The Measurement ofeMby Cyclotron Resonance

Abstract

The cyclotron resonance frequency of the proton has been measured using a new method. By measuring the spin precessional frequency of tie proton in the same magnetic field, the proton magnetic moment in nuclear magnetons has been determined as Mp=2.79276=k0.00006. In combination with other data this result can be used directly to determine the charge-to-mass ratio of the proton e/ilf p =9579.4 2 db0.3 emu/g, the faraday F=9652.0 3 ±0.3 emu/g (physical scale), and the ratio of the proton mass to the electron mass M p /w e =1836.12±0.05. A preliminary value for the H 2 -D doublet is given. Goudsmit, Phys. Rev. 74, 622 (1948). 2 J. A. Hippie and H.

Distance-of-Flight Mass Spectrometry: What, Why, and How?

“…Just as the scope of MS applications is broad, so are the types of mass spectrometers. If we consider just mass analyzers-not in combination with the numerous varieties of ion sources or in connection with separations methods or in combination in MS/MS instruments-we are still left with a long list (acronyms in order of invention): TOFMS 1 [18], SFMS 2 [19], FTICR-MS 3 [20,21], Q-MS 4 [22,23], QIT-MS 5 [22,23], QqQ-MS 6 [24][25][26][27], Orbitrap [28], and DOFMS 7 [29]. Consequently, the question of what distinguishes one mass-analysis approach from another is pivotal and nontrivial; in this regard, many authors have attempted to define and categorize mass analyzers according to performance characteristics and basis of operation [17,[30][31][32].…”

High Resolution Mass Spectrometry Using FTICR and Orbitrap Instruments

“…(Vartanian, Anderson et al 1995) In the 1950s the principle of ion cyclotron resonance was first incorporated into a mass spectrometer, called the omegatron, by Sommer and co-workers, who successfully applied the concept of cyclotron resonance to determine the charge-tomass ratio of the proton. (Sommer, Thomas et al 1951) Major improvements in ICR awaited McIver's introduction of the trapped ion cell. Unlike the conventional drift cell, the trapped ion cell allowed for ion formation, manipulation and detection to occur within the same volume in space.…”

“…The principles of time-of-flight (TOF) and ion cyclotron resonance (ICR) were introduced in 1946 and 1949, respectively. (Sommer, Thomas et al 1951;Wolff and Stephens 1953) Applications to organic chemistry started to appear in the 1950s and exploded during the 1960s and 1970s. Double-focusing high-resolution mass spectrometers, which became available in the early 1950s, paved the way for accurate mass measurements.…”

Raman spectroscopic and mass spectrometric investigations of the hydrogen isotopes and isotopically labelled methane

“…The physical basis of the mass separation in the Omegatron is the ionic cyclotron resonance frequency [26]. The orbital fiequency o of an ion with mass m and elemenw charge e in a homogeneous magnetic field of strength B is independent of thermal motion and is given by:…”