Present status and future planning of pulsed electron accelerator program at APPD, BARC

The pulse power technology has wide-ranging applications in industry, defence and research. The parameters of interest in these applications are high voltage (100kV-1MV), high current (1kA-1MA), high energy (100J-5MJ) and short duration (10-100ns) pulses. Generally these systems are used in a single pulse mode with one shot in 1 to 5 minutes for most of the research applications. But for industrial applications and accelerators, these systems have to be repetitively pulsed in the range of a few pulses per minute to a few kHz. This may be continuous or in bursts of a few pulses, involving a high repetition rate for a short period. These bursts are single or repetitive in nature. APPD, BARC, Mumbai has been working in the field of pulse power systems for the development of relativistic electron beams (REB). A few pulse power systems have been built and are been used for research in Relativistic Electron Beam (REB) generation and its applications, in a single pulsed mode with one shot in 1-2 minutes like (i) KALI- 75, rated 0.3MV, 2kA, 60ns, (ii) KALI-200, rated 0.3MV, 20kA, 50ns, (iii) KALI-1000, 0.3MV, 30kA, 100ns and (iv) KALI-5000, rated 1 MV, 40kA, 100ns and (v) 200keV, 5kA, 50ns, Induction Linac for 10-100 Hz repetitive operation. The important applications are (i) Flash X-rays generation (FLX), (ii) High Power Microwave (HPM), (iii) Pulsed Neutron Sources (PNS) and (iv) Pulsed Ion Sources. The KALI-200 and KALI-1000 system are based on Tesla- transformer principle which is set to double resonance to achieve higher transfer efficiency and use castor oil/deminaralized water as dielectric in transmission line.The KALI-75 is based on PFN Marx generator principle and KALI-5000 is based on Marx-Blumlein principle, where the output voltage is same as the charging voltage. The need for stepping up energy production to keep pace with the ever increasing demand is universally recognized. To meet the future energy demands and based on the expertise available with us, the development of TeraWatt level pulsed power systems are being proposed during the XIth plan viz. (i) a single shot pulse power system of 3MV, 350kA, 100ns, 1 TW ratings based on plus-minus charging type Marx generator combined with demineralized water filled Blumlein and SF6 filled spark gap switches and (ii) Linear Induction Accelerator rated 1 MeV, 5kA, 100ns, 10-1 kHz. Relatively low voltage (75-200kV) fed cavities give the flexibility to address a variety of applications in a multi-module system, for FXR usage in dynamic imaging with advanced instrumentation. The experimental set-up, schematic circuit diagram, the results, discussions and conclusions are presented in this paper. (author)