Heidelberg 2015 – wissenschaftliches Programm
UP 7.4: Vortrag
Donnerstag, 26. März 2015, 12:30–12:45, C/gHS
Miniature High Sensitive Time-of-Flight Noble gas Mass spectrometer for very low gas measurements — •Ramakrishna Ramisetty and Ingo Leya — University of Bern, Space Research and Planetary Sciences,Bern, Switzerland
Noble gas analysis in early solar system materials, which can provide valuable information about early solar system processes and timescales, are very challenging because of extremely low noble gas concentrations (ppt). We therefore developed a new, high sensitive, compact sized (33 cm length, 7.2cm diameter, 1.3 L internal volume) Time-of-Flight (TOF) noble gas mass spectrometer. The instrument uses electron impact ionization coupled to an ion trap, which allows us to ionize and measure all noble gas isotopes with high efficiency. Using a reflectron set-up we reach a mass resolution of >1000amu. In addition, the reflectron set-up also enables some extra focusing. The detection is via MCPs and the signals are processed either via ADC or TDC systems. The instrument can be tuned automatically and under normal operational conditions the electronics and valves are fully computer controlled Noble gas calibrations showed a detection limit in the range 10-14 cm3STP and about 7 orders of dynamic range.