Brookhaven Double MP Facility - recent developments and plans for the future

The Brookhaven Tandem Van de Graaff facility consists of two model MP accelerators which have been extensively modified and improved over the years. Recent accelerator developments leading to a maximum terminal voltage of 16.5 MV for one of the machines include an increase of the active length of the acceleration tubes, installation of vacuum pumps at intermediate field-free sections, installation of smooth high-voltage-terminal shields and the implementation of a system for individual acceleration-tube conditioning. A new cylindrical voltage-divider resistor-shield arrangement has been tested and will be installed. A novel 4-stage mode of operating the tandems provides variable low-energy highly-charged heavy ions used for atomic-physics experiments. This type of operation has been improved by the addition of a removable gridded lens at the exit of the last acceleration tube. Plans for the future include the production of relativistic heavy ions by injecting beams from the tandems into the AGS 30-GeV proton accelerator at BNL either directly or via a tandem booster cyclotron. For this purpose, a high-intensity pulsed-beam system was developed and tested