OXFORD PLASMA THEORY GROUP

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. "Plasma group meetings" 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. The seminars and group meetings are organised by Michael Barnes, Felix Parra and Alex Schekochihin, please contact them with any queries or if you wish to present something.

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/MT 2016; HT 2017; TT & Summer 2017; Autumn/MT 2017; HT 2018; TT & Summer 2018; MT 2018; HT 2019; TT & Summer 2019; MT 2019;

  Hilary Term of 2020

The seminars/group meetings will be on Thursday at 11:00 in 501 Denys Wilkinson Building, except where indicated otherwise below.
Note also the ALP Seminars (here is a list of all Physics seminars)

If you know exactly what you are going to do, what is the point of doing it? Pablo Picasso
He goeth furthest who knows not whither he is going. Oliver Cromwell

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! Alex Schekochihin
It's not the triviality, it's the emptiness of it that bothers me. Bryan Taylor
Never take 0 for an answer. Alex Schekochihin
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
What is the point? 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
It is better to be vaguely right than exactly wrong. Carveth Read (usually attributed to Maynard Keynes)


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 & Steve Cowley (in conversation)
I don't give a damn about astrophysics, explain to me what is going on. Anatoly Spitkovsky
Have you subtracted the baby with the bathwater? Steve Balbus
 
This is not rigour, unless you mean rigor mortis. Ian Abel
I wouldn't say these are theoretical arguments... Let's just call them arguments. François Rincon
You can never be too happy with the state of your closure. Amitava Bhattacharjee
For this plot, 1 is 6.--- Weeell, not even. Steve Cowley & Steve Balbus
This qualitative explanation is not of sufficient quality. Eugene Churazov
If you mean it seriously, this is actually a very good question. Minhyong Kim
This paper is a tour de farce. Ian Abel
What is modelling? You run a simulation, you compare. If it coincides, great! If it doesn't coincide, fuck! Felix Parra
We are stuck at x=0. Felix Parra
I have seen papers where the student wasn't the problem. Michael Hardman
There has been a lot of fascinating work on this subject, most of it kind of boring. Philipp Kempski
So now you want us to drop everything we are doing and start worrying about what the big questions are?! Ian Abel
Oh dear, I thought I had some conclusions. Nuno Loureiro
I've got my little fingers inside this plasma. Steve Cowley
Words will play a big role in this talk. Dmitri Uzdensky
Everything that can be done should be done---and that's the astrophysical attitude. Michael Medvedev
What I will talk about is not low-hanging fruit. A lot of people have looked at this. There is no fruit here at all.---How about sour grapes? Michael Medvedev & Nuno Loureiro
In order to have a disappointment, you first have to have an appointment. Alex Schekochihin
[these quotes are mostly from Oxford plasma seminars and the Vienna meetings]

Wk Date
Time
& place
Speaker & Topic
Background reading
Comings and goings
(incl. visitors in town)

Thu
Jan
2
No seminar

-1
Thu
Jan
9
11:00
501
DWB
Plasma Journal Club (organised by MICHAEL & JASON)
Boozer's white paper "Stellarators as a fast path to fusion energy", arXiv:1912.06289


0
Thu
Jan
16
11:00
501
DWB
Plasma Group Meeting (organised by ALEX)
Juan Ruiz Ruiz, Ollie Beeke, Valerian Chen, Nick Christen, Michael Hardman, Plamen Ivanov, Jason Parisi (Oxford) --- Possible plans for joint projects


I
Thu
Jan
23,
11:00
501
DWB
Plasma Group Meeting (organised by ALEX)
Denis St-Onge --- Update on global-local schemes

Justin Ball
(EPFL)
Fri
Jan
24
11:00
501
DWB
Plasma Group Meeting (organised by FELIX)
Justin Ball (EPFL) --- Gyrokinetic simulations a bit further out
PoP 8, 447 (2001)
arXiv:1912.09193
II
Thu
Jan
30,
11:00
501
DWB
Plasma Group Meeting (organised by FELIX)
TBA


III
Thu
Feb
6
11:00
501
DWB
Plasma Group Meeting (organised by MICHAEL)
Ollie Beeke --- Attempting to recreate an internal transport barrier (ITB) with the local gyrokinetic code GS2


IV
Thu
Feb
13'
11:00
501
DWB
Plasma Seminar (organised by ALEX)
Giannandrea Inchingolo (Bologna) --- Kinetic-scale effects in collisionless magnetorotational instability
The magnetorotational instability (MRI) is a crucial mechanism of angular momentum transport in several astrophysical scenarios, like accretion disks around black holes. The MRI has been widely studied using MHD models and simulations, to understand the behavior of astrophysical fluids in a state of differential rotation. In particular, the MRI plays a crucial role in the transport of angular momentum and turbulence generation in the late nonlinear evolution of the system. In radiatively inefficient accretion flow (RIAF) models for accretion onto compact objects, the accretion proceeds via a hot, low-density plasma with the proton temperature larger than the electron temperature. To maintain the two-temperature flow characteristic of RIAF models, the typical collision rate must be much smaller than the accretion rate. This suggests that the standard MHD approach may be insufficient, and a kinetic description is required instead. Leveraging on our recent implementation of the shearing co-rotating framework in OSIRIS 4.0, we present our recent studies on collisionless MRI in high-beta plasma. On sufficient large simulation domains, we observe the development of an MRI-induced not-relativistic turbulent regime during the late nonlinear stage of the evolution. Increasing the mass ratio of our simulations, we show the development of enhanced ion heating during the early nonlinear phase of collisionless MRI (channel flows regime). We will explore the mechanism responsible for these effects. The development of a drift-kink instability on large domains, combined with the magnetic reconnection, is responsible for the generation of the turbulent regime observed. The rise of an electric field during the early nonlinear regime of the MRI acts differently on the two plasma species, inducing the temperature difference observed in our study. We support our assumptions with a theoretical model for kinetic compression of current sheets, giving a quantitative prediction on the trapped particle acceleration during the compression phase.
ApJ 859, 149 (2018)
Giannandrea Inchingolo
(Bologna)
V
Thu
Feb
20,'
11:00
501
DWB
Plasma Group Meeting (organised by ALEX)
TBA

Steve Cowley
(Princeton)
VI
Thu
Feb
27,
11:00
501
DWB
Plasma Seminar (organised by FELIX)
Peter Catto (MIT) --- Quasilinear theory: What does the delta function mean?

Peter Catto (MIT)
VII
Thu
Mar
5
11:00
501
DWB
Plasma Group Meeting (organised by MICHAEL)
Nicolas Christen --- TBA

Peter Catto (MIT)
VIII
Thu
Mar
12
11:00
501
DWB
Plasma Group Meeting (organised by ALEX)
Toby Adkins --- TBC
transfer report
on request
from Toby

9
Thu
Mar
19.
11:00
501
DWB
Plasma Group Meeting (organised by FELIX)
TBA


10
Thu
Mar
26.
11:00
501
DWB
Plasma Group Meeting (organised by MICHAEL)
Alex von Boetticher --- TBA



Thu
Apr
2.
11:00
501
DWB
Plasma Group Meeting (organised by FELIX)
TBA



Thu
Apr
9.,'
No seminar

-1
Thu
Apr
16'
11:00
501
DWB
Plasma Group Meeting (organised by MICHAEL)
TBA


0
Thu
Apr
23.
11:00
501
DWB
Plasma Group Meeting (organised by FELIX)
TBA


I
Thu
Apr
30
11:00
501
DWB
Plasma Seminar (organised by ALEX)
Lev Arzamasskiy (Princeton) --- TBA

Lev Arzamasskiy,
Matt Kunz
(Princeton)