Records |
Author |
Blanes, S.; Casas, F.; Oteo, J.A.; Ros, J. |
Title |
A pedagogical approach to the Magnus expansion |
Type |
Journal Article |
Year |
2010 |
Publication |
European Journal of Physics |
Abbreviated Journal |
Eur. J. Phys. |
Volume |
31 |
Issue |
4 |
Pages |
907-918 |
Keywords |
|
Abstract |
Time-dependent perturbation theory as a tool to compute approximate solutions of the Schrodinger equation does not preserve unitarity. Here we present, in a simple way, how the Magnus expansion (also known as exponential perturbation theory) provides such unitary approximate solutions. The purpose is to illustrate the importance and consequences of such a property. We suggest that the Magnus expansion may be introduced to students in advanced courses of quantum mechanics. |
Address |
[Blanes, S.] Univ Politecn Valencia, Inst Matemat Multidisciplinar, E-46022 Valencia, Spain, Email: serblaza@imm.upv.es |
Corporate Author |
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Thesis |
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Publisher |
Iop Publishing Ltd |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
0143-0807 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
ISI:000279393800024 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
no |
Call Number |
IFIC @ pastor @ |
Serial |
259 |
Permanent link to this record |
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Author |
Modamio, V.; Valiente-Dobon, J.J.; Jaworski, G.; Huyuk, T.; Triossi, A.; Egea, J.; Di Nitto, A.; Soderstrom, P.A.; Ros, J.A.; de Angelis, G.; de France, G.; Erduran, M.N.; Erturk, S.; Gadea, A.; Gonzalez, V.; Kownacki, J.; Moszynski, M.; Nyberg, J.; Palacz, M.; Sanchis, E.; Wadsworthm, R. |
Title |
Digital pulse-timing technique for the neutron detector array NEDA |
Type |
Journal Article |
Year |
2015 |
Publication |
Nuclear Instruments & Methods in Physics Research A |
Abbreviated Journal |
Nucl. Instrum. Methods Phys. Res. A |
Volume |
775 |
Issue |
|
Pages |
71-76 |
Keywords |
Digital timing; Constant fraction discriminator; Liquid scintillator; BC501A; Neutron detector; NEDA |
Abstract |
A new digital pulse-timing algorithm, to be used with the future neutron detector array NEDA, has been developed and tested. The time resolution of four 5 in diameter photomultiplier tubes (XP4512, R4144, R11833-100, and ET9390-kb), coupled to a cylindrical 5 in by 5 in BC501A liquict scintillator detector was measured by employing digital sampling electronics and a constant fraction discriminator (CFD) algorithm. The zero crossing of the CM algorithm was obtained with a cubic spline interpolation, which was continuous up to the second derivative. The performance of the algorithm was studied at sampling rates of 500 MS/s and 200 MS/s. The time resolution obtained with the digital electronics was compared to the values acquired with a standard analog CFD. The result of this comparison shows that the time resolution from the analog and the digital measurements at 500 MS/s and at 200 MS/s are within 15% for all the tested photomultiplier tubes. |
Address |
[Modamio, V.; Valiente-Dobon, J. J.; Triossi, A.; de Angelis, G.] Ist Nazl Fis Nucl, Lab Nazl Legnaro, I-35020 Legnaro, Italy, Email: victor.modamio@lnl.infn.it |
Corporate Author |
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Thesis |
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Publisher |
Elsevier Science Bv |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0168-9002 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
|
Notes |
WOS:000348040900011 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
2093 |
Permanent link to this record |
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Author |
Magan, D.L.P.; Caballero, L.; Domingo-Pardo, C.; Agramunt-Ros, J.; Albiol, F.; Casanovas, A.; Gonzalez, A.; Guerrero, C.; Lerendegui-Marco, J.; Tarifeño-Saldivia, A. |
Title |
First tests of the applicability of gamma-ray imaging for background discrimination in time-of-flight neutron capture measurements |
Type |
Journal Article |
Year |
2016 |
Publication |
Nuclear Instruments & Methods in Physics Research A |
Abbreviated Journal |
Nucl. Instrum. Methods Phys. Res. A |
Volume |
823 |
Issue |
|
Pages |
107-119 |
Keywords |
Neutron capture cross-sections; gamma-ray imaging; Total energy detectors; Pulse-height weighting technique; Time-of-flight method |
Abstract |
In this work we explore for the first time the applicability of using gamma-ray imaging in neutron capture measurements to identify and suppress spatially localized background. For this aim, a pinhole gamma camera is assembled, tested and characterized in terms of energy and spatial performance. It consists of a monolithic CeBr3 scintillating crystal coupled to a position-sensitive photomultiplier and readout through an integrated circuit AMIC2GR. The pinhole collimator is a massive carven block of lead. A series of dedicated measurements with calibrated sources and with a neutron beam incident on a Au-197 sample have been carried out at n_TOF, achieving an enhancement of a factor of two in the signal-to-background ratio when selecting only those events coming from the direction of the sample. |
Address |
[Perez Magan, D. L.; Caballero, L.; Domingo-Pardo, C.; Agramunt-Ros, J.; Albiol, F.; Tarifeno-Saldivia, A.] Univ Valencia, CSIC, IFIC, E-46071 Valencia, Spain, Email: domingo@ific.uv.es |
Corporate Author |
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Thesis |
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Publisher |
Elsevier Science Bv |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0168-9002 |
ISBN |
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Medium |
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Area |
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Expedition |
|
Conference |
|
Notes |
WOS:000374661600015 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
no |
Call Number |
IFIC @ pastor @ |
Serial |
2665 |
Permanent link to this record |
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Author |
Ibanez-Rosello, B.; Bautista-Ballesteros, J.A.; Candela-Juan, C.; Villaescusa, J.I.; Ballester, F.; Vijande, J.; Perez-Calatayud, J. |
Title |
Evaluation of the shielding in a treatment room with an electronic brachytherapy unit |
Type |
Journal Article |
Year |
2017 |
Publication |
Journal of Radiological Protection |
Abbreviated Journal |
J. Radiol. Prot. |
Volume |
37 |
Issue |
2 |
Pages |
N5-N12 |
Keywords |
Esteya; electronic brachytherapy; shielding; radiation protection |
Abstract |
Esteya (R) (Elekta Brachytherapy, Veenendaal, The Netherlands) is an electronic brachytherapy (eBT) system based on a 69.5 kVp x-ray source and a set of collimators of 1 to 3 cm in diameter, used for treating non-melanoma skin cancer lesions. This study aims to estimate room shielding requirements for this unit. The non-primary (scattered and leakage) ambient dose equivalent rates were measured with a Berthold LB-133 monitor (Berthold Technologies, Bad Wildbad, Germany). The latter ranges from 17 mSv h(-1) at 0.25 m distance from the x-ray source to 0.1 mSv h(-1) at 2.5 m. The necessary room shielding was then estimated following US and some European guidelines. The room shielding for all barriers considered was below 2 mmPb. The dose to a companion who, exceptionally, would stay with the patient during all treatment was estimated to be below 1 mSv if a leaded apron is used. In conclusion, Esteya shielding requirements are minimal. |
Address |
[Ibanez-Rosello, Blanca; Ignacio Villaescusa, Juan] La Fe Univ, Radioprotect Dept, E-46026 Valencia, Spain, Email: blanca.ibanez.rosello@gmail.com |
Corporate Author |
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Thesis |
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Publisher |
Iop Publishing Ltd |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
ISSN |
0952-4746 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000413778600001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
no |
Call Number |
IFIC @ pastor @ |
Serial |
3344 |
Permanent link to this record |
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Author |
Botella-Soler, V.; Oteo, J.A.; Ros, J. |
Title |
Coexistence of periods in a bifurcation |
Type |
Journal Article |
Year |
2012 |
Publication |
Chaos, Solitons & Fractals |
Abbreviated Journal |
Chaos Solitons Fractals |
Volume |
45 |
Issue |
5 |
Pages |
681-686 |
Keywords |
|
Abstract |
A particular type of order-to-chaos transition mediated by an infinite set of coexisting neutrally stable limit cycles of different periods is studied in the Varley-Gradwell-Hassell population model. We prove by an algebraic method that this kind of transition can only happen for a particular bifurcation parameter value. Previous results on the structure of the attractor at the transition point are here simplified and extended. |
Address |
[Botella-Soler, V.; Oteo, J. A.; Ros, J.] Univ Valencia, Dept Fis Teor, E-46100 Valencia, Spain, Email: vicente.botella@uv.es |
Corporate Author |
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Thesis |
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Publisher |
Pergamon-Elsevier Science Ltd |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0960-0779 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000303785300014 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
no |
Call Number |
IFIC @ pastor @ |
Serial |
1005 |
Permanent link to this record |