[Triumf-seminars] TRIUMF ISAC Seminar today at 15:15

Mon, 8 May 2006 05:00:05 -0700

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Date/Time: Mon 2006-05-08 at 15:15

Location:  Auditorium          

Speaker:   Sami Rinta-Antila (University of Jyväskylä)

Title:     High Precision Mass Spectrometry and Trap Assisted Spectroscopy at JYFLTRAP

Abstract: JYFLTRAP triple trap system is fed by Ion Guide Isotope Separator On-Line (IGISOL) at the Department of Physics, University of Jyväskylä. The trap system is designed to serve various spectroscopic experiments as well as precision mass measurements. Its first component, the buffer gas filled radio frequency quadrupole cooler and buncher, converts IGISOL dc beam with high energy spread and emittance into ion pulses with low energy spread and reduced emittance. These ion bunches can be then sent either to collinear laser spectroscopy line or to the second stage of the JYFLTRAP system, the purification trap. Purification trap is a buffer gas filled Penning trap situated inside warm bore of 7 T superconducting solenoid. In the purification trap mass selective cooling is used to filter, with resolving power of 10^4 – 10^6, the wanted ion species to further transport them either to precision trap inside the same magnet or through the second trap into a spectroscopy setup at the end of extraction beam line. With the precision trap mass measurements up to precision (delta-m/m) of 10^-8 are done using time-of-flight (TOF) technique. 

      So far about 100 masses of refractory fission fragments are measured with typical uncertainty less than 10 keV. High precision work has concentrated on Q-value measurements to study weak interaction via superallowed beta-decays of 26mAl, 42Sc, 46V and 62Ga where Q_EC values with sub-keV precision are reached. 

      Trap assisted nuclear spectroscopy at JYFLTRAP can be divided into two: spectroscopy with purified beams and in-trap spectroscopy. Spectroscopy with purified beams uses the purification trap as a high resolving power separator letting the selected single isobar through to detection setup. This technique was used to study 100, 102 and 104Zr beta decays. 

      In-trap spectroscopy refers to a detection of radiation emitted in the decays of radioactive ions held in the trap. This kind of spectroscopy was tested at JYFLTRAP in on-line experiment where we detected conversion electrons de-exciting isomeric states with small Si detector placed at the extraction end of trap electrode structure. For example from decay of excited isomeric state of 117Pd with 19.1 ms half life a conversion electron cascade could be detected. 

      In this talk I will first introduce JYFLTRAP apparatus and show some of its applications and results then I will concentrate more on trap assisted spectroscopy.  

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