Simulation of orientational effects in crystals with structural defects through DYNECHARM++

Bagli, E.; Guidi, V.

doi:10.1016/j.nimb.2015.03.072

Cited by 4 publications

(4 citation statements)

References 24 publications

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“…Indeed, the need for a crystal free from dislocation is especially relevant for the LHC. In particular, it is important that the crystal is free from dislocation, while point defects contribute less to dechanneling [ 55 , 62 , 65 ].…”

Section: Discussionmentioning

confidence: 99%

“…Moreover, since the beam would be perpendicular to the damaged surfaces and would pass through them, the particle trajectories would be affected by multiple Coulomb scattering, which eventually leads to a lowering of the channeling efficiency. In order to have a large channeling efficiency of a 7 TeV energy beam, it is estimated that the maximum number of dislocations should not be larger than [ 55 ]. Thus, an etching process to remove the part of the crystal rich of defects was performed.…”

Section: Crystal Manufacturing and Bendingmentioning

confidence: 99%

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Bent crystals for efficient beam steering of multi TeV-particle beams

et al. 2018

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Charged particle beams can be manipulated by exploiting the channeling phenomenon in bent crystals. Two plate-like crystals, bent by mechanical holders, were manufactured and characterised for such purpose at the Sensor and Semiconductor Laboratory in Ferrara, Italy. An anticlastic curvature was obtained for these crystals, achieving a steering angle of the order of 1 mrad, which is about 20 times larger than the values currently achieved for the bent crystals used in the LHC for collimation experiments. Finally, a Geant4 simulation was performed to study the channeling efficiency for beam deflection with 400 GeV/c and 7 TeV/c proton beams. Such crystals represent technological progress in the development of bent crystals for highly energetic charged particle beams. Indeed, they are designed to impart an angular kick to a 7 TeV/c proton beam with unprecedented high efficiency. Therefore, this study demonstrates the possibility of realizing bent crystals suitable for beam extraction in high-energy hadron accelerators, such as LHC or at the future FCC. A further series of studies should be conducted to evaluate the channeling efficiency and the deflection angle of the realized crystals via a charged proton beam.

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Section: Discussionmentioning

confidence: 99%

Section: Crystal Manufacturing and Bendingmentioning

confidence: 99%

Bent crystals for efficient beam steering of multi TeV-particle beams

et al. 2018

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“…Radiation generates pointlike defects, which negligibly affect the channeling efficiency (≪ 0.01%) [52][53][54]. Indeed, the number of pointlike defects has to be a part per mill of the total number of atoms in the crystal to spoil coherent effects [54,55]. For instance, Si was proven to be radiation hard for channeling with 450-GeV=c protons during a full year of continuous operations to a peak fluence of 5 × 10 20 particles per cm 2 [56], a value by far larger than 2.2 × 10 14 integrated intensity in the LHC in 2012 [57].…”

mentioning

confidence: 99%

“…In order to provide an insight into the influence of defects on channeling and volume reflections, a Monte Carlo simulation was worked out via DYNECHARM++ code [58], which incorporates a subroutine to account for the presence of crystal defects [55]. Defects can be grouped according to their dimensionality in the lattice on which they act, i.e., pointlike (interstitial atoms and vacancies), linear (dislocations), two-dimensional (stacking faults), and three-dimensional (amorphous clusters) defects [52].…”

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confidence: 99%

Orientational Coherent Effects of High-Energy Particles in aLiNbO3Crystal

et al. 2015

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A bent lithium niobate strip was exposed to a 400-GeV/c proton beam at the external lines of CERN Super Proton Synchrotron to probe its capabilities versus coherent interactions of the particles with the crystal such as channeling and volume reflection. Lithium niobate (LiNbO3) exhibits an interplanar electric field comparable to that of Silicon (Si) and remarkable piezoelectric properties, which could be exploited for the realization of piezo-actuated devices for the control of high-energy particle beams. In contrast to Si and germanium (Ge), LiNbO3 shows an intriguing effect; in spite of a low channeling efficiency (3%), the volume reflection maintains a high deflection efficiency (83%). Such discrepancy was ascribed to the high concentration (10(4) per cm2) of dislocations in our sample, which was obtained from a commercial wafer. Indeed, it has been theoretically shown that a channeling efficiency comparable with that of Si or Ge would be attained with a crystal at low defect concentration (less than ten per cm2). To better understand the role of dislocations on volume reflection, we have worked out computer simulation via dynecharm++ Monte Carlo code to study the effect of dislocations on volume reflection. The results of the simulations agree with experimental records, demonstrating that volume reflection is more robust than channeling in the presence of dislocations.

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Outline of Structural Metallurgy Relevant to Corrosion☆

Procter

Mahi

2017

Reference Module in Materials Science and Materials Engineering

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Simulation of orientational effects in crystals with structural defects through DYNECHARM++

Cited by 4 publications

References 24 publications

Bent crystals for efficient beam steering of multi TeV-particle beams

Bent crystals for efficient beam steering of multi TeV-particle beams

Orientational Coherent Effects of High-Energy Particles in aLiNbO3Crystal

Outline of Structural Metallurgy Relevant to Corrosion☆

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