Alternative Compact LEBT Design for the FAIR Injector Upgrade

In order to provide high intensity and brightness of the uranium beam for the planned FAIR project, the existing High Current Injector (HSI) at GSI has to be upgraded [1]. A part of the upgrade program is the design and construction of a compact straight injection line into the 36 MHz Radio Frequency Quadrupole of the HSI. As an alternative to a conventional LEBT design consisting of magnetic systems such as solenoids or quadrupoles, the application of Gabor lenses has been investigated. The focusing force of the Gabor lens is created by the space charge of an electron cloud, confined by crossed magnetic and electric fields inside the lens volume. Therefore, the Gabor lens combines strong, electrostatic focusing with simultaneous space-charge compensation. In previously performed beam transport experiments at GSI a prototype Gabor lens has been tested successfully. Furthermore, the operation and performance of such a device in a real accelerator environment has been studied. In this contribution an alternative LEBT design will be discussed and an improved Gabor lens design will be presented.