| Records |
| Author |
Casas, F.; Oteo, J.A.; Ros, J. |
| Title |
Unitary transformations depending on a small parameter |
Type |
Journal Article |
| Year |
2012 |
Publication |
Proceedings of the Royal Society A |
Abbreviated Journal |
Proc. R. Soc. A |
| Volume |
468 |
Issue |
2139 |
Pages |
685-700 |
| Keywords |
perturbation theory; quantum mechanics; unitary transformation; Magnus expansion |
| Abstract |
We formulate a unitary perturbation theory for quantum mechanics inspired by the Lie-Deprit formulation of canonical transformations. The original Hamiltonian is converted into a solvable one by a transformation obtained through a Magnus expansion. This ensures unitarity at every order in a small parameter. A comparison with the standard perturbation theory is provided. We work out the scheme up to order ten with some simple examples. |
| Address |
[Oteo, J. A.; Ros, J.] Univ Valencia, Dept Fis Teor, E-46100 Valencia, Spain, Email: rosj@uv.es |
| Corporate Author |
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Thesis |
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| Publisher |
Royal Soc |
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 |
1364-5021 |
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:000300185400005 |
Approved |
no |
| Is ISI |
yes |
International Collaboration  |
no |
| Call Number |
IFIC @ pastor @ |
Serial |
893 |
| 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 |
|
| Notes |
WOS:000303785300014 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
no |
| Call Number |
IFIC @ pastor @ |
Serial |
1005 |
| 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 |
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Conference |
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| 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 |
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| 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 |
Caballero, L.; Albiol, F.; Corbi Bellot, A.; Domingo-Pardo, C.; Leganes Nieto, J.L.; Agramunt Ros, J.; Contreras, P.; Monserrate, M.; Olleros Rodriguez, P.; Perez Magan, D.L. |
| Title |
Gamma-ray imaging system for real-time measurements in nuclear waste characterisation |
Type |
Journal Article |
| Year |
2018 |
Publication |
Journal of Instrumentation |
Abbreviated Journal |
J. Instrum. |
| Volume |
13 |
Issue |
|
Pages |
P03016 - 23pp |
| Keywords |
Inspection with gamma rays; Radiation monitoring |
| Abstract |
Acompact, portable and large field-of-viewgamma camera that is able to identify, locate and quantify gamma-ray emitting radioisotopes in real-time has been developed. The device delivers spectroscopic and imaging capabilities that enable its use it in a variety of nuclear waste characterisation scenarios, such as radioactivity monitoring in nuclear power plants and more specifically for the decommissioning of nuclear facilities. The technical development of this apparatus and some examples of its application in field measurements are reported in this article. The performance of the presented gamma-camera is also benchmarked against other conventional techniques. |
| Address |
[Caballero, L.] Univ Valencia, CSIC, Inst Fis Corpuscular, C Catedrat Jose Beltran 2, E-46980 Paterna, Spain, Email: Luis.Caballero@ific.uv.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 |
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| ISSN |
1748-0221 |
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:000428146300006 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
no |
| Call Number |
IFIC @ pastor @ |
Serial |
3540 |
| Permanent link to this record |
