Charge State Separation Research Articles

An Experimental Apparatus for Low Energy High Charge Heavy Ions to Study Collisions on Atomic Hydrogen

The design and performance of a recoil ion source system which includes a recoil ion source, atomic hydrogen thermal oven target and an electrostatic analysis system will be discussed. The recoil ion source produces low velocity highly charged ions via collisions between heavy fast pump beams from the EN tandem accelerator and target gases. Time-of-flight techniques provide initial recoil charge state separation. Collisions of the recoils with atomic hydrogen are being studied. The atomic hydrogen is provided by a thermal oven which features long life time operation and low input power requirements. Dissociation fractions of 80% are achieved for 300 watts of input power. A hemispherical electrostatic analyzer allows the final charge states of the recoil ions to be determined thereby allowing the measurement of charge exchange processes for an energy range of 100 eV/q to 5000 eV/q for the incident recoil ions.

Magnetic quadrupole and solenoidal spectrometers

General optical properties of magnetic quadrupole spectrometers (QS) are reviewed, together with experimental purposes for nuclear physics: background reduction, magnetic rigidity filtering for extreme forward angles measurements, light charged particle discrimination, ionic charge state separation, time of flight mass spectrometry and fast collection of radioactive nuclear reaction products. Possibility of alternative devices such as superconducting quadrupoles or solenoid spectrometers are discussed.

A time-integrated perturbed angular correlation measurement on the first 2 + of 24Mg, using charge state separation

Time-integrated perturbed γ-ray angular correlations on the reaction 24Mg( 32S, 32Sγ) 24Mg have been measured for the 12 +, 11 +, 10 + and 9 + charge states of 24Mg ions in their first nuclear excited state recoiling in vacuum. The incident energy was 67 MeV. In spite of the large value of ( ω 1 s τ = 7.4 ± 0.5, found by Horstman et al., the 11 + perturbed angular correlation was far from the hard-core limit. The analysis showed that less than 50 % of the single-electron ions were in their 1s ground state. The 10 + angular correlation results lead to a zero field configuration (including the ground state) population of (47 +4 −8%). It is found that statistical assumptions do not apply to the populations of the spectral terms 3P 1, 2. The 9 + data can simply be analysed by only considering the ground state (1s) 22s and very weak field configurations. In this case the ground state population has been found to be (53 ± 11) %. Attempts are made to explain the present results with earlier ones.