Cosmogenic Potassium in Iron Meteorites

Khan, Hammad (2022). Cosmogenic Potassium in Iron Meteorites (Unpublished). (Dissertation, Universität Bern, Physikalisches Institut)

[img] Text
Khan_Hammad_Defense.pdf - Other
Restricted to registered users only
Available under License BORIS Standard License.

Download (2MB)

This project aims to reintroduce the 41K-K Cosmic ray exposure (CRE) age dating system for iron
meteorites. For this, very low amounts of potassium isotopes need to be extracted from the iron
meteorite. Attempts using chemical extraction methods, i.e., digestion of the sample, subsequent
oxidation of the iron, and finally separation of the potassium were unsuccessful. The resulting blank
would have been much too high for our purpose. Therefore, a more physical extraction system based
on the ideas of Voshage and Hintenberger (1959) was planned, designed, and built. The novel
instrument for the extraction of cosmogenic potassium isotopes consists of a Radio Frequency (RF)
heating coil, heating a metal crucible (Tantalum or Molybdenum). Inside this metal crucible there is a
BN or graphite liner to protect the metal from oxidation. The potassium, which forms positive ions in
the melt, is volatilised and electrostatically attracted by and implanted onto a negatively charged
filament. This filament is then used in a normal double filament set-up of the Thermal Ionisation Mass
Spectrometer (TIMS).

Item Type:

Thesis (Dissertation)

Division/Institute:

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

UniBE Contributor:

Khan, Hammad Muhammad

Subjects:

500 Science > 520 Astronomy
600 Technology > 620 Engineering

Language:

English

Submitter:

Dora Ursula Zimmerer

Date Deposited:

03 Nov 2023 10:31

Last Modified:

03 Nov 2023 10:31

BORIS DOI:

10.48350/188541

URI:

https://boris.unibe.ch/id/eprint/188541

Actions (login required)

Edit item Edit item
Provide Feedback