| 1 | By R.P.Kokoulin, May 12th, 2000 |
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| 2 | |
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| 3 | Multiple Coulomb Scattering some questions and problems |
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| 4 | |
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| 5 | Apart from the problems of creation and development of convenient |
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| 6 | procedure for fast simulation of the effect, some principal questions are to be |
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| 7 | answered (possibly, most of them have already been investigated) |
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| 8 | |
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| 9 | General |
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| 10 | |
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| 11 | Is it possible to use cross section formulae without magnetic formfactor and spin effects: |
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| 12 | |
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| 13 | a) for nucleus (probably yes); |
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| 14 | b) for proton (possibly yes); |
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| 15 | c) for electron (probably no). |
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| 16 | |
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| 17 | Should the scattering on the screened nucleus and on atomic electrons be considered |
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| 18 | separately? (likely, they should; they probably can be combined later, but
) |
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| 19 | |
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| 20 | Scattering on the nucleus: |
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| 21 | |
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| 22 | a) influence of the choice of the elastic atomic formfactor (TF, HF, hydrogen-like,
); |
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| 23 | there is a hope that the difference is small (with a proper choice of the parameters) but |
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| 24 | it should be estimated; |
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| 25 | b) influence of the nuclear size (it should influence RMS angle and distribution shape on |
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| 26 | the tail); |
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| 27 | c) influence of the choice of nuclear formfactor (exponential, Gaussian, Fermi model, |
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| 28 | etc.); probably, it is small (only RMS nucleus radius is crucial) but it is better to |
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| 29 | compare directly; |
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| 30 | d) contribution of inelastic nucleus formfactor (incoherent scattering on protons of the |
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| 31 | nucleus); |
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| 32 | e) necessity of taking into account proton formfactor (for incoherent scattering); last two |
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| 33 | points are expected to give small effect but need evaluation. |
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| 34 | |
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| 35 | Scattering on atomic electrons: |
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| 36 | |
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| 37 | a) introduction and influence of the choice of inelastic atomic formfactor (TH, |
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| 38 | hydrogen-like exponential, what else?) it should be evaluated; more simple |
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| 39 | approaches, such as Z(Z+1) substitutions, seem to be incorrect; |
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| 40 | b) problem of a double account for scattering on electrons if explicit simulation of the |
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| 41 | elastic scattering of the projectile on electrons (possibly, above the cut Tcut) is |
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| 42 | included (knock-on electron production with full kinematics) the possible way is to |
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| 43 | consider restricted multiple scattering (below Tcut). |
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| 44 | |
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| 45 | |
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