First-Doppler effect

In this section, the relationship between the measured quantity and the desired center-of-mass differential cross-section will be established and a brief description of the data analysis procedure will then be given. First, consider a Newton sphere with a single value of the product velocity v (see Fig. 4). From the Doppler-shift formula, at a given laser wavelength, the Doppler effect selectively ionizes those ions with vz = vcosO in the... 

In order to dissipate the recoil energy Mossbauer was the first to use atoms in solid crystal lattices as emitters and also to cool both emitter and absorber. In this way it could be shown that the 7-ray emission from radioactive cobalt metal was absorbed by metallic iron. However, it was also found that if the iron sample were in any other chemical state, the different chemical surroundings of the iron nucleus produce a sufficient effect on the nuclear energy levels for absorption no longer to occur. To enable a search for the precisely required absorption frequency, a scan based on the Doppler effect was developed. It was noted that a velocity of 102 ms-1 produced an enormous Doppler shift and using the same equation (7) it follows that a readily attainable displacement of the source at a velocity of 1 cms-1 produces a shift of 108 Hz. This shift corresponds to about 100 line-widths and provides a reasonable scan width. 

Doppler Effect (or Principle) and Its Application for Military Purposes. The Doppler (or more correctly Doppler) effect, first observed by C.J. D oppler of Prague in 1842, involves the apparent change in the frequency of light, sound, or electromagnetic waves observed while the source and the observation point are in motion relative to each other. The effect is commonly ob-... 

When a spherical particle enters the crossing volume of two laser beams, a Doppler effect occurs not only in frequency shift but also in phase shift of the scattered light. The frequency shift yields the velocity of the sphere, whereas the phase shift gives the particle size. The phase Doppler principle has been employed to measure the size and size distributions of spheres in addition to the particle velocity. The phase Doppler principle was first reported by Durst and Zare (1975) and became a viable measurement tool one decade later [Bachalo and Houser, 1984]. 

Shortly after the Cosmic Microwave Background (CMB) was discovered, the first anisotropy in the CMB was seen the dipole pattern due to the motion of the observer relative to the rest of the Universe (Conklin, 1969). After confirmation by Henry, 1971 and by Corey and Wilkinson, 1976 the fourth discovery of the dipole (Smoot et al., 1977) showed a very definite cosine pattern as expected for a Doppler effect, and placed an upper limit on any further variations in Tcmb Further improvements in the measurement of the dipole anisotropy were made by the Differential Microwave Radiometers (DMR) experiment on COBE (Bennett et al., 1996 and by the Wilkinson Microwave... 

Resonance gamma spectrometry or Mossbauer spectrometry can be used to study the hyperfine interactions between a nucleus and its chemical neighborhood [142], In order to examine these interactions with the help of a Mossbauer spectrometer, the first-order Doppler effect shift of the wave emitted by a moving source is applied. The arrangement used for a Mossbauer spectrometer consists of a radioactive source containing a Mossbauer isotope in an excited state (see Figure 4.54)... 

These three fluctuating effects, with their respective orders of magnitude, account for the observed standard deviation 6xi0-9 ( 2.5 kHz), which therefore represents the effective uncertainty on our measurement. Residual first order Doppler effect and relativistic corrections are negligible at this scale. 

The first part of the energy Eq(x, p) is the kinetic energy Kin(p) = p2 / 2 M. For the matter-field interaction, this energy produces the well-known Doppler effect of inhomogeneous broadening of optical transitions. The second part is the interaction with electrodes, i.e. the Lennard-Jones potential near the equilibrium point xq = 0 taken in the harmonic approximation as Upot(x) = M O2 r 2/2. The third part is the electrostatic interaction of the dot electron in... 

I here are four sources of line broadening (I) (he uncertainty eCfecl> (2) the Doppler effect. (. ) pressure effects due to collisions between atoms of the same kind and with foreign atoms, and (4) electric and magnetic field effects. We consider only the first three of these phenomena here. The magnetic field effect will be discussed in Section 9C -I in connection with the /eeman effect. 

Two factors contribute to AE band broadening. The first is due to the motion of M atoms in the plasma, a so-called Doppler effect and the second is broadening due to collisions. Doppler broadening, symbolized by AXj), depends on the wavelength chosen, the kinetic temperature and the molecular weight of the metal of interest and can be predicted as follows (109) ... 

The first method, which was that used by Moon, who first detected the effect, made use of a Au source electroplated on to the periphery of a mechanical rotor. The details of both first and second methods have been summarized by Malmfors [i9]. The lifetime of the state can be calculated from the measured cross section for the process, the y-ray energy, and from the Doppler effect. It is instructive to compare the lifetimes obtained by different methods. The lifetime of the 411 kev state of Hg found by Graham and Bell by the method of delayed coincidences was (1.0 0.7) X10" sec that found by Moon and Davey by mechanical motion was (2.2 0.5) X10" sec by Malmfors (by heating), 3.5 X 10 sec and by Metzger and Todd , (2.2 0.2) X10 sec. In the same way, the lifetime of the 209 kev state of Hg found by Metzger and Todd ,... 

French physicist. In 1845 he and L on Foucault (1819-68) took the first photographs of the sun. In 1849 he measured the speed of light (see Fizeau s method) he also analysed the Doppler effect for light. 

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