Thursday, June 22, 2006

Install Gamma High Voltage Power Supplies in Main Control Rack

In preparation for installing the three gamma power supplies in the main control rack, the diagnostics patch panel was moved to be at the top of the rack containing the two Tektronix 2024 scopes. The System Control Unit (R01), Gas Processor Control Unit (R04), and the Vacuum Gauge Controller Unit (R05) were moved toward the bottom of the main control rack. The High Voltage Control Unit (R03) was removed along with its associated shielded “gray cube” box that contained the previous Main Charging control electronics. All unused control and coaxial cables were removed between the main control rack, the Pulse Modulator HV Power Supply (M03), the X-ray Anode High Voltage Unit (M05A), and the X-ray Anode HV Tank (MO5B). Three Gamma power supplies were then mounted in the main control rack and additionally supported on rails. Although not necessary, a space of 1.75” was left between the power supplies for more than adequate cooling and ease of installation. The X-ray Anode Gamma power supply was connected to the X-ray Anode HV Tank via a 100-foot Dielectric Sciences (DS-2124) coaxial charging cable. This cable is polyethylene based with a graded semicon center shield robustly rated for 100 kV DC. The other two Gamma supplies were connected to a new dual charging board (described later) via similar 34-foot long coaxial cables. All three power supplies are supplied by 120 VAC power from three unused legs of the 208 three-phase Main Power Interconnect Box (M00). The power requirements of each supply are 7 amps at 120 VAC. Appropriate circuit breakers are now on hand and need to be installed in the future. The fourth Gamma power supply that had damaged current and voltage meters during shipment to UIC was repaired with parts from Gamma High Voltage Research and tested; this power supply should be used as a direct replacement spare.
(Written by Randy Carlson)

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