Challenges on phase transitions and gamma-strength functions Magne Guttormsen Department of Physics, University of Oslo Oslo method Thermodynamics Electromagnetic transitions Challenges -Thank the organizing committee for giving me the opportunity to present work from the Oslo Cyclotron -To day new concept -Could turn out to be as important as spin alignment rot. nuclei Workshop on Level Density and Gamma Strength in Continuum, Oslo, May 21 - 24, 2007
Spin-energy diagram Ex T = 1 MeV Spin 2-6 ħ Yrast line (no levels) Workshop on Level Density and Gamma Strength in Continuum, Oslo, May 21 - 24, 2007
The first generation method - = F0 G W M M-1 1 F0 F1 F2 F3 Workshop on Level Density and Gamma Strength in Continuum, Oslo, May 21 - 24, 2007
Gamma-ray multiplicity E Spin E Spin Workshop on Level Density and Gamma Strength in Continuum, Oslo, May 21 - 24, 2007
The Brink Axel hypothesis -First generation at Ex -Bell-like shape -Two factors Workshop on Level Density and Gamma Strength in Continuum, Oslo, May 21 - 24, 2007
Does it work? -Surprisingly well -2 functions for all spectra Workshop on Level Density and Gamma Strength in Continuum, Oslo, May 21 - 24, 2007
Nuclear entropy -Make entropy from multiplicity of states -See how similar, 2 extra blocked with no entropy -Odd is particle/hole -Outside a hot core with many q.p.!!! Workshop on Level Density and Gamma Strength in Continuum, Oslo, May 21 - 24, 2007
canonical - canonical ensemble Workshop on Level Density and Gamma Strength in Continuum, Oslo, May 21 - 24, 2007
Rare-earth region, case erbium Workshop on Level Density and Gamma Strength in Continuum, Oslo, May 21 - 24, 2007
Preliminary Proton number Z = 50 Neutron Cooper pairs - First application Workshop on Level Density and Gamma Strength in Continuum, Oslo, May 21 - 24, 2007
- First application J.Lee and J.M.Kosterlitz, Phys. Rev. Lett. 65, 137 (1990) - First application Workshop on Level Density and Gamma Strength in Continuum, Oslo, May 21 - 24, 2007
Workshop on Level Density and Gamma Strength in Continuum, Oslo, May 21 - 24, 2007
Challenges, new thermodynamic Isolated E Heat bath T Negative Cv(E) and T(E) Smoothed (up to E = 100 MeV) T Boltzmann factor S = S0 + S* + S1 Workshop on Level Density and Gamma Strength in Continuum, Oslo, May 21 - 24, 2007
Radiative strength function (RSF) Photon strength function (PSF) Loved child, many names Radiative strength function (RSF) Photon strength function (PSF) Gamma-ray strength function Workshop on Level Density and Gamma Strength in Continuum, Oslo, May 21 - 24, 2007
Simulation tests of the Oslo method Event-by-event data generated in Prague with DICEBOX Sorted in Oslo into (Ex, E) matrix 2 4 6 8 2 5 8 Ex E Ex 8 First generation procedure Axel-Brink factorization into and f 5 2 2 4 6 8 E Workshop on Level Density and Gamma Strength in Continuum, Oslo, May 21 - 24, 2007
Results from the blind test Workshop on Level Density and Gamma Strength in Continuum, Oslo, May 21 - 24, 2007
Radiative strength functions Workshop on Level Density and Gamma Strength in Continuum, Oslo, May 21 - 24, 2007
Pygmy resonance Workshop on Level Density and Gamma Strength in Continuum, Oslo, May 21 - 24, 2007
Scissors mode Workshop on Level Density and Gamma Strength in Continuum, Oslo, May 21 - 24, 2007
Giant dipole resonance Kadmenskii, Markushev and Furman (KMF) model Workshop on Level Density and Gamma Strength in Continuum, Oslo, May 21 - 24, 2007
Unexpected RSF upbend Also observed in: Mo, V, Sc, Ni, Ti Physics News Update Voinov et al., Physical Review Letters,1 October 2004. Also observed in: Mo, V, Sc, Ni, Ti (3He, 3He) and (3He, 4He) reactions Workshop on Level Density and Gamma Strength in Continuum, Oslo, May 21 - 24, 2007
Upbend in iron Workshop on Level Density and Gamma Strength in Continuum, Oslo, May 21 - 24, 2007
Temperature dependence? Workshop on Level Density and Gamma Strength in Continuum, Oslo, May 21 - 24, 2007
Verifications Budapest Research Reactor (n, ) reaction INPP, Ohio University (d,n) reaction Subatomic and Astrophysics Division Annual Meeting 2007
Challenges -canonical or canonical ensemble - or another theory? Critical T, how to interpret and measure? Single quasi-particle entropy Understand the difference in quantities observed in different experiments Pygmy resonance GEDR-tail match Low energy -strength Spin distribution Parity asymmetry Thermalization Workshop on Level Density and Gamma Strength in Continuum, Oslo, May 21 - 24, 2007