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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)