Radiation Physics and Chemistry 71 (2004) 653–654
WinXCom—a program for calculating X-ray
L. Gerward*, N. Guilbert, K.B. Jensen, H. Levring
Department of Physics, Technical University of Denmark, Building 307, DK-2800 Kongens Lyngby, Denmark
Data on absorption of X-rays and gamma-rays are
required for many scientific, engineering and medical
applications. Available tables, such as Hubbell and
Seltzer (1995), generally include cross-sections and mass
attenuation coefficients for the elements and a number
of compounds or mixtures. Instead of interpolating
tabulated values and using the mixture rule, a lot of
manual work can be saved by generating data as needed,
using a suitable software. Berger and Hubbell (1987/99)
developed XCOM for calculating mass attenuation
coefficients or photon interaction cross-sections for
any element, compound or mixture at energies from
1keV to 100GeV. Recently, this well-known and much
used program was transformed to the Windows plat-
form by Gerward et al. (2001). The Windows version,
called WinXCom, runs under the Windows operating
system and provides an interface that facilitates defining,
redefining and saving substances in a substance defini-
tion list. Once a substance has been defined, it can be
used for defining compounds or mixtures. It is even
possible to define mixtures of already defined com-
pounds or mixtures. The substance definition list comes
with a predefined list of the first hundred elements in the
periodic table (Z ¼ 12100).
WinXCom can generate cross-sections or attenuation
coefficients on a standard energy grid, spaced approxi-
mately logarithmically, or on a grid specified by the user,
or for a mix of both grids. The program provides total
cross-sections and attenuation coefficients as well as
partial cross-sections for incoherent and coherent
scattering, photoelectric absorption and pair produc-
tion. For compounds, the quantities calculated are
partial and total mass attenuation coefficients. Total
attenuation coefficients without the contribution from
coherent scattering are also given, since they are often
used in gamma-ray transport calculations.
WinXCom makes it possible to export the table of
cross-sectional or mass-attenuation data to a predefined
Microsoft Excel template. In this way, graphical display
and further data treatment is made easy (Fig. 1). The
ability of WinXCom to calculate attenuation data for
mixtures of compounds, defined by the user, comes in
handy when studying for example the radiation-shield-
ing properties of glasses (Singh et al., 2003). Fig. 2 shows
the mass attenuation coefficient for members of the
BaO–B2O3glass system at various energies in the 356–
1332keV range. The full lines represent theoretical
calculations using WinXCom. It is seen that there is
good agreement between theory and experiment.
ARTICLE IN PRESS
Fig. 1. Mass attenuation coefficient m=r; of lead (Pb) as a
function of photon energy E, in the 5–1000keV range.
*Corresponding author. Tel.: +45-45-25-3146; fax: +45-45-
E-mail address: firstname.lastname@example.org (L. Gerward).
0969-806X/$-see front matter r 2004 Elsevier Ltd. All rights reserved.
WinXCom is free to use with due reference to the
original papers. The main goal of the reengineering
project was to port the original 16 bit DOS program to
the 32 bit Windows platform, thereby modernizing its
user interface. In addition to referencing the short
descriptive paper by Gerward et al. (2001), it would be
appropriate to also reference the original report by
Berger and Hubbell (1987/99) detailing all the physics
input to XCOM, the underlying NBS/NIST data base
and the calling program from which WinXCom was
One of the authors (LG) wishes to thank John H.
Hubbell for invaluable advice and encouraging support
over many years. WinXCom, its users’ guide, and other
relevant material are available on request. Please contact
the corresponding author of the present paper.
Berger, M.J., Hubbell, J.H., 1987/99. XCOM: Photon Cross
Sections Database, Web Version 1.2, available at http://
physics.nist.gov/xcom . National Institute of Standards and
Technology, Gaithersburg, MD 20899, USA. Originally
published as NBSIR 87-3597 ‘‘XCOM: Photon Cross
Sections on a Personal Computer’’.
Gerward, L., Guilbert, N., Jensen, K.B., Levring, H., 2001.
X-ray absorption in matter. Reengineering XCOM. Radiat.
Phys. Chem. 60, 23–24.
Hubbell, J.H., Seltzer, S.M., 1995. Tables of X-ray Mass
attenuation Coefficients and Mass Energy-Absorption
Coefficients 1keV to 20MeV for Elements Z=1 to 92 and
48 additional substances of dosimetric interest. NISTIR
5632, National Institute of Standards and Technology,
Gaithersburg, MD, USA.
Singh, H., Singh, K., Sharma, G., Gerward, L., Nathuram, R.,
Lark, B.S., Sahota, H.S., Khanna, A., 2003. Barium and
calcium borate glasses as shielding materials for x-rays and
gamma-rays. Phys. Chem. Glasses 44, 5–8.
ARTICLE IN PRESS
Fig. 2. Mass attenuation coefficient m=r; for the BaO–B2O3
glass system at 356, 511, 662, 1173 and 1332keV. NB, the
1173keV data are indicated by filled triangles, and the 1332keV
data by open squares. The composition is given by w=mass
fraction of BaO. The full lines represent theoretical calculations
using WinXCom software.
L. Gerward et al. / Radiation Physics and Chemistry 71 (2004) 653–654