A. Bogdanov

Publications (6)0 Total impact

• Source

  Available from: Robert Chehab

  Article: Summary of experimental studies at CERN on a positron source using crystal effects

  X. Artru, V. Baier, K. Beloborodov, A. Bogdanov, A Bukin, S Burdin, R. Chehab, M Chevallier, R. Cizeron, D. Dauvergne, [......], V. Kulibaba, P. Lautesse, J. Major, J C Poizat, A. Potylitsin, J. Remillieux, S. Serednyakov, V Shary, V. Strakhovenko, C. Sylvia
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  ABSTRACT: New kind of positron sources for future linear colliders, where the converter is a tungsten crystal oriented on the <111> axis, has been studied at CERN in the WA103 experiment. In such sources the photons which create the $e^+ e^-$ pairs result from channeling radiation and coherent bremsstrahlung. In this experiment electron beams of 6 and 10 GeV were sent on different kinds of targets: a 4 mm thick crystal, a 8 mm thick crystal and a compound taraget (4 mm crystal + 4 mm amorphous disk). An amorphous tungsten target 20 mm thick was also used for comparison with the 8 mm crystal. Tracks of outgoing charged particles were detected and analyzed by a drift chamber in a magnetic field. The energy and angle spectra of the positrons were obtained for energies up to 150 MeV and angles up to 30 degrees. The measured positron distribution in momentum space (longitudinal versus transverse) is also presented, giving a full momentum space description of the source. Results on outgoing photons are also presented. A significant enhancement of both photon and positron production is clearly observed. At 10 GeV incident energy, the positron enhancement factor is 4 for the 4 mm crystal, about 2 for the 8 mm crystal. Besides, the simulation code for the crystal processes is validated by a quite good agreement between the simulated and experimental spectra, both for positrons and photons.
  07/2005;
• Source

  Available from: T. V. Dimova

  Article: Experimental Determination of the Characteristics of a Positron Source Using Channeling

  R. Chehab, R. Cizeron, C. Sylvia, V. Baier, K. Beloborodov, A Bukin, S Burdin, T. Dimova, A. Drozdetsky, V Druzhinin, [......], A. Jejcic, P. Keppler, J. Major, L Gatignon, G. Bochek, V. Kulibaba, N. Maslov, A. Bogdanov, A. Potylitsin, I. Vnukov
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  ABSTRACT: Numerical simulations and `proof of principle' experiments showed clearly the interest of using crystals as photon generators dedicated to intense positron sources for linear colliders. An experimental investigation, using a 10 GeV secondary electron beam, of the SPS-CERN, impinging on an axially oriented thick tungsten crystal, has been prepared and operated between May and August 2000. After a short recall on the main features of positron sources using channeling in oriented crystals, the experimental set-up is described. A particular emphasis is put on the positron detector made of a drift chamber, partially immersed in a magnetic field. The enhancement in photon and positron production in the aligned crystal have been observed in the energy range 5 to 40 GeV, for the incident electrons, in crystals of 4 and 8 mm as in an hybrid target. The first results concerning this experiment are presented hereafter.
  09/2000;
• Article: Experiment with a crystal-assisted positron source using 6 and 10 GeV electrons

  X. Artru, V. Baier, K. Beloborodov, G. Bochek, A. Bogdanov, A. Bozhenok, A. Bukin, S. Burdin, R. Chehab, M. Chevallier, [......], J. Major, N. Maslov, J.-C. Poizat, A. Potylitsin, J. Remillieux, S. Serednyakov, V. Shary, V. Strakhovenko, C. Sylvia, I. Vnukov
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  ABSTRACT: Axially oriented crystals, penetrated by high-energy electrons, are powerful photon sources and, hence, intense positron sources. Such kinds of positron sources have been studied experimentally at CERN, with the tertiary electron beam of the SPS having an energy of 6 and 10 GeV. Four and eight millimeters thick tungsten crystals and a compound target made of a 4 mm crystal followed by a 4 mm amorphous disk were used with an orientation along the 〈111〉 axis. The positrons were detected by a drift chamber, partially immersed in a magnetic field. The reconstructed trajectories allowed the determination of their energy and angular spectra. Significant enhancements were observed for the crystal source when compared to the amorphous one. The gain was about 3 for the 4 mm target and about 2 for the 8 mm and the compound targets. These preliminary results are described after short presentations of the experimental set-up and of the method of track reconstruction.
  Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms.
• Source

  Available from: Robert Chehab

  Article: Experimental determination of the characteristics of a positron source using channeling: addendum to P309 and request for beam time in 2001

  R. Chehab, R. Cizeron, C. Sylvia, V. Baier, K. I. Beloborodov, A Bukin, S. V. Burdin, T. V. Dimova, A. A. Drozdetsky, V. P. Druzhinin, [......], A. Jejcic, P. Keppler, J V Major, L Gatignon, G L Bochek, V. Kulibaba, N I Maslov, A. Bogdanov, A P Potylitsin, I E Vnukov
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  ABSTRACT: Numerical simulations and `proof of principle' experiments showed clearly the interest of using crystals as photon generators dedicated to intense positron sources for linear colliders. An experimental investigation, using a 10 GeV secondary electron beam, of the SPS-CERN, impinging on an axially oriented thick tungsten crystal, has been prepared and operated between May and August 2000. After a short recall on the main features of positron sources using channeling in oriented crystals, the experimental set-up is described. A particular emphasis is put on the positron detector made of a drift chamber, partially immersed in a magnetic field. The enhancement in photon and positron production in the aligned crystal have been observed in the energy range 5 to 40 GeV, for the incident electrons, in crystals of 4 and 8 mm as in an hybrid target. The first results concerning this experiment are presented hereafter.
• Article: Experimental Study of a Crystal Positron Source

  R. Chehab, R. Cizeron, C. Sylvia, V. Baier, K. Beloborodov, A Bukin, S Burdin, T. Dimova, A. Drozdetsky, V Druzhinin, [......], A. Jejcic, P. Keppler, J. Major, L Gatignon, G. Bochek, V. Kulibaba, N. Maslov, A. Bogdanov, A. Potylitsin, I. Vnukov
  Physics Letters B, v.525, 41-48 (2002).
• Source

  Available from: Robert Chehab

  Article: Experimental determination of the positron source emittance for a crystal target

  R. Chehab, S Burdin, R. Cizeron, C. Sylvia, V. Baier, K. Belobodorov, A Bukin, T. Dimova, A. Drozdetsky, V Druzhinin, [......], A. Jejcic, M. Dubrovin, P. Keppler, J. Major, L Gatignon, G. Bochek, V. Kulibaba, A. Bogdanov, A. Potylitsin, I. Vnukov