Description
Collinear laser spectroscopy coupled with optical pumping, within the cooler-buncher, has proved a highly successful technique at IGISOL-4 (and at the previous IGISOL-3) [1-3] and has facilitated spectroscopy on manganese, niobium, yttrium and even the doubly charged yttrium ion. The technique is however critically limited by conditions within the cooler-buncher. The pumping, while highly efficient and well matched to our pulsed laser system, is subject to the Doppler and pressure perturbations and collisional relaxation encountered within the gas-filled device. These limitations have motivated the development of a secondary electrostatic trap, which operates in vacuum, and resulted in the development of the Manchester ConeTrap.
The ConeTrap, pioneered by Schmidt et al. [4], is a readily constructed, electrostatic device that is especially suitable for deployment at the IGISOL [5]. The devices have been shown to successfully contain close to 105 ions for time periods in excess of 100 ms (many times the atomic excitation and de-excitation lifetimes) and are well matched to the typical ion plumes released from the IGISOL cooler-buncher (typically 1-10k ions released in an ensemble of less than 10 microsecond duration). With limited, but critical, modification to the original design a trap suitable for use on the cooler-buncher platform was constructed and deployed at the IGISOL.
While successfully demonstrating the device was operational, the initial tests showed that only a physically larger trap with matched injection and extraction ion optics would provide the desired spectroscopic performance. Such a trap has now been developed on a bespoke testbed (in Manchester) and will shortly be (re-)deployed at the IGISOL. The new design, development, simulation and commissioning of the device along with future spectroscopic opportunities will be presented.
[1] B. Cheal et al., Phys. Rev. Lett. 102, 222501 (2009)
[2] F. Charlwood et al., Physics Letters B, 690(4), 346-351 (2010)
[3] L. J. Vormawah et al., Phys. Rev. A 97, 042504 (2018)
[4] H. T. Schmidt et al., Nucl. Instr. and Methods B, 173 523-527 (2001), P. Reinhed et al., Nucl. Instr. and Methods A, 621 83–90 (2010)
[5] S. Kelly et al., Hyperfine Interact. 238, 42 (2017)
