ISOLTRAP Project
Introduction to ISOLTRAP
Accurate mass measurements of short-lived nuclides are of high interest for a number of reasons: They allow direct observation of nuclear structure effects like the location of shell and sub-shell closures, pairing, or the onset of deformation. In combination with a precise study of super-allowed beta emission they provide tests of the standard model. Additionally, masses of unstable nuclei are the most critical nuclear physics parameters for reliable nucleosynthesis calculations in astrophysics.
The tandem Penning trap mass spectrometer ISOLTRAP at the on-line isotope
separator ISOLDE at CERN
/Geneva plays a leading role in this field. The masses
of more than 200 short-lived nuclides have been measured with a relative
uncertainty of typically δm/m ~
1*10-7 and even almost up to one order of magnitude lower in some
special cases. Recently, the performance of the Penning trap mass spectrometer
ISOLTRAP has been considerably enhanced. Major technical improvements were
implemented to increase the range of accessible nuclei to those that are produced
in minute quantities of only 100 ions/s and to nuclei with half-lives down to
~50 ms as well as to decrease the typical relative uncertainty down to
~1*10-8. In particular, a linear radiofrequency quadrupole (RFQ) trap and a
carbon-cluster source were added to the ISOLTRAP spectrometer. Since the unified
atomic mass unit is defined as 1/12 of the mass of 12C
the calibration of the magnetic field with carbon clusters allows absolute mass
measurements.
Please visit the ISOLTRAP website
to read more about the ISOLTRAP experiment
.