IP determination and 1+1 REMPI spectrum of SiO at 210–220 nm in an ion trap: Implications for SiO+ ion trap loading

The 1+1 REMPI spectrum of SiO in the 210–220 nm range was recorded. Observed bands were mostly assigned to the vibrational bands v ″ = 0 - 3 , v ′ = 5 - 10 of the A - X electronic transition. Additionally, a band near 216–217 nm was tentatively assigned as a 2-photon transition from X to the n = 12 , 13 [ X 2 Σ + , v + = 1 ] Rydberg states. Based on observed lines we estimated the IP of SiO to be 11.594(5) eV. The SiO+ cation has previously been identified as having a cycling transition useful for state control by optical pumping. Our work allowed us to identify an efficient method for loading an ion trap with rotationally and vibrationally cold SiO+ from an ablated sample of SiO by photoionizing through the (5,0) A - X band at 213.977 nm.