Measurement of small photodestruction rates of cold, charged biomolecules in an ion trap

Abstract

In this work, we demonstrate quantitative measurements of photodestruction rates of translationally cold, charged biomolecules. The long-term stable storage of the molecular ions in an ion trap under ultra-high vacuum conditions allows measurement of small rates and verification that rates are linear in photodestruction laser intensity. Measurements were performed on singly protonated molecules of the organic compound glycyrrhetinic acid (C30H46O4), dissociated by a continuous-wave UV laser (266 nm) using different intensities. The molecules were sympathetically cooled by simultaneously trapped laser-cooled barium ions to translational temperatures of below 150 mK. Destruction rates of less than 0.05 s−1 and a cross section of (1.1 ± 0.1) × 10−17 cm2 have been determined. An extension to tunable UV laser sources would permit high-resolution dissociation spectroscopic studies on a wide variety of cold complex molecules.

An integrated ion trap and time-of-flight mass spectrometer for chemical and photo- reaction dynamics studies

“…16,17 While the LQT is a thoroughly proven device, direct identification of non-fluorescing ions in a LQT is not straightforward and is often problematic. Current methods to identify ions in a LQT include nondestructive resonant-excitation mass spectrometry using laser-induced fluorescence detection, 18,19 destructive resonant-excitation mass spectrometry using channel electron multiplier (CEM) detection, [20][21][22] LQT mass-filtering techniques, 22,23 and molecular dynamics (MD) simulations. 24,25 The first three methods are complicated by LQT properties which give rise to nonlinear resonances, multiple secular frequencies, and trap-depth limitations.…”

Molecular cooling via Sisyphus processes

“…RF [99, 100] 85,87 Rb 2 [101-103], Cs 2 [104], 40 K 2 [105], Li 2 [106-108], Na 2 [109], 40 KRb [110], 41 K 87 Rb [111], Cr 2 [112], Li 3 [113], NaK [114] Cs 2 [116], H 2 [117], Rb 2 [118], Li 2 [119], Na 2 [120], K 2 [121-123], He * CO [151], ND 3 [173], D 2 O [174], CH 3 F [175], CF 3 H [176], CH 3 CN [177], H 2 O , D 2 O, HDO [178], NH 3 , CH 3 I, C 6 H 5 CN, C 6 H 5 Cl [179] BeH + , YbH + [183], AF350 + =C 16 H 14 N 2 O 9 S + [184], MgH + [1], O + 2 , MgO + , CaO + [185], H + 2 , H + 3 [186], BaO + [187], NeH + , N + 2 , OH + , H 2 O + , HO + 2 , ArH + , CO + 2 , KrH + , C 4 F + 8 , R6G + [182], Cyt 12+ , Cyt 17+ [188] GAH + =C 30 H 46 O 4[189] …”

Detection of single-ion spectra by Coulomb-crystal heating

“…Sympathetic cooling brings the motion of all trapped ions to the equilibrium temperature of the laser-cooled ions [9] in a time proportional to the secular frequency of the trap [10,11]. Controlled ensembles of cold atomic and molecular ions have the potential for many applications, including quantum information processing [12,13], ultra-high-resolution spectroscopy [13][14][15][16][17], optical clocks [18,19], nano deposition of dopant atoms in semiconductors [20], and studies of molecular properties and chemical reactions [21][22][23][24][25][26][27][28][29][30][31].…”