6533b7d2fe1ef96bd125f3b7

RESEARCH PRODUCT

A compact apparatus for mass selective resonance ionization spectroscopy in a buffer gas cell

P. ThörleWerner LauthM. HiesR. FeldmannH. KunzKlaus EberhardtM. SewtzNorbert TrautmannH. J. SchöpeS. ZaunerHartmut BackeR. MartinP. Schwamb

subject

Nuclear and High Energy PhysicsArgonBuffer gasAnalytical chemistrychemistry.chemical_elementMass spectrometryIon sourceAtmospheric-pressure laser ionizationchemistryIonizationAtomic physicsInstrumentationQuadrupole mass analyzerElectron ionization

description

Abstract An ultra-sensitive laser spectroscopic method for the investigation of transuranium nuclides has been developed based on resonance ionization in an argon buffer gas cell. This method has been combined with ion-guide extraction and mass selective direct detection of the resonantly ionized atoms. Using argon as a buffer gas, recoils of fusion reactions can be thermalized even at low pressure. The differential pumping system consists of only one roots pump and two turbo molecular pumps. The set-up has been tested with 243 Am evaporated from a filament located inside the optical gas cell. Resonance ionization is performed using a two-step excitation with an excimer-dye-laser combination. The ions are transported by a suitable electrical field to the nozzle, and are ejected with the ion-guide gas jet into an electrostatic lens system followed by a quadrupole mass spectrometer and a channeltron detector. The total sensitivity has been measured to be 1.0 × 10 −4 . The extraction time for ions based on electric field guidance amounts to 1.5 ms, which is two orders of magnitude faster than the ion-guide gas exchange time of this set-up.

https://doi.org/10.1016/s0168-583x(96)01035-x