Charge-to-mass ratio for electron

Anomalous electron moment correction Atomic mass unit Avogadro constant Bohr magneton Bohr radius Boltzmann constant Charge-to-mass ratio for electron Compton wavelength of electron... 

J. J. Thomson Plum pudding model charge-to-mass ratio of electron Work with cathode rays discovered the positive and negative nature of the atom also determined the charge-to-mass ratio for electrons... 

Measured the charge-to-mass ratio for a beam of electrons... 

From Equation 1.10 the charge-to-mass ratio for the electron could be determined from quantities read directly off Thomson s apparatus. The currently accepted value is elm = 1.7588202 X 10 C kg, where charge is measured in coulombs and mass in kilograms. (See Appendix B for a full discussion of units of measure.)... 

Once the charge-to-mass ratio for the electron had been determined, additional experiments were necessary to determine the value of either its mass or its charge, so that the other could be calculated. In 1909, Robert Millikan (1868-1953) solved this dilemma with the famous oil-drop experiment, in which he determined the charge of the electron. This experiment is described in Figure 5-2. All of the charges measured by Millikan turned... 

The charge and mass of an electron are often denoted by the letters e and m, respectively. In 1897, J. J. Thomson calculated the e/m ratio for an electron, and for this he was awarded a Nobel prize in 1905. In this activity, you will follow in Thomson s footsteps and determine the charge to mass ratio of an electron. 

What is the equation for the charge to mass ratio (e/m) in terms of the voltage (V), current (/), constant (k), electron travel radius (r), coil radius (R), and number of coil turns (/V) Use this equation and the fact that the e/m ratio will be a constant to answer questions 2-4. 

Walter Kanfmarm also reported the determination of the charge-to-mass ratio of cathode rays (abont 10 emu g- ) in a paper he submitted in April 1897 (7). Kanfmarm also based his result on magnetic deflection measurements however, he concluded that the hypothesis of cathode rays as emitted particles could not explain his data. (One of the outstanding questions in the study of cathode rays in the late 1890s was whether they were particles or electromagnetic waves. Thomson and Kanfmarm were typical of their coimtrymen most British researchers leaned toward the particulate hypothesis and most Germans toward waves.) Today Kanfmarm is better known for his careful measurements of the velocity-dependent mass of the electron published over several years beginning in 1901 these results were later explained by special relativity. 

The stationary sedimentation velocity of a particle is an experimentally accessible quantity for some systems, so item 4 summarizes much of our interest in sedimentation. Unfortunately, it is the ratio (m/f) rather than m alone that is obtained from sedimentation velocity in the general case of particles of unspecified geometry. The situation is comparable to the result of the classical experiment of J. J. Thomson in which the charge-to-mass ratio of the electron was determined. 

The determination of the g factor thus requires a measurement of the Larmor and the cyclotron frequency. The electrons cyclotron frequency may conveniently be replaced by w /u> x w, where uj, is the ions cyclotron frequency. This is of advantage because the cyclotron frequency of the ion and the Larmor precession frequency can measured at the same particle. The ratio ujec/ujlc is the charge to mass ratio of the ion to the electron. For the case of Carbon it has been determined in Penning trap experiments by van Dyck and coworkers [16],... 

CPT invariance is a fundamental property of quantum field theories in flat space-time which results from the basic requirements of locality, Lorentz invariance and unitarity [1,2,3,4,5]. A number of experiments have tested some of these predictions with impressive accuracy [6], e.g. with a precision of 10-12 for the difference between the moduli of the magnetic moment of the positron and the electron [7] and of 10-9 for the difference between the proton and antiproton charge-to-mass ratio [8],... 

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