coulomb excitation data analysis codes; gosia 2007 - Physics and ...

• When the level scheme (LEVE) or matrix elements (ME) are changed, the following items shouldbe checked. The transition energies and multipolarities defined in LEVE and ME require internalconversion coefficients in OP,YIEL which cover the range of transition energies for each multipolarityintroduced in ME. Note that the level energies are entered in MeV, not keV.• Changes that affect the kinematics (projectile or target species, beam energy, target thickness, scatteringangle ranges, etc.) should be checked for consistency in the EXPT, OP,YIEL and OP,INTGsections. Pay special attention to the selection of the detected particle and whether the projectile scatteringor target recoil angles are being specified in each section, as well as the accompanying kinematicflags (minus signs). Target thickness is specified indirectly through a range of beam energy and stoppingpower data. Stopping powers may need to be updated when the beam energy range is changed,or when the beam or target species is modified.• If one experiment (EXPT) is normalized to another, relative particle-detector normalization constantsmust be entered in OP,YIEL. Inaccuracies in these normalizations will not affect the yield integration(OP,INTG), but they will cause problems in finding the true chi-squared minimum (OP,MINI).The safest approach to avoid introducing errors is to make changes to the input in the smallest possibleincrements, running the code frequently to check for problems. The following troubleshooting notes may behelpful.• Pay special attention to commas and periods; interchanging one for the other causes errors that aredifficult to spot.• Check the auxiliary files created by GOSIA. Occasionally, an overflow will result in “INF” (infinity) or“NaN” (not a number) being written into a file such as TAPE 4 (the correction factor file). This maycause problems later, when GOSIA re-reads the file.• GOSIA will tolerate comments on some lines in the input (after the required fields), but not on others.Putting comments on the wrong line could cause read errors. Refer to the examples in the sampleinputs. When in doubt, do not insert a comment.• If an error occurs when GOSIA reads the input file,itmaybehelpfultoinsertOP,EXIT(tohaltexecution) immediately before another “OP,” command in the input and run it again to determinewhich section contains the problem.• Many integers that are entered in the input file (and in TAPE 3, experimental gamma-ray yields)determine the number of records and fields to follow, or the number of corresponding records in a latersection. Errors are frequently caused by inconsistencies in these numbers and may be indicated bymessagessuchas“UNRECOGNIZEDSUBOPTION,”or Fortran read errors. If errors are suspectedto be caused by a mismatch in the number of records and can not be found by a cursory inspection, itis often helpful to check each line of the input, comparing it to the corresponding manual entry.The following is an example of the above type of error. The execution terminates with this error:invalid integer: read unexpected characterapparent state: unit 5 (unnamed)last format: list iolately reading sequential formatted external IAbortThis is a Fortran (system) error that is not trapped by GOSIA, so the location of the problem is not specified.Running the input again with OP,EXIT inserted immediately after OP,YIEL to halt the execution results inthe same error, but inserting OP,EXIT just before OP,YIEL prevents the error. Hence, the error is somehowrelated to OP,YIEL. The beginning of OP,YIEL looks like this:OP,YIEL0188