Description of archived elemental data
TABLE 1 Prompt Elemental Neutron-Capture Gamma Rays Sorted by Intensity
The prompt gamma rays from radiative capture of thermal neutrons adopted
for this element are listed after being sorted by decreasing intensity. The
gamma-ray energies (Eg) are in keV. The gamma-ray intensities (Ig) are per
100 neutron captures (or %) for that element. The isotope that captured the
thermal neutron (i.e., the target nucleus) to make that gamma ray is given in
the last column. Only gamma rays above a specified intensity threshold (given
in Table 3) are listed.
TABLE 2 Prompt Elemental Neutron-Capture Gamma Rays Sorted by Energy
The adopted prompt gamma rays from radiative capture of thermal neutrons
for this element are sorted in order of increasing energy. The gamma-ray
intensities (Ig) are per 100 neutron captures (or %) for that element. The
third column contains rounded-off values of the intensities from this work as
reported in Atomic Data and Nuclear Data Tables (ADNDT) for elements from H through
Zn (Z = 1 - 30). For intensities greater than 30%, the values in the ADNDT
article were later modified to include one digit after the decimal point.
The isotope that captured the thermal neutron (i.e., the target
nucleus) to make that gamma ray is given in the last column. Only gamma rays
above a specified intensity threshold (given in Table 3) are listed.
TABLE 3 Summaries and Data Used to Convert Isotopic Data to Elemental Data
The seven subtables of Table 3 give the data used to convert the
isotopic data for capture gamma rays to elemental data. They also provide
summary information for the prompt isotopic and elemental capture gamma-ray
data.
The first subtable lists the data used to calculate the fraction of
neutron captures by each isotope ("Reac Frac") for an element. The key data
for this calculation are the atom fraction of an isotope ("Atom-frac") and
that isotope's cross section in barns for radiative capture at thermal neutron
energies ("XS(b)"). The isotopic fractions are the ``representative isotopic
compositions'' of Table 1 from Rosman and Taylor, J. Phys. Chem. Ref. Data
vol. 27, pp. 1275-1287 (1998). The thermal cross sections are from Holden,
"CRC Handbookof Chemistry and Physics," Section 11 (1999). The "Reac Frac" is
the atomic fraction and cross section weighted contribution at thermal neutron
energies.
Reac Frac(iso) = [XS(iso)*Atom-frac(iso)]/[SUM(XS(iso)*Atom-frac(iso))]
The last two lines of the subtable give the calculated ("Totals") and measured
("Nat-elem") elemental atomic weights and capture cross sections (as a check
of the calculations) and determines the average amount of energy produced per
elemental capture (Sn, in keV). The elemental average energy is
Sn(element) = SUM (Reac-Frac(iso) * Sn(iso))
The second subtable gives summary information for the isotopic data. For
each isotope, Ng is the number of adopted gamma rays, S(Ig) is the sum of
isotopic intensities (in %), Sn is the neutron binding energy (in keV),
S(E*I)/Sn is the sum of Eg*Ig divided by Sn (in %), and S(cap) and S(grd) are
the sums (in %) of intensities of gamma rays from the capture state and into
the ground state. The quantity S(E*I)/Sn should be equal to 100.0% if all of
the capture gamma-rays have been measured. Additionally, if all the gamma-
rays out of the capture state or into the ground state have been measured,
S(cap) and S(grd) should be 100.0.
The third subtable gives, for each isotope, the number of gamma rays for
various intensity bins of Ig (10-100%, 1-10%, 0.1-1%, 0.01-0.1%, and <0.01%).
The number in each bin indicates the number of gamma rays that have an Ig
value greater or equal to the lowest bound for that bin and less than the
lower bound for the previous column. The upper bound for the first bin is
100%. Also given are the largest (I-max) and smallest (I-min) of the adopted
intensities (Ig).
The fourth subtable lists the maximum ("Imax") and minimum ("Imin")
isotopic ("-iso") intensities and elemental ("-el") intensities using the
reaction fractions calculated in the first subtable. The last two lines give
the largest value of Imin for that element (Imin-el) and the lowest value of
elemental intensity saved. If there are not many gamma rays, the lowest value
of the elemental intensity saved is often equal to the largest Imin-el. If
there are many gamma rays, a higher value is used so as not to list a huge
number of elemental gamma rays.
The fifth subtable gives the number and range of elemental intensities of
gamma rays saved for each isotope.
The sixth subtable summarizes the data saved for this element. Ng is the
number of gamma rays, S(Ig) is the sum of the intensities adopted for this
element in Tables 1 and 2 (in %), Sn is the elemental binding energy (in keV),
and S(E*I)/Sn (in %) is the sum of Eg*Ig divided by Sn. The table also lists
(in %) the largest (I-max) and smallest (I-min) of the adopted elemental
intensities. Note that this summary information only includes the gamma rays
listed in the tables and therefore often does not include the weakest gamma rays
for a specific element.
The last subtable gives the number of elemental gamma rays in various
intensity bins (30-100%, 10-30%, ... , 0.03-0.10%, 0.01.-0.03%, and <0.01%).
Each bin gives the number of gamma rays with Ig values greater to or equal to
the lowest bound for that bin and less than the lower bound for the previous
column. The upper bound for the first bin is 100%.