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Laser polarizer & collinear laser spectroscopy facility

The laser polarizer facility (Polarizer), produces ion beams which are highly nuclearspin polarized, up to 80% or more in some cases. This is accomplished using laser interaction with the incoming beam. The outer electron of each atom passing through counter-propagating laser light repeatedly absorbs and emits photons, indirectly affecting the nucleus as well via the magnetic interaction between the electron and the nucleus. In our case, the angular momentum of circularly polarized light is transferred to the nuclei. Thus a beam with high nuclear polarization becomes available as an analytical tool. The polarizer facility, consisting of a continuous-wave, narrow-bandwidth laser system and the polarizer beam line, was built and is operated under TRIUMF research scientist Dr. Philip Levy. The main usage of the Polarizer has been to provide polarized 8Li for condensed matter studies using beta-detected nuclear magnetic resonance (βNMR) and nuclear quadrupole resonance (βNQR), but it also provides polarized beams for tests of fundamental symmetries and in nuclear structure studies. In the latter category there is overlap with the Laser Spectroscopy group, who conduct collinear fast beam laser spectroscopy (CFBS) experiments using the polarizer facility to determine nuclear moments via precision optical isotope shift and hyperfine structure measurements.

History: the polarizer facility was pioneered by Dr. Levy (ret.) who helped develop and operated the optically pumped polarized H- ion source (OPPIS), which allowed the TRIUMF cyclotron to provide polarized proton beams to high precision experiments. Although the polarized proton program at TRIUMF ended in 2000, OPPIS lives on as the polarized source at Brookhaven National Lab Polarizer laser lab Polarizer beam line Be.

Since 2020 the polarizer is under Dr. Ruohong Li who seeks to expand the range of nuclear spin polarized probes for the ISAC experimental programs and develop these beams to an expanded number of user end stations. To develop optical pumping schemes for isotopes their atomic fine structures and hyperfine structure splittings must be known - and often measured using collinear fast beam laser spectroscopy in the polarizer facility. 

Current developments are towards the implementation of nuclear spin polarized beams of a variety of elements to serve existing and new research programs in the life sciences, to achieve highes efficiency in operation and swtich-over between (i) different polarized beams, (ii) colinear fast beam laser spectroscopy experiments and (iii) different b-NMR experiments at new experimental stations.

In the ARIEL era the polarized beams program will see a significant increase in beam hours and move towards multi-species beam delivery program. 

lithium

for beta-NMR, beta-NQR & particle physics

11 beryllium

for sensitive asymmetry detection needed

31,33 magnesium

for b-NMR, nuclear decay spectroscopy

actinium

for bio beta-NMR, RadMol 

 copper

for polarized beams 

2nd gen. collinear laser spectroscopy (CLS)

and polarizer setup upgrades for new polarized beams for nuclear physics and materials sciences & collinear resonance ionization spectroscopy

laser system upgrades for multi-beam development

(2nd Coherent 899-21 ring-dye laser system (2022), Matisse-CS TiSa ring laser system (2023) lasing also at 671nm (Li wevelength), wavetrain cw-frequency doubler for TiSa laser (2024)

develop next gen. polarizer (POLARIS) for multi element spin polarized beam delivery 

CFI funding applied for two all-solid state laser systems to cover dye & TiSa laser wavelength ranges in addition to frequency doubling and sum-frequency generation

Dr. Ruohong Li (Laser Physicist)

post doc (to be filled)

PhD/MSc student (Katarina Preocanin & to be filled)

alumni

 

Aryan Prasad (2023), U Waterloo B EEng, now U Toronto BSc

Pratham Kulkarni (2023) MITACS IIT Guwahati 

 

Runa Yasuda, PhD TUAT (2023)

Mathias Roman U Ottawa (2022) 

Phil Levy 2010 - laser lab
Dr. Phil Levy (Senior Scientist, ret.)

Dr. SeongGi Jo, IBS-RAON user group & ChungAn U (Seoul)

EunKang Kim (2019) Ph.D. student Korean National U of Education, now U Mainz-GSI