Mobilities of Charge Carriers in Superfluid Helium

Schwarz, K. W.

doi:10.1002/9780470142523.ch1

Cited by 64 publications

(5 citation statements)

References 105 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…A positive ion is a microscopic sphere of solid helium ("snowball") of radius ∼7 Å around a helium molecular ion, while a negative ion is simply an excess electron in liquid helium that self-localizes in a spherical cavity ("electron bubble") of radius ∼20 Å devoid of helium [51,52]. For reviews on the properties and use of injected ions in liquid helium see [10,[53][54][55]. Ions are attracted to vortex cores and once trapped stay on the cores essentially forever provided that the temperature is sufficiently low (T < 1.7 K for negative ions in 4 He at STP).…”

Section: Detection Of Turbulence In 4 He At T < 1 Kmentioning

confidence: 99%

See 1 more Smart Citation

Homogeneous Turbulence in Superfluid 4He in the Low-Temperature Limit: Experimental Progress

Golov

Walmsley

2009

J Low Temp Phys

View full text Add to dashboard Cite

Selected advances in the research on the dynamics of tangles of quantized vortices in superfluid helium with little normal component during the last 50 years are briefly reviewed. The main emphasis is on the experimental techniques of generating and probing homogeneous one-component superfluid turbulence of various energy spectra in superfluid 4 He in the low-temperature limit. The most recent experimental progress, modern theoretical concepts and future outlook are summarized.

show abstract

Section: Detection Of Turbulence In 4 He At T < 1 Kmentioning

confidence: 99%

“…J Low Temp Phys (2009) 156:[51][52][53][54][55][56][57][58][59][60][61][62][63][64][65][66][67][68][69][70] …”

unclassified

Homogeneous Turbulence in Superfluid 4He in the Low-Temperature Limit: Experimental Progress

Golov

Walmsley

2009

J Low Temp Phys

View full text Add to dashboard Cite

show abstract

“…Positively charged ions have frequently been studied in liquid helium where they can be solvated and where they are known to produce clustersoften referred to as “snowballs”. − However, whether clusters exist at low temperatures above T c is currently an open question. Measurements of positive ion mobility in the supercritical phase could shed light on this issue, but to the best of our knowledge no data is available to date.…”

mentioning

confidence: 99%

“…[7][8][9][10][11] But whether clusters exist at low temperatures above T c is currently an open question. Measurements of positive ion mobility in the supercritical phase could shed light on this issue, but to the best of our knowledge no data is available to date.…”

mentioning

confidence: 99%

Formation of Positively Charged Liquid Helium Clusters in Supercritical Helium and their Solidification upon Compression

Tarchouna

Bonifaci

Aitken

et al. 2015

J. Phys. Chem. Lett.

View full text Add to dashboard Cite

Positively charged ions were produced in supercritical helium at temperatures from 6 to 10 K and up to 2 MPa using a corona discharge. Their mobility was measured via currentvoltage curves and the hydrodynamic radius was derived using Stokes law. An initial increase and subsequent decrease of hydrodynamic radius was observed and interpreted in terms of growth, compression and solidification of ion clusters. The mobility was modelled using a van der Waals-type thermodynamic state equation for the ion-in-helium mixed system and a temperature-dependent Millikan-Cunningham factor, describing experimental data both in the Knudsen and the Stokes flow region. Regions of maximum hydrodynamic radius and large 1

show abstract

“…An excess electron, injected into the strongly-repelling liquid helium environment, quickly self-localizes in a cavity of radius ∼19 Å, from which all helium atoms are expelled [24][25][26]. We call such a bubble containing an electron a "negative ion".…”

mentioning

confidence: 99%

Charged Tangles of Quantized Vortices in Superfluid 4He

2010

View full text Add to dashboard Cite

We show that turbulence in superfluid 4 He at low temperatures can be generated and probed by injected ions trapped on vortex cores. The results of our recent experiments, in which negative ions were injected during short and long periods, in different quantities, and into different applied electric fields, are outlined. Three very different mechanisms of vortex-assisted transport of trapped ions were observed: one is on isolated vortex rings while two others are associated with tangles of vortex lines. It seems there are two different types of vortex tangles that can be characterized by the velocity of ion motion through them: a drifting polarized tangle in a low-dissipation state that mainly advects trapped ions, and a more isotropic tangle in a highly-dissipative state, sustained by a continuous forcing by the ion current in an applied electric field, through which trapped ions move rapidly.

show abstract

Mobilities of Charge Carriers in Superfluid Helium

Cited by 64 publications

References 105 publications

Homogeneous Turbulence in Superfluid 4He in the Low-Temperature Limit: Experimental Progress

Homogeneous Turbulence in Superfluid 4He in the Low-Temperature Limit: Experimental Progress

Formation of Positively Charged Liquid Helium Clusters in Supercritical Helium and their Solidification upon Compression

Charged Tangles of Quantized Vortices in Superfluid 4He

Contact Info

Product

Resources

About