W. M. KECK ISOTOPE LABORATORY

Thermal Ionization Mass Spectrometer

Housed in the W.M. Keck Isotope Laboratory is a VG Sector 54 thermal ionisation mass spectrometer. This instrument was acquired in 1988 and has remained in full working order since. The Sector 54 is equipped with 9 fully moveable faraday collectors and a Daly ion counter behind a WARP filter. In 2003 the nine Solartron digital voltmeters were replaced with a single multiplexing unit with improved linearity over the dynamic range of the system.

Since its installation the Sector 54 has been used to make high precision isotope measurements of Sr, Rb, Nd, Sm, Pb, U, Th, Ra, Pa and Ca isotopes. Some of these isotopes (Pb, Nd, U and Th) can now be measured on the Neptune with similar levels of precision but with considerably greater ease and substantially more quickly.

Samples for the TIMS must be chemically purified. This can be carried out in the Wet Labs within the Keck Isotope Lab. These purified samples are loaded onto degassed filaments which are then mounted onto a turret and installed into the mass spectrometer.

Analyses of standards typically yield:

Instrument time can be requested by contacting Caroline Harris.