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Sample records for 60-130 mev photons

  1. Fissility of actinide nuclei induced by 60-130 MeV photons; Fissionabilidade de nucleos actnideos induzida por fotons de energia 60-130 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Morcelle, Viviane; Tavares, Odilon A.P

    2004-06-15

    Nuclear fissilities obtained from recent photofission reaction cross section measurements carried out at Saskatchewan Accelerator Laboratory (Saskatoon, Canada) in the energy range 60-130 MeV for {sup 232} Th, {sup 233} U, {sup 235} U, {sup 238} U, and {sup 237} Np nuclei have been analysed in a systematic way. To this aim, a semiempirical approach has been developed based on the quasi-deuteron nuclear photoabsorption model followed by the process of competition between neutron evaporation and fission for the excited nucleus. The study reproduces satisfactorily well the increasing trend of nuclear fissility with parameter Z{sup 2}=A. (author)

  2. Nuclear multifragmentation by 700–1500 MeV photons: New data of GRAAL experiment

    Energy Technology Data Exchange (ETDEWEB)

    Nedorezov, V. G., E-mail: vladimir@cpc.inr.ac.ru; Lapik, A. M. [Russian Academy of Sciences, Institute for Nuclear Research (Russian Federation); Collaboration: GRAAL Collaboration

    2015-12-15

    The cross sections of carbon nucleus photodisintegration into protons and neutrons with high multiplicity for photon energies from 700 to 1500 MeV were measured. The experiment was performed at the tagged photon beam of the GRAAL setup using the wide-aperture detector LAGRANγE. It was shown that multifragmentation up to complete disintegration into separate nucleons is initiated by elementary reactions of meson photoproduction with a subsequent intranuclear cascade.

  3. A Transformative Imaging Capability Using Laser Driven Multi MeV Photon Sources

    Science.gov (United States)

    Gautier, Donald; Espy, Michelle; Palaniyappan, Sasi; Mendez, Jacob; Nelson, Ronald; Hunter, James; Fernandez, Juan; los alamos national laboratory Team

    2016-10-01

    Recent results from the LANL Trident Laser demonstrate the practical use of a laser of this class ( 70 J, 600 fs) as a multi MeV photon source. The utilization of novel targets operating in the relativistic transparency regime of laser-plasmas has enabled this development. The electron population made from these targets, when coupled to a suitable high-Z converter foil placed near the laser target, produces an intense >1 MeV photon source with a small source size compared to conventional sources. When coupled with efficient imaging detectors, this laser-driven hard x-ray source provides new capabilities to address current non-destructive and dynamic testing problems that require a quantum jump in resolution. ``Flash'' (pulse picosecond) photon imaging, micro-focus resolution enhancement, good object penetration, and magnification (4x) with sufficient dose (>10 Rad/sr) for practical application have all been demonstrated at the LANL Trident Laser, as summarized in this presentation.

  4. Disintegration of {sup 12}C nuclei by 700–1500 MeV photons

    Energy Technology Data Exchange (ETDEWEB)

    Nedorezov, V. [Institute for Nuclear Research, Russian Academy of Sciences, Prospekt 60-letiya Oktyabrya 7a, 117312 Moscow (Russian Federation); D' Angelo, A.; Bartalini, O. [Dipartimento di Fisica – Università degli Studi di Roma “Tor Vergata”, via della Ricerca Scientifica 1, I-00133 Roma (Italy); INFN – Sezione di Roma “Tor Vergata”, via della Ricerca Scientifica 1, I-00133 Roma (Italy); Bellini, V. [Dipartimento di Fisica – Università degli Studi di Catania, via Santa Sofia 64, I-95123 Catania (Italy); INFN – Sezione di Catania, via Santa Sofia 64, I-95123 Catania (Italy); Capogni, M. [Dipartimento di Fisica – Università degli Studi di Roma “Tor Vergata”, via della Ricerca Scientifica 1, I-00133 Roma (Italy); INFN – Sezione di Roma “Tor Vergata”, via della Ricerca Scientifica 1, I-00133 Roma (Italy); Casano, L.E. [INFN – Sezione di Roma “Tor Vergata”, via della Ricerca Scientifica 1, I-00133 Roma (Italy); Castoldi, M. [Dipartimento di Fisica – Università degli Studi di Genova, via Dodecaneso 33, I-16146 Genova (Italy); Curciarello, F.; De Leo, V. [Dipartimento di Fisica e di Scienze della Terra, Università di Messina, salita Sperone 31, I-98166 Messina (Italy); INFN – Sezione di Catania, via Santa Sofia 64, I-95123 Catania (Italy); Didelez, J.-P. [IN2P3, Institut de Physique Nucléaire, Rue Georges Clemenceau, F-91406 Orsay (France); and others

    2015-08-15

    Disintegration of {sup 12}C nuclei by tagged photons of 700–1500 MeV energy at the GRAAL facility has been studied by means of the LAGRANγE detector with a wide angular acceptance. The energy and momentum distributions of produced neutrons and protons as well as their multiplicity distributions were measured and compared with corresponding distributions calculated with the RELDIS model based on the intranuclear cascade and Fermi break-up models. It was found that eight fragments are created on average once per about 100 disintegration events, while a complete fragmentation of {sup 12}C into 12 nucleons is observed typically only once per 2000 events. Measured multiplicity distributions of produced fragments are well described by the model. The measured total photoabsorption cross section on {sup 12}C in the same energy range is also reported.

  5. TARTNP: a coupled neutron--photon Monte Carlo transport code. [10-/sup 9/ to 20 MeV; in LLL FORTRAN

    Energy Technology Data Exchange (ETDEWEB)

    Plechaty, E.F.; Kimlinger, J.R.

    1976-07-04

    A Monte Carlo code was written that calculates the transport of neutrons, photons, and neutron-induced photons. The cross sections of these particles are derived from TARTNP's data base, the Evaluated Nuclear Data Library. The energy range of the neutron data in the Library is 10/sup -9/ MeV to 20 MeV; the photon energy range is 1 keV to 20 MeV. One of the chief advantages of the code is its flexibility: it allows up to 17 different kinds of output to be evaluated in the same problem.

  6. Real photon scattering up to 10 MeV: the improved facility at the Darmstadt electron accelerator S-DALINAC

    CERN Document Server

    Mohr, P J; Hartmann, T; Kaiser, H; Schiesser, D; Schmitt, S; Volz, S; Wissel, F; Zilges, A

    1999-01-01

    A new radiator and collimator system has been installed at the photon scattering facility of the superconducting electron accelerator S-DALINAC at the Darmstadt University of Technology. The new set-up allows the high-resolution (gamma,gamma') experiments to be extended to the energy range between 7 and 10 MeV without neutron induced gamma-ray background. First test measurements of sup 1 sup 1 B targets in combination with Ge(HP) detectors have been performed successfully and show the huge potential of the improved set-up.

  7. Thermoluminescent sensitivity of single clad neodymium doped SiO2 optical fibres measured with 6 MeV photons

    Science.gov (United States)

    Saeed, M. A.; Hossain, I.; Hida, N.; Wagiran, H.

    2013-10-01

    This study investigates the thermoluminescent sensitivity of neodymium doped SiO2 optical fibre with various dose ranges from 0.5 Gy to 4.0 Gy by 6 MeV photon irradiations. The TL responses of the neodymium doped silica fibres are compared with available TLD-100 dosimeter in order to determine the suitability as a TL material. We found that the TLD-100 and neodymium doped silica fibre have a significant linear signal to dose relationship. Neodymium doped fibres sensitivity is approximately 11% of TLD-100.

  8. FLUKA and PENELOPE simulations of 10 keV to 10 MeV photons in LYSO and soft tissue

    Science.gov (United States)

    Chin, M. P. W.; Böhlen, T. T.; Fassò, A.; Ferrari, A.; Ortega, P. G.; Sala, P. R.

    2014-02-01

    Monte Carlo simulations of electromagnetic particle interactions and transport by FLUKA and PENELOPE were compared. 10 keV to 10 MeV incident photon beams impinged a LYSO crystal and a soft-tissue phantom. Central-axis as well as off-axis depth doses agreed within 1 s.d.; no systematic under- or over-estimate of the pulse height spectra was observed from 100 keV to 10 MeV for both materials, agreement was within 5%. Simulation of photon and electron transport and interactions at this level of precision and reliability is of significant impact, for instance, on treatment monitoring of hadrontherapy where a code like FLUKA is needed to simulate the full suite of particles and interactions (not just electromagnetic). At the interaction-by-interaction level, apart from known differences in condensed history techniques, two-quanta positron annihilation at rest was found to differ between the two codes. PENELOPE produced a 511 keV sharp line, whereas FLUKA produced visible acolinearity, a feature recently implemented to account for the momentum of shell electrons.

  9. FLUKA and PENELOPE simulations of 10keV to 10MeV photons in LYSO and soft tissue

    CERN Document Server

    Chin, M P W; Fassò, A; Ferrari, A; Ortega, P G; Sala, P R

    2014-01-01

    Monte Carlo simulations of electromagnetic particle interactions and transport by FLUKA and PENELOPE were compared. 10 key to 10 MeV incident photon beams impinged a LYSO crystal and a soft-tissue phantom. Central-axis as well as off-axis depth doses agreed within 1 s.d.; no systematic under- or overestimate of the pulse height spectra was observed from 100 keV to 10 MeV for both materials, agreement was within 5\\%. Simulation of photon and electron transport and interactions at this level of precision and reliability is of significant impact, for instance, on treatment monitoring of hadrontherapy where a code like FLUKA is needed to simulate the full suite of particles and interactions (not just electromagnetic). At the interaction-by-interaction level, apart from known differences in condensed history techniques, two-quanta positron annihilation at rest was found to differ between the two codes. PENELOPE produced a 511 key sharp line, whereas FLUKA produced visible acolinearity, a feature recently implemen...

  10. Electron and photon beams from a 50 MeV racetrack microtron.

    Science.gov (United States)

    Brahme, A; Kraepelien, T; Svensson, H

    1980-01-01

    The quality of broad high energy photon and electron beams can be improved considerably by the scanning of elementary narrow beams. Dose distributions produced in this way have advantages with respect to improved dose gradients and therapeutic ranges for electrons and lower surface doses, increased depth doses and half value depths for photons. The possibility of giving the whole therapeutic dose in a single local pulse of short duration is discussed as a new method to protect superficial tissues.

  11. MeV- and Sub-MeV-photon Sources Based on Compton Backscattering at Spring-8 and KPSI-JAEA

    Institute of Scientific and Technical Information of China (English)

    K.Kawase; M.Kando; T.Hayakawa; I.Daito; S.Kondo; T.Homma; T.Kameshima; H.Kotaki; L.Chen; Y.Fukuda; A.Faenov; Shizuma; S.V.Bulanov; T.Kimura; T.Tajima; M.Shoji; S.Suzuki; K.Tamura; H.Ohkuma; Y.Arimoto; T.Yorita; M.Fujiwara; S.Okajima

    2009-01-01

    Recently we have constructed two facilities for generating photon beams in the MeV and sub-MeV energy regions by means of the Compton backscattering with a laser and an electron beam at SPring-8 and at Kansai Photon Science Institute of Japan Atomic Energy Agency(KPSIJAEA).The MeV-photon source at SPring-8 consists of a continuous-wave optically-pumped far infrared laser with a wavelength of 118.8 μm and an 8 GeV stored electron beam.Present MeV-photon flux is estimated to be 1.3×10~3 photons/s.On the other hand,the sub-MeV-photon source at KPSI-JAEA consists of a pulse Nd:YAG laser with a wavelength of 1 064 nm and a 150 MeV electron beam accelerated by microtron.In the first trial of the photon production in this source,backscattered photon flux is estimated to be 20 photons/pulse.Both the Compton backscattered photon sources have possibilities to be used for new tools in various fields such as nuclear physics,materials science,and astronomy.

  12. Response of BGO detectors to photons of 3-50 MeV energy

    Science.gov (United States)

    Matulewicz, T.; Henning, W.; Emling, H.; Freifelder, R.; Grein, H.; Grosse, E.; Herrmann, N.; Holzmann, R.; Kulessa, R.; Simon, R. S.; Wollersheim, H. J.; Schoch, B.; Vogt, J.; Wilhelm, M.; Kratz, J. V.; Schmidt, R.; Janssens, R. V. F.

    1993-02-01

    The response of an array of 7 hexagonal BGO detectors each 7.5 cm long (6.7 radiation lengths) with 3.6 cm side-to-side distance was measured using monochromatic photons from the tagged-photon facility at the electron accelerator MAMI A at Mainz. The experimental spectra of the deposited energy for a single detector and for the array of seven modules compare very well with the predictions of Monte Carlo shower simulations using the code GEANT3. Significant improvement of the energy resolution is observed for the summed energy spectra compared to the resolution of a single module. This improvement deteriorates at higher photon energies because the length of the detector is not sufficient to absorb the forward component of the electromagnetic shower.

  13. Response of BGO detectors to photons of 3-50 MeV energy

    Energy Technology Data Exchange (ETDEWEB)

    Matulewicz, T.; Henning, W.; Emling, H.; Freifelder, R.; Grein, H.; Grosse, E.; Herrmann, N.; Holzmann, R.; Kulessa, R.; Simon, R.S.; Wollersheim, H.J. (Gesellschaft fuer Schwerionenforschung, Darmstadt (Germany)); Schoch, B.; Vogt, J.; Wilhelm, M. (Inst. fuer Kernphysik, Univ. Mainz (Germany)); Kratz, J.V.; Schmidt, R. (Inst. fuer Kernchemie, Univ. Mainz (Germany)); Janssens, R.V.F. (Argonne National Lab., IL (United States))

    1993-02-01

    The response of an array of 7 hexagonal BGO detectors each 7.5 cm long (6.7 radiation lengths) with 3.6 cm side-to-side distance was measured using monochromatic photons from the tagged-photon facility at the electron accelerator MAMI A at Mainz. The experimental spectra of the deposited energy for a single detector and for the array of seven modules compare very well with the predictions of Monte Carlo shower simulations using the code GEANT3. Significant improvement of the energy resolution is observed for the summed energy spectra compared to the resolution of a single module. This improvement deteriorates at higher photon energies because the length of the detector is not sufficient to absorb the forward component of the electromagnetic shower. (orig.).

  14. Demonstration of multilayer reflective optics at photon energies above 0.6 MeV

    DEFF Research Database (Denmark)

    Brejnholt, Nicolai F.; Soufli, Regina; Descalle, Marie-Anne;

    2014-01-01

    Focusing optics operating in the soft gamma-ray photon energy range can advance a range of scientific and technological applications that benefit from the large improvements in sensitivity and resolution that true imaging provides. An enabling technology to this end is multilayer coatings. We show...

  15. Material Classification by Analysis of Prompt Photon Spectra Induced by 14-Mev Neutrons

    Science.gov (United States)

    Barzilov, Alexander; Novikov, Ivan

    Neutron based technologies are widely used in the field of bulk material analysis. These methods employ characteristic prompt gamma rays induced by a neutron probe for classification of the interrogated object using the elemental parameters extracted from the spectral data. Automatic data analysis and material classification algorithms are required for applications where access to nuclear spectroscopy expertise is limited and/or the autonomous robotic operation is necessary. Data obtained with neutron based systems differ from elemental composition evaluations based on chemical formulae due to statistical nature of nuclear reactions, presence of shielding and cladding, and other environmental conditions. Experimental data that are produced by the spectral decomposition can be expressed graphically as sets of overlapping classes in a multidimensional space of measured elemental intensities. To discriminate between classes of various materials, decision-tree and pattern recognition algorithms were studied. Results of application of these methods to data sets obtained for a pulsed 14-MeV neutron generator based active interrogation system are discussed.

  16. Photofission cross section and fissility of pre-actinide and intermediate-mass nuclei by 120- and 145-MeV Compton backscattered photons

    Energy Technology Data Exchange (ETDEWEB)

    Terranova, M.L. [Istituto Nazionale di Fisica Nucleare, Rome (Italy); Kezerashvili, G. Ya.; Milov, A.M. [Russian Academy of Sciences, Moscow (Russian Federation). Budker Inst. of Nuclear Physics] [and others

    1997-09-01

    Cross section measurements for photofission induced in {sup 209} Bi, {sup natP}b, {sup 197} Au, {sup nat} Pt, nat{sub w}, {sup 181} Ta, {sup 51} V and {sup nat} Ti by 120- and 145-MeV quasi-monochromatic photon beams have been performed at the ROKK-1M facility (BINP, Novosibirsk). The fission yields have been obtained using Makrofol sheets as solid-state fission track detectors. Nuclear fissility values have been deduced on the basis of Levinger`s modified quasi-deuteron model of photonuclear interaction, and compared with available literature data. The trend of fissility in the 60-145 MeV energy range has been analysed for various target nuclei as function of energy and of parameter Z{sup 2}/A. (author) 30 refs., 6 figs., 4 tabs.

  17. Energy dependence of effective atomic numbers for photon energy absorption and photon interaction: Studies of some biological molecules in the energy range 1 keV-20 MeV

    DEFF Research Database (Denmark)

    Manohara, S.R.; Hanagodimath, S.M.; Gerward, Leif

    2008-01-01

    Effective atomic numbers for photon energy absorption, Z(PEA,eff), and for photon interaction, Z(PI,eff), have been calculated by a direct method in the photon-energy region from 1 keV to 20 MeV for biological molecules, such as fatty acids (lauric, myristic, palmitic, stearic, oleic, linoleic...... dependence of the mass attenuation coefficient, Z(PEA, eff), and the mass energy-absorption coefficient, Z(PI, eff), is shown graphically and in tabular form. Significant differences of 17%-38% between Z(PI, eff) and Z(PEA, eff) occur in the energy region 5-100 keV. The reasons for these differences...

  18. Photon activation analysis of the scraper in a 200-MeV electron accelerator using gamma-spectrometry depth profiling

    CERN Document Server

    Lijuan, He; Guobing, Yu; Guangyi, Ren; Zongjin, Duan

    2014-01-01

    For a high energy electron facility, the estimates of induced radioactivity in materials are of major importance to keep exposure to personnel and to the environment as low as reasonably achievable. In addition, an accurate prediction of induced radioactivity is also essential for the design, operation and decommissioning of a high energy electron linear accelerator. The research of induced radioactivity focuses on the photonuclear reaction, whose giant resonance response in the copper is ranging from 10 MeV to 28 MeV. The 200 MeV electron linac of NSRL is one of the earliest high-energy electron linear accelerators in P. R. China. The electrons are accelerated to 200 MeV by five acceleration tubes and collimated by the scrapers made of copper. At present, it is the first retired high-energy electron linear accelerator in domestic. Its decommissioning provides an efficient way for the induced radioactivity research of such accelerators, and is a matter of great significance to the accumulation of the induced ...

  19. Response of BaF 2 detectors to photons of 3-50 MeV energy

    Science.gov (United States)

    Matulewicz, T.; Grosse, E.; Emling, H.; Freifelder, R.; Grein, H.; Henning, W.; Herrmann, N.; Holzmann, R.; Kulessa, R.; Simon, R. S.; Wollersheim, H. J.; Schoch, B.; Vogt, J.; Wilhelm, M.; Kratz, J. V.; Schmidt, R.; Janssens, R. V. F.

    1990-04-01

    BaF 2 detectors of 20 cm length (10 radiation lengths) and hexagonal cross section (diameter 5.2 cm) were tested using monochromatic photons from the tagged-photon facility at the electron accelerator MAMIA at Mainz. The experimental spectra the deposited energy for a single detector and for an array of seven modules compare very well with the predictions of Monte Carlo shower simulations using the code GEANT3. At high photon energies a significant improvement (more than a factor 2) of the energy resolution is observed for the summed energy spectra as compared to the resolution of one single module.

  20. Response of BaF sub 2 detectors to photons of 3-50 MeV energy

    Energy Technology Data Exchange (ETDEWEB)

    Matulewicz, T.; Grosse, E.; Emling, H.; Freifelder, R.; Grein, H.; Henning, W.; Herrmann, N.; Holzmann, R.; Kulessa, R.; Simon, R.S.; Wollersheim, H.J. (Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany, F.R.)); Schoch, B.; Vogt, J.; Wilhelm, M. (Mainz Univ. (Germany, F.R.). Inst. fuer Kernphysik); Kratz, J.V.; Schmidt, R. (Mainz Univ. (Germany, F.R.). Inst. fuer Kernchemie); Janssens, R.V.F. (Ar

    1990-01-01

    BaF{sub 2} detectors of 20 cm length (10 radiation lengths) and hexagonal cross section (diameter 5.2 cm) were tested using monochromatic photons from the tagged-photon facility at the electron accelerator MAMI A at Mainz. The experimental spectra of the deposited energy for a single detector and for an array of seven modules compare very well with the predictions of Monte Carlo shower simulations using the code GEANT3. At high photon energies a significant improvement (more than a factor 2) of the energy resolution is observed for the summed energy spectra as compared to the resolution of one single module. (orig.).

  1. Response of BaF sub 2 detectors to photons of 3-50 MeV energy

    Energy Technology Data Exchange (ETDEWEB)

    Matulewicz, T.; Grosse, E.; Emling, H.; Freifelder, R.; Grein, H.; Henning, W.; Herrmann, N.; Holzmann, R.; Kulessa, R.; Simon, R.S.; Wollersheim, H.J. (Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany, F.R.)); Schoch, B.; Vogt, J.; Wilhelm, M. (Mainz Univ. (Germany, F.R.). Inst. fuer Kernphysik); Kratz, J.V.; Schmidt, R. (Mainz Univ. (Germany, F.R.). Inst. fuer Kernchemie); Janssens, R.V.F. (Argonne National Lab., IL (USA))

    1990-04-01

    BaF{sub 2} detectors of 20 cm length (10 radiation lengths) and hexagonal cross section (diameter 5.2 cm) were tested using monochromatic photons from the tagged-photon facility at the electron accelerator MAMIA at Mainz. The experimental spectra of the deposited energy for a single detector and for an array of seven modules compare very well with the predictions of Monte Carlo shower simulations using the code GEANT3. At high photon energies a significant improvement (more than a factor 2) of the energy resolutions is observed for the summed energy spectra as compared to the resolution of one single module. (orig.).

  2. A compact BaF sub 2 array for high energy (< or approx. 50 MeV) photons

    Energy Technology Data Exchange (ETDEWEB)

    Kernan, W.J.; Gan, N.; Caraley, A.L.; Fineman, B.J.; McGrath, R.L.; Vojtech, R.J. (Dept. of Physics, State Univ. of New York, Stony Brook, NY (United States))

    1992-03-15

    A compact array of seven BaF{sub 2} detectors with active plastic shielding has been developed for the measurement of hard photons in the presence of fast neutrons and cosmic ray muon background. (orig.).

  3. Response of TLD badge to mixed fields of photons of energies above 6 MeV and beta radiation encountered in nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Pradhan, A.S.; Bakshi, A.K. [Bhabha Atomic Research Centre, Trombay, Mumbai (India)

    2000-05-01

    Response of TLD badge in use for our countrywide personnel monitoring was evaluated for high-energy photon beams (10 MV, 15 MV and 18 MV) from medical Linear Accelerators with beam output measurements within an accuracy better than {+-}3%. The badge has three CaSO{sub 4}:Dy teflon TLD discs (each of dia. 13.5 mm and thickness 0.8 mm) clipped on an aluminum card kept in a cassette having three regions (i) combined metal filter of 1 mm thick Cu and 1 mm thick Al, (ii) 1.6 mm thick plastic filter and (iii) an open window area on either side sandwiching the TLD card. Mainly discs under metal filter and open window are used to estimate the dose due to gamma rays and beta rays, respectively while ratios of responses of discs under plastic filter and open window/metal filter in an algorithm are used for arriving at the correction factors for evaluation of beta and gamma ray doses. In nuclear power plants, especially the CANDU pressurized heavy water reactor systems, gamma ray of energy higher than 6 MeV (produced from disintegration of {sup 16}N via the reaction {sup 16}O(n p){sup 16}N) do contribute significantly to personal dose equivalent Hp(10) in addition to situations where beta radiation contributes to personal dose equivalent Hp(0.07). The values of absorbed doses at 10 mm in phantom were obtained from the measured values of dose at Dmax traceable to national standard and irradiations of dosimeters were made on a plastic phantom of size 25x25x25 cm{sup 3}. The bare dosimeter disc was found to exhibit no photon energy dependence for high energy photons of energy above 300 keV (up to 7 MeV). However, the response of the badge was found to increase by about 10% above 6 MeV as compared to that of Co-60 gamma rays due to the influence of metal filters used in the badge for compensation of photon energy (below 200keV) response. In the case of LiF TLD-100 ribbons sandwiched between 0.3 mm thick Cu filters, no over-response was observed. A significant complication in the

  4. Photon asymmetry measurements of $\\overrightarrow{\\gamma} \\mathrm{p} \\rightarrow \\pi^{0} \\mathrm{p}$ for E$_{\\gamma}$=320$-$650 MeV

    CERN Document Server

    Gardner, S; Sikora, M H; Wunderlich, Y; Abt, S; Achenbach, P; Afzal, F; Aguar-Bartolome, P; Ahmed, Z; Annand, J R M; Arends, H J; Bantawa, K; Bashkanov, M; Beck, R; Biroth, M; Borisov, N S; Braghieri, A; Briscoe, W J; Cherepnya, S; Cividini, F; Costanza, S; Collicott, C; Demissie, B T; Denig, A; Dieterle, M; Downie, E J; Drexler, P; Ferretti-Bondy, M I; Filkov, L V; Glazier, D I; Garni, S; Gradl, W; Günther, M; Gurevich, G M; Hamilton, D; Heid, E; Hornidge, D; Huber, G M; Jahn, O; Jude, T C; Käser, A; Kay, S; Kashevarov, V L; Keshelashvili, I; Kondratiev, R; Korolija, M; Krusche, B; Linturi, J M; Lisin, V; Livingston, K; Lutterer, S; MacGregor, I J D; Macrae, R; Mancell, J; Manley, D M; Martel, P P; McGeorge, J C; McNicoll, E F; Middleton, D G; Miskimen, R; Mullen, C; Mushkarenkov, A; Neganov, A B; Neiser, A; Nikolaev, A; Oberle, M; Ostrick, M; Owens, R O; Otte, P B; Oussena, B; Paudyal, D; Pedroni, P; Polonski, A; Prakhov, S; Rajabi, A; Robinson, J; Rosner, G; Rostomyan, T; Sarty, A; Schumann, S; Sokhoyan, V; Spieker, K; Steffen, O; Sfienti, C; Strakovsky, I I; Strandberg, B; Strub, Th; Supek, I; Tarbert, C M; Thiel, A; Thiel, M; Thomas, A; Unverzagt, M; Usov, Yu A; Watts, D P; Werthmüller, D; Wettig, J; Wolfes, M; Witthauer, L; Zana, L

    2016-01-01

    High statistics measurements of the photon asymmetry $\\mathrm{\\Sigma}$ for the $\\overrightarrow{\\gamma}$p$\\rightarrow\\pi^{0}$p reaction have been made in the center of mass energy range W=1214-1450 MeV. The data were measured with the MAMI A2 real photon beam and Crystal Ball/TAPS detector systems in Mainz, Germany. The results significantly improve the existing world data and are shown to be in good agreement with previous measurements, and with the MAID, SAID, and Bonn-Gatchina predictions. We have also combined the photon asymmetry results with recent cross-section measurements from Mainz to calculate the profile functions, $\\check{\\mathrm{\\Sigma}}$ (= $\\sigma_{0}\\mathrm{\\Sigma}$), and perform a moment analysis. Comparison with calculations from the Bonn-Gatchina model shows that the precision of the data is good enough to further constrain the higher partial waves, and there is an indication of interference between the very small $F$-waves and the $N(1520) 3/2^{-}$ and $N(1535) 1/2^{-}$ resonances.

  5. Photonics

    CERN Document Server

    Andrews, David L

    2015-01-01

    This book covers modern photonics accessibly and discusses the basic physical principles underlying all the applications and technology of photonicsThis volume covers the basic physical principles underlying the technology and all applications of photonics from statistical optics to quantum optics. The topics discussed in this volume are: Photons in perspective; Coherence and Statistical Optics; Complex Light and Singular Optics; Electrodynamics of Dielectric Media; Fast and slow Light; Holography; Multiphoton Processes; Optical Angular Momentum; Optical Forces, Trapping and Manipulation; Pol

  6. Photonics

    CERN Document Server

    Andrews, David L

    2015-01-01

    Discusses the basic physical principles underlying Biomedical Photonics, spectroscopy and microscopy This volume discusses biomedical photonics, spectroscopy and microscopy, the basic physical principles underlying the technology and its applications. The topics discussed in this volume are: Biophotonics; Fluorescence and Phosphorescence; Medical Photonics; Microscopy; Nonlinear Optics; Ophthalmic Technology; Optical Tomography; Optofluidics; Photodynamic Therapy; Image Processing; Imaging Systems; Sensors; Single Molecule Detection; Futurology in Photonics. Comprehensive and accessible cov

  7. Photonics

    CERN Document Server

    Andrews, David L

    2015-01-01

    Discusses the basic physical principles underlying the technology instrumentation of photonics This volume discusses photonics technology and instrumentation. The topics discussed in this volume are: Communication Networks; Data Buffers; Defense and Security Applications; Detectors; Fiber Optics and Amplifiers; Green Photonics; Instrumentation and Metrology; Interferometers; Light-Harvesting Materials; Logic Devices; Optical Communications; Remote Sensing; Solar Energy; Solid-State Lighting; Wavelength Conversion Comprehensive and accessible coverage of the whole of modern photonics Emphas

  8. Photonics

    CERN Document Server

    Andrews, David L

    2015-01-01

    Discusses the basic physical principles underlying thescience and technology of nanophotonics, its materials andstructures This volume presents nanophotonic structures and Materials.Nanophotonics is photonic science and technology that utilizeslight/matter interactions on the nanoscale where researchers arediscovering new phenomena and developing techniques that go wellbeyond what is possible with conventional photonics andelectronics.The topics discussed in this volume are: CavityPhotonics; Cold Atoms and Bose-Einstein Condensates; Displays;E-paper; Graphene; Integrated Photonics; Liquid Cry

  9. Tables and graphs of photon-interaction cross sections from 0. 1 keV to 100 MeV derived from the LLL evaluated-nuclear-data library

    Energy Technology Data Exchange (ETDEWEB)

    Plechaty, E.F.; Cullen, D.E.; Howerton, R.J.

    1981-11-11

    Energy-dependent evaluated photon interaction cross sections and related parameters are presented for elements H through Cf(Z = 1 to 98). Data are given over the energy range from 0.1 keV to 100 MeV. The related parameters include form factors and average energy deposits per collision (with and without fluorescence). Fluorescence information is given for all atomic shells that can emit a photon with a kinetic energy of 0.1 keV or more. In addition, the following macroscopic properties are given: total mean free path and energy deposit per centimeter. This information is derived from the Livermore Evaluated-Nuclear-Data Library (ENDL) as of October 1978.

  10. Tests of a Compton imaging prototype in a monoenergetic 4.44 MeV photon field—a benchmark setup for prompt gamma-ray imaging devices

    Science.gov (United States)

    Golnik, C.; Bemmerer, D.; Enghardt, W.; Fiedler, F.; Hueso-González, F.; Pausch, G.; Römer, K.; Rohling, H.; Schöne, S.; Wagner, L.; Kormoll, T.

    2016-06-01

    The finite range of a proton beam in tissue opens new vistas for the delivery of a highly conformal dose distribution in radiotherapy. However, the actual particle range, and therefore the accurate dose deposition, is sensitive to the tissue composition in the proton path. Range uncertainties, resulting from limited knowledge of this tissue composition or positioning errors, are accounted for in the form of safety margins. Thus, the unverified particle range constrains the principle benefit of proton therapy. Detecting prompt γ-rays, a side product of proton-tissue interaction, aims at an on-line and non-invasive monitoring of the particle range, and therefore towards exploiting the potential of proton therapy. Compton imaging of the spatial prompt γ-ray emission is a promising measurement approach. Prompt γ-rays exhibit emission energies of several MeV. Hence, common radioactive sources cannot provide the energy range a prompt γ-ray imaging device must be designed for. In this work a benchmark measurement-setup for the production of a localized, monoenergetic 4.44 MeV γ-ray source is introduced. At the Tandetron accelerator at the HZDR, the proton-capture resonance reaction 15N(p,α γ4.439)12C is utilized. This reaction provides the same nuclear de-excitation (and γ-ray emission) occurrent as an intense prompt γ-ray line in proton therapy. The emission yield is quantitatively described. A two-stage Compton imaging device, dedicated for prompt γ-ray imaging, is tested at the setup exemplarily. Besides successful imaging tests, the detection efficiency of the prototype at 4.44 MeV is derived from the measured data. Combining this efficiency with the emission yield for prompt γ-rays, the number of valid Compton events, induced by γ-rays in the energy region around 4.44 MeV, is estimated for the prototype being implemented in a therapeutic treatment scenario. As a consequence, the detection efficiency turns out to be a key parameter for prompt

  11. Study of radionuclides created by sup 181 Ta(. gamma. ,xn yp) reactions for bremsstrahlung photons produced by 150-MeV electrons

    Energy Technology Data Exchange (ETDEWEB)

    Miller, M.A. (Wisconsin Univ., River Falls, WI (United States)); Dickens, J.K. (Oak Ridge National Lab., TN (United States))

    1991-12-01

    Ten radionuclides, including isomers, from {sup 172}Ta to {sup 180}Ta and {sup 180m}Hf were produced by photon interactions with a sample of elemental tantalum and measured by counting photons using a high-resolution detection system. Relative yields of these radionuclides were obtained. In addition, precision half lives were obtained for {sup 175,176,180}Ta and {sup 180m}Hf. Those obtained for the three Ta isotopes agree with previously reported values. For {sup 180m}Hf, the present measurements resulted in a half life determination of 6.05{plus minus}0.06 hr, or about 10% longer than the currently adopted value for this half life.

  12. Study of radionuclides created by {sup 181}Ta({gamma},xn yp) reactions for bremsstrahlung photons produced by 150-MeV electrons

    Energy Technology Data Exchange (ETDEWEB)

    Miller, M.A. [Wisconsin Univ., River Falls, WI (United States); Dickens, J.K. [Oak Ridge National Lab., TN (United States)

    1991-12-01

    Ten radionuclides, including isomers, from {sup 172}Ta to {sup 180}Ta and {sup 180m}Hf were produced by photon interactions with a sample of elemental tantalum and measured by counting photons using a high-resolution detection system. Relative yields of these radionuclides were obtained. In addition, precision half lives were obtained for {sup 175,176,180}Ta and {sup 180m}Hf. Those obtained for the three Ta isotopes agree with previously reported values. For {sup 180m}Hf, the present measurements resulted in a half life determination of 6.05{plus_minus}0.06 hr, or about 10% longer than the currently adopted value for this half life.

  13. Air kerma to HP(3) conversion coefficients for photons from 10 keV to 10 MeV, calculated in a cylindrical phantom.

    Science.gov (United States)

    Gualdrini, G; Bordy, J M; Daures, J; Fantuzzi, E; Ferrari, P; Mariotti, F; Vanhavere, F

    2013-05-01

    In the framework of the ORAMED project (Optimization of RAdiation protection for MEDical staff), funded by the European Union Seventh Framework Programme, different studies were aimed at improving the quality of radiation protection in interventional radiology and nuclear medicine. The main results of the project were presented during a final workshop held in Barcelona in January 2011, the proceedings of which are available in the open literature. One of the ORAMED tasks was focused on the problem of eye-lens photon exposure of the medical staff, a topic that gained more importance especially after the ICRP decision to lower the limiting equivalent dose to 20 mSv per year. The present technical note has the scope, besides briefly summarising the physical reasons of the proposal and the practical implications, to provide, in tabular form, a set of air kerma to Hp(3) conversion coefficients based on the adoption of a theoretical cylindrical model that is well suited for reproduction of the mass and the shape of a human head.

  14. Characterization of 2 MeV, 4 MeV, 6 MeV and 18 MeV buildup caps for use with a 0.6 cubic centimeter thimble ionization chamber

    Energy Technology Data Exchange (ETDEWEB)

    Salyer, R.L.; VanDenburg, J.W.; Prinja, A.K.; Kirby, T.; Busch, R. [Univ. of New Mexico, Albuquerque, NM (United States); Hong-Nian Jow [Sandia National Laboratories, Albuquerque, NM (United States)

    1996-07-01

    The purpose of this research is to characterize existing 2 MeV, 4 MeV and 6 MeV buildup caps, and to determine if a buildup cap can be made for the 0.6 cm{sup 3} thimble ionization chamber that will accurately measure exposures in a high-energy photon radiation field. Two different radiation transport codes were used to computationally characterize existing 2 MeV, 4 MeV, and 6 MeV buildup caps for a 0.6 cm{sup 3} active volume thimble ionization chamber: ITS, The Integrated TIGER Series of Coupled Electron-Photon Monte Carlo Transport Codes; and CEPXS/ONEDANT, A One-Dimensional Coupled Electron-Photon Discrete Ordinates Code Package. These codes were also used to determine the design characteristics of a buildup cap for use in the 18 MeV photon beam produced by the 14 TW pulsed power HERMES-III electron accelerator. The maximum range of the secondary electron, the depth at which maximum dose occurs, and the point where dose and collision kerma are equal have been determined to establish the validity of electronic equilibrium. The ionization chamber with the appropriate buildup cap was then subjected to a 4 MeV and a 6 MeV bremmstrahlung radiation spectrum to determine the detector response.

  15. Two body photodisintegration of the deuteron from 100 to 800 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, R.; Annand, J.R.M.; Anthony, I. [Glasgow Univ. (United Kingdom). Dept. of Physics and Astronomy; Ahrens, J.; Beck, R. [Mainz Univ. (Germany). Inst. fuer Kernphysik; Braghieri, A.; Pedroni, P. [Istituto Nazionale di Fisica Nucleare, Pavia (Italy); Altieri, S. [Istituto Nazionale di Fisica Nucleare, Pavia (Italy)]|[Pavia Univ. (Italy). Ist. di Fisica Nucleare; Audit, G.; D`Hose, N. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. d`Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l`Instrumentation Associee] [and others

    1996-01-01

    The total and the differential cross sections for the D({gamma},p)n reaction have been measured over the photon energy range 100-800 MeV at the 855 MeV MAMI Microtron in Mainz. The data are presented in the form of thirty-five angular distributions at c.m. proton angles between 30 deg-160 deg in 10 deg intervals and at photon energies in steps of 20 MeV. Previous experimental work is reassessed in the light of the present results and the results compared with some recent theoretical calculations. (author). Submitted to Nuclear Physics, B (NL); 23 refs.

  16. ANALYSIS OF THE EFFICIENCY OF A THERAPEUTIC PROGRAM USING 10.2-MEV FAST NEUTRONS. OPTIMIZATION AND PROSPECTS OF THE DEVELOPMENT OF A PROCEDURE FOR COMBINED PHOTON-NEUTRON THERAPY. THE EXPERIENCE OF THE URAL CENTER FOR NEUTRON THERAPY

    Directory of Open Access Journals (Sweden)

    E. Yu. Kandakova

    2013-01-01

    Full Text Available The Ural Center for Neutron Therapy performs combined photon-neutron therapy for cancer patients, by applying an ELLIT-80 gamma unit and a NG-12I neutron generator. After modernization of the NG-12I generator, there was a need for redetermination of the relative biological efficiency (RBE to optimize radiotherapy for the patients. An exotest was used to experimentally estimate RBE according to the survival criteria for stem hematopoietic cells in CBA mice after modernization of the equipment generated by the NG-12I unit with respect to the gamma radiation generated by the ELLIT-80 unit. The investigation established that the RBE factor of NG-12I unit-induced radiation determined as the ratio of equally effective doses (our study used D0 was 1.53 for an acute radiation regimen. During fractional radiation, the RBE factor of neutron radiation was 3.05. That is to say, the total neutron radiation dose replacing 20 % gamma radiation (13 Gy in the used photon-neutron therapy regimen is 4.26 Gy. The experimental findings have led us to conclude that the previously described neuron therapy regimen may be optimized, by increasing the contribution of neutrons to the total course of radiotherapy in a definite category of patients with radioresistant tumors of the head and neck.

  17. Calculating Rayleigh scattering amplitudes from 100 eV to 10 MeV. [100 eV to 10 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Parker, J.C.; Reynaud, G.W.; Botto, D.J.; Pratt, R.H.

    1979-05-01

    An attempt is made to explain how to calculate the contribution to elastic photon-atom scattering due to Rayleigh scattering (the scattering off bound electrons) in the photon energy range 100 eV less than or equal to W less than or equal to 10 MeV. All intermediate calculations are described, including the calculation of the potential, bound state wave functions, matrix elements, and final cross sections. 12 references. (JFP)

  18. Soft photon registration at Nuclotron

    CERN Document Server

    Kokoulina, Elena; Golovkin, V; Golovnya, S; Gorokhov, S; Kholodenko, A; Kiryakov, A; Lobanov, I; Polkovnikov, M; Ronzhin, V; Ryadovikov, V; Tsyupa, Yu; Vorobiev, A; Avdeichikov, V; Balandin, V; Dunin, V; Gavrishchuk, O; Isupov, A; Kuzmin, N; Nikitin, V; Petukhov, Yu; Reznikov, S; Rogov, V; Rufanov, I; Zhidkov, N; Zolin, L; Bogdanova, G; Popov, V; Volkov, V; Kutov, A; Kazakov, A; Pokatashkin, G; Salyanko, R

    2015-01-01

    First results of a soft photon yield in nucleus-nuclear interactions at 3.5 GeV per nucleon are presented. These photons have been registered at Nuclotron (LHEP, JINR) by an electromagnetic calorimeter built in the SVD Collaboration. The obtained spectra confirm the excess yield in the energy region less than 50 MeV in comparison with theoretical predictions and agree with previous experiments at high-energy interactions.

  19. EMISSION OF PHOTONS IN SPONTANEOUS FISSION OF CF-252

    NARCIS (Netherlands)

    VANDERPLOEG, H; BACELAR, JCS; BUDA, A; LAURENS, CR; VANDERWOUDE, A; GAARDHOJE, JJ; ZELAZNY, Z; VANTHOF, G; KALANTARNAYESTANAKI, N

    1995-01-01

    High energy photon emission accompanying the spontaneous fission of Cf-252 is measured for different mass splits. The photon yields up to an energy of 20 MeV are obtained at several angles relative to the fission direction. Statistical model calculations are used to interpret the data. The photon yi

  20. Phenomenological Study of 3He Photodisintegration up to 150 MeV

    Institute of Scientific and Technical Information of China (English)

    WANG Cheng-Bin; ZHU Zhi-Yuan

    2008-01-01

    @@ A parametrization of 3He(γ,p)2H cross section data at laboratory photon energies between 9 and 150MeV is carried out with a simple phenomenological function. The differential cross section data are normalized to the total cross-section values, which are consistent with the measurement from monochromatic photon beams. The obtained results give a good representation of the experimental points.

  1. Photon-photon collisions

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, S.J.

    1988-07-01

    Highlights of the VIIIth International Workshop on Photon-Photon Collisions are reviewed. New experimental and theoretical results were reported in virtually every area of ..gamma gamma.. physics, particularly in exotic resonance production and tests of quantum chromodynamics where asymptotic freedom and factorization theorems provide predictions for both inclusive and exclusive ..gamma gamma.. reactions at high momentum transfer. 73 refs., 12 figs.

  2. Photonuclear reaction based high-energy x-ray spectrometer to cover from 2 MeV to 20 MeV.

    Science.gov (United States)

    Sakata, S; Arikawa, Y; Kojima, S; Ikenouchi, T; Nagai, T; Abe, Y; Inoue, H; Morace, A; Utsugi, M; Kato, R; Nishimura, H; Nakai, M; Shiraga, H; Fujioka, S; Azechi, H

    2014-11-01

    A photonuclear-reaction-based hard x-ray spectrometer is developed to measure the number and energy spectrum of fast electrons generated by interactions between plasma and intense laser light. In this spectrometer, x-rays are converted to neutrons through photonuclear reactions, and the neutrons are counted with a bubble detector that is insensitive to x-rays. The spectrometer consists of a bundle of hard x-ray detectors that respond to different photon-energy ranges. Proof-of-principle experiment was performed on a linear accelerator facility. A quasi-monoenergetic electron bunch (Ne = 1.0 × 10(-6) C, Ee = 16 ± 0.32 MeV) was injected into a 5-mm-thick lead plate. Bremsstrahlung x-rays, which emanate from the lead plate, were measured with the spectrometer. The measured spectral shape and intensity agree fairly well with those computed with a Monte Carlo simulation code. The result shows that high-energy x-rays can be measured absolutely with a photon-counting accuracy of 50%-70% in the energy range from 2 MeV to 20 MeV with a spectral resolution (Δhν/hν) of about 15%. Quantum efficiency of this spectrometer was designed to be 10(-7), 10(-4), 10(-5), respectively, for 2-10, 11-15, and 15-25 MeV of photon energy ranges.

  3. Induced photonuclear interaction by Rhodotron-TT200 10 MeV electron beam

    Indian Academy of Sciences (India)

    Farshid Tabbakh; Mojtaba Mostajab Aldaavati; Mahdieh Hoseyni; Khadijeh Rezaee Ebrahim Saraee

    2012-02-01

    In this paper the photonuclear interaction induced by 10 MeV electron beam generating high-intensity neutrons is studied. Since the results depend on the target material, the calculations are performed for Pb, Ta and W targets which have high , in a simple geometry. MCNPX code has been used to simulate the whole process. Also, the results of photon generation has been compared with the experimental results to evaluate the reliability of the calculation. The results show that the obtained neutron flux can reach up to 1012 n/cm2 /s with average energies of 0.9 MeV, 0.4 MeV and 0.9 MeV for these three elements respectively with the maximum heat deposited as 3000 W/c3,4500 W/c3 and 6000 W/c3.

  4. Hard photons in heavy-ion collisions: Direct or statistical\\?

    Science.gov (United States)

    Herrmann, N.; Bock, R.; Emling, H.; Freifelder, R.; Gobbi, A.; Grosse, E.; Hildenbrand, K. D.; Kulessa, R.; Matulewicz, T.; Rami, F.; Simon, R. S.; Stelzer, H.; Wessels, J.; Maurenzig, P. R.; Olmi, A.; Stefanini, A. A.; Kühn, W.; Metag, V.; Novotny, R.; Gnirs, M.; Pelte, D.; Braun-Munzinger, P.; Moretto, L. G.

    1988-04-01

    Photons with energies from 2 to 60 MeV have been measured in coincidence with binary fragments in the reaction 92Mo+92Mo at an incident energy of 19.5A MeV. The rapid change of the γ-ray spectrum and multiplicity with the fragment total kinetic energy in the exit channel indicates that the γ rays are emitted statistically by the highly excited fragments. Temperatures as high as 6 MeV are inferred.

  5. Decay of photon with high as well as low energy

    CERN Document Server

    Bhattacharyya, Indranath

    2016-01-01

    The decay of photon by the influence of magnetic field is considered. It is shown here that if the photon energy is grater than 1 MeV then photon can decay electron positron pair, but if it remains below 1 MeV then photon decays into neutrino antineutrino pair. The decay rates for both of the processes are calculated. All possible Feynman diagrams are taken into account to construct the matrix element for either of the processes. In the second process all three type of neutrinos are considered. The significance of these processes are discussed briefly.

  6. Photon-photon collisions

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, S.J.

    1985-01-01

    The study of photon-photon collisions has progressed enormously, stimulated by new data and new calculational tools for QCD. In the future we can expect precise determinations of ..cap alpha../sub s/ and ..lambda../sup ms/ from the ..gamma..*..gamma.. ..-->.. ..pi../sup 0/ form factor and the photon structure function, as well as detailed checks of QCD, determination of the shape of the hadron distribution amplitudes from ..gamma gamma.. ..-->.. H anti H, reconstruction of sigma/sub ..gamma gamma../ from exclusive channels at low W/sub ..gamma gamma../, definitive studies of high p/sub T/ hadron and jet production, and studies of threshold production of charmed systems. Photon-photon collisions, along with radiative decays of the psi and UPSILON, are ideal for the study of multiquark and gluonic resonances. We have emphasized the potential for resonance formation near threshold in virtually every hadronic exclusive channel, including heavy quark states c anti c c anti c, c anti c u anti u, etc. At higher energies SLC, LEP, ...) parity-violating electroweak effects and Higgs production due to equivalent Z/sup 0/ and W/sup + -/ beams from e ..-->.. eZ/sup 0/ and e ..-->.. nu W will become important. 44 references.

  7. Linearly polarized photons at MAMI (Mainz)

    Science.gov (United States)

    Lohmann, D.; Peise, J.; Ahrens, J.; Anthony, I.; Arends, H.-J.; Beck, R.; Crawford, R.; Hünger, A.; Kaiser, K. H.; Kellie, J. D.; Klümper, Ch.; Krahn, P.; Kraus, A.; Ludwig, U.; Schumacher, M.; Selke, O.; Schmitz, M.; Schneider, M.; Wissmann, F.; Wolf, S.

    1994-04-01

    Coherent bremsstrahlung is produced using the 855 MeV electron beam of the Mainz three-stage racetrack microtron MAMI and a diamond crystal inserted as a radiator into the MAMI tagging system. By counting only the electrons on the tagger ladder an intensity spectrum ranging from 50 MeV to 800 MeV was obtained with good statistical accuracy in a running time of 2 s. This short running time makes it possible to measure a complete intensity pattern versus photon energy for different orientations of the diamond crystal in about 15 minutes. By comparing these measured intensity patterns with calculations it becomes possible to precisely align the crystal axes with respect to the axes of the goniometer. Relative intensities of coherent bremsstrahlung are determined experimentally by normalizing the diamond data to data obtained with an amorphous Ni radiator. Good agreement is obtained between experiment and prediction when taking into account the beam divergence, multiple scattering of electrons in the radiator, the Z dependence of the bremsstrahlung spectrum and the finite Debye temperature of diamond. With a collimated photon beam having an aperture of half the characteristic angle degrees of linear polarization appear to be possible ranging from 80% at 200 MeV over 65% at 300 MeV and 55% at 400 MeV to 35% at 500 MeV.

  8. Soft photon yield in nuclear interactions

    CERN Document Server

    Kokoulina, E

    2015-01-01

    First results of study of a soft photon yield at Nuclotron (LHEP, JINR) in nucleus-nucleus collisions at 3.5 GeV per nucleon are presented. These photons are registered by an BGO electromagnetic calorimeter built by SVD-2 Collaboration. The obtained spectra confirm the excessive yield in the energy region less than 50 MeV in comparison with theoretical estimations and agree with previous experiments at high-energy interactions.

  9. Photon technology. Hard photon technology; Photon technology. Hard photon gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    Research results of hard photon technology have been summarized as a part of novel technology development highly utilizing the quantum nature of photon. Hard photon technology refers to photon beam technologies which use photon in the 0.1 to 200 nm wavelength region. Hard photon has not been used in industry due to the lack of suitable photon sources and optical devices. However, hard photon in this wavelength region is expected to bring about innovations in such areas as ultrafine processing and material synthesis due to its atom selective reaction, inner shell excitation reaction, and spatially high resolution. Then, technological themes and possibility have been surveyed. Although there are principle proposes and their verification of individual technologies for the technologies of hard photon generation, regulation and utilization, they are still far from the practical applications. For the photon source technology, the laser diode pumped driver laser technology, laser plasma photon source technology, synchrotron radiation photon source technology, and vacuum ultraviolet photon source technology are presented. For the optical device technology, the multi-layer film technology for beam mirrors and the non-spherical lens processing technology are introduced. Also are described the reduction lithography technology, hard photon excitation process, and methods of analysis and measurement. 430 refs., 165 figs., 23 tabs.

  10. The photoresponse of stable N=82 nuclei below 10 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Volz, S. [Institut fuer Kernphysik, TU Darmstadt, Schlossgartenstrasse 9, D-64289 Darmstadt (Germany)]. E-mail: volz@ikp.tu-darmstadt.de; Tsoneva, N. [Institut fuer Theoretische Physik, Universitaet Giessen, Heinrich-Buff-Ring 16, D-35392 Giessen (Germany); Institute for Nuclear Research and Nuclear Energy, 1784 Sofia (Bulgaria); Babilon, M. [Institut fuer Kernphysik, TU Darmstadt, Schlossgartenstrasse 9, D-64289 Darmstadt (Germany); Elvers, M. [Institut fuer Kernphysik, TU Darmstadt, Schlossgartenstrasse 9, D-64289 Darmstadt (Germany); Hasper, J. [Institut fuer Kernphysik, TU Darmstadt, Schlossgartenstrasse 9, D-64289 Darmstadt (Germany); Herzberg, R.-D. [Department of Physics, The University of Liverpool, Liverpool L69 7ZE (United Kingdom); Lenske, H. [Institut fuer Theoretische Physik, Universitaet Giessen, Heinrich-Buff-Ring 16, D-35392 Giessen (Germany); Lindenberg, K. [Institut fuer Kernphysik, TU Darmstadt, Schlossgartenstrasse 9, D-64289 Darmstadt (Germany); Savran, D. [Institut fuer Kernphysik, TU Darmstadt, Schlossgartenstrasse 9, D-64289 Darmstadt (Germany); Zilges, A. [Institut fuer Kernphysik, TU Darmstadt, Schlossgartenstrasse 9, D-64289 Darmstadt (Germany)

    2006-11-27

    High resolution photon scattering experiments were performed at the 10 MeV bremsstrahlung facility of the electron accelerator S-DALINAC at TU Darmstadt to investigate the semi-magic N=82 nuclei {sup 138}Ba, {sup 140}Ce, {sup 142}Nd and {sup 144}Sm. Energies and absolute strengths of dipole transitions below 10 MeV were determined in a model independent way. A concentration of electric dipole excitations exhausting up to 1% of the isovector E1 energy weighted sum rule is observed in all four nuclei around 6.5 MeV. Calculations in the framework of the Quasiparticle-Phonon Model (QPM) reproduce the gross experimental features.

  11. Photonuclear reaction based high-energy x-ray spectrometer to cover from 2 MeV to 20 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Sakata, S., E-mail: sakata-s@ile.osaka-u.ac.jp; Arikawa, Y.; Kojima, S.; Ikenouchi, T.; Nagai, T.; Abe, Y.; Inoue, H.; Morace, A.; Utsugi, M.; Nishimura, H.; Nakai, M.; Shiraga, H.; Fujioka, S.; Azechi, H. [Institute of Laser Engineering, Osaka University, Suita 565-0871 (Japan); Kato, R. [Institute of Scientific and Industrial Research, Osaka University, Ibaraki 565-0047 (Japan)

    2014-11-15

    A photonuclear-reaction-based hard x-ray spectrometer is developed to measure the number and energy spectrum of fast electrons generated by interactions between plasma and intense laser light. In this spectrometer, x-rays are converted to neutrons through photonuclear reactions, and the neutrons are counted with a bubble detector that is insensitive to x-rays. The spectrometer consists of a bundle of hard x-ray detectors that respond to different photon-energy ranges. Proof-of-principle experiment was performed on a linear accelerator facility. A quasi-monoenergetic electron bunch (N{sub e} = 1.0 × 10{sup −6} C, E{sub e} = 16 ± 0.32 MeV) was injected into a 5-mm-thick lead plate. Bremsstrahlung x-rays, which emanate from the lead plate, were measured with the spectrometer. The measured spectral shape and intensity agree fairly well with those computed with a Monte Carlo simulation code. The result shows that high-energy x-rays can be measured absolutely with a photon-counting accuracy of 50%–70% in the energy range from 2 MeV to 20 MeV with a spectral resolution (Δhν/hν) of about 15%. Quantum efficiency of this spectrometer was designed to be 10{sup −7}, 10{sup −4}, 10{sup −5}, respectively, for 2–10, 11–15, and 15–25 MeV of photon energy ranges.

  12. Nuclear photonics

    Science.gov (United States)

    Habs, D.; Günther, M. M.; Jentschel, M.; Thirolf, P. G.

    2012-07-01

    With the planned new γ-beam facilities like MEGa-ray at LLNL (USA) or ELI-NP at Bucharest (Romania) with 1013 γ/s and a band width of ΔEγ/Eγ≈10-3, a new era of γ beams with energies up to 20MeV comes into operation, compared to the present world-leading HIγS facility at Duke University (USA) with 108 γ/s and ΔEγ/Eγ≈3ṡ10-2. In the long run even a seeded quantum FEL for γ beams may become possible, with much higher brilliance and spectral flux. At the same time new exciting possibilities open up for focused γ beams. Here we describe a new experiment at the γ beam of the ILL reactor (Grenoble, France), where we observed for the first time that the index of refraction for γ beams is determined by virtual pair creation. Using a combination of refractive and reflective optics, efficient monochromators for γ beams are being developed. Thus, we have to optimize the total system: the γ-beam facility, the γ-beam optics and γ detectors. We can trade γ intensity for band width, going down to ΔEγ/Eγ≈10-6 and address individual nuclear levels. The term "nuclear photonics" stresses the importance of nuclear applications. We can address with γ-beams individual nuclear isotopes and not just elements like with X-ray beams. Compared to X rays, γ beams can penetrate much deeper into big samples like radioactive waste barrels, motors or batteries. We can perform tomography and microscopy studies by focusing down to μm resolution using Nuclear Resonance Fluorescence (NRF) for detection with eV resolution and high spatial resolution at the same time. We discuss the dominating M1 and E1 excitations like the scissors mode, two-phonon quadrupole octupole excitations, pygmy dipole excitations or giant dipole excitations under the new facet of applications. We find many new applications in biomedicine, green energy, radioactive waste management or homeland security. Also more brilliant secondary beams of neutrons and positrons can be produced.

  13. Inclusive Dark Photon Search at LHCb

    CERN Document Server

    Ilten, Philip; Thaler, Jesse; Williams, Mike; Xue, Wei

    2016-01-01

    We propose an inclusive search for dark photons $A'$ at the LHCb experiment based on both prompt and displaced di-muon resonances. Because the couplings of the dark photon are inherited from the photon via kinetic mixing, the dark photon $A' \\to \\mu^+ \\mu^-$ rate can be directly inferred from the off-shell photon $\\gamma^* \\to \\mu^+ \\mu^-$ rate, making this a fully data-driven search. For Run 3 of the LHC, we estimate that LHCb will have sensitivity to large regions of the unexplored dark-photon parameter space, especially in the 210-520 MeV and 10-40 GeV mass ranges. This search leverages the excellent invariant-mass and vertex resolution of LHCb, along with its unique particle-identification and real-time data-analysis capabilities.

  14. Searches for dark photons at the Mainz Microtron

    Energy Technology Data Exchange (ETDEWEB)

    Merkel, H.; Achenbach, P.; Gayoso, C. Ayerbe; Beranek, T.; Bernauer, J. C.; Böhm, R.; Correa, L.; Denig, A.; Distler, M. O.; Esser, A.; Gómez, M.; Kegel, S.; Kohl, Y.; Mihovilovič, M.; Middleton, D. G.; Müller, U.; Nungesser, L.; Pochodzalla, J.; Rohrbeck, M.; Majos, S. Sánchez [Institut für Kernphysik, Johannes Gutenberg-Universität, D-55099 Mainz (Germany); and others

    2013-11-07

    The A1 Collaboration at the Mainz Microtron (MAMI) operates high resolution spectrometers at very high luminosities for fixed target electron scattering experiments. The setup is well suited for the search for dark photons in the mass range between 50 MeV and 300 MeV. In these experiments, a possible dark photon would appear as a sharp peak in the mass spectrum of di-lepton electro-production. In this presentation the potential of the setup is presented and the possibilities for future experiments for dark photon searches at MAMI are discussed.

  15. Microwave Photonics

    OpenAIRE

    Seeds, A.J.; Liu, C. P.; T. Ismail; Fice, M. J.; Pozzi, F; Steed, R. J.; Rouvalis, E.; Renaud, C.C.

    2010-01-01

    Microwave photonics is the use of photonic techniques for the generation, transmission, processing and reception of signals having spectral components at microwave frequencies. This tutorial reviews the technologies used and gives applications examples.

  16. Polarization sensitivity of a segmented HPGe detector up to 10 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Hutter, C.; Babilon, M.; Bayer, W.; Galaviz, D.; Hartmann, T.; Mohr, P.; Mueller, S.; Rochow, W.; Savran, D.; Sonnabend, K.; Vogt, K.; Volz, S.; Zilges, A. E-mail: zilges@ikp.tu-darmstadt.de

    2002-08-21

    Linear {gamma}-ray polarization can be measured using segmented germanium detectors. The polarization sensitivity of the Compton scattering process leads to asymmetries in the signals of a segmented detector. We have measured the polarization sensitivity of a four-fold segmented large volume germanium detector up to photon energies of approximately 10 MeV for the first time. The detector and its performance are compared to smaller Compton polarimeters which have been analyzed in previous work. A possible application of the described Compton polarimeter will be parity assignments in photon scattering experiments.

  17. Monte Carlo uncertainty analysis of germanium detector response to gamma-rays with energies below 1 MeV

    NARCIS (Netherlands)

    Maleka, PP; Maucec, M

    2005-01-01

    Monte Carlo method was used to simulate the pulse-height response function of high-precision germanium (HPGe) detector for photon energies below 1 MeV. The calculations address the uncertainty estimation due to inadequate specifications of source positioning and to variations in the detector's physi

  18. Polychromatic photons

    DEFF Research Database (Denmark)

    Keller, Ole

    2002-01-01

    A review is given of the space-time wave mechanics of single photons, a subject with an almost century long history. The Landau-Peierls photon wave function, which is related nonlocally to the electromagnetic field is first described, and thereafter the so-called energy wave function, based...... on the positive-frequency Riemann-Silberstein vectors, is discussed. Recent attempts to understand the birth process of a photon emerging from a single atom are summarized. The polychromatic photon concept is introduced, and it is indicated how the wave mechanics of polychromatic photons can be upgraded to wave...

  19. Photonic Lantern

    CERN Document Server

    Leon-Saval, Sergio; Bland-Hawthorn, Joss

    2015-01-01

    Photonic lanterns allow for a low-loss transformation of a multimode waveguide into a discrete number of single-mode waveguides and vice versa, thus, enabling the use of single-mode photonic technologies in multimode systems. In this review, we will discuss the theory and function of the photonic lantern, along with several different variants of the technology. We will also discuss some of its applications in more detail.

  20. Microwave photonics

    CERN Document Server

    Lee, Chi H

    2006-01-01

    Wireless, optical, and electronic networks continue to converge, prompting heavy research into the interface between microwave electronics, ultrafast optics, and photonic technologies. New developments arrive nearly as fast as the photons under investigation, and their commercial impact depends on the ability to stay abreast of new findings, techniques, and technologies. Presenting a broad yet in-depth survey, Microwave Photonics examines the major advances that are affecting new applications in this rapidly expanding field.This book reviews important achievements made in microwave photonics o

  1. <600> MeV synchro-cyclotron

    CERN Multimedia

    1971-01-01

    One of the 14 pancakes of the new magnet coils for the 600 MeV synchro-cyclotron which were wound and coated with epoxy resin on the CERN site. These new coils will replace the present ones which have been in use for more than 14 years but are now showing signs of deteriorations.

  2. MeV fullerene impacts on mica

    Energy Technology Data Exchange (ETDEWEB)

    Doebeli, M.; Scandella, L. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Ames, F. [Eidgenoessische Technische Hochschule, Zurich (Switzerland)

    1997-09-01

    Hillock heights on mica irradiated with MeV C{sub 60} ions have been investigated systematically. Results show that the small range of secondary particles along the track plays a crucial role in defect production. (author) figs., tab., refs.

  3. QED2 Photons Associated with QCD String Fragmentation

    CERN Document Server

    Wong, Cheuk-Yin

    2010-01-01

    Quarks interact with both chromodynamic and electromagnetic interactions. Consequently, QCD hadrons and QED photons will be produced simultaneously in the same process of QCD string fragmentation when a quark pulls away from an interacting antiquark at high energies. We are therefore motivated to explore whether QED2 photons are the source of anomalous soft photons associated with hadron production in high energy e+e- annihilations and hadron-hadron collisions. We find that the bosonized QED2 system of quarks with two flavors contains an isoscalar photon with a mass of about 25 MeV and an isovector (I,I_3)=(1,0) photon with a mass of about 44 MeV. These massive photons will be produced during the string fragmentation process in association with hadron production, with a greater probability for the production of isoscalar photons than isovector photons. How these QED2 photons may explain the anomalous soft photon data in Z^0 hadronic decay obtained by the DELPHI Collaboration will be discussed. Further experim...

  4. Response of detector modules of the neutron hodoscope SENECA to neutrons with energies 7-70 MeV

    Science.gov (United States)

    v. Edel, G.; Selke, O.; Pöch, C.; Smend, F.; Schumacher, M.; Nolte, R.; Schrewe, U.; Brede, H. J.; Schuhmacher, H.; Henneck, R.

    1993-07-01

    SENECA is a hodoscope for recoil neutrons from photoreactions on nuclei and nucleons in the photon energy range 50-900 MeV. It consists of 32 hexagonal scintillation detector modules in a honeycomb array. Differential detection efficiency spectra of a single module as well as the cross-talk between neighbouring modules were measured at neutron energies between 7 and 70 MeV. Neutron detection efficiencies were determined in the same energy range with an average experimental uncertainty of 7.6%. The experimental results agree with predictions from Monte Carlo codes within the limits of the experimental error.

  5. Hard photons in heavy-ion collisions: Direct or statistical

    Energy Technology Data Exchange (ETDEWEB)

    Herrmann, N.; Bock, R.; Emling, H.; Freifelder, R.; Gobbi, A.; Grosse, E.; Hildenbrand, K.D.; Kulessa, R.; Matulewicz, T.; Rami, F.; and others

    1988-04-18

    Photons with energies from 2 to 60 MeV have been measured in coincidence with binary fragments in the reaction /sup 92/Mo+/sup 92/Mo at an incident energy of 19.5A MeV. The rapid change of the ..gamma..-ray spectrum and multiplicity with the fragment total kinetic energy in the exit channel indicates that the ..gamma.. rays are emitted statistically by the highly excited fragments. Temperatures as high as 6 MeV are inferred

  6. Measurements of 1.9 MeV electron Bremsstrahlung

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Pino, Neivy; Cabal, Fatima Padilla; D' Alessandro, Katia [Instituto Superior de Tecnologias y Ciencias Aplicadas (InSTEC), La Habana (Cuba); Maidana, Nora Lia; Vanin, Vito Roberto; Martins, Marcos Nogueira; Malafronte, Alexandre; Bonini, Alfredo L. [Universidade de Sao Paulo (IF/USP), SP (Brazil). Inst. de Fisica. Lab. do Acelerador Linear; Sempau, Josep [Universitat Politecnica de Catalunya, Barcelona (Spain)

    2011-07-01

    Full text: Bremsstrahlung Cross section of 1.9 MeV electrons in Ti, Ag, and Au were measured at the Microtron accelerator of the IFUSP. Target mass surface density was in the range 0.1 to 1 mg/cm{sup 2} and the electron current varied from 3 to 30 nA, measured by a Faraday cup. The spectra were measured at three angles (30 deg; 90 deg and 60 deg) using a shielded p-type HPGe detector with an spectroscopy amplifier with pile-up rejection and a fast ADC. A 20 cm in length and 1.2 cm in diameter Pb collimator was placed in front of the detector to reduce the contribution of radiation scattered in the irradiation chamber or other background sources. With the goal of increasing the peak to total gamma-ray efficiency, the collimator hole was placed with its axis parallel to the coaxial detector symmetry axis, but displaced 1.4 cm to the right of the detector crystal axis. Hence, the Ge thickness exposed directly to the Bremsstrahlung beam was about 5 times bigger than that in the crystal axis, where the n-contact hole is located. The detector response functions were obtained by Monte Carlo simulations based on experimentally determined detector dimensions, in a procedure described in a companion paper submitted to this conference (Response function of a p-type Ge detector). Two energy bins: 50 keV and 1 keV were used in the Bremsstrahlung spectrum deconvolution. The first one was employed to determine the energy differential cross section from 0.1 to 1.9 MeV, and the second one for a more specific spectra study, in the high frequency limit or 'tip region'. The experimental spectrum was corrected for pile-up, with a simple model that assumes that the amplifier pile-up rejection resolving time is the same for all measured energies, and the photon background, measured with the target retracted from the beam. The Bremsstrahlung spectra B were obtained as: B = R{sup -}1 X E, where R is the matrix of the detector response function and E the recorded spectrum vector

  7. Praseodymium activation detector for measuring bursts of 14 MeV neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Meehan, Tim, E-mail: meehanbt@nv.doe.go [National Security Technologies, LLC, P.O. Box 98521, North Las Vegas, NV 89030 (United States); Hagen, E.C. [National Security Technologies, LLC, P.O. Box 98521, North Las Vegas, NV 89030 (United States); Ruiz, C.L.; Cooper, G.W. [Sandia National Laboratories, P.O. Box 5800, Albuquerque, NM 87185 (United States)

    2010-08-21

    A new, accurate, neutron activation detection scheme for measuring pulsed neutrons has been designed and tested. The detection system is sensitive to neutrons with energies above 10 MeV; importantly, it is insensitive to gamma radiation <10 MeV and to lower-energy (e.g., fission and thermal) neutrons. It is based upon the use of {sup 141}Pr, an element that has a single, naturally occurring isotope, a significant n,2n cross-section, and decays by positron emission that result in two coincident 511 keV photons. Neutron fluences are thus inferred by relating measured reaction product decay activity to fluence. Specific sample activity is measured using the sum-peak method to count gamma-ray coincidences from the annihilation of the positron decay products. The system was tested using 14 and 2.45 MeV neutron bursts produced by NSTec Dense Plasma Focus Laboratory fusion sources. Lead, copper, beryllium, and silver activation detectors were compared. The detection method allows measurement of 14 MeV neutron yield with a total error of {approx}18%.

  8. STAX. An Axion-like Particle Search with Microwave Photons

    CERN Document Server

    Ferretti, J

    2016-01-01

    We discuss an improved detection scheme for a light-shining-through-wall (LSW) experiment for axion-like particle searches. We propose to use: gyrotrons or klystrons, which can provide extremely intense photon fluxes at frequencies around 30 GHz; transition-edge-sensors (TES) single photon detectors in this frequency domain, with efficiency $\\approx1$; high quality factor Fabry-Perot cavities in the microwave domain, both on the photon-axion conversion and photon regeneration sides. We compute that present laboratory exclusion limits on axion-like particles might be improved by at least four orders of magnitude for axion masses $\\lesssim 0.02$ meV.

  9. Photon technology. Hard photon technology; Photon technology. Hard photon gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    For the application of photon to industrial technologies, in particular, a hard photon technology was surveyed which uses photon beams of 0.1-200nm in wavelength. Its features such as selective atom reaction, dense inner shell excitation and spacial high resolution by quantum energy are expected to provide innovative techniques for various field such as fine machining, material synthesis and advanced inspection technology. This wavelength region has been hardly utilized for industrial fields because of poor development of suitable photon sources and optical devices. The developmental meaning, usable time and issue of a hard photon reduction lithography were surveyed as lithography in ultra-fine region below 0.1{mu}m. On hard photon analysis/evaluation technology, the industrial use of analysis, measurement and evaluation technologies by micro-beam was viewed, and optimum photon sources and optical systems were surveyed. Prediction of surface and surface layer modification by inner shell excitation, the future trend of this process and development of a vacuum ultraviolet light source were also surveyed. 383 refs., 153 figs., 17 tabs.

  10. Probing a dark photon using rare leptonic kaon and pion decays

    Science.gov (United States)

    Chiang, Cheng-Wei; Tseng, Po-Yan

    2017-04-01

    Rare leptonic kaon and pion decays K+ (π+) →μ+νμe+e- can be used to probe a dark photon of mass O (10) MeV, with the background coming from the mediation of a virtual photon. This is most relevant for the 16.7-MeV dark photon proposed to explain a 6.8σ anomaly recently observed in 8Be transitions by the Atomki Collaboration. We evaluate the reach of future experiments for the dark photon with vectorial couplings to the standard model fermions except for the neutrinos, and show that a great portion of the preferred 16.7-MeV dark photon parameter space can be decisively probed. We also show the use of angular distributions to further distinguish the signal from the background.

  11. From soft photon study at Nuclotron and U-70 to NICA. Soft photons

    Energy Technology Data Exchange (ETDEWEB)

    Ardashev, E.; Golovkin, V.; Golovnya, S.; Gorokhov, S.; Kholodenko, A.; Kiryakov, A.; Lobanov, I.; Polkovnikov, M.; Ronzhin, V.; Ryadovikov, V.; Tsyupa, Yu.; Vorobiev, A. [Institute of High Energy Physics, Protvino (Russian Federation); Avdeichikov, V.; Balandin, V.; Dunin, V.; Gavrishchuk, O.; Isupov, A.; Kokoulina, E.; Kuzmin, N.; Nikitin, V.; Petukhov, Yu.; Reznikov, S.; Rogov, V.; Rufanov, I.A.; Zhidkov, N.; Zolin, L. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Bogdanova, G.; Popov, V.; Volkov, V. [Lomonosov Moscow State University, Scobeltsyn Institute of Nuclear Physics, Moscow (Russian Federation); Kazakov, A. [Smolensk State University, Smolensk (Russian Federation); Kutov, A. [DM Komi SC UrD RAS, Syktyvkar (Russian Federation); Pokatashkin, G. [Gomel State University, Gomel (Belarus)

    2016-08-15

    Experimental and theoretical studies of direct photon production in hadronic collisions essentially expand our insights in multiparticle production mechanisms. These photons are useful probes to investigate nuclear matter at all stages of the interaction. Soft photons play a particular role in these studies. Until now we have no explanation for the experimentally observed excess of soft photons. These photons have low transverse momenta p{sub T} < 0.1 GeV/c, vertical stroke x vertical stroke < 0.01. In this domain their yield exceeds the theoretical estimates by 5-8 times. The registration of soft photons at Nuclotron (LHEP, JINR) has been carried out by the electromagnetic calorimeter built by the SVD-2 Collaboration. Soft photon electromagnetic calorimeter was tested at U-70, IHEP (Protvino). For the first time the soft photon yield at interactions of 3.5 A GeV/c per nucleon deuterium and lithium beams has been measured. The obtained energy spectra confirm the increased yield of soft photons with their energy less than 50 MeV (in the laboratory system) in comparison with theoretical predictions and agree with previous experiments at high-energy interactions. It is planned to continue soft photon study at the future accelerator complex NICA with heavy-ion beams. (orig.)

  12. Photonuclear and Radiation Effects Testing with a Refurbished 20 MeV Medical Electron Linac

    CERN Document Server

    Webb, Timothy; Beezhold, Wendland; De Veaux, Linda C; Harmon, Frank; Petrisko, Jill E; Spaulding, Randy

    2005-01-01

    An S-band 20 MeV electron linear accelerator formerly used for medical applications has been recommissioned to provide a wide range of photonuclear activation studies as well as various radiation effects on biological and microelectronic systems. Four radiation effect applications involving the electron/photon beams are described. Photonuclear activation of a stable isotope of oxygen provides an active means of characterizing polymer degradation. Biological irradiations of microorganisms including bacteria were used to study total dose and dose rate effects on survivability and the adaptation of these organisms to repeated exposures. Microelectronic devices including bipolar junction transistors (BJTs) and diodes were irradiated to study photocurrent from these devices as a function of peak dose rate with comparisons to computer modeling results. In addition, the 20 MeV linac may easily be converted to a medium energy neutron source which has been used to study neutron damage effects on transistors.

  13. Hallo photons calls photon; Allo photon appelle photon

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1997-09-01

    When a pair of photons is created, it seems that these 2 photons are bound together by a mysterious link. This phenomenon has been discovered at the beginning of the seventies. In this new experiment the 2 photons are separated and have to follow different ways through optic cables until they face a quantum gate. At this point they have to chose between a short and a long itinerary. Statistically they have the same probability to take either. In all cases the 2 photons agree to do the same choice even if the 2 quantum gates are distant of about 10 kilometers. Some applications in ciphering and coding of messages are expected. (A.C.)

  14. Photon generator

    Science.gov (United States)

    Srinivasan-Rao, Triveni

    2002-01-01

    A photon generator includes an electron gun for emitting an electron beam, a laser for emitting a laser beam, and an interaction ring wherein the laser beam repetitively collides with the electron beam for emitting a high energy photon beam therefrom in the exemplary form of x-rays. The interaction ring is a closed loop, sized and configured for circulating the electron beam with a period substantially equal to the period of the laser beam pulses for effecting repetitive collisions.

  15. Microwave photonics

    CERN Document Server

    Lee, Chi H

    2013-01-01

    Microwave photonics continues to see rapid growth. The integration of optical fiber and wireless networks has become a commercial reality and is becoming increasingly pervasive. Such hybrid technology will lead to many innovative applications, including backhaul solutions for mobile networks and ultrabroadband wireless networks that can provide users with very high bandwidth services. Microwave Photonics, Second Edition systematically introduces important technologies and applications in this emerging field. It also reviews recent advances in micro- and millimeter-wavelength and terahertz-freq

  16. Photonic lanterns

    Science.gov (United States)

    Leon-Saval, Sergio G.; Argyros, Alexander; Bland-Hawthorn, Joss

    2013-12-01

    Multimode optical fibers have been primarily (and almost solely) used as "light pipes" in short distance telecommunications and in remote and astronomical spectroscopy. The modal properties of the multimode waveguides are rarely exploited and mostly discussed in the context of guiding light. Until recently, most photonic applications in the applied sciences have arisen from developments in telecommunications. However, the photonic lantern is one of several devices that arose to solve problems in astrophotonics and space photonics. Interestingly, these devices are now being explored for use in telecommunications and are likely to find commercial use in the next few years, particularly in the development of compact spectrographs. Photonic lanterns allow for a low-loss transformation of a multimode waveguide into a discrete number of single-mode waveguides and vice versa, thus enabling the use of single-mode photonic technologies in multimode systems. In this review, we will discuss the theory and function of the photonic lantern, along with several different variants of the technology. We will also discuss some of its applications in more detail. Furthermore, we foreshadow future applications of this technology to the field of nanophotonics.

  17. Channeling and coherent bremsstrahlung effects for relativistic positrons and electrons. [16 to 28 MeV, orientation

    Energy Technology Data Exchange (ETDEWEB)

    Walker, R. L.

    1976-03-22

    Channeling of positrons in single crystals of silicon was observed in transmission and scattering measurements for incident energies from 16 to 28 MeV. In addition, the spectral dependence upon crystal orientation of the forward coherent bremsstrahlung produced by beams of 28-MeV positrons and electrons incident upon a 5 ..mu..m thick single crystal of silicon was measured with a NaI photon spectrometer. Effects of channeling and perhaps of the nonvalidity of the first Born approximation were observed for beam directions near the (111) axis of the crystal, and coherent peaks near 0.5 MeV were observed for a compound interference direction, in agreement with first-order theoretical calculations. 32 fig.

  18. Measurement of eta photoproduction on the proton from threshold to 1500 MeV

    CERN Document Server

    Bartalini, O; Bocquet, J P; calvat, P; Capogni, M; Casano, L; Castoldi, M; D'Angelo, A; Didelez, J P; Di Salvo, R; Fantini, A; Franco, D; Gaulard, C; Gervino, G; Ghio, F; Giardina, G; Girolami, B; Giusa, A; Guidal, M; Hourany, E; Kunne, Ronald Alexander; Lapik, A; Levi-Sandri, P; Llères, A; Mammoliti, F; Mandaglio, G; Moricciani, D; Mushkarenkov, A N; Nedorezov, V; Nicoletti, L; Perrin, C; Randieri, C; Rebreyend, D; Renard, F; Rudnev, N; Russew, T; Russo, G; Schärf, C; Sperduto, M L; Sutera, M C; Turinge, A; Vegna, V

    2007-01-01

    Beam asymmetry and differential cross section for the reaction gamma+p->eta+p were measured from production threshold to 1500 MeV photon laboratory energy. The two dominant neutral decay modes of the eta meson, eta->2g and eta->3pi0, were analyzed. The full set of measurements is in good agreement with previously published results. Our data were compared with three models. They all fit satisfactorily the results but their respective resonance contributions are quite different. The possible photoexcitation of a narrow state N(1670) was investigated and no evidence was found.

  19. From soft photon study at Nuclotron and U-70 to NICA. Soft photons

    Science.gov (United States)

    Ardashev, E.; Avdeichikov, V.; Balandin, V.; Bogdanova, G.; Dunin, V.; Gavrishchuk, O.; Golovkin, V.; Golovnya, S.; Gorokhov, S.; Isupov, A.; Kazakov, A.; Kholodenko, A.; Kiryakov, A.; Kokoulina, E.; Kutov, A.; Kuzmin, N.; Lobanov, I.; Nikitin, V.; Petukhov, Yu.; Pokatashkin, G.; Polkovnikov, M.; Popov, V.; Reznikov, S.; Rogov, V.; Ronzhin, V.; Rufanov, I. A.; Ryadovikov, V.; Tsyupa, Yu.; Volkov, V.; Vorobiev, A.; Zhidkov, N.; Zolin, L.

    2016-08-01

    Experimental and theoretical studies of direct photon production in hadronic collisions essentially expand our insights in multiparticle production mechanisms. These photons are useful probes to investigate nuclear matter at all stages of the interaction. Soft photons play a particular role in these studies. Until now we have no explanation for the experimentally observed excess of soft photons. These photons have low transverse momenta pT SVD-2 Collaboration. Soft photon electromagnetic calorimeter was tested at U-70, IHEP (Protvino). For the first time the soft photon yield at interactions of 3.5 A GeV/ c per nucleon deuterium and lithium beams has been measured. The obtained energy spectra confirm the increased yield of soft photons with their energy less than 50MeV (in the laboratory system) in comparison with theoretical predictions and agree with previous experiments at high-energy interactions. It is planned to continue soft photon study at the future accelerator complex NICA with heavy-ion beams.

  20. Photonic crystals

    CERN Document Server

    Busch, Kurt; Wehrspohn, Ralf B; Föll, Helmut

    2006-01-01

    The majority of the contributions in this topically edited book stems from the priority program SPP 1113 ""Photonische Kristalle"" run by the Deutsche Forschungsgemeinschaft (DFG), resulting in a survey of the current state of photonic crystal research in Germany. The first part of the book describes methods for the theoretical analysis of their optical properties as well as the results. The main part is dedicated to the fabrication, characterization and modeling of two- and three-dimensional photonic crystals, while the final section presents a wide spectrum of applications: gas sensors, micr

  1. 42 MeV bremsstrahlung spectrum analysis by a photoactivation method

    Energy Technology Data Exchange (ETDEWEB)

    Calzado, A.; Vano, E.; Delgado, V.; Gonzalez, L. (Universidad Complutense de Madrid (Spain). Catedra de Fisica Medica; Junta de Energia Nuclear, Madrid (Spain). Inst. de Estudios Nucleares)

    1984-08-01

    The evaluation of 42 MeV, bremsstrahlung spectra from a clinical betatron by using the photoactivation method is described. Photonuclear reactions, mainly of the (..gamma.., n) type, are used as activation detectors. After measurements of photon-induced activities from residual nuclei are performed, the spectral distribution of photons is evaluated by solving the unfolding problem. The latter is carried out through the use of two independent methods, orthonormal expansion and Monte Carlo. In both cases prior conditions to the solution are imposed. Spectra evaluated by both methods and making use of two different size flattening filters are presented. An empirical method to estimate the 'effective' thickness of the Pt target is described.

  2. Photonic crystals principles and applications

    CERN Document Server

    Gong, Qihuang

    2013-01-01

    IntroductionPrimary Properties of Photonic CrystalsFabrication of Photonic CrystalsPhotonic Crystal All-Optical SwitchingTunable Photonic Crystal FilterPhotonic Crystal LaserPhotonic Crystal Logic DevicesPhotonic Crystal Sensors

  3. Photonic Bandgaps in Photonic Molecules

    Science.gov (United States)

    Smith, David D.; Chang, Hongrok; Gates, Amanda L.; Fuller, Kirk A.; Gregory, Don A.; Witherow, William K.; Paley, Mark S.; Frazier, Donald O.; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    This talk will focus on photonic bandgaps that arise due to nearly free photon and tight-binding effects in coupled microparticle and ring-resonator systems. The Mie formulation for homogeneous spheres is generalized to handle core/shell systems and multiple concentric layers in a manner that exploits an analogy with stratified planar systems, thereby allowing concentric multi-layered structures to be treated as photonic bandgap (PBG) materials. Representative results from a Mie code employing this analogy demonstrate that photonic bands arising from nearly free photon effects are easily observed in the backscattering, asymmetry parameter, and albedo for periodic quarter-wave concentric layers, though are not readily apparent in extinction spectra. Rather, the periodicity simply alters the scattering profile, enhancing the ratio of backscattering to forward scattering inside the bandgap, in direct analogy with planar quarter-wave multilayers. PBGs arising from tight-binding may also be observed when the layers (or rings) are designed such that the coupling between them is weak. We demonstrate that for a structure consisting of N coupled micro-resonators, the morphology dependent resonances split into N higher-Q modes, in direct analogy with other types of oscillators, and that this splitting ultimately results in PBGs which can lead to enhanced nonlinear optical effects.

  4. LIPSS results for photons coupling to light neutral scalar bosons

    Energy Technology Data Exchange (ETDEWEB)

    Andrei Afanasev; Oliver K. Baker; Kevin Beard; George Biallas; James Boyce; Minarni Minarni; Roopchan Ramdon; Michelle D. Shinn; Penny Slocum

    2008-06-01

    The LIPSS search for a light neutral scalar boson coupling to optical photons is reported. The search covers a region of parameter space of approximately 1.0 meV and coupling strength greater than 10^-6 GeV^-1. The LIPSS results show no evidence for scalar coupling in this region of parameter space.

  5. Validation of the GEANT4 simulation of bremsstrahlung from thick targets below 3 MeV

    Science.gov (United States)

    Pandola, L.; Andenna, C.; Caccia, B.

    2015-05-01

    The bremsstrahlung spectra produced by electrons impinging on thick targets are simulated using the GEANT4 Monte Carlo toolkit. Simulations are validated against experimental data available in literature for a range of energy between 0.5 and 2.8 MeV for Al and Fe targets and for a value of energy of 70 keV for Al, Ag, W and Pb targets. The energy spectra for the different configurations of emission angles, energies and targets are considered. Simulations are performed by using the three alternative sets of electromagnetic models that are available in GEANT4 to describe bremsstrahlung. At higher energies (0.5-2.8 MeV) of the impinging electrons on Al and Fe targets, GEANT4 is able to reproduce the spectral shapes and the integral photon emission in the forward direction. The agreement is within 10-30%, depending on energy, emission angle and target material. The physics model based on the Penelope Monte Carlo code is in slightly better agreement with the measured data than the other two. However, all models over-estimate the photon emission in the backward hemisphere. For the lower energy study (70 keV), which includes higher-Z targets, all models systematically under-estimate the total photon yield, providing agreement between 10% and 50%. The results of this work are of potential interest for medical physics applications, where knowledge of the energy spectra and angular distributions of photons is needed for accurate dose calculations with Monte Carlo and other fluence-based methods.

  6. Photon differentials

    DEFF Research Database (Denmark)

    Schjøth, Lars; Revall Frisvad, Jeppe; Erleben, Kenny;

    2007-01-01

    illumination features. This is often not desirable as these may lose clarity or vanish altogether. We present an accurate method for reconstruction of indirect illumination with photon mapping. Instead of reconstructing illumination using classic density estimation on finite points, we use the correlation...

  7. Semiconductor quantum optics with tailored photonic nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Laucht, Arne

    2011-06-15

    This thesis describes detailed investigations of the effects of photonic nanostructures on the light emission properties of self-assembled InGaAs quantum dots. Nanoscale optical cavities and waveguides are employed to enhance the interaction between light and matter, i.e. photons and excitons, up to the point where optical non-linearities appear at the quantum (single photon) level. Such non-linearities are an essential component for the realization of hardware for photon based quantum computing since they can be used for the creation and detection of non-classical states of light and may open the way to new genres of quantum optoelectronic devices such as optical modulators and optical transistors. For single semiconductor quantum dots in photonic crystal nanocavities we investigate the coupling between excitonic transitions and the highly localized mode of the optical cavity. We explore the non-resonant coupling mechanisms which allow excitons to couple to the cavity mode, even when they are not spectrally in resonance. This effect is not observed for atomic cavity quantum electrodynamics experiments and its origin is traced to phonon-assisted scattering for small detunings ({delta}E<{proportional_to}5 meV) and a multi-exciton-based, Auger-like process for larger detunings ({delta}E >{proportional_to}5 meV). For quantum dots in high-Q cavities we observe the coherent coupling between exciton and cavity mode in the strong coupling regime of light-matter interaction, probe the influence of pure dephasing on the coherent interaction at high excitation levels and high lattice temperatures, and examine the coupling of two spatially separated quantum dots via the exchange of real and virtual photons mediated by the cavity mode. Furthermore, we study the spontaneous emission properties of quantum dots in photonic crystal waveguide structures, estimate the fraction of all photons emitted into the propagating waveguide mode, and demonstrate the on-chip generation of

  8. Sub MeV Bosonic Dark Matter, Misalignment Mechanism and Galactic Dark Matter Halo Luminosities

    CERN Document Server

    Yang, Qiaoli

    2016-01-01

    We explore a scenario that the dark matter is a boson condensate created by the misalignment mechanism in which a spin zero boson (an axion like particle) and a spin one boson (the dark photon) are considered respectively. We find that although the sub MeV dark matter boson is extremely stable, the huge dark matter particle number in a galaxy halo makes the decaying signal detectable. A galaxy halo is a large structure bounded by gravity with a typical $\\sim10^{12}$ solar mass and its majority components are made of dark matter. For the axion like particle case, it decays via $\\phi\\to \\gamma\\gamma$ therefore the photon spectrum is monochromatic and for the dark photon case, it is a three body decay $A'\\to\\gamma\\gamma\\gamma$, however we find numerically that the photon spectrum is heavily peaked at $M/2$ thus could be a facility to observations. We also suggest a physical explanation for the three body decay spectrum by comparing the physics in the decay of orthopositronium. In addition, for both cases the dec...

  9. Measurements of photoneutrons produced by a 15 MeV electron linac for radiography applications

    Science.gov (United States)

    Huang, W. L.; Li, Q. F.; Lin, Y. Z.; Su, Q.; Luo, Y. S.

    2006-10-01

    Electrons (15 MeV) bombard a bremsstrahlung target to generate X-rays, which produces photoneutrons leading to radiation hazards and image blurring in radiography accelerators. Neutron measurements are very difficult in this type of accelerator system, due to the photon activation of high energy X-rays, the narrow pulse width of neutrons and the wide neutron spectrum. In order to study photoneutron problems, a series of experiments were conducted in our lab. At points 1 m away from the target in different directions, CR39s and BDPNDs were used to measure the neutron doses, the results of which showed that the ratios of the neutron dose to the photon dose were (0.062 ± 0.016) mSv/Gy X-ray and (0.082 ± 0.008) mSv/Gy X-ray respectively in the main X-ray beam, which agreed with Monte-Carlo simulation results within 20% and 10%. When the accelerator was equipped with shielding, activation foils were placed at a point 1 m away from the target in a 30° direction to the main beam to evaluate the activities induced by either photons or neutrons. The In foils indicated that the ratio of the fast neutron flux at this point to the photon dose at the isocenter was about (4.6 ± 0.05) × 10 4 n cm -2 Gy -1 X-ray, which agreed very well with the MCNP5 simulation.

  10. Validation of the Geant4 simulation of bremsstrahlung from thick targets below 3 MeV

    CERN Document Server

    Pandola, Luciano; Caccia, Barbara

    2014-01-01

    The bremsstrahlung spectra produced by electrons impinging on thick targets are simulated using the Geant4 Monte Carlo toolkit. Simulations are validated against experimental data available in literature for a range of energy between 0.5 and 2.8 MeV for Al and Fe targets and for a value of energy of 70 keV for Al, Ag, W and Pb targets. All three independent sets of electromagnetic models available in Geant4 to simulate bremsstrahlung are tested. A quantitative analysis is performed reproducing with each model the energy spectrum for the different configurations of emission angles, energies and targets. At higher energies (0.5-2.8 MeV) of the impinging electrons on Al and Fe targets, Geant4 is able to reproduce the spectral shapes and the integral photon emission in the forward direction (at better than 10%). The physics model based on the Penelope Monte Carlo code seems slightly preferable over the other two. However, all models over-estimate the photon emission in the backward hemisphere. For the lower energ...

  11. High intensity X/γ photon beams for nuclear physics and photonics

    Science.gov (United States)

    Serafini, L.; Alesini, D.; Bacci, N.; Bliss, N.; Cassou, K.; Curatolo, C.; Drebot, I.; Dupraz, K.; Giribono, A.; Petrillo, V.; Palumbo, L.; Vaccarezza, C.; Variola, A.; Zomer, F.

    2016-05-01

    In this manuscript we review the challenges of Compton backscattering sources in advancing photon beam performances in the 1 - 20 MeV energy range, underlining the design criteria bringing to maximum spectral luminosity and briefly describing the main achievements in conceiving and developing new devices (multi-bunch RF cavities and Laser recirculators) for the case of ELI-NP Gamma Beam System (ELI-NP-GBS).

  12. Bremsstrahlung production at 50 MeV in different target materials and configurations.

    Science.gov (United States)

    Sätherberg, A; Andreo, P; Karlsson, M

    1996-04-01

    A combination of Monte Carlo, convolution, and experimental techniques have been used to investigate bremsstrahlung production at 50 MeV in full-range targets to produce narrow elementary photon beams for scanning. Calculations using the ITS 3.0 Monte Carlo system for various target designs, including particle transport through the treatment head of an MM5O racetrack microtron and a water phantom, have been compared to experimental dose profiles from narrow photon beams at 10-cm depth in water. A reduction in the ITS 3.0 default substep size has been found necessary even for incomplete agreement, in consistency with the findings of Faddegon and Rogers [Nucl. Instrum. Meth. A 327, 556-565 (1993)] for a different experimental setup and energy using the previous version of ITS. Results show that the calculated shape of the tail of dose distributions from narrow photon beams agrees well with measurements, but CYLTRAN/ITS 3.0 fails to reproduce the central part of the distribution. The discrepancy at small angles, reported previously for EGS4 and ITS 2.1 simulations, possess a limitation to Monte Carlo simulations of narrow photon beams used in scanned systems of clinical accelerators. Radial dose profiles have been calculated by convolution of the energy fluence at the exit of the target with one polyenergetic Monte Carlo calculated dose kernel and also a database consisting of ten different dose kernels corresponding to different monoenergetic photon pencil beams for comparison. The agreement with the much slower fully detailed Monte Carlo calculations was better when using the database kernels than the polyenergetic kernel. Results for the mean energy, mean polar angle, and energy fluence at different depths within various targets have been obtained. These are discussed in the context of the design characteristics of bremsstrahlung targets with emphasis on their utilization for scanning photon beam techniques.

  13. 14 MeV neutrons physics and applications

    CERN Document Server

    Valkovic, Vladivoj

    2015-01-01

    Despite the often difficult and time-consuming effort of performing experiments with fast (14 MeV) neutrons, these neutrons can offer special insight into nucleus and other materials because of the absence of charge. 14 MeV Neutrons: Physics and Applications explores fast neutrons in basic science and applications to problems in medicine, the environment, and security.Drawing on his more than 50 years of experience working with 14 MeV neutrons, the author focuses on:Sources of 14 MeV neutrons, including laboratory size accelerators, small and sealed tube generators, well logging sealed tube ac

  14. Photon spectrometry in thermal neutron standard field

    CERN Document Server

    Kudo, K; Koshikawa, S; Toyokawa, H; Ohgaki, H; Matzke, M

    2002-01-01

    An NE213 liquid scintillation counter (5.08 cm in diameter and 5.08 cm long) with an LiF filter was used to measure the energy distribution of photons mixed in a thermal neutron field. The response function matrix of photons in an energy range up to 10 MeV was calculated by the EGS4/PRESTA code and properly folded with a resolution function. Pulse height spectra measured with a set of reference gamma-ray sources were compared to the calculated response function and agreed very well for all reference gamma-ray sources. The GRAVEL and MIEKE codes from the HEPRO program were used to unfold measured pulse height spectra. Energy distributions obtained by the unfolding were applied to evaluate the effective dose equivalent of photons mixed in a thermal neutron field.

  15. Photonic homeostatics

    Science.gov (United States)

    Liu, Timon C.; Li, Fan-Hui

    2010-11-01

    Photonic homeostatics is a discipline to study the establishment, maintenance, decay, upgrading and representation of function-specific homoestasis (FSH) by using photonics. FSH is a negative-feedback response of a biosystem to maintain the function-specific fluctuations inside the biosystem so that the function is perfectly performed. A stress may increase sirtuin 1 (SIRT1) activities above FSH-specific SIRT1 activity to induce a function far from its FSH. On the one hand, low level laser irradiation or monochromatic light (LLL) can not modulate a function in its FSH or a stress in its stress-specific homeostasis (StSH), but modulate a function far from its FSH or a stress far from its StSH. On the other hand, the biophotons from a biosystem with its function in its FSH should be less than the one from the biosystem with its function far from its FSH. The non-resonant interaction of low intensity laser irradiation or monochromatic light (LIL) and a kind of membrane protein can be amplified by all the membrane proteins if the function is far from its FSH. This amplification might hold for biophoton emission of the membrane protein so that the photonic spectroscopy can be used to represent the function far from its FSH, which is called photonomics.

  16. The low energy photon tagger NEPTUN: Toward a detailed study of the Pygmy dipole resonance with real photons

    Energy Technology Data Exchange (ETDEWEB)

    Semmler, Diego; Aumann, T.; Bauer, C.; Baumann, M.; Beckstein, M.; Beller, J.; Blecher, A.; Cvejin, N.; Duchene, M.; Hug, F.; Kahlbow, J.; Knoerzer, M.; Kreis, K.; Kremer, C.; Ries, P.; Romig, C.; Scheit, H.; Schnorrenberger, L.; Symochko, D.; Walz, C. [Institut fuer Kernphysik, Darmstadt (Germany); Lefol, R. [University of Saskatchewan, Saskatoon (Canada); Loeher, B. [ExtreMe Matter Institute EMMI and Research Division, Frankfurt (Germany); Institute for Advanced Studies FIAS, Frankfurt (Germany)

    2014-07-01

    The low energy photon tagger NEPTUN at the S-DALINAC delivers a quasi-monoenergetic photon beam between about 4 MeV and 20 MeV with a resolution of approximately 25 keV. Tagged photons provide the possibility to measure the dipole strength of nuclei in the energy range below and above the neutron threshold. The highly efficient LaBr{sub 3} based spectrometer GALATEA will be used to detect not only the direct decays to the ground state, but also cascading decays can be measured with suitable efficiency. We will measure (γ,n)- and (γ,nγ)-reactions with neutron detectors based on plastic scintillators. This talk provides an overview about setup and goals of the NEPTUN experiment as well as the current state of the commissioning phase. Planned optimizations of the setup, based on the results of a test beam time in June 2013, are also presented.

  17. Valine radiolysis by MeV ions

    Science.gov (United States)

    Da Silveira, Enio

    2016-07-01

    Valine, (CH3)2 CHCH (NH2) COOH, is a protein amino acid that has been identified in extraterrestrial environments and in the Murchison meteorite [1]. The knowledge of half-lives of small organic molecules under ionizing radiation is important for the setup of models describing the spread out of prebiotics across the Solar System or the Galaxy. We have investigated typical effects of MeV cosmic ray ions on prebiotic molecules in laboratory by impinging ions produced by the PUC-Rio Van de Graaff accelerator. Pure valine films, deposited by evaporation on KBr substrates, were irradiated by H ^{+}, He ^{+} and N ^{+} ion beams, from 0.5 to 1.5 MeV and up to a fluence of 10 ^{15} projectiles/cm ^{2}. The sample temperature was varied from 10 K to 300 K. The irradiation was interrupted several times for Mid-FTIR analysis of the sample. The main findings are: 1- The column density of the valine decreases exponentially with fluence. 2- In some cases, a second exponential appears in the beginning of irradiation; this feature has been attributed to sample compaction by the ion beam [2]. 3- Destruction cross sections of valine are in the 10 ^{-15} cm ^{2} range, while compaction cross sections are in the 10 ^{-14} cm ^{2} range. 4- Destruction cross section increases with the stopping power of the beam and also with the sample temperature. 5- Surprisingly, during the radiolysis of valine, just CO _{2} is seen by as a daughter molecule formed in the bulk. 6- After long beam fluence, also a CO peak appears in the infrared spectrum; this species is however interpreted as a fragment of the formed CO2 molecules. 7- Considering the flux ratio between laboratory experiments and actual galactic cosmic rays, half-life of valine is predicted for ISM conditions [3]. This work on pure valine is the first measurement of a series. New experiments are planned for determining cross sections of valine dissolved in H _{2}O or CO _{2}, inspired by the study performed for glycine [4]. [1] P

  18. 150 MeV fixed field alternating gradient (FFAG) accelerator

    CERN Document Server

    Nakano, J

    2002-01-01

    150 MeV FFAG accelerator is prototype for practical use. Fundamental development of FFAG, research of FFAG accelerator and its application for therapy are investigated. 150 MeV ring consists of 12 sector magnets. The distribution of magnetic field of 12 sector magnets is almost same. 12 MeV proton beam is generated by cyclotron and injection to 150 MeV FFAG. The injection system consists of 2 bump magnets, kicker magnet and septum electrode. RF accelerating cavity system using high-permeability magnetic substance with high magnetic permeability accelerates proton beam to 150 MeV, then the first operation aims at 250 Hz. Return Yoke Free magnet was developed for adjustment. 150 MeV FFAG magnet is constructed and 12 MeV proton beam acceleration is conformed. The final state of 150 MeV FFAG magnet is explained by calculation results. On cancer therapy by proton beam, the three dimensions spot scan method is proposed. (S.Y.)

  19. Linearly polarized photon beam at MAX-lab

    Energy Technology Data Exchange (ETDEWEB)

    Ganenko, V., E-mail: ganenko@kipt.kharkov.ua [National Science Center, Kharkov Institute of Physics and Technology, 61108 Kharkov (Ukraine); Brudvik, J. [MAX IV Laboratory, Lund University, SE-221 00 Lund (Sweden); Burdeinyi, D. [National Science Center, Kharkov Institute of Physics and Technology, 61108 Kharkov (Ukraine); Fissum, K. [Department of Physics, Lund University, SE-221 00 Lund (Sweden); Hansen, K. [MAX IV Laboratory, Lund University, SE-221 00 Lund (Sweden); Isaksson, L. [Department of Physics, Lund University, SE-221 00 Lund (Sweden); Livingston, K. [Department of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, Scotland (United Kingdom); Lundin, M. [MAX IV Laboratory, Lund University, SE-221 00 Lund (Sweden); Morokhovskii, V. [National Science Center, Kharkov Institute of Physics and Technology, 61108 Kharkov (Ukraine); Nilsson, B.; Pugachov, D. [MAX IV Laboratory, Lund University, SE-221 00 Lund (Sweden); Schroder, B. [MAX IV Laboratory, Lund University, SE-221 00 Lund (Sweden); Department of Physics, Lund University, SE-221 00 Lund (Sweden); Vashchenko, G. [National Science Center, Kharkov Institute of Physics and Technology, 61108 Kharkov (Ukraine)

    2014-11-01

    A linearly polarized photon beam has been produced at MAX-lab using the coherent bremsstrahlung of electrons with an energy of 192.6 MeV in a 0.1 mm thick diamond crystal. The intensity and shape of the coherent maxima and their dependence on the crystal orientation are similar to the features observed at higher electron energies (∼ 1 GeV) and are well described by coherent bremsstrahlung theory. The linear polarization of the uncollimated beam at the coherent peak energy ≈50–60 MeV is about 20% and can be increased to 40–45% if collimation of half the characteristic angle is used. At present the degree of polarization is high enough to allow the study of polarization observables in photo-nuclear reactions at MAX-lab in the energy range from Giant Dipole Resonance up to ≈80 MeV. -- Highlights: •A linearly polarized tagged photon beam has been produced at the MAX-lab facility. •The coherent bremsstrahlung spectra were measured for various crystal orientations. •The measured spectra are well described by the coherent bremsstrahlung theory. •The photon beam polarization can reach 50% at the Giant Resonance region. •Polarized beam provides performing nuclear experiments in the energy range 10–90 MeV.

  20. Nanowire photonics

    Directory of Open Access Journals (Sweden)

    Peter J. Pauzauskie

    2006-10-01

    Full Text Available The development of integrated electronic circuitry ranks among the most disruptive and transformative technologies of the 20th century. Even though integrated circuits are ubiquitous in modern life, both fundamental and technical constraints will eventually test the limits of Moore's law. Nanowire photonic circuitry constructed from myriad one-dimensional building blocks offers numerous opportunities for the development of next-generation optical information processors and spectroscopy. However, several challenges remain before the potential of nanowire building blocks is fully realized. We cover recent advances in nanowire synthesis, characterization, lasing, integration, and the eventual application to relevant technical and scientific questions.

  1. Probing a dark photon using rare leptonic kaon and pion decays

    Directory of Open Access Journals (Sweden)

    Cheng-Wei Chiang

    2017-04-01

    Full Text Available Rare leptonic kaon and pion decays K+(π+→μ+νμe+e− can be used to probe a dark photon of mass O(10 MeV, with the background coming from the mediation of a virtual photon. This is most relevant for the 16.7-MeV dark photon proposed to explain a 6.8σ anomaly recently observed in 8Be transitions by the Atomki Collaboration. We evaluate the reach of future experiments for the dark photon with vectorial couplings to the standard model fermions except for the neutrinos, and show that a great portion of the preferred 16.7-MeV dark photon parameter space can be decisively probed. We also show the use of angular distributions to further distinguish the signal from the background.

  2. RF Operation for the 100MeV Proton Linac

    Energy Technology Data Exchange (ETDEWEB)

    Seol, Kyung Tae; Kwon, Hyeok Jung; Kim, Dae Il; Kim, Han Sung; Song, Young Gi; Jang, Ji Ho; Cho, Yong Sub [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    The RF systems for the 100MeV linac were constructed. The HPRF system including klystrons, circulators, high power dummy loads, and waveguide components was installed at the klystron gallery, and the LLRF control systems including a commercial FPGA module and a LLRF analog chassis were also installed. The phase stability of the RF reference line was measured with S11 phase under temperature control. The RF systems for 100MeV linac have been operated for a beam commissioning, and the 100MeV proton beam has been supplied to users currently. The RF systems of the 100MeV proton linac for the KOMAC (KOrea Multi-purpose Accelerator Complex) were installed at the Gyeong-ju site. The 100MeV linac consists of a 3MeV RFQ, a 20MeV DTL with four tanks, two MEBT tanks, and seven 100MeV DTL tanks. For the 100MeV linac, nine sets of LLRF control systems and the HPRF systems including 1MW klystrons, circulators and waveguide components have been installed at the klystron gallery, and four high voltage converter modulators to drive nine klystrons have been installed at the modulator room. A RF reference system distributing 300MHz LO signal to each RF control system has also been installed with a temperature control system at the klystron gallery. The requirement of RF field control is within +/- 1% in RF amplitude and +/- 1 degree in RF phase. The RF systems have been operated for the beam commissioning. The installation and operation of the RF system for the 100MeV proton linac are presented in this paper.

  3. Neutron and photon spectra in LINACs.

    Science.gov (United States)

    Vega-Carrillo, H R; Martínez-Ovalle, S A; Lallena, A M; Mercado, G A; Benites-Rengifo, J L

    2012-12-01

    A Monte Carlo calculation, using the MCNPX code, was carried out in order to estimate the photon and neutron spectra in two locations of two linacs operating at 15 and 18 MV. Detailed models of both linac heads were used in the calculations. Spectra were estimated below the flattening filter and at the isocenter. Neutron spectra show two components due to evaporation and knock-on neutrons. Lethargy spectra under the filter were compared to the spectra calculated from the function quoted by Tosi et al. that describes reasonably well neutron spectra beyond 1 MeV, though tends to underestimate the energy region between 10(-6) and 1 MeV. Neutron and the Bremsstrahlung spectra show the same features regardless of the linac voltage.

  4. Activation analysis using {gamma} photons; Analyse par activation aux photons {gamma}

    Energy Technology Data Exchange (ETDEWEB)

    Engelmann, Ch. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-07-01

    This report summarizes all the data required for using photonuclear reactions in the field of analysis. After a brief review of the elementary properties of nuclear reactions induced by photon irradiation, the main characteristics are given of high energy (E > 20 MeV) Bremsstrahlung sources. The principle of activation analysis based on the use of photons is given. Actual examples of the analytic possibilities are described in detail, in particular in the case of the determination of very small quantities (< 10{sup -6}) of C, N, O and F. The influence of interfering nuclear reactions is discussed. (author) [French] Ce rapport se propose de resumer l'ensemble des connaissances indispensables pour l'utilisation des reactions photonucleaires a des fins analytiques. Apres quelques rappels concernant les proprietes elementaires des reactions nucleaires induites par irradiation dans les photons, les principales caracteristiques des sources de rayonnement de freinage de haute energie (E > 20 MeV)| sont donnees. Le principe de l'analyse par activation aux photons est rappele. Des exemples concrets sur les possibilites analytiques sont developpes, particulierement en ce qui concerne la determination de quantites tres faibles (< 10{sup -6}) de C, N, O et F. L'influence des reactions nucleaires parasites est discutee. (auteur)

  5. Nuclear Photonics

    CERN Document Server

    Habs, D; Jentschel, M; Thirolf, P G

    2012-01-01

    With new gamma-beam facilities like MEGa-ray at LLNL (USA) or ELI-NP at Bucharest with 10^13 g/s and a bandwidth of Delta E_g/E_g ~10^-3, a new era of g-beams with energies <=20 MeV comes into operation, compared to the present world-leading HIGS facility (Duke Univ., USA) with 10^8 g/s and Delta E_g/E_g~0.03. Even a seeded quantum FEL for g-beams may become possible, with much higher brilliance and spectral flux. At the same time new exciting possibilities open up for focused g-beams. We describe a new experiment at the g-beam of the ILL reactor (Grenoble), where we observed for the first time that the index of refraction for g-beams is determined by virtual pair creation. Using a combination of refractive and reflective optics, efficient monochromators for g-beams are being developed. Thus we have to optimize the system of the g-beam facility, the g-beam optics and g-detectors. We can trade g-intensity for band width, going down to Delta E_g/E_g ~ 10^-6 and address individual nuclear levels. 'Nuclear pho...

  6. Formation of the 0.511.-MeV line in solar flares. [statistical mechanics of line spectra for gamma rays

    Science.gov (United States)

    Crannell, C. J.; Joyce, G.; Ramaty, R.; Werntz, C.

    1976-01-01

    The gamma-ray line produced at 0.51-MeV was studied and is shown to be the result of either of free annihilation of positrons with electrons or of the decay of positronium by 2-photon emission. Positron annihilation from the bound state of positronium may also proceed by 3-photon emission, resulting in a continuum with energies up to 0.51-MeV. Accurate calculations of the rates of free annihilation and positronium formation in a solar-flare plasma are presented. Estimates of the positronium-formulation rates by charge exchange and the rates of dissociation and quenching are also considered. The temperature and density dependence of the ratio of 3-photon to 2-photon emission was obtained. It is shown that when the ratio of free electrons to neutral atoms in the plasma is approximately unity or greater, the Doppler width of the 0.51-MeV line is a function of the temperature of the annihilation region. For the small ion densities characteristics of the photosphere, the width is predominantly a function of the density.

  7. Revisiting Supernova 1987A Constraints on Dark Photons

    CERN Document Server

    Chang, Jae Hyeok; McDermott, Samuel D

    2016-01-01

    We revisit constraints on dark photons with masses below ~ 100 MeV from the observations of Supernova 1987A. If dark photons are produced in sufficient quantity, they reduce the amount of energy emitted in the form of neutrinos, in conflict with observations. For the first time, we include the effects of finite temperature and density on the kinetic-mixing parameter, epsilon, in this environment. This causes the constraints on epsilon to weaken with the dark-photon mass below ~ 15 MeV. For large-enough values of epsilon, it is well known that dark photons can be reabsorbed within the supernova. Since the rates of reabsorption processes decrease as the dark-photon energy increases, we point out that dark photons with energies above the Wien peak can escape without scattering, contributing more to energy loss than is possible assuming a blackbody spectrum. Furthermore, we estimate the systematic uncertainties on the cooling bounds by deriving constraints assuming one analytic and four different simulated temper...

  8. 40 CFR 60.130 - Applicability and designation of affected facility.

    Science.gov (United States)

    2010-07-01

    ... in secondary brass or bronze production plants: Reverberatory and electric furnaces of 1,000 kg (2205 lb) or greater production capacity and blast (cupola) furnaces of 250 kg/h (550 lb/h) or greater production capacity. Furnaces from which molten brass or bronze are cast into the shape of finished...

  9. Intense Combined Source of Neutrons and Photons for Interrogation Based on Compact Deuteron RF Accelerator

    Science.gov (United States)

    Kurennoy, S. S.; Garnett, R. W.; Rybarcyk, L. J.

    Interrogation of special nuclear materials can benefit from mobile sources providing significant fluxes of neutrons (108/s at 2.5 MeV, 1010/s at 14.1 MeV) and of photons (>1012/s at 1-3 MeV). We propose a source that satisfies these requirements simultaneously plus also provides, via the reaction 11B(d,n)12C(γ15.1), a significant flux of 15-MeV photons, which are highly penetrating and optimal for inducing photo-fission in actinides. The source is based on a compact (< 5 m) deuteron RF accelerator that delivers an average current of a few mA of deuterons at 3-4 MeV to a boron target. The accelerator consists of a short RFQ followed by efficient inter-digital H-mode structures with permanent-magnet-quadrupole beam focusing [Kurennoy et al. (2012)], which suit perfectly for deuteron acceleration at low energies. Our estimates, based on recent measurements [Taddeucci et al. (2007)], indicate that the required fluxes of both neutrons and photons can be achieved at ∼1 mA of 4-MeV deuterons. The goal of the proposed study is to confirm feasibility of the approach and develop requirements for future full- system implementation.

  10. Measurement of 1.7 to 74 MeV polarised gamma rays with the HARPO TPC

    CERN Document Server

    Geerebaert, Y; Amano, S; Attié, D; Bernard, D; Bruel, P; Calvet, D; Colas, P; Daté, S; Delbart, A; Frotin, M; Giebels, B; Götz, D; Hashimoto, S; Horan, D; Kotaka, T; Louzir, M; Minamiyama, Y; Miyamoto, S; Ohkuma, H; Poilleux, P; Semeniouk, I; Sizun, P; Takemoto, A; Yamaguchi, M; Wang, S

    2016-01-01

    Current {\\gamma}-ray telescopes based on photon conversions to electron-positron pairs, such as Fermi, use tungsten converters. They suffer of limited angular resolution at low energies, and their sensitivity drops below 1 GeV. The low multiple scattering in a gaseous detector gives access to higher angular resolution in the MeV-GeV range, and to the linear polarisation of the photons through the azimuthal angle of the electron-positron pair. HARPO is an R&D program to characterise the operation of a TPC (Time Projection Chamber) as a high angular-resolution and sensitivity telescope and polarimeter for {\\gamma} rays from cosmic sources. It represents a first step towards a future space instrument. A 30 cm cubic TPC demonstrator was built, and filled with 2 bar argon-based gas. It was put in a polarised {\\gamma}-ray beam at the NewSUBARU accelerator in Japan in November 2014. Data were taken at different photon energies from 1.7 MeV to 74 MeV, and with different polarisation configurations. The electronic...

  11. Dosimetric comparison of 4 MeV and 6 MeV electron beams for total skin irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung In; Park, So Yeon; Park, Jong Min; Ye, Sung Joon; Kim, Il Han [Dept. of Radiation Oncology, Seoul National University Hospital, Seoul (Korea, Republic of)

    2014-11-15

    Total skin electron irradiation (TSEI) was developed by Stanford University in the 1950s and introduced for the treatment of mycosis fungoides, the most common form of cutaneous T-cell lymphoma which generally affects the skin. In this study, dosimetric aspects of TSEI consisting of a 4 MeV beam with no spoiler were investigated in comparison to a nominal 6 MeV beam applications was evaluated. The suggested 4 MeV beam for TSEI could be applied to shallow depth skin diseases and to electron boost as second treatment course.

  12. Titanium-II: an evaluated nuclear data file. [E < 20. 0 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Philis, C.; Howerton, R.; Smith, A.B.

    1977-06-01

    A comprehensive evaluated nuclear data file for elemental titanium is outlined including definition of the data base, the evaluation procedures and judgments, and the final evaluated results. The file describes all significant neutron-induced reactions with elemental titanium and the associated photon-production processes to incident neutron energies of 20.0 MeV. In addition, isotopic-reaction files, consistent with the elemental file, are separately defined for those processes which are important to applied considerations of material-damage and neutron-dosimetry. The file is formulated in the ENDF format. This report formally documents the evaluation and, together with the numerical file, is submitted for consideration as a part of the ENDF/B-V evaluated file system. 20 figures, 9 tables.

  13. A detailed test of a BSO calorimeter with 100-800 MeV positrons

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, T., E-mail: ishikawa@lns.tohoku.ac.jp [Research Center for Electron Photon Science, Tohoku University, Sendai 982-0826 (Japan); Fujimura, H.; Hashimoto, R.; Kaida, S.; Kasagi, J.; Kitazawa, R.; Kuwasaki, S.; Nakamura, A.; Nawa, K.; Okada, Y.; Sato, M.; Shimizu, H.; Suzuki, K. [Research Center for Electron Photon Science, Tohoku University, Sendai 982-0826 (Japan); Tajima, Y. [Department of Physics, Yamagata University, Yamagata 990-8560 (Japan); Takahashi, S.; Tsuchikawa, Y.; Yamazaki, H. [Research Center for Electron Photon Science, Tohoku University, Sendai 982-0826 (Japan); Yoshida, H.Y. [Department of Physics, Yamagata University, Yamagata 990-8560 (Japan)

    2012-12-01

    A performance test has been made for an electro-magnetic calorimeter prototype comprised four identical BSO crystals arranged in a 2 Multiplication-Sign 2 matrix by utilizing a positron beam in the energy range from 100 to 800 MeV. The size of each crystal is 40 Multiplication-Sign 40 Multiplication-Sign 210 mm{sup 3}. This is the world's largest BSO single crystal ever used as a photon detector. The obtained energy resolution is ({sigma}{sub E}/E){sup 2}=((1.71%{+-}0.03%)/{radical}(E)){sup 2}+(1.12%{+-}0.08%){sup 2} at room temperature, where E is the incident positron energy given in GeV. A BGO calorimeter having the same geometry has been employed in the performance test for comparison. The basic scintillation characteristics of BSO crystals measured without the beam are also presented.

  14. An inelastic X-ray spectrometer with 2.2 meV energy resolution

    CERN Document Server

    Sinn, H; Alatas, A; Barraza, J; Bortel, G; Burkel, E; Shu, D; Sturhahn, W; Sutter, J P; Toellner, T S; Zhao, J

    2001-01-01

    We present a new spectrometer at the Advanced Photon Source for inelastic X-ray scattering with an energy resolution of 2.2 meV at an incident energy of 21.6 keV. For monochromatization, a nested structure of one silicon channel cut and one 'artificial' channel cut is used in forward-scattering geometry. The energy analysis is achieved by a two-dimensional focusing silicon analyzer in backscattering geometry. In the first demonstration experiments, elastic scattering from a Plexiglas sup T sup M sample and two dispersion curves in a beryllium single crystal were measured. Based on these data sets, the performance of the new spectrometer is discussed.

  15. Optomechanical photon shuttling between photonic cavities

    CERN Document Server

    Li, Huan

    2014-01-01

    Mechanical motion of photonic devices driven by optical forces provides a profound means of coupling between optical fields. The current focus of these optomechanical effects has been on cavity optomechanics systems in which co-localized optical and mechanical modes interact strongly to enable wave-mixing between photons and phonons and backaction cooling of mechanical modes. Alternatively, extended mechanical modes can also induce strong nonlocal effects on propagating optical fields or multiple localized optical modes at distances. Here, we demonstrate a novel multi-cavity optomechanical device: a "photon see-saw", in which torsional optomechanical motion can shuttle photons between two photonic crystal nanocavities. The resonance frequencies of the two cavities, one on each side of the see-saw, are modulated anti-symmetrically by the device's rotation. Pumping photons into one cavity excites optomechanical self-oscillation which strongly modulates the inter-cavity coupling and shuttles photons to the other...

  16. Optomechanical photon shuttling between photonic cavities.

    Science.gov (United States)

    Li, Huan; Li, Mo

    2014-11-01

    Mechanical motion of photonic devices driven by optical forces provides a profound means of coupling between optical fields. The current focus of these optomechanical effects has been on cavity optomechanics systems in which co-localized optical and mechanical modes interact strongly to enable wave mixing between photons and phonons, and backaction cooling of mechanical modes. Alternatively, extended mechanical modes can also induce strong non-local effects on propagating optical fields or multiple localized optical modes at distances. Here, we demonstrate a multicavity optomechanical device in which torsional optomechanical motion can shuttle photons between two photonic crystal nanocavities. The resonance frequencies of the two cavities, one on each side of this 'photon see-saw', are modulated antisymmetrically by the device's rotation. Pumping photons into one cavity excites optomechanical self-oscillation, which strongly modulates the inter-cavity coupling and shuttles photons to the other empty cavity during every oscillation cycle in a well-regulated fashion.

  17. Calibration of a gamma ray astronomy telescope in the 5-50 MeV energy range

    Energy Technology Data Exchange (ETDEWEB)

    Lavigne, J.M.; Niel, M.; Vedrenne, G.; Doulade, C.; Giordano, G. (Toulouse-3 Univ., 31 (France). Centre d' Etude Spatiale des Rayonnements); Agrinier, B.; Bonfand, E.; Andrejol, J.; Courtois, J.C.; Gorisse, M. (CEA Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France))

    1982-08-15

    The Agathe experiment is a 1 m/sup 2/ spark chamber sensitive in the 5-50 MeV energy range designed for use on a stratospheric balloon. The different methods used to determine the efficiency, angular resolution and energy are described. Efficiency calibrations are made in gamma ray beams at different energies. The results are verified by a Monte Carlo calculation then extended to higher energies. The photon energy is determined by calibrations in electron beams and in gamma ray beams; two methods are compared and discussed.

  18. Scalable Quantum Photonics with Single Color Centers in Silicon Carbide.

    Science.gov (United States)

    Radulaski, Marina; Widmann, Matthias; Niethammer, Matthias; Zhang, Jingyuan Linda; Lee, Sang-Yun; Rendler, Torsten; Lagoudakis, Konstantinos G; Son, Nguyen Tien; Janzén, Erik; Ohshima, Takeshi; Wrachtrup, Jörg; Vučković, Jelena

    2017-02-24

    Silicon carbide is a promising platform for single photon sources, quantum bits (qubits), and nanoscale sensors based on individual color centers. Toward this goal, we develop a scalable array of nanopillars incorporating single silicon vacancy centers in 4H-SiC, readily available for efficient interfacing with free-space objective and lensed-fibers. A commercially obtained substrate is irradiated with 2 MeV electron beams to create vacancies. Subsequent lithographic process forms 800 nm tall nanopillars with 400-1400 nm diameters. We obtain high collection efficiency of up to 22 kcounts/s optical saturation rates from a single silicon vacancy center while preserving the single photon emission and the optically induced electron-spin polarization properties. Our study demonstrates silicon carbide as a readily available platform for scalable quantum photonics architecture relying on single photon sources and qubits.

  19. Photon and photoneutron spectra produced in radiotherapy Linacs

    Energy Technology Data Exchange (ETDEWEB)

    Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Calle Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico); Martinez O, S. A. [Universidad Pedagogica y Tecnologica de Colombia, Grupo de Fisica Nuclear Aplicada y Simulacion, Av. Central del Norte Km. 1, Via Paipa Tunja, Boyaca (Colombia); Benites R, J. L. [Universidad Autonoma de Nayarit, Postgrado CBAP, Carretera Tepic Compostela Km. 9, Xalisco, Nayarit (Mexico); Lallena, A. M., E-mail: fermineutron@yahoo.com [Universida de Granada, Departamento de Fisica Atomica, Molecular y Nuclear, E-18071 Granada (Spain)

    2011-10-15

    A Monte Carlo calculation, using the MCNPX code, was carried out in order to estimate the photon and neutron spectra in two locations of two linacs operating at 15 and 18 MV. Detailed models of both linac heads were used in the calculations. Spectra were estimated below the flattening filter and at the isocenter. Neutron spectra show two components due to evaporation and knock-on neutrons. Lethargy spectra under the filter were compared to the spectra calculated from the function quoted by Tosi et al. that describes reasonably well neutron spectra beyond 1 MeV, though tends to underestimate the energy region between 10{sup -6} and 1 MeV. Neutron and Bremsstrahlung spectra show the same features regardless of the linac voltage. The amount of photons and neutrons produced by the 15 MV linac is smaller than that found for the 18 MV linac. As expected, Bremsstrahlung spectra ends according to the voltage used to accelerate the electrons. (Author)

  20. Low-power communication with a photonic heat pump.

    Science.gov (United States)

    Huang, Duanni; Santhanam, Parthiban; Ram, Rajeev J

    2014-12-15

    An optical communication channel is constructed using a heated thermo-electrically pumped, high efficiency infrared light-emitting diode (LED). In these devices, electro-luminescent cooling is observed, resulting in greater than unity (> 100%) efficiency in converting electrical power to optical power. The average amount of electrical energy required to generate a photon (4.3 meV) is much less than the optical energy in that photon (520 meV). Such a light source can serve as a test-bed for fundamental studies of energy-efficient bosonic communication channels. In this low energy consumption mode, we demonstrate data transmission at 3 kilobits per second (kbps) with only 120 picowatts of input electric power. Although the channel employs a mid-infrared source with limited quantum efficiency, a binary digit can be communicated using 40 femtojoules with a bit error rate of 3 x 10-3.

  1. Observation of high energy electromagnetic dipole radiation in /sup 14/N + Ni reactions at Esub(lab)/A = 35 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Alamanos, N.; Braun-Munzinger, P.; Freifelder, R.F.; Paul, P.; Stachel, J.; Awes, T.C.; Ferguson, R.L.; Obenshain, F.E.; Plasil, F.; Young, G.R.

    1986-06-19

    High energy photons (20 < Esub(..gamma..) < 150 MeV) produced in inclusive /sup 14/N+Ni->..gamma..+X reactions were unambiguously observed in a Pb-glass detector array. The measured angular distributions exhibit a predominant dipole pattern. This rules out statistical and/or nucleon-nucleon production mechanisms. The data indicate instead a more coherent production mechanism reflecting the direction of relative motion of target and projectile.

  2. Axion-like particle searches with sub-THz photons

    CERN Document Server

    Capparelli, L.; Ferretti, J.; Giazotto, F.; Polosa, A.D.; Spagnolo, P.

    2016-01-01

    We propose a variation, based on very low energy and extremely intense photon sources, on the well established technique of Light-Shining-through-Wall (LSW) experiments for axion-like particle searches. With radiation sources at 30 GHz, we compute that present laboratory exclusion limits on axion-like particles might be improved by at least four orders of magnitude, for masses m_a <~ 0.01~meV. This could motivate research and development programs on dedicated single-photon sub-THz detectors.

  3. Axion-like particle searches with sub-THz photons

    Science.gov (United States)

    Capparelli, L. M.; Cavoto, G.; Ferretti, J.; Giazotto, F.; Polosa, A. D.; Spagnolo, P.

    2016-06-01

    We propose a variation, based on very low energy and extremely intense photon sources, on the well established technique of Light-Shining-through-Wall (LSW) experiments for axion-like particle searches. With radiation sources at 30 GHz, we compute that present laboratory exclusion limits on axion-like particles might be improved by at least four orders of magnitude, for masses ma ≲ 0.01 meV. This could motivate research and development programs on dedicated single-photon sub-THz detectors.

  4. Two-Photon Total Annihilation of Molecular Positronium

    CERN Document Server

    Pérez-Ríos, Jesús; Greene, Chris H

    2014-01-01

    The rate for complete two-photon annihilation of molecular positronium Ps$_{2}$ is reported. This decay channel involves a four-body collision among the fermions forming Ps$_{2}$, and two photons of 1.022 MeV, each, as the final state. The quantum electrodynamics result for the rate of this process is found to be $\\Gamma_{Ps_{2} \\rightarrow \\gamma\\gamma}$ = 9.0 $\\times 10^{-12}$ s$^{-1}$. This decay channel completes the most comprehensive decay chart for Ps$_{2}$ up to date.

  5. Photon-Photon Collisions -- Past and Future

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, Stanley J.; /SLAC

    2005-12-02

    I give a brief review of the history of photon-photon physics and a survey of its potential at future electron-positron colliders. Exclusive hadron production processes in photon-photon and electron-photon collisions provide important tests of QCD at the amplitude level, particularly as measures of hadron distribution amplitudes. There are also important high energy {gamma}{gamma} and e{gamma} tests of quantum chromodynamics, including the production of jets in photon-photon collisions, deeply virtual Compton scattering on a photon target, and leading-twist single-spin asymmetries for a photon polarized normal to a production plane. Since photons couple directly to all fundamental fields carrying the electromagnetic current including leptons, quarks, W's and supersymmetric particles, high energy {gamma}{gamma} collisions will provide a comprehensive laboratory for Higgs production and exploring virtually every aspect of the Standard Model and its extensions. High energy back-scattered laser beams will thus greatly extend the range of physics of the International Linear Collider.

  6. In-medium modifications of the pi pi interaction in photon-induced reactions

    NARCIS (Netherlands)

    Messchendorp, JG; Janssen, S; Kotulla, M; Ahrens, J; Annand, JRH; Beck, R; Bloch, F; Caselotti, G; Fog, L; Hornidge, D; Krusche, B; Langgartner, W; McGeorge, JC; MacGregor, IJD; Mengel, K; Metag, V.; Novotny, R; Owens, RO; Pfeiffer, M; Sack, S; Sanderson, R.; Schadmand, S

    2002-01-01

    Differential cross sections of the reactions (gamma,pi(0)pi(0)) and (gamma,pi(0)pi(+/-)) have been measured for several nuclei (H-1,C-12, and Pb-nat) at an incident-photon energy of E-gamma=400-460 MeV at the tagged-photon facility at MAMI-B using the TAPS spectrometer. A significant nuclear-mass de

  7. Photonic Crystals Towards Nanoscale Photonic Devices

    CERN Document Server

    Lourtioz, Jean-Michel; Berger, Vincent; Gérard, Jean-Michel; Maystre, Daniel; Tchelnokov, Alexis

    2005-01-01

    Just like the periodical crystalline potential in solid-state crystals determines their properties for the conduction of electrons, the periodical structuring of photonic crystals leads to envisioning the possibility of achieving a control of the photon flux in dielectric and metallic materials. The use of photonic crystals as a cage for storing, filtering or guiding light at the wavelength scale thus paves the way to the realisation of optical and optoelectronic devices with ultimate properties and dimensions. This should contribute toward meeting the demands for a greater miniaturisation that the processing of an ever increasing number of data requires. Photonic Crystals intends at providing students and researchers from different fields with the theoretical background needed for modelling photonic crystals and their optical properties, while at the same time presenting the large variety of devices, from optics to microwaves, where photonic crystals have found applications. As such, it aims at building brid...

  8. Photonic Crystals Towards Nanoscale Photonic Devices

    CERN Document Server

    Lourtioz, Jean-Michel; Berger, Vincent; Gérard, Jean-Michel; Maystre, Daniel; Tchelnokov, Alexei; Pagnoux, Dominique

    2008-01-01

    Just like the periodical crystalline potential in solid state crystals determines their properties for the conduction of electrons, the periodical structuring of photonic crystals leads to envisioning the possibility of achieving a control of the photon flux in dielectric and metallic materials. The use of photonic crystals as cages for storing, filtering or guiding light at the wavelength scale paves the way to the realization of optical and optoelectronic devices with ultimate properties and dimensions. This will contribute towards meeting the demands for greater miniaturization imposed by the processing of an ever increasing number of data. Photonic Crystals will provide students and researchers from different fields with the theoretical background required for modelling photonic crystals and their optical properties, while at the same time presenting the large variety of devices, ranging from optics to microwaves, where photonic crystals have found application. As such, it aims at building bridges between...

  9. Photon-photon scattering: a tutorial

    CERN Document Server

    Liang, Yi

    2011-01-01

    Long-established results for the low-energy photon-photon scattering, gamma gamma --> gamma gamma, have recently been questioned. We analyze that claim and demonstrate that it is inconsistent with experience. We demonstrate that the mistake originates from an erroneous manipulation of divergent integrals and discuss the connection with another recent claim about the Higgs decay into two photons. We show a simple way of correctly computing the low-energy gamma gamma scattering.

  10. Azimuthal correlations in photon-photon collisions

    CERN Document Server

    Artéaga-Romero, N; Kessler, P; Ong, S; Panella, O

    1995-01-01

    Using the general helicity formula for \\gamma^* \\gamma^* collisions, we are showing that it should be possible to determine a number of independent ``structure functions'', i.e. linear combinations of elements of the two-photon helicity tensor, through azimuthal correlations in two-body or quasi two-body reactions induced by the photon-photon interaction, provided certain experimental conditions are satisfied. Numerical results of our computations are presented for some particular processes and dynamic models.

  11. Temporal Structure of MeV Electron Precipitation

    Science.gov (United States)

    Millan, R. M.; Lorentzen, K. R.; Lin, R. P.; Smith, D. M.

    2001-12-01

    On January 12, 2000, the MAXIS (MeV Auroral X-ray Imaging and Spectroscopy) long duration balloon experiment was launched from McMurdo, Antarctica carrying x-ray instrumentation designed to search for MeV electron precipitation similar to the event observed in 1996 over Kiruna, Sweden (L=5.8). MAXIS detected seven x-ray bursts with significant flux extending above 0.8 MeV during the 18 day flight in addition to extended periods of softer X-ray activity. These seven events are characterized by an extremely flat spectrum ( ~E-1.7) indicating that the bulk of precipitating electrons producing the x-rays is at relativistic energies. The bursts were detected between magnetic latitudes 58o-67o (corresponding to L-values between 3.8-6.7) with durations varying from several minutes to several hours. The MeV bursts were found to occur preferentially in the late afternoon/dusk sectors (14:30-00:00 MLT) while softer precipitation was detected at all magnetic local times. Two of the strongest MeV events detected by MAXIS show strong modulation of the x-ray count rate at ULF timescales ( ~150 s) similar to modulations observed during the Kiruna event at 100-200 s. We present results from temporal analysis of the MAXIS germanium spectrometer data and examine ground-based and spacecraft observations for evidence of coincident ULF wave activity.

  12. Field Flatness Tuning for PEFP 100 MeV DTL

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Han-Sung; Kwon, Hyeok-Jung; Seol, Kyung-Tae; Kim, Dae-Il; Cho, Yong-Sub [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2008-05-15

    A conventional 100 MeV drift tube linac is under development for Proton Engineering Frontier Project. Currently the proton linac up to 20 MeV, which consists of injector, 3 MeV RFQ and 20 MeV DTL is completed. To accelerate the proton beam up to 100 MeV additional 7 DTL tanks are required. The DTL should be tuned after fabrication and alignment of the drift tube inside the tank to meet the requirements from the beam dynamics. Tuning process includes the resonant frequency tuning, field flatness tuning and tilt sensitivity tuning. The tuning goal for the field flatness tuning is less than {+-}2% in field uniformity throughout the DTL tank with less than {+-}% standard deviation. A non-uniform field profile caused by the machining errors and alignment errors can be made uniform through the slug tuner adjustment. This procedure requires the field profile measurements and several iterations between the field profile measurements and adjustment. The methods and the results of the DTL field flatness tuning will be reported in this presentation.

  13. The RBE of 3.4 MeV alpha-particles and 0.565 MeV neutrons relative to 60Co gamma-rays for neoplastic transformation of human hybrid cells and the impact of culture conditions.

    Science.gov (United States)

    Frankenberg-Schwager, M; Spieren, S; Pralle, E; Giesen, U; Brede, H J; Thiemig, M; Frankenberg, D

    2010-01-01

    The neoplastic transformation of human hybrid CGL1 cells is affected by perturbations from external influences such as serum batch and concentration, the number of medium changes during the 21-day expression period and cell seeding density. Nevertheless, for doses up to 1.5 Gy, published transformation frequencies for low linear energy transfer (LET) radiations (gamma-rays, MeV electrons or photons) are in good agreement, whereas for higher doses larger variations are reported. The (60)Co gamma-ray data here for doses up to 1.5 Gy, using a low-yield serum batch and only one medium change, are in agreement with published frequencies of neoplastic transformation of human hybrid cells. For 3.4 MeV alpha-particles (LET = 124 keV/mum) and 0.565 MeV monoenergetic neutrons relative to low doses of (60)Co gamma-rays, a maximum relative biological effectiveness (RBE(M)) of 2.8 +/- 0.2 and 1.5 +/- 0.2, respectively, was calculated. Surprisingly, at higher doses of (60)Co gamma-rays lower frequencies of neoplastic transformation were observed. This non-monotonic dose relationship for neoplastic transformation by (60)Co gamma-rays is likely due to the lack of a G2/M arrest observed at low doses resulting in higher transformation frequencies per dose, whereas the lower frequencies per dose observed for higher doses are likely related to the induction of a G2/M arrest.

  14. Multi-photon creation and single-photon annihilation of electron-positron pairs

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Huayu

    2011-04-27

    In this thesis we study multi-photon e{sup +}e{sup -} pair production in a trident process, and singlephoton e{sup +}e{sup -} pair annihilation in a triple interaction. The pair production is considered in the collision of a relativistic electron with a strong laser beam, and calculated within the theory of laser-dressed quantum electrodynamics. A regularization method is developed systematically for the resonance problem arising in the multi-photon process. Total production rates, positron spectra, and relative contributions of different reaction channels are obtained in various interaction regimes. Our calculation shows good agreement with existing experimental data from SLAC, and adds further insights into the experimental findings. Besides, we study the process in a manifestly nonperturbative domain, whose accessibility to future all-optical experiments based on laser acceleration is shown. In the single-photon e{sup +}e{sup -} pair annihilation, the recoil momentum is absorbed by a spectator particle. Various kinematic configurations of the three incoming particles are examined. Under certain conditions, the emitted photon exhibits distinct angular and polarization distributions which could facilitate the detection of the process. Considering an equilibrium relativistic e{sup +}e{sup -} plasma, it is found that the single-photon process becomes the dominant annihilation channel for plasma temperatures above 3 MeV. Multi-particle correlation effects are therefore essential for the e{sup +}e{sup -} dynamics at very high density. (orig.)

  15. 3 MeV Test Stand commissioning report

    CERN Document Server

    Bellodi, Guilia; Andreassen, O; Comblin, J-F; Dimov, V; Lallement, J-B; Martin, C; Midttun, O; Ovalle, E; Raich, U; Roncarolo, F; Rossi, C; Scrivens, R; Vollaire, J; Yarmohammadi Satri, M; Zocca, Z

    2013-01-01

    Linac4 is a normal-conducting 160 MeV H- linear accelerator, presently under construction, that will replace the present 50 MeV Linac2 as injector of the CERN proton accelerator complex with the goal of increasing the LHC luminosity. The Linac4 front-end, composed of a 45 keV ion source, a Low Energy Beam Transport (LEBT), a 352.2 MHz Radio Frequency Quadrupole (RFQ) and a Medium Energy Beam Transport (MEBT) housing a beam chopper, was commissioned at the 3 MeV test stand area during the first half of 2013. This report gives details of the installation and operational systems used, describes the commissioning phases and measurements performed and summarizes the results that were finally achieved and the lessons learnt in the process.

  16. 400-MeV upgrade for the Fermilab linac

    Energy Technology Data Exchange (ETDEWEB)

    Young, D.E.; Noble, R.J.

    1989-09-01

    Fermilab plans to upgrade the Tevatron to expand the physics research program in both the fixed target and the collider operating modes. The first phase of this program is to increase the energy of the H{sup -} linac from 200 to 400 MeV in order to reduce the incoherent space change tuneshift at injection into the Booster which can limit either the brightness or the total intensity of the beam. The linac upgrade will be achieved by replacing the last four 201 MeV, with seven 805 MHz side-coupled cavity modules operating at an average axial field of about 8 MV/m. This will allow acceleration to 400 MeV in the existing Linac enclosure. 4 refs., 3 figs., 1 tab.

  17. Resolution considerations in MeV ion microscopy and lithography

    Energy Technology Data Exchange (ETDEWEB)

    Norarat, Rattanaporn, E-mail: rattanaporn@rmutl.ac.th [University of Applied Sciences (HES-SO), Haute Ecole Arc Ingénierie, Eplatures-Gris 17, CH-2300 La Chaux-de-Fonds (Switzerland); Faculty of Sciences and Agricultural Technology, Rajamangala University of Technology Lanna, Chiang Rai, 57120 Chiang Rai (Thailand); Whitlow, Harry J. [University of Applied Sciences (HES-SO), Haute Ecole Arc Ingénierie, Eplatures-Gris 17, CH-2300 La Chaux-de-Fonds (Switzerland)

    2015-04-01

    There a disparity between the way the resolution is specified in microscopy and lithography using light compared to MeV ion microscopy and lithography. In this work we explore the implications of the way the resolution is defined with a view to answering the questions; how are the resolving powers in MeV ion microscopy and lithography relate to their optical counterparts? and how do different forms of point spread function affect the modulation transfer function and the sharpness of the edge profile?.

  18. Lifetime of 19Ne*(4.03 MeV)

    CERN Document Server

    Kanungo, R; Andreyev, A N; Ball, G C; Chakravarthy, R S; Chicoine, M; Churchman, R; Davids, B; Forster, J S; Gujrathi, S; Hackman, G; Howell, D; Leslie, J R; Morton, A C; Mythili, S; Pearson, C J; Ressler, J J; Ruiz, C; Savajols, H; Schumaker, M A; Tanihata, I; Walden, P L; Yen, S

    2006-01-01

    The Doppler-shift attenuation method was applied to measure the lifetime of the 4.03 MeV state in 19Ne. Utilizing a 3He-implanted Au foil as a target, the state was populated using the 20Ne(3He,alpha)19Ne reaction in inverse kinematics at a 20Ne beam energy of 34 MeV. De-excitation gamma rays were detected in coincidence with alpha particles. At the 1 sigma level, the lifetime was determined to be 11 +4, -3 fs and at the 95.45% confidence level the lifetime is 11 +8, -7 fs.

  19. The effect of biological shielding on fast neutron and photon transport in the VVER-1000 mock-up model placed in the LR-0 reactor.

    Science.gov (United States)

    Košťál, Michal; Cvachovec, František; Milčák, Ján; Mravec, Filip

    2013-05-01

    The paper is intended to show the effect of a biological shielding simulator on fast neutron and photon transport in its vicinity. The fast neutron and photon fluxes were measured by means of scintillation spectroscopy using a 45×45 mm(2) and a 10×10 mm(2) cylindrical stilbene detector. The neutron spectrum was measured in the range of 0.6-10 MeV and the photon spectrum in 0.2-9 MeV. The results of the experiment are compared with calculations. The calculations were performed with various nuclear data libraries.

  20. High energy photon-photon collisions

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, S.J. [Stanford Linear Accelerator Center, Menlo Park, CA (United States); Zerwas, P.M. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    1994-07-01

    The collisions of high energy photons produced at a electron-positron collider provide a comprehensive laboratory for testing QCD, electroweak interactions and extensions of the standard model. The luminosity and energy of the colliding photons produced by back-scattering laser beams is expected to be comparable to that of the primary e{sup +}e{sup {minus}} collisions. In this overview, we shall focus on tests of electroweak theory in photon-photon annihilation, particularly {gamma}{gamma} {yields} W{sup +}W{sup {minus}}, {gamma}{gamma} {yields} Higgs bosons, and higher-order loop processes, such as {gamma}{gamma} {yields} {gamma}{gamma}, Z{gamma} and ZZ. Since each photon can be resolved into a W{sup +}W{sup minus} pair, high energy photon-photon collisions can also provide a remarkably background-free laboratory for studying WW collisions and annihilation. We also review high energy {gamma}{gamma} tests of quantum chromodynamics, such as the scaling of the photon structure function, t{bar t} production, mini-jet processes, and diffractive reactions.

  1. Simulating single photons with realistic photon sources

    Science.gov (United States)

    Yuan, Xiao; Zhang, Zhen; Lütkenhaus, Norbert; Ma, Xiongfeng

    2016-12-01

    Quantum information processing provides remarkable advantages over its classical counterpart. Quantum optical systems have been proved to be sufficient for realizing general quantum tasks, which, however, often rely on single-photon sources. In practice, imperfect single-photon sources, such as a weak-coherent-state source, are used instead, which will inevitably limit the power in demonstrating quantum effects. For instance, with imperfect photon sources, the key rate of the Bennett-Brassard 1984 (BB84) quantum key distribution protocol will be very low, which fortunately can be resolved by utilizing the decoy-state method. As a generalization, we investigate an efficient way to simulate single photons with imperfect ones to an arbitrary desired accuracy when the number of photonic inputs is small. Based on this simulator, we can thus replace the tasks that involve only a few single-photon inputs with the ones that make use of only imperfect photon sources. In addition, our method also provides a quantum simulator to quantum computation based on quantum optics. In the main context, we take a phase-randomized coherent state as an example for analysis. A general photon source applies similarly and may provide some further advantages for certain tasks.

  2. Dosimeter configurations for the measurement of Hs(0.07) and Hp(10) from photons

    DEFF Research Database (Denmark)

    Christensen, P.; Bøtter-Jensen, L.; Ennow, K.

    1990-01-01

    The optimisation is discussed of filter/detector configurations of dosemeters for individual monitoring for photons in the energy range from 20 keV to 1.3 MeV. Experimental data are given on energy and angular responses of dosemeters with different combinations of aluminium and plastic filters. Li...

  3. Photon and proton induced fission on heavy nuclei at intermediate energies

    Directory of Open Access Journals (Sweden)

    Andrade-II E.

    2014-04-01

    Full Text Available We present an analysis of fission induced by intermediate energy protons or photons on actinides. The 660 MeV proton induced reactions are on 241Am, 238U, and 237Np targets and the Bremmstrahlung-photons with end-point energies at 50 MeV and 3500 MeV are on 232Th and 238U targets. The study was performed by means of the Monte Carlo simulation code CRISP. A multimodal fission extension was added to the code within an approach which accounts for the contribution of symmetric and asymmetric fission. This procedure allowed the investigation of fission cross sections, fissility, number of evaporated nucleons and fission-fragment charge distributions. The comparison with experimental data show a good agreement between calculations and experiments.

  4. Photonic Design for Photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Kosten, E.; Callahan, D.; Horowitz, K.; Pala, R.; Atwater, H.

    2014-08-28

    We describe photonic design approaches for silicon photovoltaics including i) trapezoidal broadband light trapping structures ii) broadband light trapping with photonic crystal superlattices iii) III-V/Si nanowire arrays designed for broadband light trapping.

  5. Composite Photon Theory Versus Elementary Photon Theory

    CERN Document Server

    Perkins, Walton A

    2015-01-01

    The purpose of this paper is to show that the composite photon theory measures up well against the Standard Model's elementary photon theory. This is done by comparing the two theories area by area. Although the predictions of quantum electrodynamics are in excellent agreement with experiment (as in the anomalous magnetic moment of the electron), there are some problems, such as the difficulty in describing the electromagnetic field with the four-component vector potential because the photon has only two polarization states. In most areas the two theories give similar results, so it is impossible to rule out the composite photon theory. Pryce's arguments in 1938 against a composite photon theory are shown to be invalid or irrelevant. Recently, it has been realized that in the composite theory the antiphoton does not interact with matter because it is formed of a neutrino and an antineutrino with the wrong helicity. This leads to experimental tests that can determine which theory is correct.

  6. Photonic crystal fibers

    DEFF Research Database (Denmark)

    Lægsgaard, Jesper; Hansen, K P; Nielsen, M D;

    2003-01-01

    Photonic crystal fibers having a complex microstructure in the transverse plane constitute a new and promising class of optical fibers. Such fibers can either guide light through total internal reflection or the photonic bandgap effect, In this paper, we review the different types and applications...... of photonic crystal fibers with particular emphasis on recent advances in the field....

  7. Diffusion Based Photon Mapping

    DEFF Research Database (Denmark)

    Schjøth, Lars; Olsen, Ole Fogh; Sporring, Jon

    2006-01-01

    . To address this problem we introduce a novel photon mapping algorithm based on nonlinear anisotropic diffusion. Our algorithm adapts according to the structure of the photon map such that smoothing occurs along edges and structures and not across. In this way we preserve the important illumination features......, while eliminating noise. We call our method diffusion based photon mapping....

  8. Diffusion Based Photon Mapping

    DEFF Research Database (Denmark)

    Schjøth, Lars; Fogh Olsen, Ole; Sporring, Jon

    2007-01-01

    . To address this problem we introduce a novel photon mapping algorithm based on nonlinear anisotropic diffusion. Our algorithm adapts according to the structure of the photon map such that smoothing occurs along edges and structures and not across. In this way we preserve the important illumination features......, while eliminating noise. We call our method diffusion based photon mapping....

  9. GAMMA-RAY OBSERVATIONS OF CYGNUS X-1 ABOVE 100 MeV IN THE HARD AND SOFT STATES

    Energy Technology Data Exchange (ETDEWEB)

    Sabatini, S.; Tavani, M.; Del Santo, M.; Campana, R.; Evangelista, Y.; Piano, G.; Del Monte, E.; Giusti, M.; Striani, E. [INAF/IAPS-Roma, I-00133 Roma (Italy); Coppi, P. [Yale University, P.O. Box 208101, New Haven, CT 06520-8101 (United States); Pooley, G. [Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE (United Kingdom); Chen, A.; Giuliani, A. [INAF/IASF-Milano, I-20133 Milano (Italy); Bulgarelli, A. [INAF/IASF-Bologna, I-40129 Bologna (Italy); Cattaneo, P. W. [INFN-Pavia, I-27100 Pavia (Italy); Colafrancesco, S. [INAF-OAR, I-00040 Monteporzio Catone (Italy); Longo, F. [Dip. Fisica and INFN Trieste, I-34127 Trieste (Italy); Morselli, A. [INFN Roma Tor Vergata, I-00133 Roma (Italy); Pellizzoni, A. [INAF-OAC, I-09012 Capoterra (Italy); Pilia, M. [ASTRON, The Netherlands Institute for Radio Astronomy, Postbus 2, 7990 AA, Dwingeloo (Netherlands); and others

    2013-04-01

    We present the results of multi-year gamma-ray observations by the AGILE satellite of the black hole binary system Cygnus X-1. In a previous investigation we focused on gamma-ray observations of Cygnus X-1 in the hard state during the period mid-2007/2009. Here we present the results of the gamma-ray monitoring of Cygnus X-1 during the period 2010/mid-2012 which includes a remarkably prolonged 'soft state' phase (2010 June-2011 May). Previous 1-10 MeV observations of Cyg X-1 in this state hinted at a possible existence of a non-thermal particle component with substantial modifications of the Comptonized emission from the inner accretion disk. Our AGILE data, averaged over the mid-2010/mid-2011 soft state of Cygnus X-1, provide a significant upper limit for gamma-ray emission above 100 MeV of F{sub soft} < 20 Multiplication-Sign 10{sup -8} photons cm{sup -2} s{sup -1} , excluding the existence of prominent non-thermal emission above 100 MeV during the soft state of Cygnus X-1. We discuss theoretical implications of our findings in the context of high-energy emission models of black hole accretion. We also discuss possible gamma-ray flares detected by AGILE. In addition to a previously reported episode observed by AGILE in 2009 October during the hard state, we report a weak but important candidate for enhanced emission which occurred at the end of 2010 June (2010 June 30 10:00-2010 July 2 10:00 UT) exactly coinciding with a hard-to-soft state transition and before an anomalous radio flare. An appendix summarizes all previous high-energy observations and possible detections of Cygnus X-1 above 1 MeV.

  10. Ultrafast photonic crystal optical switching

    Institute of Scientific and Technical Information of China (English)

    GONG Qi-huang; HU Xiao-yong

    2006-01-01

    Photonic crystal,a novel and artificial photonic material with periodic dielectric distribution,possesses photonic bandgap and can control the propagation states of photons.Photonic crystal has been considered to be a promising candidate for the future integrated photonic devices.The properties and the fabrication method of photonic crystal are expounded.The progresses of the study of ultrafast photonic crystal optical switching are discussed in detail.

  11. Linac4 crosses the 100 MeV threshold

    CERN Multimedia

    Corinne Pralavorio

    2016-01-01

    The new linear accelerator, which from 2020 will be the first link in the accelerator chain, has entered a new stage of its commissioning.   Members of the team in charge of the commissioning of Linac4 in the accelerator’s control room. A few hours earlier, Linac4 accelerated a beam to 107 MeV for the first time. We couldn’t have imagined a more appropriate date: on 1 July (1.07), Linac4 reached an energy of 107 MeV. Having crossed the 100 MeV barrier, the linear accelerator is now on the home straight of its commissioning. “This stage was very quick – it took less than two weeks,” says Alessandra Lombardi, deputy project leader of Linac4, in charge of the commissioning. In 2020, Linac4 will replace the existing Linac2 as the first link in the accelerator chain. It will accelerate beams of H- ions (protons surrounded by two electrons) to 160 MeV, compared to 50 MeV with Linac2. The new machine is particularly sophisticated as it comprises...

  12. History of the ZGS 500 MeV booster.

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, J.; Martin; R.; Kustom, R.

    2006-05-09

    The history of the design and construction of the Argonne 500 MeV booster proton synchrotron from 1969 to 1982 is described. This accelerator has since been in steady use for the past 25 years to power the Argonne Intense Pulsed Neutron Source (IPNS).

  13. Hadron production in photon-photon processes at the ILC

    Energy Technology Data Exchange (ETDEWEB)

    Sasikumar, Kollassery Swathi [Deutsches Elektronen-Synchrotron (DESY), Notkestrasse 85, 22607 Hamburg (Germany); Universitaet Hamburg, Institut fuer Experimentalphysik, Luruper Chaussee 149, 22761 Hamburg (Germany); Berggren, Carl Mikael; List, Jenny [Deutsches Elektronen-Synchrotron (DESY), Notkestrasse 85, 22607 Hamburg (Germany)

    2016-07-01

    The International linear Collider (ILC) is a proposed e{sup +}e{sup -} collider, designed to operate at energies from 91 GeV upto about 500 GeV (with the possibility to upgrade to 1 TeV). The highly clean conditions provided by the ILC enables us to make high precision measurements e.g. of the Higgs boson and to search for new particles. In addition to the desired e{sup +}e{sup -} collisions, parasitic collisions of real and virtual photons radiated off the e{sup ±} beams occur at rates of a few γγ collisions per bunch crossing. The γγ centre of mass energies reach from few 100 MeV up to the full e{sup +}e{sup -} centre of mass energy. For all these energies, in particular the production of hadrons,needs to be modelled correctly in order to estimate the impact of these backgrounds which pile-up on each e{sup +}e{sup -} event. This contribution discusses the current simulations of γγ → hadron processes, evaluates their impact on the detector and introduces new methods to remove them from the interesting physics events.

  14. Solar Hidden Photon Search

    CERN Document Server

    Schwarz, Matthias; Redondo, Javier; Ringwald, Andreas; Wiedemann, Guenter

    2011-01-01

    The Solar Hidden Photon Search (SHIPS) is a joint astroparticle project of the Hamburger Sternwarte and DESY. The main target is to detect the solar emission of a new species of particles, so called Hidden Photons (HPs). Due to kinetic mixing, photons and HPs can convert into each other as they propagate. A small number of solar HPs - originating from photon to HP oscillations in the interior of the Sun - can be converted into photons in a long vacuum pipe pointing to the Sun - the SHIPS helioscope.

  15. Solar Hidden Photon Search

    Energy Technology Data Exchange (ETDEWEB)

    Schwarz, Matthias; Wiedemann, Guenter [Hamburg Univ. (Germany). Sternwarte; Lindner, Axel; Ringwald, Andreas [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Redondo, Javier [Max-Planck-Institut fuer Physik und Astrophysik, Muenchen (Germany)

    2011-11-15

    The Solar Hidden Photon Search (SHIPS) is a joint astroparticle project of the Hamburger Sternwarte and DESY. The main target is to detect the solar emission of a new species of particles, so called Hidden Photons (HPs). Due to kinetic mixing, photons and HPs can convert into each other as they propagate. A small number of solar HPs - originating from photon to HP oscillations in the interior of the Sun - can be converted into photons in a long vacuum pipe pointing to the Sun - the SHIPS helioscope. (orig.)

  16. Dark photons in the Dalitz-like decay of a scalar

    CERN Document Server

    Kozlov, G A

    2016-01-01

    The couplings of the Standard Model sector to the scale invariant degrees of freedom can open the possibility to study dark photons (DP). The Dalitz-like decay of the (Higgs-like) scalar boson into a single photon and DP is studied. The interaction between DP and quarks is mediated by the derivative of the scalar field - the dilaton, the virtual (fictitious) state. The mass of the dilaton does not enter the final solutions. Upper limits are set on the DP mass, the mixing strength between the standard photon and DP. The model does allow to estimate the DP mass with the value of 4.5 MeV.

  17. Constraints on the photon charge based on observations of extragalactic sources

    CERN Document Server

    Kobychev, V V

    2004-01-01

    Using modern high-resolution observations of extragalactic compact radio sources we obtain an estimate of the upper bound on a photon electric charge at the level $e_{\\gamma} \\lesssim 3 \\cdot 10^{-33}$ of elementary charge (assuming the photon charge to be energy independent). This is three orders of magnitude better than the limit obtained with radio pulsar timing. Also we set a limit on a photon charge in the gamma-ray band (energies about 0.1 MeV). In future the estimate made for extragalactic sources can be significantly improved.

  18. Aspherical photon and anti-photon surfaces

    Directory of Open Access Journals (Sweden)

    G.W. Gibbons

    2016-12-01

    Full Text Available In this note we identify photon surfaces and anti-photon surfaces in some physically interesting spacetimes, which are not spherically symmetric. All of our examples solve physically reasonable field equations, including for some cases the vacuum Einstein equations, albeit they are not asymptotically flat. Our examples include the vacuum C-metric, the Melvin solution of Einstein–Maxwell theory and generalisations including dilaton fields. The (anti-photon surfaces are not round spheres, and the lapse function is not always constant.

  19. Neuromorphic Silicon Photonics

    CERN Document Server

    Tait, Alexander N; de Lima, Thomas Ferreira; Wu, Allie X; Nahmias, Mitchell A; Shastri, Bhavin J; Prucnal, Paul R

    2016-01-01

    We report first observations of an integrated analog photonic network, in which connections are configured by microring weight banks, as well as the first use of electro-optic modulators as photonic neurons. A mathematical isomorphism between the silicon photonic circuit and a continuous neural model is demonstrated through dynamical bifurcation analysis. Exploiting this isomorphism, existing neural engineering tools can be adapted to silicon photonic information processing systems. A 49-node silicon photonic neural network programmed using a "neural compiler" is simulated and predicted to outperform a conventional approach 1,960-fold in a toy differential system emulation task. Photonic neural networks leveraging silicon photonic platforms could access new regimes of ultrafast information processing for radio, control, and scientific computing.

  20. Active Photonic Crystal Waveguides

    DEFF Research Database (Denmark)

    Ek, Sara

    This thesis deals with the fabrication and characterization of active photonic crystal waveguides, realized in III-V semiconductor material with embedded active layers. The platform offering active photonic crystal waveguides has many potential applications. One of these is a compact photonic...... crystal semiconductor optical amplier. As a step towards such a component, photonic crystal waveguides with a single quantum well, 10 quantum wells and three layers of quantum dots are fabricated and characterized. An experimental study of the amplied spontaneous emission and a implied transmission...... due to photonic crystal dispersion. The observations are explained by the enhancement of net gain by light slow down. Another application based on active photonic crystal waveguides is micro lasers. Measurements on quantum dot micro laser cavities with different mirror configurations and photonic...

  1. Precise measurement of prompt photon emission for carbon ion therapy

    CERN Document Server

    Agodi, C; Cirrone, G A P; Collamati, F; Cuttone, G; De Lucia, E; De Napoli, M; Di Domenico, A; Faccini, R; Ferroni, F; Fiore, S; Gauzzi, P; Iarocci, E; Marafini, M; Mattei, I; Paoloni, A; Patera, V; Piersanti, L; Romano, F; Sarti, A; Sciubba, A; Voena, C

    2011-01-01

    Proton and carbon ion therapy is an emerging technique used for the treatment of solid cancers. The monitoring of the dose delivered during such treatments is still a matter of research. A possible technique exploits the information provided by single photon emission from nuclear decays induced by the irradiation. This paper reports the measurements of the spectrum and rate of such photons produced from the interaction of a 80 MeV/u fully stripped carbon ion beam at the Laboratori Nazionali del Sud of INFN, Catania, with a Poly-methyl methacrylate target. The differential production rate for photons with energy E > 2 MeV and emitted at 90 degree is found to be $dN_{\\gamma}/(dN_C d\\Omega)=(2.92\\pm 0.19)\\times 10^{-2}$sr$^{-1}$.

  2. Photoneutron source based on a compact 10 MeV betatron

    Energy Technology Data Exchange (ETDEWEB)

    Chakhlov, V.L. [Institute of Introscopy, Tomsk Polytechnic University, Tomsk 634028 (Russian Federation); Bell, Z.W. [Lockheed Martin Energy Systems, Inc., Oak Ridge, TN 37831 (United States); Golovkov, V.M. [Institute of Nuclear Physics, Tomsk Polytechnic University, Tomsk 634050 (Russian Federation); Shtein, M.M. [Institute of Introscopy, Tomsk Polytechnic University, Tomsk 634028 (Russian Federation)

    1999-02-11

    Accelerator-based photoneutron sources have enjoyed wide use and offer the advantages of long term stability, ease of control and absence of radioactive materials. We report here measurements of the yield of photoneutrons from a neutron generator using a compact betatron. Electrons were accelerated to energies up to 10 MeV and produced a bremsstrahlung beam with a dose rate of 0.16 Gy/min (at 10 MeV, 1 m from the bremsstrahlung target) to irradiate LiD, Be, depleted U, and Pb neutron-producing targets. The angular distributions of photoneutrons produced by bremsstrahlung beams were measured with a 'long' counter and integrated to determine neutron yield. In addition, neutron time of flight spectra were recorded from all targets using a 15.5 m flight path perpendicular to the photon beam. The maximum observed yields were 4.6x10{sup 7} n/s obtained with 1 kg of LiD, 5.7x10{sup 7} n/s from a 3.3 kg Be block, 6.2x10{sup 6} n/s from 1.5 kg of depleted U, and 7.0x10{sup 6} n/s from 10.7 kg of Pb. Optimization of target dimensions, shape, and positioning is expected to increase the yield from the LiD target by a factor of 35, while optimization of the other targets is expected to yield at most a factor of 10. With the increased yield and a deuteride target, this compact betatron-based system could find application in the interrogation of waste containers for fissile material.

  3. Narrow bandwidth Thomson photon source development using Laser-Plasma Accelerators

    Science.gov (United States)

    Geddes, C. G. R.; van Tilborg, J.; Tsai, H.-E.; Toth, Cs.; Vay, J.-L.; Lehe, R.; Schroeder, C. B.; Esarey, E.; Rykovanov, S. G.; Grote, D. P.; Friedman, A.; Leemans, W. P.

    2016-10-01

    Compact, high-quality photon sources at MeV energies are being developed based on Laser-Plasma Accelerators (LPAs). An independent scattering laser with controlled pulse shaping in frequency and amplitude can be used together with laser guiding to realize high photon yield and narrow bandwidth. Simulations are presented on production of controllable narrow bandwidth sources using the beam and plasma capabilities of LPAs. Recent experiments and simulations demonstrate controllable LPAs in the energy range appropriate to MeV Thomson sources. Design of experiments and laser capabilities to combine these elements will be presented, towards a compact photon source system. A dedicated facility under construction will be described. Work supported by US DOE NNSA DNN R&D and by Sc. HEP under contract DE-AC02-05CH11231.

  4. Thermoluminescent analyses of mean photon energy of a field

    Energy Technology Data Exchange (ETDEWEB)

    Cavalieri, T. A.; De Paiva, F.; Fonseca, G.; Dalledone S, P. de T.; Yoriyaz, H., E-mail: tassio.cavalieri@usp.br [Instituto de Pesquisas Energeticas e Nucleares / CNEN, Av. Lineu Prestes 2242, Cidade Universitaria, 05508-000 Sao Paulo (Brazil)

    2014-08-15

    Nowadays a common method of dosimetry is utilize the thermoluminescent dosimetry (TLD) of LiF, where for pure gamma field is typically used the LiF or CaF{sub 2} TLDs and for mixed neutron and gamma field dosimetry is used the pair TLD-600/TLD-700. The difference between these three LiF TLDs is the amount of isotope {sup 6}Li in their composition. The isotope {sup 6}Li has a great cross section for thermal neutrons, making the TLD-600 sensitive to thermal neutrons beyond the radiation gamma. Whereas the TLD-700 is considered sensitive only for radiation gamma. Some studies showed an energetic dependence of these TLDs for gammas rays. So the goal of this work was study these energetic dependence of TLDs from the angular coefficient of their response versus dose calibration curves when they were irradiated in four fields with photons of different energies: 43 keV, 662 keV, 1.2 MeV, 3 MeV. In order to create the calibration curves TLD, it was performed three irradiations with distinct exposure times for each photon energy. These studies showed a different angular coefficient to each curve; demonstrate the energetic dependence of these TLDs. By simulation with Monte Carlo based code, MCNP-5, it was observed the deposited photon dose due to different photons energies. From these simulations, it was also possible to observe a difference of dose deposition in TLDs when they were exposed to the same dose provided from different photons energies. These work showed the previously study of photon energetic dependence of LiF TLDs. (Author)

  5. Photon transport in binary photonic lattices

    OpenAIRE

    Rodríguez-Lara, B. M.; Moya-Cessa, H.

    2013-01-01

    We present a review on the mathematical methods used to theoretically study classical propagation and quantum transport in arrays of coupled photonic waveguides. We focus on analysing two types of binary photonic lattices where self-energies or couplings are alternated. For didactic reasons, we split the analysis in classical propagation and quantum transport but all methods can be implemented, mutatis mutandis, in any given case. On the classical side, we use coupled mode theory and present ...

  6. Photonic Crystal Fiber Based Entangled Photon Sources

    Science.gov (United States)

    2014-03-01

    new entanglement source is to make sure the source can provide an efficient and scalable quantum information processor . They are usually generated...multiple scattering on the telecom wavelength photon-pair. Our findings show that quantum correlation of polarization-entangled photon-pairs is...Fiber, Quantum communication, Keyed Communication in Quantum Noise (KCQ) 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT UU 18

  7. A method for simulating photon transport through matter

    Directory of Open Access Journals (Sweden)

    M. H. Alamatsaz

    1998-04-01

    Full Text Available   Monte Carlo simulation is widely used in calculations involing transport of photons through different materials of different shapes. The method consists of randomly generating a finite set of photon histories over which the quantities of interest are averaged. In photon transport calculations, sampling the photon scattering angle from the Klein-Nishina probability distribution is of special importance. Various methods of sampling the Klein-Nishina distribution exist in the literature which are mainly based either on approximate inverse sampling or non-uniform rejection sampling methods. A direct sampling method also exists which can only be used if the incident photon energy is greater than 1.4 MeV. In this work a weighting method for considering the Klein-Nishina distribution for the scanttering angle is presented, which is more accurate and faster than all other existing methods and is applicable for all incident photon energies. In this method an angle θ (0≤ θ ≤ Π is randomly generated at each scattering point and a weight W, which is proportional to the Klein-Nishina function at the generated , is calculated, and each event is weighted by the amount W. Events with multiple interactions are weghted by multiplication of the weights obtained at each scattering point. Using this method, the photon absorbed fraction , which is simply the fraction of the emitted photon energy that is absorbed in the region of interest, was calculated for central point sources in water spheres of different dimensions, and the results were compared with the results obtained by other methods. The consistency of the results shows that the weighting method presented here can efficiently be used in photon transport calculations.

  8. Characterization of PARIS LaBr$_3$(Ce)-NaI(Tl) phoswich detectors upto $E_\\gamma$ $\\sim$ 22 MeV

    CERN Document Server

    Ghosh, C; Pillay, R G; K., Anoop; Dokania, N; Pal, Sanjoy; Pose, M S; Mishra, G; Rout, P C; Kumar, Suresh; Pandit, Deepak; Mondal, Debasish; Pal, Surajit; Banerjee, S R; Napiorkowski, Paweł J; Dorvaux, Oliver; Kihel, S; Mathieu, C; Maj, A

    2016-01-01

    In order to understand the performance of the PARIS (Photon Array for the studies with Radioactive Ion and Stable beams) detector, detailed characterization of two individual phoswich (LaBr$_3$(Ce)-NaI(Tl)) elements has been carried out. The detector response is investigated over a wide range of $E_{\\gamma}$ = 0.6 to 22.6 MeV using radioactive sources and employing $^{11}B(p,\\gamma)$ reaction at $E_p$ = 163 keV and $E_p$ = 7.2 MeV. The linearity of energy response of the LaBr$_3$(Ce) detector is tested upto 22.6 MeV using three different voltage dividers. The data acquisition system using CAEN digitizers is set up and optimized to get the best energy and time resolution. The energy resolution of $\\sim$ 2.1% at $E_\\gamma$ = 22.6~MeV is measured for configuration giving best linearity upto high energy. Time resolution of the phoswich detector is measured with $^{60}$Co source after implementing CFD algorithm for the digitized pulses and is found to be excellent (FWHM $\\sim$ 315~ps). In order to study the effect...

  9. First Light: MeV Astrophysics from the Moon

    Science.gov (United States)

    Miller, Richard S.; Lawrence, David J.

    2016-06-01

    We report evidence of the first astrophysical source detected from the Moon at MeV energies. Our detection of Cygnus X-1 is a validation of a new investigative paradigm in which the lunar environment is intrinsic to the detection approach: the Lunar Occultation Technique (LOT). NASA’s Lunar Prospector mission served as a proxy for a dedicated LOT-based mission. The characteristic signature of temporal modulation, generated by repeated lunar occultations and encoded within acquired gamma-ray data (0.5-9 MeV), is consistent with an unambiguous detection of Cygnus X-1 at 5.4σ significance. Source localization and long-term monitoring capabilities of the LOT are also demonstrated. This “first light” detection verifies the basic tenets of the LOT methodology, reinforces its feasibility as an alternative astronomical detection paradigm for nuclear astrophysics investigations, and is an illustration of the fundamental benefits of the Moon as a platform for science.

  10. Shielding data for 100-250 MeV proton accelerators double differential neutron distributions and attenuation in concrete

    CERN Document Server

    Agosteo, S; Mereghetti, A; Silari, M; Zajacova, Z

    2007-01-01

    Double differential distributions of neutrons produced by 100, 150, 200 and 250 MeV protons stopped in a thick iron target were simulated with the FLUKA Monte Carlo code at four emission angles: forward, 45°, transverse and 135° backwards. The attenuation in ordinary concrete of the dose equivalent due to secondary neutrons, protons, photons and electrons was calculated. Some of the resulting attenuation curves are best fitted by a double-exponential function rather than a single-exponential. The effect of various approximations introduced in the simulations is thoroughly discussed. The contribution to the total ambient dose equivalent from photons and protons is usually limited to a few percent, except in the backward direction where photons contribute more than 10% and up to 35% to the total dose for a shield thickness of 1 – 2 m. Source terms and attenuation lengths are given as a function of energy and emission angle, along with fit to the Monte Carlo data. An extensive comparison is made of values ob...

  11. Evolution of the 400 MeV linac design

    Energy Technology Data Exchange (ETDEWEB)

    MacLachlan, J.A.

    1987-11-09

    The basic premises of the conceptual design for the linac upgrade are pursued to establish lengths, gradients, power dissipation, etc., for the 400 MeV linac and matching section. The discussion is limited to accelerating and focusing components. Wherever values depend on the choice of the accelerating structure, the disk-and-washer structure is emphasized; the results are generally relevant to the side coupled cavity choice also.

  12. Construction of a pulsed MeV positron beam line

    Energy Technology Data Exchange (ETDEWEB)

    Masuno, Shin-ichi; Okada, Sohei; Kawasuso, Atsuo [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    1997-03-01

    To develop a fast (1 MeV) and short pulsed (100 ps) positron beam which enables defect behavior analysis of bulk states of materials even at high temperatures where a usual positron source would melt, we have been performing design study and construction of the beam line in a three-year program since 1994. This report describes the components, design study results and experimental results of the completed parts until now. (author)

  13. RADIATION DAMAGE TO BSCCO-2223 FROM 50 MEV PROTONS

    Energy Technology Data Exchange (ETDEWEB)

    Zeller, A.F.; Ronningen, R.M.; Godeke, Arno; Heibronn, L.H; McMahan-Norris, P.; Gupta, R.

    2007-11-01

    The use of HTS materials in high radiation environments requires that the superconducting properties remain constant up to a radiation high dose. BSCCO-2223 samples from two manufacturers were irradiated with 50 MeV protons at fluences of up to 5 x 10{sup 17} protons/cm{sup 2}. The samples lost approximately 75% of their pre-irradiation I{sub c}. This compares with Nb{sub 3}Sn, which loses about 50% at the same displacements per atom.

  14. RADIATION DAMAGE TO BSCCO-2223 FROM 50 MEV PROTONS

    Energy Technology Data Exchange (ETDEWEB)

    Zeller, A.F.; Ronningen, R.M.; Godeke, A.; Heilbronn, L.H.; McMahan-Norris, P.; Gupta, R.

    2007-11-27

    The use of HTS materials in high radiation environmentsrequires that the superconducting properties remain constant up to aradiation high dose. BSCCO-2223 samples from two manufacturers wereirradiated with 50 MeV protons at fluences of up to 5 x 1017 protons/cm2.The samples lost approximately 75 percent of their pre-irradiation Ic.This compares with Nb3Sn, which loses about 50 percent at the samedisplacements per atom.

  15. Hybrid photon detectors

    CERN Document Server

    D'Ambrosio, C

    2003-01-01

    Hybrid photon detectors detect light via vacuum photocathodes and accelerate the emitted photoelectrons by an electric field towards inversely polarized silicon anodes, where they are absorbed, thus producing electron-hole pairs. These, in turn, are collected and generate electronic signals on their ohmic contacts. This review first describes the characteristic properties of the main components of hybrid photon detectors: light entrance windows, photocathodes, and silicon anodes. Then, essential relations describing the trajectories of photoelectrons in electric and magnetic fields and their backscattering from the silicon anodes are derived. Depending on their anode configurations, three families of hybrid photon detectors are presented: hybrid photomultiplier tubes with single anodes for photon counting with high sensitivity and for gamma spectroscopy; multi-anode photon detector tubes with anodes subdivided into square or hexagonal pads for position-sensitive photon detection; imaging silicon pixel array t...

  16. Single-photon imaging

    CERN Document Server

    Seitz, Peter

    2011-01-01

    The acquisition and interpretation of images is a central capability in almost all scientific and technological domains. In particular, the acquisition of electromagnetic radiation, in the form of visible light, UV, infrared, X-ray, etc. is of enormous practical importance. The ultimate sensitivity in electronic imaging is the detection of individual photons. With this book, the first comprehensive review of all aspects of single-photon electronic imaging has been created. Topics include theoretical basics, semiconductor fabrication, single-photon detection principles, imager design and applications of different spectral domains. Today, the solid-state fabrication capabilities for several types of image sensors has advanced to a point, where uncoooled single-photon electronic imaging will soon become a consumer product. This book is giving a specialist´s view from different domains to the forthcoming “single-photon imaging” revolution. The various aspects of single-photon imaging are treated by internati...

  17. Two-photon physics

    Energy Technology Data Exchange (ETDEWEB)

    Bardeen, W.A.

    1981-10-01

    A new experimental frontier has recently been opened to the study of two photon processes. The first results of many aspects of these reactions are being presented at this conference. In contrast, the theoretical development of research ito two photon processes has a much longer history. This talk reviews the many different theoretical ideas which provide a detailed framework for our understanding of two photon processes.

  18. Advanced Photon Source (APS)

    Data.gov (United States)

    Federal Laboratory Consortium — The Advanced Photon Source (APS) at the U.S. Department of Energy's Argonne National Laboratoryprovides this nation's (in fact, this hemisphere's) brightest storage...

  19. Effects of Longitudinal Photons

    CERN Document Server

    Friberg, C; Friberg, Christer; Sjöstrand, Torbjörn

    2000-01-01

    The description of longitudinal photons is far from trivial, and their phenomenological importance is largely unknown. While the cross section for direct interactions is calculable, an even more important contribution could come from resolved states. In the development of our model for the interactions of (real and) virtual photons, we have modeled resolved longitudinal effects by simple multiplicative factors on the resolved transverse-photon contributions. Recently, a first set of parton distributions for longitudinal virtual photons has been presented by Ch\\'yla. We therefore compare their impact on some representative distributions, relative to the simpler approaches.

  20. Photonic Integrated Circuits

    Science.gov (United States)

    Krainak, Michael; Merritt, Scott

    2016-01-01

    Integrated photonics generally is the integration of multiple lithographically defined photonic and electronic components and devices (e.g. lasers, detectors, waveguides passive structures, modulators, electronic control and optical interconnects) on a single platform with nanometer-scale feature sizes. The development of photonic integrated circuits permits size, weight, power and cost reductions for spacecraft microprocessors, optical communication, processor buses, advanced data processing, and integrated optic science instrument optical systems, subsystems and components. This is particularly critical for small spacecraft platforms. We will give an overview of some NASA applications for integrated photonics.

  1. Integrated microwave photonics

    CERN Document Server

    Marpaung, David; Heideman, Rene; Leinse, Arne; Sales, Salvador; Capmany, Jose

    2012-01-01

    Microwave photonics (MWP) is an emerging field in which radio frequency (RF) signals are generated, distributed, processed and analyzed using the strength of photonic techniques. It is a technology that enables various functionalities which are not feasible to achieve only in the microwave domain. A particular aspect that recently gains significant interests is the use of photonic integrated circuit (PIC) technology in the MWP field for enhanced functionalities and robustness as well as the reduction of size, weight, cost and power consumption. This article reviews the recent advances in this emerging field which is dubbed as integrated microwave photonics. Key integrated MWP technologies are reviewed and the prospective of the field is discussed.

  2. Biomedical photonics handbook

    CERN Document Server

    Vo-Dinh, Tuan

    2003-01-01

    1.Biomedical Photonics: A Revolution at the Interface of Science and Technology, T. Vo-DinhPHOTONICS AND TISSUE OPTICS2.Optical Properties of Tissues, J. Mobley and T. Vo-Dinh3.Light-Tissue Interactions, V.V. Tuchin 4.Theoretical Models and Algorithms in Optical Diffusion Tomography, S.J. Norton and T. Vo-DinhPHOTONIC DEVICES5.Laser Light in Biomedicine and the Life Sciences: From the Present to the Future, V.S. Letokhov6.Basic Instrumentation in Photonics, T. Vo-Dinh7.Optical Fibers and Waveguides for Medical Applications, I. Gannot and

  3. Review on Dark Photon

    Directory of Open Access Journals (Sweden)

    Curciarello Francesca

    2016-01-01

    Full Text Available e+e− collider experiments at the intensity frontier are naturally suited to probe the existence of a force beyond the Standard Model between WIMPs, the most viable dark matter candidates. The mediator of this new force, known as dark photon, should be a new vector gauge boson very weakly coupled to the Standard Model photon. No significant signal has been observed so far. I will report on current limits set on the coupling factor ε2 between the photon and the dark photon by e+e− collider experiments.

  4. Study of the characteristics of neutron monitor area applied to the evaluation of dose rates in a 15 MeV radiotherapy accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Candido M. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Fisica]. E-mail: candido_1998@yahoo.com; Patrao, Karla C.S.; Pereira, Walsan W.; Fonseca, Evaldo S.; Giannoni, Ricardo A. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Lab. de Neutrons]. E-mails: karla@ird.gov.br; walsan@ird.gov.br; Batista, Delano V.S. [Instituto Nacional do Cancer (INCa), Rio de Janeiro, RJ (Brazil). Setor de Fisica Medica]. E-mail: delano@inca.gov.br

    2007-07-01

    Currently, in Radiotherapy, the use of linear accelerators is becoming each time more common. From Radiation Protection point of view, these instruments represent an advance in relation to the cobalt and caesium irradiators, mainly due to absence of the radioactive material. On the other hand, accelerators with the energies superior to 10 MeV produce contamination of the therapeutic beam with the presence of neutrons generated in the interaction of high-energy photons with high atomic number materials from the own irradiator. The present work carries through measurements in a linear accelerator of 15 MeV using three neutron area monitors for a comparison of the response of these instruments, evaluating its adequacy to this measurement. Characteristics of use and operation associates to parameters such as: monitor dead time, monitor gamma rejection, and calibration results are also analyzed in this study. (author)

  5. Application of calorimeters for 5 MeV EB and bremsstrahlung dosimetry

    DEFF Research Database (Denmark)

    Sato, T.; Takahashi, T.; Saito, T.;

    1993-01-01

    Graphite and water calorimeters, which were developed for use a 10 MeV electron beams (EB) at Riso National Laboratory, were used for process validation and routine dosimeter calibration at a 5 MeV EB. Water calorimeters were used for reference measurements for 5 MeV EB, the response was found...... at 5 MeV EB. Graphite calorimeters gave reproducible readings within 3.3 % relative errors (95 % confidence level) for X-ray measurement....

  6. A dynamic programming approach for quickly estimating large network-based MEV models

    DEFF Research Database (Denmark)

    Mai, Tien; Frejinger, Emma; Fosgerau, Mogens

    2017-01-01

    by a rooted, directed graph where each node without successor is an alternative. We formulate a family of MEV models as dynamic discrete choice models on graphs of correlation structures and show that the dynamic models are consistent with MEV theory and generalize the network MEV model (Daly and Bierlaire...

  7. First H- beam accelerated at Linac4: 3MeV done, 157 MeV to go!

    CERN Multimedia

    Linac4 Project Team

    2013-01-01

    On 14 November, the first H- (one proton surrounded by two electrons) beam was accelerated to the energy of 3 MeV in the Linac4 - the new linear accelerator that will replace Linac2 as low-energy injector in the LHC accelerator chain.      A view of the Linac4 taken during the recent tests (top image) and the current measured by the instruments at the end of the acceleration line on 14 November (bottom image). Images: Linac4 collaboration. Using the recently installed Radio Frequency Quadrupole (RFQ) accelerator, 13 mA of current were accelerated to the energy of 3 MeV. After the successful commissioning of the Linac4 RFQ at the 3 MeV test stand completed during the first months of 2013, the whole equipment (composed of the RFQ itself, the following Medium Energy Beam Transport line and its diagnostic line) were moved to the Linac4 tunnel during summer and installed in their final position. In the meantime, a new ion source was assembled, installed and successfu...

  8. First measurement of the polarisation asymmetry of a gamma-ray beam between 1.7 to 74 MeV with the HARPO TPC

    Science.gov (United States)

    Gros, P.; Amano, S.; Attié, D.; Bernard, D.; Bruel, P.; Calvet, D.; Colas, P.; Daté, S.; Delbart, A.; Frotin, M.; Geerebaert, Y.; Giebels, B.; Götz, D.; Hashimoto, S.; Horan, D.; Kotaka, T.; Louzir, Marc; Minamiyama, Y.; Miyamoto, S.; Ohkuma, H.; Poilleux, Patrick; Semeniouk, I.; Sizun, P.; Takemoto, A.; Yamaguchi, M.; Wang, S.

    2016-07-01

    Current γ-ray telescopes suffer from a gap in sensitivity in the energy range between 100 keV and 100 MeV, and no polarisation measurement has ever been done on cosmic sources above 1 MeV. Past and present e+e- pair telescopes are limited at lower energies by the multiple scattering of electrons in passive tungsten converter plates. This results in low angular resolution, and, consequently, a drop in sensitivity to point sources below 1 GeV. The polarisation information, which is carried by the azimuthal angle of the conversion plane, is lost for the same reasons. HARPO is an R&D program to characterise the operation of a gaseous detector (a Time Projection Chamber or TPC) as a high angular-resolution and sensitivity telescope and polarimeter for γ-rays from cosmic sources. It represents a first step towards a future space instrument in the MeV-GeV range. We built and characterised a 30cm cubic demonstrator [SPIE 91441M], and put it in a polarised γ-ray beam at the NewSUBARU accelerator in Japan. Data were taken at photon energies from 1.74MeV to 74MeV and with different polarisation configurations. We describe the experimental setup in beam. We then describe the software we developed to reconstruct the photon conversion events, with special focus on low energies. We also describe the thorough simulation of the detector used to compare results. Finally we will present the performance of the detector as extracted from this analysis and preliminary measurements of the polarisation asymmetry. This beam-test qualification of a gas TPC prototype in a γ-ray beam could open the way to high-performance -ray astronomy and polarimetry in the MeV-GeV energy range in the near future.

  9. Shielding variation effects for 250 MeV protons on tissue targets.

    Science.gov (United States)

    Brandl, A; Hranitzky, C; Rollet, S

    2005-01-01

    This paper provides results of computer simulation studies with the goal to analyse issues regarding radiation protection for personnel, patients and third persons involved in hadron therapy treatment. The treatment room and the patient are modelled by simple cylindrical geometries at incident proton energies of 250 MeV. Monte Carlo simulations of the energy and angular dependence of proton, neutron and photon radiation fields and resulting ambient dose equivalent distributions outside the shielding walls are performed. In order to investigate systematic uncertainties due to the shielding materials and inherent to the computer models, various concrete compositions, densities and water contents are modelled, and the influence of simulation parameters on the results obtained is determined. Generally, good agreement is found between results provided by MCNPX and FLUKA computer codes. Variations in neutron ambient dose attenuation from -50 to +/-30% are found due to varying concrete composition. Changes in the water content of the concrete in the order of 8% may cause variations up to 20%.

  10. Photonic Crystal Fiber Attenuator

    Institute of Scientific and Technical Information of China (English)

    Joo; Beom; Eom; Hokyung; Kim; Jinchae; Kim; Un-Chul; Paek; Byeong; Ha; Lee

    2003-01-01

    We propose a novel fiber attenuator based on photonic crystal fibers. The difference in the modal field diameters of a conventional single mode fiber and a photonic crystal fiber was used. A variable optical attenuator was also achieved by applying macro-bending on the PCF part of the proposed attenuator

  11. Photon mass from inflation.

    Science.gov (United States)

    Prokopec, Tomislav; Törnkvist, Ola; Woodard, Richard

    2002-09-01

    We consider vacuum polarization from massless scalar electrodynamics in de Sitter inflation. The theory exhibits a 3+1 dimensional analog of the Schwinger mechanism in which a photon mass is dynamically generated. The mechanism is generic for light scalar fields that couple minimally to gravity. The nonvanishing of the photon mass during inflation may result in magnetic fields on cosmological scales.

  12. Superconducting Single Photon Detectors

    NARCIS (Netherlands)

    Dorenbos, S.N.

    2011-01-01

    This thesis is about the development of a detector for single photons, particles of light. New techniques are being developed that require high performance single photon detection, such as quantum cryptography, single molecule detection, optical radar, ballistic imaging, circuit testing and fluoresc

  13. ALICE Photon Multiplicity Detector

    CERN Multimedia

    Nayak, T

    2013-01-01

    Photon Multiplicity Detector (PMD) measures the multiplicity and spatial distribution of photons in the forward region of ALICE on a event-by-event basis. PMD is a pre-shower detector having fine granularity and full azimuthal coverage in the pseudo-rapidity region 2.3 < η < 3.9.

  14. Diffusion Based Photon Mapping

    DEFF Research Database (Denmark)

    Schjøth, Lars; Sporring, Jon; Fogh Olsen, Ole

    2008-01-01

    . To address this problem, we introduce a photon mapping algorithm based on nonlinear anisotropic diffusion. Our algorithm adapts according to the structure of the photon map such that smoothing occurs along edges and structures and not across. In this way, we preserve important illumination features, while...

  15. Absolute Calibration of Image Plate for electrons at energy between 100 keV and 4 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Chen, H; Back, N L; Eder, D C; Ping, Y; Song, P M; Throop, A

    2007-12-10

    The authors measured the absolute response of image plate (Fuji BAS SR2040) for electrons at energies between 100 keV to 4 MeV using an electron spectrometer. The electron source was produced from a short pulse laser irradiated on the solid density targets. This paper presents the calibration results of image plate Photon Stimulated Luminescence PSL per electrons at this energy range. The Monte Carlo radiation transport code MCNPX results are also presented for three representative incident angles onto the image plates and corresponding electron energies depositions at these angles. These provide a complete set of tools that allows extraction of the absolute calibration to other spectrometer setting at this electron energy range.

  16. Effective atomic numbers, electron densities and kinetic energy released in matter of vitamins for photon interaction

    Science.gov (United States)

    Shantappa, A.; Hanagodimath, S. M.

    2014-01-01

    Effective atomic numbers, electron densities of some vitamins (Retinol, Riboflavin, Niacin, Biotin, Folic acid, Cobalamin, Phylloquinone and Flavonoids) composed of C, H, O, N, Co, P and S have been calculated for total and partial photon interactions by the direct method for energy range 1 keV-100 GeV by using WinXCOM and kinetic energy released in matter (Kerma) relative to air is calculated in energy range of 1 keV-20 MeV. Change in effective atomic number and electron density with energy is calculated for all photon interactions. Variation of photon mass attenuation coefficients with energy are shown graphically only for total photon interaction. It is observed that change in mass attenuation coefficient with composition of different chemicals is very large below 100 keV and moderate between 100 keV and 10 MeV and negligible above 10 MeV. Behaviour of vitamins is almost indistinguishable except biotin and cobalamin because of large range of atomic numbers from 1(H) to 16 (S) and 1(H) to 27(Co) respectively. K a value shows a peak due to the photoelectric effect around K-absorption edge of high- Z constituent of compound for biotin and cobalamin.

  17. A consistent set of neutron kerma coefficients from thermal to 150 MeV for biologically important materials

    Energy Technology Data Exchange (ETDEWEB)

    Chadwick, M.B. [University of California, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Barschall, H.H. [Department of Medical Physics, University of Wisconsin, Madison, Wisconsin 53706-1532 (United States); Caswell, R.S. [National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); DeLuca, P.M. [Department of Medical Physics, University of Wisconsin, Madison, Wisconsin 53706-1532 (United States); Hale, G.M. [University of California, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Jones, D.T. [National Accelerator Centre, Faure, CapeTown (South Africa); MacFarlane, R.E. [University of California, Los Alamos, National Laboratory, Los Alamos, New Mexico 87545 (United States); Meulders, J.P. [Universite Catholique de Louvain, Louvain-la-Neuve (Belgium); Schuhmacher, H.; Schrewe, U.J. [Physikalisch-Technische Bundesanstalt, Braunschweig (Germany); Wambersie, A. [Universite Catholique de Louvain, Louvain-la-Neuve (Belgium); Young, P.G. [University of California, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    1999-06-01

    Neutron cross sections for nonelastic and elastic reactions on a range of elements have been evaluated for incident energies up to 150 MeV. These cross sections agree well with experimental cross section data for charged-particle production as well as neutron and photon production. Therefore they can be used to determine kerma coefficients for calculations of energy deposition by neutrons in matter. Methods used to evaluate the neutron cross sections above 20 MeV, using nuclear model calculations and experimental data, are described. Below 20 MeV, the evaluated cross sections from the ENDF/B-VI library are adopted. Comparisons are shown between the evaluated charged-particle production cross sections and measured data. Kerma coefficients are derived from the neutron cross sections, for major isotopes of H, C, N, O, Al, Si, P, Ca, Fe, Cu, W, Pb, and for ICRU-muscle, A-150 tissue-equivalent plastic, and other compounds important for treatment planning and dosimetry. Numerous comparisons are made between our kerma coefficients and experimental kerma coefficient data, to validate our results, and agreement is found to be good. An important quantity in neutron dosimetry is the kerma coefficient ratio of ICRU-muscle to A-150 plastic. When this ratio is calculated from our kerma coefficient data, and averaged over the neutron energy spectra for higher-energy clinical therapy beams [three p(68)+Be beams, and a d(48.5)+Be beam], a value of 0.94{plus_minus}0.03 is obtained. Kerma ratios for water to A-150 plastic, and carbon to oxygen, are also compared with measurements where available. {copyright} {ital 1999 American Association of Physicists in Medicine.}

  18. Research and development of a gamma-ray imaging spectrometer in the MeV range in Barcelona

    Science.gov (United States)

    Alvarez, José-Manuel; Galvez, José-Luis; Hernanz, Margarita; Isern, Jordi; Lozano, Manuel; Pellegrini, Giulio; Chmeissani, Mokhtar; Cabruja, Enric; Ullán, Miguel

    2010-07-01

    Gamma-ray astrophysics in the MeV energy range plays an important role for the understanding of cosmic explosions and acceleration mechanisms in a variety of galactic and extragalactic sources, e.g., Supernovae, Classical Novae, Supernova Remnants (SNRs), Gamma-Ray Bursts (GRBs), Pulsars, Active Galactic Nuclei (AGN). Through the development of focusing telescopes in the MeV energy range, it will be possible to reach unprecedented sensitivities, compared with those of the currently operating gamma ray telescopes. In order to achieve the needed performance, a detector with mm spatial resolution and very high peak efficiency is required. It will be also desirable that the detector could detect polarization of the source. Our research and development activities in Barcelona aim to study a gamma-ray imaging spectrometer in the MeV range suited for the focal plane of a gamma-ray telescope mission, based on CdTe pixel detectors arranged in multiple layers with increasing thicknesses, to enhance gamma-ray absorption in the Compton regime. We have developed an initial prototype based on several CdTe module detectors, with 11x11 pixels, a pixel pitch of 1mm and a thickness of 2mm. Each pixel is stud-bump bonded to a fanout board and routed to a readout ASIC to measure pixel position, pulse height and rise time information for each incident gamma-ray photon. We will report on the results of an optimization study based on simulations, to select the optimal thickness of each CdTe detector within the module to get the best energy resolution of the spectrometer.

  19. Function Photonic Crystals

    CERN Document Server

    Wu, Xiang-Yao; Yang, Jing-Hai; Liu, Xiao-Jing; Ba, Nuo; Wu, Yi-Heng; Wang, Qing-Cai; Li, Jing-Wu

    2010-01-01

    In the paper, we present a new kind of function photonic crystals, which refractive index is a function of space position. Unlike conventional PCs, which structure grow from two materials, A and B, with different dielectric constants $\\epsilon_{A}$ and $\\epsilon_{B}$. By Fermat principle, we give the motion equations of light in one-dimensional, two-dimensional and three-dimensional function photonic crystals. For one-dimensional function photonic crystals, we study the dispersion relation, band gap structure and transmissivity, and compare them with conventional photonic crystals. By choosing various refractive index distribution function $n(z)$, we can obtain more width or more narrow band gap structure than conventional photonic crystals.

  20. A novel photonic oscillator

    Science.gov (United States)

    Yao, X. S.; Maleki, L.

    1995-01-01

    We report a novel oscillator for photonic RF systems. This oscillator is capable of generating high-frequency signals up to 70 GHz in both electrical and optical domains and is a special voltage-controlled oscillator with an optical output port. It can be used to make a phase-locked loop (PLL) and perform all functions that a PLL is capable of for photonic systems. It can be synchronized to a reference source by means of optical injection locking, electrical injection locking, and PLL. It can also be self-phase locked and self-injection locked to generate a high-stability photonic RF reference. Its applications include high-frequency reference regeneration and distribution, high-gain frequency multiplication, comb-frequecy and square-wave generation, carrier recovery, and clock recovery. We anticipate that such photonic voltage-controlled oscillators (VCOs) will be as important to photonic RF systems as electrical VCOs are to electrical RF systems.

  1. Chirality in photonic systems

    Science.gov (United States)

    Solnyshkov, Dmitry; Malpuech, Guillaume

    2016-10-01

    The optical modes of photonic structures are the so-called TE and TM modes that bring intrinsic spin-orbit coupling and chirality to these systems. This, combined with the unique flexibility of design of the photonic potential, and the possibility to mix photon states with excitonic resonances, sensitive to magnetic field and interactions, allows us to achieve many phenomena, often analogous to other solid-state systems. In this contribution, we review in a qualitative and comprehensive way several of these realizations, namely the optical spin Hall effect, the creation of spin currents protected by a non-trivial geometry, the Berry curvature for photons, and the photonic/polaritonic topological insulator.

  2. Photon regeneration plans

    Energy Technology Data Exchange (ETDEWEB)

    Ringwald, A.

    2006-12-15

    Precision experiments exploiting low-energy photons may yield information on particle physics complementary to experiments at high-energy colliders, in particular on new very light and very weakly interacting particles, predicted in many extensions of the standard model. Such particles may be produced by laser photons send along a transverse magnetic field. The laser polarization experiment PVLAS may have seen the first indirect signal of such particles by observing an anomalously large rotation of the polarization plane of photons after the passage through a magnetic field. This can be interpreted as evidence for photon disappearance due to particle production. There are a number of experimental proposals to test independently the particle interpretation of PVLAS. Many of them are based on the search for photon reappearance or regeneration, i.e. for ''light shining through a wall''. At DESY, the Axion-Like Particle Search (ALPS) collaboration is currently setting up such an experiment. (orig.)

  3. Photon Regeneration Plans

    CERN Document Server

    Ringwald, A

    2006-01-01

    Precision experiments exploiting low-energy photons may yield information on particle physics complementary to experiments at high-energy colliders, in particular on new very light and very weakly interacting particles, predicted in many extensions of the standard model. Such particles may be produced by laser photons send along a transverse magnetic field. The laser polarization experiment PVLAS may have seen the first indirect signal of such particles by observing an anomalously large rotation of the polarization plane of photons after the passage through a magnetic field. This can be interpreted as evidence for photon disappearance due to particle production. There are a number of experimental proposals to test independently the particle interpretation of PVLAS. Many of them are based on the search for photon reappearance or regeneration, i.e. for ``light shining through a wall''. At DESY, the Axion-Like Particle Search (ALPS) collaboration is currently setting up such an experiment.

  4. Nonlinear Photonics 2014: introduction.

    Science.gov (United States)

    Akhmediev, N; Kartashov, Yaroslav

    2015-01-12

    International Conference "Nonlinear Photonics-2014" took place in Barcelona, Spain on July 27-31, 2014. It was a part of the "Advanced Photonics Congress" which is becoming a traditional notable event in the world of photonics. The current focus issue of Optics Express contains contributions from the participants of the Conference and the Congress. The articles in this focus issue by no means represent the total number of the congress contributions (around 400). However, it demonstrates wide range of topics covered at the event. The next conference of this series is to be held in 2016 in Australia, which is the home of many researchers working in the field of photonics in general and nonlinear photonics in particular.

  5. Photonic Crystal Fibres

    DEFF Research Database (Denmark)

    Bjarklev, Anders Overgaard; Broeng, Jes; Sanchez Bjarklev, Araceli

    Photonic crystal fibres represent one of the most active research areas today in the field of optics. The diversity of applications that may be addressed by these fibres and their fundamental appeal, by opening up the possibility of guiding light in a radically new way compared to conventional...... optical fibres, have spun an interest from almost all areas of optics and photonics. The aim of this book is to provide an understanding of the different types of photonic crystal fibres and to outline some of the many new and exciting applications that these fibres offer. The book is intended for both...... readers with a general interest in photonic crystals, as well as for scientists who are entering the field and desire a broad overview as well as a solid starting point for further specialized stuides. Teh book, therefore, covers bothe general aspects such as the link from classical optics to photonic...

  6. A study of Rhizophora spp wood phantom for dosimetric purposes using high-energy photon and electron beams

    Energy Technology Data Exchange (ETDEWEB)

    Banjade, D.P. E-mail: dpbl4007@stud.usm.my; Tajuddin, A.A.; Shukri, A

    2001-09-01

    Previous scattering and depth-dose investigations involving use of the Malaysian hardwood Rhizophora spp have shown this medium to produce good agreement with measurements made in water. Present study extends the comparison, now including measurements of percentage depth-dose made for photons at 6 MV and 5 and 12 MeV electron beams. For the 6 MV photon and 5 MeV electron beams, discrepancies between percentage depth-dose for Rhizophora spp and water, at all depths, are found to be within 2.6 and 2.4% respectively. At 12 MeV electron energies, measured percentage depth-doses in Rhizophora spp beyond 3.5 cm depth are found to be in significant discord with those for water. The absorbed dose in water measured in Rhizophora spp at d{sub max} for all three beams produces discrepancies of no more than 1.1% when compared with measurements made in water.

  7. Roadmap on silicon photonics

    Science.gov (United States)

    Thomson, David; Zilkie, Aaron; Bowers, John E.; Komljenovic, Tin; Reed, Graham T.; Vivien, Laurent; Marris-Morini, Delphine; Cassan, Eric; Virot, Léopold; Fédéli, Jean-Marc; Hartmann, Jean-Michel; Schmid, Jens H.; Xu, Dan-Xia; Boeuf, Frédéric; O'Brien, Peter; Mashanovich, Goran Z.; Nedeljkovic, M.

    2016-07-01

    Silicon photonics research can be dated back to the 1980s. However, the previous decade has witnessed an explosive growth in the field. Silicon photonics is a disruptive technology that is poised to revolutionize a number of application areas, for example, data centers, high-performance computing and sensing. The key driving force behind silicon photonics is the ability to use CMOS-like fabrication resulting in high-volume production at low cost. This is a key enabling factor for bringing photonics to a range of technology areas where the costs of implementation using traditional photonic elements such as those used for the telecommunications industry would be prohibitive. Silicon does however have a number of shortcomings as a photonic material. In its basic form it is not an ideal material in which to produce light sources, optical modulators or photodetectors for example. A wealth of research effort from both academia and industry in recent years has fueled the demonstration of multiple solutions to these and other problems, and as time progresses new approaches are increasingly being conceived. It is clear that silicon photonics has a bright future. However, with a growing number of approaches available, what will the silicon photonic integrated circuit of the future look like? This roadmap on silicon photonics delves into the different technology and application areas of the field giving an insight into the state-of-the-art as well as current and future challenges faced by researchers worldwide. Contributions authored by experts from both industry and academia provide an overview and outlook for the silicon waveguide platform, optical sources, optical modulators, photodetectors, integration approaches, packaging, applications of silicon photonics and approaches required to satisfy applications at mid-infrared wavelengths. Advances in science and technology required to meet challenges faced by the field in each of these areas are also addressed together with

  8. Photo-fission Product Yield Measurements at Eγ=13 MeV on 235U, 238U, and 239Pu

    Science.gov (United States)

    Tornow, W.; Bhike, M.; Finch, S. W.; Krishichayan, Fnu; Tonchev, A. P.

    2016-09-01

    We have measured Fission Product Yields (FPYs) in photo-fission of 235U, 238U, and 239Pu at TUNL's High-Intensity Gamma-ray Source (HI γS) using mono-energetic photons of Eγ = 13 MeV. Details of the experimental setup and analysis procedures will be discussed. Yields for approximately 20 fission products were determined. They are compared to neutron-induced FPYs of the same actinides at the equivalent excitation energies of the compound nuclear systems. In the future photo-fission data will be taken at Eγ = 8 . 0 and 10.5 MeV to find out whether photo-fission exhibits the same so far unexplained dependence of certain FPYs on the energy of the incident probe, as recently observed in neutron-induced fission, for example, for the important fission product 147Nd. Work supported by the U. S. Dept. of Energy, under Grant No. DE-FG02-97ER41033, and by the NNSA, Stewardship Science Academic Alliances Program, Grant No. DE-NA0001838 and the Lawrence Livermore, National Security, LLC under Contract No. DE-AC52-07NA27344.

  9. Monte Carlo simulations and benchmark measurements on the response of TE(TE) and Mg(Ar) ionization chambers in photon, electron and neutron beams

    Science.gov (United States)

    Lin, Yi-Chun; Huang, Tseng-Te; Liu, Yuan-Hao; Chen, Wei-Lin; Chen, Yen-Fu; Wu, Shu-Wei; Nievaart, Sander; Jiang, Shiang-Huei

    2015-06-01

    The paired ionization chambers (ICs) technique is commonly employed to determine neutron and photon doses in radiology or radiotherapy neutron beams, where neutron dose shows very strong dependence on the accuracy of accompanying high energy photon dose. During the dose derivation, it is an important issue to evaluate the photon and electron response functions of two commercially available ionization chambers, denoted as TE(TE) and Mg(Ar), used in our reactor based epithermal neutron beam. Nowadays, most perturbation corrections for accurate dose determination and many treatment planning systems are based on the Monte Carlo technique. We used general purposed Monte Carlo codes, MCNP5, EGSnrc, FLUKA or GEANT4 for benchmark verifications among them and carefully measured values for a precise estimation of chamber current from absorbed dose rate of cavity gas. Also, energy dependent response functions of two chambers were calculated in a parallel beam with mono-energies from 20 keV to 20 MeV photons and electrons by using the optimal simple spherical and detailed IC models. The measurements were performed in the well-defined (a) four primary M-80, M-100, M120 and M150 X-ray calibration fields, (b) primary 60Co calibration beam, (c) 6 MV and 10 MV photon, (d) 6 MeV and 18 MeV electron LINACs in hospital and (e) BNCT clinical trials neutron beam. For the TE(TE) chamber, all codes were almost identical over the whole photon energy range. In the Mg(Ar) chamber, MCNP5 showed lower response than other codes for photon energy region below 0.1 MeV and presented similar response above 0.2 MeV (agreed within 5% in the simple spherical model). With the increase of electron energy, the response difference between MCNP5 and other codes became larger in both chambers. Compared with the measured currents, MCNP5 had the difference from the measurement data within 5% for the 60Co, 6 MV, 10 MV, 6 MeV and 18 MeV LINACs beams. But for the Mg(Ar) chamber, the derivations reached 7

  10. Searching hidden-sector photons inside a superconducting box

    Energy Technology Data Exchange (ETDEWEB)

    Jaeckel, J. [Durham Univ. (United Kingdom). Inst. for Particle Physics Phenomenology; Redondo, J. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2008-06-15

    We propose an experiment to search for extra ''hidden-sector'' U(1) gauge bosons with gauge kinetic mixing with the ordinary photon, predicted by many extensions of the Standard Model. The setup consists of a highly sensitive magnetometer inside a superconducting shielding. This is then placed inside a strong (but sub-critical) magnetic field. In ordinary electrodynamics the magnetic field cannot permeate the superconductor and no field should register on the magnetometer. However, photon - hidden-sector photon - photon oscillations would allow to penetrate the superconductor and the magnetic field would ''leak'' into the shielded volume and register on the magnetometer. Although this setup resembles a classic ''light shining though a wall experiment'' there are two crucial differences. First, the fields are (nearly) static and the photons involved are virtual. Second, the magnetometer directly measures the field-strength and not a probability. This improves the dependence of the signal on the kinetic mixing {chi}<<1 to {chi}{sup 2} instead of {chi}{sup 4}. In the mass range 2 {mu}eVmeV the projected sensitivity is in the {chi} {proportional_to} 5 x 10{sup -9} to {chi} {proportional_to} 10{sup -6} range. This surpasses current astrophysical and laboratory limits by several orders of magnitude - ample room to discover new physics. (orig.)

  11. Annealing behaviour of MeV erbium implanted lithium niobate

    Energy Technology Data Exchange (ETDEWEB)

    Gortmaker, P.; McCallum, J.C. [Royal Melbourne Inst. of Tech., VIC (Australia)

    1993-12-31

    Lithium niobate (LiNbO{sub 3}) is a crystalline ceramic commonly used in the fabrication of optoelectronic devices. Recently, rare earth doping of LiNbO{sub 3} has become a topic of particular interest. The electronic configuration of rare earth elements such as Erbium (Er) and Neodymium (Nd) allows them to lase in nearly any host matrix making fabrication of a whole range of new optoelectronic devices possible. At present, the doping technique, for LiNbO{sub 3} are centred upon diffusion technology, but the diffusion profiles for the rare earths are not generally well-matched to the optical modes of the device. The aim of this research is to develop MeV implantation and annealing conditions of rare earth doped LiNbO{sub 3} that would be compatible with optoelectronic device fabrication. To determine the characteristics of the rare earth elements in the LiNbO{sub 3} host material over the depth range of interest in optoelectronic device applications, high energy Rutherford backscattering spectrometry and ion channeling (RBS-C) must be used. Presented here are the Er depth profile and lattice damage results obtained from 5 MeV RBS-C measurements on samples of LiNbO{sub 3} implanted with various doses of MeV Erbium and subsequently thermally annealed at a temperature of 1000 deg C. It was found that there is a peak implant concentration (2 x 10{sup 16} Er/cm{sup 2}) for which erbium no longer goes substitutional in the lattice, and the implantation damage is not fully removed by annealing. 8 refs., 3 figs.

  12. A comprehensive study on energy absorption and exposure buildup factors for some essential amino acids, fatty acids and carbohydrates in the energy range 0.015-15 MeV up to 40 mean free path

    Energy Technology Data Exchange (ETDEWEB)

    Kurudirek, Murat, E-mail: mkurudirek@gmail.com; Ozdemir, Yueksel

    2011-01-01

    The gamma ray energy absorption (EABF) and exposure buildup factors (EBF) have been calculated for some essential amino acids, fatty acids and carbohydrates in the energy region 0.015-15 MeV up to a penetration depth of 40 mfp (mean free path). The five parameter geometric progression (G-P) fitting approximation has been used to calculate both EABF and EBF. Variations of EABF and EBF with incident photon energy, penetration depth and weight fraction of elements have been studied. While the significant variations in EABF and EBF for amino acids and fatty acids have been observed at the intermediate energy region where Compton scattering is the main photon interaction process, the values of EABF and EBF appear to be almost the same for all carbohydrates in the continuous energy region. It has been observed that the fatty acids have the largest EABF and EBF at 0.08 and 0.1 MeV, respectively, whereas the maximum values of EABF and EBF have been observed for aminoacids and carbohydrates at 0.1 MeV. At the fixed energy of 1.5 MeV, the variation of EABF with penetration depth appears to be independent of the variations in chemical composition of the amino acids, fatty acids and carbohydrates. Significant variations were also observed between EABF and EBF which may be due to the variations in chemical composition of the given materials.

  13. Tomography of photon-added and photon-subtracted states

    NARCIS (Netherlands)

    Bazrafkan, MR; Man'ko, [No Value

    2003-01-01

    The purpose of this paper is to introduce symplectic and optical tomograms of photon-added and photon-subtracted quantum states. Explicit relations for the tomograms of photon-added and photon-subtracted squeezed coherent states and squeezed number states are obtained. Generating functions for the m

  14. Fundamentals of microwave photonics

    CERN Document Server

    Urick, V J; McKinney , Jason D

    2015-01-01

    A comprehensive resource to designing andconstructing analog photonic links capable of high RFperformanceFundamentals of Microwave Photonics provides acomprehensive description of analog optical links from basicprinciples to applications.  The book is organized into fourparts. The first begins with a historical perspective of microwavephotonics, listing the advantages of fiber optic links anddelineating analog vs. digital links. The second section coversbasic principles associated with microwave photonics in both the RFand optical domains.  The third focuses on analog modulationformats-starti

  15. Physics of photonic devices

    CERN Document Server

    Chuang, Shun Lien

    2009-01-01

    The most up-to-date book available on the physics of photonic devices This new edition of Physics of Photonic Devices incorporates significant advancements in the field of photonics that have occurred since publication of the first edition (Physics of Optoelectronic Devices). New topics covered include a brief history of the invention of semiconductor lasers, the Lorentz dipole method and metal plasmas, matrix optics, surface plasma waveguides, optical ring resonators, integrated electroabsorption modulator-lasers, and solar cells. It also introduces exciting new fields of research such as:

  16. Photon collider Higgs factories

    CERN Document Server

    Telnov, V I

    2014-01-01

    The discovery of the Higgs boson (and still nothing else) have triggered appearance of many proposals of Higgs factories for precision measurement of the Higgs properties. Among them there are several projects of photon colliders (PC) without e+e- in addition to PLC based on e+e- linear colliders ILC and CLIC. In this paper, following a brief discussion of Higgs factories physics program I give an overview of photon colliders based on linear colliders ILC and CLIC, and of the recently proposed photon-collider Higgs factories with no e+e- collision option based on recirculation linacs in ring tunnels.

  17. Single photon quantum cryptography.

    Science.gov (United States)

    Beveratos, Alexios; Brouri, Rosa; Gacoin, Thierry; Villing, André; Poizat, Jean-Philippe; Grangier, Philippe

    2002-10-28

    We report the full implementation of a quantum cryptography protocol using a stream of single photon pulses generated by a stable and efficient source operating at room temperature. The single photon pulses are emitted on demand by a single nitrogen-vacancy color center in a diamond nanocrystal. The quantum bit error rate is less that 4.6% and the secure bit rate is 7700 bits/s. The overall performances of our system reaches a domain where single photons have a measurable advantage over an equivalent system based on attenuated light pulses.

  18. Photonics: Technology project summary

    Science.gov (United States)

    Depaula, Ramon P.

    1991-01-01

    Photonics involves the use of light (photons) in conjunction with electronics for applications in communications, computing, control, and sensing. Components used in photonic systems include lasers, optical detectors, optical wave guide devices, fiber optics, and traditional electronic devices. The goal of this program is to develop hybrid optoelectronic devices and systems for sensing, information processing, communications, and control. It is hoped that these new devices will yield at least an order of magnitude improvement in performance over existing technology. The objective of the program is to conduct research and development in the following areas: (1) materials and devices; (2) networking and computing; (3) optical processing/advanced pattern recognition; and (4) sensing.

  19. (π+/-,π+/-p) reaction at 245 MeV

    Science.gov (United States)

    Piasetzky, E.; Ashery, D.; Altman, A.; Yavin, A. I.; Schlepütz, F. W.; Powers, R. J.; Bertl, W.; Felawka, L.; Walter, H. K.; Winter, R. G.; Pluym, J. V. D.

    1982-05-01

    The inclusive (π+/-,π+/-p) reactions on C, Fe, and Bi were studied at 245 MeV in a broad kinematic range by means of coincidence measurement of the outgoing particles. The π-p angular correlations and proton-energy spectra show features consistent with those expected from quasifree scattering. It is observed that about 80% of the inclusive inelastic scattering cross section at backward pion angles may be attributed to nucleon knockout mechanisms. The results allow identification of the direct quasifree process, unperturbed by higher order effects, which accounts for 30%, 20%, and 15% of the C, Fe, and Bi inclusive (π+,π+) differential cross sections, respectively. The ratio of positive to negative pion cross sections for quasifree scattering, integrated over the proton energy and angle, are in agreement with the ratio for free π-p scattering. Such is not the case for various proton angles. The deviation of the positive to negative ratio at the peak of the proton angular correlation from the free scattering ratio is most pronounced for more forward pion angles. NUCLEAR REACTIONS (π+/-,π+/-p) coin. measurements on C, Fe, Bi, E=245 MeV; deduced σknockout decomposition of σinelastic.

  20. Limitations of 14 MeV neutron simulation techniques

    Science.gov (United States)

    Kley, W.; Bishop, G. R.; Sinha, A.

    1988-07-01

    A D-T fusion cycle produces five times more neutrons per unit of energy released than a fission cycle, with about twice the damage energy and the capability to produce ten times more hydrogen, helium and transmutation products than fission neutrons. They determine, together with other parameters, the lifetime of the construction materials for the low plasma-density fusion reactors (tokamak, tandem-mirror, etc.), which require a first wall. For the economie feasibility of fusion power reactors the first wall and blanket materials must withstand a dose approaching 300 to 400 dpa. Arguments are presented that demonstrate that today's simulation techniques using existing fission reactors and charged particle beams are excellent tools to study the underlying basic physical phenomena of the evolving damage structures but are not sufficient to provide a valid technological data base for the design of economie fusion power reactors. It is shown than an optimized spallation neutron source based on a continuous beam of 600 MeV, 6 mA protons is suitable to simulate first wall conditions. Comparing it with FMIT the 35 MeV, 100 mA D + -Li neutron source, we arrive at the following figure of merit: FM = {(dpa·volume) EURAC}/{(dpa·volume) FMIT} = {} = 111 reflecting the fact that the proton beam generates about 100 times more neutrons than the deuteron beam in FMIT for the same beam power.

  1. Angular spreading measurements using MeV ion microscopes

    Energy Technology Data Exchange (ETDEWEB)

    Whitlow, Harry J., E-mail: harry.whitlow@he-arc.ch [Institut des Microtechnologies Appliquées, Haute Ecole Arc Ingénierie, Eplatures-Gris 17, CH-2300 La Chaux-de-Fonds (Switzerland); Department of Physics, P.O. Box 35 (YFL), FI-40014 University of Jyväskylä (Finland); Ren, Minqin; Chen, Xiao; Osipowicz, Thomas; Kan, Jeroen A. van; Watt, Frank [Centre for Ion Beam Applications, National University of Singapore (Singapore)

    2013-07-01

    The sharpness of MeV ion microscope images is governed by small-angle scattering and associated lateral spreading of the ion beam in the sample. We have investigated measurement of the half-angle of the angular spreading distribution by characterising the image blurring in direct-Scanning Transmission Ion Microscopy (direct-STIM). In these tests Mylar™ foils of 0.5–6 μm were used to induce angular spreading. Images were taken of an electron microscope grid using 2 MeV protons with, and without, the foils in the beam path. The blurring was measured by fitting the width of a circular Gaussian point spread function to the images with and without the foil in position. The results show the half-angle width of the spreading has a square root dependence on foil thickness that lies intermediate between SRIM predictions and the theoretical estimates (Bird and Williams fits to the Sigmund and Winterbon data and Amsel et al.)

  2. Characteristic parameters of 6--21 MeV electron beams from a 21 MeV linear accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Al-Ghazi, M.S.A.L. (Department of Medical Physics, Thunder Bay Regional Cancer Centre, Ontario Cancer Treatment and Research Foundation, Thunder Bay, Ontario P7A 7T1, (Canada) Department of Physics, Lakehead University, Thunder Bay, Ontario P7B 5E1, (Canada) Lingman, D. Department of Medical Physics, Thunder Bay Regional Cancer Centre, Ontario Cancer Treatment and Research Foundation, Thunder Bay, Ontario P7A 7T1, (Canada) Department of Computer Science, Lakehead University, Thunder Bay, Ontario P7B 5E1, (Canada)); Gilbert, L.D. (Thekkumthala, J. Department of Medical Physics, Thunder Bay Regional Cancer Centre, Ontario Cancer Treatment and Research Foundation, Thunder Bay, Ontario P7A 7T1, (Canada))

    1991-07-01

    Dosimetry measurements have been carried out for the electron beams produced by a linear accelerator at energies 6, 8, 10, 14, 18, and 21 MeV. Characteristic parameters of the central axis dose distributions were derived and compared to corresponding values of electron beams from other accelerators in clinical use where such a comparison is appropriate. A comprehensive set of dosimetric parameters is provided for electron beam treatment planning. The data include central axis depth dose, range--energy parameters, beam penumbra and uniformity.

  3. Observational Possibility of the Early GRBs using a Gaseous Electron Tracking Compton Camera in sub-MeV and MeV regions

    Science.gov (United States)

    Tanimori, Toru

    2010-10-01

    GRBs have been recently known as a unique probe to catch the highest z galaxies and stars. Here I propose the new trigger method to catch high-z GRBs with z>10 efficiently by imaging sub-MeV gamma rays from GRBs. We have developed the Electron Tracking Compton Camera (ETCC) with reconstructing tracks of the recoil electron in Compton process to explore the MeV gamma-ray astronomy. By measuring the track of a recoil electron, the direction of the incident gamma ray is determined for each photon, which enables us to reconstruct the direction of GRBs by detecting only several ten photons (>100 keV). Ability of the large ETCC (100 cm2 effective area) to detect GRBs with z~20 is revealed, based on the results of the balloon experiment and laboratory imaging test using the small ETCC.

  4. Shielding data for 100 250 MeV proton accelerators: Attenuation of secondary radiation in thick iron and concrete/iron shields

    Science.gov (United States)

    Agosteo, S.; Magistris, M.; Mereghetti, A.; Silari, M.; Zajacova, Z.

    2008-08-01

    Double differential distributions of neutrons produced by 100, 150, 200 and 250 MeV protons stopped in a thick iron target were calculated with the FLUKA Monte Carlo code at four emission angles: forward, 45°, transverse and 135° backwards. The attenuation in thick iron shields of the dose equivalent due to neutrons, protons, photons and electrons was also calculated. The contribution to the total ambient dose equivalent from photons and protons is limited to a few percent at maximum. Source terms and attenuation lengths are given as a function of energy and emission angle, along with fits to the Monte Carlo data, for shallow depth and deep penetration in the shield. A brief discussion of simulations performed with composite iron/concrete shields is also given, showing the need for further investigations.

  5. Effect of polarization entanglement in photon-photon scattering

    Science.gov (United States)

    Rätzel, Dennis; Wilkens, Martin; Menzel, Ralf

    2017-01-01

    It is found that the differential cross section of photon-photon scattering is a function of the degree of polarization entanglement of the two-photon state. A reduced general expression for the differential cross section of photon-photon scattering is derived by applying simple symmetry arguments. An explicit expression is obtained for the example of photon-photon scattering due to virtual electron-positron pairs in quantum electrodynamics. It is shown how the effect in this explicit example can be explained as an effect of quantum interference and that it fits with the idea of distance-dependent forces.

  6. Microwave background constraints on mixing of photons with hidden photons

    Energy Technology Data Exchange (ETDEWEB)

    Mirizzi, Alessandro [Max-Planck-Institut fuer Physik, Muenchen (Germany); Redondo, Javier [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Sigl, Guenter [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik

    2008-12-15

    Various extensions of the Standard Model predict the existence of hidden photons kinetically mixing with the ordinary photon. This mixing leads to oscillations between photons and hidden photons, analogous to the observed oscillations between different neutrino flavors. In this context, we derive new bounds on the photon-hidden photon mixing parameters using the high precision cosmic microwave background spectral data collected by the Far Infrared Absolute Spectrophotometer instrument on board of the Cosmic Background Explorer. Requiring the distortions of the CMB induced by the photon-hidden photon mixing to be smaller than experimental upper limits, this leads to a bound on the mixing angle {chi}{sub 0}

  7. Time-Dependent Neutron and Photon Dose-Field Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Wooten, Hasani Omar [Georgia Inst. of Technology, Atlanta, GA (United States)

    2005-08-01

    A unique tool is developed that allows the user to model physical representations of complicated glovebox facilities in two dimensions and determine neutral-particle flux and ambient dose-equivalent fields throughout that geometry. The Pandemonium code, originally designed to determine flux and dose-rates only, is improved to include realistic glovebox geometries, time-dependent source and detector positions, time-dependent shielding thickness calculations, time-integrated doses, a representative criticality accident scenario based on time-dependent reactor kinetics, and more rigorous photon treatment. A primary benefit of this work has been an extensive analysis and improvement of the photon model that is not limited to the application described in this thesis. The photon model has been extended in energy range to 10 MeV to include photons from fission and new photon buildup factors have been included that account for the effects of photon buildup at slant-path thicknesses as a function of angle, where the mean free path thickness has been preserved. The overall system of codes is user-friendly and it is directly applicable to facilities such as the plutonium facility at Los Alamos National Laboratory, where high-intensity neutron and photon emitters are regularly used. The codes may be used to determine a priori doses for given work scenarios in an effort to supply dose information to process models which will in turn assist decision makers on ensuring as low as reasonably achievable (ALARA) compliance. In addition, coupling the computational results of these tools with the process model visualization tools will help to increase worker safety and radiological safety awareness.

  8. The DHG sum rule measured with medium energy photons

    Energy Technology Data Exchange (ETDEWEB)

    Hicks, K.; Ardashev, K. [Ohio Univ., Athens, OH (United States); Babusci, D. [INFN-Lab. Nazionali di Frascati (Italy)] [and others

    1997-12-31

    The structure of the nucleon has many important features that are yet to be uncovered. Of current interest is the nucleon spin-structure which can be measured by doing double-polarization experiments with photon beams of medium energies (0.1 to 2 GeV). One such experiment uses dispersion relations, applied to the Compton scattering amplitude, to relate measurement of the total reaction cross section integrated over the incident photon energy to the nucleon anomalous magnetic moment. At present, no single facility spans the entire range of photon energies necessary to test this sum rule. The Laser-Electron Gamma Source (LEGS) facility will measure the double-polarization observables at photon energies between 0.15--0.47 MeV. Either the SPring8 facility, the GRAAL facility (France), or Jefferson Laboratory could make similar measurements at higher photon energies. A high-precision measurement of the spin-polarizability and the Drell-Hearn-Gerasimov sum rule is now possible with the advent of high-polarization solid HD targets at medium energy polarized photon facilities such as LEGS, GRAAL and SPring8. Other facilities with lower polarization in either the photon beam or target (or both) are also pursuing these measurements because of the high priority associated with this physics. The Spin-asymmetry (SASY) detector that will be used at LEGS has been briefly outlined in this paper. The detector efficiencies have been explored with simulations studies using the GEANT software, with the result that both charged and uncharged pions can be detected with a reasonable efficiency (> 30%) over a large solid angle. Tracking with a TPC, which will be built at LEGS over the next few years, will improve the capabilities of these measurements.

  9. A bismuth activation counter for high sensitivity pulsed 14 MeV neutrons

    Science.gov (United States)

    Burns, E. J. T.; Thacher, P. D.; Hassig, G. J.; Decker, R. D.; Romero, J. A.; Barrett, K. P.

    2011-08-01

    We have built a fast neutron bismuth activation counter that measures activation counts from pulsed 14-MeV neutron generators for incident neutron fluences between 30 and 300 neutrons/cm2 at 15.2 cm (6 in.). The activation counter consists of a large bismuth germanate (BGO) detector surrounded by a bismuth metal shield in front of and concentric with the cylindrical detector housing. The 14 MeV neutrons activate the 2.6-millisecond (ms) isomer in the shield and the detector by the reaction 209Bi (n,2nγ) 208mBi. The use of millisecond isomers and activation counting times minimizes the background from other activated materials and the environment. In addition to activation, the bismuth metal shields against other outside radiation sources. We have tested the bismuth activation counter, simultaneously, with two data acquisition systems (DASs) and both give similar results. The two-dimensional (2D) DAS and three dimensional (3D) DAS both consist of pulse height analysis (PHA) systems that can be used to discriminate against gamma radiations below 300 keV photon energy, so that the detector can be used strictly as a counter. If the counting time is restricted to less than 25 ms after the neutron pulse, there are less than 10 counts of background for single pulse operation in all our operational environments tested so far. High-fluence neutron generator operations are restricted by large dead times and pulse height saturation. When we operate our 3D DAS PHA system in list mode acquisition (LIST), real-time corrections to dead time or live time can be made on the scale of 1 ms time windows or dwell times. The live time correction is consistent with nonparalyzable models for dead time of 1.0±0.2 μs for our 3D DAS and 1.5±0.3 μs for our 2D DAS dominated by our fixed time width analog to digital converters (ADCs). With the same solid angle, we have shown that the bismuth activation counter has a factor of 4 increase in sensitivity over our lead activation counter

  10. Design of Tunable Anisotropic Photonic Crystal Filter as Photonic Switch

    OpenAIRE

    Majid Seifan; Alireza Malekijavan; Alireza Monajati Kashani

    2014-01-01

    By creating point defects and line defects in photonic crystals, we reach the new sort of photonic crystals. Which allow us to design photonic crystals filters. In this type of photonic crystals the ability to tune up central frequency of filter is important to attention. In this paper, we use foregoing points for designing photonic crystal filters. The main function of this type of filters is coupling between shield of point defect modes and directional line defect modes. By using liquid cry...

  11. Photon Polarization in Photonic Crystal Fibers under Compton Scattering

    Institute of Scientific and Technical Information of China (English)

    HAO Dong-shan; ZHANG Xiao-fu

    2007-01-01

    Using the quantum invariant theory and unitary transformation means, we study the influences of multi-photon nonlinear Compton scattering on the photon polarization in photonic crystal fibers(PCF). The results show that the photon polarization of the incident photon changes a lot due to scattered optical, and its general geometric phase factor, Hamiton number and evolution operator are definited both by the incident and scattered optical.

  12. Two-phonon 1- state in 112Sn observed in resonant photon scattering

    CERN Document Server

    Pysmenetska, I; Karg, O; Kneissl, U; Kohstall, C; Pitz, H H; Ponomarev, V Yu; Scheck, M; Stedile, F; Volz, S; Von Neumann-Cosel, P; Walter, S; Von Garrel, H

    2006-01-01

    Results of a photon scattering experiment on 112Sn using bremsstrahlung with an endpoint energy of E_0 = 3.8 MeV are reported. A J = 1 state at E_x = 3434(1) keV has been excited. Its decay width into the ground state amounts to Gamma_0 = 151(17) meV, making it a candidate for a [2+ x 3-]1- two-phonon state. The results for 112Sn are compared with quasiparticle-phonon model calculations as well as the systematics of the lowest-lying 1- states established in other even-mass tin isotopes. Contrary to findings in the heavier stable even-mass Sn isotopes, no 2+ states between 2 and 3.5 MeV excitation energy have been detected in the present experiment.

  13. Cosmological Constraints on Decoupled Dark Photons and Dark Higgs

    Energy Technology Data Exchange (ETDEWEB)

    Berger, Joshua [Univ. of Wisconsin, Madison, WI (United States); Jedamzik, Karsten [Univ. Montpellier II (France). Lab. Univers. et Particules de Monpellier; Walker, Devin G.E. [Univ. of Washington, Seattle, WA (United States). Dept. of Physics

    2016-05-23

    Any neutral boson such as a dark photon or dark Higgs that is part of a non-standard sector of particles can mix with its standard model counterpart. When very weakly mixed with the Standard Model, these particles are produced in the early Universe via the freeze-in mechanism and subsequently decay back to standard model particles. In this work, we place constraints on such mediator decays by considering bounds from Big Bang nucleosynthesis and the cosmic microwave background radiation. We find both nucleosynthesis and CMB can constrain dark photons with a kinetic mixing parameter between log ϵ ~ -10 to -17 for masses between 1 MeV and 100 GeV. Similarly, the dark Higgs mixing angle ϵ with the Standard Model Higgs is constrained between log ϵ ~ -6 to -15. Dramatic improvement on the bounds from CMB spectral distortions can be achieved with proposed experiments such as PIXIE.

  14. Cosmological constraints on decoupled dark photons and dark Higgs

    Science.gov (United States)

    Berger, Joshua; Jedamzik, Karsten; Walker, Devin G. E.

    2016-11-01

    Any neutral boson such as a dark photon or dark Higgs that is part of a non-standard sector of particles can mix with its standard model counterpart. When very weakly mixed with the Standard Model, these particles are produced in the early Universe via the freeze-in mechanism and subsequently decay back to standard model particles. In this work, we place constraints on such mediator decays by considering bounds from Big Bang nucleosynthesis and the cosmic microwave background radiation. We find both nucleosynthesis and CMB can constrain dark photons with a kinetic mixing parameter between log epsilon ~ -10 to -17 for masses between 1 MeV and 100 GeV . Similarly, the dark Higgs mixing angle epsilon with the Standard Model Higgs is constrained between log epsilon ~ -6 to -15. Dramatic improvement on the bounds from CMB spectral distortions can be achieved with proposed experiments such as PIXIE.

  15. Cosmological constraints on decoupled dark photons and dark Higgs

    Energy Technology Data Exchange (ETDEWEB)

    Berger, Joshua [Physics Department, University of Wisconsin-Madison,1150 University Ave, Madison, WI 53706 (United States); Jedamzik, Karsten [Laboratoire Univers et Particules de Montpellier, UMR5299-CNRS,Université Montpellier II,Place Eugène Bataillon, CC 72, 34095 Montpellier Cédex 05 (France); Walker, Devin G.E. [Department of Physics and Astronomy, Dartmouth College,6127 Wilder Laboratory, Hanover, NH 03755 (United States); Department of Physics, University of Washington,Box 351560, Seattle, WA 98195 (United States)

    2016-11-16

    Any neutral boson such as a dark photon or dark Higgs that is part of a non-standard sector of particles can mix with its standard model counterpart. When very weakly mixed with the Standard Model, these particles are produced in the early Universe via the freeze-in mechanism and subsequently decay back to standard model particles. In this work, we place constraints on such mediator decays by considering bounds from Big Bang nucleosynthesis and the cosmic microwave background radiation. We find both nucleosynthesis and CMB can constrain dark photons with a kinetic mixing parameter between log ϵ∼−10 to −17 for masses between 1 MeV and 100 GeV. Similarly, the dark Higgs mixing angle ϵ with the Standard Model Higgs is constrained between log ϵ∼−6 to −15. Dramatic improvement on the bounds from CMB spectral distortions can be achieved with proposed experiments such as PIXIE.

  16. Scoping studies - photon and low energy neutron interrogation

    Energy Technology Data Exchange (ETDEWEB)

    Becker, G.; Harker, Y.; Jones, J. [LMITCo, Idaho Falls, ID (United States); Harmon, F. [Idaho State Univ., Pocatello, ID (United States)

    1997-11-01

    High energy photon interrogation of waste containers, with the aim of producing photo nuclear reactions, in specific materials, holds the potential of good penetration and rapid analysis. Compact high energy ({le} 10 MeV) photon sources in the form of electron linacs producing bremstrahlung radiation are readily available. Work with the Varitron variable energy accelerator at ISU will be described. Advantages and limitations of the technique will be discussed. Using positive ion induced neutron producing reactions, it is possible to generate neutrons in a specific energy range. By this means, variable penetration and specific reactions can be excited in the assayed material. Examples using the {sup 3}H(p,n) and {sup 7}Li(p,n) reactions as neutron sources will be discussed. 4 refs., 7 figs.

  17. What is a photon?

    CERN Document Server

    Natarajan, Vasant

    2013-01-01

    We discuss the absorber theory of radiation as put forward by Wheeler and Feynman. We show that it gives a better understanding of the photon compared to the usual quantum electrodynamics (QED) picture.

  18. Nonlinear optics and photonics

    CERN Document Server

    He, Guang S

    2015-01-01

    This book provides a comprehensive presentation on most of the major topics in nonlinear optics and photonics, with equal emphasis on principles, experiments, techniques, and applications. It covers many major new topics including optical solitons, multi-photon effects, nonlinear photoelectric effects, fast and slow light , and Terahertz photonics. Chapters 1-10 present the fundamentals of modern nonlinear optics, and could be used as a textbook with problems provided at the end of each chapter. Chapters 11-17 cover the more advanced topics of techniques and applications of nonlinear optics and photonics, serving as a highly informative reference for researchers and experts working in related areas. There are also 16 pages of color photographs to illustrate the visual appearances of some typical nonlinear optical effects and phenomena. The book could be adopted as a textbook for both undergraduates and graduate students, and serve as a useful reference work for researchers and experts in the fields of physics...

  19. Principles of photonics

    CERN Document Server

    Liu, Jia-Ming

    2016-01-01

    With this self-contained and comprehensive text, students will gain a detailed understanding of the fundamental concepts and major principles of photonics. Assuming only a basic background in optics, readers are guided through key topics such as the nature of optical fields, the properties of optical materials, and the principles of major photonic functions regarding the generation, propagation, coupling, interference, amplification, modulation, and detection of optical waves or signals. Numerous examples and problems are provided throughout to enhance understanding, and a solutions manual containing detailed solutions and explanations is available online for instructors. This is the ideal resource for electrical engineering and physics undergraduates taking introductory, single-semester or single-quarter courses in photonics, providing them with the knowledge and skills needed to progress to more advanced courses on photonic devices, systems and applications.

  20. Detection efficiency calculation for photons, electrons and positrons in a well detector. Part II: Analytical model versus simulations

    Energy Technology Data Exchange (ETDEWEB)

    Pomme, S. [European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, Retieseweg 111, B-2440 Geel (Belgium)], E-mail: stefaan.pomme@ec.europa.eu; Sibbens, G.; Vidmar, T. [European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, Retieseweg 111, B-2440 Geel (Belgium); Camps, J. [European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, Retieseweg 111, B-2440 Geel (Belgium); SCK.CEN, Belgian Nuclear Research Centre, Boeretang 200, B-2400 Mol (Belgium); Peyres, V. [Laboratorio de Metrologia de Radiaciones Ionizantes, Ed. 12, CIEMAT, Avda. Complutense 22, 28040 Madrid (Spain)

    2009-07-21

    A comparison is made between the results of Monte Carlo simulations and a new analytical model (cf. Part I) for the detection efficiency of a well-type NaI detector for photons, electrons and positrons in the energy range of 0.01 MeV-10 MeV. Using MCNP 5.1.40, GEANT3 and PENELOPE simulation results as benchmark, it was found that the analytical model was quite successful at reproducing the total detection efficiency for photons and positrons, and at giving rough indications on the photon peak-to-total ratio and the electron detection efficiency. It was also able to deal with cylindrical volume sources and vials, eccentric positioning of the source inside the detector well and the possible contribution of scattering or pair production in the surrounding lead shield.

  1. Photonic bandgap structures

    CERN Document Server

    Marco, Pisco; Antonello, Cutolo

    2012-01-01

    This E-Book covers the research and the development of a novel generation of photonic devices for sensing applications. Key features of this book include a brief review of basic PhCs related design and fabrication concepts, a selection of crossover topics for the development of novel technological platforms for physical, chemical and biological sensing and a description of the main PhCs sensors to date by representing many of the exciting sensing applications that utilize photonic crystal structures.

  2. Photonics in switching

    CERN Document Server

    Midwinter, John E; Kelley, Paul

    1993-01-01

    Photonics in Switching provides a broad, balanced overview of the use of optics or photonics in switching, from materials and devices to system architecture. The chapters, each written by an expert in the field, survey the key technologies, setting them in context and highlighting their benefits and possible applications. This book is a valuable resource for those working in the communications industry, either at the professional or student level, who do not have extensive background knowledge or the underlying physics of the technology.

  3. Photonic Bandgap Fibers

    DEFF Research Database (Denmark)

    Barkou, Stig Eigil; Broeng, Jes; Bjarklev, Anders Overgaard

    1999-01-01

    Photonic bandgap fibers are describes using a new Kagomé cladding structure. These fibers may potentially guide light in low-index regions. Such fibers offer new dispersion properties, and large design flexibility.......Photonic bandgap fibers are describes using a new Kagomé cladding structure. These fibers may potentially guide light in low-index regions. Such fibers offer new dispersion properties, and large design flexibility....

  4. ALICE photon spectrometer crystals

    CERN Multimedia

    Maximilien Brice

    2006-01-01

    Members of the mechanical assembly team insert the last few crystals into the first module of ALICE's photon spectrometer. These crystals are made from lead-tungstate, a crystal as clear as glass but with nearly four times the density. When a high-energy particle passes through one of these crystals it will scintillate, emitting a flash of light allowing the energy of photons, electrons and positrons to be measured.

  5. Ultrastable Multigigahertz Photonic Oscillator

    Science.gov (United States)

    Logan, Ronald T., Jr.

    1996-01-01

    Novel photonic oscillator developed to serve as ultrastable source of microwave and millimeter-wave signals. In system, oscillations generated photonically, then converted to electronic form. Includes self-mode-locked semiconductor laser producing stream of pulses, detected and fed back to laser as input. System also includes fiber-optic-delay-line discriminator, which detects fluctuations of self-mode-locking frequency and generates error signal used in negative-feedback loop to stabilize pulse-repetition frequency.

  6. QUANTUM CRYPTOGRAPHY: Single Photons.

    Science.gov (United States)

    Benjamin, S

    2000-12-22

    Quantum cryptography offers the potential of totally secure transfer of information, but as Benjamin discusses in this Perspective, its practical implementation hinges on being able to generate single photons (rather than two or more) at a time. Michler et al. show how this condition can be met in a quantum dot microdisk structure. Single molecules were also recently shown to allow controlled single-photon emission.

  7. Scattering and absorption differential cross sections for double photon Compton scattering

    Indian Academy of Sciences (India)

    B S Sandhu; M B Saddi; B Singh; B S Ghumman

    2001-10-01

    The scattering and absorption differential cross sections for nonlinear QED process such as double photon Compton scattering have been measured as a function of independent final photon energy. The incident gamma photons are of 0.662 MeV in energy as produced by an 8 Ci137Cs radioactive source and thin aluminum foils are used as scatterer. The two simultaneously emitted photons in this process are detected in coincidence using two NaI(T1) scintillation detectors and a slow-fast coincidence set-up of 30 nsec resolving time. The measured values of scattering and absorption differential cross sections agree with theory within experimental estimated error.

  8. Photon yields from nitrogen gas and dry air excited by electrons

    CERN Document Server

    Nagano, M; Sakaki, N; Ando, K

    2003-01-01

    In order to detect ultrahigh-energy cosmic rays (UHECR), atmospheric fluorescence light from the trajectory of the extensive air shower may be measured by mirror-photosensor systems. In this type of experiment the photon yield from electrons exciting air of various densities and temperatures is most fundamental information for estimating the primary energy of UHECR. An experiment has been undertaken using a Sr90 $\\beta$ source to study the pressure dependence of photon yields, and the life times of the excited states, for radiation in nitrogen and dry air. The photon yield between 300 nm and 406 nm in air excited by 0.85 MeV electrons is 3.734+-0.148 (+-13.2 % systematic) photons per meter at 1000 hPa and 20 $^{\\circ}$C. The air density and temperature dependence is given for application to UHECR observations.

  9. A photon observed by the SEDA-FIB detector on the arrival of the gravitational wave

    CERN Document Server

    Muraki, Y; Koga, K; Matsumoto, H; Shibata, S

    2016-01-01

    We reported a photon detection at the arrival time of the gravitational wave on December 26th, 2015. According to the LIGO-Virgo collaboration, the gravitational wave was produced by the merging process of the two black holes. The merged time was determined at 03:38:53.6 UT on December 26th. At 03:38:54.05 GPS time, one of the detectors of SEDA-FIB on board the International Space Station (ISS) detected a photon, arriving from the direction of Corona Australis near the Galactic Bulge (GB). The energy of the photon was about (35+-7) MeV. A 3.0 sigma level detection of the photon is discussed.

  10. Bremsstrahlung photons - an ideal tool in nuclear structure and nuclear astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Babilon, Mario [Institut fur Kernphysik, Darmstadt (Germany)

    2005-07-01

    Full text of publication follows. Bremsstrahlung photons, produced by decelerating electrons, are a very useful probe to investigate current topics in nuclear structure and nuclear astrophysics. The photon scattering facility of the superconducting electron accelerator S-DALINAC at the Darmstadt University of Technology allows for high resolution Nuclear Resonance Fluorescence (NRF) experiments up to 10 MeV. One current topic of interest in nuclear structure is the investigation of Pygmy Dipole Resonances (PDR), which are located near the particle threshold. Recently, experiments have been carried out on Ca isotopes [1] as well as on several N=82 nuclei [2] in order to understand the structure of the PDR. Moreover, important astrophysical questions can be investigated using real photons (g,n) reaction rates, which play a major role in nucleosynthesis, can be measured at the S-DALINAC by simulating a quasi-stellar photon bath with variable temperature [3,4].

  11. Comparative evaluation of photon cross section libraries for materials of interest in PET Monte Carlo simulations

    CERN Document Server

    Zaidi, H

    1999-01-01

    the many applications of Monte Carlo modelling in nuclear medicine imaging make it desirable to increase the accuracy and computational speed of Monte Carlo codes. The accuracy of Monte Carlo simulations strongly depends on the accuracy in the probability functions and thus on the cross section libraries used for photon transport calculations. A comparison between different photon cross section libraries and parametrizations implemented in Monte Carlo simulation packages developed for positron emission tomography and the most recent Evaluated Photon Data Library (EPDL97) developed by the Lawrence Livermore National Laboratory was performed for several human tissues and common detector materials for energies from 1 keV to 1 MeV. Different photon cross section libraries and parametrizations show quite large variations as compared to the EPDL97 coefficients. This latter library is more accurate and was carefully designed in the form of look-up tables providing efficient data storage, access, and management. Toge...

  12. Constraining nuclear photon strength functions by the decay properties of photo-excited states

    Energy Technology Data Exchange (ETDEWEB)

    Isaak, J., E-mail: j.isaak@gsi.de [ExtreMe Matter Institute EMMI and Research Division, GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Frankfurt Institute for Advanced Studies FIAS, 60438 Frankfurt (Germany); Savran, D. [ExtreMe Matter Institute EMMI and Research Division, GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Frankfurt Institute for Advanced Studies FIAS, 60438 Frankfurt (Germany); Krtička, M. [Faculty of Mathematics and Physics, Charles University, Prague 8 (Czech Republic); Ahmed, M.W. [Department of Mathematics and Physics, North Carolina Central University, Durham, NC 27707 (United States); Department of Physics, Duke University, Durham, NC 27708 (United States); Triangle Universities Nuclear Laboratory, Durham, NC 27708 (United States); Beller, J. [Institut für Kernphysik, Technische Universität Darmstadt, 64289 Darmstadt (Germany); Fiori, E. [ExtreMe Matter Institute EMMI and Research Division, GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Frankfurt Institute for Advanced Studies FIAS, 60438 Frankfurt (Germany); Glorius, J. [Institut für Angewandte Physik, Goethe-Universität Frankfurt, 60438 Frankfurt (Germany); Kelley, J.H. [Department of Physics, North Carolina State University, Raleigh, NC 27695 (United States); Triangle Universities Nuclear Laboratory, Durham, NC 27708 (United States); Löher, B. [ExtreMe Matter Institute EMMI and Research Division, GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Frankfurt Institute for Advanced Studies FIAS, 60438 Frankfurt (Germany); and others

    2013-12-18

    A new approach for constraining the low-energy part of the electric dipole Photon Strength Function (E1-PSF) is presented. Experiments at the Darmstadt High-Intensity Photon Setup and the High Intensity γ{sup →}-Ray Source have been performed to investigate the decay properties of {sup 130}Te between 5.50 and 8.15 MeV excitation energy. In particular, the average γ-ray branching ratio to the ground state and the population intensity of low-lying excited states have been studied. A comparison to the statistical model shows that the latter is sensitive to the low-energy behavior of the E1-PSF, while the average ground state branching ratio cannot be described by the statistical model in the energy range between 5.5 and 6.5 MeV.

  13. The test of the LKr calorimeter prototype at the tagged photon beam

    Energy Technology Data Exchange (ETDEWEB)

    Aulchenko, V.M. [Rossijskaya Akademiya Nauk, Novosibirsk (Russian Federation). Inst. Yadernoj Fiziki; Bondar, A.E. [Rossijskaya Akademiya Nauk, Novosibirsk (Russian Federation). Inst. Yadernoj Fiziki; Cantoni, P.; Frabetti, P.L.; Ganzhur, S.F.; Kezerashvili, G.Ya.; Klimenko, S.G.; Lanni, F.; Leontiev, L.A.; Maggi, B.; Malyshev, V.M.; Maslennikov, A.L.; Manfredi, P.F.; Milov, A.M.; Muchnoi, N.Yu.; Onuchin, A.P.; Palombo, F.; Panin, V.S.; Peleganchuk, S.V.; Pogorelov, Yu.A.; Pospelov, G.E.; Protopopov, I.Ya.; Re, V.; Sala, A.; Shamov, A.G.; Shatilov, D.N.; Simonov, E.A.; Speziali, V.; Stagni, L.; Tikhonov, Yu.A.

    1997-07-11

    The experiment with the prototype of liquid krypton electromagnetic calorimeter for the KEDR detector is described. The experiment was carried out at the VEPP-4M collider at the tagged photon beam. The tagged photons were obtained in the energy region 50-625 MeV using the ROKK-1M facility. The edges of the bremsstrahlung spectra were used for the energy resolution measurement in the high-energy region up to 4500 MeV. The energy resolution comparable with the resolution of the best crystal calorimeters and the excellent spatial resolution ({proportional_to}1 mm) have been obtained. The results are in good agreement with the Monte-Carlo simulation. (orig.).

  14. Calculation of energy deposition, photon and neutron production in proton therapy of thyroid gland using MCNPX.

    Science.gov (United States)

    Mowlavi, Ali Asghar; Fornasie, Maria Rosa; de Denaro, Mario

    2011-01-01

    In this study, the MCNPX code has been used to simulate a proton therapy in thyroid gland, in order to calculate the proton energy deposition in the target region. As well as, we have calculated the photon and neutron production spectra due to proton interactions with the tissue. We have considered all the layers of tissue, from the skin to the thyroid gland, and an incident high energy pencil proton beam. The results of the simulation show that the best proton energy interval, to cover completely the thyroid tissue, is from 42 to 54 MeV, assuming that the thyroid gland has a 14 mm thickness and is located 11.2mm under the skin surface. The most percentage of deposited energy (78%) is related to the 54 MeV proton energy beam. Total photon and neutron production are linear and polynomial second order functions of the proton energy, respectively.

  15. Commissioning of a medical accelerator photon beam Monte Carlo simulation using wide-field profiles

    Science.gov (United States)

    Pena, J.; Franco, L.; Gómez, F.; Iglesias, A.; Lobato, R.; Mosquera, J.; Pazos, A.; Pardo, J.; Pombar, M.; Rodríguez, A.; Sendón, J.

    2004-11-01

    A method for commissioning an EGSnrc Monte Carlo simulation of medical linac photon beams through wide-field lateral profiles at moderate depth in a water phantom is presented. Although depth-dose profiles are commonly used for nominal energy determination, our study shows that they are quite insensitive to energy changes below 0.3 MeV (0.6 MeV) for a 6 MV (15 MV) photon beam. Also, the depth-dose profile dependence on beam radius adds an additional uncertainty in their use for tuning nominal energy. Simulated 40 cm × 40 cm lateral profiles at 5 cm depth in a water phantom show greater sensitivity to both nominal energy and radius. Beam parameters could be determined by comparing only these curves with measured data.

  16. Commissioning of a medical accelerator photon beam Monte Carlo simulation using wide-field profiles

    Energy Technology Data Exchange (ETDEWEB)

    Pena, J [Departamento de Fisica de PartIculas, Facultade de Fisica, 15782 Santiago de Compostela (Spain); Franco, L [Departamento de Fisica de PartIculas, Facultade de Fisica, 15782 Santiago de Compostela (Spain); Gomez, F [Departamento de Fisica de PartIculas, Facultade de Fisica, 15782 Santiago de Compostela (Spain); Iglesias, A [Departamento de Fisica de PartIculas, Facultade de Fisica, 15782 Santiago de Compostela (Spain); Lobato, R [Hospital ClInico Universitario de Santiago, Santiago de Compostela (Spain); Mosquera, J [Hospital ClInico Universitario de Santiago, Santiago de Compostela (Spain); Pazos, A [Departamento de Fisica de PartIculas, Facultade de Fisica, 15782 Santiago de Compostela (Spain); Pardo, J [Departamento de Fisica de PartIculas, Facultade de Fisica, 15782 Santiago de Compostela (Spain); Pombar, M [Hospital ClInico Universitario de Santiago, Santiago de Compostela (Spain); RodrIguez, A [Departamento de Fisica de PartIculas, Facultade de Fisica, 15782 Santiago de Compostela (Spain); Sendon, J [Hospital ClInico Universitario de Santiago, Santiago de Compostela (Spain)

    2004-11-07

    A method for commissioning an EGSnrc Monte Carlo simulation of medical linac photon beams through wide-field lateral profiles at moderate depth in a water phantom is presented. Although depth-dose profiles are commonly used for nominal energy determination, our study shows that they are quite insensitive to energy changes below 0.3 MeV (0.6 MeV) for a 6 MV (15 MV) photon beam. Also, the depth-dose profile dependence on beam radius adds an additional uncertainty in their use for tuning nominal energy. Simulated 40 cm x 40 cm lateral profiles at 5 cm depth in a water phantom show greater sensitivity to both nominal energy and radius. Beam parameters could be determined by comparing only these curves with measured data.

  17. Sfermion production at photon colliders

    Energy Technology Data Exchange (ETDEWEB)

    Klasen, M. E-mail: michael.klasen@desy.de

    2001-10-11

    We calculate total and differential cross-sections for sfermion production in e{sup +}e{sup -} annihilation and in photon-photon collisions with arbitrary photon polarization. The total cross-section at a polarized photon collider is shown to be larger than the e{sup +}e{sup -} annihilation cross-section up to the kinematic limit of the photon collider.

  18. Two-photon exchange correction to $2S$-$2P$ splitting in muonic helium

    CERN Document Server

    Carlson, Carl E; Vanderhaeghen, Marc

    2016-01-01

    We calculate the two-photon exchange correction to the Lamb shift in muonic helium atoms within the dispersion relations framework. Part of the effort entailed making analytic fits to the electron-$^3$He quasielastic scattering data set, for purposes of doing the dispersion integrals. Our result is that the energy of the 2$S$ state is shifted downwards by two-photon exchange effects by 15.14(49) meV, in good accord with the result obtained from a potential model and effective field theory calculation.

  19. Photon strength functions studied with the method of two-step cascades

    Science.gov (United States)

    Tomandl, I.; Honzátko, J.; Bečvář, F.; Krtička, M.; Cejnar, P.

    2000-07-01

    The method of two-step γ cascades, following the thermal neutron capture, has proved to be a promising tool for investigation of photon strength functions in the region of transition energies near 3 MeV. Using this method we studied behavior of photon strength functions in 108Ag, 116In, 125Te, 144,146Nd, 150Sm, 156,158Gd, 163Dy and 168Er. Besides the detailed information for individual nuclei a large amount of experimental data allows us to look for general trends in the mass region incorporating spherical, transitional and deformed nuclei. Despite continuing systematic study on other nuclei, some general conclusions could already be done.

  20. Calibration of Cherenkov detectors for monoenergetic photon imaging in active interrogation applications

    Science.gov (United States)

    Rose, P. B.; Erickson, A. S.

    2015-11-01

    Active interrogation of cargo containers using monoenergetic photons offers a rapid and low-dose approach to search for shielded special nuclear materials. Cherenkov detectors can be used for imaging of the cargo provided that gamma ray energies used in interrogation are well resolved, as the case in 11B(d,n-γ)12C reaction resulting in 4.4 MeV and 15.1 MeV photons. While an array of Cherenkov threshold detectors reduces low energy background from scatter while providing the ability of high contrast transmission imaging, thus confirming the presence of high-Z materials, these detectors require a special approach to energy calibration due to the lack of resolution. In this paper, we discuss the utility of Cherenkov detectors for active interrogation with monoenergetic photons as well as the results of computational and experimental studies of their energy calibration. The results of the studies with sources emitting monoenergetic photons as well as complex gamma ray spectrum sources, for example 232Th, show that calibration is possible as long as the energies of photons of interest are distinct.

  1. Determining the focal spot limit of 1 MeV X-ray targets: Monte Carlo simulation of the point spread function

    Science.gov (United States)

    Wang, Jiayue; Shi, Jiaru; Huang, Wenhui; Tang, Chuanxiang

    2017-02-01

    Among all microfocus X-ray tubes, 1 MeV has remained a "gray zone" despite its universal application in radiation therapy and non-destructive testing. One challenge existing in fabricating 1 MeV microfocus X-ray tubes is beam broadening inside metal anodes, which limits the minimum focal spot size a system can obtain. In particular, a complete understanding of the intrinsic broadening process, i.e., the point-spread function (PSF) of X-ray targets is needed. In this paper, relationships between PSF and beam energy, target thickness and electron incidence angle were investigated via Monte Carlo simulation. Focal spot limits for both transmission- and reflection-type tungsten targets at 0.5, 1 and 1.5 MeV were calculated, with target thicknesses ranging from 1 μm to 2 cm. Transmission-type targets with thickness less than 5 μ m could achieve micrometer-scale spots while reflection-type targets exhibited superiority for spots larger than 100 μm . In addition, by demonstrating the spot variation at off-normal incidence, the role of unidirectional beam was explored in microfocus X-ray systems. We expect that these results can enable alternative designs to improve the focal spot limit of X-ray tubes and benefit accurate photon source modeling.

  2. New measurement of γπ/γ for the 0^+2 (7.65 MeV) state in ^12C

    Science.gov (United States)

    Goodman, N. J.; Bos, J.; Lighthall, J. C.; Marley, S. T.; Snyder, J.; Wuosmaa, A. H.; Tur, C.; Austin, Sam M.; Estrada, E.; Lorusso, G.

    2007-10-01

    The rate of ^12C formation through the well known ``triple- alpha'' process is determined by the radiative partial width of the excited 0^+ state at 7.65 MeV in ^12C. Experimentally, the uncertainty in this quantity is determined from the radiative branching ratio, the partial width for e^+e^- decay, and the pair branching ratio. The current uncertainty in the 3-α rate is dominated by that for the e^+e^- branching ratio which is 9.2%. We have performed a new measurement of this quantity aimed at reducing this uncertainty to 5%. 10.4 MeV protons from the Western Michigan University Tandem Van de Graaff accelerator bombarded a 100 μg/cm^2 ^12C target, exciting the 0^+ 7.65 MeV state. Protons were detected at backward angles using two 1 mm thick silicon detectors, and coincident e^+ and e^- were detected with an array of plastic-scintillator detectors where the sensitivity of the device to photons was reduced by dividing the detector into a thick outer block, and thin inner sleeve. The performance of the detector and preliminary results will be discussed. Work supported by the U. S. Department of Energy under contract number DE-FG02-ER41230 (WMU) and the U. S. National Science Foundation, contract numbers PHY06-06007 (MSU) and PHY02-16783 (JINA).

  3. Bremsstrahlung versus Monoenergetic Photon Dose and Photonuclear Stimulation Comparisons At Long Standoff Distances

    Energy Technology Data Exchange (ETDEWEB)

    J. L. Jones; J.W. Sterbentz; W.Y. Yoon

    2009-06-01

    Energetic photon sources with energies greater than 6 MeV continue to be recognized as viable source for various types of inspection applications, especially those related to nuclear and/or explosive material detection. These energetic photons can be produced as a continuum of energies (i.e., bremsstrahlung distribution) or as a set of one or more discrete photon energies (i.e., monoenergetic distribution). This paper will provide a follow-on extension of the photon dose comparison presented at the 9th International Conference on Applications of Nuclear Techniques (June 2008). The latter paper showed the comparative advantages and disadvantages of the photon doses provided by these two energetic interrogation sources and highlighted the higher energy advantage of the bremsstrahlung source, especially at long standoff distances (i.e., distance from source to the inspected object). Specifically, this paper will pursue this higher energy photon inspection advantage (up to 100 MeV) by providing dose and stimulated photonuclear interaction predictions for air and an infinitely dilute interrogated material (used for comparative interaction rate assessments since it excludes material self-shielding) as the interrogation object positioned forward on the inspection beam axis at increasing standoff distances. In addition to the direct energetic photon-induced stimulation, the predictions will identify the importance of any secondary downscattered/attenuated source-term effects arising from the photon transport in the intervening atmosphere. *Supported in part by the Defense Threat Reduction Agency and Department of Energy (DOE) Idaho Operations Office under Contract Number DE-AC07-05ID14517.

  4. Multipole Stack for the 800 MeV PS Booster

    CERN Multimedia

    1975-01-01

    The 800 MeV PS Booster had seen first beam in its 4 superposed rings in 1972, routine operation began in 1973. In the strive for ever higher beam intensities, the need for additional multipole lenses became evident. After detailed studies, the manufacture of 8 stacks of multipoles was launched in 1974. Each stack consists of 4 superposed multipoles and each multipole has 4 concentric shells. From the innermost to the outermost shell, Type A contains octupole, skew-octupole, sextupole, skew-sextupole. Type B contains skew-octupole, skew-sextupole, vertical dipole, horizontal dipole. Completion of installation in 1976 opened the way to higher beam intensities. M. Battiaz is seen here with a multipole stack and its many electrical connections.

  5. Two charmoniumlike charged axial resonances near 3885 MeV

    CERN Document Server

    Voloshin, M B

    2016-01-01

    It is argued that the charged $Z^+_c(3885)$ resonance, treated as a `molecular' state of charmed $D$ and $D^*$ mesons, is likely to consist of two peaks unequally coupled to the $D^{*+} \\bar D^0$ and $D^+ \\bar D^{*0}$ channels. The peaks should be split in mass by at least approximately 1.5 MeV. This behavior arises from an enhancement of the effect of isospin violation in the masses of the $D$ and $D^*$ mesons due to apparent suppression of forces between the mesons depending on the spins of the heavy as well as of the light quarks. The suggested double-peak structure can be studied either by direct shape measurement in the channels with heavy mesons, or by isospin-violating transitions from $Z_c^\\pm(3885)$ to the states of charmonium plus a light meson.

  6. Proton Polarimeter Calibration between 82 and 217 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Glister, J; Lee, B; Beck, A; Brash, E; Camsonne, A; Choi, S; Dumas, J; Feuerbach, R; Gilman, R; Higinbotham, D W; Jiang, X; Jones, M K; May-Tal Beck, S; McCullough, E; Paolone, M; Piasetzky, E; Roche, J; Rousseau, Y; Sarty, A J; Sawatzky, B; Strauch, S

    2009-07-01

    The proton analyzing power in carbon has been measured for energies of 82 to 217 MeV and proton scattering angles of 5 to 41 degrees. The measurements were carried out using polarized protons from the elastic scattering H(pol. e, pol. p) reaction and the Focal Plane Polarimeter (FPP) in Hall A of Jefferson Lab. A new parameterization of the FPP p-C analyzing power was fit to the data, which is in good agreement with previous parameterizations and provides an extension to lower energies and larger angles. The main conclusions are that all polarimeters to date give consistent measurements of the carbon analyzing power, independently of the details of their construction and that measuring on a larger angular range significantly improves the polarimeter figure of merit at low energies.

  7. The 5 MeV bump - a nuclear whodunit mystery

    CERN Document Server

    Huber, Patrick

    2016-01-01

    We perform a combined analysis of recent NEOS and Daya Bay data on the reactor antineutrino spectrum. This analysis includes approximately 1.5 million antineutrino events, which is the largest neutrino event sample analyzed to date. We use a double ratio which cancels flux model dependence and related uncertainties as well as the effects of the detector response model. We find at 3-4 standard deviation significance level, that plutonium-239 and plutonium-241 are disfavored as the single source for the the so-called 5 MeV bump. This analysis method has general applicability and in particular with higher statistics data sets will be able to shed significant light on the issue of the bump. With some caveat this also should allow to improve the sensitivity for sterile neutrino searches in NEOS.

  8. Design of 10 MeV cyclotron accelerator

    Directory of Open Access Journals (Sweden)

    R Solhju

    2015-09-01

    Full Text Available Design and construction of 10MeV cyclotron has been started at Amirkabir University of Technology since 2012. So far, the conceptual and detail engineering design phases have been finalized. The main purpose of this baby cyclotron is to generate proton beam for the production of PET radioisotopes. The cyclotron consists of magnet, cavity, ion source, RF and LLRF system, vacuum system, cooling system, power amplifiers and power supplies system. In this paper, a brief of design principles for all the parts of cyclotron and their final simulation results is presented. It should be noted that these simulations have been performed and optimized by the most accurate softwares such as TOSCA, ANSYS, HFSS, SolidWorks and CST. Also, the manufacturing feasibility of all the parts is performed and their dimensions and parameters are synchronized with manufacturing standards

  9. Focussed MeV ion beam implanted waveguides

    Energy Technology Data Exchange (ETDEWEB)

    Von Bibra, M.L.; Roberts, A.; Nugent, K.; Jamieson, D.N. [Melbourne Univ., Parkville, VIC (Australia). School of Physics

    1996-12-31

    Single mode buried optical waveguides have been fabricated in fused silica by MeV proton implantation using a focussed hydrogen ion beam. The technique has the potential to direct write waveguide devices and produce multi-layered structures, without the need for intermediate steps such as mask fabrication or layered depositions. A micron resolution Confocal Raman Spectrometer has been used to map the distribution of atomic vacancies that forms the waveguiding region. The results are compared with theoretical calculations. Losses of 3 dB cm{sup -1} have been measured in unannealed samples, which decreases to less than 0.5 dB cm{sup -1} after annealing at 500 degrees Celsius. We describe methods for determining the refractive index distribution of single mode buried waveguides from their output intensity distributions via an inversion of the scalar wave equation. (authors). 5 figs.

  10. Calculation of the Energy Dependence of Dosimeter Response to Ionizing Photons

    DEFF Research Database (Denmark)

    Miller, Arne; McLaughlin, W. L.

    1982-01-01

    Using a program in BASIC applied to a desk-top calculator, simplified calculations provide approximate energy dependence correction factors of dosimeter readings of absorbed dose according to Bragg-Gray cavity theories. Burlin's general cavity theory is applied in the present calculations, and ce...... as given here are available for certain dosimeter probe materials and combinations used with intermediate energy photon spectra (0.01–100 MeV)....

  11. Measurement of Direct Photon Emission in K{sup +}{yields}{pi}{sup +}{pi}

    Energy Technology Data Exchange (ETDEWEB)

    Adler, S.; Aoki, M.; Ardebili, M.; Atiya, M. S.; Bergbusch, P. C.; Blackmore, E. W.; Bryman, D. A.; Chiang, I.-H.; Convery, M. R.; Diwan, M. V. (and others)

    2000-12-04

    We have performed a measurement of the K{sup +}{yields}{pi}{sup +}{pi}{sup 0}{gamma} decay and have observed 2x10{sup 4} events. The best fit to the decay spectrum gives a branching ratio for direct photon emission of (4.7{+-}0.8{+-}0.3)x10{sup -6} in the {pi}{sup +} kinetic energy region of 55 to 90MeV and requires no component due to interference with inner bremsstrahlung.

  12. Shielding measurements for a 230 MeV proton beam

    Energy Technology Data Exchange (ETDEWEB)

    Siebers, J.V.

    1990-01-01

    Energetic secondary neutrons produced as protons interact with accelerator components and patients dominate the radiation shielding environment for proton radiotherapy facilities. Due to the scarcity of data describing neutron production, attenuation, absorbed dose, and dose equivalent values, these parameters were measured for 230 MeV proton bombardment of stopping length Al, Fe, and Pb targets at emission angles of 0{degree}, 22{degree}, 45{degree}, and 90{degree} in a thick concrete shield. Low pressure tissue-equivalent proportional counters with volumes ranging from 1 cm{sup 3} to 1000 cm{sup 3} were used to obtain microdosimetric spectra from which absorbed dose and radiation quality are deduced. Does equivalent values and attenuation lengths determined at depth in the shield were found to vary sharply with angle, but were found to be independent of target material. Neutron dose and radiation length values are compared with Monte Carlo neutron transport calculations performed using the Los Alamos High Energy Transport Code (LAHET). Calculations used 230 MeV protons incident upon an Fe target in a shielding geometry similar to that used in the experiment. LAHET calculations overestimated measured attenuation values at 0{degree}, 22{degree}, and 45{degree}, yet correctly predicted the attenuation length at 90{degree}. Comparison of the mean radiation quality estimated with the Monte Carlo calculations with measurements suggest that neutron quality factors should be increased by a factor of 1.4. These results are useful for the shielding design of new facilities as well as for testing neutron production and transport calculations.

  13. Effective atomic number and electron density of amino acids within the energy range of 0.122-1.330 MeV

    Science.gov (United States)

    More, Chaitali V.; Lokhande, Rajkumar M.; Pawar, Pravina P.

    2016-08-01

    Photon attenuation coefficient calculation methods have been widely used to accurately study the properties of amino acids such as n-acetyl-L-tryptophan, n-acetyl-L-tyrosine, D-tryptophan, n-acetyl-L-glutamic acid, D-phenylalanine, and D-threonine. In this study, mass attenuation coefficients (μm) of these amino acids for 0.122-, 0.356-, 0.511-, 0.662-, 0.884-, 1.170, 1.275-, 1.330-MeV photons are determined using the radio-nuclides Co57, Ba133, Cs137, Na22, Mn54, and Co60. NaI (Tl) scintillation detection system was used to detect gamma rays with a resolution of 8.2% at 0.662 MeV. The calculated attenuation coefficient values were then used to determine total atomic cross sections (σt), molar extinction coefficients (ε), electronic cross sections (σe), effective atomic numbers (Zeff), and effective electron densities (Neff) of the amino acids. Theoretical values were calculated based on the XCOM data. Theoretical and experimental values are found to be in a good agreement (error<5%). The variations of μm, σt, ε, σe, Zeff, and Neff with energy are shown graphically. The values of μm, σt, ε, σe are higher at lower energies, and they decrease sharply as energy increases; by contrast, Zeff and Neff were found to be almost constant.

  14. Charged-particle beam diagnostics for the advanced photon source

    Science.gov (United States)

    Lumpkin, A. H.; Decker, G.; Kahana, E.; Patterson, D.; Sellyey, W.; Wang, X.; Chung, Y.

    1993-07-01

    Plans, prototypes, and initial test results for the charged-particle beam (e -, e +) diagnostic systems on the injector rings, their transport lines, and the storage ring for the Advanced Photon Source (APS) are presented. The APS will be a synchrotron radiation user facility with one of the world's brightest X-ray sources in the 10-keV regime. Its 200-MeV electron linac, 450-MeV positron linac, positron accumulator ring, 7-GeV injector synchrotron (IS), 7-GeV storage ring (SR), and undulator test lines will also demand the development and demonstration of key particle-beam characterization techniques over a wide range of parameter space. Some of these parameter values overlap or approach those projected for fourth generation light sources (linac-driven FELs and high brightness storage rings) as described at a recent workshop. Initial results from the diagnostics prototypes on the linac test stand operating at 45-MeV include current monitor data, beam loss monitor data, and video digitization using VME architecture.

  15. New measurement on photon yields from air and the application to the energy estimation of primary cosmic rays

    CERN Document Server

    Nagano, M; Sakaki, N; Ando, K

    2004-01-01

    The air fluorescence technique is used to detect ultra-high energy cosmic rays (UHECR), and to estimate their energy. Of fundamental importance is the photon yield due to excitation by electrons, in air of various densities and temperatures. After our previous report, the experiment has been continued using a Sr90 $\\beta$ source to study the pressure dependence of photon yields for radiation in nitrogen and dry air. The photon yields in 15 wave bands between 300 nm and 430 nm have been determined. The total photon yield between 300 nm and 406 nm (used in most experiments) in air excited by a 0.85 MeV electron is 3.81+-0.13 (+-13 % systematics) photons per meter at 1013 hPa and 20 $^{\\circ}$C. The air density and temperature dependencies of 15 wave bands are given for application to UHECR observations.

  16. Dose response of commercially available optically stimulated luminescent detector, Al2O3:C for megavoltage photons and electrons.

    Science.gov (United States)

    Kim, Dong Wook; Chung, Weon Kuu; Shin, Dong Oh; Yoon, Myonggeun; Hwang, Ui-Jung; Rah, Jeong-Eun; Jeong, Hojin; Lee, Sang Yeob; Shin, Dongho; Lee, Se Byeong; Park, Sung Yong

    2012-04-01

    This study examined the dose response of an optically stimulated luminescence dosemeter (OSLD) to megavoltage photon and electron beams. A nanoDot™ dosemeter was used to measure the dose response of the OSLD. Photons of 6-15 MV and electrons of 9-20 MeV were delivered by a Varian 21iX machine (Varian Medical System, Inc. Milpitas, CA, USA). The energy dependency was photons, the dose was linear until 200 cGy. The superficial dose measurements revealed photon irradiation to have an angular dependency. The nanoDot™ dosemeter has potential use as an in vivo dosimetric tool that is independent of the energy, has dose linearity and a rapid response compared with normal in vivo dosimetric tools, such as thermoluminescence detectors. However, the OSLD must be treated very carefully due to the high angular dependency of the photon beam.

  17. Calculation of absorbed dose and biological effectiveness from photonuclear reactions in a bremsstrahlung beam of end point 50 MeV.

    Science.gov (United States)

    Gudowska, I; Brahme, A; Andreo, P; Gudowski, W; Kierkegaard, J

    1999-09-01

    The absorbed dose due to photonuclear reactions in soft tissue, lung, breast, adipose tissue and cortical bone has been evaluated for a scanned bremsstrahlung beam of end point 50 MeV from a racetrack accelerator. The Monte Carlo code MCNP4B was used to determine the photon source spectrum from the bremsstrahlung target and to simulate the transport of photons through the treatment head and the patient. Photonuclear particle production in tissue was calculated numerically using the energy distributions of photons derived from the Monte Carlo simulations. The transport of photoneutrons in the patient and the photoneutron absorbed dose to tissue were determined using MCNP4B; the absorbed dose due to charged photonuclear particles was calculated numerically assuming total energy absorption in tissue voxels of 1 cm3. The photonuclear absorbed dose to soft tissue, lung, breast and adipose tissue is about (0.11-0.12)+/-0.05% of the maximum photon dose at a depth of 5.5 cm. The absorbed dose to cortical bone is about 45% larger than that to soft tissue. If the contributions from all photoparticles (n, p, 3He and 4He particles and recoils of the residual nuclei) produced in the soft tissue and the accelerator, and from positron radiation and gammas due to induced radioactivity and excited states of the nuclei, are taken into account the total photonuclear absorbed dose delivered to soft tissue is about 0.15+/-0.08% of the maximum photon dose. It has been estimated that the RBE of the photon beam of 50 MV acceleration potential is approximately 2% higher than that of conventional 60Co radiation.

  18. CMOS-compatible photonic devices for single-photon generation

    Directory of Open Access Journals (Sweden)

    Xiong Chunle

    2016-09-01

    Full Text Available Sources of single photons are one of the key building blocks for quantum photonic technologies such as quantum secure communication and powerful quantum computing. To bring the proof-of-principle demonstration of these technologies from the laboratory to the real world, complementary metal–oxide–semiconductor (CMOS-compatible photonic chips are highly desirable for photon generation, manipulation, processing and even detection because of their compactness, scalability, robustness, and the potential for integration with electronics. In this paper, we review the development of photonic devices made from materials (e.g., silicon and processes that are compatible with CMOS fabrication facilities for the generation of single photons.

  19. Photonic band gap of 2D complex lattice photonic crystal

    Institute of Scientific and Technical Information of China (English)

    GUAN Chun-ying; YUAN Li-bo

    2009-01-01

    It is of great significance to present a photonic crystal lattice structure with a wide photonic bandgap. A two-dimension complex lattice photonic crystal is proposed. The photonic crystal is composed of complex lattices with triangular structure, and each single cell is surrounded by six scatterers in an hexagon. The photonic band gaps are calculated based on the plane wave expansion (PWE) method. The results indicate that the photonic crystal has tunable large TM polarization band gap, and a gap-midgap ratio of up to 45.6%.

  20. Improved photon counting efficiency calibration using superconducting single photon detectors

    Science.gov (United States)

    Gan, Haiyong; Xu, Nan; Li, Jianwei; Sun, Ruoduan; Feng, Guojin; Wang, Yanfei; Ma, Chong; Lin, Yandong; Zhang, Labao; Kang, Lin; Chen, Jian; Wu, Peiheng

    2015-10-01

    The quantum efficiency of photon counters can be measured with standard uncertainty below 1% level using correlated photon pairs generated through spontaneous parametric down-conversion process. Normally a laser in UV, blue or green wavelength range with sufficient photon energy is applied to produce energy and momentum conserved photon pairs in two channels with desired wavelengths for calibration. One channel is used as the heralding trigger, and the other is used for the calibration of the detector under test. A superconducting nanowire single photon detector with advantages such as high photon counting speed (optical spectroscopy, super resolution microscopy, deep space observation, and so on.

  1. Two-photon Interference with Non-identical Photons

    CERN Document Server

    Liu, Jianbin; Zheng, Huaibin; Chen, Hui; Li, Fu-Li; Xu, Zhuo

    2014-01-01

    The indistinguishability of non-identical photons is dependent on detection system in quantum physics. If two photons with different wavelengths are indistinguishable for a detection system, there can be two-photon interference when these two photons are incident to two input ports of a Hong-Ou-Mandel interferometer, respectively. The reason why two-photon interference phenomena are different for classical and nonclassical light is not due to interference, but due to the properties of light and detection system. These conclusions are helpful to understand the physics and applications of two-photon interference.

  2. CMOS-compatible photonic devices for single-photon generation

    Science.gov (United States)

    Xiong, Chunle; Bell, Bryn; Eggleton, Benjamin J.

    2016-09-01

    Sources of single photons are one of the key building blocks for quantum photonic technologies such as quantum secure communication and powerful quantum computing. To bring the proof-of-principle demonstration of these technologies from the laboratory to the real world, complementary metal-oxide-semiconductor (CMOS)-compatible photonic chips are highly desirable for photon generation, manipulation, processing and even detection because of their compactness, scalability, robustness, and the potential for integration with electronics. In this paper, we review the development of photonic devices made from materials (e.g., silicon) and processes that are compatible with CMOS fabrication facilities for the generation of single photons.

  3. Neutron-induced fission cross sections of uraniums up to 40 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Maslov, V.M. [Radiation Physics and Chemistry Problems Inst., Minsk-Sosny (Belarus); Hasegawa, A.

    1998-11-01

    Statistical theory of nuclear reactions, well-proved below 20 MeV, is applied for {sup 235}U and {sup 238}U fission data analysis up to {approx}40 MeV. It is shown that measured data could be reproduced. Chance structure of measured fission cross section is provided, it`s validity is supported by description of data for competing (n,xn)-reactions. Role of fissility of target nucleus is addressed. It seems that gap in incident neutron energy interval of 20 MeV - 50 MeV, below which evaluation approaches are well-developed, and above which simplified statistical approaches are valid, could be covered. (author)

  4. Backward Secondary Electron Emission Yield of Thick Targets Induced by MeV Ions

    Institute of Scientific and Technical Information of China (English)

    JIANG Lei; ZHAO Guo-Qing; ZHOU Zhu-Ying

    2000-01-01

    The backward secondary electron emission yields of MeV ions (H+, He+, He++, Cl, Si, and Cu ) impinging on thick carbon and gold targets are studied. The measured results for H+ (1MeV ≤ E ≤ 5MeV) on carbon are proportional to the electronic stopping power. Our experimental data and fitting formula of yields for H+ (1 MeV≤ E≤ 4.5MeV) impacting Au are compared with the theoretical expectation. The influence of the collective field and the charge state of ions on the secondary electron emission yield is discussed.

  5. One-photon pair annihilation in magnetized relativistic plasmas

    Science.gov (United States)

    Harding, A. K.

    1986-01-01

    In supersonic magnetic fields, electron-positron pairs may annihilate into single photons producing spectral features above 1 MeV. The paper calculates the exact one-photon annihilation rate in the general case where pairs may annihilate from excited Landau states, extending the previous studies which were restricted to pairs in the ground state. Asymptotic expressions for annihilation spectra and rates in the limit of large pair quantum numbers are also derived. It is found that the rate of annihilation from excited states can exceed the rate from the ground state by orders of magnitude in fields less than about 2 x 10 to the 12th G. This allows one-photon annihilation to be competitive with the two-photon process at typical neutron star field strengths. Annihilation spectra from a Maxwellian pair plasma at transrelativistic temperatures show fine structure near threshold on a scale (h/2pi)omega sub B as the result of contributions from individual pair states, which blend into a smooth continuum at higher energies.

  6. Improvement of Photon Buildup Factors for Radiological Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Schirmers, Fritz Gordon [North Carolina State Univ., Raleigh, NC (United States)

    2006-07-01

    Slant-path buildup factors for photons between 1 keV and 10 MeV for nine radiation shielding materials (air, aluminum, concrete, iron, lead, leaded glass, polyethylene, stainless steel, and water) are calculated with the most recent cross-section data available using Monte Carlo and discrete ordinates methods. Discrete ordinates calculations use a 244-group energy structure that is based on previous research at Los Alamos National Laboratory (LANL), but extended with the results of this thesis, and its focused studies on low-energy photon transport and the effects of group widths in multigroup calculations. Buildup factor calculations in discrete ordinates benefit from coupled photon/electron cross sections to account for secondary photon effects. Also, ambient dose equivalent (herein referred to as dose) buildup factors were analyzed at lower energies where corresponding response functions do not exist in literature. The results of these studies are directly applicable to radiation safety at LANL, where the dose modeling tool Pandemonium is used to estimate worker dose in plutonium handling facilities. Buildup factors determined in this thesis will be used to enhance the code's modeling capabilities, but should be of interest to the radiation shielding community.

  7. Universal Parametrization of Thermal Photon Rates in Hadronic Matter

    CERN Document Server

    Heffernan, Matthew; Rapp, Ralf

    2014-01-01

    Electromagnetic (EM) radiation off strongly interacting matter created in high-energy heavy-ion collisions (HICs) encodes information on the high-temperature phases of nuclear matter. Microscopic calculations of thermal EM emission rates are usually rather involved and not readily accessible to broad applications in models of the fireball evolution which are required to compare to experimental data. An accurate and universal parametrization of the microscopic calculations is thus key to honing the theory behind the EM spectra. Here we provide such a parametrization for photon emission rates from hadronic matter, including the contributions from in-medium rho mesons (which incorporate effects from anti-/baryons), as well as Bremsstrahlung from pi-pi scattering. Individual parametrizations for each contribution are numerically determined through nested fitting functions for photon energies from 0.2 to 5 GeV in chemically equilibrated matter of temperatures 100-180 MeV and baryon chemical potentials 0-400 MeV. S...

  8. Photon flux and spectrum of {gamma}-rays Compton sources

    Energy Technology Data Exchange (ETDEWEB)

    Petrillo, V., E-mail: Petrillo@mi.infn.it [INFN Milano, Via Celoria, 16 20133 Milano (Italy); Universita degli Studi di Milano, Via Celoria, 16 20133 Milano (Italy); Bacci, A. [INFN Milano, Via Celoria, 16 20133 Milano (Italy); Ben Ali Zinati, R. [Universita degli Studi di Milano, Via Celoria, 16 20133 Milano (Italy); Chaikovska, I. [LAL Universite Paris-Sud IN2P3/CNRS, Orsay-Ville (France); Curatolo, C. [INFN Milano, Via Celoria, 16 20133 Milano (Italy); Universita degli Studi di Milano, Via Celoria, 16 20133 Milano (Italy); Ferrario, M. [LNF, INFN Via E.Fermi, 40 Frascati, Roma (Italy); Maroli, C. [Universita degli Studi di Milano, Via Celoria, 16 20133 Milano (Italy); Ronsivalle, C. [ENEA Via E.Fermi, 45 Frascati, Roma (Italy); Rossi, A.R.; Serafini, L. [INFN Milano, Via Celoria, 16 20133 Milano (Italy); Tomassini, P. [Universita degli Studi di Milano, Via Celoria, 16 20133 Milano (Italy); Vaccarezza, C. [LNF, INFN Via E.Fermi, 40 Frascati, Roma (Italy); Variola, A. [LAL Universite Paris-Sud IN2P3/CNRS, Orsay-Ville (France)

    2012-11-21

    We analyze the characteristics of the {gamma} radiation produced by Compton back-scattering of a high brightness electron beam produced by a photoinjector and accelerated in a linac up to energies of 360-720 MeV and a laser operated at about 500 nm, by comparing classical and quantum models and codes. The interaction produces {gamma} rays in the range 4.9-18.8 MeV. In view of the application to nuclear resonance fluorescence a relative bandwidth of few 10{sup -3} is needed. The bandwidth is reduced by taking advantage of the frequency-angular correlation typical of the phenomenon and selecting the radiation in an angle of tens of {mu}rads. The foreseen spectral density is 20-6 photons per eV in a single shot, a number that can be increased by developing multi-bunch techniques and laser recirculation. In this way a final value of 10{sup 4} photon per eV per second can be achieved.

  9. Photon flux and spectrum of γ-rays Compton sources

    Science.gov (United States)

    Petrillo, V.; Bacci, A.; Ben Alì Zinati, R.; Chaikovska, I.; Curatolo, C.; Ferrario, M.; Maroli, C.; Ronsivalle, C.; Rossi, A. R.; Serafini, L.; Tomassini, P.; Vaccarezza, C.; Variola, A.

    2012-11-01

    We analyze the characteristics of the γ radiation produced by Compton back-scattering of a high brightness electron beam produced by a photoinjector and accelerated in a linac up to energies of 360-720 MeV and a laser operated at about 500 nm, by comparing classical and quantum models and codes. The interaction produces γ rays in the range 4.9-18.8 MeV. In view of the application to nuclear resonance fluorescence a relative bandwidth of few 10-3 is needed. The bandwidth is reduced by taking advantage of the frequency-angular correlation typical of the phenomenon and selecting the radiation in an angle of tens of μrads. The foreseen spectral density is 20-6 photons per eV in a single shot, a number that can be increased by developing multi-bunch techniques and laser recirculation. In this way a final value of 104 photon per eV per second can be achieved.

  10. Antigravity Acts on Photons

    Science.gov (United States)

    Brynjolfsson, Ari

    2002-04-01

    Einstein's general theory of relativity assumes that photons don't change frequency as they move from Sun to Earth. This assumption is correct in classical physics. All experiments proving the general relativity are in the domain of classical physics. This include the tests by Pound et al. of the gravitational redshift of 14.4 keV photons; the rocket experiments by Vessot et al.; the Galileo solar redshift experiments by Krisher et al.; the gravitational deflection of light experiments by Riveros and Vucetich; and delay of echoes of radar signals passing close to Sun as observed by Shapiro et al. Bohr's correspondence principle assures that quantum mechanical theory of general relativity agrees with Einstein's classical theory when frequency and gravitational field gradient approach zero, or when photons cannot interact with the gravitational field. When we treat photons as quantum mechanical particles; we find that gravitational force on photons is reversed (antigravity). This modified theory contradicts the equivalence principle, but is consistent with all experiments. Solar lines and distant stars are redshifted in accordance with author's plasma redshift theory. These changes result in a beautiful consistent cosmology.

  11. Nonlinear silicon photonics

    Science.gov (United States)

    Tsia, Kevin K.; Jalali, Bahram

    2010-05-01

    An intriguing optical property of silicon is that it exhibits a large third-order optical nonlinearity, with orders-ofmagnitude larger than that of silica glass in the telecommunication band. This allows efficient nonlinear optical interaction at relatively low power levels in a small footprint. Indeed, we have witnessed a stunning progress in harnessing the Raman and Kerr effects in silicon as the mechanisms for enabling chip-scale optical amplification, lasing, and wavelength conversion - functions that until recently were perceived to be beyond the reach of silicon. With all the continuous efforts developing novel techniques, nonlinear silicon photonics is expected to be able to reach even beyond the prior achievements. Instead of providing a comprehensive overview of this field, this manuscript highlights a number of new branches of nonlinear silicon photonics, which have not been fully recognized in the past. In particular, they are two-photon photovoltaic effect, mid-wave infrared (MWIR) silicon photonics, broadband Raman effects, inverse Raman scattering, and periodically-poled silicon (PePSi). These novel effects and techniques could create a new paradigm for silicon photonics and extend its utility beyond the traditionally anticipated applications.

  12. Photonics for life.

    Science.gov (United States)

    Cubeddu, Rinaldo; Bassi, Andrea; Comelli, Daniela; Cova, Sergio; Farina, Andrea; Ghioni, Massimo; Rech, Ivan; Pifferi, Antonio; Spinelli, Lorenzo; Taroni, Paola; Torricelli, Alessandro; Tosi, Alberto; Valentini, Gianluca; Zappa, Franco

    2011-01-01

    Light is strictly connected with life, and its presence is fundamental for any living environment. Thus, many biological mechanisms are related to light interaction or can be evaluated through processes involving energy exchange with photons. Optics has always been a precious tool to evaluate molecular and cellular mechanisms, but the discovery of lasers opened new pathways of interactions of light with biological matter, pushing an impressive development for both therapeutic and diagnostic applications in biomedicine. The use of light in different fields has become so widespread that the word photonics has been utilized to identify all the applications related to processes where the light is involved. The photonics area covers a wide range of wavelengths spanning from soft X-rays to mid-infrared and includes all devices related to photons as light sources, optical fibers and light guides, detectors, and all the related electronic equipment. The recent use of photons in the field of telecommunications has pushed the technology toward low-cost, compact, and efficient devices, making them available for many other applications, including those related to biology and medicine where these requirements are of particular relevance. Moreover, basic sciences such as physics, chemistry, mathematics, and electronics have recognized the interdisciplinary need of biomedical science and are translating the most advanced researches into these fields. The Politecnico school has pioneered many of them,and this article reviews the state of the art of biomedical research at the Politecnico in the field internationally known as biophotonics.

  13. Axion mediated photon to dark photon mixing

    CERN Document Server

    Ejlli, Damian

    2016-01-01

    The interaction between dark/mirror sector and ordinary sector is considered, where the two sectors interact with each other by sharing the same QCD axion field. This feature makes possible the mixing between ordinary and dark/mirror photons in ordinary and dark electromagnetic fields. Exact and perturbative solutions of equation of motions describing the evolution of fields in ordinary and dark external magnetic fields are found. User friendly quantities such as transition probability rates, induced phase shifts and angle of rotation of the polarization plane of light are derived. Possible astrophysical and cosmological applications of this mechanism are suggested.

  14. A comparative study of 30MeV boron{sup 4+} and 60MeV oxygen{sup 8+} ion irradiated Si NPN BJTs

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, M. Vinay, E-mail: Vkm288@gmail.com; Krishnaveni, S. [Department of studies in Physics, University of Mysore, Manasagangotri, Mysore 570006 (India); Yashoda, T. [Deparment of Physics, AVK College for women, Hassan-573201 (India); Dinesh, C. M. [Department of Physics, Govt. First grade college for women, Chintamani-563125 (India); Krishnakumar, K. S. [Department of Physics, APS College of Engineering (India); Jayashree, B. [Department of Physics, Maharanis Science College for Women, Bangalore-560001 (India); Ramani [Department of Physics, Bangalore University, Jnanabharathi, Bangalore-560056 (India)

    2015-06-24

    The impact of 30MeV boron{sup 4+} and 60MeV oxygen{sup 8+} ion irradiation on electrical characteristics of 2N3773 Si NPN Bipolar junction transistors (BJTs) is reported in the present study. The transistors were decapped and irradiated at room temperature. Gummel characteristics, DC current gain and Capacitance-voltage (C-V) characteristics were studied before and after irradiation at different fluences. DC current gain has decreased significantly in both boron and oxygen ion irradiation. Also the value of capacitance decreased 3-4 times with increase in fluence. Both 30MeV boron ion and 60MeV oxygen ion induced similar extent of degradation in electrical characteristics of the transistor.

  15. A comparative study of 30MeV boron4+ and 60MeV oxygen8+ ion irradiated Si NPN BJTs

    Science.gov (United States)

    Kumar, M. Vinay; Yashoda, T.; Dinesh, C. M.; Krishnakumar, K. S.; Jayashree, B.; Ramani, Krishnaveni, S.

    2015-06-01

    The impact of 30MeV boron4+ and 60MeV oxygen8+ ion irradiation on electrical characteristics of 2N3773 Si NPN Bipolar junction transistors (BJTs) is reported in the present study. The transistors were decapped and irradiated at room temperature. Gummel characteristics, DC current gain and Capacitance-voltage (C-V) characteristics were studied before and after irradiation at different fluences. DC current gain has decreased significantly in both boron and oxygen ion irradiation. Also the value of capacitance decreased 3-4 times with increase in fluence. Both 30MeV boron ion and 60MeV oxygen ion induced similar extent of degradation in electrical characteristics of the transistor.

  16. Energy spectrum measurement of high power and high energy(6 and 9 MeV) pulsed x-ray source for industrial use

    Energy Technology Data Exchange (ETDEWEB)

    Takagi, Hiroyuki [Hitachi, Ltd. Power Systems Company, Ibaraki (Japan); Murata, Isao [Graduate School of Engineering, Osaka University, Osaka (Japan)

    2016-06-15

    Industrial X-ray CT system is normally applied to non-destructive testing (NDT) for industrial product made from metal. Furthermore there are some special CT systems, which have an ability to inspect nuclear fuel assemblies or rocket motors, using high power and high energy (more than 6 MeV) pulsed X-ray source. In these case, pulsed X-ray are produced by the electron linear accelerator, and a huge number of photons with a wide energy spectrum are produced within a very short period. Consequently, it is difficult to measure the X-ray energy spectrum for such accelerator-based X-ray sources using simple spectrometry. Due to this difficulty, unexpected images and artifacts which lead to incorrect density information and dimensions of specimens cannot be avoided in CT images. For getting highly precise CT images, it is important to know the precise energy spectrum of emitted X-rays. In order to realize it we investigated a new approach utilizing the Bayesian estimation method combined with an attenuation curve measurement using step shaped attenuation material. This method was validated by precise measurement of energy spectrum from a 1 MeV electron accelerator. In this study, to extend the applicable X-ray energy range we tried to measure energy spectra of X-ray sources from 6 and 9 MeV linear accelerators by using the recently developed method. In this study, an attenuation curves are measured by using a step-shaped attenuation materials of aluminum and steel individually, and the each X-ray spectrum is reconstructed from the measured attenuation curve by the spectrum type Bayesian estimation method. The obtained result shows good agreement with simulated spectra, and the presently developed technique is adaptable for high energy X-ray source more than 6 MeV.

  17. Observational capabilities of solar satellite "Coronas-Photon"

    Science.gov (United States)

    Kotov, Yu.

    Coronas-Photon mission is the third satellite of the Russian Coronas program on solar activity observation The main goal of the Coronas-Photon is the study of solar hard electromagnetic radiation in the wide energy range from UV up to high energy gamma-radiation sim 2000MeV Scientific payload for solar radiation observation consists of three type of instruments 1 monitors Natalya-2M Konus-RF RT-2 Penguin-M BRM Phoka Sphin-X Sokol for spectral and timing measurements of full solar disk radiation with timing in flare burst mode up to one msec Instruments Natalya-2M Konus-RF RT-2 will cover the wide energy range of hard X-rays and soft Gamma rays 15keV to 2000MeV and will together constitute the largest area detectors ever used for solar observations Detectors of gamma-ray monitors are based on structured inorganic scintillators with energy resolution sim 5 for nuclear gamma-line band to 35 for GeV-band PSD analysis is used for gamma neutron separation for solar neutron registration T 30MeV Penguin-M has capability to measure linear polarization of hard X-rays using azimuth are measured by Compton scattering asymmetry in case of polarization of an incident flux For X-ray and EUV monitors the scintillation phoswich detectors gas proportional counter CZT assembly and Filter-covered Si-diodes are used 2 Telescope-spectrometer TESIS for imaging solar spectroscopy in X-rays with angular resolution up to 1 in three spectral lines and RT-2 CZT assembly of CZT

  18. Anti-photon

    CERN Document Server

    Moret-Bailly, Jacques

    2010-01-01

    The purpose of this article is neither a compilation, nor a critique of the article by W. E. Lamb of which it gets the name: It adds arguments and applications. Quantum electrodynamics quantizes "normal modes" chosen arbitrarily among the infinity of sets of orthogonal modes of the electromagnetic field. Changing the choice of normal modes splits the photons which are not physical objects. The classical field of electromagnetic energy is often, wrongly, considered as linear, so that Bohr's electron falls on the nucleus and photon counting is false. Using absolute energies and radiances avoids doing these errors. Considering the photons as small particles interacting without pilot waves with single atoms, astrophysicists use Monte-Carlo computations for the propagation of light in homogeneous media while it works only in opalescent media as clouds. Thus, for instance, two theories abort while, they are validated using coherence and Einstein theories, giving a good interpretation of the rings of supernova remna...

  19. Direct photons at FAIR

    Energy Technology Data Exchange (ETDEWEB)

    Baeuchle, Bjoern [Frankfurt Institute for Advanced Studies (FIAS), Ruth-Moufang-Str. 1, D-60438 Frankfurt am Main (Germany); Bleicher, Marcus; Grimm, Andreas [Frankfurt Institute for Advanced Studies (FIAS), Ruth-Moufang-Str. 1, D-60438 Frankfurt am Main (Germany); Frankfurt Univ. (Germany). Inst. fuer Theoretische Physik

    2013-07-01

    Photons, as all electromagnetic probes, can give direct access to the hot and dense phase of a heavy-ion reaction. We show calculations of direct photon emission at SiS100- and SiS-300 energies with the UrQMD-hybrid model. UrQMD is a full microscopic+macroscopic transport/fluid-dynamics hybrid model with hadron- and string-driven equilibration phase, a full (3+1)-dimensional fluiddynamic hot and dense phase and a hadronic after-burner. Unequilibrated matter at high rapidity is preserved during the fluid phase. A strong emphasis is set on the impact of viscosity and Equation of State at zero and non-zero baryon density to the spectra and flow patterns of thermal and non-thermal photons in A+A-collisions at the colliding systems relevant for FAIR.

  20. Photon kinetics in plasmas

    Directory of Open Access Journals (Sweden)

    V.G. Morozov

    2009-01-01

    Full Text Available We present a kinetic theory of radiative processes in many-component plasmas with relativistic electrons and nonrelativistic heavy particles. Using the non-equilibrium Green's function technique in many-particle QED, we show that the transverse field correlation functions can be naturally decomposed into sharply peaked (non-Lorentzian parts that describe resonant (propagating photons and off-shell parts corresponding to virtual photons in the medium. Analogous decompositions are obtained for the longitudinal field correlation functions and the correlation functions of relativistic electrons. We derive a kinetic equation for the resonant photons with a finite spectral width and show that the off-shell parts of the particle and field correlation functions are essential to calculate the local radiating power in plasmas and recover the results of vacuum QED. The plasma effects on radiative processes are discussed.

  1. Photonics: practically there?

    Directory of Open Access Journals (Sweden)

    Paula Gould

    2002-09-01

    Strange things happen to light when it passes through photonic crystals. A significant variation in refractive index between the material’s periodic lattice structure and its substrate traps transmitted photons in either one area or the other, creating distinct ‘allowed’ and ‘forbidden’ energy regions. Light with wavelengths equivalent to the forbidden region, the so-called photonic bandgap, is stopped from passing further. Wavelengths from the rest of the electromagnetic spectrum, on the other hand, are free to continue their passage through the material unhindered. In effect, the material is able to halt the passage of light just as the periodic potential of semiconductors, such as silicon, bars electrons from occupying the forbidden energy bandgap.

  2. Photonic Crystal Microchip Laser

    Science.gov (United States)

    Gailevicius, Darius; Koliadenko, Volodymyr; Purlys, Vytautas; Peckus, Martynas; Taranenko, Victor; Staliunas, Kestutis

    2016-09-01

    The microchip lasers, being very compact and efficient sources of coherent light, suffer from one serious drawback: low spatial quality of the beam strongly reducing the brightness of emitted radiation. Attempts to improve the beam quality, such as pump-beam guiding, external feedback, either strongly reduce the emission power, or drastically increase the size and complexity of the lasers. Here it is proposed that specially designed photonic crystal in the cavity of a microchip laser, can significantly improve the beam quality. Experiments show that a microchip laser, due to spatial filtering functionality of intracavity photonic crystal, improves the beam quality factor M2 reducing it by a factor of 2, and increase the brightness of radiation by a factor of 3. This comprises a new kind of laser, the “photonic crystal microchip laser”, a very compact and efficient light source emitting high spatial quality high brightness radiation.

  3. Mesoscopic photon heat transistor

    DEFF Research Database (Denmark)

    Ojanen, T.; Jauho, Antti-Pekka

    2008-01-01

    We show that the heat transport between two bodies, mediated by electromagnetic fluctuations, can be controlled with an intermediate quantum circuit-leading to the device concept of a mesoscopic photon heat transistor (MPHT). Our theoretical analysis is based on a novel Meir-Wingreen-Landauer-typ......We show that the heat transport between two bodies, mediated by electromagnetic fluctuations, can be controlled with an intermediate quantum circuit-leading to the device concept of a mesoscopic photon heat transistor (MPHT). Our theoretical analysis is based on a novel Meir......-Wingreen-Landauer-type of conductance formula, which gives the photonic heat current through an arbitrary circuit element coupled to two dissipative reservoirs at finite temperatures. As an illustration we present an exact solution for the case when the intermediate circuit can be described as an electromagnetic resonator. We discuss...

  4. Photon physics with PHENIX

    Energy Technology Data Exchange (ETDEWEB)

    White, S. [Brookhaven National Lab., Upton, NY (United States)

    1995-07-15

    In this Paper the author discusses briefly the physics motivation for extending measurements of particle production with high granularity and particle id capabilities to neutrals in PHENIX. The author then discusses the technique of direct photon measurement in the presence of copious background photons from {pi}{sup o} decays. The experiment will measure relatively low p{sub t} photons near y=0 in the lab frame. This new experimental environment of high multiplicity and low {gamma} momenta will affect both the techniques used and the type of analysis which can be performed. The Phenix Electromagnetic calorimeter is described and its capabilities illustrated with results from simulation and beam tests of the first production array.

  5. M-C simulation of shielding effects of PE, LiH and graphite fibers under 1 MeV electrons and 20 MeV protons

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Shielding effects of different materials under 1 MeV electron and 20 MeV proton beams were simulated with Geant4 code. It was found that shielding effects of polyethylene and graphite fibers are much better than aluminum. Energy depositions in the phantom shielded by the materials are calculated, with the least energy deposition by graphite fiber shielding. The results show that graphite fibers are good radiation shielding material in space programs.

  6. Modelling of neutron and photon transport in iron and concrete radiation shieldings by the Monte Carlo method - Version 2

    CERN Document Server

    Žukauskaite, A; Plukiene, R; Plukis, A

    2007-01-01

    Particle accelerators and other high energy facilities produce penetrating ionizing radiation (neutrons and γ-rays) that must be shielded. The objective of this work was to model photon and neutron transport in various materials, usually used as shielding, such as concrete, iron or graphite. Monte Carlo method allows obtaining answers by simulating individual particles and recording some aspects of their average behavior. In this work several nuclear experiments were modeled: AVF 65 – γ-ray beams (1-10 MeV), HIMAC and ISIS-800 – high energy neutrons (20-800 MeV) transport in iron and concrete. The results were then compared with experimental data.

  7. Interfacing single photons and single quantum dots with photonic nanostructures

    CERN Document Server

    Lodahl, Peter; Stobbe, Søren

    2013-01-01

    Photonic nanostructures provide a way of tailoring the interaction between light and matter and the past decade has witnessed a tremendous experimental and theoretical progress on this subject. In particular, the combination with semiconductor quantum dots has proven very successful. This manuscript reviews quantum optics with excitons in single quantum dots embedded in photonic nanostructures. The ability to engineer the interaction strength in integrated photonic nanostructures enables a range of fundamental quantum-electrodynamics experiments on, e.g., spontaneous-emission control, modified Lamb shifts, and enhanced dipole-dipole interaction. Furthermore, highly efficient single-photon sources and giant photon nonlinearities may be constructed with immediate applications for photonic quantum-information processing. The review summarizes the general theoretical framework of photon emission including the role of dephasing processes, and applies it to photonic nanostructures of current interest, such as photo...

  8. Photonic crystals as metamaterials

    Science.gov (United States)

    Foteinopoulou, S.

    2012-10-01

    The visionary work of Veselago had inspired intensive research efforts over the last decade, towards the realization of man-made structures with unprecedented electromagnetic (EM) properties. These structures, known as metamaterials, are typically periodic metallic-based resonant structures demonstrating effective constitutive parameters beyond the possibilities of natural material. For example they can exhibit optical magnetism or simultaneously negative effective permeability and permittivity which implies the existence of a negative refractive index. However, also periodic dielectric and polar material, known as photonic crystals, can exhibit EM capabilities beyond natural materials. This paper reviews the conditions and manifestations of metamaterial capabilities of photonic crystal systems.

  9. Coherent terahertz photonics.

    Science.gov (United States)

    Seeds, Alwyn J; Fice, Martyn J; Balakier, Katarzyna; Natrella, Michele; Mitrofanov, Oleg; Lamponi, Marco; Chtioui, Mourad; van Dijk, Frederic; Pepper, Michael; Aeppli, Gabriel; Davies, A Giles; Dean, Paul; Linfield, Edmund; Renaud, Cyril C

    2013-09-23

    We present a review of recent developments in THz coherent systems based on photonic local oscillators. We show that such techniques can enable the creation of highly coherent, thus highly sensitive, systems for frequencies ranging from 100 GHz to 5 THz, within an energy efficient integrated platform. We suggest that such systems could enable the THz spectrum to realize its full applications potential. To demonstrate how photonics-enabled THz systems can be realized, we review the performance of key components, show recent demonstrations of integrated platforms, and give examples of applications.

  10. Development and construction of the low-energy photon tagger NEPTUN

    Energy Technology Data Exchange (ETDEWEB)

    Lindenberg, K.

    2007-07-15

    Within the scope of this thesis a photon tagging system was designed and constructed at the superconducting Darmstadt electron linear accelerator (S-DALINAC). The set-up consists of a deflecting magnet, an array of focal plane detectors, the data acquisition system and new beam-line components. The system provides tagged photons in an energy range from 6 MeV to 20 MeV with the emphasis on best possible resolution and intensity. The absolute energy resolution of photons at 10 MeV is better than 25 keV. With the current focal-plane detectors a maximum rate of tagged photons of 10{sup 4}/(keV.s) can be achieved. An upgrade to more than 10{sup 5}/(keV.s) with an alternative detector array is under investigation. The design values mentioned above are the requirements for planned experiments in the fields of nuclear astrophysics and nuclear structure. The most important constraints which have to be considered arise from the special demands of ({gamma},n) reactions above but close to the particle threshold which generates slow neutrons with energies of a few hundreds of keV. The unambiguous assignment of slow neutrons to prompt electrons is done on-line in special buffered time-to-digital converters. With a design of the data acquisition for this scenario one also covers the requirements for experiments with prompt detection of the ejectiles such as in nuclear resonance fluorescence and ({gamma},n) far above the threshold. This photon tagging system enables to measure ({gamma},x) cross sections as a function of excitation energy and decay patterns after particle evaporation. It is an important extension to the high-flux activation experiments and the nuclear resonance fluorescence experiments below the threshold with untagged bremsstrahlung. (orig.)

  11. Two-photon interference of temporally separated photons

    Science.gov (United States)

    Kim, Heonoh; Lee, Sang Min; Moon, Han Seb

    2016-10-01

    We present experimental demonstrations of two-photon interference involving temporally separated photons within two types of interferometers: a Mach-Zehnder interferometer and a polarization-based Michelson interferometer. The two-photon states are probabilistically prepared in a symmetrically superposed state within the two interferometer arms by introducing a large time delay between two input photons; this state is composed of two temporally separated photons, which are in two different or the same spatial modes. We then observe two-photon interference fringes involving both the Hong-Ou-Mandel interference effect and the interference of path-entangled two-photon states simultaneously in a single interferometric setup. The observed two-photon interference fringes provide simultaneous observation of the interferometric properties of the single-photon and two-photon wavepackets. The observations can also facilitate a more comprehensive understanding of the origins of the interference phenomena arising from spatially bunched/anti-bunched two-photon states comprised of two temporally separated photons within the interferometer arms.

  12. High brightness single photon sources based on photonic wires

    DEFF Research Database (Denmark)

    Claudon, J.; Bleuse, J.; Bazin, M.;

    2009-01-01

    We present a novel single-photon-source based on the emission of a semiconductor quantum dot embedded in a single-mode photonic wire. This geometry ensures a very large coupling (> 95%) of the spontaneous emission to the guided mode. Numerical simulations show that a photon collection efficiency...

  13. Design of Cavity for 10 MeV Electron Irradiation Accelerator

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    This article describes the 10 MeV high-power electron irradiation accelerator. This accelerator can output varied energy electron beam which the highest energy is 10 MeV or shooting target produce X-rays for industrial radiation processing.

  14. Buncher Power Source Monitoring System of 100 MeV Cyclotron

    Institute of Scientific and Technical Information of China (English)

    WEI; Jun-yi; FU; Xiao-liang; GUO; Juan-juan; ZHANG; Yi-wang; CAO; Xue-long; YIN; Zhi-guo; JI; Bin

    2015-01-01

    The 100MeV cyclotron provides 70-100MeV and 200μA proton beam,which can be used in astrophysics,medical,defense,energy and other fields.Buncher system can enhance the beam intensity and expand the scope of application of the accelerator.Buncher system is one part of the

  15. Performance Results of the Modulator for the 100MeV Proton Linac

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dae Il; Kwon, Hyeok Jung; Kim, Han Sung; Seol, Kyung Tae; Cho, Yong Sub [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    The modulator for the 100MeV proton linac has been installed at KOMAC (Korea of Multi-purpose Accelerator Complex) site. The specification of modulator is 5.8MW peak power with 1.5ms pulse width, 60Hz repetition rate. There are total 4 sets of modulator for 100-MeV proton linac including 3-MeV RFQ, 20-MeV DTL and 100-MeV DTL. A modulator drives two or three sets of the klystrons simultaneously. After installation and du mmy test of 4 modulators, it has been operated for 100MeV proton linac. In this paper, the performance results of modulators for the 100MeV proton linac are presented. 4 modulators were installed and tested for the 100MeV proton linac. The modulator was measured to have about less than 1% droops at flat top for 500 us pulse by using pulse frequency modulation droop compensation method. The long term voltage variation measurement showed that the voltage increased up to 0.05% for 8 hours. In future, the voltage droop and variation of modulator should be continuously checked in the high repetition rate.

  16. Klystron High Power Operation for KOMAC 100-MeV Proton Linac

    Energy Technology Data Exchange (ETDEWEB)

    Seol, Kyung-Tae; Kim, Seong-Gu; Kwon, Hyeok-Jung; Kim, Han-Sung; Cho, Yong-Sub [KAERI, Daejeon (Korea, Republic of)

    2015-05-15

    The Korea multi-purpose accelerator complex (KOMAC) accelerator facility has a 100-MeV proton linac, five beam lines for 20-MeV beam utilization, and another five beam lines for 100-MeV beam utilization. The 100-MeV linac consists of a 50-keV proton injector based on a microwave ion source, a 3-MeV RFQ with a four-vane structure, and a 100-MeV DTL. Nine sets of 1MW klystrons have been operated for the 100-MeV proton linac. The klystron filament heating time was approximately 5700 hours in 2014, and RF operation time was 2863.4 hours. During the high power operation of the klystron, unstable RF waveforms appeared at the klystron output, and we have checked and performed cavity frequency adjustments, magnet and heater current, reflection from a circulator, klystron test without a circulator, and the frequency spectrum measurement. Nine sets of the klystrons have been operated for the KOMAC 100-MeV proton linac. The klystron filament heating time was 5700 hours and RF operation time was 2863.4 hours during the operation in 2014. Some klystrons have unstable RF waveforms at specific power level. We have checked and tested the cavity frequency adjustment, reflection from a circulator, high power test without a circulator, and frequency spectrum at the unstable RF.

  17. Initial Operation Results of the KOMAC 100MeV Proton Linac

    Energy Technology Data Exchange (ETDEWEB)

    Seol, Kyungtae; Kwon, Hyeokjung; Kim, Hansung; Kim, Daeil; Song, Younggi; Cho, Yongsub [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    The Korea multi-purpose accelerator complex (KOMAC) accelerator facility has a 100-MeV proton linac, five beam lines for 20-MeV beam utilization, and another five beam lines for 100-MeV beam utilization. The 100-MeV linac consists of a 50-keV proton injector based on a microwave ion source, a 3-MeV RFQ with a four-vane structure, and a 100-MeV DTL. The KOMAC started to provide a proton beam to users on July 2013. A 20-MeV beam line and a 100-MeV beam line have been operated for beam service during the first year. In 2013, the proton linac had been operated for more than 2200 hours and beam service time was 432 hours approximately. The accumulated downtime during the first year in 2013 is 94.7 hours and there were some faults at utilities, high voltage modulators, and RF components. The KOMAC started to provide a proton beam to users on July 2013. The proton linac had been operated for more than 2200 hours and beam service time was 432 hours approximately. Accumulated downtime was 94.7 hours and availability was 82 %. The plan for beam power and operation time in 2014 is 10 kW and 2500 hours respectively.

  18. Collective motion in selected central collisions of Au on Au at 150A MeV

    Science.gov (United States)

    Jeong, S. C.; Herrmann, N.; Fan, Z. G.; Freifelder, R.; Gobbi, A.; Hildenbrand, K. D.; Krämer, M.; Randrup, J.; Reisdorf, W.; Schüll, D.; Sodan, U.; Teh, K.; Wessels, J. P.; Pelte, D.; Trzaska, M.; Wienold, T.; Alard, J. P.; Amouroux, V.; Basrak, Z.; Bastid, N.; Belayev, I. M.; Berger, L.; Bini, M.; Blaich, Th.; Boussange, S.; Buta, A.; Čaplar, R.; Cerruti, C.; Cindro, N.; Coffin, J. P.; Dona, R.; Dupieux, P.; Erö, J.; Fintz, P.; Fodor, Z.; Fraysse, L.; Frolov, S.; Grigorian, Y.; Guillaume, G.; Hölbling, S.; Houari, A.; Jundt, F.; Kecskemeti, J.; Koncz, P.; Korchagin, Y.; Kotte, R.; Kuhn, C.; Ibnouzahir, M.; Legrand, I.; Lebedev, A.; Maguire, C.; Manko, V.; Maurenzig, P.; Mgebrishvili, G.; Mösner, J.; Moisa, D.; Montarou, G.; Montbel, I.; Morel, P.; Neubert, W.; Olmi, A.; Pasquali, G.; Petrovici, M.; Poggi, G.; Rami, F.; Ramillien, V.; Sadchikov, A.; Seres, Z.; Sikora, B.; Simion, V.; Smolyankin, S.; Tezkratt, R.; Vasiliev, M. A.; Wagner, P.; Wilhelmi, Z.; Wohlfarth, D.; Zhilin, A. V.

    1994-05-01

    Using the FOPI facility at GSI Darmstadt complete data of Au on Au collisions at 150A MeV were collected for charged products (Z=1-15) at laboratory angles 1°=3) are used to determine the collective energy which is found to be at least 10A MeV.

  19. Analysis of a measured neutron background below 6 MeV for fast-neutron imaging systems

    Science.gov (United States)

    Ide, K.; Becchetti, M. F.; Flaska, M.; Poitrasson-Riviere, A.; Hamel, M. C.; Polack, J. K.; Lawrence, C. C.; Clarke, S. D.; Pozzi, S. A.

    2012-12-01

    Detailed and accurate information on the neutron background is relevant for many applications that involve radiation detection, both for non-coincidence and coincidence countings. In particular, for the purpose of developing advanced neutron-detection techniques for nuclear non-proliferation and nuclear safeguards, the energy-dependent, ground-level, neutron-background information is needed. There are only a few previous studies available about the neutron background below 10 MeV, which is a typical neutron energy range of interest for nuclear non-proliferation and nuclear-safeguards applications. Thus, there is a potential for further investigation in this energy range. In this paper, neutron-background measurement results using organic-liquid scintillation detectors are described and discussed, with a direct application in optimization simulations of a fast-neutron imager based on liquid scintillators. The measurement was performed in summer 2011 in Ann Arbor, Michigan, USA, and the measurement setup consisted of several EJ-309 liquid scintillators and a fast waveform digitizer. The average neutron flux below 6 MeV was measured to be approximately 4e-4 counts/cm2/s. In addition, the relationship between the neutron-background count rate and various environmental quantities, such as humidity, at Earth's ground level was investigated and the results did not reveal any straightforward dependences. The measured pulse height distribution (PHD) was unfolded to determine the energy spectrum of the background neutrons. The unfolded neutron-background spectrum was implemented to a previously-created MCNPX-PoliMi model of the neutron-scatter camera and simple-backprojection images of the background neutrons were acquired. Furthermore, a simulated PHD was obtained with the MCNPX-PoliMi code using the "Cosmic-Ray Shower Library" (CRY) source sub-routine which returns various types of radiation, including neutrons and photons at a surface, and accounts for solar cycle

  20. CESAR, 2 MeV electron storage ring; general view.

    CERN Multimedia

    1964-01-01

    CESAR (CERN Electron Storage and Accumulation Ring) was built as a study-model for the ISR (Intersecting Storage Rings). The model had to be small (24 m circumference) and yet the particles had to be highly relativistic, which led to the choice of electrons. On the other hand, in order to model the behaviour of protons, effects from synchrotron radiation had to be negligible, which meant low magnetic fields (130 G in the bending magnets) and a corresponding low energy of 1.75 MeV. All the stacking (accumulation) procedures envisaged for the ISR were proven with CESAR, and critical aspects of transverse stability were explored. Very importantly, CESAR was the test-bed for the ultrahigh vacuum techniques and components, essential for the ISR, with a final pressure of 6E-11 Torr. The CESAR project was decided early in 1960, design was completed in 1961 and construction in 1963. After an experimental period from 1964 to 1967, CESAR was dismantled in 1968.

  1. CESAR, 2 MeV electron storage ring.

    CERN Multimedia

    1967-01-01

    CESAR (CERN Electron Storage and Accumulation Ring) was built as a study-model for the ISR (Intersecting Storage Rings). The model had to be small (24 m circumference) and yet the particles had to be highly relativistic, which led to the choice of electrons. On the other hand, in order to model the behaviour of protons, effects from synchrotron radiation had to be negligible, which meant low magnetic fields (130 G in the bending magnets) and a corresponding low energy of 1.75 MeV. All the stacking (accumulation) procedures envisaged for the ISR were proven with CESAR, and critical aspects of transverse stability were explored. Very importantly, CESAR was the test-bed for the ultrahigh vacuum techniques and components, essential for the ISR, with a final pressure of 6E-11 Torr. The CESAR project was decided early in 1960, design was completed in 1961 and construction in 1963. After an experimental period from 1964 to 1967, CESAR was dismantled in 1968.

  2. Multipurpose 5-MeV linear induction accelerator

    Science.gov (United States)

    Birx, D. L.; Hawkins, S. A.; Poor, S. E.; Reginato, L. L.; Smith, M. W.

    1984-06-01

    Although linear induction accelerators (LIAs) are quite reliable by most standards, they are limited in repeating rate, average power, and reliability because the final stage of energy delivery is based on spark gap performance. In addition, they have a low duty factor of operation. To provide a higher burst rate and greater reliability, new technology was used to develop a magnetic pulse compression scheme that eliminates all spark gaps and exceeds requirements. The magnetic drive system are tailored to drive induction cells from a few kA to over 10 kA at 500 kV, with average beam power levels in the megawatts. This new 5-MeV, 2.5-kA LIA under construction at the Lawrence Livermore National Laboratory (LLNL) will be used for the development of high brightness sources and will provide a test bed for the new technology, which should lead to LIAs that surpass the radio frequency linacs for efficiency and reliability, as well as fit other industrial applications, such as sewage sterilization.

  3. Multipurpose 5-MeV linear induction accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Birx, D.L.; Hawkins, S.A.; Poor, S.E.; Reginato, L.L. Smith, M.W.

    1984-06-11

    Although linear induction accelerators (LIAs) are quite reliable by most standards, they are limited in repeating rate, average power, and reliability because the final stage of energy delivery is based on spark gap performance. In addition, they have a low duty factor of operation. To provide a higher burst rate and greater reliability, the researchers used new technology to develop a magnetic pulse compression scheme that eliminates all spark gaps and exceeds requirements. The paper describes the scheme. The magnetic drive system can be tailored to drive induction cells from a few kA to over 10 kA at 500 kV, with average beam power levels in the megawatts. This new 5-MeV, 2.5-kA LIA under construction at the Lawrence Livermore National Laboratory (LLNL) will be used for the development of high brightness sources and will provide a test bed for the new technology, which should lead to LIAs that surpass the radio frequency linacs for efficiency and reliability, as well as fit other industrial applications, such as sewage sterilization.

  4. Two-photon cryomicroscope

    Science.gov (United States)

    Breunig, H. G.; Köhler, C.; König, K.

    2012-03-01

    We report on a new two-photon cryomicroscope which consist of a compact laser-scanning microscope combined with a motorized heating and freezing stage. Samples can be cooled down to -196 °C (77 K) and heated up to 600 °C (873 K) with adjustable heating/freezing rates between 0.01 K / min and 150 K / min. Two-photon imaging is realized by near infrared femtosecond-laser pulse excitation. The abilities of the two-photon cryomicroscope are illustrated in several measurements: imaging of fluorescent microspheres inside a piece of ice illustrates the feasibility of deep-microscopic imaging inside frozen sample. The temperature-dependent structural integrity of collagen is monitored by detection of second harmonic generation signals from porcine cornea. The measurements reveal also the dependence of the collagendenaturation temperature on hydration state of the cornea collagen. Furthermore, the potential of the two-photon cryomicroscope for optimization of freezing and thawing procedures as well as to evaluate the viability of frozen cells and tissue is discussed.

  5. Photon thermal Hall effect

    CERN Document Server

    Ben-Abdallah, Philippe

    2015-01-01

    A near-field thermal Hall effect (i.e.Righi-Leduc effect) in lattices of magneto-optical particles placed in a constant magnetic field is predicted. This effect is related to a symetry breaking in the system induced by the magnetic field which gives rise to preferential channels for the heat-transport by photon tunneling thanks to the particles anisotropy tuning.

  6. Pushing the Photon Limit

    NARCIS (Netherlands)

    Wientjes, Emilie; Renger, Jan; Cogdell, Richard; Hulst, van Niek F.

    2016-01-01

    Nanoantennas are well-known for their effective role in fluorescence enhancement, both in excitation and emission. Enhancements of 3-4 orders of magnitude have been reported. Yet in practice, the photon emission is limited by saturation due to the time that a molecule spends in singlet and especi

  7. Photonic curvilinear data processing

    Science.gov (United States)

    Browning, Clyde; Quaglio, Thomas; Figueiro, Thiago; Pauliac, Sébastien; Belledent, Jérôme; Fay, Aurélien; Bustos, Jessy; Marusic, Jean-Christophe; Schiavone, Patrick

    2014-10-01

    With more and more photonic data presence in e-beam lithography, the need for efficient and accurate data fracturing is required to meet acceptable manufacturing cycle time. Large photonic based layouts now create high shot count patterns for VSB based tools. Multiple angles, sweeping curves, and non-orthogonal data create a challenge for today's e-beam tools that are more efficient on Manhattan style data. This paper describes techniques developed and used for creating fractured data for VSB based pattern generators. Proximity Effect Correction is also applied during the fracture process, taking into account variable shot sizes to apply for accuracy and design style. Choosing different fracture routines for pattern data on-the-fly allows for fast and efficient processing. Data interpretation is essential for processing curvilinear data as to its size, angle, and complexity. Fracturing complex angled data into "efficient" shot counts is no longer practical as shot creation now requires knowledge of the actual data content as seen in photonic based pattern data. Simulation and physical printing results prove the implementations for accuracy and write times compared to traditional VSB writing strategies on photonic data. Geometry tolerance is used as part of the fracturing algorithm for controlling edge placement accuracy and tuning to different e-beam processing parameters.

  8. The Photonic Lantern

    CERN Document Server

    Birks, T A; Yerolatsitis, S; Leon-Saval, S G; Thomson, R R

    2015-01-01

    Photonic lanterns are made by adiabatically merging several single-mode cores into one multimode core. They provide low-loss interfaces between single-mode and multimode systems where the precise optical mapping between cores and individual modes is unimportant.

  9. Glasses for photonic applications

    NARCIS (Netherlands)

    Richardson, K.; Krol, D.M.; Hirao, K.

    2010-01-01

    Recent advances in the application of glassy materials in planar and fiber-based photonic structures have led to novel devices and components that go beyond the original thinking of the use of glass in the 1960s, when glass fibers were developed for low-loss, optical communication applications. Expl

  10. ALICE Photon Spectrometer

    CERN Multimedia

    Kharlov, Y

    2013-01-01

    PHOS provides unique coverage of the following physics topics: - Study initial phase of the collision of heavy nuclei via direct photons, - Jet-quenching as a probe of deconfinement, studied via high Pτ ϒ and π0, - Signals of chiral-symmetry restoration, - QCD studies in pp collisions via identified neutral spectra.

  11. Jet Production by Virtual Photons

    CERN Document Server

    Friberg, C; Friberg, Christer; Sjöstrand, Torbjörn

    2000-01-01

    The production of jets is studied in collisions of virtual photons, gamma*-p and gamma*-gamma*, specifically for applications at HERA and LEP2. Photon flux factors are convoluted with matrix elements involving either direct or resolved photons and, for the latter, with parton distributions of the photon. Special emphasis is put on the range of uncertainty in the modeling of the resolved component. The resulting model is compared with existing data.

  12. Biomedical photonics handbook biomedical diagnostics

    CERN Document Server

    Vo-Dinh, Tuan

    2014-01-01

    Shaped by Quantum Theory, Technology, and the Genomics RevolutionThe integration of photonics, electronics, biomaterials, and nanotechnology holds great promise for the future of medicine. This topic has recently experienced an explosive growth due to the noninvasive or minimally invasive nature and the cost-effectiveness of photonic modalities in medical diagnostics and therapy. The second edition of the Biomedical Photonics Handbook presents fundamental developments as well as important applications of biomedical photonics of interest to scientists, engineers, manufacturers, teachers, studen

  13. Photons, photon jets and dark photons at 750 GeV and beyond

    Energy Technology Data Exchange (ETDEWEB)

    Dasgupta, Basudeb [Tata Institute of Fundamental Research, Mumbai (India); Kopp, Joachim [Mainz Univ. (Germany). PRISMA Cluster of Excellence and Mainz Inst. for Theoretical Physics; Schwaller, Pedro [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2016-03-15

    In new physics searches involving photons at the LHC, one challenge is to distinguish scenarios with isolated photons from models leading to ''photon jets''. For instance, in the context of the 750 GeV diphoton excess, it was pointed out that a true diphoton resonance S → γγ can be mimicked by a process of the form pp → S → aa → 4γ, where S is a new scalar with a mass of 750 GeV and a is a light pseudoscalar decaying to two collinear photons. Photon jets can be distinguished from isolated photons by exploiting the fact that a large fraction of photons convert to an e{sup +}e{sup -} pair inside the inner detector. In this note, we quantify this discrimination power, and we study how the sensitivity of future searches differs for photon jets compared to isolated photons. We also investigate how our results depend on the lifetime of the particle(s) decaying to the photon jet. Finally, we discuss the extension to S → A'A' → e{sup +}e{sup -}e{sup +}e{sup -}, where there are no photons at all but the dark photon A' decays to e{sup +}e{sup -} pairs. Our results will be useful in future studies of the putative 750 GeV signal, but also more generally in any new physics search involving hard photons.

  14. Photons, photon jets, and dark photons at 750 GeV and beyond.

    Science.gov (United States)

    Dasgupta, Basudeb; Kopp, Joachim; Schwaller, Pedro

    2016-01-01

    In new physics searches involving photons at the LHC, one challenge is to distinguish scenarios with isolated photons from models leading to "photon jets". For instance, in the context of the 750 GeV diphoton excess, it was pointed out that a true diphoton resonance [Formula: see text] can be mimicked by a process of the form [Formula: see text], where S is a new scalar with a mass of 750 GeV and a is a light pseudoscalar decaying to two collinear photons. Photon jets can be distinguished from isolated photons by exploiting the fact that a large fraction of photons convert to an [Formula: see text] pair inside the inner detector. In this note, we quantify this discrimination power, and we study how the sensitivity of future searches differs for photon jets compared to isolated photons. We also investigate how our results depend on the lifetime of the particle(s) decaying to the photon jet. Finally, we discuss the extension to [Formula: see text], where there are no photons at all but the dark photon [Formula: see text] decays to [Formula: see text] pairs. Our results will be useful in future studies of the putative 750 GeV signal, but also more generally in any new physics search involving hard photons.

  15. Survey and Alignment of the 100MeV Linear Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Park, Bumsik; Kwon, Hyeokjung; Jang, Jiho; Kim, Hansung; Kim, Daeil; Cho, Yongsub [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-05-15

    The 100MeV linear accelerator was installed and under commissioning at the Gyeongju site. The 100MeV proton linac was developed by the KOMAC according to the survey work and the alignment process. 100MeV proton beam will be supplied to the users after the beam commissioning. KOMAC is developing a 100MeV high-duty-factor proton linac. Linac is composed with a 50keV proton injector, a 3MeV RFQ, DTL tanks and a beam dump. In this paper, the survey and alignment scheme are described. To install the accelerator, the align network was built and the survey work was accomplished. On the basis of the survey result, all of the accelerator components were installed in the tunnel with two laser trackers.

  16. Photons and photoneutrons spectra of a Linac of 15 MV; Espectros de fotones y fotoneutrones de un LINAC de 15 MV

    Energy Technology Data Exchange (ETDEWEB)

    Benites R, J. L.; Carrillo C, A. [Centro Estatal de Cancerologia de Nayarit, Av. Enfermeria, Fracc. Fray Junipero Serra, 63000 Tepic, Nayarit (Mexico); Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Calle Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico); Velazquez F, J. B., E-mail: jlbenitesr@prodigy.net.mx [Universidad Autonoma de Nayarit, Posgrado CBAP, Carretera Tepic Compostela Km. 9, Xalisco, Nayarit (Mexico)

    2011-10-15

    Using the Monte Carlo code MCNP-5, the photons and photoneutrons spectra generated in the head stock of the lineal accelerator (Linac) Varian of 15 MV of the Cancerology State of Nayarit were determined. For the calculations a heterogeneous head stock was modeled, more compatible with the work conditions. In the center of the head stock a tungsten target was located on a copper support, followed by the flattened filter. The photons and photoneutrons spectra were obtained accelerating electrons and making them collide against the target to produce photons by Bremsstrahlung, these photons were transported inside the head stock and the photons and photoneutrons spectra were calculated in a punctual detector located under the flattened filter and in the isocenter. The spectra were evaluated in punctual detectors that were located in the plane from the isocenter to the long of the X and Y axes each 20 cm, in an equidistant way, up to 2 m, so much in the longitudinal and transversal axes. In the calculations were used histories 5E(6) with the purpose of obtaining smaller uncertainties to 1%. It was found that the photons spectrum in the punctual detector inside the head stock presents a pick of 1.25 MeV in the energy interval of 0.5 and 1.5 MeV, later suffers a filtration and diminishes in asymptote form. This spectrum modifies when the beam reaches the isocenter, diminishing the low energy photons. Inside the head stock the photoneutrons spectrum shows a structure with two picks, one before 1 MeV and other after 1 MeV; this is for effect of the collimators geometry and the distance. Finally an increment of the total neutrons flow to 60 cm of distance of the isocenter on the Y axis was observed, due to the design geometry of the modeling heterogeneous head stock. (Author)

  17. Optimal moderator materials at various proton energies considering photon dose rate after irradiation for an accelerator-driven ⁹Be(p, n) boron neutron capture therapy neutron source.

    Science.gov (United States)

    Hashimoto, Y; Hiraga, F; Kiyanagi, Y

    2015-12-01

    We evaluated the accelerator beam power and the neutron-induced radioactivity of (9)Be(p, n) boron neutron capture therapy (BNCT) neutron sources having a MgF2, CaF2, or AlF3 moderator and driven by protons with energy from 8 MeV to 30 MeV. The optimal moderator materials were found to be MgF2 for proton energies less than 10 MeV because of lower required accelerator beam power and CaF2 for higher proton energies because of lower photon dose rate at the treatment position after neutron irradiation.

  18. Study on photon sensitivity of silicon diodes related to materials used for shielding

    Science.gov (United States)

    Moiseev, T.

    1999-08-01

    Large area silicon diodes used in electronic neutron dosemeters have a significant over-response to X- and gamma-rays, highly non-linear at photon energies below 200 keV. This over-response to photons is proportional to the diode's active area and strongly affects the neutron sensitivity of such dosemeters. Since silicon diodes are sensitive to light and electromagnetic fields, most diode detector assemblies are provided with a shielding, sometimes also used as radiation filter. In this paper, the influence of materials covering the diode's active area is investigated using the MCNP-4A code by estimating the photon induced pulses in a typical silicon wafer (300 μm thickness and 1 cm diameter) when provided with a front case cover. There have been simulated small-size diode front covers made of several materials with low neutron interaction cross-sections like aluminium, TEFLON, iron and lead. The estimated number of induced pulses in the silicon wafer is calculated for each type of shielding at normal photon incidence for several photon energies from 9.8 keV up to 1.15 MeV and compared with that in a bare silicon wafer. The simulated pulse height spectra show the origin of the photon-induced pulses in silicon for each material used as protective cover: the photoelectric effect for low Z front case materials at low-energy incident photons (up to about 65 keV) and the Compton and build-up effects for high Z case materials at higher photon energies. A simple means to lower and flatten the photon response of silicon diodes over an extended X- and gamma rays energy range is proposed by designing a composed photon filter.

  19. QCD analysis and effective temperature of direct photons in lead-lead collisions at the LHC

    CERN Document Server

    Klasen, M; König, F; Wessels, J P

    2014-01-01

    We present a systematic theoretical analysis of the ALICE measurement of low-$p_T$ direct-photon production in central lead-lead collisions at the LHC with a centre-of-mass energy of $\\sqrt{s_{NN}}=2.76$ TeV. Using next-to-leading order of perturbative QCD, we compute the relative contributions to prompt-photon production from different initial and final states and the theoretical uncertainties coming from independent variations of the renormalisation and factorisation scales, the nuclear parton densities and the fragmentation functions. Based on different fits to the unsubtracted and prompt-photon subtracted ALICE data, we consistently find an exponential, possibly thermal, photon spectrum from the quark-gluon plasma (or hot medium) with slope $T=304\\pm 58$ MeV and $309\\pm64$ MeV at $p_T\\in[0.8;2.2]$ GeV and $p_T\\in[1.5;3.5]$ GeV as well as a power-law ($p_T^{-4}$) behavior for $p_T>4$ GeV as predicted by QCD hard scattering.

  20. Few-photon optical diode

    CERN Document Server

    Roy, Dibyendu

    2010-01-01

    We propose a novel scheme of realizing an optical diode at the few-photon level. The system consists of a one-dimensional waveguide coupled asymmetrically to a two-level system. The two or multi-photon transport in this system is strongly correlated. We derive exactly the single and two-photon current and show that the two-photon current is asymmetric for the asymmetric coupling. Thus the system serves as an optical diode which allows transmission of photons in one direction much more efficiently than the opposite.

  1. Few-photon optical diode

    OpenAIRE

    Roy, Dibyendu

    2010-01-01

    We propose a novel scheme of realizing an optical diode at the few-photon level. The system consists of a one-dimensional waveguide coupled asymmetrically to a two-level system. The two or multi-photon transport in this system is strongly correlated. We derive exactly the single and two-photon current and show that the two-photon current is asymmetric for the asymmetric coupling. Thus the system serves as an optical diode which allows transmission of photons in one direction much more efficie...

  2. Photonic band gap materials

    Science.gov (United States)

    Cassagne, D.

    Photonic band gap materials Photonic band gap materials are periodic dielectric structures that control the propagation of electromagnetic waves. We describe the plane wave method, which allows to calculate the band structures of photonic crystals. By symmetry analysis and a perturbative approach, we predict the appearance of the low energy photonic band gaps of hexagonal structures. We propose new two-dimensional structures called graphite and boron nitride. Using a transfer matrix method, we calculate the transmission of the graphite structure and we show the crucial role of the coupling with external modes. We study the appearance of allowed modes in the photonic band gap by the introduction of localized defects in the periodicity. Finally, we discuss the properties of opals formed by self-organized silica microspheres, which are very promising for the fabrication of three-dimensional photonic crystals. Les matériaux à bandes interdites photoniques sont des structures diélectriques périodiques qui contrôlent la propagation des ondes électromagnétiques. Nous décrivons la méthode des ondes planes qui permet de calculer les structures de bandes des cristaux photoniques. Par une analyse de la symétrie et une approche perturbative, nous précisons les conditions d'existence des bandes interdites de basse énergie. Nous proposons de nouvelles structures bidimensionnelles appelées graphite et nitrure de bore. Grâce à une méthode de matrices de transfert, nous calculons la transmission de la structure graphite et nous mettons en évidence le rôle fondamental du couplage avec les modes extérieurs. Nous étudions l'apparition de modes permis dans la bande interdite grâce à l'introduction de défauts dans la périodicité. Enfin, nous discutons les propriétés des opales constituées de micro-billes de silice auto-organisées, qui sont très prometteuses pour la fabrication de cristaux photoniques tridimensionnels.

  3. A semiconductor photon-sorter

    CERN Document Server

    Bennett, A J; Ellis, D J P; Farrer, I; Ritchie, D A; Shields, A J

    2016-01-01

    Photons do not interact directly with each other, but conditional control of one beam by another can be achieved with non-linear optical media at high field intensities. It is exceedingly difficult to reach such intensities at the single photon level but proposals have been made to obtain effective interactions by scattering photons from single transitions. We report here effective interactions between photons created using a quantum dot weakly coupled to a cavity. We show that a passive single-photon non-linearity can modify the counting statistics of a Poissonian beam, sorting the photons in number. This is used to create strong correlations between detection events and sort polarisation correlated photons from an uncorrelated stream using a single spin. These results pave the way for optical switches operated by single quanta of light.

  4. Photonic-powered cable assembly

    Science.gov (United States)

    Sanderson, Stephen N.; Appel, Titus James; Wrye, IV, Walter C.

    2013-01-22

    A photonic-cable assembly includes a power source cable connector ("PSCC") coupled to a power receive cable connector ("PRCC") via a fiber cable. The PSCC electrically connects to a first electronic device and houses a photonic power source and an optical data transmitter. The fiber cable includes an optical transmit data path coupled to the optical data transmitter, an optical power path coupled to the photonic power source, and an optical feedback path coupled to provide feedback control to the photonic power source. The PRCC electrically connects to a second electronic device and houses an optical data receiver coupled to the optical transmit data path, a feedback controller coupled to the optical feedback path to control the photonic power source, and a photonic power converter coupled to the optical power path to convert photonic energy received over the optical power path to electrical energy to power components of the PRCC.

  5. Two photon physics. Personal recollection

    CERN Document Server

    Ginzburg, Ilya F

    2015-01-01

    The term two--photon processes is used for the reactions in which some system of particles is produced in collision of two photons, either real or virtual. In the study of these processes our main goal was to suggest approach, allowing to extract from the data information on proper two--photon process separating it from mechanism which responsible for the production of photons. Here I present my view for history of two--photon physics. I don't try to give complete review, concentrating mainly on works of our team (which cover essential part of the topic) and some colleagues. My citation is strongly incomplete. I cite here only papers which were essential in our understanding of the problems. The choice of presented details is the result of my discussions with Gleb Kotkin and Valery Serbo. 1. Prehistory. 2. Two photon processes at e^+e^- colliders. 3. Photon colliders. 4. Notes on physical program.

  6. Quantum Imaging with Undetected Photons

    CERN Document Server

    Lemos, Gabriela B; Cole, Garrett D; Ramelow, Sven; Lapkiewicz, Radek; Zeilinger, Anton

    2014-01-01

    Indistinguishable quantum states interfere, but the mere possibility of obtaining information that could distinguish between overlapping states inhibits quantum interference. We present a novel quantum imaging concept that relies on the indistinguishability of the possible sources of a photon that remains undetected. Our experiment uses pair creation in two separate down-conversion crystals. If a pair is created in the first crystal, the undetected photon passes the sample to be imaged, and its mode is made identical to that of an undetected photon created in the second crystal. Because of the pair correlation, the phase and amplitude information imprinted on the undetected photon is also carried by its brother photon, called the signal. Interference of the two signal beams, one arising from each crystal, then reveals the image. The photons passing through the object are never detected, and the signal photons that are detected never interact with the object. We demonstrate the power of the method by exhibitin...

  7. [Depth dose characteristics of photon beams released from a scanning-type racetrack microtron].

    Science.gov (United States)

    Sato, Tomoharu

    2002-06-01

    The MM50 is a racetrack microtron that can emit photon beams or electron beams up to 50 MeV. The MM22 using the scanning beam method and the MM22 using a flattening filter method both to flatten the emission field and a water phantom with particular function measurable of PDD etc. in an accelerator using the scanning beam method to make up the PDD curve of photon beams from the linear accelerator. The Clinac21EX was thus employed. The maximum depth of beam flux was shallow, the gradient of the flux decrement large, the surface dose large, and the estimated nominal energy low to the same nominal energy. From these findings, it can be said that thorough comprehension of the characteristics of beam flux properties for these units is necessary when photon beams are to be used.

  8. Depth dose characteristics of photon beams released from a scanning-type racetrack microtron

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Tomoharu [National Cancer Center, Tokyo (Japan). Hospital

    2002-06-01

    The MM50 is a racetrack microtron that can emit photon beams or electron beams up to 50 MeV. The MM22 using the scanning beam method and the MM22 using a flattening filter method both to flatten the emission field and a water phantom with particular function measurable of PDD etc. in an accelerator using the scanning beam method to make up the PDD curve of photon beams from the linear accelerator. The Clinac21EX was thus employed. The maximum depth of beam flux was shallow, the gradient of the flux decrement large, the surface dose large, and the estimated nominal energy low to the same nominal energy. From these findings, it can be said that thorough comprehension of the characteristics of beam flux properties for these units is necessary when photon beams are to be used. (author)

  9. PENELOPE, and algorithm and computer code for Monte Carlo simulation of electron-photon showers

    Energy Technology Data Exchange (ETDEWEB)

    Salvat, F.; Fernandez-Varea, J.M.; Baro, J.; Sempau, J.

    1996-10-01

    The FORTRAN 77 subroutine package PENELOPE performs Monte Carlo simulation of electron-photon showers in arbitrary for a wide energy range, from similar{sub t}o 1 KeV to several hundred MeV. Photon transport is simulated by means of the standard, detailed simulation scheme. Electron and positron histories are generated on the basis of a mixed procedure, which combines detailed simulation of hard events with condensed simulation of soft interactions. A simple geometry package permits the generation of random electron-photon showers in material systems consisting of homogeneous bodies limited by quadric surfaces, i.e. planes, spheres cylinders, etc. This report is intended not only to serve as a manual of the simulation package, but also to provide the user with the necessary information to understand the details of the Monte Carlo algorithm.

  10. PENELOPE, an algorithm and computer code for Monte Carlo simulation of electron-photon showers

    Energy Technology Data Exchange (ETDEWEB)

    Salvat, F.; Fernandez-Varea, J.M.; Baro, J.; Sempau, J.

    1996-07-01

    The FORTRAN 77 subroutine package PENELOPE performs Monte Carlo simulation of electron-photon showers in arbitrary for a wide energy range, from 1 keV to several hundred MeV. Photon transport is simulated by means of the standard, detailed simulation scheme. Electron and positron histories are generated on the basis of a mixed procedure, which combines detailed simulation of hard events with condensed simulation of soft interactions. A simple geometry package permits the generation of random electron-photon showers in material systems consisting of homogeneous bodies limited by quadric surfaces, i.e. planes, spheres, cylinders, etc. This report is intended not only to serve as a manual of the simulation package, but also to provide the user with the necessary information to understand the details of the Monte Carlo algorithm. (Author) 108 refs.

  11. Distribution of photon strength in nuclei by a method of two-step cascades

    Energy Technology Data Exchange (ETDEWEB)

    Becvar, F.; Cejnar, P. (Karlova Univ., Prague (Czechoslovakia). Fakulta Matematicko-Fyzikalni); Chrien, R.E. (Brookhaven National Lab., Upton, NY (USA)); Kopecky, J. (Netherlands Energy Research Foundation, Petten (Netherlands))

    1990-01-01

    The applicability of sum-coincidence measurements of two-step cascade {gamma}-ray spectra to the determination of photon strength functions at intermediate {gamma}-ray energies (3 or 4 MeV) is discussed. An experiment based on thermal neutron capture in Nd was undertaken at the Brookhaven National Laboratory High Flux Beam Reactor to test this model. To understand the role of various uncertainties in similar experiments a series of model calculations was performed. We present an analysis of our experimental data which demonstrates the high sensitivity of the method to E1 and M1 photon strength functions. Our experimental data are in sharp contradiction to those expected from an E1 photon strength distributed according to the classical Lorentzian form with an energy invariant damping width. An alternative distribution of Kadmenskij et al., which violates Brink's Hypothesis, is strongly preferred. 13 refs., 5 figs.

  12. Photonics an introduction

    CERN Document Server

    Reider, Georg A

    2016-01-01

    This book provides a comprehensive introduction into photonics, from the electrodynamic and quantum mechanic fundamentals to the level of photonic components and building blocks such as lasers, amplifiers, modulators, waveguides, and detectors. The book will serve both as textbook and as a reference work for the advanced student or scientist. Theoretical results are derived from basic principles with convenient, yet state-of-the-art mathematical tools, providing not only deeper understanding but also familiarization with formalisms used in the relevant technical literature and research articles. Among the subject matters treated are polarization optics, pulse and beam propagation, waveguides, light–matter interaction, stationary and transient behavior of lasers, semiconductor optics and lasers (including low-dimensional systems such as quantum wells), detector technology, photometry, and colorimetry. Nonlinear optics are elaborated comprehensively. The book is intended for both students of physics and elect...

  13. Extreme Photonics & Applications

    CERN Document Server

    Hall, Trevor J; Paredes, Sofia A

    2010-01-01

    "Extreme Photonics & Applications" arises from the 2008 NATO Advanced Study Institute in Laser Control & Monitoring in New Materials, Biomedicine, Environment, Security and Defense. Leading experts in the manipulation of light offered by recent advances in laser physics and nanoscience were invited to give lectures in their fields of expertise and participate in discussions on current research, applications and new directions. The sum of their contributions to this book is a primer for the state of scientific knowledge and the issues within the subject of photonics taken to the extreme frontiers: molding light at the ultra-finest scales, which represents the beginning of the end to limitations in optical science for the benefit of 21st Century technological societies. Laser light is an exquisite tool for physical and chemical research. Physicists have recently developed pulsed lasers with such short durations that one laser shot takes the time of one molecular vibration or one electron rotation in an ...

  14. Photonics meet digital art

    Science.gov (United States)

    Curticapean, Dan; Israel, Kai

    2014-09-01

    The paper focuses on the work of an interdisciplinary project between photonics and digital art. The result is a poster collection dedicated to the International Year of Light 2015. In addition, an internet platform was created that presents the project. It can be accessed at http://www.magic-of-light.org/iyl2015/index.htm. From the idea to the final realization, milestones with tasks and steps will be presented in the paper. As an interdisciplinary project, students from technological degree programs were involved as well as art program students. The 2015 Anniversaries: Alhazen (1015), De Caus (1615), Fresnel (1815), Maxwell (1865), Einstein (1905), Penzias Wilson, Kao (1965) and their milestone contributions in optics and photonics will be highlighted.

  15. Photons in a ball

    Energy Technology Data Exchange (ETDEWEB)

    Mueck, Wolfgang [Universita degli Studi di Napoli ' ' Federico II' ' , Dipartimento di Fisica ' ' Ettore Pancini' ' , Naples (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Napoli, Naples (Italy)

    2015-12-15

    The electromagnetic field inside a spherical cavity of large radius R is considered in the presence of stationary charge and current densities. R provides infra-red regularisation while maintaining gauge invariance. The quantum ground state of physical photons forming the magnetic field is found to be a coherent state with a definite mean occupation number. The electric field, which is determined by the Gauss law constraint, is maintained by a minimum uncertainty coherent state, according to the projection operator approach to the quantisation of constrained systems. The mean occupation number of this state is proportional to the square of the total charge. The results confirm formulae obtained previously from a calculation with a finite photon mass for infra-red regularisation. (orig.)

  16. Photons in a ball

    Energy Technology Data Exchange (ETDEWEB)

    Mück, Wolfgang, E-mail: mueck@na.infn.it [Dipartimento di Fisica “Ettore Pancini”, Università degli Studi di Napoli “Federico II”, Via Cintia, 80126, Naples (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Napoli, Via Cintia, 80126, Naples (Italy)

    2015-12-11

    The electromagnetic field inside a spherical cavity of large radius R is considered in the presence of stationary charge and current densities. R provides infra-red regularisation while maintaining gauge invariance. The quantum ground state of physical photons forming the magnetic field is found to be a coherent state with a definite mean occupation number. The electric field, which is determined by the Gauss law constraint, is maintained by a minimum uncertainty coherent state, according to the projection operator approach to the quantisation of constrained systems. The mean occupation number of this state is proportional to the square of the total charge. The results confirm formulae obtained previously from a calculation with a finite photon mass for infra-red regularisation.

  17. The ubiquitous photonic wheel

    CERN Document Server

    Aiello, Andrea

    2016-01-01

    A circularly polarized electromagnetic plane wave carries an electric field that rotates clockwise or counterclockwise around the propagation direction of the wave. According to the handedness of this rotation, its \\emph{longitudinal} spin angular momentum density is either parallel or antiparallel to the propagation of light. However, there are also light waves that are not simply plane and carry an electric field that rotates around an axis perpendicular to the propagation direction, thus yielding \\emph{transverse} spin angular momentum density. Electric field configurations of this kind have been suggestively dubbed "photonic wheels". It has been recently shown that photonic wheels are commonplace in optics as they occur in electromagnetic fields confined by waveguides, in strongly focused beams, in plasmonic and evanescent waves. In this work we establish a general theory of electromagnetic waves {propagating along a well defined direction, which carry} transverse spin angular momentum density. We show th...

  18. Nonlinear Photonic Crystal Fibers

    DEFF Research Database (Denmark)

    Hansen, Kim Per

    2004-01-01

    , leading to reduced mode confinement and dispersion flexibility. In this thesis, we treat the nonlinear photonic crystal fiber – a special sub-class of photonic crystal fibers, the core of which has a diameter comparable to the wavelength of the light guided in the fiber. The small core results in a large...... nonlinear coefficient and in various applications, it is therefore possible to reduce the required fiber lengths quite dramatically, leading to increased stability and efficiency. Furthermore, it is possible to design these fibers with zero-dispersion at previously unreachable wavelengths, paving the way...... for completely new applications, especially in and near the visible wavelength region. One such application is supercontinuum generation. Supercontinuum generation is extreme broadening of pulses in a nonlinear medium (in this case a small-core fiber), and depending on the dispersion of the fiber, it is possible...

  19. Natural photonic crystals

    Energy Technology Data Exchange (ETDEWEB)

    Vigneron, Jean Pol, E-mail: jean-pol.vigneron@fundp.ac.be [Research Center in Physics of Matter and Radiation (PMR), University of Namur (FUNDP), rue de Bruxelles, 61, B-5000 Namur (Belgium); Simonis, Priscilla [Research Center in Physics of Matter and Radiation (PMR), University of Namur (FUNDP), rue de Bruxelles, 61, B-5000 Namur (Belgium)

    2012-10-15

    Photonic structures appeared in nature several hundred millions years ago. In the living world, color is used for communication and this important function strongly impacts the individual chances of survival as well as the chances to reproduce. This has a statistical influence on species populations. Therefore, because they are involved in evolution, natural color-generating structures are - from some point of view - highly optimized. In this short review, a survey is presented of the development of natural photonic crystal-type structures occurring in insects, spiders, birds, fishes and other marine animals, in plants and more, from the standpoint of light-waves propagation. One-, two-, and three-dimensional structures will be reviewed with selected examples.

  20. Thermally induced photon splitting

    CERN Document Server

    Elmfors, P; Elmfors, Per; Skagerstam, Bo-Sture

    1998-01-01

    We calculate thermal corrections to the non-linear QED effective action for low-energy photon interactions in a background electromagnetic field. The high-temperature expansion shows that at $T \\gg m$ the vacuum contribution is exactly cancelled to all orders in the external field except for a non-trivial two-point function contribution. The high-temperature expansion derived reveals a remarkable cancellation of infrared sensitive contributions. As a result photon-splitting in the presence of a magnetic field is suppressed in the presence of an electron-positron QED-plasma at very high temperatures. In a cold and dense plasma a similar suppression takes place. At the same time Compton scattering dominates for weak fields and the suppression is rarely important in physical situations.

  1. Photon Stimulated Ion Desorption.

    Science.gov (United States)

    1982-03-03

    tentatively concluded that H2O is e.g. oxigen on W1lll).2 If an ionic model is molepularly adsorbed at 300K for exposures of a icatle, then after losing one...ely t- Le relatively covalent, namely variation in H+ PSID yield with photon energy dosed GaAsll0;. is shown in Fig. 1. There is clearly a thres

  2. Photonics and Optoelectronics

    Science.gov (United States)

    2013-03-07

    DARPA NNI/NNCO BRI (2D Materials & Devices Beyond Graphene – planning phase) LRIR PIs Szep – RY: PICS Quantum Information...vertically from plasmonic filters into Si CMOS image sensor diodes via PMMA dielectric and SiNx vertical light couplers - •Designed and implemented signal...model) gernot.pomrenke@afosr.af.mil Future: Metasurfaces/ Meta Photonics, Quantum Integrated Nanophotonics, Ultra Low Power, Graphene Optoelectronics

  3. Graphene Photonics and Optoelectronics

    OpenAIRE

    Bonaccorso, F.; Z. Sun; Hasan, T.; Ferrari, A. C.

    2010-01-01

    The richness of optical and electronic properties of graphene attracts enormous interest. Graphene has high mobility and optical transparency, in addition to flexibility, robustness and environmental stability. So far, the main focus has been on fundamental physics and electronic devices. However, we believe its true potential to be in photonics and optoelectronics, where the combination of its unique optical and electronic properties can be fully exploited, even in the absence of a bandgap, ...

  4. Photonic crystal optical memory

    Science.gov (United States)

    Lima, A. Wirth; Sombra, A. S. B.

    2011-06-01

    After several decades pushing the technology and the development of the world, the electronics is giving space for technologies that use light. We propose and analyze an optical memory embedded in a nonlinear photonic crystal (PhC), whose system of writing and reading data is controlled by an external command signal. This optical memory is based on optical directional couplers connected to a shared optical ring. Such a device can work over the C-Band of ITU (International Telecommunication Union).

  5. Illuminating WISPs with photons

    Energy Technology Data Exchange (ETDEWEB)

    Arias, Paola [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Chile Univ., Santiago (Chile). Facultad de Fisica; Ringwald, Andreas [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2011-10-15

    Physics beyond the Standard Model naturally gives rise to very light and weakly interacting particles, dubbed WISPs (Weakly Interacting Slim Particles). A prime example is the axion, that has eluded experimental detection for more than thirty years. In this talk we review some of the strongly motivated candidates for such particles, the observational hints for them and the present status of searches with photon regeneration experiments, as well as possible future improvements. (orig.)

  6. Photon Statistics of Single-Photon Quantum States in Real Single Photon Detection

    Institute of Scientific and Technical Information of China (English)

    李刚; 李园; 王军民; 彭堃墀; 张天才

    2004-01-01

    @@ Single photon detection (SPD) with high quantum efficiency has been widely used for measurement of different quantum states with different photon distributions.Based on the direct single SPD and double-SPD of HBT configuration, we discuss the effect of a real SPD on the photon statistics measurement and it shows that the measured photon distributions for different quantum states are corrected in different forms.The results are confirmed by experiment with the strongly attenuated coherent light and thermal light.This system can be used to characterize the photon statistics of the fluorescence light from single atom or single molecular.

  7. A Search for Single Photon Events in Neutrino Interactions

    CERN Document Server

    Kullenberg, C.T.; Dimmery, D.; Tian, X.C.; Autiero, D.; Gninenko, S.; Rubbia, A.; Alekhin, S.; Astier, P.; Baldisseri, A.; Baldo-Ceolin, M.; Banner, M.; Bassompierre, G.; Benslama, K.; Besson, N.; Bird, I.; Blumenfeld, B.; Bobisut, F.; Bouchez, J.; Boyd, S.; Bueno, A.; Bunyatov, S.; Camilleri, L.; Cardini, A.; Cattaneo, P.W.; Cavasinni, V.; Cervera-Villanueva, A.; Challis, R.; Chukanov, A.; Collazuol, G.; Conforto, G.; Conta, C.; Contalbrigo, M.; Cousins, R.; Degaudenzi, H.; De Santo, A.; Del Prete, T.; Di Lella, L.; do Couto e Silva, E.; Dumarchez, J.; Ellis, M.; Feldman, G.J.; Ferrari, R.; Ferrère, D.; Flaminio, V.; Fraternali, M.; Gaillard, J.-M.; Gangler, E.; Geiser, A.; Geppert, D.; Gibin, D.; Godley, A.; Gomez-Cadenas, J.-J.; Gosset, J.; Gößling, C.; Gouanère, M.; Grant, A.; Graziani, G.; Guglielmi, A.; Hagner, C.; Hernando, J.; Hurst, P.; Hyett, N.; Iacopini, E.; Joseph, C.; Juget, F.; Kent, N.; Klimov, O.; Kokkonen, J.; Kovzelev, A.; Krasnoperov, A.; Kim, J.J.; Kirsanov, M.; Kulagin, S.; Lacaprara, S.; Lachaud, C.; Lakić, B.; Lanza, A.; La Rotonda, L.; Laveder, M.; Letessier-Selvon, A.; Levy, J.M.; Ling, J.; Linssen, L.; Ljubičic, A.; Long, J.; Lupi, A.; Lyubushkin, V.; Marchionni, A.; Martelli, F.; Méchain, X.; Mendiburu, J.-P.; Meyer, J.-P.; Mezzetto, M.; Moorhead, G.F.; Naumov, D.; Nédélec, P.; Nefedov, Yu.; Nguyen-Mau, C.; Orestano, D.; Pastore, F.; Peak, L.S.; Pennacchio, E.; Pessard, H.; Petti, R.; Placci, A.; Polesello, G.; Pollmann, D.; Polyarush, A.; Poulsen, C.; Popov, B.; Rebuffi, L.; Rico, J.; Riemann, P.; Roda, C.; Salvatore, F.; Samoylov, O.; Schahmaneche, K.; Schmidt, B.; Schmidt, T.; Sconza, A.; Scott, A.M.; Seaton, M.B.; Sevior, M.; Sillou, D.; Soler, F.J.P.; Sozzi, G.; Steele, D.; Stiegler, U.; Stipčević, M.; Stolarczyk, Th.; Tareb-Reyes, M.; Taylor, G.N.; Tereshchenko, V.; Toropin, A.; Touchard, A.-M.; Tovey, S.N.; Tran, M.-T.; Tsesmelis, E.; Ulrichs, J.; Vacavant, L.; Valdata-Nappi, M.; Valuev, V.; Vannucci, F.; Varvell, K.E.; Veltri, M.; Vercesi, V.; Vidal-Sitjes, G.; Vieira, J.-M.; Vinogradova, T.; Weber, F.V.; Weisse, T.; Wilson, F.F.; Winton, L.J.; Wu, Q.; Yabsley, B.D.; Zaccone, H.; Zuber, K.; Zuccon, P.

    2012-01-01

    We present a search for neutrino-induced events containing a single, exclusive photon using data from the NOMAD experiment at the CERN SPS where the average energy of the neutrino flux is $\\simeq 25$ GeV. The search is motivated by an excess of electron-like events in the 200--475 MeV energy region as reported by the MiniBOONE experiment. In NOMAD, photons are identified via their conversion to $e^+e^-$ in an active target embedded in a magnetic field. The background to the single photon signal is dominated by the asymmetric decay of neutral pions produced either in a coherent neutrino-nucleus interaction, or in a neutrino-nucleon neutral current deep inelastic scattering, or in an interaction occurring outside the fiducial volume. All three backgrounds are determined {\\it in situ} using control data samples prior to opening the `signal-box'. In the signal region, we observe {\\bf 155} events with a predicted background of {\\bf 129.2 $\\pm$ 8.5 $\\pm$ 3.3}. We interpret this as null evidence for excess of single...

  8. Integrated photonic quantum walks

    Science.gov (United States)

    Gräfe, Markus; Heilmann, René; Lebugle, Maxime; Guzman-Silva, Diego; Perez-Leija, Armando; Szameit, Alexander

    2016-10-01

    Over the last 20 years quantum walks (QWs) have gained increasing interest in the field of quantum information science and processing. In contrast to classical walkers, quantum objects exhibit intrinsic properties like non-locality and non-classical many-particle correlations, which renders QWs a versatile tool for quantum simulation and computation as well as for a deeper understanding of genuine quantum mechanics. Since they are highly controllable and hardly interact with their environment, photons seem to be ideally suited quantum walkers. In order to study and exploit photonic QWs, lattice structures that allow low loss coherent evolution of quantum states are demanded. Such requirements are perfectly met by integrated optical waveguide devices that additionally allow a substantial miniaturization of experimental settings. Moreover, by utilizing the femtosecond direct laser writing technique three-dimensional waveguide structures are capable of analyzing QWs also on higher dimensional geometries. In this context, advances and findings of photonic QWs are discussed in this review. Various concepts and experimental results are presented covering, such as different quantum transport regimes, the Boson sampling problem, and the discrete fractional quantum Fourier transform.

  9. Photonic Molecule Lasers Revisited

    Science.gov (United States)

    Gagnon, Denis; Dumont, Joey; Déziel, Jean-Luc; Dubé, Louis J.

    2014-05-01

    Photonic molecules (PMs) formed by coupling two or more optical resonators are ideal candidates for the fabrication of integrated microlasers, photonic molecule lasers. Whereas most calculations on PM lasers have been based on cold-cavity (passive) modes, i.e. quasi-bound states, a recently formulated steady-state ab initio laser theory (SALT) offers the possibility to take into account the spectral properties of the underlying gain transition, its position and linewidth, as well as incorporating an arbitrary pump profile. We will combine two theoretical approaches to characterize the lasing properties of PM lasers: for two-dimensional systems, the generalized Lorenz-Mie theory will obtain the resonant modes of the coupled molecules in an active medium described by SALT. Not only is then the theoretical description more complete, the use of an active medium provides additional parameters to control, engineer and harness the lasing properties of PM lasers for ultra-low threshold and directional single-mode emission. We will extend our recent study and present new results for a number of promising geometries. The authors acknowledge financial support from NSERC (Canada) and the CERC in Photonic Innovations of Y. Messaddeq.

  10. Photonic Crystal Optical Tweezers

    CERN Document Server

    Wilson, Benjamin K; Bachar, Stephanie; Knouf, Emily; Bendoraite, Ausra; Tewari, Muneesh; Pun, Suzie H; Lin, Lih Y

    2009-01-01

    Non-invasive optical manipulation of particles has emerged as a powerful and versatile tool for biological study and nanotechnology. In particular, trapping and rotation of cells, cell nuclei and sub-micron particles enables unique functionality for various applications such as tissue engineering, cancer research and nanofabrication. We propose and demonstrate a purely optical approach to rotate and align particles using the interaction of polarized light with photonic crystal nanostructures to generate enhanced trapping force. With a weakly focused laser beam we observed efficient trapping and transportation of polystyrene beads with sizes ranging from 10 um down to 190 nm as well as cancer cell nuclei. In addition, we demonstrated alignment of non-spherical particles using a 1-D photonic crystal structure. Bacterial cells were trapped, rotated and aligned with optical intensity as low as 17 uW/um^2. Finite-difference time domain (FDTD) simulations of the optical near-field and far-field above the photonic c...

  11. Photonics Explorer Workshop

    Science.gov (United States)

    Prasad, Amrita; Debaes, Nathalie

    2014-07-01

    The Photonics Explorer is an intra-curricular educational kit developed in a European project with a pan-European collaboration of over 35 teachers and science education professors. Unlike conventional educational outreach kits, the Photonics Explorer is specifically designed to integrate seamlessly in school curricula and enhance and complement the teaching and learning of science and optics in the classroom. The kit equips teachers with class sets of experimental components, provided within a supporting didactic framework and is designed for lower and upper secondary students (12-18 years). The kit is provided completely free of charge to teachers in conjunction with teacher training courses. The workshop will provide an overview of the Photonics Explorer intra-curricular kit and give teachers the opportunity to work hands-on with the material and didactic content of two modules, `Light Signals' (lower secondary) and `Diffraction and Interference'(upper secondary). We also aim to receive feedback regarding the content, components and didactic framework from teachers from non- European countries, to understand the relevance of the kit for their teaching and the ability for such a kit to integrate into non-EU curricula.

  12. On the Origin of the MeV $\\gamma$-Ray Background

    CERN Document Server

    Stecker, F W; Done, C

    1999-01-01

    In this paper, we suggest a new hypothesis for explaining the spectrum of the extragalactic MeV gamma-ray background as observed by COMPTEL and SMM. We propose that both the flux level and spectrum can be accounted for as a superposition of non-thermal MeV tails in the spectra of Seyfert galaxies and other AGN. Although present detectors are not sensitive enough to obtain MeV data from individual extragalactic sources, indirect evidence in support of our hypothesis is found in OSSE and COMPTEL observations of the galactic black hole candidate Cygnus X-1.

  13. Measurement of flux-weight average cross-sections of natZn(γ,xn) reactions in the bremsstrahlung end-point energies of 50, 55, 60, and 65 MeV

    Science.gov (United States)

    Zaman, Muhammad; Kim, Guinyun; Naik, Haladhara; Kim, Kwangsoo; Cho, Young-Sik; Lee, Young-Ok; Shin, Sung-Gyun; Cho, Moo-Hyun; Kang, Yeong-Rok; Lee, Man-Woo

    2017-04-01

    The flux-weighted average cross-sections of (γ , xn) reactions on natZn induced by the bremsstrahlung end-point energies of 50, 55, 60, and 65 MeV have been determined by activation and off-line γ-ray spectrometric technique, using the 100 MeV electron linac at the Pohang Accelerator Laboratory (PAL), Pohang, Korea. The theoretical photon-induced reaction cross-sections of natZn as a function of photon energy were taken from TENDL-2014 nuclear data library based on TALYS 1.6 program. The flux-weighted average cross-sections were obtained from the literature data and the theoretical values of TENDL-2014 based on mono-energetic photon. The flux-weighted reaction cross-sections from the present work and literature data at different bremsstrahlung end-point energies are in good agreement with the theoretical values. It was found that the individual natZn(γ , xn) reaction cross-sections increase sharply from reaction threshold to certain values where the next reaction channel opens. There after it remains constant for a while, where the next reaction channel increases. Then it decreases slowly with increase of bremsstrahlung end-point energy due to opening of different reaction channels.

  14. Measurements of the Mass, Total Width and Two-Photon Partial Width of the $\\eta_{c}$ Meson

    CERN Document Server

    Brandenburg, G; Gao, Y S; Kim, D Y J; Wilson, R; Browder, T E; Li, Y; Rodríguez, J L; Yamamoto, H; Bergfeld, T; Eisenstein, B I; Ernst, J; Gladding, G E; Gollin, G D; Hans, R M; Johnson, E; Karliner, I; Marsh, M A; Palmer, M; Plager, C; Sedlack, C; Selen, M; Thaler, J J; Williams, J; Edwards, K W; Janicek, R; Patel, P M; Sadoff, A J; Ammar, R; Bean, A; Besson, D; Davis, R; Kwak, N; Zhao, X; Anderson, S; Frolov, V V; Kubota, Y; Lee, S J; Mahapatra, R; O'Neill, J J; Poling, R A; Riehle, T; Smith, A; Stepaniak, C J; Urheim, J; Ahmed, S; Alam, M S; Athar, S B; Jian, L; Ling, L; Saleem, M; Timm, S; Wappler, F; Anastassov, A; Duboscq, J E; Eckhart, E; Gan, K K; Gwon, C; Hart, T; Honscheid, K; Hufnagel, D; Kagan, H; Kass, R; Pedlar, T K; Schwarthoff, H; Thayer, J B; Von Törne, E; Zoeller, M M; Richichi, S J; Severini, H; Skubic, P L; Undrus, A; Chen, S; Fast, J; Hinson, J W; Lee, J; Miller, D H; Shibata, E I; Shipsey, I P J; Pavlunin, V; Cronin-Hennessy, D; Lyon, A L; Thorndike, E H; Jessop, C P; Marsiske, H; Perl, Martin Lewis; Savinov, V; Ugolini, D W; Zhou, X; Coan, T E; Fadeev, V; Maravin, Y; Narsky, I; Stroynowski, R; Ye, J; Wlodek, T; Artuso, M; Ayad, R; Boulahouache, C; Bukin, K; Dambasuren, E; Karamov, S; Majumder, G; Moneti, G C; Mountain, R; Schuh, S; Skwarnicki, T; Stone, S; Viehhauser, G; Wang, J C; Wolf, A; Wu, J; Kopp, S E; Mahmood, A H; Csorna, S E; Danko, I; McLean, K W; Marka, S; Xu, Z; Godang, R; Kinoshita, K; Lai, I C; Schrenk, S; Bonvicini, G; Cinabro, D; McGee, S; Perera, L P; Zhou, G J; Lipeles, E; Pappas, S P; Schmidtler, M; Shapiro, A; Sun, W M; Weinstein, A J; Würthwein, F; Jaffe, D E; Masek, G E; Paar, H P; Potter, E M; Prell, S; Sharma, V; Asner, D M; Eppich, A; Hill, T S; Morrison, R J; Briere, R A; Ferguson, T; Vogel, H; Behrens, B H; Ford, W T; Gritsan, A; Roy, J D; Smith, J G; Alexander, J P; Baker, R; Bebek, C; Berger, B E; Berkelman, K; Blanc, F; Boisvert, V; Cassel, David G; Dickson, M; Drell, P S; Ecklund, K M; Ehrlich, R; Foland, A D; Gaidarev, P B; Galik, R S; Gibbons, L K; Gittelman, B; Gray, S W; Hartill, D L; Heltsley, B K; Hopman, P I; Jones, C D; Kreinick, D L; Lohner, M; Magerkurth, A; Meyer, T O; Mistry, N B; Nordberg, E; Patterson, J R; Peterson, D; Riley, D; Thayer, J G; Thies, P G; Urner, D; Valant-Spaight, B L; Warburton, A; Avery, P; Prescott, C; Rubiera, A I; Yelton, J; Zheng, J

    2000-01-01

    Using 13.4 $fb^{-1}$ of data collected with the CLEO detector at the Cornell Electron Storage Ring, we have observed 300 events for the two-photon production of ground-state pseudo-scalar charmonium in the decay $\\eta_c$ -> $K_S K^{\\mp} \\pi^{\\pm}$. We have measured the $\\eta_c$ mass to be (2980.4 +- 2.3 (stat) +- 0.6 (sys)) MeV and its full width as (27.0 +- 5.8 (stat) +- 1.4 (sys)) MeV. We have determined the two-photon partial width of the $\\eta_c$ meson to be (7.6 +- 0.8 (stat) +- 0.4 (sys) +- 2.3 (br)) keV, with the last uncertainty associated with the decay branching fraction.

  15. Topological Photonic States

    Science.gov (United States)

    He, Cheng; Lin, Liang; Sun, Xiao-Chen; Liu, Xiao-Ping; Lu, Ming-Hui; Chen, Yan-Feng

    2014-01-01

    As exotic phenomena in optics, topological states in photonic crystals have drawn much attention due to their fundamental significance and great potential applications. Because of the broken time-reversal symmetry under the influence of an external magnetic field, the photonic crystals composed of magneto-optical materials will lead to the degeneracy lifting and show particular topological characters of energy bands. The upper and lower bulk bands have nonzero integer topological numbers. The gapless edge states can be realized to connect two bulk states. This topological photonic states originated from the topological property can be analogous to the integer quantum Hall effect in an electronic system. The gapless edge state only possesses a single sign of gradient in the whole Brillouin zone, and thus the group velocity is only in one direction leading to the one-way energy flow, which is robust to disorder and impurity due to the nontrivial topological nature of the corresponding electromagnetic states. Furthermore, this one-way edge state would cross the Brillouin center with nonzero group velocity, where the negative-zero-positive phase velocity can be used to realize some interesting phenomena such as tunneling and backward phase propagation. On the other hand, under the protection of time-reversal symmetry, a pair of gapless edge states can also be constructed by using magnetic-electric coupling meta-materials, exhibiting Fermion-like spin helix topological edge states, which can be regarded as an optical counterpart of topological insulator originating from the spin-orbit coupling. The aim of this article is to have a comprehensive review of recent research literatures published in this emerging field of photonic topological phenomena. Photonic topological states and their related phenomena are presented and analyzed, including the chiral edge states, polarization dependent transportation, unidirectional waveguide and nonreciprocal optical transmission, all

  16. Photonic band gap engineering in 2D photonic crystals

    Indian Academy of Sciences (India)

    Yogita Kalra; R K Sinha

    2006-12-01

    The polarization-dependent photonic band gaps (TM and TE polarizations) in two-dimensional photonic crystals with square lattices composed of air holes in dielectric and vice versa i.e., dielectric rods in air, using the plane-wave expansion method are investigated. We then study, how the photonic band gap size is affected by the changing ellipticity of the constituent air holes/dielectric rods. It is observed that the size of the photonic band gap changes with changing ellipticity of the constituent air holes/dielectric rods. Further, it is reported, how the photonic band gap size is affected by the change in the orientation of the constituent elliptical air holes/dielectric rods in 2D photonic crystals.

  17. Comparison of bactericidal efficiency of 7.5 MeV X-rays, gamma-rays, and 10 MeV e-beams

    Science.gov (United States)

    Song, Beom-Seok; Lee, Yunjong; Moon, Byeong-Geum; Go, Seon-Min; Park, Jong-Heum; Kim, Jae-Kyung; Jung, Koo; Kim, Dong-Ho; Ryu, Sang-Ryeol

    2016-08-01

    This study was performed to verify the feasibility of 7.5 MeV X-rays for food pasteurization through a comparison of the bactericidal efficiency with those of other sources for selected bacterial pathogens. No significant differences were observed between the overall bactericidal efficiency for beef-inoculated pathogens based on the uncertainty of the absorbed dose and variations in bacterial counts. This result supported that all three irradiation sources were effective for inactivation of food-borne bacteria and that 7.5 MeV X-rays may be used for food pasteurization.

  18. An improved time of flight gamma-ray telescope to monitor diffuse gamma-ray in the energy range 5 MeV - 50 MeV

    Science.gov (United States)

    Dacostafereiraneri, A.; Bui-Van, A.; Lavigne, J. M.; Sabaud, C.; Vedrenne, G.; Agrinier, B.; Gouiffes, C.

    1985-01-01

    A time of flight measuring device is the basic triggering system of most of medium and high energy gamma-ray telescopes. A simple gamma-ray telescope has been built in order to check in flight conditions the functioning of an advanced time of flight system. The technical ratings of the system are described. This telescope has been flown twice with stratospheric balloons, its axis being oriented at various Zenital directions. Flight results are presented for diffuse gamma-rays, atmospheric secondaries, and various causes of noise in the 5 MeV-50 MeV energy range.

  19. Synthetic Landau levels for photons.

    Science.gov (United States)

    Schine, Nathan; Ryou, Albert; Gromov, Andrey; Sommer, Ariel; Simon, Jonathan

    2016-06-30

    Synthetic photonic materials are an emerging platform for exploring the interface between microscopic quantum dynamics and macroscopic material properties. Photons experiencing a Lorentz force develop handedness, providing opportunities to study quantum Hall physics and topological quantum science. Here we present an experimental realization of a magnetic field for continuum photons. We trap optical photons in a multimode ring resonator to make a two-dimensional gas of massive bosons, and then employ a non-planar geometry to induce an image rotation on each round-trip. This results in photonic Coriolis/Lorentz and centrifugal forces and so realizes the Fock–Darwin Hamiltonian for photons in a magnetic field and harmonic trap. Using spatial- and energy-resolved spectroscopy, we track the resulting photonic eigenstates as radial trapping is reduced, finally observing a photonic Landau level at degeneracy. To circumvent the challenge of trap instability at the centrifugal limit, we constrain the photons to move on a cone. Spectroscopic probes demonstrate flat space (zero curvature) away from the cone tip. At the cone tip, we observe that spatial curvature increases the local density of states, and we measure fractional state number excess consistent with the Wen–Zee theory, providing an experimental test of this theory of electrons in both a magnetic field and curved space. This work opens the door to exploration of the interplay of geometry and topology, and in conjunction with Rydberg electromagnetically induced transparency, enables studies of photonic fractional quantum Hall fluids and direct detection of anyons.

  20. Synthetic Landau levels for photons

    Science.gov (United States)

    Schine, Nathan; Ryou, Albert; Gromov, Andrey; Sommer, Ariel; Simon, Jonathan

    2016-06-01

    Synthetic photonic materials are an emerging platform for exploring the interface between microscopic quantum dynamics and macroscopic material properties. Photons experiencing a Lorentz force develop handedness, providing opportunities to study quantum Hall physics and topological quantum science. Here we present an experimental realization of a magnetic field for continuum photons. We trap optical photons in a multimode ring resonator to make a two-dimensional gas of massive bosons, and then employ a non-planar geometry to induce an image rotation on each round-trip. This results in photonic Coriolis/Lorentz and centrifugal forces and so realizes the Fock-Darwin Hamiltonian for photons in a magnetic field and harmonic trap. Using spatial- and energy-resolved spectroscopy, we track the resulting photonic eigenstates as radial trapping is reduced, finally observing a photonic Landau level at degeneracy. To circumvent the challenge of trap instability at the centrifugal limit, we constrain the photons to move on a cone. Spectroscopic probes demonstrate flat space (zero curvature) away from the cone tip. At the cone tip, we observe that spatial curvature increases the local density of states, and we measure fractional state number excess consistent with the Wen-Zee theory, providing an experimental test of this theory of electrons in both a magnetic field and curved space. This work opens the door to exploration of the interplay of geometry and topology, and in conjunction with Rydberg electromagnetically induced transparency, enables studies of photonic fractional quantum Hall fluids and direct detection of anyons.

  1. Commissioning of a Varian Clinac iX 6 MV photon beam using Monte Carlo simulation

    Science.gov (United States)

    Dirgayussa, I. Gde Eka; Yani, Sitti; Rhani, M. Fahdillah; Haryanto, Freddy

    2015-09-01

    Monte Carlo modelling of a linear accelerator is the first and most important step in Monte Carlo dose calculations in radiotherapy. Monte Carlo is considered today to be the most accurate and detailed calculation method in different fields of medical physics. In this research, we developed a photon beam model for Varian Clinac iX 6 MV equipped with MilleniumMLC120 for dose calculation purposes using BEAMnrc/DOSXYZnrc Monte Carlo system based on the underlying EGSnrc particle transport code. Monte Carlo simulation for this commissioning head LINAC divided in two stages are design head Linac model using BEAMnrc, characterize this model using BEAMDP and analyze the difference between simulation and measurement data using DOSXYZnrc. In the first step, to reduce simulation time, a virtual treatment head LINAC was built in two parts (patient-dependent component and patient-independent component). The incident electron energy varied 6.1 MeV, 6.2 MeV and 6.3 MeV, 6.4 MeV, and 6.6 MeV and the FWHM (full width at half maximum) of source is 1 mm. Phase-space file from the virtual model characterized using BEAMDP. The results of MC calculations using DOSXYZnrc in water phantom are percent depth doses (PDDs) and beam profiles at depths 10 cm were compared with measurements. This process has been completed if the dose difference of measured and calculated relative depth-dose data along the central-axis and dose profile at depths 10 cm is ≤ 5%. The effect of beam width on percentage depth doses and beam profiles was studied. Results of the virtual model were in close agreement with measurements in incident energy electron 6.4 MeV. Our results showed that photon beam width could be tuned using large field beam profile at the depth of maximum dose. The Monte Carlo model developed in this study accurately represents the Varian Clinac iX with millennium MLC 120 leaf and can be used for reliable patient dose calculations. In this commissioning process, the good criteria of dose

  2. Programmable atom-photon quantum interface

    Science.gov (United States)

    Kurz, Christoph; Eich, Pascal; Schug, Michael; Müller, Philipp; Eschner, Jürgen

    2016-06-01

    We present the implementation of a programmable atom-photon quantum interface, employing a single trapped +40Ca ion and single photons. Depending on its mode of operation, the interface serves as a bidirectional atom-photon quantum-state converter, as a source of entangled atom-photon states, or as a quantum frequency converter of single photons. The interface lends itself particularly to interfacing ions with spontaneous parametric down-conversion-based single-photon or entangled-photon-pair sources.

  3. Neutron yield and induced radioactivity: a study of 235-MeV proton and 3-GeV electron accelerators.

    Science.gov (United States)

    Hsu, Yung-Cheng; Lai, Bo-Lun; Sheu, Rong-Jiun

    2016-01-01

    This study evaluated the magnitude of potential neutron yield and induced radioactivity of two new accelerators in Taiwan: a 235-MeV proton cyclotron for radiation therapy and a 3-GeV electron synchrotron serving as the injector for the Taiwan Photon Source. From a nuclear interaction point of view, neutron production from targets bombarded with high-energy particles is intrinsically related to the resulting target activation. Two multi-particle interaction and transport codes, FLUKA and MCNPX, were used in this study. To ensure prediction quality, much effort was devoted to the associated benchmark calculations. Comparisons of the accelerators' results for three target materials (copper, stainless steel and tissue) are presented. Although the proton-induced neutron yields were higher than those induced by electrons, the maximal neutron production rates of both accelerators were comparable according to their respective beam outputs during typical operation. Activation products in the targets of the two accelerators were unexpectedly similar because the primary reaction channels for proton- and electron-induced activation are (p,pn) and (γ,n), respectively. The resulting residual activities and remnant dose rates as a function of time were examined and discussed.

  4. High Precision Measurement of the Neutron Polarizabilities via Compton Scattering on Deuterium at Eγ=65 MeV

    Science.gov (United States)

    Sikora, Mark; Compton@HIGS Team

    2017-01-01

    The electric (αn) and magnetic (βn) polarizabilities of the neutron are fundamental properties arising from its internal structure which describe the nucleon's response to applied electromagnetic fields. Precise measurements of the polarizabilities provide crucial constraints on models of Quantum Chromodynamics (QCD) in the low energy regime such as Chiral Effective Field Theories as well as emerging ab initio calculations from lattice-QCD. These values also contribute the most uncertainty to theoretical determinations of the proton-neutron mass difference. Historically, the experimental challenges to measuring αn and βn have been due to the difficulty in obtaining suitable targets and sufficiently intense beams, leading to significant statistical uncertainties. To address these issues, a program of Compton scattering experiments on the deuteron is underway at the High Intensity Gamma Source (HI γS) at Duke University with the aim of providing the world's most precise measurement of αn and βn. We report measurements of the Compton scattering differential cross section obtained at an incident photon energy of 65 MeV and discuss the sensitivity of these data to the polarizabilities.

  5. Topological photonics: an observation of Landau levels for optical photons

    Science.gov (United States)

    Schine, Nathan; Ryou, Albert; Sommer, Ariel; Simon, Jonathan

    Creating photonic materials with nontrivial topological characteristics has seen burgeoning interest in recent years; however, a major route to topology, a magnetic field for continuum photons, has remained elusive. We present the first experimental realization of a bulk magnetic field for optical photons. By using a non-planar ring resonator, we induce an image rotation on each round trip through the resonator. This results in a Coriolis/Lorentz force and a centrifugal anticonfining force, the latter of which is cancelled by mirror curvature. Spatial- and energy- resolved spectroscopy tracks photonic eigenstates as residual trapping is reduced, and we observe photonic Landau levels as the eigenstates become degenerate. We will discuss the conical geometry of the resulting manifold for photon dynamics and present a measurement of the local density of states that is consistent with Landau levels on a cone. While our work already demonstrates an integer quantum Hall material composed of photons, we have ensured compatibility with strong photon-photon interactions, which will allow quantum optical studies of entanglement and correlation in manybody systems including fractional quantum Hall fluids. This work was supported by DOE, DARPA, and AFOSR.

  6. Photon technology. Laser process technology; Photon technology. Laser process gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    For developing laser process technology by interaction between substance and photon, the present state, system, R and D issues and proposal of such technology were summarized. Development of the photon technology aims at the modification of bonding conditions of substances by quantum energy of photon, and the new process technology for generating ultra- high temperature and pressure fields by concentrating photon on a minute region. Photon technology contributes to not only the conventional mechanical and thermal forming and removal machining but also function added machining (photon machining) in quantum level and new machining technology ranging from macro- to micro-machining, creating a new industrial field. This technology extends various fields from the basis of physics and chemistry to new bonding technology. Development of a compact high-quality high-power high-efficiency photon source, and advanced photon transmission technology are necessary. The basic explication of an unsolved physicochemical phenomenon related to photon and substance, and development of related application technologies are essential. 328 refs., 147 figs., 13 tabs.

  7. Tunable photonic Bloch oscillations in electrically modulated photonic crystals.

    Science.gov (United States)

    Wang, Gang; Huang, Ji Ping; Yu, Kin Wah

    2008-10-01

    We exploit theoretically the occurrence and tunability of photonic Bloch oscillations (PBOs) in one-dimensional photonic crystals (PCs) containing nonlinear composites. Because of the enhanced third-order nonlinearity (Kerr-type nonlinearity) of composites, photons undergo oscillations inside tilted photonic bands, which are achieved by the application of graded external-pump electric fields on such PCs, varying along the direction perpendicular to the surface of layers. The tunability of PBOs (including amplitude and period) is readily achieved by changing the field gradient. With an appropriate graded pump ac or dc electric field, terahertz PBOs can appear and cover a terahertz band in an electromagnetic spectrum.

  8. Tunable photonic Bloch oscillations in electrically modulated photonic crystals

    CERN Document Server

    Wang, Gang; Yu, Kin Wah

    2008-01-01

    We exploit theoretically the occurrence and tunability of photonic Bloch oscillations (PBOs) in one-dimensional photonic crystals (PCs) containing nonlinear composites. Because of the enhanced third-order nonlinearity (Kerr type nonlinearity) of composites, photons undergo oscillations inside tilted photonic bands, which are achieved by the application of graded external pump electric fields on such PCs, varying along the direction perpendicular to the surface of layers. The tunability of PBOs (including amplitude and period) is readily achieved by changing the field gradient. With an appropriate graded pump AC or DC electric field, terahertz PBOs can appear and cover a terahertz band in electromagnetic spectrum.

  9. Photon-photon interaction in structured QED vacuum

    CERN Document Server

    Hatsagortsyan, K Z

    2012-01-01

    In spatially structured strong laser fields, quantum electrodynamical vacuum behaves like a nonlinear Kerr medium with modulated third-order susceptibility where new coherent nonlinear effects arise due to modulation. We consider the enhancement of vacuum polarization and magnetization via coherent spatial vacuum effects in the photon-photon interaction process during scattering of a probe laser beam on parallel focused laser beams. Both processes of elastic and inelastic four wave-mixing in structured QED vacuum accompanied with Bragg interference are investigated. The phase-matching conditions and coherent effects in the presence of Bragg grating are analyzed for photon-photon scattering.

  10. Photon-photon refraction for TeV gamma rays

    CERN Document Server

    Dobrynina, Alexandra; Raffelt, Georg

    2014-01-01

    The propagation of TeV gamma rays can be strongly modified by B-field induced conversion to axion-like particles. The conversion rate depends on the photon dispersion relation which, at such high energies, is dominated by the B-field itself through the QED photon-photon interaction. However, ambient photons also contribute and the cosmic microwave background (CMB) dominates when B electron+positron it is the extra-galactic background light. Local radiation fields, e.g., the galactic star light, can be more important for dispersion than the CMB.

  11. Design study for a 500 MeV proton synchrotron with CSNS linac as an injector

    Science.gov (United States)

    Huang, Liang-Sheng; Ji, Hong-Fei; Wang, Sheng

    2016-09-01

    Using the China Spallation Neutron Source (CSNS) linac as the injector, a 500 MeV proton synchrotron is proposed for multidisciplinary applications, such as biology, material science and proton therapy. The synchrotron will deliver proton beam with energy from 80 MeV to 500 MeV. A compact lattice design has been worked out, and all the important beam dynamics issues have been investigated. The 80 MeV H- beam is stripped and injected into the synchrotron by using multi-turn injection. In order to continuously extraction the proton with small beam loss, an achromatic structure is proposed and a slow extraction method with RF knock-out is adopted and optimized.

  12. Performance of the 6 MeV injector for the Moscow racetrack microtron

    Science.gov (United States)

    Alimov, A. S.; Chepurnov, A. S.; Chubarov, O. V.; Gribov, I. V.; Ishkhanov, B. S.; Piskarev, I. M.; Rzhanov, A. G.; Sotnikov, M. A.; Surma, I. V.; Shumakov, A. V.; Shvedunov, V. I.; Tiunov, A. V.; Ushkanov, V. A.

    1993-03-01

    The 6 MeV injector for the Moscow racetrack microtron is described. The work presents the accelerator description, the rf power supply system and results of the computer simulation. The method of injector tuning and experimental results are discussed.

  13. Beam diagnostics measurements at 3 MeV of the LINAC4 H- beam at CERN

    CERN Document Server

    Zocca, F; Duraffourg, M; Focker, G J; Gerard, D; Kolad, B; Lenardon, F; Ludwig, M; Raich, U; Roncarolo, F; Sordet, M; Tan, J; Tassan-Viol, J; Vuitton, C; Feshenko, A

    2014-01-01

    As part of the CERN LHC injector chain upgrade, LINAC4 [1, 2] will accelerate H- ions to 160 MeV, replacing the old 50 MeV proton linac. The ion source, the Low Energy Beam Transfer (LEBT) line, the 3 MeV Radio Frequency Quadrupole and the Medium Energy Beam Transfer (MEBT) line hosting a chopper, have been commissioned in the LINAC4 tunnel. Diagnostic devices are installed in the LEBT and MEBT line and in a movable diagnostics test bench which is temporarily added to the MEBT exit. The paper gives an overview of all the instruments used, including beam current transformers, beam position monitors, wire scanners and wire grids for transverse profile measurements, a longitudinal bunch shape monitor and a slit-and-grid emittance meter. The instrumentation performance is discussed and the measurement results that allowed characterizing the 3 MeV beam in the LINAC4 tunnel are summarized.

  14. Monte Carlo simulation of MOSFET detectors for high-energy photon beams using the PENELOPE code

    Energy Technology Data Exchange (ETDEWEB)

    Panettieri, Vanessa [Institut de Tecniques Energetiques, Universitat Politecnica de Catalunya, Diagonal 647, 08028 Barcelona (Spain); Duch, Maria Amor [Institut de Tecniques Energetiques, Universitat Politecnica de Catalunya, Diagonal 647, 08028 Barcelona (Spain); Jornet, Nuria [Servei de RadiofIsica i Radioproteccio, Hospital de la Santa Creu i San Pau Sant Antoni Maria Claret 167, 08025 Barcelona (Spain); Ginjaume, Merce [Institut de Tecniques Energetiques, Universitat Politecnica de Catalunya, Diagonal 647, 08028 Barcelona (Spain); Carrasco, Pablo [Servei de RadiofIsica i Radioproteccio, Hospital de la Santa Creu i San Pau Sant Antoni Maria Claret 167, 08025 Barcelona (Spain); Badal, Andreu [Institut de Tecniques Energetiques, Universitat Politecnica de Catalunya, Diagonal 647, 08028 Barcelona (Spain); Ortega, Xavier [Institut de Tecniques Energetiques, Universitat Politecnica de Catalunya, Diagonal 647, 08028 Barcelona (Spain); Ribas, Montserrat [Servei de RadiofIsica i Radioproteccio, Hospital de la Santa Creu i San Pau Sant Antoni Maria Claret 167, 08025 Barcelona (Spain)

    2007-01-07

    The aim of this work was the Monte Carlo (MC) simulation of the response of commercially available dosimeters based on metal oxide semiconductor field effect transistors (MOSFETs) for radiotherapeutic photon beams using the PENELOPE code. The studied Thomson and Nielsen TN-502-RD MOSFETs have a very small sensitive area of 0.04 mm{sup 2} and a thickness of 0.5 {mu}m which is placed on a flat kapton base and covered by a rounded layer of black epoxy resin. The influence of different metallic and Plastic water(TM) build-up caps, together with the orientation of the detector have been investigated for the specific application of MOSFET detectors for entrance in vivo dosimetry. Additionally, the energy dependence of MOSFET detectors for different high-energy photon beams (with energy >1.25 MeV) has been calculated. Calculations were carried out for simulated 6 MV and 18 MV x-ray beams generated by a Varian Clinac 1800 linear accelerator, a Co-60 photon beam from a Theratron 780 unit, and monoenergetic photon beams ranging from 2 MeV to 10 MeV. The results of the validation of the simulated photon beams show that the average difference between MC results and reference data is negligible, within 0.3%. MC simulated results of the effect of the build-up caps on the MOSFET response are in good agreement with experimental measurements, within the uncertainties. In particular, for the 18 MV photon beam the response of the detectors under a tungsten cap is 48% higher than for a 2 cm Plastic water(TM) cap and approximately 26% higher when a brass cap is used. This effect is demonstrated to be caused by positron production in the build-up caps of higher atomic number. This work also shows that the MOSFET detectors produce a higher signal when their rounded side is facing the beam (up to 6%) and that there is a significant variation (up to 50%) in the response of the MOSFET for photon energies in the studied energy range. All the results have shown that the PENELOPE code system

  15. Photo-neutron reaction cross-section for {sup 93}Nb in the end-point bremsstrahlung energies of 12–16 and 45–70 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Naik, H. [Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Kim, G.N., E-mail: gnkim@knu.ac.kr [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Schwengner, R. [Institute of Radiation Physics, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden (Germany); Kim, K.; Zaman, M.; Tatari, M.; Sahid, M.; Yang, S.C. [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); John, R.; Massarczyk, R.; Junghans, A. [Institute of Radiation Physics, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden (Germany); Shin, S.G.; Key, Y. [Division of Advanced Nuclear Engineering, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of); Wagner, A. [Institute of Radiation Physics, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden (Germany); Lee, M.W. [Research Center, Dongnam Institute of Radiological and Medical Science, Busan 619-953 (Korea, Republic of); Goswami, A. [Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Cho, M.-H. [Division of Advanced Nuclear Engineering, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of)

    2013-10-23

    The photo-neutron cross-sections of {sup 93}Nb at the end-point bremsstrahlung energies of 12, 14 and 16 MeV as well as 45, 50, 55, 60 and 70 MeV have been determined by the activation and the off-line γ-ray spectrometric techniques using the 20 MeV electron linac (ELBE) at Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany, and 100 MeV electron linac at Pohang Accelerator Laboratory (PAL), Pohang, Korea. The {sup 93}Nb(γ, xn, x=1–4) reaction cross-sections as a function of photon energy were also calculated using computer code TALYS 1.4. The flux-weighted average values were obtained from the experimental and the theoretical (TALYS) values based on mono-energetic photons. The experimental values of present work are in good agreement with the flux-weighted theoretical values of TALYS 1.4 but are slightly higher than the flux-weighted experimental data of mono-energetic photons. It was also found that the theoretical and the experimental values of present work and literature data for the {sup 93}Nb(γ, xn) reaction cross-sections increase from the threshold values to a certain energy, where other reaction channels opens. However, the increase of {sup 93}Nb(γ, n) and {sup 93}Nb(γ, 2n) reaction cross-sections are sharper compared to {sup 93}Nb(γ, 3n) and {sup 93}Nb(γ, 4n) reaction cross-sections. The sharp increase of {sup 93}Nb(γ, n) and {sup 93}Nb(γ, 2n) reaction cross-sections from the threshold value up to 17–22 MeV is due to the Giant Dipole Resonance (GDR) effect besides the role of excitation energy. After a certain values, the individual {sup 93}Nb(γ, xn) reaction cross-sections decrease with increase of bremsstrahlung energy due to opening of other reaction channels.

  16. All-photonic quantum repeaters

    Science.gov (United States)

    Azuma, Koji; Tamaki, Kiyoshi; Lo, Hoi-Kwong

    2015-01-01

    Quantum communication holds promise for unconditionally secure transmission of secret messages and faithful transfer of unknown quantum states. Photons appear to be the medium of choice for quantum communication. Owing to photon losses, robust quantum communication over long lossy channels requires quantum repeaters. It is widely believed that a necessary and highly demanding requirement for quantum repeaters is the existence of matter quantum memories. Here we show that such a requirement is, in fact, unnecessary by introducing the concept of all-photonic quantum repeaters based on flying qubits. In particular, we present a protocol based on photonic cluster-state machine guns and a loss-tolerant measurement equipped with local high-speed active feedforwards. We show that, with such all-photonic quantum repeaters, the communication efficiency scales polynomially with the channel distance. Our result paves a new route towards quantum repeaters with efficient single-photon sources rather than matter quantum memories. PMID:25873153

  17. Quantum simulation with interacting photons

    Science.gov (United States)

    Hartmann, Michael J.

    2016-10-01

    Enhancing optical nonlinearities so that they become appreciable on the single photon level and lead to nonclassical light fields has been a central objective in quantum optics for many years. After this has been achieved in individual micro-cavities representing an effectively zero-dimensional volume, this line of research has shifted its focus towards engineering devices where such strong optical nonlinearities simultaneously occur in extended volumes of multiple nodes of a network. Recent technological progress in several experimental platforms now opens the possibility to employ the systems of strongly interacting photons, these give rise to as quantum simulators. Here we review the recent development and current status of this research direction for theory and experiment. Addressing both, optical photons interacting with atoms and microwave photons in networks of superconducting circuits, we focus on analogue quantum simulations in scenarios where effective photon-photon interactions exceed dissipative processes in the considered platforms.

  18. Photonic crystals in epitaxial semiconductors

    CERN Document Server

    La Rue, R M de

    1998-01-01

    The title of the paper uses the expression "photonic crystals". By photonic crystals, we mean regular periodic structures with a substantial refractive index variation in one-, two- or three- dimensional space. Such crystals can $9 exist naturally, for example natural opal, but are more typically fabricated by people. Under sufficiently strong conditions, i.e., sufficiently large refractive index modulation, correct size of structural components, and $9 appropriate rotational and translational symmetry, these crystals exhibit the characteristics of a photonic bandgap (PBG) structure. In a full photonic bandgap structure there is a spectral stop band for electromagnetic waves $9 propagating in any direction through the structure and with an arbitrary state of polarization. This behavior is of interest both from a fundamental viewpoint and from the point of view of novel applications in photonic devices. The $9 paper gives an outline review of work on photonic crystals carried out by the Optoelectronics Researc...

  19. Studies on Neutron, Photon (Bremsstrahlung and Proton Induced Fission of Actinides and Pre-Actinides

    Directory of Open Access Journals (Sweden)

    H. Naik

    2015-08-01

    Full Text Available We present the yields of various fission products determined in the reactor neutron, 3.7-18.1 MeV quasi-mono energetic neutron, 8-80 MeV bremsstrahlung and 20-45 MeV proton induced fission of 232Th and 238U using radiochemical and off-line beta or gamma ray counting. The yields of the fission products in the bremsstrahlung induced fission natPb and 209Bi with 50- 70 MeV and 2.5 GeV based on off-line gamma ray spectrometric technique were also presented. From the yields of fission products, the mass chains yields were obtained using charge distribution correction. From the mass yield distribution, the peak-to-valley (P/V ratio was obtained. The role of excitation energy on the peak-to-valley ratio and fine structure such as effect of shell closure proximity and even-odd effect of mass yield distribution were examined. The higher yields of the fission products around A=133-134, 138-140 and 143-144 and their complementary products explained from the nuclear structure effect and role of standard I and II mode of asymmetric fission. In the neutron, photon (bremsstrahlung and proton induced fission, the asymmetric mass distribution for actinides (Th, U and symmetric distribution for pre-actinides (Pb, Bi were explained from different type of potential fission barrier

  20. Photons, photon jets, and dark photons at 750 GeV and beyond

    Energy Technology Data Exchange (ETDEWEB)

    Dasgupta, Basudeb [Tata Institute of Fundamental Research, Mumbai (India); Kopp, Joachim [Johannes Gutenberg University, PRISMA Cluster of Excellence, Mainz Institute for Theoretical Physics, Mainz (Germany); Schwaller, Pedro [DESY, Hamburg (Germany)

    2016-05-15

    In new physics searches involving photons at the LHC, one challenge is to distinguish scenarios with isolated photons from models leading to ''photon jets''. For instance, in the context of the 750 GeV diphoton excess, it was pointed out that a true diphoton resonance S → γγ can be mimicked by a process of the form pp → S → aa → 4γ, where S is a new scalar with a mass of 750 GeV and a is a light pseudoscalar decaying to two collinear photons. Photon jets can be distinguished from isolated photons by exploiting the fact that a large fraction of photons convert to an e{sup +}e{sup -} pair inside the inner detector. In this note, we quantify this discrimination power, and we study how the sensitivity of future searches differs for photon jets compared to isolated photons. We also investigate how our results depend on the lifetime of the particle(s) decaying to the photon jet. Finally, we discuss the extension to S → A{sup '}A{sup '} → e{sup +}e{sup -}e{sup +}e{sup -}, where there are no photons at all but the dark photon A{sup '} decays to e{sup +}e{sup -} pairs. Our results will be useful in future studies of the putative 750 GeV signal, but also more generally in any new physics search involving hard photons. (orig.)

  1. High energy resolution characteristics on 14MeV neutron spectrometer for fusion experimental reactor

    Energy Technology Data Exchange (ETDEWEB)

    Iguchi, Tetsuo [Tokyo Univ., Tokai, Ibaraki (Japan). Nuclear Engineering Research Lab.; Takada, Eiji; Nakazawa, Masaharu

    1996-10-01

    A 14MeV neutron spectrometer suitable for an ITER-like fusion experimental reactor is now under development on the basis of a recoil proton counter telescope principle in oblique scattering geometry. To verify its high energy resolution characteristics, preliminary experiments are made for a prototypical detector system. The comparison results show reasonably good agreement and demonstrate the possibility of energy resolution of 2.5% in full width at half maximum for 14MeV neutron spectrometry. (author)

  2. Coulomb dissociation of {sup 8}B at 254 A MeV

    Energy Technology Data Exchange (ETDEWEB)

    Suemmerer, K.; Boue, F.; Baumann, T.; Geissel, H.; Hellstroem, M.; Koczon, P.; Schwab, E.; Schwab, W.; Senger, P.; Surowiecz, A. [Gesellschaft fuer Schwerionenforschung (GSI), Darmstadt (Germany); Iwasa, N.; Ozawa, A. [Gesellschaft fuer Schwerionenforschung (GSI), Darmstadt (Germany)]|[RIKEN Institute of Physical and Chemical Research, Saitama (Japan); Surowka, G. [Gesellschaft fuer Schwerionenforschung (GSI), Darmstadt (Germany)]|[Jagiellonian Univ., Krakow (Poland). Inst. of Physics; Blank, B.; Czajkowski, S.; Marchand, C.; Pravikoff, M.S. [Centre d`Etudes Nucleaires de Bordeaux-Gradignan, 33 (France); Foerster, A.; Lauer, F.; Oeschler, H.; Speer, J.; Sturm, C.; Uhlig, F.; Wagner, A. [Technische Univ. Darmstadt (Germany); Gai, M. [Connecticut Univ., Storrs, CT (United States). Dept. of Physics; Grosse, E. [Inst. fuer Kern- und Hadronenphysik, Forschungszentrum Rossendorf, Dresden (Germany); Kohlmeyer, B. [Philipps Univ., Marburg (Germany). Fachbereich Physik; Kulessa, R.; Walus, W. [Jagiellonian Univ., Krakow (Poland). Inst. of Physics; Motobayashi, T. [Rikkyo Univ., Tokyo (Japan). Dept. of Physics; Teranishi, T. [RIKEN Institute of Physical and Chemical Research, Saitama (Japan)

    1998-06-01

    As an alternative method for determining the astrophysical S-factor for the {sup 7}Be(p,{gamma}){sup 8}B reaction we have measured the Coulomb dissociation of {sup 8}B at 254 A MeV. From our preliminary results, we obtain good agreement with both the accepted direct-reaction measurements and the low-energy Coulomb dissociation study of Iwasa et al. performed at about 50 A MeV. (orig.)

  3. (n,Xn) measurements at 100 MeV. Recent developments and first results

    Energy Technology Data Exchange (ETDEWEB)

    Blideanu, V. [Lab. de Physique Corpusculaire, Caen (France); Blomgren, J.; Eudes, P.; Fontbonne, J.M.; Foucher, Y.; Guertin, A.; Hadad, F.; Hay, L.; Hildebrand, A.; Iltis, G.; Le Brun, C.; Lecolley, F.R.; Lecolley, J.F.; Lefort, T.; Louvel, M.; Mermod, P.; Marie, N.; Olsson, N.; Pomp, S.; Osterlund, M.; Prokoviev, A.V.

    2003-07-01

    In the framework of the HINDAS project, we have studied the feasibility of (n,Xn) measurements at intermediate energy (20-200 MeV). To achieve this goal, we have developed a new set-up and performed several experiments using the monoenergetic neutron beam facility at the Svedberg laboratory (Sweden). The performance of this set-up is illustrated by first results obtained in 100 MeV neutron-induced reactions on a lead target. (orig.)

  4. Measurement of Prompt Fission Neutron Spectrum of 238U at 2.8 MeV

    Institute of Scientific and Technical Information of China (English)

    HUANG; Han-xiong; RUAN; Xi-chao; REN; Jie; LI; Guang-wu; LUAN; Guang-yuan

    2015-01-01

    The prompt fission neutron spectrum(PFNS,Fig.1)of 238U was measured at 2.8MeV incident neutron energy by using the Cockcroft&Walton accelerator in China Institute of Atomic Energy(CIAE).The effect-to-background ratio was improved by increasing the amount of sample mass and adding an appropriate shielding.The final uncertainty of neutron energy spectrum is less than 20%below 10MeV region at an bin size

  5. Secondary particle yields from 400 MeV/u carbon ion and 250 MeV proton beams incident on thick targets

    Energy Technology Data Exchange (ETDEWEB)

    Ferrari, A. [Fondazione CNAO, Centro Nazionale di Adroterapia Oncologica, strada Campeggi, 27100 Pavia (Italy); Ferrarini, M., E-mail: michele.ferrarini@polimi.it [Fondazione CNAO, Centro Nazionale di Adroterapia Oncologica, strada Campeggi, 27100 Pavia (Italy); Politecnico di Milano, Dipartimento di Energia, Via Ponzio 34/3, 20133 Milano (Italy); Pelliccioni, M. [Fondazione CNAO, Centro Nazionale di Adroterapia Oncologica, strada Campeggi, 27100 Pavia (Italy); INFN, Laboratori Nazionali di Frascati, Via E. Fermi 40, 00044 Frascati (Italy)

    2011-07-01

    The double differential particle yield produced by hadron beams striking thick targets of copper, tungsten and ICRU tissue, have been determined by means of the Monte Carlo transport code FLUKA (version FLUKA 2008.3b.1). 400 MeV/u carbon ion and 250 MeV proton pencil beams have been considered. Secondary neutrons, photons, and protons have been scored. In order to validate the obtained data, a few simulations have been also repeated with MCNPX 2.6.0. The calculated results are presented and compared with the experimental data reported in literature. They should be very useful to solve a number of problems related to technological aspects of hadrontherapy.

  6. Hybrid amplitude determination in charged kaon photoproduction and comparison with partial waves analysis in the energy range of 1800 to 2300 MeV

    CERN Document Server

    Forozani, Gh

    2011-01-01

    The magnitude of four independent amplitudes are determined in charged kaon photoproduction in the energy range of 1500 to 2300MeV incident photon. Differential cross section and three polarization parameters are required for such amplitudes reconstruction at different kaon scattering angles. This analysis has indicated that the magnitudes of spin-flip amplitudes of the target nucleon dominate over the non-flip ones in all energies and scattering angles. The results have been compared with the solution of phase shift analysis sp98 at all energies. This analysis indicates that here is a good agreement between the present work and the results of phase shift analysis at all energies and scattering angles.

  7. Electron transport simulation in the range 1 keV-4 MeV for the purpose of high-resolution dosimetric application

    Energy Technology Data Exchange (ETDEWEB)

    Cobut, V. [Univ. de Cergy-Pontoise, Neuville/Oise (France). Lab. Pharmacophores Redox, Phytochimie et Radiobiologie; Cirioni, L.; Patau, J.P. [Univ. Paul Sabatier, Toulouse (France). Faculte de Pharmacie

    2001-07-01

    Experimental spectrometry and dosimetry can offer some reliable answers. However, they are not easy to implement in some specific situations. Furthermore, information on dose distributions cannot always be obtained with the desirable geometrical resolution. A way to get rid of these disadvantages consist in simulating every successive individual interactions suffered by electrons and photons along their path. We applied this principle to simulate the response of a detector placed in the field of beta-gamma sources, which maximum energy does not exceed 4 MeV. A part of this work is presented here, which concerns Monte Carlo simulation of electron transport in materials encountered in experimental dosimetric devices. Electrons were followed down to a cutoff energy of 1 keV. (orig.)

  8. Photonic zitterbewegung and its interpretation

    Institute of Scientific and Technical Information of China (English)

    Wang Zhi-Yong; Xiong Cai-Dong; Qiu Qi; Liao-Yun

    2012-01-01

    In terms of the volume-integrated Poynting vector,we present a quantum field-theory investigation of the zitterbewegung (ZB) of photons,and show that this ZB occurs only in the presence of virtual longitudinal and scalar photons.To present a heuristic explanation for such a ZB,by assuming that the space time is sufficiently close to the fiat Minkowski space,we show that the gravitational interaction can result in the ZB of photons.

  9. CERN manufactured hybrid photon detectors

    CERN Multimedia

    Maximilien Brice

    2004-01-01

    These hybrid photon detectors (HPDs) produce an electric signal from a single photon. An electron is liberated from a photocathode and accelerated to a silicon pixel array allowing the location of the photon on the cathode to be recorded. The electronics and optics for these devices have been developed in close collaboration with industry. HPDs have potential for further use in astrophysics and medical imaging.

  10. Negative refraction in photonic crystals

    OpenAIRE

    Baba, T.; Matsumoto, T.; Asatsuma, T.

    2008-01-01

    Photonic crystals are multidimensional periodic gratings, in which the light propagation is dominated by Bragg diffraction that appears to be refraction at the flat surfaces of the crystals. The refraction angle from positive to negative, perfectly or only partially obeying Snell’s law, can be tailored based on photonic band theory. Negative refraction enables novel prism, collimation, and lens effects. Because photonic crystals usually consist of two transparent media, these effects occur at...

  11. Generalized Fibonacci photon sieves.

    Science.gov (United States)

    Ke, Jie; Zhang, Junyong

    2015-08-20

    We successfully extend the standard Fibonacci zone plates with two on-axis foci to the generalized Fibonacci photon sieves (GFiPS) with multiple on-axis foci. We also propose the direct and inverse design methods based on the characteristic roots of the recursion relation of the generalized Fibonacci sequences. By switching the transparent and opaque zones, according to the generalized Fibonacci sequences, we not only realize adjustable multifocal distances but also fulfill the adjustable compression ratio of focal spots in different directions.

  12. Jaynes Cummings Photonic Superlattices

    CERN Document Server

    Longhi, Stefano

    2011-01-01

    A classical realization of the Jaynes-Cummings (JC) model, describing the interaction of a two-level atom with a quantized cavity mode, is proposed based on light transport in engineered waveguide superlattices. The optical setting enables to visualize in Fock space dynamical regimes not yet accessible in quantum systems, providing new physical insights into the deep strong coupling regime of the JC model. In particular, bouncing of photon number wave packets in Hilbert space and revivals of populations are explained as generalized Bloch oscillations in an inhomogeneous tight-binding lattice.

  13. Electromagnetic waves and photons

    CERN Document Server

    Hofmann, Ralf

    2015-01-01

    We explore how the thermal ground states of two mixing and pure SU(2) Yang-Mills theories, SU(2)$_{\\tiny\\mbox{CMB}}$ of scale $\\Lambda_{\\tiny\\mbox{CMB}}\\sim 10^{-4}\\,$eV and SU(2)$_{e}$ of scale $\\Lambda_{e}\\sim 5\\times 10^5\\,$eV, associate either wave or particle aspects to electromagnetic disturbances during thermalisation towards the photon gas of a blackbody, in realising the photoelectric effect, and through the frequency dependence of the monochromatic, nonthermal beam structure in Thomson/Compton scattering.

  14. Silicon active photonic devices

    Science.gov (United States)

    Dimitropoulos, Dimitrios

    Active photonic devices utilizing the optical nonlinearities of silicon have emerged in the last 5 years and the effort for commercial photonic devices in the material that has been the workhorse of electronics has been building up since. This dissertation presents the theory for some of these devices. We are concerned herein with CW lasers, amplifiers and wavelength converters that are based on the Raman effect. There have already been cursory experimental demonstrations of these devices and some of their limitations are already apparent. Most of the limitations observed are because of the appearance of effects that are competing with stimulated Raman scattering. Under the high optical powers that are necessary for the Raman effect (tens to hundrends of mW's) the process of optical two-photon (TPA) absorption occurs. The absorption of optical power that it causes itself is weak but in the process electrons and holes are generated which can further absorb light through the free-carrier absorption effect (FCA). The effective "lifetime" that these carriers have determines the magnitude of the FCA loss. We present a model for the carrier lifetime in Silicon-On-Insulator (SOI) waveguides and numerical simulations to understand how this critical parameter varies and how it can be controlled. A p-i-n junction built along SOI waveguides can help achieve lifetime of the order of 20--100 ps but the price one has to pay is on-chip electrical power consumption on the order of 100's of mWs. We model CW Raman lasers and we find that the carrier lifetime reduces the output power. If the carrier lifetime exceeds a certain "critical" value optical losses become overwhelming and lasing is impossible. As we show, in amplifiers, the nonlinear loss does not only result in diminished gain, but also in a higher noise figure. Finally the effect of Coherent anti-Stokes Raman scattering (CARS) is examined. The effect is important because with a pump frequency at 1434nm coherent power

  15. Nonresonance adiabatic photon trap

    CERN Document Server

    Popov, S S; Burdakov, A V; Ushkova, M Yu

    2016-01-01

    Concept of high efficiency photon storage based on adiabatic confinement between concave mirrors is presented and experimentally investigated. The approach is insensitive to typical for Fabri-Perot cells requirements on quality of accumulated radiation, tolerance of resonator elements and their stability. Experiments have been carried out with the trap, which consists from opposed concave cylindrical mirrors and conjugated with them spherical mirrors. In result, high efficiency for accumulation of radiation with large angular spread and spectrum width has been confirmed. As radiation source a commercial fiber laser has been used.

  16. Nanoimprinted photonic devices

    Science.gov (United States)

    Thomas, Jayan; Gangopadhyay, Palash; Munoz, Ramon; Peyghambarian, N.

    2010-08-01

    We introduce a simple yet efficient approach for nanoimprinting sub-50 nm dimensions starting from a low molecular weight plasticized polymer melt. This technique enabled us to successfully imprint versatile large area nanopatterns with high degrees of fidelity and rational control over the residual layers. The key advantage is its reliability in printing versatile nanostructures and nanophotonic devices doped with organic dyes owing to its low processing temperature. Since nanopatterns can be fabricated easily at low costs, this approach offers an easy pathway for achieving excellent nanoimprinted structures for a variety of photonic, electronic and biological research and applications.

  17. Spaceborne Photonics Institute

    Science.gov (United States)

    Venable, D. D.; Farrukh, U. O.; Han, K. S.; Hwang, I. H.; Jalufka, N. W.; Lowe, C. W.; Tabibi, B. M.; Lee, C. J.; Lyons, D.; Maclin, A.

    1994-01-01

    This report describes in chronological detail the development of the Spaceborne Photonics Institute as a sustained research effort at Hampton University in the area of optical physics. This provided the research expertise to initiate a PhD program in Physics. Research was carried out in the areas of: (1) modelling of spaceborne solid state laser systems; (2) amplified spontaneous emission in solar pumped iodine lasers; (3) closely simulated AM0 CW solar pumped iodine laser and repeatedly short pulsed iodine laser oscillator; (4) a materials spectroscopy and growth program; and (5) laser induced fluorescence and atomic and molecular spectroscopy.

  18. Estimate of the radiation source term for 18F production via thick H218O targets bombarded with 18 MeV protons

    Science.gov (United States)

    Cruzate, Juan Ángel

    2015-12-01

    The positron-emitting radionuclide most important from the point of view of radiation protection is 18F. This isotope is usually produced by bombarding 18O-enriched water with protons. Currently there are few experimental data on the radiation source term generated during these reactions. In addition, presently there is no theoretical estimates of this source term, for use in radiation protection, validated by experimental data. Up till now this term is calculated by using nuclear interactions' simulation codes, such as ALICE91. An estimate of the energy spectra for neutrons and photons, induced by 18 MeV protons on H218O target, have been calculated by using MCNPX code with cross sections from release 0 of ENDF/B VII library for all materials except 18O, for which TENDL-2012 library was used. This estimate was validated against a recent experiment carried out at the Japan Atomic Energy Agency (JAEA). The calculated spectra have generally well reproduced experiments. The results show that the calculated radiation source term may be used to estimate the neutron activation of the accelerator components and the cyclotron building, to calculate the cyclotron shielding, and to carry out radiation protection evaluations in general, for the case of cyclotrons producing 18F by means of the 18O(p,n)18F nuclear reactions, for proton energies up to 18 MeV.

  19. Ultrahigh brilliance quasi-monochromatic MeV γ-rays based on self-synchronized all-optical Compton scattering

    Science.gov (United States)

    Yu, Changhai; Qi, Rong; Wang, Wentao; Liu, Jiansheng; Li, Wentao; Wang, Cheng; Zhang, Zhijun; Liu, Jiaqi; Qin, Zhiyong; Fang, Ming; Feng, Ke; Wu, Ying; Tian, Ye; Xu, Yi; Wu, Fenxiang; Leng, Yuxin; Weng, Xiufeng; Wang, Jihu; Wei, Fuli; Yi, Yicheng; Song, Zhaohui; Li, Ruxin; Xu, Zhizhan

    2016-07-01

    Inverse Compton scattering between ultra-relativistic electrons and an intense laser field has been proposed as a major route to generate compact high-brightness and high-energy γ-rays. Attributed to the inherent synchronization mechanism, an all-optical Compton scattering γ-ray source, using one laser to both accelerate electrons and scatter via the reflection of a plasma mirror, has been demonstrated in proof-of-principle experiments to produce a x-ray source near 100 keV. Here, by designing a cascaded laser wakefield accelerator to generate high-quality monoenergetic e-beams, which are bound to head-on collide with the intense driving laser pulse via the reflection of a 20-um-thick Ti foil, we produce tunable quasi-monochromatic MeV γ-rays (33% full-width at half-maximum) with a peak brilliance of ~3 × 1022 photons s-1 mm-2 mrad-2 0.1% BW at 1 MeV. To the best of our knowledge, it is one order of magnitude higher than ever reported value of its kinds in MeV regime. This compact ultrahigh brilliance γ-ray source may provide applications in nuclear resonance fluorescence, x-ray radiology and ultrafast pump-probe nondestructive inspection.

  20. Tutorials in complex photonic media

    CERN Document Server

    Noginov, Mikhail A; McCall, Martin W; Zheludev, Nikolay I

    2010-01-01

    The field of complex photonic media encompasses many leading-edge areas in physics, chemistry, nanotechnology, materials science, and engineering. In Tutorials in Complex Photonic Media , leading experts have brought together 19 tutorials on breakthroughs in modern optics, such as negative refraction, chiral media, plasmonics, photonic crystals, and organic photonics. This text will help students, engineers, and scientists entering the field to become familiar with the interrelated aspects of the subject. It also serves well as a supplemental text in introductory and advanced courses on optica

  1. Hologram of a single photon

    Science.gov (United States)

    Chrapkiewicz, Radosław; Jachura, Michał; Banaszek, Konrad; Wasilewski, Wojciech

    2016-09-01

    The spatial structure of single photons is becoming an extensively explored resource to facilitate free-space quantum communication and quantum computation as well as for benchmarking the limits of quantum entanglement generation with orbital angular momentum modes or reduction of the photon free-space propagation speed. Although accurate tailoring of the spatial structure of photons is now routinely performed using methods employed for shaping classical optical beams, the reciprocal problem of retrieving the spatial phase-amplitude structure of an unknown single photon cannot be solved using complementary classical holography techniques that are known for excellent interferometric precision. Here, we introduce a method to record a hologram of a single photon that is probed by another reference photon, on the basis of a different concept of the quantum interference between two-photon probability amplitudes. As for classical holograms, the hologram of a single photon encodes the full information about the photon's ‘shape’ (that is, its quantum wavefunction) whose local amplitude and phase are retrieved in the demonstrated experiment.

  2. Recent photon results from ATLAS

    CERN Document Server

    Glasman, Claudia; The ATLAS collaboration

    2017-01-01

    The production of prompt isolated photons at hadron colliders provides a stringent test of perturbative QCD and can be used to probe the gluon density function of the proton. The ATLAS collaboration has performed precise measurements of the inclusive production o f isolated prompt photons at a center-of-mass energy of 13 TeV, differential in both rap idity and the photon transverse momentum. In addition, the integrated and differential c ross sections for isolated photon pair production 8 TeV have been measured. The results are compared with state-of-the-art theory predictions at NLO in QCD and with predictions of several MC generators.

  3. Dirac tensor with heavy photon

    Energy Technology Data Exchange (ETDEWEB)

    Bytev, V.V.; Kuraev, E.A. [Joint Institute of Nuclear Research, Moscow (Russian Federation). Bogoliubov Lab. of Theoretical Physics; Scherbakova, E.S. [Hamburg Univ. (Germany). 1. Inst. fuer Theoretische Physik

    2012-01-15

    For the large-angles hard photon emission by initial leptons in process of high energy annihilation of e{sup +}e{sup -} {yields} to hadrons the Dirac tensor is obtained, taking into account the lowest order radiative corrections. The case of large-angles emission of two hard photons by initial leptons is considered. This result is being completed by the kinematics case of collinear hard photons emission as well as soft virtual and real photons and can be used for construction of Monte-Carlo generators. (orig.)

  4. Photonic crystal fibers in biophotonics

    Science.gov (United States)

    Tuchin, Valery V.; Skibina, Julia S.; Malinin, Anton V.

    2011-12-01

    We observed recent experimental results in area of photonic crystal fibers appliance. Possibility of creation of fiberbased broadband light sources for high resolution optical coherence tomography is discussed. Using of femtosecond pulse laser allows for generation of optical radiation with large spectral width in highly nonlinear solid core photonic crystal fibers. Concept of exploitation of hollow core photonic crystal fibers in optical sensing is demonstrated. The use of photonic crystal fibers as "smart cuvette" gives rise to efficiency of modern optical biomedical analysis methods.

  5. Measurement of the Am241(n,2n) reaction cross section from 7.6 MeV to 14.5 MeV

    Science.gov (United States)

    Tonchev, A. P.; Angell, C. T.; Boswell, M.; Crowell, A. S.; Fallin, B.; Hammond, S.; Howell, C. R.; Hutcheson, A.; Karwowski, H. J.; Kelley, J. H.; Pedroni, R. S.; Tornow, W.; Becker, J. A.; Dashdorj, D.; Kenneally, J.; Macri, R. A.; Stoyer, M. A.; Wu, C. Y.; Bond, E.; Chadwick, M. B.; Fitzpatrick, J.; Kawano, T.; Rundberg, R. S.; Slemmons, A.; Vieira, D. J.; Wilhelmy, J. B.

    2008-05-01

    The (n,2n) cross section of the radioactive isotope Am241 (T1/2=432.6 y) has been measured in the incident neutron energy range from 7.6 to 14.5 MeV in steps of a few MeV using the activation technique. Monoenergetic neutron beams were produced via the H2(d,n)He3 reaction by bombarding a pressurized deuterium gas cell with an energetic deuteron beam at the TUNL 10-MV Van de Graaff accelerator facility. The induced γ-ray activity of Am240 was measured with high-resolution HPGe detectors. The cross section was determined relative to Al, Ni, and Au neutron activation monitor foils, measured in the same geometry. Good agreement is obtained with previous measurements at around 9 and 14 MeV, whereas for a large discrepancy is observed when our data are compared to those reported by Perdikakis near 11 MeV. Very good agreement is found with the END-B/VII evaluation, whereas the JENDL-3.3 evaluation is in fair agreement with our data.

  6. Measurement of (n,Xn) reaction cross sections at 96 MeV; Measure des sections efficaces (n,Xn) a 96 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Sagrado Garcia, Melle Inmaculada C. [Ecole Doctorale: SINEM, U.F.R. de Sciences, Universite de Caen/Basse-Normandie, Esplanade Paix14000 Caen (France)

    2006-10-15

    Nucleon induced reactions in the 20-200 MeV energy range are intensively studied since a long time. The evaporation and the pre-equilibrium processes correspond to an important contribution of the production cross section in these reactions. Several theoretical approaches have been proposed and their predictions must be tested. The experimental results shown in this work are the only complete set of data for the (n,Xn) reactions in this energy range. Neutron double differential cross section measurements using lead and iron targets for an incident neutron beam at 96 MeV were carried out at TSL Laboratory in Uppsala, Sweden. The measurements have been performed for the first time with an energy threshold of 2 MeV and for a wide angular range (15 angle - 98 angle). Neutrons have been detected using two independent setups, DECOI and DEMON and CLODIA and SCANDAL, in order to cover the whole energy range (2-100) MeV. The angular distributions, the differential cross sections and the total inelastic production cross sections have been calculated using the double differential cross sections. The comparison between the experimental data and the predictions given by two of the most popular simulation codes, GEANT3 and MCNPX, have been performed, as well as the comparison with the predictions of the microscopic simulation model DYWAN, selected for its treatment of nucleon-nucleon reactions. (author)

  7. Glueballs amass at RHIC and LHC Colliders! - The early quarkless 1st order phase transition at $T=270$ MeV - from pure Yang-Mills glue plasma to GlueBall-Hagedorn states

    CERN Document Server

    Stoecker, Horst; Schramm, Stefan; Senzel, Florian; Greiner, Carsten; Beitel, Maxim; Gallmeister, Kai; Gorenstein, Mark; Mishustin, Igor; Vasak, David; Steinheimer, Jan; Struckmeier, Juergen; Vovchenko, Volodymyr; Satarov, Leonid; Xu, Zhe; Zhuang, Pengfei; Csernai, Laszlo P; Sinha, Bikash; Raha, Sibaji; Biró, Tamás Sándor; Panero, Marco

    2016-01-01

    The early stage of high multiplicity pp, pA and AA collider is represented by a nearly quarkless, hot, deconfined pure gluon plasma. According to pure Yang-Mills Lattice Gauge Theory, this hot pure glue matter undergoes, at a high temperature, $T_c = 270$ MeV, a first order phase transition into a confined Hagedorn-GlueBall fluid. These new scenario should be characterized by a suppression of high $p_T$ photons and dileptons, baryon suppression and enhanced strange meson production. We propose to observe this newly predicted class of events at LHC and RHIC.

  8. Conversion of zero point energy into high-energy photons

    Energy Technology Data Exchange (ETDEWEB)

    Ivlev, B. I. [Universidad Autonoma de San Luis Potosi, Instituto de Fisica, Av. Manuel Nava No. 6, Zona Universitaria, 78290 San Luis Potosi, SLP (Mexico)

    2016-11-01

    An unusual phenomenon, observed in experiments is studied. X-ray laser bursts of keV energy are emitted from a metal where long-living states, resulting in population inversion, are totally unexpected. Anomalous electron-photon states are revealed to be formed inside the metal. These states are associated with narrow, 10{sup -11} cm, potential well created by the local reduction of zero point electromagnetic energy. In contrast to analogous van der Waals potential well, leading to attraction of two hydrogen atoms, the depth of the anomalous well is on the order of 1 MeV. The states in that well are long-living which results in population inversion and subsequent laser generation observed. The X-ray emission, occurring in transitions to lower levels, is due to the conversion of zero point electromagnetic energy. (Author)

  9. Radiochemical photon activation analysis of Halogens in meteorites

    Energy Technology Data Exchange (ETDEWEB)

    Oura, Yasuji; Latif, S.A.; Setoguchi, Mina; Nakamoto, Tomoshi; Ebihara, Mitsuru; Nakahara, Hiromichi [Tokyo Metropolitan Univ. (Japan). Faculty of Science; Ohtsuki, Tsutomu

    1999-12-01

    Halogens (F, Cl, Br and I) in meteorites and rocks are determined by a radiochemical photon activation analysis (RPAA) and compared with that of NPAA. We tried to determine all halogen elements at one time by one irradiation with 20 or 30 MeV maximum energy (E{sub 0}) by controlling irradiation for 2 or 6 hours with cooling. Average current is about 110 {mu}A. After irradiation, the sample was separated by radiochemical analysis. Allende meteorite, JR-I and d-41-7 were analyzed. The value of F, Cl and Br showed good reproducibility and agreed with the value in the reference. However, I showed small value. It may indicate volatilizing of I. (S.Y.)

  10. Photon Differentials in Space and Time

    DEFF Research Database (Denmark)

    Schjøth, Lars; Frisvad, Jeppe Revall; Erleben, Kenny;

    2011-01-01

    We present a novel photon mapping algorithm for animations. We extend our previous work on photon differentials [12] with time differentials. The result is a first order model of photon cones in space an time that effectively reduces the number of required photons per frame as well as efficiently...... reduces temporal aliasing without any need for in-between-frame photon maps....

  11. Direct Writing of Photonic Structures by Two-Photon Polymerization

    Directory of Open Access Journals (Sweden)

    Li Yan

    2013-11-01

    Full Text Available Single-mode dielectric-loaded surface plasmon-polariton nanowaveguides with strong mode confinement at excitation wavelength of 830 nm and high-Q polymer whispering gallery mode microcavities with surface roughness less than 12 nm have been directly written by two-photon polymerization, which pave the way to fabricate 3D plasmonic photonic structures by direct laser writing.

  12. Study of the photon identification efficiency with ALICE photon spectrometer

    Institute of Scientific and Technical Information of China (English)

    MAO Ya-Xian; ZHOU Dai-Cui; XU Chun-Cheng; YIN Zhong-Bao

    2008-01-01

    The efficiency for the detection and identification of photons with the ALICE PHOton Spectrometer PHOS has been studied with the Monte-Carlo generated data. In particular, the influence on the efficiency of the PHOS-module edge-effect and of the material in front of PHOS have been examined.

  13. Sidewall roughness measurement of photonic wires and photonic crystals

    DEFF Research Database (Denmark)

    Svalgaard, Mikael; Frandsen, Lars Hagedorn; Garnæs, Jørgen;

    2007-01-01

    The performance of nanophotonic building blocks such as photonic wires and photonic crystals are rapidly improving, with very low propagation loss and very high cavity Q-factors being reported. In order to facilitate further improvements in performance the ability to quantitatively measure...

  14. Quantum photonics with quantum dots in photonic wires

    DEFF Research Database (Denmark)

    Munsch, Mathieu; Kuhlmann, Andreas; Cadeddu, Davide;

    2016-01-01

    We present results from the spectroscopy of a single quantum dot in a photonic wire. The device presents a high photon extraction efficiency, and strong hybrid coupling to mechanical modes. We use resonance fluorescence to probe the emitter’s properties with the highest sensitivity. Weperform...

  15. Silicon photonics manufacturing.

    Science.gov (United States)

    Zortman, William A; Trotter, Douglas C; Watts, Michael R

    2010-11-08

    Most demonstrations in silicon photonics are done with single devices that are targeted for use in future systems. One of the costs of operating multiple devices concurrently on a chip in a system application is the power needed to properly space resonant device frequencies on a system's frequency grid. We asses this power requirement by quantifying the source and impact of process induced resonant frequency variation for microdisk resonators across individual die, entire wafers and wafer lots for separate process runs. Additionally we introduce a new technique, utilizing the Transverse Electric (TE) and Transverse Magnetic (TM) modes in microdisks, to extract thickness and width variations across wafers and dice. Through our analysis we find that a standard six inch Silicon on Insulator (SOI) 0.35 μm process controls microdisk resonant frequencies for the TE fundamental resonances to within 1 THz across a wafer and 105 GHz within a single die. Based on demonstrated thermal tuner technology, a stable manufacturing process exhibiting this level of variation can limit the resonance trimming power per resonant device to 231 μW. Taken in conjunction with the power to compensate for thermal environmental variations, the expected power requirement to compensate for fabrication-induced non-uniformities is 17% of that total. This leads to the prediction that thermal tuning efficiency is likely to have the most dominant impact on the overall power budget of silicon photonics resonator technology.

  16. Octonacci photonic quasicrystals

    Science.gov (United States)

    Brandão, E. R.; Costa, C. H.; Vasconcelos, M. S.; Anselmo, D. H. A. L.; Mello, V. D.

    2015-08-01

    We study theoretically the transmission spectra in one-dimensional photonic quasicrystals, made up of SiO2(A) and TiO2(B) materials, organized following the Octonacci sequence, where the nth-stage of the multilayer Sn is given by the rule Sn =Sn-1Sn-2Sn-1 , for n ⩾ 3 and with S1 = A and S2 = B . The expression for transmittance was obtained by employing a theoretical calculation based on the transfer-matrix method. For normally incident waves, we observe that, for a same generation, the transmission spectra for transverse electric (TE) and transverse magnetic (TM) waves are equal, at least qualitatively, and they present a scaling property where a self-similar behavior is obtained, as an evidence that these spectra are fractals. The spectra show regions where the omnidirectional band gaps emerges for specific generations of Octonacci photonic structure, except to TM waves. For TE waves, we note that all of them have almost the same width, for different generations. We also report the localization of modes as a consequence of the quasiperiodicity of the heterostructure.

  17. The ubiquitous photonic wheel

    Science.gov (United States)

    Aiello, Andrea; Banzer, Peter

    2016-08-01

    A circularly polarized electromagnetic plane wave carries an electric field that rotates clockwise or counterclockwise around the propagation direction of the wave. According to the handedness of this rotation, its longitudinal spin angular momentum (AM) density is either parallel or antiparallel to the propagation of light. However, there are also light waves that are not simply plane and carry an electric field that rotates around an axis perpendicular to the propagation direction, thus yielding transverse spin AM density. Electric field configurations of this kind have been suggestively dubbed ‘photonic wheels’. It has been recently shown that photonic wheels are commonplace in optics as they occur in electromagnetic fields confined by waveguides, in strongly focused beams, in plasmonic and evanescent waves. In this work we establish a general theory of electromagnetic waves propagating along a well defined direction, and carrying transverse spin AM density. We show that depending on the shape of these waves, the spin density may be either perpendicular to the mean linear momentum (globally transverse spin) or to the linear momentum density (locally transverse spin). We find that the latter case generically occurs only for non-diffracting beams, such as the Bessel beams. Moreover, we introduce the concept of meridional Stokes parameters to operationally quantify the transverse spin density. To illustrate our theory, we apply it to the exemplary cases of Bessel beams and evanescent waves. These results open a new and accessible route to the understanding, generation and manipulation of optical beams with transverse spin AM density.

  18. The Panofsky ratio, and the response of the PIBETA calorimeter to photons and positrons

    Science.gov (United States)

    Slocum, Penelope Lee

    1999-07-01

    A precise measurement of the pion beta decay rate will allow accurate testing of the unitarity of the Cabbibo- Kobayashi-Maskawa quark mixing matrix, and of the Conserved Vector Current Hypothesis. The PIBETA collaboration intends to measure this decay rate with an accuracy of better than 0.5%, using a calorimeter comprised of 240 pure CsI crystals. Extensive calibrations of the CsI crystals have been done using cosmic muons. Further studies of the calorimeter response have been made using monoenergetic 70 MeV beam positions, and using the box spectrum of photons ranging in energy from 55-83 MeV from the single charge exchange reaction p- p-->p0n-->g gn . Finally, a measurement of the Panofsky Ratio, defined as the ratio of the rate of single charge exchange to that of radiative pion capture p-p-->gn in pionic hydrogen, has been made.

  19. Search for a dark photon in the $\\pi^0 \\to e^+e^-\\gamma$ decay

    CERN Document Server

    :,; Augustyniak, W; Bardan, W; Bashkanov, M; Bergmann, F S; Berłowski, M; Bhatt, H; Bondar, A; Büscher, M; Calén, H; Ciepał, I; Clement, H; Coderre, D; Czerwiński, E; Demmich, K; Doroshkevich, E; Engels, R; Erven, W; Eyrich, W; Fedorets, P; Föhl, K; Fransson, K; Goldenbaum, F; Goslawski, P; Goswami, A; Grigoryev, K; Gullström, C -O; Hauenstein, F; Heijkenskjöld, L; Hejny, V; Hinterberger, F; Hodana, M; Höistad, B; Jany, A; Jany, B R; Jarczyk, L; Johansson, T; Kamys, B; Kemmerling, G; Khan, F A; Khoukaz, A; Kistryn, S; Klaja, J; Kleines, H; Kłos, B; Krapp, M; Krzemień, W; Kulessa, P; Kupść, A; Kuzmin, A; Lalwani, K; Lersch, D; Li, L; Lorentz, B; Magiera, A; Maier, R; Marciniewski, P; Mariański, B; Meißner, U -G; Mikirtychiants, M; Morsch, H -P; Moskal, P; Nandi, B K; Ohm, H; Ozerianska, I; del Rio, E Perez; Piskunov, N; Pluciński, P; Podkopał, P; Prasuhn, D; Pricking, A; Pszczel, D; Pysz, K; Pyszniak, A; Redmer, C F; Ritman, J; Roy, A; Rudy, Z; Sawant, S; Schadmand, S; Schmidt, A; Sefzick, T; Serdyuk, V; Shah, N; Shwartz, B; Siemaszko, M; Siudak, R; Skorodko, T; Skurzok, M; Smyrski, J; Sopov, V; Stassen, R; Stepaniak, J; Stephan, E; Sterzenbach, G; Stockhorst, H; Ströher, H; Szczurek, A; Tolba, T; Trzciński, A; Varma, R; Wagner, G J; Wȩglorz, W; Wirzba, A; Wolke, M; Wrońska, A; Wüstner, P; Wurm, P; Yamamoto, A; Zabierowski, J; Zieliński, M J; Zipper, W; Złomańczuk, J; Żuprański, P; Żurek, M

    2013-01-01

    The presently world largest data sample of pi0 --> gamma e+e- decays containing nearly 5E5 events was collected using the WASA detector at COSY. A search for a dark photon U produced in the pi0 --> gamma U --> gamma e+e- decay from the pp-->pp\\pi^0 reaction was carried out. An upper limit on the square of the U-gamma mixing strength parameter epsilon^2 of 5e-6 at 90% CL was obtained for the mass range 30 MeV MeV. This result together with other recent experimental limits significantly reduces the M_U vs. \\epsilon^2 parameter space preferred by the measured value of the muon anomalous magnetic moment.

  20. Robust Adaptive Photon Tracing using Photon Path Visibility

    DEFF Research Database (Denmark)

    Hachisuka, Toshiya; Jensen, Henrik Wann

    2011-01-01

    We present a new adaptive photon tracing algorithm which can handle illumination settings that are considered difficult for photon tracing approaches such as outdoor scenes, close-ups of a small part of an illuminated region, and illumination coming through a small gap. The key contribution in our...... algorithm is the use of visibility of photon path as the importance function which ensures that our sampling algorithm focuses on paths that are visible from the given viewpoint. Our sampling algorithm builds on two recent developments in Markov chain Monte Carlo methods: adaptive Markov chain sampling...... and replica exchange. Using these techniques, each photon path is adaptively mutated and it explores the sampling space efficiently without being stuck at a local peak of the importance function. We have implemented this sampling approach in the progressive photon mapping algorithm which provides visibility...

  1. Spin photonics and spin-photonic devices with dielectric metasurfaces

    CERN Document Server

    Liu, Yachao; Ke, Yougang; Zhou, Xinxing; Luo, Hailu; Wen, Shuangchun

    2015-01-01

    Dielectric metasurfaces with spatially varying birefringence and high transmission efficiency can exhibit exceptional abilities for controlling the photonic spin states. We present here some of our works on spin photonics and spin-photonic devices with metasurfaces. We develop a hybrid-order Poincare sphere to describe the evolution of spin states of wave propagation in the metasurface. Both the Berry curvature and the Pancharatnam-Berry phase on the hybrid-order Poincare sphere are demonstrated to be proportional to the variation of total angular momentum. Based on the spin-dependent property of Pancharatnam-Berry phase, we find that the photonic spin Hall effect can be observed when breaking the rotational symmetry of metasurfaces. Moreover, we show that the dielectric metasurfaces can provide great flexibility in the design of novel spin-photonic devices such as spin filter and spin-dependent beam splitter.

  2. Monte Carlo simulation of photon buildup factors for shielding materials in radiotherapy x-ray facilities

    Energy Technology Data Exchange (ETDEWEB)

    Karim Karoui, Mohamed [Faculte des Sciences de Monastir, Avenue de l' environnement 5019 Monastir -Tunisia (Tunisia); Kharrati, Hedi [Ecole Superieure des Sciences et Techniques de la Sante de Monastir, Avenue Avicenne 5000 Monastir (Tunisia)

    2013-07-15

    Purpose: This paper presents the results of a series of calculations to determine buildup factors for ordinary concrete, baryte concrete, lead, steel, and iron in broad beam geometry for photons energies from 0.125 to 25.125 MeV at 0.250 MeV intervals.Methods: Monte Carlo N-particle radiation transport computer code has been used to determine the buildup factors for the studied shielding materials.Results: The computation of the primary broad beams using buildup factors data was done for nine published megavoltage photon beam spectra ranging from 4 to 25 MV in nominal energies, representing linacs made by the three major manufacturers. The first tenth value layer and the equilibrium tenth value layer are calculated from the broad beam transmission for these nine primary megavoltage photon beam spectra.Conclusions: The results, compared with published data, show the ability of these buildup factor data to predict shielding transmission curves for the primary radiation beam. Therefore, the buildup factor data can be combined with primary, scatter, and leakage x-ray spectra to perform computation of broad beam transmission for barriers in radiotherapy shielding x-ray facilities.

  3. How robust is a thermal photon interpretation of the ALICE low-p{sub T} data?

    Energy Technology Data Exchange (ETDEWEB)

    Klasen, Michael; Koenig, Florian [Institut fuer Theoretische Physik, Westfaelische Wilhelms-Universitaet Muenster (Germany); Klein-Boesing, Christian [Institut fuer Kernphysik, Westfaelische Wilhelms-Universitaet Muenster (Germany); ExtreMe Matter Institute, GSI, Darmstadt (Germany); Wessels, Johannes [Institut fuer Kernphysik, Westfaelische Wilhelms-Universitaet Muenster (Germany)

    2014-07-01

    We present a rigorous theoretical analysis of the ALICE measurement of low-p{sub T} direct-photon production in central lead-lead collisions at the LHC with a centre-of-mass energy of √(s{sub NN}) = 2.76 TeV. Using NLO QCD, we compute the relative contributions to prompt-photon production from different initial and final states and the theoretical uncertainties coming from independent variations of the renormalisation and factorisation scales, the nuclear parton densities and the fragmentation functions. Based on different fits to the unsubtracted and prompt-photon subtracted ALICE data, we consistently find T = 304 ± 58 MeV and 309 ± 64 MeV for the effective temperature of the quark-gluon plasma (or hot medium) at p{sub T} element of [0.8;2.2] GeV and p{sub T} element of [1.5;3.5] GeV as well as a power-law (p{sub T}{sup -4}) behavior for p{sub T}>4 GeV as predicted by QCD hard scattering.

  4. How robust is a thermal photon interpretation of the ALICE low-p_T data?

    CERN Document Server

    Klasen, M; Koenig, F; Wessels, J P

    2013-01-01

    We present a rigorous theoretical analysis of the ALICE measurement of low-p_T direct-photon production in central lead-lead collisions at the LHC with a centre-of-mass energy of \\sqrt{s_{NN}}=2.76 TeV. Using NLO QCD, we compute the relative contributions to prompt-photon production from different initial and final states and the theoretical uncertainties coming from independent variations of the renormalisation and factorisation scales, the nuclear parton densities and the fragmentation functions. Based on different fits to the unsubtracted and prompt-photon subtracted ALICE data, we consistently find T = 304 \\pm 58 MeV and 309 \\pm 64 MeV for the effective temperature of the quark-gluon plasma (or hot medium) at p_T \\in [0.8;2.2] GeV and p_T \\in [1.5;3.5] GeV as well as a power-law (p_T^{-4}) behavior for p_T > 4 GeV as predicted by QCD hard scattering.

  5. How robust is a thermal photon interpretation of the ALICE low- p T data?

    Science.gov (United States)

    Klasen, M.; Klein-Bösing, C.; König, F.; Wessels, J. P.

    2013-10-01

    We present a systematic theoretical analysis of the ALICE measurement of low- p T direct-photon production in central lead-lead collisions at the LHC with a centre-of-mass-energy of TeV. Using NLO QCD, we compute the relative contributions to prompt-photon production from different initial and final states and the theoretical uncertainties coming from independent variations of the renormalisation and factorisation scales, the nuclear parton densities and the fragmentation functions. Based on different fits to the unsubtracted and prompt-photon subtracted ALICE data, we consistently find T = 304 ± 58MeV and 309 ± 64MeV for the effective temperature of the quark-gluon plasma (or hot medium) at p T ∈ [0 .8; 2 .2] GeV and p T ∈ [1 .5; 3 .5] GeV as well as a power-law () behavior for p T > 4 GeV as predicted by QCD hard scattering.

  6. Reconstruction of Photon Conversions and Precise Measurement of Photon Energy at BESⅡ%北京谱仪上光子转换过程的重建与光子能量的精确测量

    Institute of Scientific and Technical Information of China (English)

    张长春; 王喆; 袁野

    2006-01-01

    利用蒙特卡罗模拟方法,研究了光子转换过程的重建,并得到了依赖于光子能量的光子探测效率及其能量分辨的函数分布.电子的能量损失校正与光子的能量标度均用北京谱仪的真实数据做了刻度.研究表明,改进的晶体球(CB)函数能较好地描述由电子对重建出的光子能量分布.在北京谱仪实验上,对于100-260MeV能量的光子,由电子对转换方法测量的光子能量分辨可达到2.3-3.8MeV.%Using Monte Carlo simulation, reconstruction of photon conversions is studied, and the detection efficiency and energy resolution as a function of photon energy are obtained. The dE/dx correction for the electrons from photon conversions and the energy scale for the photons are calibrated with BES Ⅱ data.An improved Crystal Ball function describes well the energy distribution of the photons. Photon energy resolutions in the range from 2.3 to 3.8MeV are found for the photons with energy from 100 to 260MeV at the BES Ⅱ detector.

  7. XCOM: Photon Cross Sections Database

    Science.gov (United States)

    SRD 8 XCOM: Photon Cross Sections Database (Web, free access)   A web database is provided which can be used to calculate photon cross sections for scattering, photoelectric absorption and pair production, as well as total attenuation coefficients, for any element, compound or mixture (Z <= 100) at energies from 1 keV to 100 GeV.

  8. Photonic-crystal fibers gyroscope

    Directory of Open Access Journals (Sweden)

    Ali Muse Haider

    2015-01-01

    Full Text Available In this paper we proposed to use of a photonic crystal fiber with an inner hollow defect. The use of such fibers is not affected by a material medium on the propagation of optical radiation. Photonic crystal fibers present special properties and capabilities that lead to an outstanding potential for sensing applications

  9. Nanowire-based Quantum Photonics

    NARCIS (Netherlands)

    Bulgarini, G.

    2014-01-01

    In this thesis work, I studied individual quantum dots embedded in one-dimensional nanostructures called nanowires. Amongst the effects given by the nanometric dimensions, quantum dots enable the generation of single light particles: photons. Single photon emitters and detectors are central building

  10. Photon detection at subwavelength scales

    NARCIS (Netherlands)

    Wang, Qiang

    2015-01-01

    We first investigate the microscopic working principle of the nanowire superconducting single-photon detectors (SSPDs), and we find that the edge of the nanowire is much more sensitive than the central part. The experimental results agree quantitatively with the theory based on a photon-assisted ver

  11. Compact Photon Source Conceptual Design

    Energy Technology Data Exchange (ETDEWEB)

    Degtyarenko, Pavel V. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Wojtsekhowski, Bogdan B. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2016-04-01

    We describe options for the production of an intense photon beam at the CEBAF Hall D Tagger facility, needed for creating a high-quality secondary K 0 L delivered to the Hall D detector. The conceptual design for the Compact Photon Source apparatus is presented.

  12. Photon Production Within Storage Capsules

    CERN Document Server

    Rittmann, P D

    2003-01-01

    This report provides tables and electronic worksheets that list the photon production rate within SrF2 and CsC1 storage capsules, particularly the continuous spectrum of bremsstrahlung photons from the slowing down of the emitted electrons (BREMCALC).

  13. Complete identification of states in 208Pb below Ex=6.2 MeV

    Science.gov (United States)

    Heusler, A.; Jolos, R. V.; Faestermann, T.; Hertenberger, R.; Wirth, H.-F.; von Brentano, P.

    2016-05-01

    The Q3D magnetic spectrograph at the Maier-Leibnitz-Laboratorium of the Ludwig-Maximilians-Universität München and the Technische Universität München (Garching, Germany), was used to study the 208Pb(p ,p' ) , 206,207,208Pb (d,p), and 208Pb(d ,d' ) reactions. One hundred fifty-one states at Ex<6.20 MeV in 208Pb are identified and spin and parity assigned. Four states are newly identified and new spins and/or parities are assigned to 25 states. Tentative spin assignments are done to five states at 5.90 MeV . Nearly 50 levels below Ex=6.20 MeV listed by the Nuclear Data Sheets as of 2007 are recognized to be nonexistent or doubly placed. The schematic shell model describing one-particle-one-hole configurations without residual interaction is extended by including two-particle-two-hole configurations. The number of configurations thus predicted at Ex<6.20 MeV nearly agrees with the number of states identified. Several states with dominant two-particle-two-hole configurations are identified. New isobaric analog resonances in 209Bi with two-particle-one-hole structure are discovered at Eres=17.6 MeV . The excitation energies of 70 states with unnatural parity at Ex<6.20 MeV are found to agree within about 200 keV with one-particle-one-hole configurations predicted by the extended schematic shell model. In contrast, the excitation energies of about 20 natural parity states are more than 0.5 MeV lower than predicted, demonstrating the residual interaction among the configurations to be much larger for natural parity than for unnatural parity.

  14. Silicon photonics fundamentals and devices

    CERN Document Server

    Deen, M Jamal

    2012-01-01

    The creation of affordable high speed optical communications using standard semiconductor manufacturing technology is a principal aim of silicon photonics research. This would involve replacing copper connections with optical fibres or waveguides, and electrons with photons. With applications such as telecommunications and information processing, light detection, spectroscopy, holography and robotics, silicon photonics has the potential to revolutionise electronic-only systems. Providing an overview of the physics, technology and device operation of photonic devices using exclusively silicon and related alloys, the book includes: * Basic Properties of Silicon * Quantum Wells, Wires, Dots and Superlattices * Absorption Processes in Semiconductors * Light Emitters in Silicon * Photodetectors , Photodiodes and Phototransistors * Raman Lasers including Raman Scattering * Guided Lightwaves * Planar Waveguide Devices * Fabrication Techniques and Material Systems Silicon Photonics: Fundamentals and Devices outlines ...

  15. Quantum Simulation with Interacting Photons

    CERN Document Server

    Hartmann, Michael J

    2016-01-01

    We review the theoretical and experimental developments in recent research on quantum simulators with interacting photons. Enhancing optical nonlinearities so that they become appreciable on the single photon level and lead to nonclassical light fields has been a central objective in quantum optics for many years. After this has been achieved in individual micro-cavities representing an effectively zero-dimensional volume, this line of research has now shifted its focus towards engineering devices where such strong optical nonlinearities simultaneously occur in extended volumes of multiple nodes of a network. Recent technological progress in several experimental platforms now opens the possibility to employ the systems of strongly interacting photons these give rise to as quantum simulators. Here we review the recent development and current status of this research direction for theory and experiment. Addressing both, optical photons interacting with atoms and microwave photons in networks of superconducting c...

  16. Photonic Astronomy and Quantum Optics

    CERN Document Server

    Dravins, Dainis

    2015-01-01

    Quantum optics potentially offers an information channel from the Universe beyond the established ones of imaging and spectroscopy. All existing cameras and all spectrometers measure aspects of the first-order spatial and/or temporal coherence of light. However, light has additional degrees of freedom, manifest in the statistics of photon arrival times, or in the amount of photon orbital angular momentum. Such quantum-optical measures may carry information on how the light was created at the source, and whether it reached the observer directly or via some intermediate process. Astronomical quantum optics may help to clarify emission processes in natural laser sources and in the environments of compact objects, while high-speed photon-counting with digital signal handling enables multi-element and long-baseline versions of the intensity interferometer. Time resolutions of nanoseconds are required, as are large photon fluxes, making photonic astronomy very timely in an era of large telescopes.

  17. Surface-wave photonic quasicrystal

    CERN Document Server

    Gao, Zhen; Zhang, Youming; Xu, Hongyi; Zhang, Baile

    2016-01-01

    In developing strategies of manipulating surface electromagnetic waves, it has been recently recognized that a complete forbidden band gap can exist in a periodic surface-wave photonic crystal, which has subsequently produced various surface-wave photonic devices. However, it is not obvious whether such a concept can be extended to a non-periodic surface-wave system that lacks translational symmetry. Here we experimentally demonstrate that a surface-wave photonic quasicrystal that lacks periodicity can also exhibit a forbidden band gap for surface electromagnetic waves. The lower cutoff of this forbidden band gap is mainly determined by the maximum separation between nearest neighboring pillars. Point defects within this band gap show distinct properties compared to a periodic photonic crystal for the absence of translational symmetry. A line-defect waveguide, which is crafted out of this surface-wave photonic quasicrystal by shortening a random row of metallic rods, is also demonstrated to guide and bend sur...

  18. Silicon Nano-Photonic Devices

    DEFF Research Database (Denmark)

    Pu, Minhao

    This thesis deals with the design, fabrication and characterization of nano-photonic devices including ridge waveguide components, microring resonators, and photonic crystal components, and explore the potential for these devices in dierent applications ranging from optical communication...... is achieved with small power variation. A widely tunable microwave notch lter is also experimentally demonstrated at 40 GHz. Other application such as pulse repetition rate multiplication by using microring resonator is also presented. Photonic crystal components are studied. Two dierent types of photonic...... crystal structures are analyzed concerning index sensitivity, dispersion engineering, and slow-light coupling. Several photonic crystal devices such as index sensor, slow-light coupler, and all-optical tunable cavity are presented....

  19. A semiconductor photon-sorter

    Science.gov (United States)

    Bennett, A. J.; Lee, J. P.; Ellis, D. J. P.; Farrer, I.; Ritchie, D. A.; Shields, A. J.

    2016-10-01

    Obtaining substantial nonlinear effects at the single-photon level is a considerable challenge that holds great potential for quantum optical measurements and information processing. Of the progress that has been made in recent years one of the most promising methods is to scatter coherent light from quantum emitters, imprinting quantum correlations onto the photons. We report effective interactions between photons, controlled by a single semiconductor quantum dot that is weakly coupled to a monolithic cavity. We show that the nonlinearity of a transition modifies the counting statistics of a Poissonian beam, sorting the photons in number. This is used to create strong correlations between detection events and to create polarization-correlated photons from an uncorrelated stream using a single spin. These results pave the way for semiconductor optical switches operated by single quanta of light.

  20. Spectral compression of single photons

    CERN Document Server

    Lavoie, Jonathan; Wright, Logan G; Fedrizzi, Alessandro; Resch, Kevin J

    2013-01-01

    Photons are critical to quantum technologies since they can be used for virtually all quantum information tasks: in quantum metrology, as the information carrier in photonic quantum computation, as a mediator in hybrid systems, and to establish long distance networks. The physical characteristics of photons in these applications differ drastically; spectral bandwidths span 12 orders of magnitude from 50 THz for quantum-optical coherence tomography to 50 Hz for certain quantum memories. Combining these technologies requires coherent interfaces that reversibly map centre frequencies and bandwidths of photons to avoid excessive loss. Here we demonstrate bandwidth compression of single photons by a factor 40 and tunability over a range 70 times that bandwidth via sum-frequency generation with chirped laser pulses. This constitutes a time-to-frequency interface for light capable of converting time-bin to colour entanglement and enables ultrafast timing measurements. It is a step toward arbitrary waveform generatio...

  1. Photonic nanowires for quantum optics

    DEFF Research Database (Denmark)

    Munsch, M.; Claudon, J.; Bleuse, J.;

    Photonic nanowires (PWs) are simple dielectric structures for which a very efficient and broadband spontaneous emission (SE) control has been predicted [1]. Recently, a single photon source featuring a record high efficiency was demonstrated using this geometry [2]. Using time-resolved micro......-photoluminescence, we investigate directly the SE of single InAs quantum dots (QDs) embedded in GaAs PWs and demonstrate performances that fully confirm the theoretical predictions [3]. In addition, we discuss recent results obtained on elliptical wires that ensure an efficient control of the photon polarization [4......, equivalent to the one obtained in state-of-the-art 2D photonic crystals, is measured. Moreover, a PW featuring an elliptical section provides a very efficient control over the polarization of the emitted photon. In that case, only one guided mode, with a linear polarization oriented along the major axis...

  2. Modelling of photonic crystal fibres

    DEFF Research Database (Denmark)

    Knudsen, Erik

    2003-01-01

    In the presenta ph.d. work a theoretical study of aspects of modelling photonic crystal fibres was carried out. Photonic crystal fibres form a class of optical waveguides where guidance is no longer provided by a difference in refractive index between core and cladding. Instead, guidance...... is provided by an arrangement of air-holes running along the length of the fibre. Depending on the geometry of the fibre, the guiding mechanism may be either arising from the formation of a photonic bandgap in the cladding structure (photonic bandgap fibre), or by an effect resembling total internal...... modes in contiguous fibre segments curved at different radii. Overall microbend loss is expressed as a statistical mean of mismatch losses. Extending a well proven, established formula for macrobending losses in stop index fibres, we provide an estimate of macrobend losses in an air-guiding photonic...

  3. Electron pair creation by photons

    NARCIS (Netherlands)

    Holtwijk, Theodoor

    1960-01-01

    In our experiment on the creation of electron pairs a 5 MeV betatron was used as radiation source and a cloud chamber (with magnetic field) was used as detection instrument. The experimental arrangement is described in section 2.1. The cloud chamber was of the overcompression type so that the recove

  4. Photonic quantum information: science and technology.

    Science.gov (United States)

    Takeuchi, Shigeki

    2016-01-01

    Recent technological progress in the generation, manipulation and detection of individual single photons has opened a new scientific field of photonic quantum information. This progress includes the realization of single photon switches, photonic quantum circuits with specific functions, and the application of novel photonic states to novel optical metrology beyond the limits of standard optics. In this review article, the recent developments and current status of photonic quantum information technology are overviewed based on the author's past and recent works.

  5. Spatial photon correlations in multiple scattering media

    DEFF Research Database (Denmark)

    Smolka, Stephan; Muskens, O.; Lagendijk, A.;

    2010-01-01

    We present the first angle-resolved measurements of spatial photon correlations that are induced by multiple scattering of light. The correlation relates multiple scattered photons at different spatial positions and depends on incident photon fluctuations.......We present the first angle-resolved measurements of spatial photon correlations that are induced by multiple scattering of light. The correlation relates multiple scattered photons at different spatial positions and depends on incident photon fluctuations....

  6. Neutron-induced fission cross sections of 242Pu from 0.3 MeV to 3 MeV

    Science.gov (United States)

    Salvador-Castiñeira, P.; Bryś, T.; Eykens, R.; Hambsch, F.-J.; Göök, A.; Moens, A.; Oberstedt, S.; Sibbens, G.; Vanleeuw, D.; Vidali, M.; Pretel, C.

    2015-10-01

    The majority of the next generation of nuclear power plants (GEN-IV) will work in the fast-neutron-energy region, as opposed to present day thermal reactors. This leads to new and more accurate nuclear-data needs for some minor actinides and structural materials. Following those upcoming demands, the Organisation for Economic Cooperation and Development Nuclear Energy Agency performed a sensitivity study. Based on the latter, an improvement in accuracy from the present 20% to 5% is required for the 242Pu(n ,f ) cross section. Within the same project both the 240Pu(n ,f ) cross section and the 242Pu(n ,f ) cross section were measured at the Van de Graaff accelerator of the Joint Research Centre at the Institute for Reference Materials and Measurements, where quasimonoenergetic neutrons were produced in an energy range from 0.3 MeV up to 3 MeV. A twin Frisch-grid ionization chamber has been used in a back-to-back configuration as fission-fragment detector. The 242Pu(n ,f ) cross section has been normalized to three different isotopes: 237Np(n ,f ) , 235U(n ,f ) , and 238U(n ,f ) . A comprehensive study of the corrections applied to the data and the uncertainties associated is given. The results obtained are in agreement with previous experimental data at the threshold region up to 0.8 MeV. The resonance-like structure at 0.8 to 1.1 MeV, visible in the evaluations and in most previous experimental values, was not reproduced with the same intensity in this experiment. For neutron energies higher than 1.1 MeV, the results of this experiment are slightly lower than the Evaluated Nuclear Data File/B-VII.1 evaluation but in agreement with the experiment of Tovesson et al. (2009) as well as Staples and Morley (1998). Finally, for energies above 1.5 MeV, the results show consistency with the present evaluations.

  7. Regenerative photonic therapy: Review

    Science.gov (United States)

    Salansky, Natasha; Salansky, Norman

    2012-09-01

    After four decades of research of photobiomodulation phenomena in mammals in vitro and in vivo, a solid foundation is created for the use of photobiomodulation in regenerative medicine. Significant accomplishments are achieved in animal models that demonstrate opportunities for photo-regeneration of injured or pathological tissues: skin, muscles and nerves. However, the use of photobiomodulation in clinical studies leads to controversial results while negative or marginal clinical efficacy is reported along with positive findings. A thor ough analysis of requirements to the optical parameters (dosimetry) for high efficacy in photobimodulation led us to the conclusion that there are several misconceptions in the clinical applications of low level laser therapy (LLLT). We present a novel appr oach of regenerative photonic therapy (RPT) for tissue healing and regeneration that overcomes major drawbacks of LLLT. Encouraging clinical results on RPT efficacy are presented. Requirements for RPT approach and vision for its future development for tissue regeneration is discussed.

  8. Photonic Floquet Topological Insulators

    CERN Document Server

    Rechtsman, Mikael C; Plotnik, Yonatan; Lumer, Yaakov; Nolte, Stefan; Segev, Mordechai; Szameit, Alexander

    2012-01-01

    The topological insulator is a fundamentally new phase of matter, with the striking property that the conduction of electrons occurs only on its surface, not within the bulk, and that conduction is topologically protected. Topological protection, the total lack of scattering of electron waves by disorder, is perhaps the most fascinating and technologically important aspect of this material: it provides robustness that is otherwise known only for superconductors. However, unlike superconductivity and the quantum Hall effect, which necessitate low temperatures or magnetic fields, the immunity to disorder of topological insulators occurs at room temperature and without any external magnetic field. For this reason, topological protection is predicted to have wide-ranging applications in fault-tolerant quantum computing and spintronics. Recently, a large theoretical effort has been directed towards bringing the concept into the domain of photonics: achieving topological protection of light at optical frequencies. ...

  9. Photonics a short course

    CERN Document Server

    Degiorgio, Vittorio

    2014-01-01

    This book will serve as a concise, self-contained, up-to-date introduction to Photonics, to be used as a textbook for undergraduate students or as a reference book for researchers and professionals. Blending theory with technical descriptions, the book covers a wide range of topics, including the general mechanism of laser action, continuous and pulsed laser operation, optical propagation in isotropic and anisotropic media, operating principles and structure of passive optical components, electro-optical and acousto-optical modulation, solid-state lasers, semiconductor lasers and LEDs, nonlinear optics, and optical fiber components and devices.. The book concludes with an overview of applications, including optical communications, telemetry and sensing, industrial and biomedical applications, solid-state lighting, displays, and photovoltaics.

  10. Perovskite photonic sources

    Science.gov (United States)

    Sutherland, Brandon R.; Sargent, Edward H.

    2016-05-01

    The field of solution-processed semiconductors has made great strides; however, it has yet to enable electrically driven lasers. To achieve this goal, improved materials are required that combine efficient (>50% quantum yield) radiative recombination under high injection, large and balanced charge-carrier mobilities in excess of 10 cm2 V-1 s-1, free-carrier densities greater than 1017 cm-3 and gain coefficients exceeding 104 cm-1. Solid-state perovskites are -- in addition to galvanizing the field of solar electricity -- showing great promise in photonic sources, and may be the answer to realizing solution-cast laser diodes. Here, we discuss the properties of perovskites that benefit light emission, review recent progress in perovskite electroluminescent diodes and optically pumped lasers, and examine the remaining challenges in achieving continuous-wave and electrically driven lasing.

  11. Photonics a short course

    CERN Document Server

    Degiorgio, Vittorio

    2016-01-01

    This extended and revised edition will serve as a concise, self-contained, up-to-date introduction to Photonics for undergraduate students. It can also be used as a primer by researchers and professionals who start working in the field. Blending theory with technical descriptions, the book covers a wide range of topics, including the general mechanism of laser action, continuous and pulsed laser operation, optical propagation in isotropic and anisotropic media, operating principles and structure of passive optical components, electro-optic and acousto-optic modulation, solid-state lasers, semiconductor lasers and LEDs, nonlinear optical phenomena, and optical fiber components and devices. The book concludes with an overview of applications, including optical communications, telemetry and sensing, industrial and biomedical applications, solid-state lighting, displays, and photovoltaics. This second edition includes a set of problems at the end of all but the last chapter. These problems deal with numerical c...

  12. Photon counting digital holography

    Science.gov (United States)

    Demoli, Nazif; Skenderović, Hrvoje; Stipčević, Mario; Pavičić, Mladen

    2016-05-01

    Digital holography uses electronic sensors for hologram recording and numerical method for hologram reconstruction enabling thus the development of advanced holography applications. However, in some cases, the useful information is concealed in a very wide dynamic range of illumination intensities and successful recording requires an appropriate dynamic range of the sensor. An effective solution to this problem is the use of a photon-counting detector. Such detectors possess counting rates of the order of tens to hundreds of millions counts per second, but conditions of recording holograms have to be investigated in greater detail. Here, we summarize our main findings on this problem. First, conditions for optimum recording of digital holograms for detecting a signal significantly below detector's noise are analyzed in terms of the most important holographic measures. Second, for time-averaged digital holograms, optimum recordings were investigated for exposures shorter than the vibration cycle. In both cases, these conditions are studied by simulations and experiments.

  13. Progress on photonic crystals

    CERN Document Server

    Lecoq, P; Gundacker, S; Hillemanns, H; Jarron, P; Knapitsch, A; Leclercq, J L; Letartre, X; Meyer, T; Pauwels, K; Powolny, F; Seassal, C

    2010-01-01

    The renewal of interest for Time of Flight Positron Emission Tomography (TOF PET) has highlighted the need for increasing the light output of scintillating crystals and in particular for improving the light extraction from materials with a high index of refraction. One possible solution to overcome the problem of total internal reflection and light losses resulting from multiple bouncing within the crystal is to improve the light extraction efficiency at the crystal/photodetector interface by means of photonic crystals, i.e. media with a periodic modulation of the dielectric constant at the wavelength scale. After a short reminder of the underlying principles this contribution proposes to present the very encouraging results we have recently obtained on LYSO pixels and the perspectives on other crystals such as BGO, LuYAP and LuAG. These results confirm the impressive predictions from our previously published Monte Carlo simulations. A detailed description of the sample preparation procedure is given as well ...

  14. Photon technology. Laser processing technology; Photon technology. Laser process gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    Survey has been conducted to develop laser processing technology utilizing the interaction between substance and photon. This is a part of the leading research on photon technology development. The photon technology development is aimed at novel technology development highly utilizing the quantum nature of photons. In the field of laser processing, high quality photons are used as tools, special functions of atoms and molecules will be discovered, and processing for functional fabrication (photon machining) will be established. A role of laser processing in industries has become significant, which is currently spreading not only into cutting and welding of materials and scalpels but also into such a special field as ultrafine processing of materials. The spreading is sometimes obstructed due to the difficulty of procurement of suitable machines and materials, and the increase of cost. The purpose of this study is to develop the optimal laser technology, to elucidate the interaction between substance and photon, and to develop the laser system and the transmission and regulation systems which realize the optimal conditions. 387 refs., 115 figs., 25 tabs.

  15. Photon-efficient imaging with a single-photon camera

    Science.gov (United States)

    Shin, Dongeek; Xu, Feihu; Venkatraman, Dheera; Lussana, Rudi; Villa, Federica; Zappa, Franco; Goyal, Vivek K.; Wong, Franco N. C.; Shapiro, Jeffrey H.

    2016-06-01

    Reconstructing a scene's 3D structure and reflectivity accurately with an active imaging system operating in low-light-level conditions has wide-ranging applications, spanning biological imaging to remote sensing. Here we propose and experimentally demonstrate a depth and reflectivity imaging system with a single-photon camera that generates high-quality images from ~1 detected signal photon per pixel. Previous achievements of similar photon efficiency have been with conventional raster-scanning data collection using single-pixel photon counters capable of ~10-ps time tagging. In contrast, our camera's detector array requires highly parallelized time-to-digital conversions with photon time-tagging accuracy limited to ~ns. Thus, we develop an array-specific algorithm that converts coarsely time-binned photon detections to highly accurate scene depth and reflectivity by exploiting both the transverse smoothness and longitudinal sparsity of natural scenes. By overcoming the coarse time resolution of the array, our framework uniquely achieves high photon efficiency in a relatively short acquisition time.

  16. Nonlocal hyperconcentration on entangled photons using photonic module system

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Cong; Wang, Tie-Jun; Mi, Si-Chen [School of Science, Beijing University of Posts and Telecommunications, Beijing 100876 (China); State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing 100876 (China); Zhang, Ru [School of Science, Beijing University of Posts and Telecommunications, Beijing 100876 (China); State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing 100876 (China); School of Ethnic Minority Education, Beijing University of Posts and Telecommunications, Beijing 100876 (China); Wang, Chuan, E-mail: wangchuan@bupt.edu.cn [School of Science, Beijing University of Posts and Telecommunications, Beijing 100876 (China); State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing 100876 (China)

    2016-06-15

    Entanglement distribution will inevitably be affected by the channel and environment noise. Thus distillation of maximal entanglement nonlocally becomes a crucial goal in quantum information. Here we illustrate that maximal hyperentanglement on nonlocal photons could be distilled using the photonic module and cavity quantum electrodynamics, where the photons are simultaneously entangled in polarization and spatial-mode degrees of freedom. The construction of the photonic module in a photonic band-gap structure is presented, and the operation of the module is utilized to implement the photonic nondestructive parity checks on the two degrees of freedom. We first propose a hyperconcentration protocol using two identical partially hyperentangled initial states with unknown coefficients to distill a maximally hyperentangled state probabilistically, and further propose a protocol by the assistance of an ancillary single photon prepared according to the known coefficients of the initial state. In the two protocols, the total success probability can be improved greatly by introducing the iteration mechanism, and only one of the remote parties is required to perform the parity checks in each round of iteration. Estimates on the system requirements and recent experimental results indicate that our proposal is realizable with existing or near-further technologies.

  17. Dark Sunshine: Detecting Dark Matter through Dark Photons from the Sun

    CERN Document Server

    Feng, Jonathan L; Tanedo, Philip

    2016-01-01

    Dark matter may interact with the Standard Model through the kinetic mixing of dark photons, $A'$, with Standard Model photons. Such dark matter will accumulate in the Sun and annihilate into dark photons. The dark photons may then leave the Sun and decay into pairs of charged Standard Model particles that can be detected by the Alpha Magnetic Spectrometer. The directionality of this "dark sunshine" is distinct from all astrophysical backgrounds, providing an opportunity for unambiguous dark matter discovery by AMS. We perform a complete analysis of this scenario including Sommerfeld enhancements of dark matter annihilation and the effect of the Sun's magnetic field on the signal, and we define a set of cuts to optimize the signal probability. With the three years of data already collected, AMS may discover dark matter with mass 1 TeV $\\lesssim m_X \\lesssim$ 10 TeV, dark photon masses $m_{A'} \\sim \\mathcal O(100)$ MeV, and kinetic mixing parameters $10^{-11} \\lesssim \\varepsilon \\lesssim 10^{-8}$. The propose...

  18. Non-Equilibrium Production of Photons via $\\pi^0 \\to 2\\gamma$ in DCCs

    CERN Document Server

    Boyanovsky, D; Holman, R; Kumar, S P

    1997-01-01

    We study production of photons via the non-equilibrium relaxation of a Disoriented Chiral Condensate with the chiral order parameter having a large initial amplitude along the \\pi^0 direction. Assuming the validity of the low energy coupling of the neutral pion to photons via the U_A(1) anomalous vertex, we find that for large initial amplitudes along the \\pi^0 direction, photon production is enhanced by parametric amplification. These processes are non-perturbative with a large contribution during the non-equilibrium stages of the evolution and result in a distinct distribution of the produced photons and a polarization asymmetry. For initial amplitudes of the \\pi^0 component of the order parameter between 200-400 MeV, corresponding to energy densities between 1-12 GeV/fm^3 we find a peak in the photon distribution at energies between 5-10%. We discuss the potential experimental impact of these results as well as the problems associated with its detection.

  19. Dark Photons from the Center of the Earth: Smoking-Gun Signals of Dark Matter

    CERN Document Server

    Feng, Jonathan L; Tanedo, Philip

    2015-01-01

    Dark matter may be charged under dark electromagnetism with a dark photon that kinetically mixes with the Standard Model photon. In this framework, dark matter will collect at the center of the Earth and annihilate into dark photons, which may reach the surface of the Earth and decay into observable particles. We determine the resulting signal rates, including Sommerfeld enhancements, which play an important role in bringing the Earth's dark matter population to their maximal, equilibrium value. For dark matter masses $m_X \\sim$ 100 GeV - 10 TeV, dark photon masses $m_{A'} \\sim$ MeV - GeV, and kinetic mixing parameters $\\varepsilon \\sim 10^{-9} - 10^{-7}$, the resulting electrons, muons, photons, and hadrons that point back to the center of the Earth are a smoking-gun signal of dark matter that may be detected by a variety of experiments, including neutrino telescopes, such as IceCube, and space-based cosmic ray detectors, such as Fermi-LAT and AMS. We determine the signal rates and characteristics, and show ...

  20. Highly Stripped Ion Sources for MeV Ion Implantation

    Energy Technology Data Exchange (ETDEWEB)

    Hershcovitch, Ady

    2009-06-30

    Original technical objectives of CRADA number PVI C-03-09 between BNL and Poole Ventura, Inc. (PVI) were to develop an intense, high charge state, ion source for MeV ion implanters. Present day high-energy ion implanters utilize low charge state (usually single charge) ion sources in combination with rf accelerators. Usually, a MV LINAC is used for acceleration of a few rnA. It is desirable to have instead an intense, high charge state ion source on a relatively low energy platform (de acceleration) to generate high-energy ion beams for implantation. This de acceleration of ions will be far more efficient (in energy utilization). The resultant implanter will be smaller in size. It will generate higher quality ion beams (with lower emittance) for fabrication of superior semiconductor products. In addition to energy and cost savings, the implanter will operate at a lower level of health risks associated with ion implantation. An additional aim of the project was to producing a product that can lead to long­ term job creation in Russia and/or in the US. R&D was conducted in two Russian Centers (one in Tomsk and Seversk, the other in Moscow) under the guidance ofPVI personnel and the BNL PI. Multiple approaches were pursued, developed, and tested at various locations with the best candidate for commercialization delivered and tested at on an implanter at the PVI client Axcelis. Technical developments were exciting: record output currents of high charge state phosphorus and antimony were achieved; a Calutron-Bemas ion source with a 70% output of boron ion current (compared to 25% in present state-of-the-art). Record steady state output currents of higher charge state phosphorous and antimony and P ions: P{sup 2+} (8.6 pmA), P{sup 3+} (1.9 pmA), and P{sup 4+} (0.12 pmA) and 16.2, 7.6, 3.3, and 2.2 pmA of Sb{sup 3+} Sb {sup 4 +}, Sb{sup 5+}, and Sb{sup 6+} respectively. Ultimate commercialization goals did not succeed (even though a number of the products like high

  1. Holographic Two-Photon Induced Photopolymerization

    Data.gov (United States)

    Federal Laboratory Consortium — Holographic two-photon-induced photopolymerization (HTPIP) offers distinct advantages over conventional one-photon-induced photopolymerization and current techniques...

  2. Monte Carlo simulations and benchmark measurements on the response of TE(TE) and Mg(Ar) ionization chambers in photon, electron and neutron beams

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Yi-Chun [Health Physics Division, Institute of Nuclear Energy Research, Taoyuan County, Taiwan (China); Huang, Tseng-Te, E-mail: huangtt@iner.gov.tw [Health Physics Division, Institute of Nuclear Energy Research, Taoyuan County, Taiwan (China); Liu, Yuan-Hao [Nuclear Science and Technology Development Center, National Tsing Hua University, Hsinchu City, Taiwan (China); Chen, Wei-Lin [Institute of Nuclear Engineering and Science, National Tsing Hua University, Hsinchu City, Taiwan (China); Chen, Yen-Fu [Atomic Energy Council, New Taipei City, Taiwan (China); Wu, Shu-Wei [Dept. of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan (China); Nievaart, Sander [Institute for Energy, Joint Research Centre, European Commission, Petten (Netherlands); Jiang, Shiang-Huei [Dept. of Engineering and System Science, National Tsing Hua University, Hsinchu, Taiwan (China)

    2015-06-01

    The paired ionization chambers (ICs) technique is commonly employed to determine neutron and photon doses in radiology or radiotherapy neutron beams, where neutron dose shows very strong dependence on the accuracy of accompanying high energy photon dose. During the dose derivation, it is an important issue to evaluate the photon and electron response functions of two commercially available ionization chambers, denoted as TE(TE) and Mg(Ar), used in our reactor based epithermal neutron beam. Nowadays, most perturbation corrections for accurate dose determination and many treatment planning systems are based on the Monte Carlo technique. We used general purposed Monte Carlo codes, MCNP5, EGSnrc, FLUKA or GEANT4 for benchmark verifications among them and carefully measured values for a precise estimation of chamber current from absorbed dose rate of cavity gas. Also, energy dependent response functions of two chambers were calculated in a parallel beam with mono-energies from 20 keV to 20 MeV photons and electrons by using the optimal simple spherical and detailed IC models. The measurements were performed in the well-defined (a) four primary M-80, M-100, M120 and M150 X-ray calibration fields, (b) primary {sup 60}Co calibration beam, (c) 6 MV and 10 MV photon, (d) 6 MeV and 18 MeV electron LINACs in hospital and (e) BNCT clinical trials neutron beam. For the TE(TE) chamber, all codes were almost identical over the whole photon energy range. In the Mg(Ar) chamber, MCNP5 showed lower response than other codes for photon energy region below 0.1 MeV and presented similar response above 0.2 MeV (agreed within 5% in the simple spherical model). With the increase of electron energy, the response difference between MCNP5 and other codes became larger in both chambers. Compared with the measured currents, MCNP5 had the difference from the measurement data within 5% for the {sup 60}Co, 6 MV, 10 MV, 6 MeV and 18 MeV LINACs beams. But for the Mg(Ar) chamber, the derivations

  3. Elastic Neutron Scattering at 96 MeV from {sup 12}C and {sup 208}Pb

    Energy Technology Data Exchange (ETDEWEB)

    Klug, J.; Blomgren, J.; Atac, A. [and others

    2003-04-01

    A facility for detection of scattered neutrons in the energy interval 50-130 MeV, SCANDAL (SCAttered Nucleon Detection AssembLy), has recently been installed at the 20-180 MeV neutron beam line of the The Svedberg Laboratory, Uppsala. Elastic neutron scattering from {sup 12}C and {sup 208}Pb has been studied at 96 MeV in the 10-70 deg interval. The achieved energy resolution, 3.7 MeV, is about an order of magnitude better than for any previous experiment above 65 MeV incident energy. The present experiment represents the highest neutron energy where the ground state has been resolved from the first excited state in neutron scattering. A novel method for normalization of the absolute scale of the cross section has been used. The estimated uncertainty, 3 %, is unprecedented for a neutron-induced differential cross section measurement on a nuclear target. The results are compared with modern optical model predictions, based on phenomenology or microscopic nuclear theory.

  4. Damage kinetics in MeV gold ion - Irradiated crystalline quartz

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, S.M.M. E-mail: ramos@dpm.univ-lyon1.fr; Clerc, C.; Canut, B.; Chaumont, J.; Toulemonde, M.; Bernas, H

    2000-05-02

    Damage creation in crystalline {alpha}-quartz under gold irradiation was studied at 1.0 and 5.5 MeV using the ARAMIS accelerator at CSNSM (Orsay). Although at these energies the total stopping powers are nearly equal (respectively, 4.20 and 4.46 keV nm{sup -1}), the electronic stopping power is only 1.23 keV nm{sup -1} (25% of the total) at 1 MeV while it reaches 2.75 keV nm{sup -1} (62% of the total) at 5.5 MeV. The electronic stopping power threshold for damage creation in {alpha}-quartz is about 1.8 keV/nm . The experiment thus allows us to follow the damage production kinetics due to nuclear collisions (at 1 MeV) versus electronic collisions (at 5.5 MeV). The damage was determined by channeling Rutherford backscattering (RBS-C) using the 2 MV Van de Graaff at DPM (Villeurbanne). Single ion impacts create damage when electronic stopping dominates, while several impacts are necessary to achieve complete damage when nuclear stopping dominates. Differences in damage efficiencies will be discussed.

  5. Modification of semiconductor or metal nanoparticle lattices in amorphous alumina by MeV heavy ions

    Science.gov (United States)

    Bogdanović Radović, I.; Buljan, M.; Karlušić, M.; Jerčinović, M.; Dražič, G.; Bernstorff, S.; Boettger, R.

    2016-09-01

    In the present work we investigate effects of MeV heavy ions (from 0.4 MeV Xe to 15 MeV Si) on regularly ordered nanoparticle (NP) lattices embedded in amorphous alumina matrix. These nanostructures were produced by self-assembling growth using magnetron-sputtering deposition. From grazing incidence small-angle x-ray scattering measurements we have found that the used MeV heavy ions do not change the NP sizes, shapes or distances among them. However, ions cause a tilt of the entire NP lattice in the direction parallel to the surface. The tilt angle depends on the incident ion energy, type and the applied fluence and a nearly linear increase of the tilt angle with the ion fluence and irradiation angle was found. This way, MeV heavy ion irradiation can be used to design custom-made NP lattices. In addition, grazing incidence small-angle x-ray scattering can be effectively used as a method for the determination of material redistribution/shift caused by the ion hammering effect. For the first time, the deformation yield in amorphous alumina was determined for irradiation performed at the room temperature.

  6. Higher-order photon correlations in pulsed photonic crystal nanolasers

    CERN Document Server

    Elvira, David; Verma, V; Braive, Remy; Beaudoin, Gregoire; Robert-Philip, Isabelle; Sagnes, Isabelle; Baek, Burm; Nam, Sae Woo; Dauler, Eric A; Abram, Izo; Stevens, Martin J; Beveratos, Alexios

    2011-01-01

    We report on the higher-order photon correlations of a high-$\\beta$ nanolaser under pulsed excitation at room temperature. Using a multiplexed four-element superconducting single photon detector we measured g$^{(n)}(\\vec{0})$ with $n$=2,3,4. All orders of correlation display partially chaotic statistics, even at four times the threshold excitation power. We show that this departure from coherence and Poisson statistics is due to the quantum fluctuations associated with the small number of dipoles and photons involved in the lasing process.

  7. Independent isotopic yields in 25 MeV and 50 MeV proton-induced fission of {sup nat}U

    Energy Technology Data Exchange (ETDEWEB)

    Penttilae, H.; Gorelov, D.; Elomaa, V.V.; Eronen, T.; Hager, U.; Hakala, J.; Jokinen, A.; Kankainen, A.; Karvonen, P.; Moore, I.D.; Parkkonen, J.; Pohjalainen, I.; Rahaman, S.; Rinta-Antila, S.; Rissanen, J.; Saastamoinen, A.; Simutkin, V.; Sonoda, T.; Weber, C.; Voss, A.; Aeystoe, J. [Department of Physics, University of Jyvaskylae (Finland); Peraejaervi, K. [STUK - Radiation and Nuclear Safety Authority, Helsinki (Finland); Rubchenya, V.A. [Department of Physics, University of Jyvaskylae (Finland); V.G. Khlopin Radium Institute, St. Petersburg (Russian Federation)

    2016-04-15

    Independent isotopic yields for elements from Zn to La in the 25 MeV proton-induced fission of {sup nat}U were determined with the JYFLTRAP facility. In addition, isotopic yields for Zn, Ga, Rb, Sr, Zr, Pd and Xe in the 50 MeV proton-induced fission of {sup nat}U were measured. The deduced isotopic yield distributions are compared with a Rubchenya model, the GEF model with universal parameters and the semi-empirical Wahl model. Of these, the Rubchenya model gives the best overall agreement with the obtained data. Combining the isotopic yield data with mass yield data to obtain the absolute independent yields was attempted. The result depends on the mass yield distribution. (orig.)

  8. Monte Carlo calculations of efficiencies for photon interactions in plastic scintillators

    Energy Technology Data Exchange (ETDEWEB)

    Bonzi, E.V.; Mainardi, R.T. (Facultad de Matematica, Astronomia y Fisica, Univ. Nacional de Cordoba (Argentina))

    1992-12-01

    Energy absorption and total peak efficiencies for plastic scintillators have been calculated by means of the Monte Carlo method. These results are of interest for potential uses of plastic scintillators as dosimetric or spectrometric devices. The calculations were carried out for photon energies from 2 keV up to 1 MeV. We considered all of the physical effects involved in each range of energy, photoelectric, Compton and Rayleigh. As a consistency test the same code was used to calculate efficiencies for NaI scintillators. The agreement with results published previously by other authors, within calculated errors, is very satisfactory. (orig.).

  9. Measurement of Ultra-Short Single-Photon Pulse Duration with Two-Photon Interference

    Institute of Scientific and Technical Information of China (English)

    LV Fan; SUN Fang-Wen; ZOU Chang-Ling; HAN Zheng-Fu; GUO Guang-Can

    2011-01-01

    We proposed a protocol of measuring the duration of ultra-short single-photon pulse with two-photon interference.The pulse duration can be obtained from the width of the visibility of two-photon Hong-Ou-Mandel interference or the indistinguishability of the two photons. Moreover, the shape of a single-photon pulse can be measured with ultra-short single-photon pulses through the two-photon interference.%@@ We proposed a protocol of measuring the duration of ultra-short single-photon pulse with two-photon interference.The pulse duration can be obtained from the width of the visibility of two-photon Hong-Ou-Mandel interference or the indistinguishability of the two photons.Moreover, the shape of a single-photon pulse can be measured with ultra-short single-photon pulses through the two-photon interference.

  10. Digital neutron/gamma discrimination with an organic scintillator at energies between 1 MeV and 100 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Comrie, A.C. [Department of Physics, University of Cape Town, Rondebosch 7700 (South Africa); Buffler, A., E-mail: andy.buffler@uct.ac.za [Department of Physics, University of Cape Town, Rondebosch 7700 (South Africa); Smit, F.D. [iThemba LABS, Somerset West 7129 (South Africa); Wörtche, H.J. [INCAS" 3, Dr. Nassaulaan 9. 9400 AT Assen (Netherlands)

    2015-02-01

    Three different digital implementations of pulse shape discrimination for pulses from an EJ301 liquid scintillator detector are presented, and illustrated with neutrons and gamma-rays produced by an Am–Be radioisotopic source, a D–T generator and beams produced by cyclotron-accelerated protons of energies 42, 62 and 100 MeV on a Li target. A critical comparison between the three methods is provided.

  11. Photonic Landau levels on cones

    Science.gov (United States)

    Schine, Nathan; Ryou, Albert; Gromov, Andrey; Sommer, Ariel; Simon, Jonathan

    2016-05-01

    We present the first experimental realization of a bulk magnetic field for optical photons. By using a non-planar ring resonator, we induce an image rotation on each round trip through the resonator. This results in a Coriolis/Lorentz force and a centrifugal anticonfining force, the latter of which is cancelled by mirror curvature. Using a digital micromirror device to control both amplitude and phase, we inject arbitrary optical modes into our resonator. Spatial- and energy- resolved spectroscopy tracks photonic eigenstates as residual trapping is reduced, and we observe photonic Landau levels as the eigenstates become degenerate. We show that there is a conical geometry of the resulting manifold for photon dynamics and present a measurement of the local density of states that is consistent with Landau levels on a cone. While our work already demonstrates an integer quantum Hall material composed of photons, we have ensured compatibility with strong photon-photon interactions, which will allow quantum optical studies of entanglement and correlation in manybody systems including fractional quantum Hall fluids.

  12. Photonic crystal enhanced cytokine immunoassay.

    Science.gov (United States)

    Mathias, Patrick C; Ganesh, Nikhil; Cunningham, Brian T

    2009-01-01

    Photonic crystal surfaces are demonstrated as a means for enhancing the detection sensitivity and resolution for assays that use a fluorescent tag to quantify the concentration of an analyte protein molecule in a liquid test sample. Computer modeling of the spatial distribution of resonantly coupled electromagnetic fields on the photonic crystal surface are used to estimate the magnitude of enhancement factor compared to performing the same fluorescent assay on a plain glass surface, and the photonic crystal structure is fabricated and tested to experimentally verify the performance using a sandwich immunoassay for the protein Tumor Necrosis Factor-alpha (TNF-alpha). The demonstrated photonic crystal fabrication method utilizes a nanoreplica molding technique that allows for large-area inexpensive fabrication of the structure in a format that is compatible with confocal microarray laser scanners. The signal-to-noise ratio for fluorescent spots on the photonic crystal is increased by at least five-fold relative to the glass slide, allowing a TNF-alpha concentration of 1.6 pg/ml to be distinguished from noise on a photonic crystal surface. In addition, the minimum quantitative limit of detection on the photonic crystal surface is one-third the limit on the glass slide - a decrease from 18 pg/ml to 6 pg/ml. The increased performance of the immunoassay allows for more accurate quantitation of physiologically relevant concentrations of TNF-alpha in a protein microarray format that can be expanded to multiple cytokines.

  13. ITMO Photonics: center of excellence

    Science.gov (United States)

    Voznesenskaya, Anna; Bougrov, Vladislav; Kozlov, Sergey; Vasilev, Vladimir

    2016-09-01

    ITMO University, the leading Russian center in photonics research and education, has the mission to train highlyqualified competitive professionals able to act in conditions of fast-changing world. This paradigm is implemented through creation of a strategic academic unit ITMO Photonics, the center of excellence concentrating organizational, scientific, educational, financial, laboratory and human resources. This Center has the following features: dissemination of breakthrough scientific results in photonics such as advanced photonic materials, ultrafast optical and quantum information, laser physics, engineering and technologies, into undergraduate and graduate educational programs through including special modules into the curricula and considerable student's research and internships; transformation of the educational process in accordance with the best international educational practices, presence in the global education market in the form of joint educational programs with leading universities, i.e. those being included in the network programs of international scientific cooperation, and international accreditation of educational programs; development of mechanisms for the commercialization of innovative products - results of scientific research; securing financial sustainability of research in the field of photonics of informationcommunication systems via funding increase and the diversification of funding sources. Along with focusing on the research promotion, the Center is involved in science popularization through such projects as career guidance for high school students; interaction between student's chapters of international optical societies; invited lectures of World-famous experts in photonics; short educational programs in optics, photonics and light engineering for international students; contests, Olympics and grants for talented young researchers; social events; interactive demonstrations.

  14. A high-brightness, electron-based source of polarized photons and neutrons

    Science.gov (United States)

    Spencer, J. E.

    1999-06-01

    A compact and comparatively inexpensive system that is practical for universities is described based on a low-energy, electron storage ring with at least one undulator based oscillator to store photons. If the oscillator cavity length is relativistically corrected to be an harmonic of the ring circumference (LC=βLRn/nB with nB the number of bunches), higher-energy, secondary photons from Compton backscattering may become significant. Then, besides synchrotron radiation from the ring dipoles and damping wigglers as well as undulator photons, there are frequency upshifted Compton photons and photoneutrons from low Q-value targets such as Beryllium (Qn=-1.66) or Deuterium (Qn=-2.22 MeV). For 100 MeV electron bunches, an adjustable-phase, planar, helical undulator can be made to produce circularly polarized UV photons having a fundamental ɛγ1=11.1 eV. If these photons are stored in a multimode, hole-coupled resonator they produce a Compton endpoint energy up to ɛγ2=1.7 MeV. When incident on a Be conversion target these secondary photons make unmoderated, epithermal neutrons having mean energy ɛn=24.8±6.8 keV from the two-body reaction Be9+γ→n+Be8(→2α)with negligible, residual radioactivity. The system is shown in Fig. 1. When the target is unpolarized, one expects neutron rates of 1011 epithermal n/s for 1015 Comptons/s and a circulating current of 1 A with polarizations PRHC(n⃗)=-0.5, PLHC(n⃗)=0.5, both with reduced flux, and PLin(n⃗)=0. With a 1 cm thick cylindrical tungsten sheath surrounding the Be to attenuate scattered photons exiting at 90° to the incident photons, there is a peak neutron flux of ≈109 epithermal n/s/cm2 cylindrically symmetric around the surface. No attempt was made to optimize this because there is still no accepted treatment protocol (dose rates or preferred neutron energy distribution). Although these factors depend on the individual case, several thousand BNCT treatments per year appear feasible. A potential clinical

  15. Scalability of the LEU-Modified Cintichem Process: 3-MeV Van de Graaff and 35-MeV Electron Linear Accelerator Studies

    Energy Technology Data Exchange (ETDEWEB)

    Rotsch, David A. [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Brossard, Tom [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Roussin, Ethan [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Quigley, Kevin [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Chemerisov, Sergey [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Gromov, Roman [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Jonah, Charles [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Hafenrichter, Lohman [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Tkac, Peter [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Krebs, John [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Vandegrift, George F. [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division

    2016-10-31

    Molybdenum-99, the mother of Tc-99m, can be produced from fission of U-235 in nuclear reactors and purified from fission products by the Cintichem process, later modified for low-enriched uranium (LEU) targets. The key step in this process is the precipitation of Mo with α-benzoin oxime (ABO). The stability of this complex to radiation has been examined. Molybdenum-ABO was irradiated with 3 MeV electrons produced by a Van de Graaff generator and 35 MeV electrons produced by a 50 MeV/25 kW electron linear accelerator. Dose equivalents of 1.7–31.2 kCi of Mo-99 were administered to freshly prepared Mo-ABO. Irradiated samples of Mo-ABO were processed according to the LEU Modified-Cintichem process. The Van de Graaff data indicated good radiation stability of the Mo-ABO complex up to ~15 kCi dose equivalents of Mo-99 and nearly complete destruction at doses >24 kCi Mo-99. The linear accelerator data indicate that even at 6.2 kCi of Mo-99 equivalence of dose, the sample lost ~20% of Mo-99. The 20% loss of Mo-99 at this low dose may be attributed to thermal decomposition of the product from the heat deposited in the sample during irradiation.

  16. Depth profiling of fingerprint and ink signals by SIMS and MeV SIMS

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, M.J., E-mail: m.bailey@surrey.ac.u [University of Surrey Ion Beam Centre, Surrey GU2 7XH (United Kingdom); Jones, B.N. [University of Surrey Ion Beam Centre, Surrey GU2 7XH (United Kingdom); Hinder, S.; Watts, J. [Surface Analysis Laboratory, University of Surrey, GU2 7XH (United Kingdom); Bleay, S. [Home Office Scientific Development Branch, St. Albans (United Kingdom); Webb, R.P. [University of Surrey Ion Beam Centre, Surrey GU2 7XH (United Kingdom)

    2010-06-15

    Police institutions currently have no analytical method of knowing whether a fingerprint was deposited before or after the document was written or printed. The suitability of using MeV secondary ion mass spectrometry (i.e. SIMS with an MeV ion beam) to determine the order in which a fingerprint and written text were deposited on paper was therefore investigated. A 10 MeV O{sup 4+} beam was used to generate secondary ions from the surface of the samples and to map the molecular fragments from doped fingerprints and inks on paper. The images obtained and the sputtering behaviour of the samples was found to be indicative of the sequence of ink and fingerprint deposits.

  17. Nuclear spin response of sup 40 Ca to 800 MeV polarized protons

    Energy Technology Data Exchange (ETDEWEB)

    Bimbot, L.; Fergerson, R.W.; Glashausser, C.; Jones, K.W.; Baker, F.T.; Beatty, D.; Cupps, V.; Green, A.; Nanda, S. (Institut de Physique Nucleaire, F-91406 Orsay, France (FR) Rutgers University, New Brunswick, NJ 08903 Los Alamos National Laboratory, Los Alamos, New Mexico 87545 University of Georgia, Athens, Georgia 30602 Continuous Electron Beam Accelerator Facility, Newport News, Virginia 23606)

    1990-12-01

    Doubly differential cross sections and spin-flip probabilities have been measured for 800-MeV proton scattering on {sup 40}Ca at 3.2{degree}, 4{degree}, 5{degree}, and 7{degree} in the laboratory, for excitation energies up to 45 MeV. The features of these observables in the continuum are discussed. The data indicate that nuclear spin excitations are enhanced at high excitation energy for angles corresponding to momentum transfers around 100 MeV/{ital c}, as previously observed for incident energies around 300 MeV. The relative nuclear spin response derived from these data is roughly independent of energy. This suggests that the dominance of spin-transfer excitation at high excitation energies for momentum transfers around 100 MeV/{ital c} is an intrinsic feature of the nuclear structure of {sup 40}Ca.

  18. Splitting Behaviour of Implanted MeV Au+ Ions in LiB3O5

    Institute of Scientific and Technical Information of China (English)

    WANG Ke-ming; SHI Bo-rong; Nelson Cue; LU Fei; WANG Feng-xiang; XIE Zhao-xia; SHEN Ding-yu; LIU Yao-gang

    2000-01-01

    The diffusion behaviour of 1.0 and 2.0 MeV Au+ implanted into LiB3O5 single crystal has been studied by the Rutherford backscattering of 2.1 MeV He ions. Annealing was performed at temperatures of 600, 700, and 800℃each for 30min. The results show that the diffusion behaviour is quite different in two cases. In LiB3O5, the depth distribution of the 1.0 Me V Au is nearly Gaussian and becomes bimodal after annealing at 800℃ for 30 min.But in the case of 2.0 MeV, the depth distribution of as implanted Au+ in LiBsO5 has splitting behaviour. After 800C for 30 min annealing, there is no obvious diffusion observed. The precise interpretation is needed.

  19. Study of calf thymus DNA irradiated in vitro with MeV fluorine ions

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A study of the fragments of DNA irradiated with MeV ions is important for the understanding of the DNA damage mechanism and the subsequent biological effects (induced by heavy ions). In this experiment, the products of calf thymus DNA (CT DNA) irradiated with MeV fluorine ions were analyzed using agarose gel electrophoresis,modified time-of-flight mass spectrometer (MALDI-TOF), and high-performance liquid chromatography (HPLC).The results showed that the molecular mass of the fragments were concentrated around 831 bp with agarose gel electrophoresis, there was no observable product in the range of 1,000- 30,000 (m/q) using MALDI-TOF, and small biomolecules were separated from the products. The results of this study indicated that the strand breaks of calf thymus DNA induced by MeV fluorine ions were nonrandom.

  20. 25 MeV Solar Proton Events in Cycle 24 and Previous Cycles

    Science.gov (United States)

    Richardson, I. G.; Cane, H. V.; von Rosenvinge, T. T.

    2014-12-01

    We summarize observations of nearly 1000 solar energetic particle events that include 25 MeV protons made by Goddard instruments on various spacecraft (IMPs IV, V, 7, 8, ISEE-3) and by other instruments on SOHO, since 1967, encompassing solar cycles 20 to 24. We also include recent observations of such events from the STEREO spacecraft. These extended observations place studies focusing on Cycles 23 and 24 in a broader context. For example, the time distribution of 25 MeV proton events varies from cycle to cycle such that each cycle is unique. In the current cycle, ~25 MeV proton events were absent during the preceding solar minimum, whereas earlier minima showed occasional, often reasonably intense events, and there have been, so far, fewer exceptionally intense events compared to Cycles 22 and 23, though Cycle 21 also apparently lacked such events.