An overview on TRIUMF’s developments on ion source for radioactive beams (invited)

Abstract

The ISAC facility at TRIUMF utilizes up to 100 microA from the 500 MeV H(-) cyclotron to produce the radioactive ion beam (RIB) using the isotopic separation on line method. The ISAC-I facility comprised the RIB production target stations, the mass separator, and the beam delivery to low energy area and to a room temperature linear accelerator composed of a four-rod radio frequency quadrupole and an interdigital H-type structure drift tube LINAC. ISAC-I linear accelerator can provide beam from A=3 to 30 amu with an energy range from 0.15 to 1.5 A MeV. Since the beginning of operations target development program has been to increase proton beam currents on targets. Now we routinely operate our target at 50-85 microA and recently we have operated our target at 100 microA. Other developments are in place to add other ion sources, laser, force electron beam induced are discharge and electron cyclotron resonance ion source to the actual surface ion source. The last two five year plans were mainly devoted to the construction of a heavy ion superconducting LINAC (ISAC-II) that will upgrade the mass and the energy range from 30 to 150 and from 1.5 to 6.5 A MeV, respectively. The intermediate stage E< or =4.2 A MeV is already completed and commissioned; three experiments using (11)Li, (9)Li, and (29)Na have been completed this summer.

First Direct Mass Measurement of the Two-Neutron Halo NucleusHe6and Improved Mass for the Four-Neutron HaloHe8

“…The beam was ionized using the Forced Electron Beam Ion Arc Discharge (FEBIAD) source [19] and transported at an energy of 20 keV to the TITAN facility. Contamination in both beams was removed using a two-stage high resolving power dipolemagnet mass separator.…”

Atomic physics techniques for studying nuclear ground state properties, fundamental interactions and symmetries: status and perspectives

“…More than 20 years after the first (off-line) in-source laser spectroscopy on radioisotopes by the Letokhov group [71] in Troitzk and the proposal to use it at ISOL facilities [72], ion sources based on resonance ionization spectroscopy are now very common at ISOL facilities and are used, for example at ISOLDE in more than 50% of the beam times. With the exception of Oak Ridge National Laboratory [73,74], all other ISOL facilities using laser ion sources were represented at LASER 2009 in Poznan and the following reports on the status and further development work were given: Bruce Marsh and Anna Sjödin [75] for ISOLDE at CERN, Jens Lassen [76] for ISAC at TRIUMF, Mikael Reponen and Iain Moore [77][78][79] for IGISOL at Jyväskylä and Yuri Kudryavtsev [80,81] for LISOL at Louvain-la-Neuve.…”

“…Another solution called laser ion source trap (LIST), a combination of a laser ion source with an ion trap, was proposed by Blaum et al [89] quite some time ago. In the meantime development work at Jyväskylä [90], Louvain-La-Neuve [91], Mainz [83,92], and TRIUMF [76] was performed. A breakthrough was achieved by the Leuven group as mentioned above by the experiments on Cu isotopes at the LISOL facility in Louvain-La-Neuve [44], where a combination of an IGISOL gas cell and a linear sextupole radiofrequency trap was shown to suppress the isobaric background very effectively.…”

Development of the collinear laser beam line at TRIUMF

“…20 F development was carried out on the metastable atomic state of the stable isotope 19 F, and the results extrapolated to 20 F. The results showed that a 20 F beam polarization of ∼15% should be achievable. A FEBIAD (forced electron beam induced arc discharge) on-line ion source [14] which can produce a 20 F + beam has since been installed, making possible the future measurement of the alignment term of 20 F.…”