Dr Christopher Chen

Dr Christopher Chen

Lecturer in Space Plasma Physics
Address:
School of Physics and Astronomy
Queen Mary, University of London
327 Mile End Road, London, E1 4NS

Telephone: 0207 882 7025
Room: GO Jones 513
Email:

Research Interests

I am a Proleptic Lecturer and STFC Ernest Rutherford Fellow in the Astronomy Unit. My research area is space plasma physics, in particular the solar wind and the variety of processes that occur within it. The solar wind is created as material from the Sun is continually propelled into interplanetary space - this material is so hot that the majority of its particles are ionised, forming a plasma that displays a rich variety of complex behaviour.

The solar wind is one of the best places to study fundamental plasma physics. Throughout the solar wind, there are many spacecraft making detailed in situ measurements of its properties, such as the electromagnetic fields it contains and the distributions of the different particle species. My research involves the analysis of this data, along with theoretical and computational models, to understand its behaviour and address some of the outstanding problems in plasma astrophysics.

In particular, I am interested in solar wind turbulence. The solar wind does not flow smoothly, but displays complex chaotic behaviour over a large range of scales. This turbulence is not well understood, and is particularly interesting because it involves the chaotic interaction between the electromagnetic fields and vast numbers of charged particles, touching on fundamental questions in non-equilibrium statistical mechanics. As well as being a topic of fundamental interest, plasma turbulence is thought to play an important role in many areas of modern astrophysics. For example, it is thought to be involved in heating the solar corona to several hundred times the temperature of the Sun's surface, determining the propagation of energetic particles such as cosmic rays, enabling the formation of accretion disks through angular momentum transport, and generating the large-scale magnetic fields we see in the universe.

I am involved in several currently operating, upcoming, and proposed space missions. For example:

  • Parker Solar Probe (PSP): I am a member of FIELDS team, which has developed a suite of instruments for the upcoming NASA Parker Solar Probe mission. This spacecraft will launch in Summer 2018 and travel to within 9 solar radii from the Sun's surface - the first spacecraft to fly through the solar corona - to directly sample the solar wind at its birth. With this data, we will be able to investigate the role played by turbulence and other processes in the heating of the corona and generation of the solar wind.
  • Turbulence Heating Observer (THOR): THOR is a proposed ESA mission to study turbulent heating and plasma energisation in a variety of space environments, and its implications for our understanding of astrophysical plasmas. I am a member of the THOR Science Study Team and a Co-I for the THOR magnetometer.
  • Magnetospheric Multiscale (MMS): MMS is a group of four closely-spaced spacecraft to study magnetic reconnection in and around the Earth's magnetosphere. I am a member of the MMS Science Working Team.

A list of my publications can be found here.

Opportunities

If you are interested in working with me as part of the space plasma group, the following opportunities are available:

  • PhD studentships: see the PhD Projects tab above for the current projects I have available, and see here for more information about the application process; please contact me if you are interested.
  • Postdoc positions: I will advertise these here as they become available, but feel free to contact me at any time if you are interested.
  • Fellowships: see here for information about applying for a fellowship in the Astronomy Unit and feel free to contact me if you are considering applying.
  • Internships: available to undergraduate students, typically for a period of a few months over the summer (but other times can be considered); please contact me (ideally including your CV) for more information.

 

This is not an exhaustive list and I would be happy to discuss other project possibilities.

 

2017

Nature of Kinetic Scale Turbulence in the Earth's Magnetosheath
Chen CHK, Boldyrev S
Astrophysical Journal, Volume 842, page 122, 20th June 2017.
DOI: 10.3847/1538-4357/aa74e0

On Kinetic Slow Modes, Fluid Slow Modes, and Pressure-Balanced Structures in the Solar Wind
Verscharen D, Chen CHK, Wicks RT
Astrophysical Journal, Volume 840, page 106, 12th May 2017.
DOI: 10.3847/1538-4357/aa6a56

Electric and Magnetic Spectra from MHD to Electron Scales in the Magnetosheath
Matteini L, Alexandrova O, Chen CHK et al.
Monthly Notices of the Royal Astronomical Society, Volume 466, page 945, 1st April 2017.
DOI: 10.1093/mnras/stw3163

Multifractal Analysis of High Resolution Solar Wind Proton Density Measurements
Sorriso-Valvo L, Carbone F, Leonardis E et al.
Advances in Space Research, Volume 59, page 1642, 15th March 2017.
DOI: 10.1016/j.asr.2016.12.024

2016

Recent Progress in Astrophysical Plasma Turbulence from Solar Wind Observations
Chen CHK
Journal of Plasma Physics, Volume 82, page 535820602, 1st December 2016.
DOI: 10.1017/S0022377816001124

The FIELDS Instrument Suite for Solar Probe Plus: Measuring the Coronal Plasma and Magnetic Field, Plasma Waves and Turbulence, and Radio Signatures of Solar Transients
Bale SD, Goetz K, Harvey PR et al.
Space Science Reviews, Volume 204, page 49, 1st December 2016.
DOI: 10.1007/s11214-016-0244-5

Testing the Effects of Expansion on Solar Wind Turbulence
Vech D, Chen CHK
Astrophysical Journal Letters, Volume 832, page L16, 20th November 2016.
DOI: 10.3847/2041-8205/832/1/L16

Saturn's Quasiperiodic Magnetohydrodynamic Waves
Yates JN, Southwood DJ, Dougherty MK et al.
Geophysical Research Letters, Volume 43, page 11102, 16th November 2016.
DOI: 10.1002/2016GL071069

Turbulence Heating Observer - Satellite Mission Proposal
Vaivads A, Retino A, Soucek J et al.
Journal of Plasma Physics, Volume 82, page 905820501, 1st October 2016.
DOI: 10.1017/S0022377816000775

Experimental Determination of Whistler Wave Dispersion Relation in the Solar Wind
Stansby D, Horbury TS, Chen CHK et al.
Astrophysical Journal Letters, Volume 829, page L16, 20th September 2016.
DOI: 10.3847/2041-8205/829/1/L16

Multi-Species Measurements of the Firehose and Mirror Instability Thresholds in the Solar Wind
Chen CHK, Matteini L, Schekochihin AA et al.
Astrophysical Journal Letters, Volume 825, page L26, 10th July 2016.
DOI: 10.3847/2041-8205/825/2/L26

Power Spectral Density of Fluctuations of Bulk and Thermal Speeds in the Solar Wind
Šafránková J, Nemecek Z, Nemec F et al.
Astrophysical Journal, Volume 825, page 121, 10th July 2016.
DOI: 10.3847/0004-637X/825/2/121

Measures of Three-Dimensional Anisotropy and Intermittency in Strong Alfvénic Turbulence
Mallet A, Schekochihin AA, Chandran BDG et al.
Monthly Notices of the Royal Astronomical Society, Volume 459, page 2130, 21st June 2016.
DOI: 10.1093/mnras/stw802

Intermittency of Energy Dissipation in Alfvénic Turbulence
Zhdankin V, Boldyrev S, Chen CHK
Monthly Notices of the Royal Astronomical Society: Letters, Volume 457, page L69, 21st March 2016.
DOI: 10.1093/mnrasl/slv208

Density Fluctuations Upstream and Downstream of Interplanetary Shocks
Pit¿a A, Šafránková J, N¿me¿ek Z et al.
Astrophysical Journal, Volume 819, page 41, 1st March 2016.
DOI: 10.3847/0004-637X/819/1/41

Spectral Anisotropy of Elsässer Variables in Two-Dimensional Wave-Vector Space as Observed in the Fast Solar Wind Turbulence
Yan L, He J, Zhang L et al.
Astrophysical Journal Letters, Volume 816, page L24, 10th January 2016.
DOI: 10.3847/2041-8205/816/2/L24

2015

Proton Heating in Solar Wind Compressible Turbulence with Collisions between Counter-Propagating Waves
He J, Tu C, Marsch E et al.
Astrophysical Journal Letters, Volume 813, page L30, 10th November 2015.
DOI: 10.1088/2041-8205/813/2/L30

Magnetic Field Rotations in the Solar Wind at Kinetic Scales
Chen CHK, Matteini L, Burgess D et al.
Monthly Notices of the Royal Astronomical Society: Letters, Volume 453, page L64, 11th October 2015.
DOI: 10.1093/mnrasl/slv107

Spectral Breaks of Alfvenic Turbulence in a Collisionless Plasma
Boldyrev S, Chen CHK, Xia Q et al.
Astrophysical Journal, Volume 806, page 238, 20th June 2015.
DOI: 10.1088/0004-637X/806/2/238

Effects of Electron Drifts on the Collisionless Damping of Kinetic Alfvén Waves in the Solar Wind
Tong Y, Bale SD, Chen CHK et al.
Astrophysical Journal Letters, Volume 804, page L36, 10th May 2015.
DOI: 10.1088/2041-8205/804/2/L36

Solar wind density spectra around the ion spectral break
Šafránková J, N¿me¿ek Z, N¿mec F et al.
Astrophysical Journal, Volume 803, issue 2, 20th April 2015.
DOI: 10.1088/0004-637X/803/2/107

Inertial-range kinetic turbulence in pressure-anisotropic astrophysical plasmas
Kunz MW, Schekochihin AA, Chen CHK et al.
Journal of Plasma Physics, Volume 81, issue 5, 1st January 2015.
DOI: 10.1017/S0022377815000811

2014

Ion-scale spectral break of solar wind turbulence at high and low beta
Chen CHK, Leung L, Boldyrev S et al.
Geophysical Research Letters, Volume 41, issue 22, page 8081, 28th November 2014.
DOI: 10.1002/2014GL062009

Intermittency of solar wind density fluctuations from ion to electron scales
Chen CHK, Sorriso-Valvo L, Šafránková J et al.
Astrophysical Journal Letters, Volume 789, issue 1, 1st July 2014.
DOI: 10.1088/2041-8205/789/1/L8

2013

Correlations at large scales and the onset of turbulence in the fast solar WIND
Wicks RT, Roberts DA, Mallet A et al.
Astrophysical Journal, Volume 778, issue 2, 1st December 2013.
DOI: 10.1088/0004-637X/778/2/177

Solar wind turbulence and the role of ion instabilities
Alexandrova O, Chen CHK, Sorriso-Valvo L et al.
Space Science Reviews, Volume 178, issue 2-4, page 101, 1st October 2013.
DOI: 10.1007/s11214-013-0004-8

Kinetic scale density fluctuations in the solar wind
Chen CHK, Howes GG, Bonnell JW et al.
AIP Conference Proceedings, Volume 1539, page 143, 1st August 2013.
DOI: 10.1063/1.4811008

Residual energy spectrum of solar wind turbulence
Chen CHK, Bale SD, Salem CS et al.
Astrophysical Journal, Volume 770, issue 2, 20th June 2013.
DOI: 10.1088/0004-637X/770/2/125

Electron heat conduction in the solar wind: Transition from spitzer-härm to the collisionless limit
Bale SD, Pulupa M, Salem C et al.
Astrophysical Journal Letters, Volume 769, issue 2, 1st June 2013.
DOI: 10.1088/2041-8205/769/2/L22

Nature of subproton scale turbulence in the solar wind.
Chen CHK, Boldyrev S, Xia Q et al.
Phys Rev Lett, Volume 110, issue 22, page 225002, 31st May 2013.
DOI: 10.1103/PhysRevLett.110.225002

Parallel electric field spectrum of solar wind turbulence
Mozer FS, Chen CHK
Astrophysical Journal Letters, Volume 768, issue 1, 1st May 2013.
DOI: 10.1088/2041-8205/768/1/L10

Alignment and scaling of large-scale fluctuations in the solar wind
Wicks RT, Mallet A, Horbury TS et al.
Physical Review Letters, Volume 110, issue 2, 11th January 2013.
DOI: 10.1103/PhysRevLett.110.025003

2012

Anisotropy in space plasma turbulence: Solar wind observations
Horbury TS, Wicks RT, Chen CHK
Space Science Reviews, Volume 172, issue 1-4, page 325, 1st November 2012.
DOI: 10.1007/s11214-011-9821-9

Three-dimensional structure of solar wind turbulence
Chen CHK, Mallet A, Schekochihin AA et al.
Astrophysical Journal, Volume 758, issue 2, 20th October 2012.
DOI: 10.1088/0004-637X/758/2/120

Using synthetic spacecraft data to interpret compressible fluctuations in solar wind turbulence
Klein KG, Howes GG, Tenbarge JM et al.
Astrophysical Journal, Volume 755, issue 2, 20th August 2012.
DOI: 10.1088/0004-637X/755/2/159

Density fluctuation spectrum of solar wind turbulence between ion and electron scales.
Chen CHK, Salem CS, Bonnell JW et al.
Phys Rev Lett, Volume 109, issue 3, page 035001, 20th July 2012.
DOI: 10.1103/PhysRevLett.109.035001

The slow-mode nature of compressible wave power in solar wind turbulence
Howes GG, Bale SD, Klein KG et al.
Astrophysical Journal Letters, Volume 753, issue 1, 1st July 2012.
DOI: 10.1088/2041-8205/753/1/L19

Identification of kinetic alfvén wave turbulence in the solar wind
Salem CS, Howes GG, Sundkvist D et al.
Astrophysical Journal Letters, Volume 745, issue 1, 20th January 2012.
DOI: 10.1088/2041-8205/745/1/L9

2011

Frame dependence of the electric field spectrum of solar wind turbulence
Chen CHK, Bale SD, Salem C et al.
Astrophysical Journal Letters, Volume 737, issue 2, 20th August 2011.
DOI: 10.1088/2041-8205/737/2/L41

Anisotropy of Alfvénic turbulence in the solar wind and numerical simulations
Chen CHK, Mallet A, Yousef TA et al.
Monthly Notices of the Royal Astronomical Society, Volume 415, issue 4, page 3219, 1st August 2011.
DOI: 10.1111/j.1365-2966.2011.18933.x

Anisotropy of imbalanced Alfvénic turbulence in fast solar wind
Wicks RT, Horbury TS, Chen CHK et al.
Physical Review Letters, Volume 106, issue 4, 24th January 2011.
DOI: 10.1103/PhysRevLett.106.045001

2010

Power and spectral index anisotropy of the entire inertial range of turbulence in the fast solar wind
Wicks RT, Horbury TS, Chen CHK et al.
Monthly Notices of the Royal Astronomical Society: Letters, Volume 407, issue 1, 1st September 2010.
DOI: 10.1111/j.1745-3933.2010.00898.x

Anisotropy of solar wind turbulence between ion and electron scales.
Chen CHK, Horbury TS, Schekochihin AA et al.
Phys Rev Lett, Volume 104, issue 25, page 255002, 25th June 2010.
DOI: 10.1103/PhysRevLett.104.255002

Interpreting power anisotropy measurements in plasma turbulence
Chen CHK, Wicks RT, Horbury TS et al.
Astrophysical Journal Letters, Volume 711, issue 2 PART 2, 1st January 2010.
DOI: 10.1088/2041-8205/711/2/L79