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

104 Ru, 110 Pd, 165 Ho, 166 Er, 186−192 Os, and 194 Pt.In 1971, Cline and Flaum[CLI72] developed the theory of rotational invariants that directly and modelindependentlyrelate observed E2 properties to the intrinsic frame E2 properties. The full potential of thistechnique was not achievable in 1971 due to the paucity of E2 data for the excited states. Clearly multipleCoulomb excitation data was essential to determine a more complete E2 data set useful for this technique.Howeveratthattimemanyinthefield argued that achieving a model independent analysis of multipleCoulomb excitation data was not feasible.1979 - 2006:The first real breakthrough was a model-independent analysis of the Coulomb excitation data for 110 Pdmade at Rochester by Lennart Hasselgren using the codes COULEX plus CEGRY[HAS80]. This tour-de-forceanalysis produced a solution with scientifically interesting implications and provided the proof of principlethat led to the development of GOSIA. Unfortunately there was no practical way to prove the uniquenessof his solution, and the time and effort required to replicate such a manual analysis was impractical. Thusit was suggested to Tomasz Czosnyka that he develop a Coulomb excitation least-squares search code basedon COULEX plus CEGRY to provide a practical way of analysing multiple Coulomb excitation data. Thedevelopment of GOSIA proved to be an enormously satisfying and successful project. The first success ofGOSIA was that it proved that the matrix element set found by the manual analysis for 110 Pd was thecorrect solution. Dr Bodan Kotlinski [KOT84] made recoil-distance lifetime measurements in 110 Pd whichalso confirmed the correctness of the solution found by both the manual analysis and using GOSIA. Inparallel, to the 110 Pd work, the thesis work of Ching-Yen Wu[WU83, WU89, WU91, WU96] involved anexhaustive analysis of the W-Os-Pt nuclei that was used extensively to develop and test the GOSIA code.The success of the above mentioned work achieved two long-sought goals of the Cline group. 1) It provedthat multiple Coulomb excitation can be used to model-independently determine signs and magnitudes offairly complete sets of E2 matrix elements. 2) This set of matrix elements was sufficient for an analysis usingthe model-independent Rotational Invariant technique[CLI72, CLI86] to extract the expectation values ofthe centroids and widths in the intrinsic frame for the E2 properties of low-lying states. 3) The E2 rotationalinvariants provided a powerful probe of collective motion in nuclei in shape-transitional nuclei.The successful development and exploitation of Gosia immediately stimulated a rapid growth in multipleCoulomb excitation work led by the Rochester, Uppsala, Warsaw groups and later the Liverpool group.The GSI based groups also were doing similar Coulomb excitation work at the UNILAC in parallel with us.Initially they developed an analysis code [GRE84] but they eventually switched to the use of GOSIA.GOSIA was modelled on the 1978 version[LEL78, LEL78][BOE84] of the Winther-de Boer code COULEXwhich extended the code to include multipolarities, Eλ with λ = 1, 2, 3, 4, 5, 6 as well as incorporatingtime-saving updates. The γ-ray deexcitation part of the code is based on the Coulomb excitation γ-raydeexcitation code code CEGRY which was developed at Rochester during 1965-75 by Cline, Lesser andTowsley[CLI74]. Significant contributions to the development and testing of GOSIA have been made byadditional collaborators. Dr Alexander Kavka [KAV90] tested and elucidated the validity and impact of thedeorientation effect, plus he developed the γ-ray efficiency calibration code GREMLIN.GOSIA plus the associated quadrupole rotational-invariants program SIGMA were developed in 1980.Since that time three special versions of GOSIA were developed. The first code called GOSIA2 is intendedto handle both target and projectile simultaneous excitation with common normalization coefficients. Thesecond special code, called PAWEL, is a special offspring of GOSIA designed to handle cases where a fractionof the nuclei have an excited isomeric state as the initial state. The third code ANNL was developed byDr Richard Ibbotson[IBB95] and exploits simulated annealing techniques to locate least-squares minima.Tomasz Czosnyka maintained and updated the coding of the GOSIA suite of codes from their inceptionuntil his untimely death in October 2006. The 2006 versions of these codes posted on the Gosia UserGroup website, http://www.pas.rochester.edu/~cline/Gosia/index.html, are the final versions of the codesas developed and maintained by Tomasz Czosnyka.2006 - present::The GOSIA program was written in Fortran 77 and was originally developed to run on a CDC Cyber 175.The available memory limited the the program size to 130,000 of 60-bit words which complicated the codesince it had to be extensively overlaid. From inception in 1980, GOSIA ran with high reliability on manyof the most powerful computers available. However, by the start of the 21 st century the Fortran compilersbecame less forgiving of archaic Fortran77 commands and the mixed 32 bit and 64 bit variables in GOSIA8