X-Ray Database

EPMA Xtreme Probe

 

CalcZAF Menu Details > X-Ray

X-Ray Database

This menu allows the user the view specified ranges of the NIST x-ray wavelength database. This database covers the wavelength range from approximately 0.5 to 100.0 angstroms and includes higher order reflections as well. Higher order reflections are reduced in intensity by 25% for each subsequent order to simulate the effect of PHA analysis.

 

The x-ray list range (Start Angstroms and Stop Angstroms) and minimum search intensity (Minimum Intensity) of the x-ray list can be specified by the user. Note that since the display is limited to about 1000 items, the program will automatically increase the minimum intensity until the returned list of x-ray lines is less than 1000. To view x-ray lines of lesser intensity, simply reduce the x-ray range and click the Re-Load button.

 

Note that angstrom values in the x-ray database list with Bragg reflection orders higher than one (Roman Numeral "I") are NOT corrected for refraction index corrections. However, KLM markers displayed in the Graph Data wavescan plot dialog are corrected using the equation A' = A * (1 - (K - (K / N^2))) where A is the uncorrected angstrom position, K is the refractive index from the CRYSTALS.DAT file and N is the Bragg reflection order.

 

Description of the X-ray Database (adapted from NIST documentation by C. Fiori)

The NIST x-ray database is based on 4985 (1st order) entries and includes all the  measurable x-ray  lines,  satellites  and  absorption edges from under 100 eV to over 120 keV. Additionally, most of the x-ray  lines  and  satellites are  assigned  a  relative intensity (relative to the alpha-1 line in each family).  The  data  base  was  assembled  primarily  from  four sources:

 

1.)  B.L.  Doyle, W.F. Chambers, T.M. Christensen, J.M. Hall and G.H. Pepper "SINE THETA SETTINGS FOR X-RAY SPECTROMETERS", Atomic Data and Nuclear Data Tables Vol. 24, No 5, 1979.

 

2.)  E.W. White, G.V. Gibbs, G.G. Johnson Jr. and G.R. Zechman "X-RAY WAVELENGTHS AND CRYSTAL INTERCHANGE SETTINGS  FOR  WAVELENGTH  GEARED CURVED CRYSTAL SPECTROMETERS" Report of the Pennsylvania State Univ., 1964.

 

3.) J.A. Bearden "X-RAY WAVELENGTHS AND X-RAY ATOMIC  ENERGY  LEVELS" Rev. Mod. Phys., Vol. 39, No. 78, 1967.

 

4.)  J.A  Bearden  and A.F. Burr,"REEVALUATION OF X-RAY ATOMIC ENERGY LEVELS", Rev. Mod. Phys., Vol. 31, No. 1, 1967.

 

Each x-ray line or edge series as a function of atomic number was fit to a fourth degree polynomial. The fit was subtracted from the appropriate data and the residuals plotted and examined. In this way rogue entries could be identified and corrected. The resulting data base is considered to be sufficiently accurate  for  any  application involving  the  Si (Li)  x-ray  detector and single crystal wavelength spectrometers.

Note that the last entry in the x-ray database window gives a  code  for the  source of the entry.  If  the column is blank the source is reference 2.  If the column contains the letter  "C"  the  source  is reference  1.  If the letters "BB" appear, the source is reference 4. The letters "W,F" mean that reference 2 was  used  but  the  relative transition  probability  has been adjusted by Fiori.  Reference 3 was used as a check since it is the source of  many of  the entries  of reference 1.

 

In column 3 the notation KA1,2 means the entry is the weighted sum of the KA1 and KA2 in the ratio 2 to 1. For  low  atomic  number  the entries  are  not  self-consistent  since the data is from different sources.  If the column begins with the capital  letter  S  then  the entry  is a satellite line due to doubly ionized atoms.   The relative transition values for these  entries  are  only  valid  for  electron excited specimens, and are, at best, estimates.

The following  are  Siegbahn  to shell-transition notation conversions:

KA   = KA1+KA2+KA3

KA1,2 = (2*KA1+KA2)/3

KA1  = K-L3

KA2  = K-L2

KA3  = K-L1

KB   = SUM(KBn)

KBX  = Metal

KB1  = K-M3

KB1' = KB1+KB3+KB5

KB2  = (K-N3)+(K-N2)

KB2' = K-N3

KB2'' = K-N2

KB3  = K-M2

KB4  = (K-N4)+(K-N5)

KB5  = (K-M4)+(K-M5)

KB5' = K-M5

KB5'' = K-M4

Kd1  = K-O3

Kd2  = K-O2

LA   = LA1+LA2

LA1  = L3-M5

LA2  = L3-M4

LB1  = L2-M4

LB10 = L1-M4

LB15 = L3-N4

LB17 = L2-M3

LB2  = L3-N5

LB3  = L1-M3

LB4  = L1-M2

LB5  = (L3-O4)+(L3-O5)

LB6  = L3-N1

LB7  = L3-O1

LB9  = L1-M5

LG1  = L2-N4

LG11 = L1-N5

LG2  = L1-N2

LG3  = L1-N3

LG4  = L1-O3

LG4' = L1-O2

LG6  = L2-O4

LG8  = L2-O1

Ll   = L3-M1

Ln   = L2-M1

Ls   = L3-M3

Lt   = L3-M2

Lu   = (L3-N6)+(L3-N7)

Lv   = L2-N6

MA1  = M5-N7

MA2  = M5-N6

MB   = M4-N6

MG   = M3-N5

MG2  = M3-N4

MZ1  = M5-N3

MZ2  = M4-N2

Md   = M2-N4

Me   = M3-O5