Accessibility statement

Plasma Diagnostics

‌We apply and continuously develop advanced plasma diagnostic techniques for accurate measurements of plasma parameters. Our diagnostics are largely based on active and passive optical techniques exploiting atomic and molecular principles, including non-linear laser spectroscopy and spectrally resolved nanosecond imaging. Some of the techniques we employ include phase resolved optical emission spectroscopy (PROES), one- and two- photon laser induced fluoresence (LIF), VUV UV VIS and IR absorption spectroscopy.

PhD position available.

Selected literature:

Absolute ozone densities in a radio-frequency driven atmospheric pressure plasma using two-beam UV-LED absorption spectroscopy and numerical simulations
A. Wijaikhum, D. Schröder, S. Schröter, A. R. Gibson, K. Niemi, J. Friderich, A. Greb, V. Schulz-von der Gathen, D. O'Connell, T. Gans
Plasma Sources Sci. Technol. 26 115004 (2017)

Controlled production of atomic oxygen and nitrogen in a pulsed radio-frequency atmospheric-pressure plasma
J. P. Dedrick, S. Schröter, K. Niemi, A. Wijaikhum, E. Wagenaars, N. de Oliveira, L. Nahon, J-P. Booth, D. O'Connell, T. Gans
J. Phys. D: Appl. Phys. 50 455204 (2017)

Energy resolved actinometry for simultaneous measurement of atomic oxygen densities and local mean electron energies in radio-frequency driven plasmas
Arthur Greb, Kari Niemie, Deborah O'Connell, Timo Gans
Appl. Phys. Lett., 105, 234105 (2014)

Phase Resolved Imaging of a Repetitive Extrusion of Hydrogen Plasma From a Hollow Cathode Source
S. Dixon, J. Dedrick, C. Charles, T. Gans,D. O'Connell, R. Boswell
Special Issue on Images in Plasma Science, IEEE Trans. Plasma Sci., 42, 10 2834 (2014)

Absolute atomic oxygen and nitrogen densities in radio-frequency driven atmospheric pressure cold plasmas: Synchrotron vacuum ultra-violet high-resolution Fourier-transform absorption measurements
K Niemi, D O’Connell, N de Oliveira, D Joyeux, L Nahon, J-P Booth, T Gans
Appl. Phys. Lett. 3 103 034102 (2013)

Formation of spatially periodic fronts of high-energy electrons in a radio-frequency driven surface microdischarge
J Dedrick, D O'Connell, T Gans, R.W Boswell, C Charles
Applied Physics Letters, vol 102, no. 3, ARTN 034109 (2013)

Nanosecond optical imaging spectroscopy of an electrothermal radiofrequency plasma thruster plume
C Charles, J Dedrick, R Boswell, D O'Connell, T Gans
Applied Physics Letters, vol 103, no. 12, 124103 (2013)

Two-photon absorption laser-induced fluorescence measurements of atomic nitrogen in a radio-frequency atmospheric-pressure plasma jet
E Wagenaars, T Gans, D O'Connell and K Niemi
Plasma Sources Sci. Technol. 21 042002 (2012)

Cold atmospheric pressure plasma jets as sources of singlet delta oxygen for biomedical applications
J.S Sousa, K Niemi, L.J Cox, Q.T Algwari, T Gans & D O'Connell
Journal of Applied Physics, vol 109, no. 12, 123302 (2011)

Electron dynamics and plasma jet formation in a helium atmospheric pressure dielectric barrier discharge jet
Q.T Algwari & D O'Connell
Applied Physics Letters, vol 99, no. 12, 121501, pp. 1-3 (2011)

Energetic electron avalanches and mode transitions in planar inductively coupled radio-frequency driven plasmas operated in oxygen

M Zaka-ul-Islam, K Niemi, T Gans & D O'Connell
Appl. Phys. Lett. 99, 041501 (2011)

The challenge of revealing and tailoring the dynamics of radio-frequency plasmas

T Gans, D O'Connell, V Schulz-von der Gathen & J Waskoenig
Plasma Sources Science and Technology, 19 (3), 034010 (2010)

Atomic oxygen formation in a radio-frequency driven micro-atmospheric pressure plasma jet

J Waskoenig, K Niemi, N Knake, L.M Graham, S Reuter, V Schulz-von der Gathen, T Gans
Plasma Sources Science and Technology, 19, 045018 (2010)

The role of the relative voltage and phase for frequency coupling in a dual-frequency capacitively coupled plasma

D O’Connell, T Gans, E Semmler, P Awakowicz
Appl. Phys. Lett., 93 081502 (2008)

Space and phase resolved plasma parameters in an industrial dual-frequency capacitively coupled radio-frequency discharge

J Schulze, T Gans, D O’Connell, U Czarnetzki, A.R Ellingboe, M.M Turner
Journal of Physics D: Applied Physics, 40 (2007) 7008

Plasma ionisation through wave particle interaction in a capacitively coupled

D O’Connell, T Gans, D Vender, U Czarnetzki & R Boswell
Physics of Plasmas, 14 (2007)

T Gans, J Schulze, D O’Connell, U Czarnetzki, R Faulkner, A.R Ellingboe, M.M Turner

Frequency coupling in dual-frequency capacitively coupled radio-frequency plasmas

Appl. Phys. Lett., 89 (2006) 261502

M Abdel-Rahman, V Schulz-von der Gathen, T Gans, K Niemi, H.F Döbele
Determination of the degree of dissociation in an inductively-coupled hydrogen plasma using optical emission spectroscopy and laser diagnostics

Plasma Sources Sci. Tech., 15 (2006) 620

T Gans, V Schulz-von der Gathen, H.F Döbele

Spectroscopic measurements of phase-resolved electron energy distribution functions in RF excited discharges

Europhysics Letters, 66 (2004) 232

T Gans, C. Lin Chun, V Schulz-von der Gathen, H.F Döbele 

Phase-resolved emission spectroscopy of a hydrogen rf discharge for the determination of quenching coefficients

Phys. Rev. A, 67 (2003) 012707

T Gans, V Schulz-von der Gathen, H.F Döbele
Time dependence of rotational state populations of excited hydrogen molecules in an rf excited plasma reactor

Plasma Sources Sci. Technol., 10 (2001) 17-23

A Goehlich, T Kawetzki, H.F Döbele 

On absolute calibration with xenon of laser diagnostic methods based on two-photon absorption

Journal of Chemical Physics, 108 (1998) 9362-9370