

Åshild Fredriksen
Professor / Plasma and Space Physics
- Buschmann, Lisa Marie; Fredriksen, Åshild. Axial and radial development of the hot electron distribution in a helicon plasma source, measured by a retarding field energy analyzer (RFEA). Plasma Sources Science & Technology 2022; Volum 31 (2). ISSN 0963-0252.s doi: 10.1088/1361-6595/ac47e5.
- Antonsen, Tarjei; Mann, Ingrid; Vaverka, Jakub; Nouzak, Libor; Fredriksen, Åshild. A comparison of contact charging and impact ionization in low-velocity impacts: implications for dust detection in space. Annales Geophysicae 2021; Volum 39 (3). ISSN 0992-7689.s 533 - 548.s doi: 10.5194/angeo-39-533-2021.
- Sado, Pascal; Fredriksen, Åshild. Detailed density and ion energy profiles downstream of a small ECR plasma source. IEEE Transactions on Plasma Science 2020; Volum 48 (12). ISSN 0093-3813.s 4181 - 4190.s doi: 10.1109/TPS.2020.3037356.
- Fredriksen, Åshild; Pécseli, Hans L; Trulsen, Jan Karsten. Anomalous transport due to large coherent structures in a magnetized toroidal plasma. Plasma Physics and Controlled Fusion 2020; Volum 63 (1). ISSN 0741-3335.s doi: 10.1088/1361-6587/abc518.
- Trollvik, Henriette Marie Tveitnes; Gunnarsdottir, Tinna; Mann, Ingrid; Olsen, Sveinung viggo; Restad, Erlend Sømhovd; Antonsen, Tarjei; Havnes, Ove; Fredriksen, Åshild; Boothby, Christoffer; Bjørk, Arne; Hansen, Rikke Hedelund; Floer, Markus; Eilertsen, Yngve; Latteck, Ralph. Observation of mesospheric dust and ionospheric conditions during the G-chaser rocket campaign. ESA SP 2019. ISSN 0379-6566.
- Gunnarsdottir, Tinna; Trollvik, Henriette; Mann, Ingrid; Olsen, Sveinung viggo; Eilertsen, Yngve; Antonsen, Tarjei; Restad, Erlend Sømhovd; Bjørk, Arne; Havnes, Ove; Fredriksen, Åshild; Boothby, Christoffer; Hansen, Rikke Hedelund; Floer, Markus. CHARGING AND DETECTION OF MESOSPHERIC DUST WITH INSTRUMENT SPID ON G-CHASER ROCKET. ESA SP 2019. ISSN 0379-6566.
- Mann, Ingrid; Nouzák, Libor; Vaverka, Jakub; Antonsen, Tarjei; Fredriksen, Åshild; Issautier, Karine; Malaspina, David; Meyer-Vernet, Nicole; Pavlů, Jiří; Sternovsky, Zoltan; Stude, Joan; Ye, Shengyi; Zaslavsky, Arnaud. Dust observations with antenna measurements and its prospects for observations with Parker Solar Probe and Solar Orbiter. Annales Geophysicae 2019; Volum 37 (6). ISSN 0992-7689.s 1121 - 1140.s doi: 10.5194/angeo-37-1121-2019.
- Varberg, Erik; Fredriksen, Åshild. Effect of permanent magnets on plasma confinement and ion beam properties in a double layer helicon plasma source. Journal of Plasma Physics 2019; Volum 85 (3). ISSN 0022-3778.s 905850310 - .s doi: 10.1017/S0022377819000412.
- Havnes, Ove; Antonsen, Tarjei; Baumgarten, Gerd; Hartquist, Thomas W.; Biebricher, Alexander; Fredriksen, Åshild; Friedrich, Martin; Hedin, Jonas. A new method of inferring the size, number density, and charge of mesospheric dust from its in situ collection by the DUSTY probe. (data) Atmospheric Measurement Techniques 2019; Volum 12 (3). ISSN 1867-1381.s 1673 - 1683.s doi: 10.5194/amt-12-1673-2019.
- Fredriksen, Åshild; Pecseli, Hans; Trulsen, Jan Karsten. A solvable model for the basic properties of a simple magnetized plasma torus. Plasma Physics and Controlled Fusion 2018; Volum 60:085021 (8). ISSN 0741-3335.s doi: 10.1088/1361-6587/aacd2a.
- Gulbrandsen, Njål; Fredriksen, Åshild. RFEA Measurements of High-Energy Electrons in a Helicon Plasma Device with Expanding Magnetic Field. Frontiers in Physics 2017; Volum 5. ISSN 2296-424X.s 1 - 8.s doi: 10.3389/fphy.2017.00002.
- Bhattacharjee, Sudeep; Fredriksen, Åshild; Chandra, Sayan. Fluctuations in electron cyclotron resonance plasma in a divergent magnetic field. Physics of Plasmas 2016; Volum 23 (2). ISSN 1070-664X.s 1 - 7.s doi: 10.1063/1.4941595.
- Havnes, Ove; Antonsen, Tarjei; Hartquist, Thomas W.; Fredriksen, Åshild; Plane, John M.C.. The Tromsø programme of in situ and sample return studies of mesospheric nanoparticles. Journal of Atmospheric and Solar-Terrestrial Physics 2015; Volum 127. ISSN 1364-6826.s 129 - 136.s doi: 10.1016/j.jastp.2014.09.010.
- Gulbrandsen, Njål; Fredriksen, Åshild; Carr, Jr, Jerry; Scime, Earl. A comparison of ion beam measurements by retarding field energy analyzer and laser induced fluorescence in helicon plasma devices. Physics of Plasmas 2015; Volum 22 (3). ISSN 1070-664X.s doi: 10.1063/1.4913990.
- Bergsaker, Anne Schad; Fredriksen, Åshild; Pecseli, Hans; Trulsen, Jan Karsten. Models for the probability densities of the turbulent plasma flux in magnetized plasmas. Physica Scripta 2015; Volum 90 (10). ISSN 0031-8949.s doi: 10.1088/0031-8949/90/10/108005.
- Fredriksen, Åshild; Gulbrandsen, Njål. Beam formation in a weakly collisional expanding, inductively coupled plasma.. (sammendrag) IEEE Sarnoff Symposium 2014 ISBN 978-1-4673-5225-3.s doi: 10.1109/ursigass.2014.6929899.
- Bergsaker, Anne Schad; Fredriksen, Åshild; Pecseli, Hans; Trulsen, Jan Karsten. Analytical models for skewness-kurtosis relations in turbulent transport. (fulltekst) 2014 ISBN 2-914771-90-8.
- Gulbrandsen, Njål; Fredriksen, Åshild. The role of collisions for beam formation in a plasma potential gradient. (fulltekst) 2014 ISBN 2-914771-90-8.
- Havnes, Ove; Antonsen, Tarjei; Fredriksen, Åshild; Olsen, Sveinung Viggo; Eilertsen, Yngve; Strømmesen, Inge o. ICON, A MASS ANALYZER FOR THE ICE CONTENT OF NLC/PMSE PARTICLES. ESA SP 2013. ISSN 0379-6566.s 441 - 444.
- Gulbrandsen, Njål; Miloch, Wojciech Jacek; Fredriksen, Åshild. Interpretation of Ion Velocity Distributions Measured with a Grounded Retarding Field Energy Analyzer (RFEA) in an Inductively Coupled Helicon Plasma. Contributions to Plasma Physics 2013; Volum 53 (1). ISSN 0863-1042.s 27 - 32.s doi: 10.1002/ctpp.201310005.
- Fredriksen, Åshild; Miloch, Wojciech Jacek; Gulbrandsen, Njål; Mishra, Lekha Nath. On the Use of a Retarding Field Energy Analyzer for Plasma Flow Analysis. Contributions to Plasma Physics 2013; Volum 53 (1). ISSN 0863-1042.s 86 - 91.s doi: 10.1002/ctpp.201310015.
- Barni, R.; Riccardi, C; Fredriksen, Åshild. Structure dynamics associated with temperature fluctuations in the magnetised plasma of the Thorello device. (fulltekst) Curran Associates, Inc. 2012 ISBN 9781618395931.s 632 - 636.
- Fattorini, L.; Fredriksen, Åshild; Pecseli, Hans; Riccardi, C.; Trulsen, Jan Karsten. Turbulent transport in a toroidal magnetized plasma. Plasma Physics and Controlled Fusion 2012; Volum 54 (8). ISSN 0741-3335.s doi: 10.1088/0741-3335/54/8/085017.
- Miloch, Wojciech Jacek; Gulbrandsen, Njål; Mishra, Lekha Nath; Fredriksen, Åshild. Ion velocity distributions in the sheath and presheath of a biased object in plasma. Physics of Plasmas 2011; Volum 18 (8). ISSN 1070-664X.s doi: 10.1063/1.3614520.
- Fredriksen, Åshild; Mishra, Lekha Nath; Byhring, Hanne Sigrun. The effects of downstream magnetic field on current-free double layers and beam formation in the Njord helicon plasma device. Plasma Sources Science & Technology 2010; Volum 19 (3). ISSN 0963-0252.s doi: 10.1088/0963-0252/19/3/034009.
- Fredriksen, Åshild; Mishra, Lekha Nath; Gulbrandsen, Njål; Miloch, Wojciech Jacek. On the measurement of subsonic flow in a capacitevly coupled helicon plasma source. (data) Journal of Physics: Conference Series (JPCS) 2010; Volum 257. ISSN 1742-6588.s doi: 10.1088/1742-6596/257/1/012019.
- Miloch, Wojciech Jacek; Gulbrandsen, Njål; Mishra, Lekha Nath; Fredriksen, Åshild. The role of acceptance angle in measurements with ion energy analyzers: Study by numerical simulations. (data) Applied Physics Letters 2010; Volum 97 (26). ISSN 0003-6951.s doi: 10.1063/1.3531757.
- Fredriksen, Åshild; Borg, Anne. Report from Norway on the Participation of Women in Physics. 2009 (1119) ISBN 978-0-7354-0645-2. ISSN 0094-243X.s 149 - 150.
- Fredriksen, Åshild; Byhring, Hanne Sigrun; Charles, Christine; Mishra, Lekha Nath; Boswell, Rod. Double Layer Beam Formation in the Njord Device and its Dependence on Magnetic Field Configuration. 2008 ISBN 2914771525.
- Riccardi, Claudia; Barni, Ruggero; Roman, Eduardo; Fredriksen, Åshild. Anomalous fluctuations in the simple magnetized plasma. Research Signpost 2008 ISBN 9788130802558.s 123 - 144.
- Byhring, Hanne Sigrun; Charles, Christine; Fredriksen, Åshild; Boswell, Rod. Double layer in an expanding plasma: Simultaneous upstream and downstream measurements. Physics of Plasmas 2008; Volum 15 (10). ISSN 1070-664X.s doi: 10.1063/1.3002396.
- Fredriksen, Åshild; Fredriksen, A.A.; Pecseli, Hans L.; Trulsen, Jan. Crash and recovery of the potential in a toroidal plasma column, as observed by generalized conditional sampling. New Journal of Physics 2008; Volum 10 (033030). ISSN 1367-2630.s doi: 10.1088/1367-2630/10/3/033030.
- Fredriksen, Åshild; Riccardi, Claudia; Magni, Simone. Effects of edge dc biasing on plasma rotation and transport in a toroidal geometry. Physica Scripta 2006; Volum T122. ISSN 0031-8949.
- Fredriksen, Åshild; Riccardi, Claudia; Roman, Eduardo; Barni, Ruggero. Coherent structures in sheared velocity flow. 2006 ISBN 2-914771-40-1.
- Aanesland, Ane; Charles, C.; Boswell, R.; Fredriksen, Åshild. Fluctuation in a Helicon plasma with additional immersed antenna. IEEE Transactions on Plasma Science 2005; Volum 33. ISSN 0093-3813.
- Levinton, Fred; Fredriksen, Åshild. Diagnostic method for the measurement of coherent magnetic field fluctuations. Review of Scientific Instruments 2004; Volum 75 (10). ISSN 0034-6748.s 4162 - 4164.
- Riccardi, Claudia; Barni, Ruggero; Fredriksen, Åshild. Determination of velocity shears in a simple magnetized torus by means of a combined Langmuir and Mach probe. Review of Scientific Instruments 2004; Volum 75 (10). ISSN 0034-6748.s 4341 - 4343.
- Aanesland, Ane; Charles, Christine; Boswell, Rod; Fredriksen, Åshild. Helicon plasma with additional immersed antenna. Journal of Physics D: Applied Physics 2004; Volum 37 (9). ISSN 0022-3727.s 1334 - 1341.
- Fredriksen, Åshild; Riccardi, C.; Cartegni, L; Draghi, D; Battistoni, R. Trasarti; Roman, H. E.. Statistical analysis of turbulent flux and intermittency in the non-fusion magnetoplasma Blaamann. Physics of Plasmas 2003 (10). ISSN 1070-664X.s 4335 - 4340.
- Fredriksen, Åshild; Riccardi, C.; Cartegni, L; Pecseli, Hans L.. Coherent structures and intermittency in Blaamann. Plasma Physics and Controlled Fusion 2003; Volum 45. ISSN 0741-3335.s 721 - 733.
- Fredriksen, Åshild; Riccardi, C.; Cartegni, L. Measurements of coherent structures and transport in the full cross section of magnetized plasma. Review of Scientific Instruments 2003; Volum 74. ISSN 0034-6748.s 1588 - 1591.
- Aanesland, Ane; Charles, Christine; Boswell, Rod; Fredriksen, Åshild. Sputtering effects in a helicon plasma with an additional immersed antenna. Plasma Sources Science & Technology 2003; Volum 12. ISSN 0963-0252.s 85 - 88.
- Aanesland, Ane; Fredriksen, Åshild. ECR harmonics and wall material effects in a microwave disharge. Review of Scientific Instruments 2003; Volum 74. ISSN 0034-6748.s 4336 - 4341.
- Toader, E.I.; Fredriksen, Åshild; Aanesland, Ane. Complex structure of the electronic energy distribution function observed in electron cyclotron resonance nitrogen plasma. Review of Scientific Instruments 2003 (74). ISSN 0034-6748.s 3279 - 3283.
- Fredriksen, Åshild. Plasma- og gassutladningssympoiet 2002. Fra Fysikkens Verden 2002 (2). ISSN 0015-9247.s 52 - .
- Fredriksen, Åshild; Riccardi, C.; Longoni, G.. Diagnostic of electron temperature fluctuations in a turbulent plasma. Review of Scientific Instruments 2001; Volum 72. ISSN 0034-6748.s 457 - .
- Riccardi, C.; Fredriksen, Åshild. Waves and coherent structures in the turbulent plasma of a simple magnetized torus. Physics of Plasmas 2001; Volum 8. ISSN 1070-664X.s 199 - 209.
- Aanesland, Ane; Fredriksen, Åshild. Pressure and density dependent mode transition in an electron cyclotron resonance plasma. Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films 2001; Volum 19. ISSN 0734-2101.s 2446 - 2452.
- Riccardi, C.; Chiodini, G.; Bevilacqua, C.; Barni, R.; Fredriksen, Åshild; Fontanesi, M.. Bohm like Transport in a Toroidal Magnetoplasma in the Absence of Longitudinal Current. Physica Scripta 2000; Volum T84. ISSN 0031-8949.s 103 - 106.
- Øynes, F. J.; Olsen, O.-M.; Pecseli, Hans L.; Fredriksen, Åshild; Rypdal, Kristoffer. Experimental study of low-frequency electrstatic fluctuations in a magnetized toroidal plasma. Physical Review E. Statistical, Nonlinear, and Soft Matter Physics 1998; Volum 57. ISSN 1539-3755.s 2242 - 2255.
- Rypdal, Kristoffer; Fredriksen, Åshild; Olsen, O. M.; Hellblom, G.. Microwave Plasma in a Simple Magnetized Torus. Physics of Plasmas 1997; Volum 4. ISSN 1070-664X.s 1468 - 1480.
- Armstrong, Richard; Fredriksen, Åshild; Grønvoll, E.; Batani, D.; Galassi, A.; Pisani, F.. Measurements of Ion Temperature in Weakly Ionised, Steady-State Plasmas. Physics essays 1997; Volum 10 (3). ISSN 0836-1398.s 483 - 491.
- Hwang, Y. S.; Fredriksen, Åshild; Qin, H; Forest, C. B.; Ono, M.. Polarimetry for the CDX-U tokamak. Review of Scientific Instruments 1995; Volum 66. ISSN 0034-6748.s 379 - 381.
- Rypdal, Kristoffer; Grønvoll, E.; Øynes, F. J.; Fredriksen, Åshild; Armstrong, Richard; Trulsen, Jan; Pecseli, Hans L.. Confinement an turbulent transport in a plasma torus with no rotational transform. Plasma Physics and Controlled Fusion 1994; Volum 36. ISSN 0741-3335.s 1099 - 1114.
- Fredriksen, Åshild; Bjørnå, Noralv; Lilensten, J.. Incoherent Scatter Plasma Lines at Angles with the Magnetic Field. Journal of Geophysical Research (JGR) 1992; Volum 97. ISSN 0148-0227.s 16921 - 16933.
- Fredriksen, Åshild; La Hoz, Cesar. Measurements of Chirped Natural Plasma Lines with EISCAT. Advances in Space Research 1991; Volum 12 (6). ISSN 0273-1177.s 231 - 234.
- Fredriksen, Åshild. High Latitude Quiet Summer Ion Composition Profiles Derived from a Combined Ion Line/ Plasma Line Incoherent Scatter Eperiment. Journal of Atmospheric and Terrestrial Physics 1990; Volum 52. ISSN 0021-9169.s 77 - 84.
- Fredriksen, Åshild; Bjørnå, Noralv; Hansen, Truls Lynne. First EISCAT Two-Radar Plasma-Line Experiment. Journal of Geophysical Research (JGR) 1989; Volum 94. ISSN 0148-0227.s 2727 - 2731.
- Armstrong, Richard; Fredriksen, Åshild; Pecseli, Hans L.; Trulsen, Jan. Electron Bernstein Waves in Inhomogeneous Magnetic Fields. Plasma Physics and Controlled Fusion 1984; Volum 26. ISSN 0741-3335.s 703 - 716.
Research interests
Experimental plasma physics, acceleration and heating processes, electric double layers, turbulence and turbulent structures, plasma diagnostics.
See also the Aurolab pages.
Teaching
Fys-3017/8017: Sheaths and probes in low-temperature plasmas .
Contact me if you are interested in this course spring 2020.