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Doç. Dr. Erhan Pesen VIII. Uluslararası Katılımlı Parçacık Hızlandırıcıları ve Detektörleri Yaz Okulu 14-09-2012 Bodrum.

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Presentation on theme: "Doç. Dr. Erhan Pesen VIII. Uluslararası Katılımlı Parçacık Hızlandırıcıları ve Detektörleri Yaz Okulu 14-09-2012 Bodrum."— Presentation transcript:

1 Doç. Dr. Erhan Pesen VIII. Uluslararası Katılımlı Parçacık Hızlandırıcıları ve Detektörleri Yaz Okulu Bodrum

2  Early detectors are Image Detectors. Principle: What you see what you get.  Could Chambers  Bubble Chambers  Nuclear Emulsions Doç. Dr. Erhan Pesen Bodrum

3  Also called Wilson chamber  The cloud chamber contains a supersaturated vapour of water or alcohol.  A charged particle interacting with the mixture, creates ions.  The ions act as condensation nuclei around which a mist (cloud of particles) will form  High energy alpha and beta particles leave a track due to the ions they produce along their path  If a magnetic field is applied positively and negatively charged particles will curve in opposite directions  TQk TQk  2aQo 2aQo The images at left are typical of those obtained by Wilson (C. T. R. Wilson, Proc. Roy. Soc. (London), 87, 292 (1912)).

4 Doç. Dr. Erhan Pesen Bodrum  Positron discovery, Carl Anderson 1933 [Nobel price 1936]  Magnetic field Gauss, chamber diameter 15cm.  A 63 MeV positron passes through a 6mm lead leaving the plate with energy 23MeV.  The ionization of this particle, and its behavior in passing through the foil was the same as those of an electron but with positive charge

5 Doç. Dr. Erhan Pesen Bodrum  Muons were discovered by Carl D. Anderson and Seth Neddermeyer at Caltech in 1936 with a cloud chamber while studying cosmic radiation

6 Doç. Dr. Erhan Pesen Bodrum  A bubble chamber is a vessel filled with a superheated transparent liquid (Hydrogen at T=30K). A charge particle initiate boiling.  Urban history: Glaser was inspired by the bubbles in a glass of beer  The size of the chambers grew quickly:  – 1954: 6.4cm  – 1954: 10cm  – 1956: 25cm  – 1959: 183cm  – 1963: 203cm  – 1973: 370cm  Some disadvantages:  – It cannot be triggered  – Low rate capability  – The photographic readout: for data analysis one had to look through millions of photos Invented in 1952 by Glaser (1960 Nobel Prize in Physics)

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8  Gargamelle, a very large heavy-liquid (freon) chamber constructed at Ecole Polytechnique in Paris, came to CERN in  2 m in diameter, 4 m long and filled with Freon at 20 atm, in 2 T B field  Gargamelle in 1973 was the tool that permitted the discovery of neutral currents.

9 Doç. Dr. Erhan Pesen Bodrum  Nuclear Emulsion particle detectors feature the highest position and angular resolution in the measurement of tracks of ionizing particles.  Nuclear Emulsion, used to record the tracks of charged particles, is a photographic plate.  A photographic emulsion consists of a large number of small crystals of silver halide, mostly bromide.  The sensitivity to light has allowed silver halides to become the basis of modern photographic materials.  A silver halide is one of the compounds formed between silver and one of the halogens — silver bromide (AgBr), chloride (AgCl), iodide (AgI), and three forms of silver fluorides  The method of recording tracks of charged particles in photographic plates is based upon two achievements of modern technology, the photographic emulsion and the optical microscopes

10 Doç. Dr. Erhan Pesen Bodrum  A nuclear emulsion plate is a photographic plate with a thick emulsion layer and uniform grain size.  – It records the tracks of charged particles passing through  – It produce a cumulative record  – The plates must be developed before the tracks can be observed.  In 1937, Marietta Blau and Hertha Wambacher discovered nuclear disintegration stars due to spallation in nuclear emulsions exposed to cosmic radiation at a height of 2,300 meters above sea level

11 Doç. Dr. Erhan Pesen Bodrum  The pion was discovered in Nuclear emulsion techniques, Powell 1947; Nobel Prize 1950  Discovered in 1947 in nuclear emulsions exposed to cosmic rays, and they showed that it decay to a muon and an unseen partner.  The constant range of the decay muon from the pion decay indicate that this is a two body decay

12 Doç. Dr. Erhan Pesen Bodrum  First evidence of the decay of the Kaon into 3 Pions was found in 1949 in Nuclear emulsion (by G. Rochester at Manchester)

13 Doç. Dr. Erhan Pesen Bodrum -Ω--Ω-

14  Today > 200 particles listed in PDG:  27 have cτ > 1 μm  they can be seen as tracks in a detectors  13 have cτ < 500 μm  displaced vertices

15  The only one that survives in Early Image Detectors  No time resolution  No vertex location information  Very good spatial resolution  Very good track, two track resolution (grain size ~1μm)  Events are recorded and stays forever Doç. Dr. Erhan Pesen Bodrum

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17 Active target Calorimeter Spectrometer Air-core magnet

18 Doç. Dr. Erhan Pesen Bodrum  Photographic developer is a chemical amplifier acting on the latent image.  A rather complex physics-chemical process is able to transform those grains with a suitable development centre into metallic silver.  After development, a silver halide emulsion is placed in a second bath, called as fixer which dissolves the unaffected grains of silver halide but leaves the small black granules of silver.  Finally, The plate is washed and dried.  Emulsion Films drying after development

19 Doç. Dr. Erhan Pesen Bodrum track 90  m plastic backing 350  m (175  m) emulsion sheet CCD camera CCD camera microscope stroke tomographic image X50 magnification ~3  m focal depth 150x150  m view Tracks reconstructed by a hardware video processor frame to frame emulsion grains coincidence 350  m (175  m) emulsion sheet emulsion plate

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21 Network data storage UTS = a machine for general scanning: ~1 cm 2 /hour

22 Doç. Dr. Erhan Pesen Bodrum Track segments from 8 plates overlapped At least 2-segment connected tracks Eliminate passing- through tracks Reconstruct full vertex topology ‘Emulsion is the mass storage’ (Prof.K.Niwa) ~7000TB

23 Doç. Dr. Erhan Pesen Bodrum Zoom D+D+   h

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25  Mainly designed for the direct search of ν τ appearance in the pure ν µ CNGS beam from CERN to Gran Sasso(732km).  Based on the use of Emulsion Cloud Chambers (ECCs) and of electronic detectors(Hybrid Detector).  In an ECC the nuclear emulsion films act as very high precision tracking detectors, and are interleaved with plates of lead.  The brick, is made of 57 emulsion films interleaved with 56 lead foils of 1 mm thickness. It has 128x102x79mm 3, and weighs 8.3 kg. Emulsion Cloud Chamber

26 Doç. Dr. Erhan Pesen Bodrum  The distinctive feature of ν τ charged-current interactions is the production of a short-lived τ lepton (cτ =87 µm).  This is achieved in OPERA using the Nuclear Emulsion technique that features an unrivaled spatial resolution (≤ 1 µm).  OPERA Detector is a hybrid (emulsion+electronics) with a modular structure. 2 SuperModules=2*(31walls+1spectrometer) Total Mass: 1766 Tons. # of Bricks=  ECC measures: Kink of Tau, Momentum(via MCS), Electromagnetic Shower, dE/dX, e/π separation, Event Kinematics,Vertex Location, τ ID,  Magnetic Spectrometer: μ ID, charge and momentum.Target tracker: Trigger and localiza ν interactions.

27 Doç. Dr. Erhan Pesen Bodrum  The required area of emulsion is of order of 100,000 m 2 s  It is needed high-speed automatic scanning systems.  Scanning power is 10cm 2 /h at LHEP  Emulsions are scanned at Europe and Japanese scanning Labs.

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30  To obtain medical images of the patient’s body (proton radiography).  Proton radiography allows obtaining images directly proportional to the average density of the traversed material.  Emulsion detector is cheaper and easier to install and remove.

31 Doç. Dr. Erhan Pesen Bodrum  Telescope observes 1. Brightness (Magnitute) 2. Color (Wavelength) 3. Direction of the light  Emulsion Measures 1. Event Rate (Flux) 2. Energy (Momentum) 3. Direction of gamma-ray photon Visible (Palomar) 2 mrad Ultra Violet (UIT) Reconstructed Tracks Gamma Shower

32 Doç. Dr. Erhan Pesen Bodrum muons ECC Muon source with a well-known energy spectrum for different zenith angles. A well-understood muon detector. The information from counting muon events at different arriving angles can be used to infer on the matter profile.

33 Doç. Dr. Erhan Pesen Bodrum

34 LEP Tunnel


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