Spectroscopie des rayons X :
d�finitions, choix des raies, gammes d'�l�ments couverts

Typiquement, c'est un trou dans la couche K ( la plus proche du noyau) qui est combl� par un �lectron de la couche L, imm�diatement sup�rieure. Comme les niveaux d'�nergie des �lectrons sont li�s au Z - num�ro atomique - de l'atome, la technique PIXE donne une analyse en Z de la mati�re.

On utilise les r�gles suivantes pour nommer les raies X correspondantes :

• la raie adopte le nom de la couche "d'atterrisage" de l'�lectron : par exemple la transition <couche L-> couche K> donne une raie K.
• un indice grec identifie la couche dont provient l'�lectron : par exemple, la transition <couche M -> couche L> se nomme L_alpha

Ce sh�ma illustre les relations entre conventions de notation spectroscopiques et couches electroniques.

Les raies K sont utilis�es pour les �l�ments l�gers � moyens, tandis que les raies L sont mises � profit pour les �l�ments moyens � lourds. Mal mod�lis�es, les raies M ne sont pas utilis�es pour doser les �l�ments.

couche L,M -> couche K

1keV-40keV

11-60

Na-N

couches M,N,O -> couche L

1keV-20keV

30-92

Cu-U

Raies M

couche N,O -> couche M

1 keV-4 keV

60-92

Nd-U

Table d'�nergie des raies K et L des �l�ments

No. Element Ka1       Ka2       Kb1       La1       La2       Lb1       Lb2       Lg1

3   Li      0.0543
4   Be      0.1085
S   B       0.1833
6   C       0.277
7   N       0.3924
8   O       0.5249
9   F       0.6768
10  Ne      0.8486    0.8486
11  Na      1.04098   1.04098   1.0711
12  Mg      1.25360   1.25360   1.3022
13  Al      1.48670   1.48627   1.55745
14  Si      1.73998   1.73938   1.83594
15  P       2.0137    2.0127    2.1391
16  S       2.30784   2.30664   2.46404
17  Cl      2.62239   2.62078   2.8156
18  Ar      2.95770   2.95563   3.1905
19  K       3.3138    3.3111    3.5896
20  Ca      3.69168   3.68809   4.0127    0.3413    0.3413    0.3449
21  Sc      4.0906    4.0861    4.4605    0.3954    0.3954    0.3996
22  Ti      4.51084   4.50486   4.93181   0.4522    0.4522    0.4584
23  V       4.95220   4.94464   5.42729   0.5113    0.5113    0.5192
24  Cr      5.41472   5.405509  5.94671   0.5728    0.5728    0.5828
25  Mn      5.89875   5.88765   6.49045   0.6374    0.6374    0.6488
26  Fe      6.40384   6.39084   7.05798   0.7050    0.7050    0.7185
27  Co      6.93032   6.91530   7.64943   0.7762    0.7762    0.7914
28  Ni      7.47815   7.46089   8.26466   0.8515    0.8515    0.8688
29  Cu      8.04778   8.02783   8.90529   0.9297    0.9297    0.9498
30  Zn      8.63886   8.61578   9.5720    1.0117    1.0117    1.0347
31  Ga      9.25174   9.22482   10.2642   1.09792   1.09792   1.1248
32  Ge      9.88642   9.85532   10.9821   1.18800   1.18800   1.2185
33  As      10.54372  10.50799  11.7262   1.2820    1.2820    1.3170
34  Se      11.2224   11.1814   12.4959   1.37910   1.37910   1.41923
35  Br      11.9242   11.8776   13.2914   1.48043   1.48043   1.52590
36  Kr      12.649    12.598    14.112    1.5860    1.5860    1.6366
37  Rb      13.3953   13.3358   14.9613   1.69413   1.69256   1.75217
38  Sr      14.1650   14.0979   15.8357   1.80656   1.80474   1.87172
39  Y       14.9584   14.8829   16.7378   1.92256   1.92047   1.99584
40  Zr      15.7751   15.6909   17.6678   2.04236   2.0399    2.1244    2.2194    2.3027
41  Nb      16.6151   16.5210   18.6225   2.16589   2.1630    2.2574    2.3670    2.4618
42  Mo      17.47934  17.3743   19.6083   2.29316   2.28985   2.39481   2.5183    2.6235
43  Tc      18.3671   18.2508   20.619    2.4240    -         2.5368    -         -
44  Ru      19.2792   19.1504   21.6568   2.55855   2.55431   2.68323   2.8360    2.9645
45  Rh      20.2161   20.0737   22.7236   2.69674   2.69205   2.83441   3.0013    3.1438
46  Pd      21.1771   21.0201   23.8187   2.83861   2.83325   2.99022   3.17179   3.3287
47  Ag      22.16292  21.9903   24.9424   2.98431   2.97821   3.15094   3.34781   3.51959
48  Cd      23.1736   22.9841   26.0955   3.13373   3.12691   3.31657   3.52812   3.71686
49  In      24.2097   24.0020   27.2759   3.28694   3.27929   3.48721   3.71381   3.92081
50  Sn      25.2713   25.0440   28.4860   3.44398   3.43542   3.66280   3.90486   4.13112
51  Sb      26.3591   26.1108   29.7256   3.60472   3.59532   3.84357   4.10078   4.34779
52  Te      27.4723   27.2017   30.9957   3.76933   3.7588    4.02958   4.3017    4.5709
53  I       28.6120   28.3172   32.2947   3.93765   3.92604   4.22072   4.5075    4.8009
54  Xe      29.779    29.458    33.624    4.1099    -         -         -         -
55  Cs      30.9728   30.6251   34.9869   4.2865    4.2722    4.6198    4.9359    5.2804
56  Ba      32.1936   31.8171   36.3782   4.46626   4.45090   4.82753   5.1565    5.5311
57  La      33.4418   33.0341   37.8010   4.65097   4.63423   5.0421    5.3835    5.7885
58  Ce      34.7197   34.2789   39.2573   4.8402    4.8230    5.2622    5.6134    6.052
59  Pr      36.0263   35.5502   40.7482   5.0337    5.0135    5.4889    5.850     6.3221
60  Nd      37.3610   36.8474   42.2713   5.2304    5.2077    5.7216    6.0894    6.6021
61  Pm      38.7247   38.1712   43.826    5.4325    5.4078    5.961     6.339     6.892
62  Sm      40.1181   39.5224   45.413    5.6361    5.6090    6.2051    6.586     7.178
63  Eu      41.5422   40.9019   47.0379   5.8457    5.8166    6.4564    6.8432    7.4803
64  Gd      42.9962   42.3089   48.697    6.0572    6.0250    6.7132    7.1028    7.7858
65  Tb      44.4816   43.7441   50.382    6.2728    6.2380    6.978     7.3667    8.102
66  Dy      45.9984   45.2078   52.119    6.4952    6.4577    7.2477    7.6357    8.4188
67  Ho      47.5467   46.6997   53.877    6.7198    6.6795    7.5253    7.911     8.747
68  Er      49.1277   48.2211   55.681    6.9487    6.9050    7.8109    8.1890    9.089
69  Tm      50.7416   49.7726   57.517    7.1799    7.1331    8.101     8.468     9.426
70  Yb      52.3889   51.3540   59.37     7.4156    7.3673    8.4018    8.7S88    9.7801
71  Lu      54.0698   52.9650   61.283    7.6555    7.6049    8.7090    9.0489    10.1434
72  Hf      55.7902   54.6114   63.234    7.8990    7.8446    9.0227    9.3473    10.5158
73  Ta      57.532    56.277    65.223    8.1461    8.0879    9.3431    9.6518    10.8952
74  W       59.31824  57.9817   67.2443   8.3976    8.3352    9.67235   9.9615    11.2859
75  Re      61.1403   59.7179   69.310    8.6525    8.5862    10.0100   10.2752   11.6854
76  Os      63.0005   61.4867   71.413    8.9117    8.8410    10.3553   10.5985   12.0953
77  Ir      64.8956   63.2867   73.5608   9.1751    9.0995    10.7083   10.9203   12.5126
78  Pt      66.832    65.112    75.748    9.4423    9.3618    11.0707   11.2505   12.9420
79  Au      68.8037   66.9895   77.984    9.7133    9.6280    11.4423   11.5847   13.3817
80  Hg      70.819    68.895    80.253    9.9888    9.8976    11.8226   11.9241   13.8301
81  Tl      72.8715   70.8319   82.576    10.2685   10.1728   12.2133   12.2715   14.2915
82  Pb      74.9694   72.8042   84.936    10.5515   10.4495   12.6137   12.6226   14.7644
83  Bi      77.1079   74.8148   87.343    10.8388   10.73091  13.0235   12.9799   15.2477
84  Po      79.290    76.862    89.80     11.1308   11.0158   13.447    13.3404   15.744
8S  At      81.52     78.95     92.30     11.4268   11.3048   13.876    -         16.251
86  Rn      83.78     81.07     94.87     11.7270   11.5979   14.316    -         16.770
87  Fr      86.10     83.23     97.47     12.0313   11.8950   14.770    14.45     17.303
88  Ra      88.47     85.43     100.13    12.3397   12.1962   15.2358   14.8414   17.849
89  Ac      90.884    87.67     102.85    12.6520   12.5008   15.713    -         18.408
90  Th      93.350    89.953    105.609   12.9687   12.8096   16.2022   15.6237   18.9825
91  Pa      95.868    92.287    108.427   13.2907   13.1222   16.702    16.024    19.568
92  U       98.439    94.665    111.300   13.6147   13.4388   17.2200   16.4283   20.1671
93  Np      -         -         -         13.9441   13.7597   17.7502   16.8400   20.7848
94  Pu      -         -         -         14.2786   14.0842   18.2937   17.2553   21.4173
95  Am      -         -         -         14.6172   14.4119   18.8520   17.6765   22.0652

Valeurs extraites de J. A. Bearden, "X-Ray Wavelengths", Review of Modern Physics, (Janvier 1967) pp. 86-99