slide1
Download
Skip this Video
Download Presentation
Challenges on phase transitions and gamma-strength functions Magne Guttormsen

Loading in 2 Seconds...

play fullscreen
1 / 25

Challenges on phase transitions and gamma-strength functions Magne Guttormsen - PowerPoint PPT Presentation


  • 82 Views
  • Uploaded on

Challenges on phase transitions and gamma-strength functions Magne Guttormsen Department of Physics, University of Oslo. Oslo method Thermodynamics Electromagnetic transitions Challenges. Workshop on
Level Density and
Gamma Strength in Continuum, Oslo, May 21 - 24, 2007. E x.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' Challenges on phase transitions and gamma-strength functions Magne Guttormsen' - jaegar


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide1

Challenges on phase transitions and

      • gamma-strength functions
  • Magne Guttormsen
  • Department of Physics, University of Oslo
  • Oslo method
  • Thermodynamics
  • Electromagnetic transitions
  • Challenges

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

slide2

Ex

T = 1 MeV

Spin

2-6 ħ

Spin-energy diagram

Yrast line

(no levels)

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

slide3

M

F0

-

G

M-1

=

1

W

The first generation method

F0

F1

F2

F3

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

slide4

Gamma-ray multiplicity

E

Spin

E

Spin

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

slide5

The Brink Axel hypothesis

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

slide6

Does it work?

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

slide7

Nuclear entropy

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

slide8

canonical - canonical ensemble

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

slide9

Rare-earth region, case erbium

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

slide10

Preliminary

Proton number Z = 50

Neutron Cooper pairs

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

slide11

J.Lee and J.M.Kosterlitz,

Phys. Rev. Lett. 65, 137 (1990)

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

slide12

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

slide13

Heat

bath

Isolated

E

T

T

Boltzmannfactor

S = S0 + S* + S1

Challenges, new thermodynamic

Negative Cv(E) and T(E) Smoothed (up to E = 100 MeV)

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

slide14

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

slide15

Ex

8

5

2

E

First generation

procedure

Axel-Brink

factorization

into  and f

2 4 6 8

2 4 6 8

Simulation tests of the Oslo method

Event-by-event data

generated in Prague

with DICEBOX

Sorted in Oslo into

(Ex, E) matrix

Ex

8

5

2

E

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

slide16

Results from the blind test

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

slide17

Radiative strength functions

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

slide18

Pygmy resonance

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

slide19

Scissors mode

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

slide20

Giant dipole resonance

Kadmenskii, Markushev

and Furman (KMF) model

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

slide21

Unexpected RSF upbend

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

slide22

Upbend in iron

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

slide23

Temperature dependence?

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

slide24

Verifications

Budapest

Research Reactor

(n, ) reaction

INPP, Ohio University

(d,n) reaction

Subatomic and Astrophysics Division Annual Meeting 2007

slide25

Challenges

  • Understand the difference in quantities observed in different experiments
    • Pygmy resonance
    • GEDR-tail match
    • Low energy -strength
  • Spin distribution
  • Parity asymmetry
  • Thermalization
  • -canonical or canonical ensemble - or another theory?
  • Critical T, how to interpret and measure?
  • Single quasi-particle entropy

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

ad