Publications


Flow damping in stellarators close to quasisymmetry

PLASMA PHYSICS AND CONTROLLED FUSION 57 (2015) ARTN 014014

I Calvo, FI Parra, J Luis Velasco, J Arturo Alonso


INEFFICIENT DRIVING OF BULK TURBULENCE BY ACTIVE GALACTIC NUCLEI IN A HYDRODYNAMIC MODEL OF THE INTRACLUSTER MEDIUM

ASTROPHYSICAL JOURNAL 815 (2015) ARTN 41

CS Reynolds, SA Balbus, AA Schekochihin


Exploring Mbar shock conditions and isochorically heated aluminum at the Matter in Extreme Conditions end station of the Linac Coherent Light Source (invited).

The Review of scientific instruments 85 (2014) 11E702-

LB Fletcher, HJ Lee, B Barbrel, M Gauthier, E Galtier, B Nagler, T Döppner, S LePape, T Ma, A Pak, D Turnbull, T White, G Gregori, M Wei, RW Falcone, P Heimann, U Zastrau, JB Hastings, SH Glenzer

Recent experiments performed at the Matter in Extreme Conditions end station of the Linac Coherent Light Source (LCLS) have demonstrated the first spectrally resolved measurements of plasmons from isochorically heated aluminum. The experiments have been performed using a seeded 8-keV x-ray laser beam as a pump and probe to both volumetrically heat and scatter x-rays from aluminum. Collective x-ray Thomson scattering spectra show a well-resolved plasmon feature that is down-shifted in energy by 19 eV. In addition, Mbar shock pressures from laser-compressed aluminum foils using velocity interferometer system for any reflector have been measured. The combination of experiments fully demonstrates the possibility to perform warm dense matter studies at the LCLS with unprecedented accuracy and precision.


Turbulent heating in galaxy clusters brightest in X-rays.

Nature 515 (2014) 85-87

I Zhuravleva, E Churazov, AA Schekochihin, SW Allen, P Arévalo, AC Fabian, WR Forman, JS Sanders, A Simionescu, R Sunyaev, A Vikhlinin, N Werner

The hot (10(7) to 10(8) kelvin), X-ray-emitting intracluster medium (ICM) is the dominant baryonic constituent of clusters of galaxies. In the cores of many clusters, radiative energy losses from the ICM occur on timescales much shorter than the age of the system. Unchecked, this cooling would lead to massive accumulations of cold gas and vigorous star formation, in contradiction to observations. Various sources of energy capable of compensating for these cooling losses have been proposed, the most promising being heating by the supermassive black holes in the central galaxies, through inflation of bubbles of relativistic plasma. Regardless of the original source of energy, the question of how this energy is transferred to the ICM remains open. Here we present a plausible solution to this question based on deep X-ray data and a new data analysis method that enable us to evaluate directly the ICM heating rate from the dissipation of turbulence. We find that turbulent heating is sufficient to offset radiative cooling and indeed appears to balance it locally at each radius-it may therefore be the key element in resolving the gas cooling problem in cluster cores and, more universally, in the atmospheres of X-ray-emitting, gas-rich systems on scales from galaxy clusters to groups and elliptical galaxies.


Electron-phonon equilibration in laser-heated gold films

PHYSICAL REVIEW B 90 (2014) ARTN 014305

TG White, P Mabey, DO Gericke, NJ Hartley, HW Doyle, D McGonegle, DS Rackstraw, A Higginbotham, G Gregori


FINGERPRINTS OF GALACTIC LOOP I ON THE COSMIC MICROWAVE BACKGROUND

ASTROPHYSICAL JOURNAL LETTERS 789 (2014) ARTN L29

H Liu, P Mertsch, S Sarkar


Erratum: IceCube sensitivity for low-energy neutrinos from nearby supernovae(Astronomy and Astrophysics (2011) 535 : A109 (DOI: 10.1051/0004-6361/201117810))

Astronomy and Astrophysics 563 (2014)

R Abbasi, Y Abdou, T Abu-Zayyad, M Ackermann, J Adams, JA Aguilar, M Ahlers, MM Allen, D Altmann, K Andeen, J Auffenberg, X Bai, M Baker, SW Barwick, V Baum, R Bay, JL Bazo Alba, K Beattie, JJ Beatty, S Bechet, JK Becker, KH Becker, ML Benabderrahmane, S BenZvi, J Berdermann, P Berghaus, D Berley, E Bernardini, D Bertrand, DZ Besson, D Bindig, M Bissok, E Blaufuss, J Blumenthal, DJ Boersma, C Bohm, D Bose, S Böser, O Botner, AM Brown, S Buitink, KS Caballero-Mora, M Carson, D Chirkin, B Christy, F Clevermann, S Cohen, C Colnard, DF Cowen, AH Cruz Silva, MV D'Agostino, M Danninger, J Daughhetee, JC Davis, C De Clercq, T Degner, L Demirörs, F Descamps, P Desiati, G De Vries-Uiterweerd, T Deyoung, JC Díaz-Vélez, M Dierckxsens, J Dreyer, JP Dumm, M Dunkman, J Eisch, RW Ellsworth, O Engdegård, S Euler, PA Evenson, O Fadiran, AR Fazely, A Fedynitch, J Feintzeig, T Feusels, K Filimonov, C Finley, T Fischer-Wasels, BD Fox, A Franckowiak, R Franke, TK Gaisser, J Gallagher, L Gerhardt, L Gladstone, T Glüsenkamp, A Goldschmidt, JA Goodman, D Góra, D Grant, T Griesel, A Groß, S Grullon


Producing bright X-rays for imaging applications using a laser wakefield accelerator

Optics InfoBase Conference Papers (2014)

SPD Mangles, MS Bloom, J Bryant, JM Cole, A Döpp, S Kneip, H Nakamura, K Poder, MJV Streeter, J Wood, Z Najmudin, R Bendoyro, J Jiang, NC Lopes, C Russo, O Cheklov, K Ertel, SJ Hawkes, CJ Hooker, D Neely, PA Norreys, PP Rajeev, DR Rusby, RHH Scott, DR Symes, J Holloway, M Wing, JF Seely

We report on the generation of bright multi-keV betatron X-ray radiation using a GeV laser wakefield accelerator and investigate the use of these X-rays for various imaging applications. © 2014 Optical Society of America.


Producing bright X-rays for imaging applications using a laser wakefield accelerator

Optics InfoBase Conference Papers (2014)

SPD Mangles, MS Bloom, J Bryant, JM Cole, A Döpp, S Kneip, H Nakamura, K Poder, MJV Streeter, J Wood, Z Najmudin, R Bendoyro, J Jiang, NC Lopes, C Russo, O Cheklov, O Ertel, S Hawkes, CJ Hooker, D Neely, PA Norreys, PP Rajeev, DR Rusby, RHH Scott, DR Symes, J Holloway, M Wing, JF Seely

We report on the generation of bright multi-keV betatron X-ray radiation using a GeV laser wakefield accelerator and investigate the use of these X-rays for various imaging applications. © 2014 Optical Society of America.


Do high-redshift quasars have powerful jets?

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 442 (2014) L81-L84

AC Fabian, SA Walker, A Celotti, G Ghisellini, P Mocz, KM Blundell, RG McMahon


Quantum radiation reaction in laser-electron-beam collisions.

Phys Rev Lett 112 (2014) 015001-

TG Blackburn, CP Ridgers, JG Kirk, AR Bell

It is possible using current high-intensity laser facilities to reach the quantum radiation reaction regime for energetic electrons. An experiment using a wakefield accelerator to drive GeV electrons into a counterpropagating laser pulse would demonstrate the increase in the yield of high-energy photons caused by the stochastic nature of quantum synchrotron emission: we show that a beam of 10(9) 1 GeV electrons colliding with a 30 fs laser pulse of intensity 10(22)  W cm(-2) will emit 6300 photons with energy greater than 700 MeV, 60× the number predicted by classical theory.


Equivalence of two independent calculations of the higher order guiding center Lagrangian

PHYSICS OF PLASMAS 21 (2014) ARTN 104506

FI Parra, I Calvo, JW Burby, J Squire, H Qin


Inboard and outboard radial electric field wells in the H- and I-mode pedestal of Alcator C-Mod and poloidal variations of impurity temperature

NUCLEAR FUSION 54 (2014) ARTN 083017

C Theiler, RM Churchill, B Lipschultz, M Landreman, DR Ernst, JW Hughes, PJ Catto, FI Parra, IH Hutchinson, ML Reinke, AE Hubbard, ES Marmar, JT Terry, JR Walk, AC-M Team


Equilibration dynamics and conductivity of warm dense hydrogen

PHYSICAL REVIEW E 90 (2014) ARTN 013104

U Zastrau, P Sperling, A Becker, T Bornath, R Bredow, T Doeppner, S Dziarzhytski, T Fennel, LB Fletcher, E Forster, C Fortmann, SH Glenzer, S Goede, G Gregori, M Harmand, V Hilbert, B Holst, T Laarmann, HJ Lee, T Ma, JP Mithen, R Mitzner, CD Murphy, M Nakatsutsumi, P Neumayer, A Przystawik, S Roling, M Schulz, B Siemer, S Skruszewicz, J Tiggesbaeumker, S Toleikis, T Tschentscher, T White, M Woestmann, H Zacharias, R Redmer


REVIEW OF PARTICLE PHYSICS Particle Data Group

CHINESE PHYSICS C 38 (2014) UNSP 090001

KA Olive, K Agashe, C Amsler, M Antonelli, J-F Arguin, DM Asner, H Baer, HR Band, RM Barnett, T Basaglia, CW Bauer, JJ Beatty, VI Belousov, J Beringer, G Bernardi, S Bethke, H Bichsel, O Biebel, E Blucher, S Blusk, G Brooijmans, O Buchmueller, V Burkert, MA Bychkov, RN Cahn, M Carena, A Ceccucci, A Cerri, D Chakraborty, M-C Chen, RS Chivukula, K Copic, G Cowan, O Dahl, G D'Ambrosio, T Damour, D de Florian, A de Gouvea, T DeGrand, P de Jong, G Dissertori, BA Dobrescu, M Doser, M Drees, HK Dreiner, DA Edwards, S Eidelman, J Erler, VV Ezhela, W Fetscher, BD Fields, B Foster, A Freitas, TK Gaisser, H Gallagher, L Garren, H-J Gerber, G Gerbier, T Gershon, T Gherghetta, S Golwala, M Goodman, C Grab, AV Gritsan, C Grojean, DE Groom, M Grunewald, A Gurtu, T Gutsche, HE Haber, K Hagiwara, C Hanhart, S Hashimoto, Y Hayato, KG Hayes, M Heffner, B Heltsley, JJ Hernandez-Rey, K Hikasa, A Hoecker, J Holder, A Holtkamp, J Huston, JD Jackson, KF Johnson, T Junk, M Kado, D Karlen, UF Katz, SR Klein, E Klempt, RV Kowalewski, F Krauss, M Kreps, B Krusche, YV Kuyanov, Y Kwon, O Lahav, J Laiho, P Langacker, A Liddle, Z Ligeti, C-J Lin, TM Liss, L Littenberg, KS Lugovsky, SB Lugovsky, F Maltoni, T Mannel, AV Manohar, WJ Marciano, AD Martin, A Masoni, J Matthews, D Milstead, P Molaro, K Moenig, F Moortgat, MJ Mortonson, H Murayama, K Nakamura, M Narain, P Nason, S Navas, M Neubert, P Nevski, Y Nir, L Pape, J Parsons, C Patrignani, JA Peacock, M Pennington, ST Petcov, A Piepke, A Pomarol, A Quadt, S Raby, J Rademacker, G Raffelt, BN Ratcliff, P Richardson, A Ringwald, S Roesler, S Rolli, A Romaniouk, LJ Rosenberg, JL Rosner, G Rybka, CT Achrajda, Y Sakai, GP Salam, S Sarkar, F Sauli, O Schneider, K Scholberg, D Scott, V Sharma, SR Sharpe, M Silari, T Sjostrand, P Skands, JG Smith, GF Smoot, S Spanier, H Spieler, C Spiering, A Stah, T Stanev, SL Stone, T Sumiyoshi, MJ Sphers, F Takahashi, M Tanabashi, J Terning, L Tiator, M Titov, NP Tkachenko, NA Tornqvist, D Tovey, G Valencia, G Venanzoni, MG Vincter, P Vogel, A Vogt, SP Wakely, W Walkowiak, CW Walter, DR Ward, G Weiglein, DH Weinberg, EJ Weinberg, M White, LR Wiencke, CC Woh, L Wofenstein, J Womersley, CL Woody, RL Workman, A Yamamoto, W-M Yao, GP Zeller, OV Zenin, J Zhang, R-Y Zhu, F Zimmermann, PA Zyla, G Harper, VS Lugovsky, P Schaffner, PD Grp


From cosmic ray source to the galactic pool

Monthly Notices of the Royal Astronomical Society 437 (2014) 2802-2805

KM Schure, AR Bell

The Galactic cosmic ray spectrum is a remarkably straight power law. Our current understanding is that the dominant sources that accelerate cosmic rays up to the knee (3 × 1015 eV) or perhaps even the ankle (3 × 1018 eV), are young Galactic supernova remnants. In theory, however, there are various reasons why the spectrum may be different for different sources, and may not even be a power law if non-linear shock acceleration applies during the most efficient stages of acceleration.We show how the spectrum at the accelerator translates to the spectrum that makes up the escaping cosmic rays that replenish the Galactic pool of cosmic rays. We assume that cosmic ray confinement, and thus escape, is linked to the level of magnetic field amplification, and that the magnetic field is amplified by streaming cosmic rays according to the non-resonant hybrid or resonant instability. When a fixed fraction of the energy is transferred to cosmic rays, it turns out that a source spectrum that is flatter than E-2 will result in an E-2 escape spectrum, whereas a steeper source spectrum will result in an escape spectrum with equal steepening. This alleviates some of the concern that may arise from expected flat or concave cosmic ray spectra associated with non-linear shock modification. © 2013 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.


Laminar shocks in high power laser plasma interactions

Physics of Plasmas 21 (2014)

RA Cairns, R Bingham, P Norreys, R Trines

We propose a theory to describe laminar ion sound structures in a collisionless plasma. Reflection of a small fraction of the upstream ions converts the well known ion acoustic soliton into a structure with a steep potential gradient upstream and with downstream oscillations. The theory provides a simple interpretation of results dating back more than forty years but, more importantly, is shown to provide an explanation for recent observations on laser produced plasmas relevant to inertial fusion and to ion acceleration. © 2014 AIP Publishing LLC.


The effect of diamagnetic flows on turbulent driven ion toroidal rotation

PHYSICS OF PLASMAS 21 (2014) ARTN 056106

JP Lee, M Barnes, FI Parra, EA Belli, J Candy


THE RELATION BETWEEN GAS DENSITY AND VELOCITY POWER SPECTRA IN GALAXY CLUSTERS: QUALITATIVE TREATMENT AND COSMOLOGICAL SIMULATIONS

ASTROPHYSICAL JOURNAL LETTERS 788 (2014) ARTN L13

I Zhuravleva, EM Churazov, AA Schekochihin, ET Lau, D Nagai, M Gaspari, SW Allen, K Nelson, IJ Parrish


Reduction of core turbulence in I-mode plasmas in Alcator C-Mod

NUCLEAR FUSION 54 (2014) ARTN 083019

AE White, M Barnes, A Dominguez, M Greenwald, NT Howard, AE Hubbard, JW Hughes, DR Mikkelsen, FI Parra, ML Reinke, C Sung, J Walk, DG Whyte