Hamid Rahimpour; HamidReza Mirzaei; Masoomeh Yarmohammadi Satri
Abstract
A high-power solid-sate based radio frequency power source is introduced in this paper. Solid-state based amplifiers are much more efficient than microwave tubes and can be used in compact electron cyclotron resonance (ECR) ion sources. A reliable negative bias voltage controller is proposed to drive ...
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A high-power solid-sate based radio frequency power source is introduced in this paper. Solid-state based amplifiers are much more efficient than microwave tubes and can be used in compact electron cyclotron resonance (ECR) ion sources. A reliable negative bias voltage controller is proposed to drive the power source's main power amplifier, which can deliver up to 300-watt power to the ion chamber. The selected high-power transistor is internally matched on the input side but the output side is matched in this paper to deliver maximum power to the load. The bias circuit was fabricated on FR4 substrate and measurement results were obtained to verify the functionality of the bias sequencer. Analog simulations were done by LTSPICE and high-frequency simulations are performed with the momentum RF simulator of Advanced Design System (ADS). The output power of the proposed structure is tunable with 0.5 dB resolution and can deliver 300 mW to 300 W power to the ion chamber.
Oveis Hasanpour; Fereydoun Abbasi Davani; Farshad Ghasemi; Mahdi Aghayan; Mohammad Nazari; Shahin Sanaye Hajari
Abstract
Two main insulating gases of SF₆ and N₂/CO₂ mixture are employed to increase voltage capability of electrostatic accelerators. SF₆ offers more insulating capability, but environmental and technical disadvantages of SF₆ makes usage of N₂/CO₂ mixture a desirable option. This paper aims to ...
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Two main insulating gases of SF₆ and N₂/CO₂ mixture are employed to increase voltage capability of electrostatic accelerators. SF₆ offers more insulating capability, but environmental and technical disadvantages of SF₆ makes usage of N₂/CO₂ mixture a desirable option. This paper aims to replace SF₆ with N₂/CO₂ in design of a 500 kV/30 mA parallel-fed voltage multiplier. High-voltage section of the accelerator is a capacitive structure which in combination with rectifying elements, generates the accelerating high-voltage. The structure which is called Voltage Multiplier Capacitive Structure (VMCS) is designed and analyzed in this paper. The first structure is designed to employ SF₆ as insulating gas (VMCS500). Then, the structure is modified to be capable of using N₂/CO₂ as insulating gas with lower breakdown voltage (VMCS500-m). The modified structure requires more complex mechanical manufacturing process, but offers the simplicity of using N₂/CO₂ mixture, the option of using the modified structure with superior SF₆ gas, increasing the output voltage and beam energy. CST EM STUDIO was used for capacitance calculation and electric field analysis. LTSPICE was used for equivalent circuit analysis of the high voltage generating section.