neutrino factory design overview and ids-nf status michael s. zisman* c enter for b eam p hysics

February 28, 2011 NF Report - Zisman 1

Neutrino Factory Design Overviewand IDS-NF Status

Michael S. Zisman*Center for Beam Physics

Accelerator & Fusion Research DivisionLawrence Berkeley National Laboratory

(*with thanks to: S. Berg, K. Long, J. Pasternak, J. Pozimski, G. Prior, and C. Rogers)

MAP Meeting–JlabFebruary 28, 2011


Outline

• Introduction• Current baseline• IDR designs• IDR status• Progress since ISS• RDR goals• RDR tasks• RDR time scale• MAP contributions• RDR planning• Summary


Introduction

• Neutrino Factory design effort has been carried out internationally for ~5 years– International Scoping Study (“ISS”)– follow-on organization is International Design

Study for a Neutrino Factory (“IDS-NF”)• European NF design effort managed and funded as

part of EUROnu design study– EUROnu looking at 3 possible future neutrino facilities,

along with corresponding detector options (WP5) Superbeam (WP2), NF (WP3) and Beta Beam (WP4) physics performance comparison of all three (WP6)

• EUROnu WP3 is fully integrated with IDS-NF

• Summary of main features follows


Current Baseline (1)

• Baseline has evolved since completion of ISS– mainly front-end optimization– primary “deliverables” unchanged

• System descriptions (to follow) from IDR– http://www.hep.ph.ic.ac.uk/~longkr/tmp/IDS-

NF_IDR/IDS-NF_IDR-D14.pdf• 129 authors (by my count)


Current Baseline (2)

• Schematic of IDR baseline shown here– brief descriptions of individual systems follow


IDR Proton Driver

• Proton driver defined only by performance specifications– several different implementations under

study• ISIS upgrade [Thomason]; high-power SPL

[Garoby], Project X [Gollwitzer]


IDR Target

• Target still Hg jet in 20 T solenoid– shielding for magnets found to be inadequate

• too much heat deposited in coils– progress being made toward improved design

• Fe plug (now eliminated)

McDonald; Kirk; Graves


IDR Front End (1)

• Optimization to make shorter channel [Neuffer]– lattice parameters documented


IDR Front End (2)

• Drift length 111 80 m• Transport field 1.75 T 1.5 T• Buncher section 51 m 33 m (VRF = 9

MV)• Rotator 54 m 42 m (VRF = 12 MV)• Cooling section 75 m (VRF = 15 MV)

[Rogers]L = 120 m

L = 80 m

ISS IDS-NF

Issue of RF in a magnetic field remains


Alternative Front Ends

• Because of RF issue, several alternative approaches still being studied as backups– bucked coil lattice [A. Alekou]– magnetically-insulated lattice [D. Stratakis]– HPRF lattice [J. Gallardo, M. Zisman]

Bucked-coil lattice

Magnetically insulated lattice

HPRF cavity lattice


IDR Acceleration System

• Multiple systems adopted– linac, RLAs, FFAG


IDR Linac

• Linac accelerates to 0.9 GeV [Bogacz]– three sections with increasing cell length


IDR RLAs (1)

• Two RLAs [Bogacz]– 0.9-3.6 GeV (0.6 GeV/pass)– 3.6-12.6 GeV (2 GeV/pass)

RLA1

RLA2


IDR RLAs (2)

• Optics developed to transmit both + and - in opposite directions– quad gradients increase linearly from linac

centerRLA1 linac

RLA2 linac

RLA1 ‘droplet’ arc


IDR FFAG (1)

• FFAG (12.6-25 GeV) [Berg]– linear non-scaling design


IDR FFAG (2)

• Ring uses combined-function Nb-Ti magnets– designs for both F and D magnets in progress

• F magnet shown here; not yet optimized

Iron yoke (field

clamp)

H. Witte


IDR FFAG (3)

• Scheme for injection and extraction has been developed [Pasternak, Kelliher]– requires lots of PFNs

• and lots of power

Injection Extraction


IDR Decay Ring (1)

• Unchanged since ISS

Racetrack[Johnstone]

Triangle[Prior, Rees]


IDR Decay Ring (2)

• Present baseline is racetrack design– more flexible

• two independent sources that can be oriented as needed

• can use either ring for both + and - – no ‘wasted’ beam if one ring or one detector unavailable

– but, at a cost• two tunnels needed• four transfer lines to take full advantage of flexibility

– and decent detector timing (~100 ns)

• Triangle remains a viable alternative– two rings side-by-side in single tunnel

• good detector timing mandatory with this geometry


IDR Status

• Original goals– develop complete (initial) NF accelerator

design– produce initial cost estimate

• Where we are– designs for most systems completed and

lattices available• a few systems known to need work

– E deposition in target region unacceptably high

– no cost estimate is available• Leaders of this phase

– Berg, Pozimski


Progress Since ISS (1)

• Initial concepts of FNAL, RAL proton drivers• Detailed E deposition studies in target area• Many front-end improvements

– shorter phase rotation and bunching systems– assessed impact of reduced VRF in baseline

• studied several alternatives as fallback options– particle loss estimates and mitigation strategy

• Studied more complete RLA designs– symmetric gradient profile– chicanes for arc crossings– chromatic corrections in chicanes


Progress Since ISS (2)

• More realistic FFAG design– longer drifts– higher average gradient– inj/extr system design– initial magnet designs

• Decay ring– studied diagnostics

• polarimeter, angular divergence measurement


RDR Goals

• Complete description of all systems• Assessment of feasibility and

performance– tracking (all systems, then end-to-end)

• with imperfections– sufficient engineering to validate designs of

“tricky bits”– cost estimate for entire facility

• requires adequate level of design detail for engineering estimates


RDR Tasks (1)

• Overall– complete matching section designs to permit

end-to-end simulations– complete engineering design of key components

• issues are feasibility and cost– complete cost estimate

• to be compared with EUROnu estimates for SB and BB– evaluate collective effects for all systems

• Target– develop new solenoid and shielding configuration– define infrastructure


RDR Tasks (2)

• Front end– develop method for handling particle losses– finalize cooling configuration

• issue of RF choice

• Acceleration– confirm mechanical layouts

• transfer lines, switchyards, bypasses, chicanes, arcs– finalize FFAG chromaticity correction scheme– track (with errors) through entire system

• linac, RLAs, FFAG– evaluate cost of including FFAG vs. using only

linac and RLAs


RDR Tasks (3)

• Decay ring– decide on chromaticity correction scheme– define injection scheme– evaluate need for beam abort system– define and design ring diagnostics


RDR Time Scale

• Time scale for all of this effort estimated (Berg) at 2 years– lack of engineering particularly critical– physics effort is also “thin” (and lots to do!)


MAP Contributions (1)

• MAP proposed these IDS-NF activities– proton driver (Project X version)– targetry and target stations– pion capture and muon phase rotation– ionization cooling– accelerator systems– site-specific (FNAL) underground engineering

issues for the muon storage rings– overall coordination of effort for the low-

energy NF option– participating in costing


MAP Contributions (2)

• More or less keeping up with physics effort– engineering effort is lacking

• not obvious how to rectify this with projected budgets

• Proposed activities predicated on reaching $15M per year– right now, we’re at $10M (for reasons beyond

our control)• MICE magnet costs have risen dramatically

and must be covered as the highest priority– leaves little “free energy”

• We must revisit IDS-NF promises/schedule


RDR Planning (1)

• Still (more or less) following original roadmap


RDR Planning (2)

• IDR draft is complete and final comments and corrections being incorporated– includes physics case, accelerator

description, and detector descriptions• Physics case still indicates NF is the most

powerful tool for studying neutrino sector– finds continuum between single-baseline

“LENF” and two-baseline IDS-NF configuration• depends on value of sin2 213

– which may well be known prior to making NF decision

• Lower MIND threshold validated– progress made on defining near detector


RDR Planning (3)

• IDR will be reviewed by ECFA panel on May 5-6, 2011 (at Daresbury Lab)– after which IDR will be updated as deemed

appropriate• then published on arXiv and as CERN Yellow Report

• Ongoing discussion on whether to publish IDR in refereed journal– strong views on both sides– decision at next IDS-NF plenary meeting

• October 17-19, 2011 at Virginia Tech– in any case, need to step up “community

outreach”


Summary

• IDR design completed and documented– S. Berg and J. Pozimski editors of accelerator

section– K. Long overall editor

• Lattices for main elements documented– will facilitate subsequent end-to-end tracking

• Review of IDR by ECFA panel scheduled for May 5-6, 2011

• Plans for reaching RDR being developed– K. Long and IDS-NF steering group

• MAP resources for this task are limited

neutrino factory design overview and ids-nf status michael s. zisman* c enter for b eam p hysics

Documents

ffagnf report zisman

countnf report zisman

nf wp3

idr rlas

idr targettarget

idr linaclinac

schematic of idr baseline

idr proton driverproton