| 1. |
- Scandale, W., et al.
(author)
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Manipulation of negatively charged beams VIA coherent effects in bent crystals
- 2010
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In: IPAC 2010. - : ACFA. - 9789290833529 ; , s. 4398-4400
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Conference paper (peer-reviewed)abstract
- We review the experimental evidences we recorded with volume reflection and planar and axial channelings with negatively charged particles beam. High deflection efficiency was observed in all cases. The experiment was carried out by the UA9 collaboration in the external lines of the CERN SPS with a secondary beam of 150 GeV/c negative particles.
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| 2. |
- Scandale, W., et al.
(author)
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Deflection of high-energy negative particles in a bent crystal through axial channeling and multiple volume reflection stimulated by doughnut scattering
- 2010
-
In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 693:5, s. 545-550
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Journal article (peer-reviewed)abstract
- Different kinds of deflection in a silicon crystal bent along the 〈111〉 axis was observed for 150 GeV/. c negative particles, mainly π- mesons, at one of the secondary beams of the CERN SPS. The whole beam was deflected to one side in quasi-bound states of doughnut scattering (DSB) by atomic strings with the efficiency (95.4 ± 0.2)% and with the peak position close to the bend crystal angle, α=185 μrad. It was observed volume capture of π- mesons into the DSB states with a probability higher than 7%. A beam deflection opposite to the crystal bend was observed for some orientations of the crystal axis due to doughnut scattering and subsequent multiple volume reflections of π- mesons by different bent planes crossing the axis. © 2010 Elsevier B.V.
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| 3. |
- Scandale, W., et al.
(author)
-
Multiple volume reflections of high-energy protons in a sequence of bent silicon crystals assisted by volume capture
- 2010
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In: Physics Letters B. - : Elsevier. - 0370-2693 .- 1873-2445. ; 688:4-5, s. 284-288
-
Journal article (peer-reviewed)abstract
- Multiple volume reflections of the 400 GeV / c proton beam by the sequence of fourteen bent silicon strips has been studied at the CERN SPS. The sequence is close to be parallel that is the spread of the strip orientation angles is much smaller than their bend angle and eleven strips working coherently in the regime of volume reflections deflected the beam by 110 μrad with the efficiency 88%, which is significantly larger than the estimation based on independent reflections. The mechanism giving the efficiency increase has been studied by simulation. It appears that many particles volume captured in one of the strips take part in volume reflections in the subsequent ones. Such a crystal multi reflector can be successfully used as a primary collimator for the beam halo collimation of high-energy accelerators.
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