Ionization of water clusters by collisions with graphite surfaces

Andersson, Patrik; Pettersson, Jan B. C.

doi:10.1007/s004600050289

Cited by 52 publications

(42 citation statements)

References 29 publications

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“…Similar effects have been observed in laboratory experiments with small ice particles with sizes of the order of 10 nm impacting on surfaces, with velocities of ∼1 km/s (e.g. Andersson and Pettersson, 1997;Tomsic, 2001;Gridin et al, 2004). The required effectivity for the secondary charge production of the mesospheric dust is much larger than what is observed for pure water-ice particles in experiments.…”

Section: Introductionsupporting

confidence: 75%

Mesospheric dust and its secondary effects as observed by the ESPRIT payload

Havnes

Surdal²,

Philbrick

2009

Ann. Geophys.

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Abstract. The dust detector on the ESPRIT rocket detected two extended dust/aerosol layers during the launch on 1 July 2006. The lower layer at height ∼81.5-83 km coincided with a strong NLC and PMSE layer. The maximum dust charge density was ∼−3.5×10 9 e m −3 and the dust layer was characterized by a few strong dust layers where the dust charge density at the upper edges changed by factors 2-3 over a distance of 10 m, while the same change at their lower edges were much more gradual. The upper edge of this layer is also sharp, with a change in the probe current from zero to I DC =−10 −11 A over ∼10 m, while the same change at the low edge occurs over ∼500 m. The second dust layer at ∼85-92 km was in the height range of a comparatively weak PMSE layer and the maximum dust charge density was ∼−10 8 e m −3 . This demonstrates that PMSE can be formed even if the ratio of the dust charge density to the electron density P =N d Z d /n e 0.01.In spite of the dust detector being constructed to reduce possible secondary charging effects from dust impacts, it was found that they were clearly present during the passage through both layers. The measured secondary charging effects confirm recent results that dust in the NLC and PMSE layers can be very effective in producing secondary charges with up to ∼50 to 100 electron charges being rubbed off by one impacting large dust particle, if the impact angle is θ i 20-35 • . This again lends support to the suggested model for NLC and PMSE dust particles (Havnes and Naesheim, 2007) as a loosely bound water-ice clump interspersed with a considerable number of sub-nanometer-sized meteoric smoke particles, possibly also contaminated with meteoric atomic species.

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Section: Introductionsupporting

confidence: 75%

Mesospheric dust and its secondary effects as observed by the ESPRIT payload

Havnes

Surdal²,

Philbrick

2009

Ann. Geophys.

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“…This effect is minimized by having the collection surfaces within an enclosure and by having graphite collection surfaces which have a low photoelectron yield (Feuerbacher and Fitton, 1972). The second effect is the generation of charged fragments created by the impact of ice particles that has been observed in laboratory experiments (Vostrikov et al, 1987(Vostrikov et al, , 1988(Vostrikov et al, , 1997Andersson and Pettersson, 1997) and proposed as an explanation for some signals from rocketborne instruments (Havnes and Naesheim, 2007). Charge generation is largest for the aerosol particles with the greatest mass.…”

Section: The Mass Payloadsmentioning

confidence: 99%

Mass analysis of charged aerosol particles in NLC and PMSE during the ECOMA/MASS campaign

et al. 2009

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Abstract. MASS (Mesospheric Aerosol Sampling Spectrometer) is a multichannel mass spectrometer for charged aerosol particles, which was flown from the Andøya Rocket Range, Norway, through NLC and PMSE on 3 August 2007 and through PMSE on 6 August 2007. The eight-channel analyzers provided for the first time simultaneous measurements of the charge density residing on aerosol particles in four mass ranges, corresponding to ice particles with radii <0.5 nm (including ions), 0.5-1 nm, 1-2 nm, and >3 nm (approximately). Positive and negative particles were recorded on separate channels. Faraday rotation measurements provided electron density and a means of checking charge density measurements made by the spectrometer. Additional complementary measurements were made by rocket-borne dust impact detectors, electric field booms, a photometer and ground-based radar and lidar. The MASS data from the first flight showed negative charge number densities of 1500-3000 cm −3 for particles with radii >3 nm from 83-88 km approximately coincident with PMSE observed by the ALWIN radar and NLC observed by the ALOMAR lidar. For particles in the 1-2 nm range, number densities of positive and negative charge were similar in magnitude (∼2000 cm −3 ) and for smaller particles, 0.5-1 nm in radius, positive charge was dominant. The occurrence of positive charge on the aerosol particles of the smallest size and predominately negative charge on the particles of largest size suggests that nucleCorrespondence to: S. Knappmiller (knappmil@colorado.edu) ation occurs on positive condensation nuclei and is followed by collection of negative charge during subsequent growth to larger size. Faraday rotation measurements show a bite-out in electron density that increases the time for positive aerosol particles to be neutralized and charged negatively. The larger particles (>3 nm) are observed throughout the NLC region, 83-88 km, and the smaller particles are observed primarily at the high end of the range, 86-88 km. The second flight into PMSE alone at 84-88 km, found only small number densities (∼500 cm −3 ) of particles >3 nm in a narrow altitude range, 86.5-87.5 km. Both positive (∼2000 cm −3 ) and negative (∼4500 cm −3 ) particles with radii 1-2 nm were detected from 85-87.5 km.

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“…Impact ionization could also change the apparent depth of the biteout. The laboratory measurements of Andersson and Pettersson [1997] show that either positive or negative charge fragments can result from such collisions. Our companion paper [Mitchell et al, submitted to GRL] discusses impact ionization effects on the blunt probes that were also part of the DROPPS payload.…”

Section: Observational Techniquesmentioning

confidence: 99%

Electrical structure of PMSE and NLC regions during the DROPPS Program

Croskey¹,

Mitchell²,

Friedrich³

et al. 2001

Geophysical Research Letters

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Abstract. The electrical structure of NLC/PMSE regions was investigated by different rocket-borne in situ probe techniques as part of the DROPPS program. Gerdien condenser measurements of very small mobility values suggest concentrations of positively charged aerosols/dust comparable to the density of more mobile positive ions at PMSE/NLC altitudes. Relative electron density values and associated large-and small-scale vertical structure measured by DC Langmuir probes revealed very deep (by a factor of 50) biteouts in PMSE/NLC regions. These biteouts were seen during strong and weak NLC conditions when PMSEs were either present or absent.

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Ionization of water clusters by collisions with graphite surfaces

Cited by 52 publications

References 29 publications

Mesospheric dust and its secondary effects as observed by the ESPRIT payload

Mesospheric dust and its secondary effects as observed by the ESPRIT payload

Mass analysis of charged aerosol particles in NLC and PMSE during the ECOMA/MASS campaign

Electrical structure of PMSE and NLC regions during the DROPPS Program

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