Metallic beam developments for the SPIRAL 2 project

Abstract

The SPIRAL 2 facility, currently under construction, will provide either stable or radioactive beams at high intensity. In addition to the high intensity of stable beams, high charge states must be produced by the ion source to fulfill the RFQ LINAC injection requirements: Q/A = 1/3 at 60 kV ion source extraction voltage. Excepting deuterons and hydrogen, most of the stable beam requests concern metallic elements. The existing 18 GHz electron cyclotron resonance ion source (ECRIS) Phoenix V2 designed at LPSC Grenoble has been used for the tests and will be the source for the SPIRAL 2 commissioning. The tests performed at LPSC for calcium ((40)Ca(14+) and (40)Ca(16+)), nickel ((58)Ni(19+)), and sulfur ((32)S(11+)) are described and discussed. Due to the very high charge states required, the oven method has been chosen. An intensity of 1 pμA has been reached for those elements. The performance and the beam stability have been studied using different buffer gases, and some ionization efficiency preliminary results are given.

Angular distribution measurement of atoms evaporated from a resistive oven applied to ion beam production

“…emitted by the oven was measured as a function of 𝜃 at T=848, 873 and 898 K (see protocol (1) in Fig. 3).…”

“…In our case, the crucible has 2 characteristic lengths and hence two Knudsen numbers: 𝐾 𝑖 = 𝜆 𝑑 1 with 𝑑 1 = 5 mm for the main cylinder and 𝐾 𝑖𝑖 = 𝜆 𝑑 2 with 𝑑 2 = 1 mm for the crucible exiting channel. In this latter case, we considered the mean pressure in the exit channel 1 2 (𝑃 + 𝑃 0 ) to calculate 𝜆. The evolutions of 𝜆, 𝐾 𝑖 and 𝐾 𝑖𝑖 are proposed as a function of 𝑇 and 𝑃 in the table 5.…”

“…This work is dedicated to the study of a low temperature metallic oven dedicated to calcium beam production at the SPIRAL2 facility at GANIL, France [1,2]. The motivation of the study is to better understand the physics and chemistry of such an oven with the ultimate goal to improve the global conversion efficiency of rare and expensive isotope atom (like 48 Ca) to an ion beam in Electron Cyclotron Resonance Ion Source (ECRIS).…”

Angular distribution measurement of atoms evaporated from a resistive oven applied to ion beam production

“…This work is dedicated to the study of a low temperature metallic oven dedicated to calcium beam production at the SPIRAL2 facility at GANIL, France [1,2]. The motivation of the study is to better understand the physics and chemistry of such an oven with the goal to improve the global conversion efficiency of rare and expensive isotope atom (like 48 Ca) to an ion beam in Electron Cyclotron Resonance Ion Source (ECRIS).…”