The RFQ LIS is a version of the resonant ionization laser ion source, that tries to eliminate the hot transfer tube from the target to the ion extraction optics. As this transfer tube is alternatively used as a surface ion source it not only serves to collimate and re-focus the reaction products escaping the target, but it also serves as a source of surface ions.
These residual surface ions lead to isobaric contamination to the laser ionized beam. The TRIUMF RFQ-LIS uses a cold radio-frequency ion guide to connect the target to the ion extraction region.
Dedicated development and transfer to on-line operation will be carried by Dr. S. Raeder (Ph.D. Mainz U. 2011) with the goal of a first on-line test in 2013.
Current status: successful on-line test on SiC#28 target with 40microA p+ on target.
Performance: (i) 106 suppression of Na isobars in suppression mode (ii) 50 x intensity decrease of wanted isotope over conventional RILIS.
-> successful experimental run of the TITAN Penning trap mass spectrometer on 20,21Mg and 24Al.
Next test: IG-LIS with UC target (November 2013)
IG-LIS (ion guide laser ion source) development:
Dr. J. P. Lavoie
Dissertation on off-line prototype RFQ-LIS with segmented electrodes.(Ph.D. U.Laval 2010)
proof of principle at LIS TESTSTAND
Dr. S. Raeder
(since July 2011) task of prototype optimization, transfer to on-line operation & initial on-line operation.
(2012) off-line tests & comparison between IG and segmented IG LIS
(spring 2013) successful on-line run on Al & Mg isotopes (TITAN Penning trap mass measurements on 20,21Mg, 24Al)
Thesis "development of a radio frequency quadrupole laser ion source (RFQ-LIS) for isobar suppression"
(M.Sc. TU Darmstadt 2013)
(RILIS research assistant 2013-2016)