M. JimenezAT/VAC

Room Temperature (LSS) Vacuum Systems

M. Jimenez

M. JimenezAT/VAC

Main Topics

• Introduction to the RT LSS Vacuum Systems• Installation Sequence

– Mechanical installation– Check-out of the Instrumentation and Control System– Bake out and NEG activation

• Vacuum Control and Interlock Systems Commissioning• Failure scenarios and their impacts• Overlap between RT vacuum system installation & HC

M. JimenezAT/VAC

Introduction to the RT LSS Vacuum SystemsLSS RT Elementary Sector

Ref: LHCLJV_L0011

M. JimenezAT/VAC

Introduction to the RT LSS Vacuum SystemsKnow-how

• Well known procedures validated during the installation and operation of previous accelerators like ISR and LEP

• The use of NEG coated chambers requires additional precautions:– Limit the exposure of the coatings to ambient atmosphere,– Avoid any leak prior or during the activation cycle (performance

dramatically reduced),– Special bake out and NEG activation cycles for tanks with BN or

C-C (TDI, TCDx and collimators).

Laboratory and LEIR experience confirmed the procedures

M. JimenezAT/VAC

Installation SequenceMechanical Installation• Installation of the standalone magnet cryostats

– Connection of the standalone beam vacuum to the pumping modules– Pumping & leak detection (4-6 weeks required to go down to 10-7 mbar)– Bake out of RT parts of the standalone cold sector prior to cool down in the background of the interconnections & assembly of inner triplets

• Installation of the RT vacuum sectors– Marking & installation of the supports, installation of machine elements– Installation of vacuum chambers, transitions, bellows, pumping and

instrumentation modules– Survey (AT/VAC), pumping and leak detection

• Bake out installation and check-out– Installation of the heaters, cabling and connection to the regulation box– Check-out of the cabling by launching a short cycle– “Cleaning” of the area to allow night transportations

• Vacuum Instrumentation and Control System– Installation of ion pump power supplies, gauges and sector valves

controllers in the racks– Cable connection on the equipments in the tunnel

M. JimenezAT/VAC

Installation SequenceCheck-out of the Instrumentation & Control System

• Prior to these activities, the RT sector shall be under vacuum, leak tight and with the installation of the instrumentation and Control system completed

• Check list:– Control cable at the level of the sector valve disconnected (avoid

manipulations)– Gauges and ion pumps connected and controlled electrical

test, shall not be powered ON to avoid contaminations (230 V disconnected)

– Connection to the controllers and verification of the communication interface with the PLC master

– Verification of the vacuum interlocks to the bake out regulation Controller

M. JimenezAT/VAC

Installation SequenceBake out and NEG activation

• Prior to these activities, the RT sector shall be under vacuum, leak tight and with the installation of the instrumentation and Control system completed and checked

• Bake out and NEG activation sequence:– Checking the entire system

½ d

– Programming the bake out and NEG activation cycles

– Bake out of the non NEG coated components 1.5 d

– NEG activation 1.5 d

– Removal of bake out and pumping equipment1 d

Transport restrictions during the NEG activation when T>180 °C Will be planed during the day

M. JimenezAT/VAC

Vacuum Control & Interlock Systems Commissioning

• Prior to these activities, the RT sector shall be under vacuum, leak tight, the installation of the instrumentation and Control system completed and the vacuum systems (standalone cold and RT with NEG activation) according to the specifications

• Sequence of commissioning– Reconnection of the sector valves– Checking the sector valves

• Sector @ RT / Sector valve / Sector @ RT Upstream and downstream RT sectors baked and with NEG activated• Sector @ RT / Sector valve / Cold Sector (Standalone) RT sectors baked and with NEG activated and Cold sector (standalone)

@ 4.5 K (1.9 K pour les triplets)– Checking the interface between the vacuum system and the BIC No activities in parallel to limit consequences when manipulating the

sector valves• If the required conditions are not available, the commissioning will

be postponed and will take place during the Hardware Commissioning, after achieving the specified conditions.

M. JimenezAT/VAC

Failure scenarios and their impacts Overlap between RT vacuum system install. & HC

• Failure scenarios– Leak on the cold beam vacuum

Shall be repaired prior to the cool down

– Replacement of a failing equipment– Leak on a RT beam vacuum after the bake out or NEG

activation– Vacuum specifications not achieved

Bake out and NEG activation shall be repeated

• Overlaps– Delays in the installation of machine elements– Delays in the verification of the interlocks

• Sector valves interlocks

• Interlocks with the BIC