Development of low noise amplifier and associated RF switching circuit for the penning ion trap

In this paper we describe the design and development of cryogenic electronic instrumentation required for VECC cryogenic Penning ion trap facility. As a part of the development of cryogenic electronic instrumentation, a low noise amplifier based on Ga As technology is designed and room temperature testing of the amplifier is successfully accomplished. The equivalent input voltage noise density of the amplifier measured at room temperature is found to be in the range of (1.8 ± 0.2)nV/√Hz at the ion trap axial frequency of 63 MHz. Also a cryogenic switching and RC filtering circuit is developed in order to maintain proper switching of RF energy used to excite the motional amplitude of trapped electrons. These RC filtering circuits filter the noise in the DC supply lines. The performance of this circuit board has been tested successfully upto 90K.