Development of 3-1/8 inch transmission line components for buncher cavity of LEHIPA

In Low Energy High Intensity Proton Accelerator (LEHIPA) the proton beam need bunched before accelerated in a Drift Tube Linac (DTL) to avoid the beam loss due phase spread of ion. A buncher cavity produces the RF gradient in the gaps and bunches the proton beam. To produce the RF gradients in a buncher cavity, it needs a RF power source at 10 kW, 352 MHz. Since the buncher cavity and RF solid-state power amplifier which feeds the cavity are located in separate galleries (i.e klystron tunnel and linac tunnel). This needs a coaxial transmission line in 3 1/8 inch diameter. The transmission line consists of various bends and directional couplers for diagnose the RF transport line. The paper discuss about the design and performance parameters of bends and directional couplers. The simulated and measure results have been presented to evaluate the RF designs. etc. The developed transmission line bend and directional coupler are shown. These components have been characterized using VNA. The reflection loss of a bend is less than 22 dB. The directional coupler has the coupling co-efficient of 53 dB and the return loss of 33 dB. (author)