Download NLC Beam Delivery vacuum specification for the purpose of

NLC Beam Delivery, Systems Engineering_Rev_2, 03/17/98, Leif Eriksson
NLC BD vacuum specfications for the purpose of cost estimation and
WBS
GENERAL
The NLC Beam Delivery vacuum system is an Ultra High Vacuum system. All components in direct
contact with the NLC Beam Delivery vacuum system must comply with “Technical Specifications for
Vacuum Systems”, SLAC-TN-86-6.
BASE PRESSURE
The highest pressure in the NLC Beam Delivery System must not exceed 5E-8 Torr.
PUMPS
The NLC Beam Delivery vacuum system is ion pumped, the pump size is 30 l/s.
The ion pumps are of VARIAN type with a removable, gold plated high voltage feed through.
The pumps should have remote high voltage power supplies accessible during operation.
The high voltage ion pump power supplies should display error codes into a central control system.
The spacing of the ion pumps is one ion pump every 10 –15m depending on beam line apperature.
The ion pumps are located immediately adjacent and perpendicular to the beam line
The ion pumps are connected to the beam line through a flange connection.
Each ion pump has its own mechanical support.
BEAM LINE
The preferred material for the beam line is copper due to its low out gassing rate, its low electrical
resistance and its good thermal properties.
Flange connections are made by ConFlat type vacuum flanges.
All vacuum seals in areas in direct contact with the beam must be all-metal.
Flange connections will be used in component dense areas.
Where the component density is low the beam line sections will be welded/brazed together in situ.
GAUGES
One gauge assembly measuring total pressure from atmospheric pressure to 2E-10 Torr, every 250m. The
gauges must be radiation hardened.
All functions of the gauge(s) should be able to operate remotely.
Every beam line section must have a gauge combination, as described above, on both sides of a beam line
isolation valve.
RGA
Every 250m section should contain two Residual Gas Analyzers of radiation hardened type.
All functions of the RGA should be able to operate remotely.
VALVES
The beam line isolation valves are all-metal valves of VAT type, radiation hardened.
The bore is no larger than 1.50”.
The actuator should be mounted on an extender.
The valves must have mechanical indicators displaying OPEN and CLOSED.
The valve must have micro switches indication OPEN and CLOSED.
The valves must be operated by a remote solenoid package, J-box, of SLAC type.
The valves should have local controls every 500m.
The valves are located 250 m apart.
All metal right angle valves, 2 ¾” CFF should be provided every 50m.
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NLC Beam Delivery, Systems Engineering_Rev_2, 03/17/98, Leif Eriksson
TUNNEL ACCESS
Access to the tunnel will be provided every 500m.
A power supply/control room will be provided on the ground level adjacent to the tunnel access every
500m. No cable length from a beam line vacuum device to the power supply/ controls vault should have to
be longer than 300m.
VACUUM CONTROL ROOM
The NLC Beam Delivery System should have a centrally located vacuum control room for e - and e+.
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