is a Hauser-Feshbach statistical model code
for an energy and temperature range which is interesting
for astrophysical purposes. It is related to the well-known SMOKER and
Calculations in the statistical model require the input of a
different nuclear properties:
Although the model is well-established, different
calculations vary in the various inputs and treatments of such
properties. In the calculations presented here, it was attempted to
descriptions which can be used to predict nuclear properties also for
nuclei far off stability for which no experimental data is known.
Therefore, it was tried to minimize the direct input of experimental
data (although some parametrizations are fit to available nuclear
Thus, we are interested in descriptions which lead to a low
deviation between predicted and observed
Nevertheless, local deviations of higher magnitude can occur.
Different options can be chosen as input to the statistical
The default values are those used in the calculations published in
ADNDT 75 (2000) 1
and 79 (2001) 47 (except for experimental masses which have
For a more detailed explanation of the options see those papers and
the reference section.
Important note: The default settings of the code make use of global
inputs, attempting to include as few local information as possible. For
a fair comparison to other codes be aware that many other codes include
a lot of local information (such as level densities or GDR properties) for
nuclei at stability. When performing such comparisons, the NON-SMOKERWEB
settings should be chosen accordingly!
To run NON-SMOKERweb
the user has to
be registered. If you want to
start a collaboration and use NON-SMOKERweb
please use the Registration Form
specifying in detail what you want to use the code for.
You will then
be sent a username and password shortly. The access may be restricted
certain targets or projectiles and certain options.
The HTML interface
should be quite
self-explanatory. In the element box, the standard abbreviation of the
should be input, as it is used in periodic systems or nuclear charts;
for Neon or
for Gold (input is not case
sensitive). The massnumber is an integer with 2 or 3 digits.
Options and Output
The recommended set of options is the default,
therefore it should be sufficient in most cases to just enter element
and mass number and to select which kind of projectile one wants to
use. The output will contain the nuclear reaction cross sections for
channels (gamma, n, p, alpha) depending on which projectile was chosen.
also contain the astrophysical reaction rates. For reactions with a
projectile, the Maxwellian averaged cross sections (MACS) are
written whereas for charged particle induced reactions the
S-factor is additionally written. For astrophysical applications it is
necessary to know the reactions on targets in the ground state but also
thermally excited targets. The reaction rates and MACS are both given
g.s. and thermally excited targets, cross sections and S-factors only
targets being in the g.s.
By default, in the calculations experimental values are used if
available (for the current status of the experimental masses included,
see also the history section.
The setting of the theoretical mass will affect
experimentally unknown masses (separation energies), as well as the
level density for all nuclei if the default level
The FRDM covers the widest mass range, ETFSI values are available only
for A>35, and the ETFSIQ table starts at Cr (Z>23).
Hint: The output can be saved by
the returned page and then selecting "Save as..." and the appropriate
format (usually, that is text format). This yields a nice text file
which can be inspected further. (For further hints, see
Using a custom input file offers even more
flexibility than the options
directly provided on the web
. In order to use a file, the
appropriate option on the web
has to be checked and a file location
has to be provided in the appropriate field. On submission of the
, the file will be loaded and the appropriate data used
(if the file
contains more than the data required by the checked options, the excess
data will be ignored). For each calculation, the input file will be
loaded again from the specified location. The input file is an ASCII
file which contains options and data in a specific
. Invalid input files will trigger error messages.
- The input file is a plain ASCII file (text file). The
name of the
file is irrelevant but some browsers do not assume to be sending a
plain text file when the extension is something else than .txt,
.dat, or .inp and
they might encode it inappropriately.
Therefore one of these file extensions
should be used preferentially.
Take a look at the sample
input file (the data contained therein is just for
purposes and does not have any real physical meaning) and modify it for
your own purposes.
- The maximum length of a line in the input file is 500 characters. If that length is exceeded, errors or unwanted behavior of the code may result!
- Data is organized into sections which start with an
end with the general end-identifier END. The
order of the sections is
irrelevant but they have to be between the INPUT_START
labels. Everything outside of these labels or between sections is
uses input only from sections which correspond to the
options selected on the web form.
All other data is ignored.
- Section labels (identifiers) and special labels start
'#*'. They are case sensitive!
- Comment lines use an '#' as first
character (and don't
have an '*' as second character) and can appear
everywhere. Blank lines are ignored.
- Some details:
- Optical potentials:
- Section labels: CUSTOM_ALPHA,
- For the proton and alpha potentials, the first
entry in the section
defines the Coulomb radius rc.
The value of the
radius has to follow the label on the same line:
(For the neutron potential there is no such line; it is an error if
a line is present.)
- Within these sections there are two subsections
each (both have to
be specified): The real part of the optical potential is defined from
the beginning of the section to the label REALEND;
imaginary part is defined after the label REALEND
up to the
- Within each of the two subsections, there are two
ways to specify
the potential: Either by explicitely giving data points or by providing
an algebraic expression to compute the potential. The first method is
selected with the label DATA, the second with
EXPRESSION. Each of these labels have
to be given before any
data or expression in that subsection.
- Option DATA:
Pairs of radius (in fm) and potential
depth (in MeV) are given. At most 800 pairs can be given. They don't
have to be equidistant but have to be in ascending order by radius (and
all radii have to be different). Points between the given data are linearly
interpolated. At least two pairs have to be given explicitly.
Above and below the first and last point, respectively, the potential is
extrapolated using the same slope as between the last two known points. (If you
want the potential to become constant, specify a depth twice.)
- Option EXPRESSION:
Specify a function to compute
the optical potential part at a given radius. See the detailed explanation of custom potentials
whitespace characters (including blanks, tabs, newlines) are ignored,
they can be used to structure the input for better (user) legibility.
The current upper length limit is 500 characters (not counting
- Level density:
- Section label: CUSTOM_LEVEL_DENSITY
- Custom parameters for a shifted Fermi-gas
description of the nuclear
level density can be provided here. The order of parameters is charge
mass number A, level density parameter a (in MeV-1),
Delta (in MeV).
- During a calculation the default level density (see
used unless Fermi-gas paramaters have been specified for that nucleus.
In the latter case a Fermi-gas level density with those parameters is
used. At low excitation energies, a constant temperature formula is
in both cases to avoid the divergence of the Fermi-gas description.
- Section label: MASSES
- Each entry contains charge Z, mass number A, and
the mass excess (in
- During a calculation the default mass (either
theoretical, see web page)
is used unless the mass excess for
that nucleus has been specified in the input file. An explicitly
defined mass excess is always used when it is found in the input file.
- To change a separation energy, specify the proper
two masses but
keep in mind that an altered mass also may affect the separation
energies in other reaction channels.
- Excited states:
- Section label: EXCITED_STATES
- Low-lying excited states can be specified for a
number of nuclei.
Each nucleus has its own subsection which starts with the specification
of charge Z and mass number A, and ends with the label NUCEND
(or END for the last nucleus in the list).
- After the Z-A identification of the nucleus, a list
states follows with one entry per line, giving excitation energy (in
MeV), spin (in multiples of 1/2), and parity (positive/even parity when
the spin integer is >= zero, negative/odd parity with spin
- The ground state (zero excitation energy) has to be
- There is an upper limit of how many states (including g.s.) can be
specified. The value depends on the code version you are using. More states
will not trigger an error message but will simply be ignored.
- If no states are explicitely specified for a given
default states (from Table of Isotopes) are used. Otherwise, the
levels are superseded by the ones in the input file.
- Breit-Wigner Resonances:
NON-SMOKERweb can also
calculate Breit-Wigner resonance parameters and cross sections.
- For the compound nucleus of the reaction, put
in excited states
above the separation energy of the
projectile (this only works
for neutron- and proton-induced reactions). This will
prompt NON-SMOKERweb to also compute and output
- Most likely the other output (cross sections,
rates, ...) is
meaningless in this case. Remember that there still is a limit on the number of
states including the g.s (see above). Try to put in as many low-lying resonances as
- Target range:
- Section label:
- There are two ways to specify more than one target.
distinguished by the labels EXPLICIT and GRID,
have to appear before any data in this section. If the label
EXPLICIT is found, a list of target
nuclei is expected to follow, one per line. With the option
GRID, a range can be defined.
- Option EXPLICIT: Specify
charge Z and mass number A of a target
nucleus. There can be several lines like that, each specifying another
- Option GRID: Specification of
a Z-N range of target nuclei. The
order of supplied values is Z_start N_start Z_end N_end. There can only
be one line of this kind.
- Options EXPLICIT and GRID
cannot be mixed.
- Some hints:
- Before submitting an input file, check its validity
checker tool! This is a C program which accepts a
file name on the command line and returns more detailed error messages
than the web interface
(which will only tell you that there was a
problem with the file). You need a C-compiler to make an executable for
your architecture. Precompiled executables are provided for Linux and DEC Alpha.
- It is advisable to keep a log on what you have changed
in the input
file during different runs. The result page returned by
NON-SMOKERweb only shows the selected options
but not the
content of the file, unless the "Echo file content" checkbox is
Even in the latter case, the whole input file is echoed, not just the
- Since only those sections are used which have been
selected in the
options, sections in the input file can be selectively
switched on and off without the need to remove or modify them.
- On the other hand, if you want to make changes in the
input file but
not in the selected options, you can just hit the reload/update button
your browser to start a new calculation.
- Access control restrictions apply equally to the
options on the web
page and to the input file. It is not possible to select
sections in an
input file for which the user does not have access permission.
- For expert users,
there are also advanced
options available. Do not
bother with those unless you really know what you are doing!
A speciality in this interface is the possibility to put in new
for the optical potentials. If
you are not satisfied with the provided options, you can provide a
in the custom area. Here are some guidelines what to put into the
- Functions can be written as FORTRAN style expressions,
brackets. The input is not case sensitive.
- Whitespaces (blanks, tabs, newlines) are ignored in the
of the expression. This can be used to more nicely structure the input.
Note that the allowed line length in the input file may be shorter than
the maximum length of the expression! For a longer expression it is
strongly suggested to distribute it across several lines. Otherwise an
error may result.
- The standard arithmetic operators + - * / are known.
can be written either as ** or as ^. Additionally, the following
functions are known:
The usual limits on the arguments of those functions apply.
- exp(x)...exponentiation of Euler's number, e^x
- log(x)...natural logarithm of x
- sqrt(x)...Square root of x
- For comparison of two values, the test operator '<'
can be used. (Note that there is NO '>' operator!)
An expression x<y will return 1 if x is
smaller than y and
0 otherwise. This can be used to switch between different potential
depending, e.g., on the energy. See the examples below on how to use
operator. The operator precedence is stronger than + - * /
but equal to exponentiation and the functions exp, log, sqrt.
It is recommended to always use brackets to ensure the right order
of operator evaluation.
- Numbers can be input in various formats, e.g. 1 1. 1.0
1.0e+00 . All numbers are treated as double precision regardless of
their input format. Likewise, all computations are performed in double
- If desired, an equation-like input can be used, e.g.
mymath=1+sqrt(3/2). Everything to the left of
the equation sign
is ignored, only the RHS is used for computation.
- Four variables (not case sensitive) can be used in the
- r...potential radius in fm
- en...c.m. energy of projectile-target system in MeV
(for energy-dependent potentials)
- c...Coulomb barrier in MeV
- f...Currently, this is set to be A**(1./3.). Caution:
The meaning of
this variable may change in the future, based on common practice.
- Examples for valid expressions:
Please keep in mind that NON-SMOKERweb
whether the input
functions actually make any sense for an optical potential. It
blindly uses the computed values as real and imaginary parts of the
optical potential. Unreasonable expressions may lead to unreasonable
results or a crash of the code. The latter is just visible by an
incomplete result page, explicit error messages are not always shown.
Applicability of the model
Please be aware that
the statistical model may
not be applicable below
a certain energy
or temperature, although values are given below that limit. The
statistical model assumes that averaged transmission functions can be
used, i.e. averaging over resonances in the contributing energy window
is permitted. At lower excitation energy of the compound nucleus, fewer
resonances will be available and thus there may be a lower
energy/temperature limit for the application of the model.
An estimate of the limiting energy/temperature was derived
in a previous paper
and is also
explicitly given in ADNDT 75 (2000) 1
The applicability limits can also be checked by calling a result from
the standard result
database and looking for possible applicability
warning messages in the output. (See also the explanations
of the database.)
It has to be emphasized that very conservative assumptions are used and
that the given results may be valid even below the given limit. The
warning is merely issued to point out that one should be cautious and
aware of the limitations.
There may be another limitation inherent to all statistical
calculations which do not explicitly include gamma cascades in the
compound nucleus. Treating the cascades and the particle escape from
cascade only approximately may lead to larger errors for reactions with
negative reaction Q values, i.e. for endothermic
is not necessarily the case but, in general, for these cases it is
to calculate the reverse reaction (with positive Q
compute the desired reaction by applying detailed balance.
Referencing the results
When using NON-SMOKERweb and the
linked pages, credit
should be given to the access
and the author.
Do not forget to quote the version number you used because
different versions may yield different results. The version
number is given at the top of each result page returned by the web interface.
The desired way of quoting would be, e.g., "...obtained with NON-SMOKER(WEB) v5.9.1w...".
I would appreciate it if a copy of the work is
sent to me (e.g. at )
publication, so that misconceptions or misinterpretations of the
can be avoided.
Please see also the disclaimer.
There are several error messages which can be returned
instead of the
requested result. They should be self-explanatory. In addition to
errors arising from access control or incorrect specifications in the
target options, there can be fatal errors when using the customized
option. These errors will be shown at the end of an incomplete result
and they always refer to a problem with the functions entered in the
area. Please check your input carefully!
If you encounter a failure or an inexplicable result, please
the explanation of NON-SMOKERweb
and the used methods.
Consult the history section for
of the current release.
In case you still think that there
might be a bug in the returned result, please
send a bug report by email,
specifying exactly what you did and where you see the problem.
This history list is being discontinued. Look in the forum
for information on updates and revisions.
Migration to new server and layout change in the web pages. The function
of the code should be unaffected.
01-Jun-2006 to 02-Jun-2006
Server temporarily unavailable due to scheduled power shutdown.
Version 3.3w: Minor changes and bug fixes.
09-Jul-2005 to 11-Jul-2005
Temporarily unavailable due to hardware problem!
Version 3.2w: Add Coulomb radius parameter in definition of external
- Requires new sample input files.
- New version of checker (Websmokertools Version 2.2) to
- Additional advanced option (deformation).
Version 3.1w: New advanced option and bug fix (specification of
Version 3.0w: File upload from any directory readable by the user
(external file does not have to be in a WWW directory anymore). Some
minor bug fixes.
Switched to HTTP POST for sending the form. That means that the result
page cannot be bookmarked or linked anymore!
Version 2.01w. Some bug fixes concerning inclusion of experimental
masses and custom potentials.
Version 2.0w. Update of experimental masses. Now the experimental and
recommended masses from the Audi mass evaluation 2003 are used.
Version 1.1w. New options for custom input file.
Going on-line with version 1.0w!
This version also includes E2 gamma-transitions (the published
standard results only use E1 and M1).