UKNF OsC meeting @ RAL – 31 st January 2011 UKNF achievements & plans J. Pozimski

UKNF OsC meeting @ RAL – 31st January 2011

UKNF achievements & plans

J. Pozimski


WP1 - Major achievements

Benchmarking Fluka results with Mars and comparison with HARP data Investigation of particle dynamics in the baseline muon front end lattice and investigation of

the performance of alternative lattices Studies of power deposition in the target and pion capture area due to secondary radiation Studies of solid and liquidized power jet targets for mercury risk mitigation Detailed studies of fringe field effects, benchmarking of Optima against MADX , GPT and

G4beamline Modelling of accelerator components (cavities, solenoids, dipoles, quadrupoles and

sextupoles), calculation of field maps and comparison with study 2a results Multi-particle simulations of the muon linac using field maps, comparison of gained results

from various software packages with good agreement in transversal and longitudinal particle dynamics and particle loss pattern.

Detailed studies of beam injection and extraction into the FFAG, first preliminary studies of kicker and septum design as well as kicker electronics.

First studies of combined function FFAG magnets and particle tracking in fieldmaps Detailed studies of beam loading effects in the muon accelerator Test of data exchange between accelerator sections for the end to end simulations (muon

front end to muon linac) Studies of beam instrumentation in decay rings Protondriver based on ISIS upgrade : Detailed designs and costing up to 3.2 GeV available,

lattice design for final RCS available. Detailing and costing started.

......IDR written ......


Costing

• First costing workshop spring 2010 at CERN• Costing session at IDR plenary meetings 5 & 6• Costing group established (EURO)• Costing tool available at CERN (used for ILC)• Work breakdown structure defined• Several questions concerning different costing methods,

currency and inflation issues have been discussed.

For IDS “mixed” costing approach according to readiness of the hardware design was planned, “component” list for WBS available

=> Contacts with RAL & DL to cost linac as an example for all other subsections. Preparation for costing workshop started.


FETS


FETS Status

• Ion source operates at nearly design specs (2 ms, 50 mA)• LEBT characterization nearly complete (source alignment)• Beam at injection into RFQ ~ 0.3-0.35 pimmmrad (measured)• Pepper pot alignment setup “finished”• Laser issues still persist, (Laser power/Noise/Electronics but first hint)• RFQ beam dynamics simulations before freeze• Only a few principle design decisions for RFQ left (coupling)• Copper quote available - shortly before order• Circulator ordered and will be delivered in Summer• Tuning system tested (60W pulsed)


Next Steps

• RFQ machining should start in April/May - total machining time ~ until December

• High power RF setup to be finished in summer when circulator arrives

• Experimental programme involving cold model foreseen for summer under discussion

• Beat pull measurements of section 1& 4 in October• Conditioning & first high power test on 1& 4 in December• Sections 2&3 in Spring 2012• Beam measurements Summer 2012-December 2012• Not to much involved in MEBT in the moment• Define work after FETS primary goal• => Laser diagnostics / ESS diagnostics ?• => CH structures and spokes ?• => Plasma lenses / NNP / Electron stripper• => Laser stripper


Targets – strength and lifetime

YM of W and Ta published in J. Nuc. Mat

Tensile strength of W and Ta & lifetimes submitted to NIM AMore than sufficient lifetime demonstrated in wires

Remaining issues: - strain rates different between wires and bars & strength depends on it- being studied with models and experts: invited to workshop in IC- manufacture method also different- will need to put bar in a proton beam to be sure- effect of radiation: looks OK, but needs checking


Targets – target change

• Target wheel upstream of solenoids gives 60% of ST2a – worst we can do

• Target chain being studied – can slot into and out of capture solenoid

• Initial study looks promising, but many issues!

• Three tungsten links being built to test bonding

• (Cheap) steel model being built to test the concept

• Early days

beam

~500 Tungsten barsTungsten link

WS2 coating


Heat load in target station


Heat load in target station

• Various solutions being studied

higher proton energy helps

lower target Z may help, but may bring other problems

more shielding helps, but the magnet is more difficult

• More radical solutions also being studied!


High power RF - Achievements

A series of surface treatment methods are tested on copper buttons : • By looking at the table above, it is possible to see how each stage of production reduced the overall

roughness of the surface studied. While EP gives a smooth surface, the new method tested is capable of producing an even finer finish. The continue reductions in overall roughness is shown by the graph.

• Also, it is possible to see how different stages of production may induce foreign particle into the surface. This is clearly shown above as a phosphor layer is created after EP.

Unlike other tracking codes available, a home grown particle tracker in being developed to study the behaviour of electrons at emission sites in a true 3D environment:

• A series of simulations using Comsol multi-physics has revealed how defects can induce local E and B field enhancements.

• A series of simulations have been carried out in static field, where no external magnetic field is applied.


Plans for Future

This program benefits from the fact that is able to study electron behaviour in a 3D environment. However, due to the extend of computational power needed and the shear size of the cavities being modelled, there are limitations on the quality of the work performed in 3D. This can be resolved by:

• creating a hybrid model, where a local 3D defect model is to be fused with a 2D axis symmetric plain cavity. This would allow the tracker to choose which field profile to be used, depending on the position of the electron in the cavity.

• Also, it is important to study the behaviour of electrons taking into account a time varying RF field.

To this date, a batch of 6 buttons have been produced using method E. This would be extended to 3 more batched, where 2 different EP mixes are to be compared to batch of buttons as received from the vender. It is also vital to perform a full XPS measurement on each button to study the chemical composition of each button. The interferometer data coupled with the XPS results would allow a detailed map of how the is altered at each stage of production to be produced. Once all the data is gathered, all 4 batches are to be shipped to Fermilab, for a High gradient RF testing to establish which techniques yields better resilience to RF field.


Summary

The IDR and numerous Publications, invited talks, PhD's, etc. 1 UKNF plenary meetings 2 IDS plenary meetings EUROnu plenary meetings and costing workshops dozens of work package meetings and workshops Significant contribution to Emma comissioning UKNF overall on schedule and budget

Documents

UKNF OsC meeting @ RAL – 31 st January 2011 UKNF achievements & plans J. Pozimski