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 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 |
It is
better to be roughly right than precisely wrong. Maynard
Keynes 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 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 and Steve Balbus Это качественное объяснение недостаточно качественное. Eugene Churazov If you mean it seriously, this is actually a very good question. Minhyong Kim |
Wk | Date |
Time
& place |
Speaker & Topic |
Background reading |
Comings and goings (incl. visitors in town) |
Thu Sept 7 |
11:30 501 DWB |
Plasma
Group Meeting (organised
by MICHAEL) Yohei Kawazura --- Update on the i-e heating problem in (hybrid) GK |
|||
Thu Sept 14 |
11:30 501 DWB |
Plasma
Group Meeting (organised
by ALEX) Francois Rincon (Toulouse) --- Coherent structures and how to find them (informal tutorial) |
JFM 731, 1 (2013) A&A 575, A14 (2015) A&A 598, A87 (2017) |
Matt Kunz (Princeton) Francois Rincon (Toulouse) |
|
Thu Sept 21. |
11:30 501 DWB |
Plasma
Seminar (organised
by FELIX) Brian Applebe (Imperial) --- The challenge of measuring ion temperature in Inertial Confinement Fusion |
Nature
Phys. 12, 435 (2016) PoP 21, 072701 (2014) |
||
-1 |
Thu Sept 28. |
No seminar
|
|||
0 |
Thu Oct 5 |
11:30 501 DWB |
Plasma
Group Meeting (organised
by ALEX) 1) Steve Balbus --- General relativistic thin disc evolution 2) Yohei Kawazura --- Proposal: a kinetic study of extraction of a black hole's rotational energy in spacetime shearing box |
1) MNRAS 471, 4832 (2017) 2) Ask Yohei for a short write up & refrence list |
Mantas
Abazorius & Oliver Beeke join the group as DPhil students to work with F. Parra & M. Barnes, respectively |
I |
Thu Oct 12 |
11:30 501 DWB |
Plasma
Group Meeting (organised
by ALEX) Alex Schekochihin --- A tutorial on nonlinear plasma stability, free energy, available energy and all that |
KT lecture notes, sec 5.2 JPP 83, 715830401 (2017) Fowler's review |
Toby Adkins rejoins the group as MMathPhys student to work with A. Schekochihin |
II |
Thu Oct 19 |
11:30 501 DWB |
Plasma Seminar (organised
by ALEX) Daniel Verscharen (UCL) --- Fluctuations in the collisionless solar wind: MHD or kinetic? The fast
solar wind is a collisionless magnetised plasma. Therefore, deviations
from thermodynamic equilibrium can develop, and a kinetic description
of the plasma becomes necessary. I will discuss the properties of the
dispersion relations and polarisation properties of kinetic slow modes
and magnetohydrodynamic slow modes. I compare theoretical predictions
for the fluctuations in the three lowest velocity moments (density,
bulk velocity, and pressure) of the proton distribution function
associated with large-scale compressive slow modes to solar-wind
observations at 1 au. Surprisingly, the predictions from
magnetohydrodynamics (MHD) are in a better agreement with the data than
the kinetic predictions, even at times when the collisionality of the
plasma is low. This unexpected result suggests that some unknown
kinetic process assumes the role of collisions in suppressing
fluctuations in heat flux. Possible candidates for such a process
include fluctuating-moment effects, wave-particle scattering on
small-scale fluctuations, and anti-phase-mixing.
|
ApJ 840, 106 (2017) |
Daniel Verscharen (UCL) |
III |
Thu Oct 26 |
11:30 501 DWB |
Plasma
Group Meeting (organised
by ALEX) Nicolas Christen --- Reconstruction of turbulence-driven core rotation profiles in tokamaks (transfer exam presentation, examiners F. Parra & A. Schekochihin) |
NF 51, 094027 (2011) PRL 106, 175004 (2011) arXiv:1207.4419 PoP 2, 2687 (1995) transfer report: ask author |
|
Fri Oct 27 |
14:00 D. Sciama LT |
Theoretical Physics Colloquium Felix Parra (Oxford) --- Magnetized particle motion in 3D magnetic fields and its effect on fusion energy |
|||
IV |
Thu Nov 2 |
11:30 501 DWB |
Plasma
Group Meeting (organised
by FELIX) Jason Parisi --- The effect of sheared flows on ITG-driven turbulence far above marginality (transfer exam presentation, examiners S. Cowley & A. Schekochihin) |
PPCF 52, 125001 (2010) PPCF 54 055011 (2012) transfer report: ask author |
Ivan Calvo (CIEMAT) |
V |
Thu Nov 9 |
11:30 501 DWB |
Plasma Seminar (organised
by ALEX) Chris Pringle (Coventry) --- Transitions in subcritical plasmas with sheared flow |
arXiv:1708.03565 |
Ivan Calvo (CIEMAT) Chris Pringle (Coventry) |
VI |
Thu Nov 16. |
11:30 501 DWB |
Plasma
Group Meeting (organised
by FELIX) George Wilkie (Chalmers) --- Basic physics and kinetic simulation of runaway electrons |
Adam Stahl's PhD thesis |
George Wilkie (Chalmers) |
VII |
Thu Nov 23. |
11:30 501 DWB |
Plasma
Group Meeting (organised
by MICHAEL) Bill Dorland (Maryland) --- Discussion on various GK issues |
arXiv:1708.04029 arXiv:1705.05407 arXiv:1703.06129 |
Bill
Dorland (Maryland) |
VIII |
Thu Nov 30. |
11:30 501 DWB |
Plasma
Group Meeting (organised
by FELIX) Valerian Chen --- Effects of misaligning the probe beam and magnetic field in Doppler backscattering measurements (transfer exam presentation, examiners M. Barnes & Colin Roach) |
NF 55, 073024 (2015) PPCF 44, 467 (2002) PoP 5, 3529 (1998) transfer report: ask author |
|
9 |
Thu Dec 7 |
11:30 501 DWB |
Plasma
Group Meeting (organised
by ALEX) Plamen Ivanov --- Zonal flow-drift wave interactions in ion-scale turbulence in differentially rotating tokamak plasmas: BES measurements and gyrokinetic models (transfer exam presentation, examiners P. Dellar & F. Parra) |
PRL 85, 5336 (2000) JPP 83, 905830504 (2017) transfer report: ask author |
|
10 |
Thu Dec 14 |
11:30 501 DWB |
Plasma
Group Meeting (organised
by ALEX) Yohei Kawazura --- Ion vs. electron heating in GK turbulence |
ApJ 651, 590 (2006) ApJS 182, 310 (2009) arXiv:1708.07235 |
|
Thu Dec 21 |
No seminar |
Ian Abel (Chalmers) Adnane Osmane (Aalto U, Finland) joins the group as visiting postdoctoral fellow |
|||
Thu Dec 28 |
No seminar. Happy New Year! |