Principles of Ion Traps

Accurate modelling of small-scale linear ion trap operating mode using He buffer gas to improve sensitivity and resolution for in-the-field mass spectrometry

“…The number of confined ions starts to increase from p G = 1×10 −5 torr, then tends to stabilise to 0.66 from p G = 1 × 10 −3 torr. The same shape of variation in the number of ions has been observed in experiments, for instance, to fill up a 3D Paul trap of 1 cm 3 volume when ions are injected along the axial direction (see Figure 17 in Page 52 of Reference 20 ) and to accumulate ions in a linear radiofrequency trap of the ISOLTRAP mass spectrometer (see…”

The physics and applications of strongly coupled plasmas levitated in electrodynamic traps

“…According to the Earnshaw theorem a static electric field cannot achieve 3D binding [8,9,10]. In order to overcome this problem two main types of traps have been developed: (1) the Penning trap, which employs a static electric field to achieve axial confinement and a superimposed static magnetic field that provides radial confinement, and (2) the Paul or RF trap, which relies on an oscillating, inhomogeneous electric field [12,47] that creates a dynamic pseudopotential. A sketch of a quadrupole ion trap (QIT) is shown in Fig.…”

“…An adequately chosen amplitude and frequency Ω of the oscillating RF field ensures trapping of charged particles of mass m and charge q in all three dimensions, by means of a ponderomotive force oriented towards the trap centre. The 3D Paul trap provides a confining force with respect to a single point in space called the node of the RF field, which recommends its use for single ion experiments or for the levitation of 3D crystalline ion structures [12].…”

“…Another ion trap pioneer is H. Dehmelt whose contributions are mainly linked to the development and use of the Penning trap [11,12,13]. He invented ingenious methods of cooling, perturbing, trapping (one single electron was trapped for more than 10 months [14,15]), and probing the trapped particles, thus forcing them to reveal their intrinsic properties [16].…”

From Single Atoms to Engineered “Super-Atoms”: Interfacing Photons and Atoms in Free Space

“…This effectively creates a 3D static conservative potential for an ion. The idea behind a Paul ion trap is to use metal electrodes and apply the corresponding time varying voltages to them to create the configuration of electric charges, that is necessary for ion trapping [50]. The depth of a Paul trap for single atomic ions can be orders of magnitude larger than a room temperature, so it can trap even a thermal ion (we use a temperature conversion from the trap depth Paul = Paul / with being the Boltzmann constant).…”