Progress with the 2Q-LEBT Facility for the RIA Project
The design goal of 400 kW uranium beam in the Rare Isotope Accelerator (RIA) Driver Linac can be achieved employing a concept of simultaneous acceleration of two charge states. It has been undertaken to build a prototype 2Q-injector of the RIA Driver Linac which includes an ECR ion source, a LEBT and one-segment of the prototype RFQ. The project called the 2Q-LEBT Facility is being developed in the Physics Division of ANL. Currently, the 2Q-LEBT Facility consists of BIE-100 ECR ion source. The reassembly and commissioning of the source has been completed. During the commissioning process we redesigned and manufactured a few components of the source to increase the beam production performance. A new diagnostic station has been designed and built for accurate measurements of the output beam emittance. The further development of the 2Q-LEBT Facility comprises installation of the source on 100 kV high-voltage platform, building an achromatic bending and transport system including the multi-harmonic buncher, and a full power 57.5 MHz RFQ segment. This report includes a detailed description of the 2Q-LEBT design and beam dynamics simulations along with emittance measurements for various beams.
The BIE100 ECR ion source
BIE100, an all-permanent-magnet-based electron cyclotron resonance (ECR) ion source, has been under development at Berkeley Ion Equipment (BIE). With a relatively small but optimized source magnet volume, the maximum peak magnetic field strengths of the BIE100 reach 13 kG on axis and 11 kG at the plasma chamber walls, respectively. Microwaves of frequencies of 12.75 and 14 GHz are to simultaneously heat the plasma electrons. The development goal of this ECR ion source is to further explore the capabilities of ECR ion source in the efficient production of the intermediate and high charge state rare ion beams needed for the generation of rare ion beams and industrial applications. This article will present the design features of the BIE100 ion source and its current status.
Geomagnetic micropulsations due to the motion of ocean waves
When sea waves move in the magnetic field of the earth, electric currents are generated in the water volume. These currents give rise to a small magnetic field which perturbs the earth's field. For plane trochoidal waves, this perturbing field decays exponentially with altitude and lies in a vertical plane which is oriented in the direction of wave propagation. The magnitude of the perturbing field also depends upon the magnitude and dip angle of the earth's field, and upon the height, wavelength, and propagation direction of the sea waves. For north-south waves, sea state 5, and an altitude of 100 feet, the perturbation is of the order of 0.1 gamma.