110 likes | 119 Views
Booster Collimator Review March 17, 2003 Peter Kasper. Goals of the Review. Physics: Will the system be able to do what we want it to? Radiation: Have we properly addressed all the radiation issues? Thermal stresses: Will it melt or pull itself apart?
E N D
Goals of the Review • Physics: Will the system be able to do what we want it to? • Radiation: Have we properly addressed all the radiation issues? • Thermal stresses: Will it melt or pull itself apart? • Mechanical: Is the mechanical design sound? • Electrical and controls: Is the electronic design sound? • Installation and maintenance: Can we build and maintain it? • Project: Are our cost and schedule estimates reasonable? • What have we missed?
Review Agenda • Overview and Background Info. (Peter Kasper ~10 min) • Physics and Radiation (Nikolai Mokhov ~30 min) • Thermal Calculations (Alex Chen ~10 min) • Mechanical Design and Installation (Larry Bartoszek ~30 min) • Electrical Design and Controls (Al Legan ~20 min) • Cost and Schedule (Larry Bartoszek ~20 min) • Note that we have allowed an hour for interactions with the committee so please feel free to ask questions.
What Are We Trying to Achieve? • The Booster is being asked to accelerate protons at much higher rep-rates and with much higher intensities than has ever been contemplated in the past. • In order to control activation of Booster components so as to .. • avoid radiation damage to sensitive components (e.g. cables and connectors) • avoid excessive exposures to personnel, particularly in high maintenance areas (RF stations) • we need to intercept those protons that are doomed to be lost and ensure ... • they are lost at as low an energy as possible • they are lost in a location that is well shielded
Specifications • The collimators should reduce losses at other locations around the ring without significantly impacting the overall efficiency. • They should be able to handle losses from .. • 20% of the beam at 400 MeV • plus 1% of the beam at 8 GeV • assuming 5E12 p/cycle @ 10 Hz • The shielding should such that under these conditions ... • The above ground radiation does not trip the Chipmunk detector • Activation of water in the sumps is within the allowed limits for surface discharge • Activation of the outside surfaces that are accessible to personnel is less than 100 mrem/hr
Mechanical Specifications • The mechanical/electrical design should be such that .. • the apertures do no occlude any beam when in the out position • they can be remotely translated by 1.5 inches both horizontally and vertically • they can be remotely positioned to an accuracy of ~ 1mm • their orientation can be remotely corrected for pitch and yaw misalignments of up to +/- 10 mr. • The time required to move them from fully in to fully out should be no longer than a few minutes. • It should be possible to reliably disable the motion controls • All sensitive components should be serviceable without major disruptions to the program • It should be possible to completely remove them from the tunnel even after many months of beam.
The Solution – Primary Collimators Two primary scattering foils Mounted on horizontal and vertical drives Installed in sector 5 mini-straights Foils scatter protons on the edges of the beam envelope The scattered beam in intercepted by the downstream secondary collimators
The Scheme Appears to Work. • An early study compared losses around the ring with the vertical primary collimator in and out of the beam and constant efficiency. • Losses decreased everywhere except near the secondary collimator locations BLM’s with collimator out – BLM’s with collimator in
Secondary Collimators – Old Design • Original design consisted of “L” shaped copper scrapers brazed to a copper beam pipe. • Stands and motors were designed to allow lots of room to stack steel shielding For testing purposes they were initially installed without shielding. A major design flaw was realized in January when we were ready to add the shielding. To access the collimator itself in the event of a catastrophic failure would require removing the shielding and exposing a VERY hot object. The design was abandoned. The system had been reviewed in October 2002.
The Solution – New Secondary Collimators Three identical collimators Two in Long 6 One in Long 7 Shielding is integrated with the collimator motors, controls, and moving parts are protected from the radiation
Summary • We believe we have a much better design that meets the requirements for serviceability. • The integrated shielding concept has the advantages that • ALL failure prone components are outside the shielding • The shielding is more uniform ( no cracks or gaps ) • It requires less steel because it makes maximal use of the available space • There are no air activation issues since there are no air pockets in regions of high radiation • But ... we do not want to repeat our past mistakes • So ...Please tell us what have we missed!