How much do the vanes grow longitudinally under normal heat loads?

How much do the vanes grow longitudinally under normal heat loads?

• How much do the vanes grow longitudinally under normal heat loads?

• What is the variance in the growth?

• i.e. what are the tolerances?

• What stresses do the clamping faces see?

• What happens if no gap is left to allow growth and the vanes of each section are just butted up to each other?

Section 2 or 3 of RFQ (no cutback etc)

• Section 2 or 3 of RFQ (no cutback etc)

• Fully featured major and minor vanes

• High mesh accuracy at vane ends

• Cut by three symmetry planes

• Expansion prevented across symmetry planes

• 800kW peak input RF at 10% duty factor

• Large over-estimate of heat for safety factor

Vary cooling efficiency

• Vary cooling efficiency

• Baseline, expected cooling performance
• Pessimistic cooling performance
• Worst case cooling, far below expectations

• Vary movement constraints

• Fixed clamping face, free vane ends (baseline)
• Both clamping face and vane ends fixed
• Entire end free to grow longitudinally
• Baseline longitudinal constraints, but vanes unable to grow transversely outward

Easy to tweak flow rates to get a uniform temperature

• Easy to tweak flow rates to get a uniform temperature

• The cooling system is quite effective at removing heat evenly along the length of the RFQ

• This results in little longitudinal growth

• Typical longitudinal growth of a vane end is 40µm

• Maximum growth of one section will not exceed 250µm

• ∴ a 0.5mm gap between vane ends of two sections will be more than sufficient even if we need much more RF power than anticipated and the cooling system fails

• Require longitudinal and transverse gaps for growth

• Cooled flange brings small benefits but is not essential

• Transverse growth still <20µm as previously found