Using Catkin the relativistic kinematics programme written ...



Using Catkin v2.00 [pic] the relativistic kinematics program in Excel

This document describes the spreadsheet CATKIN written for Microsoft Excel, which performs kinematics calculations for two-body collisions as well as calculating various other nuclear physics quantities such as: separation energy, Q-value, multiple scattering, Brink matching, safe Coulomb energies, breakup cone sizes, etc. The document requires nothing other than a copy of Excel on your computer.

A general feature is that cells where you enter values are coloured yellow. All other cells in the spreadsheets are protected, so that you cannot accidentally change a formula, etc. Using the ‘tab’ key will automatically move you to the next yellow (data entry) cell.

The two spreadsheets into which you may enter data are: (1) kinematics (where you specify a two-body reaction and the kinematics are calculated), and (2) Calculator (where several additional nuclear physics quantities can be calculated). Several other sheets and charts display kinematics plots. A final sheet holds the mass excess data read in from the Audi web site, and can be updated (see Appendix).

The main two-body reaction spreadsheet is called kinematics and it has several parts

□ The input and reaction summary section

(columns B to O, rows 1 to 10)

□ A self-contained table of solutions for a specific range of angles

(columns B to S, rows 13 to 26)

□ A complete set of solutions from 0 to 180 degrees (1 degree steps)

(columns B to S, rows 30 to 210)

□ A set of columns containing intermediate computational values

(columns U to AN) which are of no general interest.

In the reaction entry section, the cells for input are coloured a light yellow/orange colour. The recoil is labelled light turquoise and the programme works it out from the beam, target and ejectile.

The beam, target and ejectile are specified by their chemical symbol (lower or upper case are acceptable) and the mass number. A mass table on a separate sheet (2000 data) is used to calculate the reaction Q-value and the mass excesses etc.

The other inputs apart from these three particles are the beam energy in the lab, and the excitation energy of the recoil nucleus. There is no facility for explicitly including excitation in the ejectile.

The section where a table gives results for a particular range of angles is given below the input information. Here, the initial angle and the step in angle are specified for the ejectile. The programme uses 11 angles separated by the given step.

Everything else should update automatically. If it doesn’t for some reason, it is possible to force a recalculation in Excel using Tools>Options>Calculation>CalcNow.

Under the font and to the left of the equals sign there is a drop-down list that includes the option Print_table. Selecting this will highlight the top region of the sheet, and this area can be printed on its own by using File>Print and checking selection, then Preview>Setup>Page and check fit to page and landscape and click OK, and the Print or Close depending on whether the print is to proceed.

The summary plots chart includes plots of various quantities derived from the results section in rows 16 to 26. There are 4 plots for each of the two possible kinematic solutions.

The lab angle vs cm chart gives a single plot of the function relating the laboratory and centre of mass angles for ejectile and recoil, cm angle 0 to 180 degrees.

Lab energy vs cm gives the analogous plot for ejectile and recoil energy, for 0 to 180 degree cm angles.

The plectrum plots are plots of lab energy vs lab angle, for the reaction specified in the kinematics sheet. (I call them by this name, because they have the characteristic shape of a guitar plectrum in the case of reactions that ‘fold around’ to give two solutions at forward angles).

The Calculator spreadsheet will calculate the quantities Mass, Separation energy, Q-value, B(, momentum, experimental production rates, Coulomb barriers and safe energies, breakup cone sizes, Brink cluster transfer matching and multiple scattering angles. At the top of the sheet, hyperlinks allow the desired part of the sheet to be easily reached in one click.

The mass table is self explanatory and contains the mass excess data and the plotting sheet is simply a scratch pad of intermediate computations.

Installation of catkin on your computer

To install, copy the files catkin2.00(Excel), Shortcut to catkin2.00 (shortcut) and kin-icon3 (icon file) to a folder called kinematics that should be created in the My Documents folder on the C: drive. The shortcut can, if desired, be dragged onto the desktop (background screen area) for quick access to the kinematics spreadsheet by double clicking. Shortcuts can be created by highlighting a file and clicking File>CreateShortcut, and icons can be associated/changed by highlighting the shortcut and using File>Properties>Shortcut>ChangeIcon, but these steps should not be necessary if the kinematics folder is used as above. Well, at least that was the situation on my computer; any adjustments for a different operating system etc. Should hopefully be fairly minor.

Good luck!

Wilton Catford, 29 April 2002

W.Catford@surrey.ac.uk www fax: 0044 (0)1483 686781 Physics Department, Surrey, UK

Development history of catkin the relativistic kinematics spreadsheet in excel

|Date |Version |Initials |Mod |Comments |

|19 Apr 99 |1.01 |WNC | |Initial release (several |

| | | | |copies only, for trial) |

|12 May 99 |1.02 |WNC |radians/degrees error fixed in recoil angles | |

| | | |2nd soln recoil angle formula fixed | |

| | | |plectrum plots added | |

|21 May 00 |1.10 |WNC |Allow to download Audi mass table |Development version |

| | | |Calculator spreadsheet added |only |

|29 Apr 02 |2.00 |WNC |Calculator spreadsheet completed |First open release |

|6 Aug 02 |2.00 |WNC |Macro for multiple scattering added |First web release |

| | | | | |

| | | | | |

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| | | | | |

Catkin, noun. A unisexual inflorescence, consisting of rows of apetalous flowers ranged in circles along a slender stalk; the whole forming a cylindrical, downy-looking, and generally pendant part, which falls off in a single piece after flowering or ripening; as in the willow, birch, poplar, pine, hazel, etc. (Oxford English Dictionary)

Appendix

Mass Table Downloading

Go to the mass table at

and then click for Atomic Mass Evaluation (AME) and go to the files for, e.g., AME 1995 evaluation.

Download the file that is the upgrade of mass_rmd.mass95 to your disk

(suppose that this is called mass_rmd.massNN; it will appear on file lists as mass_rmd without its extension, so beware of confusion).

Save a copy of the kinematics spreadsheet with its original mass table as a backup, in case of mistakes.

Select the mass table, i.e. the sheet mass_rmd.mass (you will need to unprotect it, using

Tools>Protection>Unprotect sheet and the password masses as prompted at the top of the sheet).

Highlight (select) the part-row A8:F8 in this sheet

With the “shift” key held down, double click on the bottom perimeter line of the highlighting

This should result in the whole mass table (columns a through F) being highlighted

Select (Edit > Clear > All) to delete this whole area

Get rid of the extra mass added at the bottom by the following step:

Select the cell C7 (“A”) and double click on the bottom highlight line, to get to the added mass at the bottom

Select the added mass cell, and delete its contents (hit backspace and tab)

Select A8

File > Open > mass_rmd (double click) >

Scroll down to first row of actual values (row 40, in the 1995 mass_rmd.mass95 file)

Check that EXCEL recognises that this is a file with “fixed width” fields

Using the arrows or otherwise, set the start row to the correct value (40 in the 1995 case)

Click Next

Click just below the column numbers at the right places to create column divisions between the data fields, for column up to and including the error on the mass excess. Take some time scrolling up and down the file, to ensure that no minus signs etc. end up on the wrong side of the dividers.

Click Next

Set the first column as “do not import” and select second column by clicking at its top header

Set all columns except the following to “do not import” i.e. “skip”; the columns to keep are N, Z, A, EL and the two columns for the Mass Excess and its error. Remember to scroll sideways to check any columns to the right as “skip”.

Click Finish to produce a new spreadsheet with the imported data

Select the first row, columns A through F

Hold shift and double click on the bottom of the selected region to select all the data

Click on the copy icon, or Edit>Copy

Click on underscore at the top of the SPREADSHEET window, to shrink the spreadsheet (not the whole EXCEL window), and then open up the catkin spreadsheet

You should be back in the mass spreadsheet, with the pointer at cell A8

Select the paste icon, or Edit>Paste to paste in all of the new data

Select the top cell in the column of mass numbers (1 for the neutron)

Double click on the bottom of the cell, to go to the bottom of the list

Add one more mass, at a higher value, at the end of the list, to make the lookup procedure work for the last mass in the table.

The last column of the spreadsheet (i.e. column G, labelled “mass excess to use”) should appear automatically. All it does is strip the trailing # from the end of the unmeasured values.

Go back up to the top of the sheet and edit the symbol for the neutron so that it is “nn” instead of “n”, which is necessary to distinguish it from Nitrogen in a case-insensitive manner.

Note that the name of the mass sheet MUST stay as mass_rmd.mass for lookup functions in the calulator sheet to work.

Save the EXCEL file by File>Save or SaveAs to produce your updated kinematics sheet.

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