V51A-3027
New Developments in 40Ar/39Ar Geochronology: the Contribution of the Helix MC
Friday, 18 December 2015
Poster Hall (Moscone South)
Klaudia Kuiper1, Marilyn Monster2, Alessandro Santato3, Doug Hamilton4, Evelien Rost1 and Jan R Wijbrans5, (1)VU University Amsterdam, Faculty of Earth and Life Sciences, Amsterdam, Netherlands, (2)Utrecht University, Utrecht, Netherlands, (3)Thermo Fisher, Bremen, Germany, (4)Thermo Scientific, Bremen, Germany, (5)Free University of Amsterdam, Amsterdam, Netherlands
Abstract:
The 40Ar/39Ar community is moving from a single collector to multi-collector beam detection approach with the Noblesse and Argus VI mass spectrometers as the main proponents of this transition. In addition, new approaches for the detection of individual ion beams have already been introduced such as Faraday collectors with 1012 and 1013 Ohm resistor amplifiers. Here, we report our initial findings on a relatively new branch on the tree: the high resolution Helix MC. The Helix is fitted with 5 Faraday collectors with 1012 and 1013 Ohm amplifiers and 5 compact discrete dynode secondary electron multipliers for pulse counting detection on each channel. The design of the instrument includes a 120 degrees deflection magnet with a measured standard resolution of ca 900. The high resolution mode on channel L2 has a resolution of ca 1700 and is used for the detection of 36Ar. Here, we will explain the most important aspects of our newly developed analytical protocols, report the first data and discuss some of the implications of our findings for Earthtime targets.
