09:40 – 10:00 (JST) Wed 5 Mar 2008 MONALISA : JAI Oxford MDI ATF2 TILC08 Sendai Japan 1 / 26 MONALISA Laser based alignment and stability monitoring

09:40 – 10:00 (JST) Wed 5 Mar 2008 MONALISA : JAI Oxford MDI ATF2 TILC08 Sendai Japan 2 / 26 The Oxford MONALISA Group David Urner Paul Coe Matthew Warden Armin Reichold Geoffrey Rayner MPhys alumnus Interferometer experience at Oxford –built up since mid 1990s Interferometer based alignment is "coming of age" –Key results imminent from 3 interferometer groups –IWAA 08 presentations

09:40 – 10:00 (JST) Wed 5 Mar 2008 MONALISA : JAI Oxford MDI ATF2 TILC08 Sendai Japan 3 / 26 Interferometers: Best of old & new In 2008 we have –laser sources –fibre amplifiers –fibre coupling Enabling –radiation tolerance –cost effective –scaleable –rapid read out High precision in fundamental physics since 1887

09:40 – 10:00 (JST) Wed 5 Mar 2008 MONALISA : JAI Oxford MDI ATF2 TILC08 Sendai Japan 4 / 26 Why 2008 is so exciting for us MONALISA enjoying fruitful collaboration in Oxford: –LiCAS Prototype rapid survey system (tests in DESY) –ATLAS: SCT optical alignment being completed at CERN The whole is greater than the sum of the parts

09:40 – 10:00 (JST) Wed 5 Mar 2008 MONALISA : JAI Oxford MDI ATF2 TILC08 Sendai Japan 5 / 26 Beam based feedback Is essential for ILC, CLIC Requires an operational beam –prerequisite initial alignment –components move after survey Working alignment needs to be maintained / restored –between trains 200 ms is long enough for several 100 nm movement –after push-pull events: IR hall floor will move after rolling two heavy detectors –after shutdown periods

09:40 – 10:00 (JST) Wed 5 Mar 2008 MONALISA : JAI Oxford MDI ATF2 TILC08 Sendai Japan 6 / 26 Component Alignment Challenge relative mechanical DoF between many neighbouring components –choose important rotations / displacements in-situ –hostile radiation environment –cramped spaces ILC, CLIC require large dynamic range (sub) nm precision over range of metres micron precision over many 10s of metres

09:40 – 10:00 (JST) Wed 5 Mar 2008 MONALISA : JAI Oxford MDI ATF2 TILC08 Sendai Japan 7 / 26 MONALISA: Benefits 1 Monitoring fiducial locations on key components after interruption of beam – independently follows changes in alignment during commissioning / start up –improves understanding of machine behaviour before accelerator operation –speeds up initial convergence of machine

09:40 – 10:00 (JST) Wed 5 Mar 2008 MONALISA : JAI Oxford MDI ATF2 TILC08 Sendai Japan 8 / 26 MONALISA: Benefits 2 Return detector / QDzero position after push-pull expect to get micron repeatability –for return of magnet positions get machine within beam based capture range –improves switchover time more reliable accelerator operation –lower chance of damage –luminosity can only win

09:40 – 10:00 (JST) Wed 5 Mar 2008 MONALISA : JAI Oxford MDI ATF2 TILC08 Sendai Japan 9 / 26 MONALISA : Requirements The ideal for any survey/monitor system –measure distances along clear lines of sight –use evacuated narrow tubes MDI issues for detector LoI –issues broadly as discussed here at SENDAI in Tuesday MDI session –e.g. push pull vacuum connections

09:40 – 10:00 (JST) Wed 5 Mar 2008 MONALISA : JAI Oxford MDI ATF2 TILC08 Sendai Japan 10 / 26 Personal comments to add to Sendai meeting MDI discussion QD zero in tunnel scenario very exciting –MONALISA (as other systems) much simpler / cheaper much easier to achieve target performance –Personal plea to consider it favourably –IMHO: Achievable luminosity probably greater with simpler ILC

09:40 – 10:00 (JST) Wed 5 Mar 2008 MONALISA : JAI Oxford MDI ATF2 TILC08 Sendai Japan 11 / 26 MONALISA illustration Returning to buried QDzero scenario following sequence shows an ILC study –simulated example geometry –compact straightness monitor (CSM) concept arises from necessity

09:40 – 10:00 (JST) Wed 5 Mar 2008 MONALISA : JAI Oxford MDI ATF2 TILC08 Sendai Japan 12 / 26 Geometry Measure movement of QD0s with respect to some points radially outwards through detector field yoke Then must measure the relative motion of these end points Exact geometry to be determined in synch with detector design Final Vertically Focussing Quadrupole Solenoid return yoke Distance Meter Straightness Monitor Detail for single QDzero

09:40 – 10:00 (JST) Wed 5 Mar 2008 MONALISA : JAI Oxford MDI ATF2 TILC08 Sendai Japan 13 / 26 Geometry Measure movement of QD0s with respect to some points radially outwards through detector field yoke Then must measure the relative motion of these end points Exact geometry to be determined in synch with detector design Final Vertically Focussing Quadrupole Solenoid return yoke Straightness monitor concept

09:40 – 10:00 (JST) Wed 5 Mar 2008 MONALISA : JAI Oxford MDI ATF2 TILC08 Sendai Japan 14 / 26 Geometry Extension into tunnels possible. Allows monitoring of other magnets positions with respect to QD0 Final Vertically Focussing Quadrupole Solenoid return yoke

09:40 – 10:00 (JST) Wed 5 Mar 2008 MONALISA : JAI Oxford MDI ATF2 TILC08 Sendai Japan 15 / 26 Measurement lines We measure distances along measurement lines using two techniques: Absolute distance interferometry Displacement interferometry Each line is the same, and is capable of performing both types of measurement. Absolute distance Displacement

09:40 – 10:00 (JST) Wed 5 Mar 2008 MONALISA : JAI Oxford MDI ATF2 TILC08 Sendai Japan 16 / 26 FSI: Frequency scanning Interferometry

09:40 – 10:00 (JST) Wed 5 Mar 2008 MONALISA : JAI Oxford MDI ATF2 TILC08 Sendai Japan 17 / 26 Interferometer operation Intensity

09:40 – 10:00 (JST) Wed 5 Mar 2008 MONALISA : JAI Oxford MDI ATF2 TILC08 Sendai Japan 18 / 26 Interferometer operation Phase = 2π (Optical Path Distance) / Wavelength Φ = 2π D / λ = 2π D (ν / c) D = (c/ 2π) (ΔΦ/Δnu) R = (c/ 2π) (Δθ/Δnu) D = R (ΔΦ/Δθ) ΔD = (c/2π ν) ΔΦ Fixed Frequency Interferometry Frequency Scanning Interferometry

09:40 – 10:00 (JST) Wed 5 Mar 2008 MONALISA : JAI Oxford MDI ATF2 TILC08 Sendai Japan 19 / 26 FSI: recent results in air MHz raw signal  =750nm  =70nm Add box to reduce air turbulence Distance RMS < 1  m

09:40 – 10:00 (JST) Wed 5 Mar 2008 MONALISA : JAI Oxford MDI ATF2 TILC08 Sendai Japan 20 / 26 FFI: recent results in air Following displacements 5 nm RMS Four fibres' raw signal Displacement Static resolution estimate MHz raw signal

09:40 – 10:00 (JST) Wed 5 Mar 2008 MONALISA : JAI Oxford MDI ATF2 TILC08 Sendai Japan 21 / 26 Up coming work at Oxford Have vacuum vessel ready for testing interferometers down to below 1 mbar Frequency stabilised ultra-narrow linewidth laser will improve reliability of FFI displacement measurements

09:40 – 10:00 (JST) Wed 5 Mar 2008 MONALISA : JAI Oxford MDI ATF2 TILC08 Sendai Japan 22 / 26 Vacuum Vessel (0.1-1mbar) Equipped with 4 x 8 way fibre AFTER BEFORE 800mm LID NOT SHOWN HERE!

09:40 – 10:00 (JST) Wed 5 Mar 2008 MONALISA : JAI Oxford MDI ATF2 TILC08 Sendai Japan 23 / 26 Rb-87 frequency reference (FFI) Target ~3 khz linewidth Need 19 kHz for 10m Almost all equipment has been ordered or purchased : setting up from March on

09:40 – 10:00 (JST) Wed 5 Mar 2008 MONALISA : JAI Oxford MDI ATF2 TILC08 Sendai Japan 24 / 26 ATF2 extraction line: 08 Feb 2008 QD0 QD1

09:40 – 10:00 (JST) Wed 5 Mar 2008 MONALISA : JAI Oxford MDI ATF2 TILC08 Sendai Japan 25 / 26 ATF2 beam direction QD0 Shintake table ATF2: Monitor relative vertical motion

09:40 – 10:00 (JST) Wed 5 Mar 2008 MONALISA : JAI Oxford MDI ATF2 TILC08 Sendai Japan 26 / 26 Summary MONALISA will be a boon to ILC –QDzero nanometre vertical alignment –Repositioning after push-pull to microns Needs to be included in MDI engineering and detector layout –push to get MONALISA concepts into detector –greatly encouraged by creative thinking at TILC08 Performance demonstrations on going –Oxford: Vacuum and frequency reference systems –ATF2: Final focus monitoring system to be installed