Welcome to the LMS Homepage

The Laser-Abation Time-of-Flight Mass Spectrometer instrument (LMS) at the Physikalisches Institut of the University of Bern is designed for in-situ measurements with high acuracy and sensitivity for elemental and isoptopic composition measurements of regolith material on celestial objects. High accurate measurements on major, minor and especially trace elements down to the ppb range and on isotopic ratios play a crucial role for a depper and better understanding on the evolution of our planetery system and the question of the origin of life.

The experimental system consists of a pulsed laser ablation ion source, a miniaturised reflectron-time-of-flight mass spectrometer and a dedicated experimental optimisation part. The pulsed laser beam enters the mass analyser through a window at the top of the vacuum chamber and a focusing lens. The focused beam passes the mass analyser, the detection assembly and finally the ion optical system before reaching the sample surface. Positive ions generated in the plasma plume enter the mass analyser through the conical nose-piece, and are accelerated, confined, and collimated by an electrostatic immersion lens. The ions passe the field-free region and are backreflected by the reflectron towards the multichannel plate (MCP) detector. The ions arrive at the MCP detector in sequence, at times proportional to the square root of their mass-to-charge ratio (m/q).

There are images of the experiment available as well as an up to date list of publications that contain data obtained with the LMS instrument.


Physics Institute, Space Research and Planetary Sciences
Sidlerstrasse 5, 3012 Bern, Switzerland

Tel: +41 (0) 31 631 4411
Fax: +41 (0) 31 631 4405