1 / 21

Minos Detector Experience in brief

Minos Detector Experience in brief. The Minos Context Detector Essentials & Elements Assembly, installation, maintenance Event reconstruction, resolutions, profiles Finer grained calorimeter. Geoff Pearce, RAL NF detector technology discussions I.C. May 7, 2005. Minos - context.

everly
Download Presentation

Minos Detector Experience in brief

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Minos Detector Experiencein brief • The Minos Context • Detector Essentials & Elements • Assembly, installation, maintenance • Event reconstruction, resolutions, profiles • Finer grained calorimeter Geoff Pearce, RAL NF detector technology discussions I.C. May 7, 2005

  2. Minos - context • High intensity νμ beam from Fermilab to Soudan (Mn) • Two detectors, Near (1kT) and Far (5.4kT) • Primary measurement : Compare ν energy spectrum in the Far Detector to the un-oscillated expectation from the Beam and Near Detector • Observe oscillation minimum • Confirm oscillatory behaviour in νμ sector • Measure Δm232 to ~10% • Look for νμ→ νe oscillations, measure θ13? Baseline : 730km 1kton near detector 5.4kton far detector

  3. _ Both νµ and νµ beams Minos – Energy Regime Nominal Beam Configurations 120GeV M.I. protons, graphite target 2.5 1013 / 8.67 µs pulse, 1.9s rep. rate (.25MW) Beam energy can be tuned by adjusting position of 2nd horn relative to target Energy regime ~ 1 – 25 GeV Δm2 expectation dropped considerably since conception/design LE beam best match for Δm2 ~ 2-3 10-3 eV2at the Minos baseline Lower energy than NF, but not too disimilar

  4. Veto Shield The completed Minos Far Detector Coil MINOS Far DetectorEssential features • 5.4 kton magnetised tracking calorimeter, B ~1.5T • 484 steel/scintillator planes built in 2 supermodules • 2.54cm thick steel, 192 4x1cm scint. strips per plane • orthogonal orientation on alternate planes – U,V • optical fibre readout • Veto shield covers top/sides for atmospheric v • Multi-pixel (M16) PMTs read out with VA electronics • 8-fold optical multiplexing • chips individually digitised, sparsified & read out when dynode above a threshold • excellent time resolution – 1.56ns timestamps • Continuous untriggered readout of whole detector • Interspersed light injection (LI) for calibration • Software triggering in DAQ PCs (independent of ND) • highly flexible : plane, energy, LI triggers in use • spill times sent from FNAL to FD trigger farm • GPS time-stamping to synch FD data to ND/Beam

  5. U U U U V V V V steel scintillator orthogonal orientations of strips Detector Elements Scintillator strips in light-tight modules, 8/plane 192 scintillator strips on each plane Steel scintillator sandwich 25.4mm steel, 1cm scintillator Alternate planes have orthogonal strip orientations (U,V) • Fibres carry light to MAPMTs • M16 (FD) M64 (ND) • Optical multiplexing in FD • 8 fibres per pixel 4.1cm x 1cm extruded polystyrene strips TiO2 reflective coating Groove for 1.2mm WLS fiber to collect light M16

  6. Module Assembly & Testing Design lends itself well to parallel construction Matches many University workshop capabilities Multiple factories for scintillator planes used by Minos Division of labour – construction speed Cost ~ $600 / module These can be important considerations Gluing WLS fibers Placing Scintillator strips in light case

  7. Detector assembly and Mounting • FD most challenging • Remote (Soudan, Mn) • narrow mine shaft • taken down in pieces and assembled underground • ND planes assembled above ground • Both detectors installed to schedule Installation / maintenance at remote location highly successful

  8. MINOS Near DetectorEssential features Same basic design as Far Detector Minos Near Detector as installation neared completion • 1 kton (total mass) magnetised tracking calorimeter • Partially instrumented • 282 steel planes, 153 scintillator planes • reduced sampling in rear planes (121-281) “spectrometer section” used for muon tracking • High instantaneousν rate, ~ 20ev/spill in LE beam • No multiplexing except in spectrometer region (4x) • Fast “QIE” electronics • continuous digitisation on all channels during spill • (19ns time-slicing). Mode enabled by spill signal. • dynode triggered digitisation out of spill (cosmics) • GPS time-stamping / Software triggering in DAQ • all in spill hits written out by DAQ • standard cosmics triggers out of spill

  9. m n ‘u’ - view m ghost hits due to multiplexing n m ‘v’ - view m strip # plane # Event Reconstruction Strip readout provides two 2D views (U,V) – combine to get 3D hits Resolution ~ strip width (angular resoln. on moon shadow <0.5deg) Multiplexing at FD complicates reconstruction, but soluble. MC event – zoomed in

  10. (Real) Far Detector Beam Event νµ

  11. Near Detector Eventsspecial needs One spill in Medium Energy Beam Intensity = 2.5 1013 pps Multiple events in detector Events resolved using timing ND readout has 19ns bucket resolution Near Detector must be able to cope with high rate

  12. UZ B VZ time PEs Magnetic Field • 1.5T magnetic field in steel generated by coil • Momentum measurement • Charge separation Δpµ/pµ = 10% (curvature) Δpµ/pµ = 6% (range – if available) Good knowledge of field vital Far Detector cosmic muon (courtesy MT) Stopping muon Prange = 3.86 GeV/c Pcurvature = 4.03 GeV/c

  13. Calibration DetectorThe 3rd major Minos detector • Vital to understand energy response to reconstruct Eν • Eν = pµ + Ehad • Minos design ports very well to test beam studies • Can study detector issues vital to physics • Minos built a 1m x 1m x 3.7m “mini-Minos and ran in CERN test beams to • study response to π, µ, e, p • test MC simulation • look at near / far detector differences • energy scale calibration

  14. CalDet : sample events at 2 GeV TOF/Cerenkov system at CalDet provides pure samples Colour scale = MIPs Energy distribution profile used to identify pid in Minos M. Kordosky

  15. MC expectation Minos Calibration DetectorResponse to π, p, e Preliminary Energy Resolution CalDet analysis nearing completion. Publications in preparation

  16. UZ NC Event nm CC Event n • often • diffuse VZ • m track • +hadronic • activity NC Event ne CC Event • can mimic • nm , ne • compact • shower • typical EM • shower • profile MINOS Event Profiles MCARLO νe / NC challenging but do-able at low energies.

  17. Built for NDK, ~ 1Gev 1.6mm thin steel (Minos has 25.4mm steel)

  18. Soudan2 events High resolution Bubble chamber quality 410 MeV electron shower Gaps from γ propogation Steel thickness can be tuned to needs -- and wallet

  19. Summary and Conclusions • Modular, simple, low risk, safe, not expensive • Magnet field can be applied over whole steel volume • Momentum measurement • charge ID • You get iron. • Sampling frequency, steel thickness can be chosen to match physics requirements • Active components would be chosen to optimise cost/performance • Scintillator (eg liquid, like Nova) • Photodetectors (eg MA256, HPD, etc) • Electronics, DAQ would clearly be chosen from technology of the day • Near detector can be same technology • Minos style detector is an option worth consideration

  20. Soudan events High energy event fast exiting muon two interacting pions

More Related