Abstract Details
| Name: Saurabh Neema Affiliation: Bhabha Atomic Reseach Centre, Mumbai Conference ID: ASI2017_812 Title : Design and Development of Camera Electronics for MACE telescope Authors and Co-Authors : S.K.Neema1, S.S.Sikder1, K.Jha1, Saju Joy1, A.Manna1, Anita B.1, J Hariharan2, Preetha M. Nair1, Shikha Srivastava1, Anushri Jain1, Padmini S.1 Abstract Type : Poster Abstract Category : Instrumentation and Techniques Abstract : The MACE (Major Atmospheric Cherenkov Experiment) telescope with a light collector diameter of 21 m, is being set up at Hanle (32.80 N, 78.90 E, 4200m asl) India, to exploring the gamma-ray sky at energies down to 20 GeV. The imaging camera of the telescope comprises 1088 pixels. The entire camera electronics is mounted on the camera with only the power and communication cables connected to ground station. Instrumentation consists of 68 Camera Integrated Modules (CIM) with 16 channels each and backend electronics consisting of Central Camera Controller (CCC), Data Concentrator (DC) and Second Level Trigger Generator (SLTG). The photomultiplier gains are matched by the programmable high voltage. Each PMT anode signal is coupled to a high bandwidth preamplifier, a dual gain amplifier, discriminator and a scalar. Individual CIM module has its signal processing electronics, first level trigger generation logic and signal digitization circuitry built into it. An analog switched capacitor array is used as a ring sampler operating at 1GSPS for continuous digitization of the photomultiplier signals. In order to ensure a wide dynamic range, each photomultiplier signal is simultaneously amplified by a low gain and a high gain amplifier. To reduce the volume of data, 1GSPS pulse profile information is stored only for those channels which have been triggered while the integrated charge content is stored for the all channels. The instrumentation has been custom designed with innovative techniques to achieve low power, small size, light weight and high performance in terms of low noise, high bandwidth and high event rates. A GPS synchronized master clock is used to generate globally synchronized time stamp for the acquired events. A two stage trigger system generates event trigger based on nearest neighbour close cluster configuration. The system health parameters such as High Voltage, Discrimination Threshold, Anode Current, Single Channel Rates, Chance Coincidence Rates, Power Supply status, Module Temperature etc are monitored at regular interval to ensure stable operating conditions. The anode current is limited in hardware as well as corrective action is taken within CIM to limit anode current to ensure safety of PMTs. The ground based control room, houses operator console and Data Archival system to provide interface to the camera and data saving respectively. The basic architecture and salient features of the camera instrumentation for the MACE telescope will be presented in this meeting. |