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Bagli E, De Salvador D, Bacci L, Sgarbossa F, Bandiera L, Camattari R, Germogli G, Mazzolari A, Sytov A, Guidi G. Enhancement of the Inelastic Nuclear Interaction Rate in Crystals via Antichanneling. Phys Rev Lett 2019; 123:044801. [PMID: 31491266 DOI: 10.1103/physrevlett.123.044801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 05/24/2019] [Indexed: 06/10/2023]
Abstract
The interaction rate of a charged particle beam with the atomic nuclei of a target varies significantly if the target has a crystalline structure. In particular, under specific orientations of the target with respect to the incident beam, the probability of inelastic interaction with nuclei can be enhanced with respect to the unaligned case. This effect, which can be named antichanneling, can be advantageously used in the cases where the interaction between beam and target has to be maximized. Here we propose to use antichanneling to increase the radioisotope production yield via cyclotron. A dedicated set of experimental measurements was carried out at the INFN Legnaro Laboratories with the AN2000 and CN accelerators to prove the existence of the antichanneling effect. The variation of the interaction yield at hundreds of keV to MeV energies was observed by means of sapphire and indium phosphide crystals, achieving an enhancement of the interaction rate up to 73% and 25%, respectively. Such a result may pave the way to the development of a novel type of nozzle for the existing cyclotrons, which can exploit crystalline materials as targets for radioisotope production, especially to enhance the production rate for expensive prime materials with minor upgrades of the current instrumentation.
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Affiliation(s)
- E Bagli
- INFN Sezione di Ferrara, Via Saragat 1, 44122 Ferrara, Italy
| | - D De Salvador
- INFN Sezione di Legnaro, Viale dell'Università 2, 35020 Legnaro PD, Italy
- Dipartimento di Fisica e Astronomia, Università degli Studi di Padova, Via Marzolo, 8, 35131 Padova, Italy
| | - L Bacci
- Dipartimento di Fisica e Astronomia, Università degli Studi di Padova, Via Marzolo, 8, 35131 Padova, Italy
| | - F Sgarbossa
- Dipartimento di Fisica e Astronomia, Università degli Studi di Padova, Via Marzolo, 8, 35131 Padova, Italy
| | - L Bandiera
- INFN Sezione di Ferrara, Via Saragat 1, 44122 Ferrara, Italy
| | - R Camattari
- INFN Sezione di Ferrara, Via Saragat 1, 44122 Ferrara, Italy
| | - G Germogli
- INFN Sezione di Ferrara, Via Saragat 1, 44122 Ferrara, Italy
| | - A Mazzolari
- INFN Sezione di Ferrara, Via Saragat 1, 44122 Ferrara, Italy
| | - A Sytov
- INFN Sezione di Ferrara, Via Saragat 1, 44122 Ferrara, Italy
- Institute for Nuclear Problems, Belarusian State University, 220030 Minsk, Belarus
| | - G Guidi
- COMECER SpA, Via Maestri del Lavoro 90, 48014 Alberazzo-Canalvecchio, Italy
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2
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Sgarbossa F, Carturan SM, De Salvador D, Rizzi GA, Napolitani E, Maggioni G, Raniero W, Napoli DR, Granozzi G, Carnera A. Monolayer doping of germanium by phosphorus-containing molecules. Nanotechnology 2018; 29:465702. [PMID: 30168801 DOI: 10.1088/1361-6528/aade30] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The DPP (diethyl 1-propylphosphonate) and ODPA (octadecylphosphonic acid) molecules are studied as precursors for the monolayer doping (MLD) of germanium. Their adsorption behaviour is investigated, revealing different physicochemical interactions between the phosphorus-containing molecules and the Ge surfaces. It is discovered that DPP adsorption occurs after the oxidation of Ge surface, while the ODPA undergoes chemisorption on -H terminated surfaces. Quantitative phosphorus analysis demonstrates that in the first case more than one monolayer is formed (from 2 to 4), while in the second a single monolayer is formed. Moreover, the analysis of phosphorus diffusion from the surface layers into the Ge matrix reveals that conventional thermal annealing processes are not suitable for Ge injection due to a higher activation energy of the process in comparison with silicon. On the contrary, pulsed laser melting is effective in forming a doped layer, owing to the precursor's decomposition under UV light.
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Affiliation(s)
- F Sgarbossa
- Department of Physics and Astronomy, Università degli Studi di Padova, Via Marzolo n 8, I-35131 Padova, Italy. Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, Viale dell'Università n 2, I-35020 Legnaro (PD), Italy
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Bandiera L, Tikhomirov VV, Romagnoni M, Argiolas N, Bagli E, Ballerini G, Berra A, Brizzolari C, Camattari R, De Salvador D, Haurylavets V, Mascagna V, Mazzolari A, Prest M, Soldani M, Sytov A, Vallazza E. Strong Reduction of the Effective Radiation Length in an Axially Oriented Scintillator Crystal. Phys Rev Lett 2018; 121:021603. [PMID: 30085729 DOI: 10.1103/physrevlett.121.021603] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Indexed: 06/08/2023]
Abstract
We measured a considerable increase of the emitted radiation by 120 GeV/c electrons in an axially oriented lead tungstate scintillator crystal, if compared to the case in which the sample was not aligned with the beam direction. This enhancement resulted from the interaction of particles with the strong crystalline electromagnetic field. The data collected at the external lines of the CERN Super Proton Synchrotron were critically compared to Monte Carlo simulations based on the Baier-Katkov quasiclassical method, highlighting a reduction of the scintillator radiation length by a factor of 5 in the case of beam alignment with the [001] crystal axes. The observed effect opens the way to the realization of compact electromagnetic calorimeters or detectors based on oriented scintillator crystals in which the amount of material can be strongly reduced with respect to the state of the art. These devices could have relevant applications in fixed-target experiments, as well as in satellite-borne γ telescopes.
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Affiliation(s)
- L Bandiera
- INFN Sezione di Ferrara and Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Ferrara Via Saragat 1, 44122 Ferrara, Italy
| | - V V Tikhomirov
- Institute for Nuclear Problems, Belarusian State University, 220030 Minsk, Belarus
| | - M Romagnoni
- INFN Sezione di Ferrara and Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Ferrara Via Saragat 1, 44122 Ferrara, Italy
| | - N Argiolas
- INFN Sezione di Legnaro and Dipartimento di Fisica e Astronomia, Università degli Studi di Padova, 35131 Padova, Italy
| | - E Bagli
- INFN Sezione di Ferrara and Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Ferrara Via Saragat 1, 44122 Ferrara, Italy
| | - G Ballerini
- INFN Sezione di Milano Bicocca and Dipartimento di Scienza e Alta Tecnologia, Università degli Studi dell'Insubria Via Valleggio, 22100 Como, Italy
| | - A Berra
- INFN Sezione di Milano Bicocca and Dipartimento di Scienza e Alta Tecnologia, Università degli Studi dell'Insubria Via Valleggio, 22100 Como, Italy
| | - C Brizzolari
- INFN Sezione di Milano Bicocca and Dipartimento di Scienza e Alta Tecnologia, Università degli Studi dell'Insubria Via Valleggio, 22100 Como, Italy
| | - R Camattari
- INFN Sezione di Ferrara and Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Ferrara Via Saragat 1, 44122 Ferrara, Italy
| | - D De Salvador
- INFN Sezione di Legnaro and Dipartimento di Fisica e Astronomia, Università degli Studi di Padova, 35131 Padova, Italy
| | - V Haurylavets
- Institute for Nuclear Problems, Belarusian State University, 220030 Minsk, Belarus
| | - V Mascagna
- INFN Sezione di Milano Bicocca and Dipartimento di Scienza e Alta Tecnologia, Università degli Studi dell'Insubria Via Valleggio, 22100 Como, Italy
| | - A Mazzolari
- INFN Sezione di Ferrara and Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Ferrara Via Saragat 1, 44122 Ferrara, Italy
| | - M Prest
- INFN Sezione di Milano Bicocca and Dipartimento di Scienza e Alta Tecnologia, Università degli Studi dell'Insubria Via Valleggio, 22100 Como, Italy
| | - M Soldani
- INFN Sezione di Milano Bicocca and Dipartimento di Scienza e Alta Tecnologia, Università degli Studi dell'Insubria Via Valleggio, 22100 Como, Italy
| | - A Sytov
- INFN Sezione di Ferrara and Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Ferrara Via Saragat 1, 44122 Ferrara, Italy
- Institute for Nuclear Problems, Belarusian State University, 220030 Minsk, Belarus
| | - E Vallazza
- INFN Sezione di Trieste, Via Valerio 2, 34149 Trieste, Italy
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Bagli E, Guidi V, Mazzolari A, Bandiera L, Germogli G, Sytov AI, De Salvador D, Argiolas A, Bazzan M, Carnera A, Berra A, Bolognini D, Lietti D, Prest M, Vallazza E. Orientational Coherent Effects of High-Energy Particles in a LiNbO3 Crystal. Phys Rev Lett 2015; 115:015503. [PMID: 26182106 DOI: 10.1103/physrevlett.115.015503] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Indexed: 06/04/2023]
Abstract
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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Affiliation(s)
- E Bagli
- INFN Sezione di Ferrara, Dipartimento di Fisica e Scienze della Terra, Università di Ferrara Via Saragat 1, 44100 Ferrara, Italy
| | - V Guidi
- INFN Sezione di Ferrara, Dipartimento di Fisica e Scienze della Terra, Università di Ferrara Via Saragat 1, 44100 Ferrara, Italy
| | - A Mazzolari
- INFN Sezione di Ferrara, Dipartimento di Fisica e Scienze della Terra, Università di Ferrara Via Saragat 1, 44100 Ferrara, Italy
| | - L Bandiera
- INFN Sezione di Ferrara, Dipartimento di Fisica e Scienze della Terra, Università di Ferrara Via Saragat 1, 44100 Ferrara, Italy
| | - G Germogli
- INFN Sezione di Ferrara, Dipartimento di Fisica e Scienze della Terra, Università di Ferrara Via Saragat 1, 44100 Ferrara, Italy
| | - A I Sytov
- INFN Sezione di Ferrara, Dipartimento di Fisica e Scienze della Terra, Università di Ferrara Via Saragat 1, 44100 Ferrara, Italy
| | - D De Salvador
- Dipartimento di Fisica e Astronomia, Università di Padova, Via Marzolo 8, 35131 Padova, Italy and INFN Laboratori Nazionali di Legnaro, Viale dell'Università 2, 35020 Legnaro, Italy
| | - A Argiolas
- Dipartimento di Fisica e Astronomia, Università di Padova, Via Marzolo 8, 35131 Padova, Italy and INFN Laboratori Nazionali di Legnaro, Viale dell'Università 2, 35020 Legnaro, Italy
| | - M Bazzan
- Dipartimento di Fisica e Astronomia, Università di Padova, Via Marzolo 8, 35131 Padova, Italy and INFN Laboratori Nazionali di Legnaro, Viale dell'Università 2, 35020 Legnaro, Italy
| | - A Carnera
- Dipartimento di Fisica e Astronomia, Università di Padova, Via Marzolo 8, 35131 Padova, Italy and INFN Laboratori Nazionali di Legnaro, Viale dell'Università 2, 35020 Legnaro, Italy
| | - A Berra
- Università dell'Insubria, via Valleggio 11, 22100 Como, Italy and INFN Sezione di Milano Bicocca, Piazza della Scienza 3, 20126 Milano, Italy
| | - D Bolognini
- Università dell'Insubria, via Valleggio 11, 22100 Como, Italy and INFN Sezione di Milano Bicocca, Piazza della Scienza 3, 20126 Milano, Italy
| | - D Lietti
- Università dell'Insubria, via Valleggio 11, 22100 Como, Italy and INFN Sezione di Milano Bicocca, Piazza della Scienza 3, 20126 Milano, Italy
| | - M Prest
- Università dell'Insubria, via Valleggio 11, 22100 Como, Italy and INFN Sezione di Milano Bicocca, Piazza della Scienza 3, 20126 Milano, Italy
| | - E Vallazza
- INFN Sezione di Trieste, Via Valerio 2, 34127 Trieste, Italy
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Lietti D, Backe H, Bagli E, Bandiera L, Berra A, Carturan S, De Salvador D, Germogli G, Guidi V, Lauth W, Mazzolari A, Prest M, Vallazza E. The experimental setup of the Interaction in Crystals for Emission of RADiation collaboration at Mainzer Mikrotron: Design, commissioning, and tests. Rev Sci Instrum 2015; 86:045102. [PMID: 25933892 DOI: 10.1063/1.4916367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Silicon/germanium flat/bent crystals are thin devices able to efficiently deflect charged particle GeV-energy beams up to a few hundreds of μrad; moreover, high intensity photons can be efficiently produced in the so-called Multi-Volume Reflection (MVR) and Multiple Volume Reflections in One Crystal (MVROC) conditions. In the last years, the research interest in this field has moved to the dynamic studies of light negative leptons in the low energy range: the possibility to deflect negative particles and to produce high intensity γ sources via the coherent interactions with crystals in the sub-GeV energy range has been proved by the ICE-RAD (Interaction in Crystals for Emission of RADiation) Collaboration at the MAinzer MIkrotron (MAMI, Germany). This paper describes the setup used by the ICE-RAD experiment for the crystals characterization (both in terms of deflection and radiation emission properties): a high precision goniometer is used to align the crystals with the incoming beam, while a silicon based profilometer and an inorganic scintillator reconstruct, respectively, the particle position and the photon spectra after the samples. The crystals manufacturing process and their characterization, the silicon profilometer commissioning at the CERN PS T9 beamline, and the commissioning of the whole setup installed at MAMI are presented.
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Affiliation(s)
- D Lietti
- Università degli Studi dell'Insubria, Via Valleggio 11, 22100 Como, Italy
| | - H Backe
- Institut für Kernphysik der Universität Mainz, D-55099 Mainz, Germany
| | - E Bagli
- Università degli Studi di Ferrara, Via Saragat 1, 44100 Ferrara, Italy
| | - L Bandiera
- Università degli Studi di Ferrara, Via Saragat 1, 44100 Ferrara, Italy
| | - A Berra
- Università degli Studi dell'Insubria, Via Valleggio 11, 22100 Como, Italy
| | - S Carturan
- Università degli Studi di Padova, Via Marzolo 8, 35131 Padova, Italy
| | - D De Salvador
- Università degli Studi di Padova, Via Marzolo 8, 35131 Padova, Italy
| | - G Germogli
- Università degli Studi di Ferrara, Via Saragat 1, 44100 Ferrara, Italy
| | - V Guidi
- Università degli Studi di Ferrara, Via Saragat 1, 44100 Ferrara, Italy
| | - W Lauth
- Institut für Kernphysik der Universität Mainz, D-55099 Mainz, Germany
| | - A Mazzolari
- Università degli Studi di Ferrara, Via Saragat 1, 44100 Ferrara, Italy
| | - M Prest
- Università degli Studi dell'Insubria, Via Valleggio 11, 22100 Como, Italy
| | - E Vallazza
- INFN Sezione di Trieste, Via Valerio 2, 34127 Trieste, Italy
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Mastromatteo M, Arduca E, Napolitani E, Nicotra G, De Salvador D, Bacci L, Frascaroli J, Seguini G, Scuderi M, Impellizzeri G, Spinella C, Perego M, Carnera A. Quantification of phosphorus diffusion and incorporation in silicon nanocrystals embedded in silicon oxide. SURF INTERFACE ANAL 2014. [DOI: 10.1002/sia.5578] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- M. Mastromatteo
- CNR-IMM MATIS and Dipartimento di Fisica e Astronomia; Università degli Studi di Padova; Via Marzolo, 8 I-35131 Padova Italy
| | - E. Arduca
- CNR-IMM Lab MDM; Via Olivetti, 2 I-20041 Agrate Brianza (MI) Italy
| | - E. Napolitani
- CNR-IMM MATIS and Dipartimento di Fisica e Astronomia; Università degli Studi di Padova; Via Marzolo, 8 I-35131 Padova Italy
| | - G. Nicotra
- CNR-IMM; Z.I. VIII Strada 5 I-95121 Catania Italy
| | - D. De Salvador
- CNR-IMM MATIS and Dipartimento di Fisica e Astronomia; Università degli Studi di Padova; Via Marzolo, 8 I-35131 Padova Italy
| | - L. Bacci
- CNR-IMM MATIS and Dipartimento di Fisica e Astronomia; Università degli Studi di Padova; Via Marzolo, 8 I-35131 Padova Italy
| | - J. Frascaroli
- CNR-IMM Lab MDM; Via Olivetti, 2 I-20041 Agrate Brianza (MI) Italy
| | - G. Seguini
- CNR-IMM Lab MDM; Via Olivetti, 2 I-20041 Agrate Brianza (MI) Italy
| | - M. Scuderi
- CNR-IMM; Z.I. VIII Strada 5 I-95121 Catania Italy
| | - G. Impellizzeri
- CNR-IMM MATIS at Dipartimento di Fisica ed Astronomia; Università degli Studi di Catania; Via S. Sofia 64 I-95132 Catania Italy
| | - C. Spinella
- CNR-IMM; Z.I. VIII Strada 5 I-95121 Catania Italy
| | - M. Perego
- CNR-IMM Lab MDM; Via Olivetti, 2 I-20041 Agrate Brianza (MI) Italy
| | - A. Carnera
- CNR-IMM MATIS and Dipartimento di Fisica e Astronomia; Università degli Studi di Padova; Via Marzolo, 8 I-35131 Padova Italy
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Mazzolari A, Bagli E, Bandiera L, Guidi V, Backe H, Lauth W, Tikhomirov V, Berra A, Lietti D, Prest M, Vallazza E, De Salvador D. Steering of a sub-GeV electron beam through planar channeling enhanced by rechanneling. Phys Rev Lett 2014; 112:135503. [PMID: 24745437 DOI: 10.1103/physrevlett.112.135503] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Indexed: 06/03/2023]
Abstract
We report the observation of efficient steering of a 855 MeV electron beam at MAMI (MAinzer MIkrotron) facilities by means of planar channeling and volume reflection in a bent silicon crystal. A 30.5 μm thick plate of (211) oriented Si was bent to cause quasimosaic deformation of the (111) crystallographic planes, which were used for coherent interaction with the electron beam. The experimental results are analogous to those recorded some years ago at energy higher than 100 GeV, which is the only comparable study to date. Monte Carlo simulations demonstrated that rechanneling plays a considerable role in a particle's dynamics and hinders the spoiling of channeled particles. These results allow a better understanding of the dynamics of electrons subject to coherent interactions in a bent silicon crystal in the sub-GeV energy range, which is relevant for realization of innovative x-ray sources based on channeling in periodically bent crystals.
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Affiliation(s)
- A Mazzolari
- INFN Sezione di Ferrara, Dipartimento di Fisica e Scienze della Terra, Università di Ferrara Via Saragat 1, 44100 Ferrara, Italy
| | - E Bagli
- INFN Sezione di Ferrara, Dipartimento di Fisica e Scienze della Terra, Università di Ferrara Via Saragat 1, 44100 Ferrara, Italy
| | - L Bandiera
- INFN Sezione di Ferrara, Dipartimento di Fisica e Scienze della Terra, Università di Ferrara Via Saragat 1, 44100 Ferrara, Italy
| | - V Guidi
- INFN Sezione di Ferrara, Dipartimento di Fisica e Scienze della Terra, Università di Ferrara Via Saragat 1, 44100 Ferrara, Italy
| | - H Backe
- Institut für Kernphysik der Universität Mainz, Fachbereich Physik, Mathematik und Informatik, D-55099 Mainz, Germany
| | - W Lauth
- Institut für Kernphysik der Universität Mainz, Fachbereich Physik, Mathematik und Informatik, D-55099 Mainz, Germany
| | - V Tikhomirov
- Research Institute for Nuclear Problems, Belarusian State University, Bobruiskaya street, 11, Minsk 220030, Belarus
| | - A Berra
- Università dell'Insubria, via Valleggio 11, 22100 Como, Italy and INFN Sezione di Milano Bicocca, Piazza della Scienza 3, 20126 Milano, Italy
| | - D Lietti
- Università dell'Insubria, via Valleggio 11, 22100 Como, Italy and INFN Sezione di Milano Bicocca, Piazza della Scienza 3, 20126 Milano, Italy
| | - M Prest
- Università dell'Insubria, via Valleggio 11, 22100 Como, Italy and INFN Sezione di Milano Bicocca, Piazza della Scienza 3, 20126 Milano, Italy
| | - E Vallazza
- INFN Sezione di Trieste, Via Valerio 2, 34127 Trieste, Italy
| | - D De Salvador
- INFN Laboratori Nazionali di Legnaro, Viale dell'Università 2, 35020 Legnaro, Italy and Dipartimento di Fisica, Università di Padova, Via Marzolo 8, 35131 Padova, Italy
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Bandiera L, Bagli E, Guidi V, Mazzolari A, Berra A, Lietti D, Prest M, Vallazza E, De Salvador D, Tikhomirov V. Broad and intense radiation accompanying multiple volume reflection of ultrarelativistic electrons in a bent crystal. Phys Rev Lett 2013; 111:255502. [PMID: 24483748 DOI: 10.1103/physrevlett.111.255502] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Indexed: 06/03/2023]
Abstract
The radiation emitted by 120 GeV/c electrons traversing a single bent crystal under multiple volume reflection orientation is investigated. Multiple volume reflection in one crystal occurs as a charged particle impacts on a bent crystal at several axial channeling angles with respect to a crystal axis. The resulting energy-loss spectrum of electrons was very intense over the full energy range up to the nominal energy of the beam. As compared to the radiation emission by an individual volume reflection, the energy-loss spectrum is more intense and peaks at an energy 3 times greater. Experimental results are compared to a theoretical approach based on the direct integration of the quasiclassical Baier and Katkov formula. In this way, it is possible to determine the mean number of photons emitted by each electron and, thus, to extract the single-photon spectrum, which is broad and intense. The soft part of the radiation spectrum is due to the contribution of coherent interaction between electrons and several reflecting planes intersecting the same crystal axis, whereas the hard part is mainly connected to coherent bremsstrahlung induced by correlated scattering of electrons by atomic strings (string of strings scattering and radiation). The radiation generation by multiple volume reflection takes place over a broad angular range of the incident beam with respect to coherent bremsstrahlung and channeling radiation in straight crystals. Therefore, this type of radiation can be exploited for applications, such as beam dump and collimation devices for future linear colliders.
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Affiliation(s)
- L Bandiera
- INFN Sezione di Ferrara, Dipartimento di Fisica, Università di Ferrara, Via Saragat 1, 44122 Ferrara, Italy
| | - E Bagli
- INFN Sezione di Ferrara, Dipartimento di Fisica, Università di Ferrara, Via Saragat 1, 44122 Ferrara, Italy
| | - V Guidi
- INFN Sezione di Ferrara, Dipartimento di Fisica, Università di Ferrara, Via Saragat 1, 44122 Ferrara, Italy
| | - A Mazzolari
- INFN Sezione di Ferrara, Dipartimento di Fisica, Università di Ferrara, Via Saragat 1, 44122 Ferrara, Italy
| | - A Berra
- Università dell'Insubria, Via Valleggio 11, 22100 Como, Italy, and INFN Sezione di Milano Bicocca, Piazza della Scienza 3, 20126 Milano, Italy
| | - D Lietti
- Università dell'Insubria, Via Valleggio 11, 22100 Como, Italy, and INFN Sezione di Milano Bicocca, Piazza della Scienza 3, 20126 Milano, Italy
| | - M Prest
- Università dell'Insubria, Via Valleggio 11, 22100 Como, Italy, and INFN Sezione di Milano Bicocca, Piazza della Scienza 3, 20126 Milano, Italy
| | - E Vallazza
- INFN Sezione di Trieste, Via Valerio 2, 34127 Trieste, Italy
| | - D De Salvador
- INFN Laboratori Nazionali di Legnaro, Viale dell'Università 2, 35020 Legnaro, Italy, and Dipartimento di Fisica, Università Di Padova, Via Marzolo 8, 35131 Padova, Italy
| | - V Tikhomirov
- Research Institute for Nuclear Problems, Belarusian State University, Minsk, Belarus
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9
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Bagli E, Bandiera L, Guidi V, Mazzolari A, De Salvador D, Maggioni G, Berra A, Lietti D, Prest M, Vallazza E, Abrosimov NV. Coherent effects of high-energy particles in a graded Si(1-x)Ge(x) crystal. Phys Rev Lett 2013; 110:175502. [PMID: 23679744 DOI: 10.1103/physrevlett.110.175502] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Revised: 01/18/2013] [Indexed: 06/02/2023]
Abstract
A graded Si(1-x)Ge(x) crystal has been manufactured for operation with high-energy protons to excite coherent interactions of the particles with the crystal such as channeling and volume reflection. The crystal had the shape of a parallelepiped though its (111) atomic planes were curved at a radius of 25.6 m because of the graded Ge content. The crystal was exposed to a 400 GeV/c proton beam at the external lines of CERN Super Proton Synchrotron to probe its capability to steer high-energy particles. Measured deflection efficiency was 62.0% under planar channeling and 96.0% under volume reflection. Such values are critically compared to their counterparts for a standard bent Si crystal under peer conditions. A Monte Carlo simulation of the dynamics of channeled and volume reflected particles in a graded crystal including the effect of Ge impurities and of lattice dislocations has been carried out. We found that the effect of crystal imperfections spoiled the efficiency of channeling while it negligibly affected the performance of volume reflection. We finally propose the usage of the graded crystal as a primary scatterer to aid halo collimation for the new generation of hadronic machines. As a unique feature, a properly cut graded crystal circumvents the problem of the miscut angle, which is currently a severe limitation for implementation of crystal-assisted collimation.
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Affiliation(s)
- E Bagli
- INFN Sezione di Ferrara, Dipartimento di Fisica e Scienze della Terra, Università di Ferrara Via Saragat 1, 44100 Ferrara, Italy
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Cowern NEB, Simdyankin S, Ahn C, Bennett NS, Goss JP, Hartmann JM, Pakfar A, Hamm S, Valentin J, Napolitani E, De Salvador D, Bruno E, Mirabella S. Extended point defects in crystalline materials: Ge and Si. Phys Rev Lett 2013; 110:155501. [PMID: 25167283 DOI: 10.1103/physrevlett.110.155501] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2012] [Indexed: 06/03/2023]
Abstract
B diffusion measurements are used to probe the basic nature of self-interstitial point defects in Ge. We find two distinct self-interstitial forms--a simple one with low entropy and a complex one with entropy ∼30 k at the migration saddle point. The latter dominates diffusion at high temperature. We propose that its structure is similar to that of an amorphous pocket--we name it a morph. Computational modeling suggests that morphs exist in both self-interstitial and vacancylike forms, and are crucial for diffusion and defect dynamics in Ge, Si, and probably many other crystalline solids.
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Affiliation(s)
- N E B Cowern
- School of Electrical and Electronic Engineering, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
| | - S Simdyankin
- School of Electrical and Electronic Engineering, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
| | - C Ahn
- School of Electrical and Electronic Engineering, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
| | - N S Bennett
- School of Electrical and Electronic Engineering, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
| | - J P Goss
- School of Electrical and Electronic Engineering, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom
| | - J-M Hartmann
- CEA, LETI, Minatec Campus, 38054 Grenoble, France
| | - A Pakfar
- ST Microelectronics, 850 rue Jean Monnet, 38920 Crolles, France
| | - S Hamm
- Mattson Thermal Products GmbH, Daimlerstrasse 10, 89160 Dornstadt, Germany
| | - J Valentin
- Probion Analysis, 37 rue de Fontenay, 92220 Bagneux, France
| | - E Napolitani
- CNR-IMM-MATIS and Dipartimento di Fisica, Università di Padova, Via Marzolo 8, 35131 Padova, Italy
| | - D De Salvador
- CNR-IMM-MATIS and Dipartimento di Fisica, Università di Padova, Via Marzolo 8, 35131 Padova, Italy
| | - E Bruno
- CNR-IMM-MATIS and Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sofia 64, 95123 Catania, Italy
| | - S Mirabella
- CNR-IMM-MATIS and Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sofia 64, 95123 Catania, Italy
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Guidi V, Mazzolari A, De Salvador D, Bacci L. Deflection of MeV protons by an unbent half-wavelength silicon crystal. Phys Rev Lett 2012; 108:014801. [PMID: 22304263 DOI: 10.1103/physrevlett.108.014801] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2011] [Indexed: 05/31/2023]
Abstract
The interaction of a 2 MeV proton beam with an ultrathin unbent Si crystal was studied through simulation and experiment. Crystal thickness along the beam was set at 92 nm, i.e., at half the oscillation wavelength of the protons in the crystal under planar channeling condition. As the nominal beam direction is inclined by less than the critical angle for planar channeling with respect to the crystal planes, under-barrier particles undergo half an oscillation and exit the crystal with the reversal of the transverse momenta; i.e., the protons are "mirrored" by the crystal planes. Over-barrier particles suffer deflection, too, to a direction opposite that of mirroring with a dynamics similar to that of volume reflection in a bent crystal. On the strength of such coherent interactions, charged particle beams can be efficiently steered through an ultrathin unbent crystal by the same physical processes as for thicker bent crystals.
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Affiliation(s)
- V Guidi
- INFN Sezione di Ferrara and Dipartimento di Fisica, Università di Ferrara, Via Saragat 1/C, 44122 Ferrara, Italy.
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Ferrari C, Lazzarini L, Salviati G, Natali M, Berti M, De Salvador D, Drigo A, Rossetto G, Torzo G. A Systematic Investigation of Strain Relaxation, Surface Morphology and Defects in Tensile and Compressive InGaAs/InP Layers. ACTA ACUST UNITED AC 2011. [DOI: 10.1557/proc-578-285] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
AbstractThe results of a systematic investigation by transmission electron microscopy (TEM), cathodoluminescence (CL), Rutherford backscattering (RBS), X-ray diffraction and topography and scanning force microscopy (SFM) techniques on several InGaAs/InP compressive and tensile strained layers covering the misfit range from −2.3 to 1.5×10−2 and grown by the metal organic vapor phase epitaxy (MOVPE) technique are reported. In compressively strained films the same dependence for the residual strain vs the film thickness as for the InGaAs/GaAs is found whereas a different strain release rate and different extended defects are found in tensile stressed InGaAs alloy. In particular in tensile stressed samples, grooves, planar defects and cracks are present in addition to the interfacial network of misfit dislocations. The correlation between the observed planar defects and the mechanisms of strain relaxation in the case of tensile strained layers is discussed.
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Bisognin G, De Salvador D, Napolitani E, Berti M, Polimeni A, Capizzi M, Rubini S, Martelli F, Franciosi A. High-resolution X-ray diffractionin situstudy of very small complexes: the case of hydrogenated dilute nitrides. J Appl Crystallogr 2008. [DOI: 10.1107/s0021889807068094] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
In this work it is demonstrated howin situhigh-resolution X-ray diffraction (HRXRD), performed during thermal annealing and employing a conventional laboratory source, can be used to obtain information on the evolution kinetics of very small complexes formed in an epitaxial layer. HRXRD allows the measurement of changes in the lattice parameter of the layer (i.e.the layer strain) with different annealing strategies (by linear temperature ramp or isothermal annealing). On the basis of these data and using an appropriate model, the dissolution energy values of the complexes can be extracted. The underlying idea is that every type of complex present in the layer gives a specific lattice strain which varies under annealing, allowing their evolution to be traced accurately. As an example, this methodology is applied to the study of N–H complexes formed in hydrogen-irradiated GaAs1−xNx/GaAs layers.
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Napolitani E, De Salvador D, Storti R, Carnera A, Mirabella S, Priolo F. Room temperature migration of boron in crystalline silicon. Phys Rev Lett 2004; 93:055901. [PMID: 15323711 DOI: 10.1103/physrevlett.93.055901] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2004] [Indexed: 05/24/2023]
Abstract
We demonstrate that substitutional B in silicon can migrate even at room temperature and below, stimulated by a high interstitial flux. Once mobile B is formed, it migrates for long distances with a diffusivity >5 x 10(-13) cm(2)/s, until it assumes an immobile configuration with a migration length independent of the temperature. This phenomenon is present during secondary ion mass spectrometry (SIMS) analyses of B profiles, altering the profile during the analysis itself. These results shed new light on all the data based on SIMS analyses and reported in literature in the last decades.
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Affiliation(s)
- E Napolitani
- MATIS-INFM and Dipartimento di Fisica, Università di Padova, Via Marzolo 8, I-35131 Padua, Italy.
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