John Learned at Gatlinburg 4/05 Tracking in KamLAND? Tracking in KamLAND? CAN WE USE OPTICS TO IMAGE TRACKS AND WHAT WOULD IT GET US? John Learned University of Hawaii At KamLAND Collaboration meeting Gatlinburg, Tennessee, 4/05 Byron Dieterle has done optical studies, thought about problem, and been a great help in developing this idea.

John Learned at Gatlinburg 4/05 Basic Idea: a Scintillator “Bubble Chamber” If we can design the optics with enough light collection adequate depth of field and not much rescattering of light Reconstruct tracks and precise vertices.Reconstruct tracks and precise vertices.

John Learned at Gatlinburg 4/05 KamLAND Physics Applications Accelerator neutrinos: superior recognition of electron events and rejection of π o s. PDK: excellent K mode resolution. SN: resolution of direction. Reactors: better e + -n direction resolution. Solar Nu’s: Some directionality. Muons: very accurate track reconstruction, increased rejection of backgrounds. Nuclearites, Q-Balls, etc. : not presently recorded in SK or KL (?)… opportunity.

John Learned at Gatlinburg 4/05 Sensitivity & Implications Aperture: assume 8 x 17”PMTs (~1.2m pupil) Similar QE, efficiency Assume 8 wide field cameras ~2.4 PE/cm track in each camera 40 MeV track yields ~200 pixels 1 MeV yields ~10 pixels Aim for resolution ~4 mm Implies camera with ~4M pixels => commerically available CCDs

John Learned at Gatlinburg 4/05 Starting point: ASHRA Imaging Particle Detector Pixel Cost Reduction by O(10 4 ) Key Technology 9M-pix. CMOS Sensor Covering 50deg-FoV PMT-array Camera CMOS Sensor Chip 4,500x3,000 (14M) pix. Commercial CMOS Camera Ideas and leader: Makoto Sasaki, ICRR

John Learned at Gatlinburg 4/05 Design of Ashra Optics F/0.74 Details can be found in M.Sasaki et al, NIM A492 (2002) 49 Schmidt-type optics Spherical segment mirror Spherical focal surface 3-element corrector lens Advantage: a large degree of freedom for optimization of lens surface shape to cancel 1.spherical aberration 2.chromatic aberration. pupil : 1m Modified Baker-Nunn

John Learned at Gatlinburg 4/05 Performance of Ashra Optics wavelength incident angle 4 largest peaks in air-fluorescence spectra incident angle Spot diagram after optimization

John Learned at Gatlinburg 4/05 performance of Ashra Optics Spot size = °(1 arcmin) using ZEMAX by A.Okumura incident angle from weighted sum of several wavelength Ashra Optics has capability to achieve 1 arcmin resolution within the whole FOV of ± 25°

John Learned at Gatlinburg 4/05 3mφmirror 1 deg/Pix 3mφmirror 3mφmirror 3mφmirror 1 arcmin/Pix 3mφmirror 1 deg/Pix 3mφmirror 3mφmirror 3mφmirror 1 arcmin/Pix What this does for ASHRA EAS air fluorescence angular resolution 1arcmin ASHRA Angular Resolution eV 0.3 arcmin at E ~ eV

John Learned at Gatlinburg 4/05 R&D 状況ー 2/3 モデル望遠鏡 I.I. 補正レンズ ミラー 2/3 scale prototype

John Learned at Gatlinburg 4/05 Image Intensifier Pipeline 46 Lp/mm => σ~7μm ~ CCD pix. size magnification factor = 1 magnification factor = Lp/mm input surface de-magnification factor ～ 10 de-magnification factor ～ 10 photocathode photon gate pulse >5ns phosphor screen Proximity focused I.I. Focal sphere => => CMOS Sensor Minimum modification of focal surface commercialASHRA I.I. Lens I.I. Incident photons

John Learned at Gatlinburg 4/05 Large Diameter Image Intensifier Existing 16” (400mm)φphotocathode  photocathode resolution 3.4 line pair/mm (largest and finest resolution in world)  24“ under development (but maybe 20” limit)

John Learned at Gatlinburg 4/05 Prototype Image Pipeline Not needed for KL application

John Learned at Gatlinburg 4/05 Add Cameras to KamLAND? Would require draining the detector: stopper? Present idea based on ASHRA size camera. Maybe smaller camera which replaces 1 PMT and requires no cutting steel, but then need More cameras.

John Learned at Gatlinburg 4/05 Beam4 Calculations 9 surfaces sas16.opt Diameter dia index Zvx Curv A4 A6 A8 shape Mir/Lens : : : : : : : : : : : : : -.22 : -0.0 : 0. : 0. : 0. : 1. : lens : L : : : : : : : 0. : 1. : lens : L : : : -.05 : : : : : 1. : lens : L : : : 0.0 : -0.0 : 0. : 0. : 0. : : iris : L : : :.05 : : : : : 1. : lens : L : : :.195 : : : : 0. : 1. : lens : L : : :.22 : -0.0 : 0. : 0. : 0. : 1. : lens : L : : :1.50 :-.667 : : : : 1. : mirror : M : : :0.694 : : : : : 1. : other : D Simple setup, easy to get started Start with Sasaki design Can do simple optimization Example of card file below: Calculations by Byron Dieterle

John Learned at Gatlinburg 4/05 Byron has done some Beam4 Sims for KL-like Geometry Conclude: resolutions of order of mm are achieved at IIT.

John Learned at Gatlinburg 4/05 Image of a Track Use tomographic methods to reconstruct out of focus image.

John Learned at Gatlinburg 4/05 Conclusion Idea to add imaging to KamLAND needs study…. optics, design practicality, sensitivity, reconstruction. How about small camera in place of a neck 6” PMT? Could do muon tracks, nuclearites? Biggest question: does it buy us something really important? Should we pursue it? Anyone interested?