Accurate mass measurements of short-lived isotopes with the MISTRAL rf spectrometer

The MISTRAL experiment has measured its first masses at ISOLDE. Installed in May 1997, this radiofrequency transmission spectrometer is to concentrate on nuclides with particularly short half-lives. MISTRAL received its first stable beam in October and first radioactive beam in November 1997. These first tests, with a plasma ion source, resulted in excellent isobaric separation and reasonable transmission. Further testing and development enabled first data taking in July 1998 on neutron-rich Na isotopes having half-lives as short as 31 ms

A MISTRAL spectrometer accoutrement for the study of exotic nuclides

An ion beam cooler has been constructed to adapt the emittance of the ISOLDE rare isotope beam to the acceptance of the mass spectrometer MISTRAL at CERN. Using $^{20,22}Ne^+$ beams with an energy of E$_{beam}$ = 45 keV the transmission through the cooler was measured to be T = 0.25. An analytical model to describe the transmission as a function of the trapping potential is discussed. By fitting this model to the data, the lateral energy distribution of the radially confined ions was determined to be centered at E$_0$ = 1.3(1) eV and to have a width of $\sigma_E$ = 1.6(1) eV

MISTRAL: the beginning of a new mass measurement program at ISOLDE

The MISTRAL experiment is now on-line at ISOLDE. Installed in May 1997, MISTRAL received its first stable beam in October and first radioactive beam in November 1997. These first tests, with a plasma ion source, resulted in excellent isobaric separation and reasonable transmission. Further testing and development enabled first data taking in July 1998 on neutron-rich Na isotopes having half-lives as short as 31 ms. (6 refs)

First results using a new technology for measuring masses of very short-lived nuclides with very high accuracy: the MISTRAL program at ISOLDE

MISTRAL is an experimental program to measure masses of very short- lived nuclides (T$_{1/2}$ down to a few ms), with a very high accuracy (a few 10$^{-7}$). There were three data taking periods with radioactive beams and 22 masses of isotopes of Ne, Na*, Mg, Al*, K, Ca, and Ti were measured. The systematic errors are now under control at the level of 8\TIMES10^{-7}, allowing to come close to the expected accuracy. Even for the very weakly produced $^{30}$Na (1 ion at the detector per proton burst), the final accuracy is 7\TIMES10^{-7}. (15 refs)