1. Nuclear emulsion scanning for double strangeness nuclei search Junya Yoshida, Kazuma Nakazawa, Khin Than Tint, Myint Kyaw Soe, Aye Moh Moh Theint, Shinji Kinbara, Akihiro Mishina, Yoko Endo, Hiroki Ito, Hidetaka Kobayashi Physics department, Gifu University, Japan JSPS KAKENHI 23224006 and MEXT 15001001, 24105002 1

2. ｎ ｎ ｐ ｐ ｎ Ξ-Ξ- X-ray ｎ ｐｎ ｐ ｎ ｎ ｐ ｎ ｐ ｐ ｎ ｎ ｎ ｐ ｐ ｎ Λ ｐ π-π- ｎ ｐ ｐ ｎ Λ Λ PHYSICAL REVIEW C 88, 014003 (2013) Vertex C Vertex B Vertex A #1 Double lambda hypernucleus p + Ξ - → Λ + Λ + 28MeV * Important subject to investigate hyperon- hyperon interaction. * Tiny characteristic shape having 3 vertexes at the rest point of  - hyperon in nuclear emulsion. 2

3. Nuclear emulsion plate: photographic tracking device for charged particles after photographic development charged particles track layer structure AgBr crystals suspended in gelatin. nuclear emulsion plate 3 ~450 micron 40 micron emulsion base Read-out: by optical microscope

4. 4 Emulsion pictures

5. 5 Diamond target  K  (p>1.0GeV/c) KK Double Lambda Hypernucleus Emulsion stack Only 9 events are observed in 2000s in the world. Various double lambda hypernuclei must be detected to investigate  interaction. How we obtain more double lambda hypernuclear events? * The experiment ten times larger than the previous experiment. J-PARC E07 -> Ekawa-san’s talk * PID for daughter nucleus -> Kinbara’s talk

6. 6 disassembled emulsion stack A schematic view of “Track following” thin type plate, good angular resolution: Interface between tracker and emulsion stack. thick type plate, large angular acceptance For detection of nuclear events. PoC. of automated tracking system is ongoing

7. 7 Diamond target  K  (p>1.0GeV/c) KK Double Lambda Hypernucleus Emulsion stack * Latent events (~10 times) may be recorded in existing emulsion. Only 9 events are observed in 2000s in the world. Various double lambda hypernuclei must be detected to investigate  interaction. How we obtain more double lambda hypernuclear events? * The experiment ten times larger than the previous experiment. (J-PARC E07) * PID for daughter nucleus -> Kinbara’s talk * New searching method: Overall-scanning method yield: ~30% KK  KK (K -, K 0 )

8. 8 Overall scanning Concept and Key technologies; (1). 3-dimensional scanning under optical microscopic view. (2). Image process to find multi-vertex shape in emulsion. * High speed is required * The method is also useful to find calibration sources such as, alpha decays, single lambda hypernuclei. * This method will be applied to E07 after regular analysis with hybrid method.

9. 9 Difference of Gaussian Binalization Gaussian filter Original image Filter for bold tracksThinning Prob. Hough Trans.Vertexing kernel size = 17pix x20 Objective (NA0.35) 1 pix = ~0.6 micron threshold ~= peak*0.2 dist-edge-to-edge = 15pix N_Tracks > 3 polygon area > 1000pix resolution = 1degree threshold = 16 pix / line contour length > 5pix area > 10pix (smoothed – source) if negative, brightness=0 (2). Image process J.Yoshida et al., JPS Conf. Proc., (2014) 1.013070

10. 10 Blurred brightness(x) = Blurred - Raw brightness(x,y) = B - A A. raw imageB. blurred if negative, brightness = 0 Raw x x brightness(x)

11. 11 Difference of Gaussian Binalization Gaussian filter Original image Filter for bold tracksThinning Prob. Hough Trans.Vertexing kernel size = 17pix x20 Objective (NA0.35) 1 pix = ~0.6 micron threshold ~= peak*0.2 resolution = 1degree threshold = 16 pix / line contour length > 5pix area > 10pix (smoothed – source) if negative, brightness=0 (2). Image process J.Yoshida et al., JPS Conf. Proc., (2014) 1.013070 dist-edge-to-edge = 8micron N_Tracks > 3 polygon area > 300micron 2 tuned by Nagara event and some alpha decays

12. 12 ・ extracted images of vertex-like-object

13. 13 example :E373 mod86 pl7 scanned volume: 2.2mm * 10mm * 0.9mm detected candidates: 3496 vertex: 361 misrecognition : 3135 Beam Interaction: 329 Alpha decay ： 32 crossing‐over of 2tracks: * Parameter tuning. * Recognition under a higher magnificent optics after 1 st level selection. * And so on. Beam Int. Alpha decay Eye check for extracted vertexes SingleHyper: 6

14. 14 high resolution CMOS 2048*358 pixel high frame rate 800fps wide F.O.V. x20 dry lens (NA0.35) 1142*200 micron 2 Piezoelectric drive stroke500 micron period5Hz picture40picts /cycle Continuously stage moving (1). A dedicated scanning system （ Stage#7,8 ） collaborate with UNIOPT Co. emulsion plate objective lens Piezoelectric drive camera Designed speed: 10mm*10mm*0.9mm / 2min. = ~40 hours @plate (340*335*0.9[mm 3 ]) To accomplish scanning of ~1000 films within a few year.

15. 15 Xaxis Yaxis Field Of View : 0.2*1.1 [mm 2 ] stage motion in X-Y plane (top view) 1.0 mm / sec 1 2 3 4 200msec /cycle Yaxis Zaxis stage motion in Y-Z plane (cross sectional view) 1.0 mm / sec 40 picts. * Exhaustively scanning by a computer-controlled optical microscope. * Continuous stage drive to save damping time of vibration.

16. 16 Difference of Gaussian Binalization Gaussian filter Original image Filter for bold tracksThinning Prob. Hough Trans.Vertexing kernel size = 17pix x20 Objective (NA0.35) 1 pix = ~0.6 micron threshold ~= peak*0.2 dist-edge-to-edge = 15pix N_Tracks > 3 polygon area > 1000pix resolution = 1degree threshold = 16 pix / line contour length > 5pix area > 10pix (smoothed – source) if negative, brightness=0 (2). Image process J.Yoshida et al., JPS Conf. Proc., (2014) 1.013070 * These are processed in real-time by CPU&GPU (5msec/pict.) * Data is stored in HDDs

17. * Stage drive, piezoelectric, camera are synchronized. Trigger timing is proper. * Missed trigger and troubles in data transfer < 3% 17 Quality checking for scanned data Exhaustiveness of image taking pict.ID number_of_’1’_pixel base Tiled binalized images. 200micron*1140micron*3views The same layer ID Time or Y Z Trigger timing surface 50views -> 40pictures 1 10 20 30 40 trigger

18. Found events; ~3000 alpha decays ~700 single hypernuclear event 7 three-vertexes candidates. A typical twin-single-lambda- hypernuclear event (Kiso) PrototypeUpgraded High-speed Since~201120142013 Stage Camera 100fps CCD800fps CMOS Z-drive Stepping motorPiezoelectric Optics Field of View0.11*0.13mm 2 0.18*0.21mm 2 0.20*1.14mm 2 Speed[mm 3 /h]2.613.12700 SiteGifu-univ.Gifu-univ.Gifu-univ. Toho-univ,JapanGNU,Korea GNU,Korea Scanned vol.~5.0ccjust started17.4cc 10  m 18 Operation

19. summary * Overall scanning A new searching method for double lambda hypernucleus in emulsion. Concept: high speed 3D scanning & image recognition * The current status Scanning software, Image process is basically successful. Improvement of detection efficiency and S/N ratio is being carried out. *Operation In operation in Gifu-univ., Toho-univ., Japan, GNU, Korea. ~700 candidates of single hypernuclear ~7 3-vertexes candidates. A typical twin-single-lambda- hypernuclear event (Kiso) 19

20. 20

21. Difference of Gaussian Binalization Gaussian filter Raw image Filter for bold tracksThinning Prob. Hough Trans.Vertexing kernel size = 17pix x20 Objective (NA0.35) 1 pix = ~0.6 micron threshold ~= peak*0.2 dist-edge-to-edge = 15pix N_Tracks > 3 polygon area > 1000pix resolution = 1degree threshold = 16 pix / line contour length > 5pix area > 10pix (smoothed – source) if negative, brightness=0 Image process JPS Conf. Proc., (2014) 1.013070

22. 22 Piezo Ctrl. BNC USB PiezoElec. CMOS Camera Grabber Board Host PC TRG PCI & PCI-E GPGPU Stage Ctrl. CameraLink Base & Full Main Board USB command Time or StageYaxis Z Emulsion thickness TRG: start sequential shooting optics vibration of focal plane driven by Piezoelectricity Synclonization between piezoelectricity and camera 400us 3.5V (LVTTL) 400us 5.0V

23. 23 Z-Axis (Optics) Grabber Board Host PC PCI & PCI-E GPGPU Stage Ctrl. Main Board Serial command Motor Driver (3-axes) LED Driver X,Y-Axis (Stage) LED Light Stage control

24. 24 CMOS Camera Grabber Board Host PC PCI & PCI-E GPGPU (GTX680) Stage Ctrl. CPU Corei7 3960X RAM External HDD Chipset X79 eSATA (100MB/s) (1) Camera -> grabber_board -> RAM (2) RAM -> GPGPU (3) Difference_of_Gaussians on GPGPU (4) GPGPU -> RAM (5) Binalization on CPU (6) RAM -> External HDD (7) Image process on another computer Data transmission 2048*358 pix 8bit-depth 2048*358 pix 1bit-depth シリアル

25. 25 Overall scanning Stage size: 35cm*35cm (Nikon. ) 45cm*45cm (Uniopt. ) Field of View: 115micron*135micron(x50 objective lens) ほかにも、乾板中にランダムに存在するキャリブレーションソース アルファ崩壊、シングルハイパーも探索したい。 そこで ・原子核乾板の全体積を光学顕微鏡で走査し、 (1) 高速顕微鏡画像取得の開発 ・少なくとも 1 つの分岐点をもつパターンを検出 (2) 画像解析の開発

26. 26 Phase I : 技術開発 兼 E373 乾板の再解析 先の実験（ KEK E373 ）の乾板を用いて技術開発 E373 乾板の全体積をスキャンし、 従来比 10 倍、 70 例のダブル Λ ハイパー核検出をねらう Phase II : E07 実験解析のアシスト キャリブレーションソース：アルファ崩壊の探索高速化 Phase III : E07 乾板の再解析 E07 乾板の全体積をスキャンし、 プロポーザル比 10 倍、 10 3 例 のダブル Λ ハイパー核検出をねらう Overall Scanning と解析のストラテジー