New corrector system for the Fermilab Booster
We present an ambitious ongoing project to build and install a new corrector system in the Fermilab 8 GeV booster. The system consists of 48 corrector packages, each containing horizontal and vertical dipoles, normal and skew quadrupoles, and normal and skew sextupoles. Space limitations in the machine have motivated a unique design, which utilizes custom wound coils around a 12 pole laminated core. Each of the 288 discrete multipole elements in the system will have a dedicated power supply, the output current of which is controlled by an individual programmable ramp. This paper describes the physics considerations which drove the design, as well as issues in the control of the system.
The Fully Digital Controlled Corrector Magnet Power Converter with a Shunt as a Current Sensing Component
In Taiwan light source (TLS), Bira’s MCOR30 power converter modules are adopted as the corrector magnet power converters, the output is regulated by analog PWM IC that caused nonlinear behavior at zero cross and the adjustment of compensator for different kind of magnet load is inconvenient. To fulfill digital regulation control, the analog regulation IC of Bira’s MCOR30 is replaced by a fully digital regulation control circuit. With plugging the homemade fully digital regulation control card into MCOR30 that the current sensing component is a shunt that save cost of the power converter, the switching losses and output current ripple were reduced and stability of output current is improved. With the fully digital regulation control circuit, the parameters of the compensator for different magnet load are very easy to adjust. In addition, the feasibility and validity of MOSFET switching algorism is simulated with MATLAB Simulink and the performance of this power converter is verified, the output current ripple of this power converter could be within 10ppm, which is beyond the requirement of current TLS corrector power converter and qualified to be used in the future TPS facility.
An analytical approach to the design of electrodes in high-power, fast-transverse-flow CO2 lasers
Abstract Usually, the design of the electrodes of fast-transverse-flow CO 2 lasers relies more on experimental data than on theoretical analysis. Traditional systems sustain a stable, high-power discharge but the current distribution generates a peaked, non-uniform small-signal-gain pattern. We present a theoretical model suitable for the design of electrodes that achieves a quasi uniform gain distribution. The analysis, based on a two-temperature model and the gas-transport equations, computes the electron density that supports a flat gain pattern. Combining the desired electron density with the electron-balance equations, the model determines the required electric field. The results were used to design a new set of electrodes for a home-made fast transverse flow CO 2 laser. A stable, large volume discharge ( 4 × 8 × 90 cm 3 ) with very good uniformity was obtained. The resulting gain distribution was registered in a bi-dimensional map. The peak gain rose from 1.2 m - 1 , attained with the old electrode set, to 1.6 m - 1 with the new one and the gain showed a homogeneous profile.