[{"@context":"http:\/\/schema.org\/","@type":"BlogPosting","@id":"https:\/\/wiki.edu.vn\/en\/wiki21\/digital-ion-trap-wikipedia\/#BlogPosting","mainEntityOfPage":"https:\/\/wiki.edu.vn\/en\/wiki21\/digital-ion-trap-wikipedia\/","headline":"Digital ion trap – Wikipedia","name":"Digital ion trap – Wikipedia","description":"before-content-x4 Scientific analytical tool A digital ion trap mass spectrometer after-content-x4 The digital ion trap (DIT) is an quadrupole ion","datePublished":"2014-03-10","dateModified":"2014-03-10","author":{"@type":"Person","@id":"https:\/\/wiki.edu.vn\/en\/wiki21\/author\/lordneo\/#Person","name":"lordneo","url":"https:\/\/wiki.edu.vn\/en\/wiki21\/author\/lordneo\/","image":{"@type":"ImageObject","@id":"https:\/\/secure.gravatar.com\/avatar\/c9645c498c9701c88b89b8537773dd7c?s=96&d=mm&r=g","url":"https:\/\/secure.gravatar.com\/avatar\/c9645c498c9701c88b89b8537773dd7c?s=96&d=mm&r=g","height":96,"width":96}},"publisher":{"@type":"Organization","name":"Enzyklop\u00e4die","logo":{"@type":"ImageObject","@id":"https:\/\/wiki.edu.vn\/wiki4\/wp-content\/uploads\/2023\/08\/download.jpg","url":"https:\/\/wiki.edu.vn\/wiki4\/wp-content\/uploads\/2023\/08\/download.jpg","width":600,"height":60}},"image":{"@type":"ImageObject","@id":"https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/b\/b4\/Digital_ion_trap_mass_spectrometer.jpg\/300px-Digital_ion_trap_mass_spectrometer.jpg","url":"https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/b\/b4\/Digital_ion_trap_mass_spectrometer.jpg\/300px-Digital_ion_trap_mass_spectrometer.jpg","height":"237","width":"300"},"url":"https:\/\/wiki.edu.vn\/en\/wiki21\/digital-ion-trap-wikipedia\/","wordCount":20804,"articleBody":"     (adsbygoogle = window.adsbygoogle || []).push({});before-content-x4Scientific analytical tool  A digital ion trap mass spectrometer       (adsbygoogle = window.adsbygoogle || []).push({});after-content-x4The digital ion trap (DIT) is an quadrupole ion trap driven by digital signals, typically in a rectangular waveform, generated by switching rapidly between discrete DC voltage levels. The digital ion trap has been mainly developed as a mass analyzer.       (adsbygoogle = window.adsbygoogle || []).push({});after-content-x4Table of ContentsHistory[edit]The Stability Under the Digital Drive[edit]Secular Frequency and Pseudopotential Well Depth[edit]Instrumentation and Performance[edit]Commercialization[edit]References[edit]History[edit]A digital ion trap (DIT) is an ion trap having a trapping waveform generated by the rapid switching between discrete high-voltage levels. The timing of the high voltage switch is controlled precisely with digital electronic circuitry. Ion motion in a quadrupole ion trap driven by a rectangular wave signal was theoretically studied in 1970s by Sheretov, E.P.[1] and Richards, J.A.[2] Sheretov[3] also implemented the pulsed waveform drive for the quadrupole ion trap working in mass-selective instability mode, although no resonance excitation\/ejection was used. The idea was substantially revisited by Ding L. and Kumashiro S. in 1999,[4][5] where the ion stability in the rectangular wave quadrupole field was mapped in the Mathieu space a–q coordinate system, with the parameters a and q having the same definition as the Mathieu parameters normally used in dealing with sinusoidal RF driven quadrupole field. The secular frequency dependence on the a, q parameters was also derived thus the foundation was laid for many modern ion trap operation modes based on the resonance excitation.[6] Also, in 1999, Peter T.A. Reilly began trapping and subsequently ablating and mass analyzing the product ions from nanoparticles obtained from car exhaust with a primitive hybrid square wave\/sine wave driven 3D ion trap. In 2001 Reilly attended the 49th American Society for Mass Spectrometry (ASMS) Conference on Mass Spectrometry and Applied Topics where he presented his nanoparticle mass analysis work[7][8] and met Li Ding for the first time. Reilly suggested to Ding at that time that they should focus the DIT for analysis in the high mass range where other instruments could not compete. However, work published by Ding and Shimadzu over the years following the 2001 meeting were focused on development of square wave driven DIT’s in the conventional mass range of commercial instrumentation. During this time Reilly began developing digital waveforms to increase the mass range of quadrupole-based mass spectrometers and ion traps that operate with rectangular waveforms.[9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] Over the course of eighteen years, the Reilly group contributed substantially to the development of modern digital waveform technology (DWT), its implementation and characterization, methods of waveform generation,[22][21] and general theory which includes but is not limited to stability diagrams,[18] the pseudopotential model,[19] and more recently digital quadrupole acceptance.[26][27][28][29] In parallel to Reilly’s achievements but also working separately, the Ding group at the Shimadzu Research Lab continued to implement their digital drive technology for a 3D ion trap. Finally, after 18 years Shimadzu unveiled a bench top MALDI square wave driven 3D ion trap mass spectrometer that was designed to work in the higher mass range at the 2019 ASMS conference. The DIT technology has also been developed and implemented in the linear and 3D quadrupole ion traps by many other groups around the world.[30][31][32][33][34][35][36][37][38][39]The Stability Under the Digital Drive[edit]  Fig 1. The drive signal waveform, and the dipole excitation waveform for a digital ion trap (3D)For a 3D type of quadrupole ion trap, ion motion under the influence of a digital waveform (see figure right) can be expressed in terms of the conventional trapping parameters:       (adsbygoogle = window.adsbygoogle || []).push({});after-content-x4az=\u22128eUmr02\u03a92(1){displaystyle a_{z}=-{frac {8eU}{mr_{0}^{2}Omega ^{2}}}qquad qquad (1)!}andqz=4eVmr02\u03a92.(2){displaystyle q_{z}={frac {4eV}{mr_{0}^{2}Omega ^{2}}}.qquad qquad (2)!}  Fig 2. The stability diagram of ion motion in z direction, for 3 different duty cycles of a digital drive waveformHere,  \u03a9 =2\u03c0f is the angular frequency of the digital waveform. Similar definitions of the a,q{displaystyle a,q} for the 2D (linear) ion trap were also given in literature.[40] There are at least two postulates about the nature of the DC component. The first, of which has been attributed to Ding, assumes for the DIT that the DC component, U depends on not only the mid-level of the AC voltages, V1and V2, but also the duty cycle, d of the waveform:U=dV1+(1\u2212d)V2{displaystyle U=dV_{1}+(1-d)V_{2}}Whereas, the second but more general postulate assumes that there is no DC component unless there is an explicit DC voltage offset added to the waveforms. The latter interpretation is explained by the change to the stability diagram that results when the duty cycle moves away from d = 0.5. When this happens the range of stable q and a values for both quadrupole axes change. These changes cause the motion of ions to be more displaced along one axis compared to the other. This, consequently is the effect of the DC bias.It is important to accurately know the stability of ions inside the DIT. For example, different waveform duty cycles result in a different stability boundary. For the case of a square wave, where d = 0.5, the boundary of the first stability region crosses the qz{displaystyle q_{z}} axis at approximately 0.712, which is less than 0.908, the boundary value qz{displaystyle q_{z}} for a sinusoidal waveform. The stability of ion motion in a digitally driven quadrupole can be calculated from the analytical matrix solutions of Hill’s equation:[41][42]"},{"@context":"http:\/\/schema.org\/","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"https:\/\/wiki.edu.vn\/en\/wiki21\/#breadcrumbitem","name":"Enzyklop\u00e4die"}},{"@type":"ListItem","position":2,"item":{"@id":"https:\/\/wiki.edu.vn\/en\/wiki21\/digital-ion-trap-wikipedia\/#breadcrumbitem","name":"Digital ion trap – Wikipedia"}}]}]