From Physics model to Engineering model

Vane type RFQ designs MOD_JPARC SNS JPARC Japan Proton Accelerator Research Complex Spallation Neutron Source TRASCO THIN Trasmutazione Scorie

SNS RFQ parameters SNS: Spallation Neutron Source Where: Lawrence Berkeley National Lab (LBNL) RFQ type: 4 vane Beam type: H- Beam Acceleration: 65 keV to 2.5 MeV Operating frequency: 402.5 MHz Beam current: 52 mA Length: 4 x 3.7 metre sections Cooling channels: 4 (1 each per vane) 12 (3 each per cavity wall section) Duty Factor: 6% Frequency sensitivity (thermal): 33 kHz per 10C change in vane water temperature Frequency sensitivity (dimensional): 1 MHz per 25 micron change in vane tip-to-tip spacing.

Solid copper versus plated alternative Material Choice Or Solid copper versus plated alternative Solid - Other vane type RFQ designs are predominantly fabricated from solid copper Copper machines poorly + low stiffness + heavy Copper is expensive Plated - Plating to cover joint interface Plating makes scratches worse Requires re-machining – e.g. on a diameter 50 by 450 bar, 50 microns in the centre would require 75 – 100 microns at the ends – a dog bone. Electroless nickel plate first. Expansion coefficients Conclusion – Manufacture from solid copper

CAD model is parameter driven

One quarter vane – machined component

One quarter vane – machined component

RFQ components

Complete model

Brazing details Braze Material: Nickel based eutectic Form of braze material: Paste + wire + shim Number of braze operations: 1 Braze joint design: Radius groove + capillary (zero thickness) Number of joins: 2 x End flanges 12 x KF40 flanges 24 x Cooling channel plugs Braze company: Tecvac Turn-around-time: One week Approx cost: < £1000

Tecvac Ion Implantation is cold surface treatment. The surface is bombarded with high-energy Nitrogen ions under vacuum. In many materials this increases the surface hardness, and because of the compressive stresses induced in the surface, fatigue resistance is also improved. Applications include:- surgical implants and instruments, paper knives, plastic moulding dies and screws. Wall work Heat Treatment have always followed a policy of investing in the most up to date equipment, in this case a 10 bar nitrogen pressure quench furnace with convection heating and the capability to carry out isothermal quenching. This enables steels such as H13 to be treated To maximum hardness with minimal distortion. The majority of coatings supplied by the Wallwork Group are applied by Physical Vapour Deposition (PVD) using the electron beam evaporation method. This gives the smoothest and most defect free coatings of all the PVD methods. It is particularly suitable for high quality components where finish is of great importance. Applications include:- gas turbine blades, motorsport components, medical implants and high quality tooling.

C101 Copper

Finite Element Analysis Tmax = 50.3°C Dmax = 0.051mm Thermal calculations Gun drilling Deflection due to self weight

RFQ Rod Manufacture