --- Stellarators close to omnigeneity Extended reading list: Phys. Fluids B 3, 2822 (1991) PRL 78, 674 (1997) PoP 4, 3323 (1997) Nucl. Fusion 55, 033005 (2015) arXiv:1610.06016	PoP 19, 056103 (2012) ++extended reading list (look on the right)	Ian Abel (Chalmers) Felix Parra comes back from his sabbatical in Spain
VI	Thu Nov 17.	11:30 501 DWB	Plasma Seminar (organised by MICHAEL) Greg Hammett (Princeton) --- Full-f gyrokinetic simulations of the LAPD device with open field lines and sheath boundary conditions	arXiv:1610.09056	Greg Hammett (Princeton) Ian Abel (Chalmers)
VII	Thu Nov 24.	11:30 501 DWB	Plasma Group Meeting (organised by MICHAEL) Free discussion/research updates		Michael Fox (St Olave's)
VIII	Thu Dec 1.	11:30 Fisher Rm	Plasma Seminar (organised by MICHAEL) William Bethune (Grenoble) --- Non-ideal magnetohydrodynamics in protoplanetary disks	arXiv:1603.02475 +preprint from speaker on request	William Bethune (Grenoble)
9	Thu Dec 8	11:30 501 DWB	Plasma Seminar (organised by ALEX) Troy Carter (UCLA) --- Electromagnetic turbulence and transport in increased-beta LAPD plasmas	RSI 87, 025105 (2016) PoP 22, 062105 (2015) +2 preprints from speaker on request	Troy Carter (UCLA) Nuno Loureiro (MIT) Scott Melville (Imperial)
10	Thu Dec 15	11:30 501 DWB	Plasma Group Meeting (organised by ALEX) Updates from everyone		Antoine Bret (U. Castilla La Mancha)
	Thu Dec 22	No seminar. Merry Xmas!
	Thu Dec 29	No seminar. Happy NY!

Hilary Term of 2017