Chandrayaan-1 observations of backscattered solar wind protons from the lunar regolith: Dependence on the solar wind speed

Lue, Charles; Futaana, Yoshifumi; Barabash, Stas; Wieser, Martin; Bhardwaj, Anil; Wurz, Peter (2014). Chandrayaan-1 observations of backscattered solar wind protons from the lunar regolith: Dependence on the solar wind speed. Journal of Geophysical Research: Planets, 119(5), pp. 968-975. AGU Publications 10.1002/2013JE004582

[img]
Preview
Text
jgre20243.pdf - Published Version
Available under License Publisher holds Copyright.

Download (882kB) | Preview

We study the backscattering of solar wind protons from the lunar regolith using the Solar Wind Monitor of the Sub-keV Atom Reflecting Analyzer on Chandrayaan-1. Our study focuses on the component of the backscattered particles that leaves the regolith with a positive charge. We find that the fraction of the incident solar wind protons that backscatter as protons, i.e., the proton-backscattering efficiency, has an exponential dependence on the solar wind speed that varies from ~0.01% to ~1% for solar wind speeds of 250 km/s to 550 km/s. We also study the speed distribution of the backscattered protons in the fast (~550 km/s) solar wind case and find both a peak speed at ~80% of the solar wind speed and a spread of ~85 km/s. The observed flux variations and speed distribution of the backscattered protons can be explained by a speed-dependent charge state of the backscattered particles.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Physics Institute > Space Research and Planetary Sciences

UniBE Contributor:

Wurz, Peter

Subjects:

500 Science > 530 Physics

ISSN:

2169-9097

Publisher:

AGU Publications

Language:

English

Submitter:

Cléa Serpollier

Date Deposited:

16 Apr 2015 09:28

Last Modified:

16 Apr 2015 09:28

Publisher DOI:

10.1002/2013JE004582

BORIS DOI:

10.7892/boris.66768

URI:

https://boris.unibe.ch/id/eprint/66768

Actions (login required)

Edit item Edit item
Provide Feedback