Population memory length

As a result, the atomic state populations as well as the polarization in the atomic flux departing from the surface are different from those in the flux arriving at it. This distinction carries information on the relaxation processes in the close vicinity of the surface. It is reasonable to introduce "memory lengths" which determine the characteristic distances at which this information is still contained in the departing flux. Then the population memory length can be defined as l = VjT, whereas the polarization memory length h = VjTi (Bordo and Rubahn 2004). 

Problem 7.3. The fluorescence spectrum will be sensitive to the population of the scattered atoms if the evanescent wave penetration depth, S, is less than, or comparable to, the population memory length Ip (see Section 2.4.3). This condition is fulfilled at incidence angles above 0, satisfying the equation... 

Memory dysfunction has been a frequent complaint in populations of workers exposed to various neurotoxicants and is tapped by several different tests used in a human testing context. One of the most widely used for this purpose is the digit span that constitutes one of the WAIS subtests. As indicated earlier, this test requires the subject to recall a series of digits, and the length of the list is successively increased contingent upon the subject correctly recalling the members of the list. In some cases, words or letters are utilized instead of digits. As is the case with experimental animal studies, more complex versions of these tests have been devised and... 

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