1. How do nuclei rotate?
2. High Spin

2. Coincidence measurements
select rotational bands.

4. Stability against fission
Homogenously charged droplet

5. fission instable
fission barrier 8MeV

6. Rotational
bands in
5/17

7. Semiclassics High angular momentum
can be treated as a classical quantity
For uniform rotation the
rotational frequency (angular velocity)
is given by the classical relation

8. Experimental rotational frequency

9. M1 radiation
intensity
also well
described
by classical
radiation
theory
E2 radiation

10. M1 radiation - high spin limitK J

11. Angular momentum, moment of inertia and routhians as functions of the frequency
Long bands permit us to derive the classical functions

12. Includes a quantal correction
Zero point fluctuation I
I+1/2
10/17

14. Rotational bands in the non-adiabatic regime
How are the spectral lines arranged into bands?

15. Rotational
bands in

16. band EAB
band E
bandcrossing

17. Summary
Nuclei can be studied at high spin where intrinsic and rotational motion are on the same time scale.
The levels still organize into rotational bands, the states of which are connected by fast electromagnetic transitions.
Bands cross each other.
High spin allows us to use classical concepts for the rotational degree of freedom.
The angular velocity becomes a well defined concept.
It is very useful to study physical quantities as functions of the angular frequency.