The Beam Transport System (BTS) Group is an Accelerator Support Central Group (AcSCG), which takes care of the BTS instruments of all the accelerators and associated experimental facilities at IUAC. The group is responsible for the design, manufacture, operation, and maintenance of accelerator magnet power supplies and other BTS-associated instruments. The primary duty of the group is to perform yearly preventive maintenance of the BTS-associated instruments to achieve maximum uptime with the best performance. To achieve the throughput, the laboratory personnel work as a 24 x 7 on-call team, investigate beam stoppages attributable to the power supplies and strive to minimize the repair time. More than 150 Magnet Power Supplies (MPS) are in operation, which constitutes the main sub-system of the BTS instruments. These are highly-regulated (10 ppm to 50 ppm) current sources ranging in output from 10 A to 600 A and output power ranging from a few hundred watts to 60 kW. The regulation technologies currently in use cover several types from linear transistor regulated, Silicon Controlled rectifiers (SCR), and Pulse width Modulation (PWM) with analog regulation control.
Most significantly, almost 50 % of the total magnet power supplies are developed in-house. The in-house development has resulted in easy and fast maintenance and minimizes the import of spare parts. To reduce the types of spares and to simplify maintenance and personnel training, common control electronics are designed for all current ratings of power supplies. The power supplies are designed with flexible arrangements for output currents and whenever possible the same type of unit is used for different current rating magnets to minimize the type of power supply units.
The group is also involved in the design & development of different types of detector bias high voltage (HV) power supplies. All power supplies for germanium detectors (5 kV, 100 µA), ACS detectors (3 kV, 10 mA), and pre-amplifiers used in INGA experimental facility are designed and developed in-house. Customized operational features such as output ramping facility are incorporated in germanium detector bias power supplies to enable simultaneous biasing of detectors of the multi-detector arrays at optimal rate; this has made the biasing exercise safe, easy and fast.
Meanwhile, the group is also involved in developing some key technologies and equipment, such as Piezo-based resonance frequency tuner control for LINAC-QWR, LLRF-based controls for the Multi Harmonic Buncher (MHB), and RF cavities (Radio-Frequency Quadrupole, Drift Tube LINAC, and Spiral Buncher) of the upcoming High Current Injector (HCI) facility. The LLRF controls are servo-type closed-loop controls with customized functionalities to control and regulate the resonance, phase, and field of the HCI-RF cavities.
With long and continuing exposure in preventive and breakdown maintenance of sophisticated beam transport magnet power supplies, the BTS group personnel have developed special repair skills. The group has voluntarily extended this expertise to repair similar instruments for other institutes who approached through the proper channel.