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On PRISMA project (proposal)

On PRISMA project (proposal). Yuri V. Stenkin INR RAS. The Project aims. Why PRISMA? PRI mary S pectrum M easurement A rray The main aim is: TO SOLVE THE “KNEE PROBLEM” Other aims: cosmic rays spectra and mass composition cosmic ray sources applied Geophysical measurements.

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On PRISMA project (proposal)

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  1. On PRISMA project (proposal) Yuri V. Stenkin INR RAS Yu. Stenkin, UHECR'2008

  2. The Project aims • Why PRISMA? • PRImary Spectrum Measurement Array • The main aim is: TO SOLVE THE “KNEE PROBLEM” • Other aims: • cosmic rays spectra and mass composition • cosmic ray sources • applied Geophysical measurements Yu. Stenkin, UHECR'2008

  3. History & Motivation Why we need a new project? 1. The “knee problem” is a milestone of cosmic ray physics. 2. Very few experiments have been designed specially for that and KASCADE (KArlsruhe Shower Core and Array DEtector) is the best one. 3. The problem still exists. Yu. Stenkin, UHECR'2008

  4. EAS method Yu. Stenkin, UHECR'2008

  5. 1. The “knee problem” The problem is exactly 50-years old! In 1958 there was published a paper (G.V. Kulikov & G.B. Khristiansen) claiming the knee existence in cosmic ray energy spectrum. They observed a sharp change of slope in EAS size spectrum and proposed a model describing this effect as an evidence of existence of 2 sources of c. r.: Galactic and Metagalactic ones. But, from the beginning and up to now there exist alternative explanations of this effect (S.I.Nikolsky, Kazanas & Nikolaidis, A.A.Petrukhin, Yu.V. Stenkin). Yu. Stenkin, UHECR'2008

  6. Examples of alternative explanations Petrukhin Stenkin New processes EAS method systematic knee knee Primary energy EAS energy Primary energy E Primary energy Missing energy Missing energy Yu. Stenkin, UHECR'2008

  7. EAS components equilibrium No of particles Break of equilibrium Break in attenuation “knee” in Ne spectrum Depth in atmosphere From Hayakawa manual on cosmic ray physics Yu. Stenkin, UHECR'2008

  8. When the break occurs? • At E~100 TeV / nucleon • For p: 100 TeV • For Fe: 5 PeV (just the knee region) This figures are sequences of : Lint= 90 g/cm2 in air the Earth’s atmosphere thickness =1030 g/ cm2 (depending on altitude) For details see: Yu.Stenkin, Yadernaya Phys., 71 (2008), 99 Yu. Stenkin, UHECR'2008

  9. 2. Existing experiments • KASCADE It gave many interesting results. BUT, it did not answer the question on the knee origin and thus, It has not solved the knee problem! Moreover, the problem became even less clear….(see G. Schatz.Proc. 28th ICRC, Tsukuba, (2003), 97 or Yu. Stenkin. Proc. 29th ICRC, Pune (2005), v.6, 621) Yu. Stenkin, UHECR'2008

  10. KASCADE -> KASCADE-Grande Yu. Stenkin, UHECR'2008

  11. KASCADE hadronic calorimeter Yu. Stenkin, UHECR'2008

  12. KASCADE group connected visible knee in PeV region with c. r. protons. Tibet AS experiment results contradict this hypothesis: they connect the knee with iron primary. In this case there should be the iron knee at E~1017 eV. - Nobody saw this. C. R. should consist only of heavy nuclei at E>1017 eV or one has to adjust many parameters to make full compensation. - Nobody saw this. It contradicts emulsion chamber experiments (Pamir) and air luminescence data (Hi Res). Yu. Stenkin, UHECR'2008

  13. Compilation of experimental data (astro-ph/0507018) Yu. Stenkin, UHECR'2008

  14. KASCADE EAS h-size spectra “knee”??? Yu. Stenkin, UHECR'2008

  15. A. Haungs, J. Kempa et al. (KASCADE) Report FZKA6105 (1998); Nucl. Phys. B (Proc. Suppl.) 75A (1999), 248 Yu. Stenkin, UHECR'2008

  16. KASCADE is very precise classical instrument for EAS study. It would be difficult and useless to try to make better array. to make a device based on new principles (asymmetrical answer) On my opinion the only way is: Yu. Stenkin, UHECR'2008

  17. PRISMA would be the answer. Prism PRISMA Yu. Stenkin, UHECR'2008

  18. New principles The main EAS component is: hadrons Therefore, let us concentrate mostly on the hadronic component Bun, instead of huge and expensive hadron calorimeter of fixed area, let us make simple, inexpensive and of unlimited area detector. How this could be done? Yu. Stenkin, UHECR'2008

  19. New Methods 2 new methods have been developed in our Lab. 1st method is based on thermal neutrons “vapour” accompanying EAS Yu. Stenkin, UHECR'2008

  20. Yu. Stenkin, UHECR'2008

  21. en-detector design PMT plastic housing ZnS(Ag) is a unique scin- tillator for heavy particles detection: 6Li(n,a)3H+4.8 MeV Scintillator: ZnS(Ag)+6LiF Similar to that using in neutron imaging technique 160,000 photons per capture Yu. Stenkin, UHECR'2008

  22. The detector is almost insensitive to single charged particles. But, it can measure the number N of charged particles if N>5. Yu. Stenkin, UHECR'2008

  23. Thermal neutron time distributions Multicom Prototype, Baksan Prisma prototype, Moscow Yu. Stenkin, UHECR'2008

  24. Another advantage of this detector is a possibility to measure thermal neutron flux of low intensity and its variations Yu. Stenkin, UHECR'2008

  25. 2d new method: The Muon Detector as a 1-layer hadronic calorimeter: Yu. Stenkin, UHECR'2008

  26. This picture represents a density map as measured by Carpet (left, shown in LOG scale) and by MD (right, linear scale in relativistic particles). (Detector in the center show a particle density of ρc=8*1.1252/0.5=5800 m-2. jet of (26+17)/2=21.5 particles per m2 in MD. Jet size is very narrow (~1 m) with normal rather low density around it and second: the distance from the EAS core is large enough and equal to 48 m. r jet = 21.5 /m2 r core= 5800 / m2 Yu. Stenkin, UHECR'2008

  27. Preliminary Baksan data: hadrons at R=47m Yu. Stenkin, UHECR'2008

  28. Muon/hadron ratio distribution Preliminary data Yu. Stenkin, UHECR'2008

  29. Carpet: 400*1m2 en-detectors grid with spacing of 5 m Central muon detector: 400*1m2 plastic scinillators Muon detector tunnels: 1200*1m2 plastic scintillators Outer trigger detectors: 4*25*1m2 plastic scintillators Yu. Stenkin, UHECR'2008

  30. M-C simulations. CORSIKA 6.501 (HDPM, Gheisha6) Yu. Stenkin, UHECR'2008

  31. M-C simulations. CORSIKA 6.501 (HDPM, Gheisha6)+array A map of an event in neutrons Ne= 407158 Nmu= 794 E0/1TeV= 355.0245 x0= -4.448307 y0= -27.31079 TETA= 13.80 FI= 161.49 Z= 3094504. Part_type= 5626 Yu. Stenkin, UHECR'2008

  32. M-C Yu. Stenkin, UHECR'2008

  33. Main features: • Range in primary energy: from ~10 TeV to ~30 PeV • energy resolution: ~ 10% • angular resolution: ~ 1o • core location: < 2.5 m • capability to measure independently: Ne, Nh, Nm Yu. Stenkin, UHECR'2008

  34. Location • Collaboration Institutions • budget • altitude (high altitude is preferable) It depends on: Yu. Stenkin, UHECR'2008

  35. Involved Institutions: 1. Institute for Nuclear Research, Moscow 2. MEPhI, Moscow 3. Skobeltsyn Institute, MSU, Moscow 4. 5. To be continued... The collaboration is open for other participants. You are welcome! Yu. Stenkin, UHECR'2008

  36. Thank you! Yu. Stenkin, UHECR'2008

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