1. 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 , 2007

2. 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 , 2007

3. 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 , 2007

4. Gamma-ray multiplicityE
Spin E
Spin
Workshop on
Level Density and
Gamma Strength in Continuum, Oslo, May , 2007

5. The Brink Axel hypothesis
-First generation at Ex
-Bell-like shape
-Two factors
Workshop on
Level Density and
Gamma Strength in Continuum, Oslo, May , 2007

6. Does it work? -Surprisingly well -2 functions for all spectra
Workshop on
Level Density and
Gamma Strength in Continuum, Oslo, May , 2007

7. 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 , 2007

8. canonical - canonical ensemble
Workshop on
Level Density and
Gamma Strength in Continuum, Oslo, May , 2007

9. Rare-earth region, case erbium
Workshop on
Level Density and
Gamma Strength in Continuum, Oslo, May , 2007

10. Preliminary Proton number Z = 50 Neutron Cooper pairs
- First application
Workshop on
Level Density and
Gamma Strength in Continuum, Oslo, May , 2007

11. - 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 , 2007

12. Workshop on
Level Density and
Gamma Strength in Continuum, Oslo, May 21 - 24, 2007

13. 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 , 2007

14. 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 , 2007

15. Simulation tests of the Oslo method
Event-by-event data
generated in Prague
with DICEBOX
Sorted in Oslo into
(Ex, E) matrix 2 5 8 Ex E Ex 8
First generation
procedure
Axel-Brink
factorization
into  and f 5 2 E
Workshop on
Level Density and
Gamma Strength in Continuum, Oslo, May , 2007

16. Results from the blind test
Workshop on
Level Density and
Gamma Strength in Continuum, Oslo, May , 2007

17. Radiative strength functions
Workshop on
Level Density and
Gamma Strength in Continuum, Oslo, May , 2007

18. Pygmy resonance
Workshop on
Level Density and
Gamma Strength in Continuum, Oslo, May , 2007

19. Scissors mode
Workshop on
Level Density and
Gamma Strength in Continuum, Oslo, May , 2007

20. Giant dipole resonance
Kadmenskii, Markushev
and Furman (KMF) model
Workshop on
Level Density and
Gamma Strength in Continuum, Oslo, May , 2007

21. 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 , 2007

22. Upbend in iron
Workshop on
Level Density and
Gamma Strength in Continuum, Oslo, May , 2007

23. Temperature dependence?
Workshop on
Level Density and
Gamma Strength in Continuum, Oslo, May , 2007

24. Verifications Budapest Research Reactor (n, ) reaction
INPP, Ohio University
(d,n) reaction
Subatomic and Astrophysics Division Annual Meeting 2007

25. 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 , 2007