Progress of Mid and Far IR Beamlines at Canadian Light Source

Since the 2017 WIRMS at Diamond, the CLS Infrared beamlines have been progressing despite all odds. The year 2018 saw operations cut in half when the ring shut down due to electron gun problems, and most of the first half of 2019 for extended maintenance. Despite this, several improvements occurred. Notable for the Mid IR were installation of a dedicated horizontal ATR microscope interface on the beamline along with an improved PID control on the Active Optics chicane, and enclosure of the Mid IR hutch. A new Agilent spectrometer and Cary 620 microscope with FPA and a new IRSweep QCL IR spectrometer were installed offline. The Far IR most notably hired a new Associate Scientist with a high-pressure science background. The Diamond Anvil Cell microscope had objective/viewing and sample stages motorized and a gas pressure filling station purchased to expand condensed phase work. We installed a new QMC detector and cryostat with closed-cycle helium cooler to good effect. This provides a TES Bolometer for 5-600 cm-1 and a Ge:Cu for 300-1300 cm-1 ranges. A new layout of the Mid IR optics is developing with optics for the Far IR started. This will employ the minimum divergence optics for wide aperture ports of T. Moreno’s design [1,2]. These will apply to both the current and a new ring. An emerging vision of a next-generation ring has motivated work on possible methods for extracting IR from a new ring. A concept is being explored we call “Gentle Bends”. It utilizes a long-radius bending chicane in a straight section of the ring. It can provide a long wavelength source but is complex with multiple edge sources overlapping and extracting the light from the small ring chamber. Many different ring and port parameters need to be determined to see which approach works best for either optics upgrades on the current ring or a future low-emittance lattice ala NSLSII, Soleil, Sirius etc. The Canadian IR Community interest in the new ring has to guide these new developments.

Fig. 1 Concept of new “front end” for the Mid IR beam port. Four added mirrors shape the beam after M1 for minimum divergence. Beam is constrained to go through existing tunnel in shield wall.

[1] T. Moreno, J. Synchrotron Radiation 22, 1163 (2015).
[2] T. Moreno, J. Synchrotron Radiation 24, 386 (2017).

Acknowledgements: Thanks to T. Moreno, R.Oliveira Fritas, L. Dallin and R. Chernikov for good discussions.

Keywords: Synchrotron Infrared Spectroscopy Microspectroscopy