ISOLTRAP
Encyclopedia
ISOLTRAP is a tandem Penning trap
mass spectrometer at the On-Line Isotope Mass Separator
at CERN
, very similar to SMILETRAP
. The facility plays a leading role in the field of high precision mass spectrometry of radioactive ions. The masses of more than 200 short-lived nuclides have been measured with a relative uncertainty of typically dm/m ~ 1x10-7 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 ~1x10-8. 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.
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.
Penning trap
Penning traps are devices for the storage of charged particles using a homogeneous static magnetic field and a spatially inhomogeneous static electric field. This kind of trap is particularly well suited to precision measurements of properties of ions and stable subatomic particles which have...
mass spectrometer at the On-Line Isotope Mass Separator
On-Line Isotope Mass Separator
The On-Line Isotope Mass Separator, also known as the ISOLDE Radioactive Ion Beam Facility, is a facility located at CERN on the PS Booster...
at CERN
CERN
The European Organization for Nuclear Research , known as CERN , is an international organization whose purpose is to operate the world's largest particle physics laboratory, which is situated in the northwest suburbs of Geneva on the Franco–Swiss border...
, very similar to SMILETRAP
SMILETRAP
SMILETRAP is a Penning trap mass spectrometer located in Stockholm, Sweden. The name is an acronym, which stands for Stockholm-Mainz-Ion-LEvitation-TRAP....
. The facility plays a leading role in the field of high precision mass spectrometry of radioactive ions. The masses of more than 200 short-lived nuclides have been measured with a relative uncertainty of typically dm/m ~ 1x10-7 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 ~1x10-8. In particular, a linear radiofrequency quadrupole
Quadrupole
A quadrupole or quadrapole is one of a sequence of configurations of—for example—electric charge or current, or gravitational mass that can exist in ideal form, but it is usually just part of a multipole expansion of a more complex structure reflecting various orders of complexity.-Mathematical...
(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.
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
Standard Model
The Standard Model of particle physics is a theory concerning the electromagnetic, weak, and strong nuclear interactions, which mediate the dynamics of the known subatomic particles. Developed throughout the mid to late 20th century, the current formulation was finalized in the mid 1970s upon...
. Additionally, masses of unstable nuclei are the most critical nuclear physics parameters for reliable nucleosynthesis calculations in astrophysics.