Erzeugung exotischer Atomkerne

Kernfusion in Sternen

Der Ursprung der Elemente

Nukleosynthese nach dem Urknall

Neutroneneinfang in Roten Riesensternen oder Supernovae

Krebsnebel

Supernova beobachtet 1054

M 8M

Roten Riese Weiβer Zwerg

Zwiebelschalenstruktur kurz vor Explosion

Geburt und Tod der Sterne

8M M 15M

Supernova II1.4M Mcore 2M

Neutronen Stern

M 15M

Supernova IIaM 2M

Schwarzes Loch

number of neutrons

nu

mb

er

of

pro

ton

s

Nucleosynthese in Supernova-Explosionen:

Schneller Neutroneneinfang durch instabile (neutronenreiche) Isotope

Fusion in Sternen

Der Ursprung der Elemente

Reaktionsmechanismen zur Erzeugung radioaktiver Strahlen

Protonen-indizierte Reaktionen Schwerionen-induzierte Reaktionen

Fragmentation im Fluge

Ionen-Separation on-line „ISOL“

Zwei moderne Methoden zur Erzeugung und Untersuchung seltener Isotope

Fragmentation „im Fluge“ (IF): Gestoppte und wiederbeschleunigte Ionen„Ionen Separation Online (ISOL):

Relativistische Schwerionenstrahlen Intensive Protonenstrahlen

Dünnes Target:Projektilfragmentation

Fragmentseparator

Speicherring

Heißes, dickes Target:Targetfragmentation

Ionenquelle

Massenseparatorgeringer Auflösungs

Ionenkühlung

Ionenfallen

ms - s

Konzepte für ISOL

Oberflächen-Ionenquelle

ISOLDE (CERN)

Strahl aus dem PS Booster:Verbund aus 4 kleinen Synchrotrons liefert 1 GeV Protonen, 3.21013/s (alle 1.2 s)

Some of the targets used at ISOLDE consist of molten metals kept at temperatures from 700o C and up to about 1400o C. Such targets are characterized by a relatively long release time of the produced isotopes and a typical time constant of the release is about 30 seconds. Faster release times, in the order of one second or less, can be obtained, if target material in the form of refractory metal powder, metals or carbides is used at temperatures above 2000o C. An expected decrease in the release time due to the "shock-wave" effect of the pulsed proton beam has been observed. Time constants down to some tenths of a second can be reached for the fastest targets.

The ISOLDE PS-Booster facility is equipped with two isotope separators. The General Purpose Separator (GPS) is designed to allow three beams, within a mass range of ± 15%, to be selected and delivered to the experimental hall. The magnet is double focussing H-magnet with a bending angle of 70° and a mean bending radius of 1.5 m. The mass resolving power is M/M=2400.

The second separator, the High Resolution Separator (HRS), is equipped with two bending C-magnets with bending angles 90° and 60° degrees, respectively. At the moment one single mass, with a resolution of about M/M=5.000, can be separated routinely with the HRS separator. The calculated beam profiles for the masses 99, 100 and 101 are shown in the figure. It will be possible to achieve a maximal resolution of more than 30.000.

Separatoren an ISOLDE (CERN)

Konzepte für Separation im Fluge

Erzeugung hochgeladener Isotope an der GSI

Beispiel: 78Ni

B - E - B Separation Method

Reichweite und Energieverlust geladener Teilchenin Materie nach Bethe-Bloch

Der Fragmentseparator der GSI

GSI:Kombination von relativistischen Ionenstrahlen, Fragmentseparator und Speicherring (oder Neutronendetektor)