The problem for molecular identification knows many solutions, which include mass spectrometers whose mass sensitivity depends on the performance of the detector involved. The purpose of this article is to show by means of molecular dynamics simulations how a laser-cooled ion cloud, confined in a linear radio-frequency trap, can reach the ultimate sensitivity providing the detection of individual charged heavy molecular ions. In our simulations, we model the laser-cooled Ca+ ions as two-level atoms, confined thanks to a set of constant and time oscillating electrical fields. A singly charged molecular ion with a mass of 106 amu is propelled through the ion cloud. The induced change in the fluorescence rate of the latter is used as the detection signal. We show that this signal is due to a significant temperature variation triggered by the Coulomb repulsion and amplified by the radio-frequency heating induced by the trap itself. We identify the optimum initial energy for the molecular ion to be detected, and furthermore, we characterize the performance of the detector for a large range of confinement voltages.
REFERENCES
1.
D. L.
Shinholt
, S. N.
Anthony
, A. W.
Alexander
, B. E.
Draper
, and M. F.
Jarrold
, “A frequency and amplitude scanned quadrupole mass filter for the analysis of high m/z ions
,” Rev. Sci. Instrum.
85
(11
), 113109
(2014
).2.
D. Z.
Keifer
, E. E.
Pierson
, J. A.
Hogan
, G. J.
Bedwell
, P. E.
Prevelige
, and M. F.
Jarrold
, “Charge detection mass spectrometry of bacteriophage P22 procapsid distributions above 20 MDa: CDMS of bacteriophage P22 procapsid distributions above 20 MDa
,” Rapid Commun. Mass Spectrom.
28
(5
), 483
–488
(2014
).3.
K.
Blaum
, “High-accuracy mass spectrometry with stored ions
,” Phys. Rep.
425
(1
), 1
–78
(2006
).4.
M.
Toyoda
, D.
Okumura
, M.
Ishihara
, and I.
Katakuse
, “Multi-turn time-of-flight mass spectrometers with electrostatic sectors
,” J. Mass Spectrom.
38
(11
), 1125
–1142
(2003
).5.
M.
Frank
, S. E.
Labov
, G.
Westmacott
, and W.
Henry Benner
, “Energy-sensitive cryogenic detectors for high-mass biomolecule mass spectrometry
,” Mass Spectrom. Rev.
18
(3-4
), 155
–186
(1999
).6.
N. C.
Contino
, E. E.
Pierson
, D. Z.
Keifer
, and M. F.
Jarrold
, “Charge detection mass spectrometry with resolved charge states
,” J. Ame. Soc. Mass Spectrom.
24
(1
), 101
–108
(2013
).7.
M.
Knoop
, “Detection techniques for trapped ions
,” in Physics with Trapped Charged Particles: Lectures from the Les Houches Winter School
(World Scientific
, 2014
), Chap. 2, pp. 25
–42
.8.
D.
Twerenbold
, D.
Gerber
, D.
Gritti
, Y.
Gonin
, A.
Netuschill
, F.
Rossel
, D.
Schenker
, and J.-L.
Vuilleumier
, “Single molecule detector for mass spectrometry with mass independent detection efficiency
,” Proteomics
1
(1
), 66
–69
(2001
).9.
N.
Takahashi
, S.
Hosokawa
, M.
Saito
, and Y.
Haruyama
, “Measurement of absolute detection efficiencies of a microchannel plate using the charge transfer reaction
,” Phys. Scr.
T144
, 014057
(2011
).10.
I. S.
Gilmore
and M. P.
Seah
, “Ion detection efficiency in SIMS: Dependencies on energy, mass and composition for microchannel plates used in mass spectrometry
,” Int. J. Mass Spectrom.
202
(1
), 217
–229
(2000
).11.
G. W.
Fraser
, “The ion detection efficiency of microchannel plates (MCPS)
,” Int. J. Mass Spectrom.
215
(1
), 13
–30
(2002
), part of Special Issue: Detectors and the Measurement of Mass Spectra.12.
D.
Twerenbold
, J. L.
Vuilleumier
, D.
Gerber
, A.
Tadsen
, B.
van den Brandt
, and P. M.
Gillevet
, “Detection of single macromolecules using a cryogenic particle detector coupled to a biopolymer mass spectrometer
,” Appl. Phys. Lett.
68
(24
), 3503
–3505
(1996
).13.
D.
Twerenbold
, “Cryogenic particle detectors
,” Rep. Prog. Phys.
59
(3
), 349
–426
(1996
).14.
D. Z.
Keifer
and M. F.
Jarrold
, “Single-molecule mass spectrometry
,” Mass Spectrom. Rev.
36
(6
), 715
–733
(2017
).15.
M. A.
Tito
, K.
Tars
, K.
Valegard
, J.
Hajdu
, and C. V.
Robinson
, “Electrospray time-of-flight mass spectrometry of the intact MS2 virus capsid
,” J. Am. Chem. Soc.
122
(14
), 3550
–3551
(2000
).16.
A. R.
Todd
, A. W.
Alexander
, and M. F.
Jarrold
, “Implementation of a charge-sensitive amplifier without a feedback resistor for charge detection mass spectrometry reduces noise and enables detection of individual ions carrying a single charge
,” J. Am. Soc. Mass Spectrom.
31
(1
), 146
–154
(2020
).17.
C.
Champenois
, C.
Dedonder-Lardeux
, C.
Jouvet
, L.
Hilico
, M.
Knoop
, and J.
Pedregosa
, “Non-destructive detection method of charged particles without mass limitation
,” European Patent 14306498, registered on September, 26, 2014.18.
J.
Pedregosa
, C.
Champenois
, M.
Houssin
, and M.
Knoop
, “Anharmonic contributions in real RF linear quadrupole traps
,” Int. J. Mass Spectrom.
290
(2-3
), 100
–105
(2010
).19.
J.
Pedregosa-Gutierrez
, C.
Champenois
, M. R.
Kamsap
, and M.
Knoop
, “Ion transport in macroscopic RF linear traps
,” Int. J. Mass Spectrom.
381-382
, 33
–40
(2015
).20.
N.
Kjærgaard
, L.
Hornekær
, A. M.
Thommesen
, Z.
Videsen
, and M.
Drewsen
, “Isotope selective loading of an ion trap using resonance-enhanced two-photon ionization
,” Appl. Phys. B
71
, 207
–210
(2000
).21.
M.
Knoop
, C.
Champenois
, G.
Hagel
, M.
Houssin
, C.
Lisowski
, M.
Vedel
, and F.
Vedel
, “Metastable level lifetimes from electron-shelving measurements with ion clouds and single ions
,” Eur. Phys. J. D
29
, 163
–171
(2004
).22.
P. F.
Herskind
, A.
Dantan
, M.
Albert
, J. P.
Marler
, and M.
Drewsen
, “Positioning of the rf potential minimum line of a linear Paul trap with micrometer precision
,” J. Phys. B: At., Mol. Opt. Phys.
42
(15
), 154008
(2009
).23.
H. G.
Dehmelt
, “Radiofrequency spectroscopy of stored ions I: Storage
,” Adv. At. Mol. Phys.
3
, 53
–72
(1967
).24.
M.
Drewsen
and A.
Brøner
, “Harmonic linear Paul trap: Stability diagram and effective potentials
,” Phys. Rev. A
62
, 045401
(2000
).25.
A.
Drakoudis
, M.
Söllner
, and G.
Werth
, “Instabilities of ion motion in a linear Paul trap
,” Int. J. Mass Spectrom.
252
(1
), 61
–68
(2006
).26.
L.
Turner
, “Collective effects on equilibria of trapped charged plasmas
,” Phys. Fluids
30
, 3196
(1987
).27.
L.
Hornekær
and M.
Drewsen
, “Formation process of large ion Coulomb crystals in linear Paul traps
,” Phys. Rev. A
66
(1
), 013412
(2002
).28.
C.
Champenois
, “About the dynamics and thermodynamics of trapped ions
,” J. Phys. B: At., Mol. Opt. Phys.
42
(15
), 154002
(2009
).29.
F. G.
Major
, V. N.
Gheorghe
, and G.
Werth
, Charged Particle Traps
, Springer Series on Atomic, Optical, and Plasma Physics Vol. 37 (Springer Berlin Heidelberg
, 2005
).30.
R. D.
Skeel
and J. A.
Izaguirre
, “An impulse integrator for Langevin dynamics
,” Mol. Phys.
100
(24
), 3885
–3891
(2002
).31.
J.
Pedregosa-Gutierrez
and M.
Mukherjee
, “Defect generation and dynamics during quenching in finite size homogeneous ion chains
,” New J. Phys.
22
(7
), 073044
(2020
).32.
M.
Marciante
, C.
Champenois
, A.
Calisti
, J.
Pedregosa-Gutierrez
, and M.
Knoop
, “Ion dynamics in a linear radio-frequency trap with a single cooling laser
,” Phys. Rev. A
82
(3
), 033406
(2010
).33.
See http://www.simion.com for Scientific Instrument Services, Inc., SIMION 8.1.
34.
N.
Sillitoe
, J.-P.
Karr
, J.
Heinrich
, T.
Louvradoux
, A.
Douillet
, and L.
Hilico
, “sympathetic cooling simulations with a variable time step
,” JPS Conf. Proc.
18
, 011014
(2017
).35.
C.
Champenois
, Trapped Charged Particles, Laser Cooling Techniques Applicable to Trapped Ions
(World Scientific
, 2016
), p. 117
.36.
J. D.
Prestage
, A.
Williams
, L.
Maleki
, M. J.
Djomehri
, and E.
Harabetian
, “Dynamics of charged particles in a Paul radio-frequency quadrupole trap
,” Phys. Rev. Lett.
66
(23
), 2964
–2967
(1991
).37.
J. P.
Schiffer
, M.
Drewsen
, J. S.
Hangst
, and L.
Hornekar
, “Temperature, ordering,and equilibrium with time-dependent confining force
,” Proc. Natl. Acad. Sci. U. S. A.
97
, 10697
(2000
).38.
M.
Drewsen
, C.
Brodersen
, L.
Hornekær
, J. S.
Hangst
, and J. P.
Schifffer
, “Large ion crystals in a linear Paul trap
,” Phys. Rev. Lett.
81
(14
), 2878
–2881
(1998
).39.
P. D.
Lett
, W. D.
Phillips
, S. L.
Rolston
, C. E.
Tanner
, R. N.
Watts
, and C. I.
Westbrook
, “Optical molasses
,” J. Opt. Soc. Am. B
6
(11
), 2084
(1989
).40.
R.
Alheit
, C.
Hennig
, R.
Morgenstern
, F.
Vedel
, and G.
Werth
, “Observation of instabilities in a Paul trap with higher-order anharmonicities
,” Appl. Phys. B
61
, 277
–283
(1995
).41.
R.
Alheit
, S.
Kleineidam
, F.
Vedel
, M.
Vedel
, and G.
Werth
, “Higher order non-linear resonances in a Paul trap
,” Int. J. Mass Spectrom. Ion Processes
154
, 155
–169
(1996
).42.
V. L.
Ryjkov
, X. Z.
Zhao
, and H. A.
Schuessler
, “Simulations of the rf heating rates in a linear quadrupole ion trap
,” Phys. Rev. A
71
(3
), 033414
(2005
).43.
J. D.
Tarnas
, Y. S.
Nam
, and R.
Blümel
, “Universal heating curve of damped Coulomb plasmas in a Paul trap
,” Phys. Rev. A
88
(4
), 041401
(2013
).44.
G.
Zwicknagel
, C.
Toepffer
, and P.-G.
Reinhard
, “Stopping of heavy ions in plasmas at strong coupling
,” Phys. Rep.
309
(3
), 117
–208
(1999
).45.
M.
Bussmann
, U.
Schramm
, and D.
Habs
, “Simulating the stopping dynamics of highly charged ions in an ultra-cold, strongly coupled plasma
,” Hyperfine Interact.
173
(1-3
), 27
–34
(2006
).46.
A.
Poindron
et al. “Heating of Coulomb crystals in linear RF traps
,” (to be published) (2021
).© 2021 Author(s).
2021
Author(s)
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