Oak Ridge National Laboratory

Physics Division

Physics Division Seminars

Physics Division Seminars bring us speakers on a variety of physics related subjects. Usually these are held in the Building 6008 large Conference Room, at 3:00 pm on the chosen day, but times and locations may vary. For more information, contact our seminar chairman,

Alfredo Galindo-Uribarri
Tel (Office): (865) 574-6124  (FAX): (865) 574-1268


Thu., August 07, 2014, at 3:00 PM - 4:00 PM (refreshments served at 2:40 PM)

The Isobar Separator for Anions: A Powerful Technique for Suppressing Isobaric Interferences in AMS

Jean-François Alary, Isobarex Corp., Canada
ORNL, Bldg. 6008 Large Conference Room

The Isobar Separator for Anions (ISA) for AMS is an emerging separation technique first applied to the separation of 36S from 36Cl, resulting in the relative suppression of sulphur by six orders of magnitude. Using a radio frequency quadrupole column incorporating gas cells, this innovative technique enables the use of a wide range of low energy ion-molecule reactions and collisional-induced dissociation processes for suppressing specific atomic or molecular anions with a high degree of selectivity. Other elemental pairs (analyte/isobar) successfully separated at AMS level by ISA now include Ca/K, Sr/(Y, Zr), Cs/Ba, Hf/W and Pu/U, potentially enabling the measurement of the radionuclides 41Ca, 90Sr, 135,137Cs, 182Hf, and 236,238Pu at ultra-trace level on smaller accelerators. In view of these initial successes, an effort to develop a version of the ISA that can be used as a robust technique for routine AMS analysis has been undertaken. We will present the detailed layout of a practical ISA and the functional requirements that a combined ISA/AMS system should meet. A pre-commercial ISA system incorporating these concepts is currently being installed at the newly established A. E. Lalonde AMS Laboratory in Ottawa, Canada.

Contact: Alfredo Galindo-Uribarri, (865) 574-6124