Exhaustive Nuclear Search and Analysis Package

User Manual

CONTENTS

  • What is ENSAP?
  • Features
  • Database
  • Installation
  • Quick Start
  • Examples
  • ENSAP command line
  • Isotope Specifications
  • Isotopic and Chemical Data
  • Electric Quadrupole Moments
  • Decay Chains
  • Command Line Options
  • Interpreting the Output
  • Decay modes
  • Spin and parity Considerations
  • Weak Interaction
  • Gamow Supression Factors
  • Coping with abundant Output
  • Sorting the generated Output
  • Limitations of the Demo version of ENSAP
  • Disclaimer
  • Acknowledgements
  • References

    Author: mr.collis@physics.org

    Updated: 14 January 2013

    (C)opyright William Collis 1994-2013.  All rights reserved.

     Strada Sottopiazzo 18, 14055 Boglietto(AT), ITALY

    What is ENSAP?

    ENSAP is a general purpose nuclear reaction program which will run under DOS on almost any PC (x86). An easy port to Unix.  It calculates Q values, spin and parity changes for a one or more reactions of the form:-

         A + B -> C + D

    The user may optionally impose restrictions including spin conservation, parity conservation, product stability etc.  Only reactions conserving proton and neutron number are normally considered.  The program can provide additional information on natural abundances or decay modes.  Output is in ASCII form for direct insertion into a word processor.  A simple option transforms superscripts into HTML format if required.

    Features

    Only 2 Reactants / Products?

    At first sight it may seem that the simple reaction scheme above with no more than two products and/or reactants is too restrictive.  In practice there are few reactions at low energy which are not covered.   One notable exception is solar fusion of 3He which produces 2 protons as well as 4He.

    3He(0.00%)

    + 3He(0.00%)

    ->2p

     

    + 4He( 100%)

    +12.859 MeV

    ENSAP correctly deals with this kind of situation of  double nucleon emission with the notation 2p or 2n.

    Database

    The database is based on 2004 data provided by the Brookhaven National Laboratory and has been extensively checked for consistency.  The standard database originally contained 2900 nuclides, augmented to 3190 in 2012 with updated mass measurements from the 2012 Atomic Mass Evaluation (see refs). If you would like to see what the database contains, try listing the attributes of all the isotopes using the command:-

        ENSAP *

    ENSAP will display over 2900 lines of data!  (The asterisk means all isotopes as we shall see later).

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    Installation

    No installation required!  Just copy the program ENSAP.EXE to any suitable directory on your hard disk.  ENSAP is a stand alone program and already contains the entire isotope database.  Both the program and database are highly compressed to save disk space and to load faster.  No other files are required.

    Quick Start

    ENSAP is an MS-DOS program running at the command line.  A help screen is displayed on running ENSAP with no parameters.  A quick way to understand how to use the program is to try the examples in the next section.

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    Examples

    The best way to learn, is to try some examples yourself:-

    ENSAP     p ? n *           Neutrons from protons

    ENSAP     e ? #             Electron capture by natural isotopes

    ENSAP     . ? e             Natural beta- decay

    ENSAP     . ? e+            Natural beta+ decay (positron emission)

    ENSAP     . ? He4           Natural alpha instability

    ENSAP     . ? ! !           Natural fission - beta stable products

    ENSAP     H H               All fusion combinations between p, d and t.

    ENSAP     p Hg Ag *90      Natural silver and mass 90

    ENSAP     *                 List contents of database

    ENSAP     Pd                List palladium isotopes and properties

    ENSAP     Dy154             Display properties and decay chain

  •  

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    ENSAP command line

    ENSAP expects two reactants to be specified and up to two products.  If a product is not specified then ENSAP assumes '*' which means any isotope.

    In addition you may want to specify command line options.  Options must start with the '/' character.  You can specify options in any order, group them together, or even mix them with the other parameters.

    For example the following 2 lines mean exactly the same thing:-

         ENSAP /esp H1 H2

         ENSAP p d  /p /e /s

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    Isotope Specifications

    Products and reactants are specified in simple notation using standard element symbols and / or mass numbers.  For example:-
    Agany natural Silver isotope.
    Ag110    the radioactive 110Ag isotope.
    Ag*all Silver isotopes
    nneutron.
    pprotium (same as H1).
    ddeuterium (same as H2).
    ttritium (same as H3).
    ?any natural isotope.
    !any natural or beta stable isotope plus n and t.
    qany beta stable nuclide with nuclear quadrupole moment
    *any isotope.
    *100any isotope with mass 100.
    #a massless particle (photon/phonon)with spin 1+.
    .nothing (spin 0+).
    bany beta unstable isotope.
    +any isotope unstable to electron capture or positron decay.
    -any beta- unstable isotope.
    aany beta stable unnatural isotope (alpha unstable).

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    Isotopic and Chemical Data

    When only one isotope specification is defined, ENSAP displays the corresponding isotopic data.  If the isotope specification refers to one element only, then in addition some pysical / chemical data is also displayed.  For example ENSAP displays details of Tin in response to the command line:-

         ENSAP Sn*

     

    Isotope

    Delta MeV

    Atomic Weight  

    Spin/

    log10

    EQM

     

     

     

    Parity  

    Halflife  

    mbarns

    100Sn(beta+)

    -56.4630

    99.939385

    0+

    +0.00

     

    101Sn(beta+)

    -59.5600

    100.936060

    ?-

    +0.48

     

    102Sn(beta+)

    -64.7480

    101.930491

    0+

    -6.70

     

    103Sn(beta+)

    -66.9460

    102.928131

    5/2-

    +0.84

     

    104Sn(beta+)

    -71.5523

    103.923186

    0+

    +1.32

     

    105Sn(beta+)

    -73.2329

    104.921382

    5/2-

    +1.49

     

    106Sn(beta+)

    -77.4281

    105.916878

    0+

    +2.06

     

    107Sn(beta+)

    -78.5625

    106.915660

    5/2+

    +2.24

     

    108Sn(beta+)

    -82.0132

    107.911956

    0+

    +2.79

     

    109Sn(beta+)

    -82.6348

    108.911289

    5/2+

    +3.03

     

    110Sn(E.C. )

    -85.8337

    109.907854

    0+

    +4.17

     

    111Sn(beta+)

    -85.9430

    110.907737

    7/2+

    +3.33

     

    112Sn(0.97%)

    -88.6579

    111.904823

    0+

     

     

    113Sn(beta+)

    -88.3295

    112.905175

    1/2+

    +7.00

     

    114Sn(0.65%)

    -90.5571

    113.902784

    0+

     

     

    115Sn(0.34%)

    -90.0314

    114.903348

    1/2+

     

     

    116Sn(14.5%)

    -91.5235

    115.901746

    0+

     

     

    117Sn(7.68%)

    -90.3967

    116.902956

    1/2+

     

     

    118Sn(24.2%)

    -91.6517

    117.901609

    0+

     

     

    119Sn(8.58%)

    -90.0656

    118.903311

    1/2+

     

     

    120Sn(32.6%)

    -91.1015

    119.902199

    0+

     

     

    121Sn(beta-)

    -89.2009

    120.904240

    3/2+

    +4.99

     

    122Sn(4.63%)

    -89.9440

    121.903442

    0+

     

     

    123Sn(beta-)

    -87.8186

    122.905724

    11/2-

    +7.05

     

    124Sn(5.79%)

    -88.2362

    123.905275

    0+

     

     

    125Sn(beta-)

    -85.8979

    124.907786

    11/2-

    +5.92

     

    126Sn(beta-)

    -86.0199

    125.907655

    0+

    +12.50

     

    127Sn(beta-)

    -83.5081

    126.910351

    11/2-

    +3.88

     

    128Sn(beta-)

    -83.3360

    127.910536

    0+

    +3.55

     

    129Sn(beta-)

    -80.6299

    128.913441

    3/2+

    +2.13

     

    130Sn(beta-)

    -80.2424

    129.913857

    0+

    +2.35

     

    131Sn(beta-)

    -77.3831

    130.916926

    3/2+

    +1.75

     

    132Sn(beta-)

    -76.6204

    131.917745

    0+

    +1.60

     

    133Sn(beta-)

    -71.1264

    132.923643

    7/2-

    +0.08

     

    134Sn(beta-)

    -67.2260

    133.927831

    0+

    +0.05

     

    Tin (Atomic Number 50) is a metal known from antiquity.

     

    IUPAC

    Melting

    Boiling

    Density

    First

    Electro-

    Terrestrial

    Group

    Point °K

    Point °K

    g/ml

    Ioniz.

    Negat.

    Abundance

    14

    505

    2543

    7.30

    169

    1.80

    0.018

    Notes:

    The IUPAC (International Union of Physics and Chemistry) Group denotes the group in the periodic table.

    Melting and noiling points are in degrees Kelvin.

    Terrestrial Abundance is relative to Silicon set to 100.

     

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    Electric Quadrupole Moments

    The EQM column on the listing on the previous page shows the electric quadrupole moment in mBarns of most beta stable or naturally occurring isotopes.  Such isotopes can be specified by the symbol 'q' on the command line.  Generally an isotope has a significant quadrupole moment if its spin is greater than 1/2.

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    Decay Chains

    When the single isotope specification refers to one particular radio-active nucleus, its decay chain is displayed.  Note that this feature does not show all possible decays if multiple channels are available (ie not both alpha and beta decay).  However ENSAP makes an intelligent guess as to which channel is likely.  Spontaneous fission is not considered.

         ENSAP Fm252 /a

    Isotope

    Delta MeV

    Atomic Weight  

    Spin/

    log10

    EQM

     

     

     

    Parity  

    Halflife  

    mbarns

    252Fm

    +76.8102

    252.082458

    0+

    +4.96

     

    252Fm

    + .

    ->

    4He

    +248Cf

    +7.153 MeV

    [0]

     

     

    248Cf

    + .

    ->

    4He

    +244Cm

    +6.361 MeV

    [0]

     

     

    244Cm

    + .

    ->

    4He

    +240Pu

    +5.902 MeV

    [0]

     

     

    240Pu

    + .

    ->

    4He

    +236U

    +5.256 MeV

    [0]

     

     

    236U

    + .

    ->

    4He

    +232Th

    +4.572 MeV

    [0]

     

     

    232Th

    + .

    ->

    4He

    +228Ra

    +4.083 MeV

    [0]

     

     

    228Ra

    + .

    ->

    e-

    +228Ac

    +0.046 MeV

    [2]

     

     

    228Ac

    + .

    ->

    e-

    +228Th

    +2.127 MeV

    [2]

     

     

    228Th

    + .

    ->

    4He

    +224Ra

    +5.520 MeV

    [0]

     

     

    224Ra

    + .

    ->

    4He

    +220Rn

    +5.789 MeV

    [0]

     

     

    220Rn

    + .

    ->

    4He

    +216Po

    +6.405 MeV

    [0]

     

     

    216Po

    + .

    ->

    4He

    +212Pb

    +6.906 MeV

    [0]

     

     

    212Pb

    + .

    ->

    e-

    +212Bi

    +0.574 MeV

    [0]

     

    PV

    212Bi

    + .

    ->

    4He

    +208Tl

    +6.207 MeV

    [4]

     

    PV

    208Tl

    + .

    ->

    e-

    +208Pb

    +5.001 MeV

    [4]

     

     

    PV indicates a parity violation which may inhibit the rate of reaction

     

    Command Line Options

         /a -> Do not show relative isotopic abundance/decay mode

         /e -> Allow endothermic reactions

         /en-> Add n keV (external energy) to reaction

         /g -> Show gamow suppression factor (log10)

         /m -> Wait for a key press before showing next screen

         /p -> Conserve parity

         /s -> Conserve spin

        /h -> Output in HTML format

     

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    Interpreting the output

    As an example let us consider all possible nuclear reactions between natural hydrogen isotopes.  This class of isotopes is designated by the chemical symbol H, and includes tritium. (Strictly speaking, tritium is present in such tiny quantities on earth that it hardly deserves the title natural.  In fact, in the example tritium is shown as beta unstable with no natural abundance.)  This search is invoked by:-

         ENSAP H H

    and produces the following output:-
    1H (100.%) + 2H (0.02%) -> g + 3He(0.00%) +5.494 MeV [0]    
    1H (100.%) + 3H (beta-) -> g + 4He(100.%) +19.814 MeV [0]    
    2H (0.02%) + 2H (0.02%) -> g + 4He(100.%) +23.846 MeV [1]    
    2H (0.02%) + 2H (0.02%) -> 1n (beta-) + 3He(0.00%) +3.269 MeV [0]    
    2H (0.02%) + 2H (0.02%) -> 1H (100.%) + 3H (beta-) +4.033 MeV [0]    
    2H (0.02%) + 3H (beta-) -> g + 5He(n ) +16.695 MeV [0]    
    2H (0.02%) + 3H (beta-) -> 1n (beta-) + 4He(100.%) +17.589 MeV [0]    
    3H (beta-) + 3H (beta-) -> g + 6He(beta-) +12.305 MeV [0]    
    3H (beta-) + 3H (beta-) -> 1n (beta-) + 5He(n ) +10.438 MeV [0]   PV
    3H (beta-) + 3H (beta-) -> 2n (beta-) + 4He(100.%) +11.303 MeV [0]    

     Because the /e option was not specified, only exothermic reactions are shown so the Q values in MeV are all positive.  The digit in square brackets is the minimum spin change for the reaction.  Reactions are favoured when spin is conserved.  So in the above example we would not expect 4He to be a major product in deuterium fusion and such is indeed the case experimentally. 

    The natural abundance of the product and reactant isotopes is shown in round brackets.  All known stable isotopes exist naturally on earth, although some such as 3He are very rare.  Unnatural isotopes are all radioactive and have since decayed.  In this case, instead of showing a zero abundance, the decay mode is displayed.  For example, the 5He above decays by neutron emission.

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    Decay modes include: -

         (alpha)         Unstable to emission of 4He.

         (beta+)        Unstable to positron emission / electron capture.

         (beta-)         Unstable to electron emission.

         (E.Cap)       Unstable to electron capture (but stable to positron emission).

         (p    )           Unstable to proton emission.

         (n    )           Unstable to neutron emission.

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    Spin and Parity Considerations

    If the spin change for a reaction cannot be calculated because the spin of one or more component isotopes has never been measured, this is shown as [?].  You can check the spin values of any isotope or group of isotopes by invoking ENSAP with a single isotope specification (see Quick Start examples).  If the s option is specified only reactions which conserve spin will be displayed and in this case the spin change will not be shown. 

    Similarly if the p option is specified, only reactions which conserve parity will be displayed.  A parity violation is shown by the designation PV.  Note that parity is always conserved for reactions involving photons / phonons.

    Note that all spin, parity and energy calculations are based upon isotopes in their ground states.  The only exception to this rule is for 180Ta which occurs naturally in an excited 9- state with a half life of more than 1015 years.  The 1+ ground state in contrast has a half life of about 8 hours.

     

    Weak Interactions

    Normally ENSAP only considers reactions which conserve proton and neutron number (strong force reactions).  However by specifying an electron (e) or positron (e+) beta decays can be accommodated.  Although not shown, it is implicit in the use of this notation that an accompanying neutrino or anti-neutrino is involved.  The spin of the two leptons may or may not be aligned.  For the time being ENSAP considers that the spin of the pair is 0 when in fact it could be 1.  The result of this assumption is that the calculated reaction spin may not be minimized.  However when ENSAP shows that reaction spin is conserved, this is correct.

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    Gamow Supression Factors

    Nuclear fission is energetically possible for many isotopes, but in practice does not occur or proceeds only slowly.  This effect was examined by Gamow in 1928 who showed that there was an electrostatic Coulomb barrier inhibiting the separation of the charged products.  The strong short range nuclear force must be overcome to disrupt and fission a nucleus, but the longer range electrostatic energy is only released when daughters are well separated.  Consequently the most probable fission channels are not necessarily those which generate the most energy. Other considerations such as the greater tunnelling ability and lower charge of lighter products come into play.

    ENSAP uses a simple formula for calculating the suppression factor due to the Coulomb barrier.  This formula assumes that the daughter nuclei are perfect spheres.  This produces excellent results for alpha emission over a very wide range of energies.  However heavier nuclei are not spherical, and the formula is too pessimistic.

    ENSAP shows the Gamow factor in units of -log10 rounded to the nearest integer.  In the case of alpha decay you can estimate a half life in seconds by subtracting 23.  (A typical nuclear time is 10-23 S).

    It is also possible to limit displayed reaction to those most probable by specifying a Gamow limit.  For example the option /g40 limits reactions to those with a Gamow supression factor of 40 or better.

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    Coping with abundant output

    ENSAP can easily search through millions of potential reactions and may generate large volumes of data.  In order to reduce this volume it is advisable to impose Gamow, spin and parity restrictions and specify products and reactants in as much detail as possible.  Even so output may still be considerable.

    Fortunately the operating system comes to the rescue.  ENSAP writes to the standard output device.  Under DOS (and other operating systems) you can redirect the standard output to a file or send it directly through a pipe to another program.  Redirecting the output to a file might be useful for subsequent scrolling using a text editor or similar listing program.  A pipe can be used to sort or search the output (see next section).

    If you are not familiar with a text editor, you can parcel the output into manageable screen-fulls using the /m option.

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    Sorting the generated output

    It may be of interest to examine which reactions are most energetic or have the smallest Gamow suppression factors.  Most operating systems come with a standard utility, sort for ordering ASCII text such as that produced by ENSAP.  For example to sort 235U neutron induced fission reactions one can try:-

    ENSAP n U235 /spg | sort /+53      (Sort by Energy)

    ENSAP n U235 /spg | sort /+67      (Sort by Gamow factor)

    The /+nn parameter tells sort to start sorting the text starting at the specified column.  Unfortunately the versions of SORT supplied with many PC operating system are unable to cope with more than 65 k bytes of text.  However there are a number of faster sort programs without this limitation available free from public domain software suppliers.

     

    Limitations of the Demo version of ENSAP

     

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    ENSAP Version 1.7 dated 2013

    These features are not available in the demo version of ENSAP.

     

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    Disclaimer

    The author has made considerable efforts to ensure accuracy of the database and calculations made by ENSAP but cannot take responsibility for any eventual anomalies.

    The author hereby disclaims all warranties relating to the Product, whether express or implied, including without limitation any implied warranties of merchantability or fitness for a particular purpose.  Neither the author  nor any distributor shall be liable for any special, incidental, consequential, indirect or similar damages due to program malfunction, database inaccuracy or any other reason.  In no event shall the liability of the author for any damages exceed the fee paid for the licence to use the software, regardless of the form of the claim.  The person using the software bears all risks as to the quality and performance of the software.

    Acknowledgements

    We thank the Brookhaven National Laboratory for atomic data, updated 2005, in computer readable format for spin and parity information.

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    References

    C.L. Dunford and R. R. Kinsey, "Nudat System for Access to Nuclear Data. IAEA-NDS-205 (BNL-NCS-65687), IAEA, Vienna, Austria (July 1998).   Information extracted from the NuDat data base, version of 17-Mar-2004, using the PC version of the program NuDat.

    W.J.M.F. Collis "Ensap Software Tool To Analyse Nuclear Reactions", Proc ICCF7, Vancouver. (1998)

    G.Audi, M.Wang, et al., "The Ame2012 atomic mass evaluation (I)", Chinese Physics C36 p. 1287-1602, December 2012.