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Orozco, Charles

Publications and source records attributed to Orozco, Charles.

QXF Cold Mass Friction Test

The purpose of this test is to determine the longitudinal force on the stainless steel shell that is required to break the friction between the stainless steel shell and the aluminum shell underneath. This is achieved by suspending the short magnet between two backing plates on the eight grade 8 threaded rods which replace the 8 stainless steel toke tie rods in the magnet assembly. Eight hydraulic cylinders are mounted to each backing plate. Six, 22" sections of the stainless steel shell are welded in place on the magnet, each of which has a slightly different developed length, starting from the baseline design, and becoming progressively looser. A pushing flange is mounted to the stainless steel shells via small tack welds. Four load cells are then attached to the flange at designated points, while additional tooling is attached to each of the cylinders to facilitate the transfer of force from the cylinders to the stainless steel shell During the test, the cylinders will be slowly energized to no more than 7000 psi, with a resultant, longitudinal force on the flange of no more than 125,400 lbf. For each set of shells, the test ends when the load cell monitoring software detects a sharp decrease in force. This will indicate that the friction has broken. The cullenders will then be de-energized and the cycle will repeat for the next test. Welding operations outlined in the procedure (US-HiLumi-doc-4200) are outside the scope of the HA as the work is occurring under a previously-issued burn permit by qualified welders.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Assessment of MQXF Quench Heater Insulation Strength and Test of Modified Design

The HL-LHC interaction region magnet triplets (Q1,Q2, and Q3) will be composed of superconducting Nb 3 Sn quadrupoles. The MQXF quadrupole protection system is based on CLIQ (Coupling-Loss Induced Quench system) and outer layer quench heaters. Furthermore, this paper reports a summary of quench heaters to coil high voltage tests performed on MQXF short and long coils in air after fabrication, and in air and He gas after magnet training. Breakdown voltage values demonstrate good margin with respect to the Electrical design criteria for the HL-LHC inner triplet mag-nets. A modification in the quench heater installation-with an extra layer of fiber glass between the coil and the quench heater trace-has been proposed and tested in a mirror magnet to further increase electrical margins. Results demonstrated improvements of high voltage margin at the expense of a clear increase of hot spot temperature.The baseline heater to coil insulation was assessed to be able to guarantee safe operation for the Nb 3 Sn quadrupole magnets for the interaction regions of HL-LHC.

43 PARTICLE ACCELERATORS↗