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Sample records for axion solar telescope

  1. CAST-CERN Axion Solar Telescope

    International Nuclear Information System (INIS)

    CAST (CERN Axion Solar Telescope) is a helioscope looking for axions coming from the solar core to the Earth. The experiment, located at CERN, is based on the Primakoff effect and uses a magnetic field of 9 T provided by a decommissioned LHC magnet. CAST is able to follow the Sun during sunrise and sunset and therefore three X-ray detectors are mounted on both ends of the magnet waiting for a photon from axion-to-photon conversion due to Primakoff effect. During its first phase, which concluded in 2004, CAST has been looking for axions with masses up to 0.02 eV. The second phase did already start and first data were taken in December 2005. CAST's second phase manages to reestablish the coherence needed to scan for axions with masses up to 0.83 eV by using a buffer gas. This enables the experiment to look into the theoretical regions for axions

  2. The CERN axion solar telescope (CAST)

    CERN Document Server

    Aalseth, C E; Autiero, D; Avignone, F T; Barth, K; Bowyer, S M; Bräuninger, H; Brodzinski, R L; Carmona, J M; Cebrián, S; Celebi, G; Cetin, S A; Collar, J I; Creswick, R; Delbart, A; Delattre, M; Di Lella, L; De Oliveira, R; Eleftheriadis, C; Erdutan, N; Fanourakis, G K; Farach, H A; Fiorini, C; Geralis, T; Giomataris, Ioanis; Girard, T A; Gninenko, S N; Golubev, N A; Hasinoff, M D; Hoffmann, D; Irastorza, I G; Jacoby, J; Jeanneau, F; Knopf, M A; Kovzelev, A; Kotthaus, R; Krcmar, M; Krecak, Z; Lakic, B; Liolios, A; Ljubicic, A; Lutz, Gerhard; Longoni, A; Luzón, G; Mailov, A; Matveev, V A; Miley, H S; Morales, A; Morales, J; Mutterer, M; Nikolaidis, A; Nussinov, S; Ortiz, A; Pitts, W K; Placci, A; Postoev, V E; Raffelt, G G; Riege, H; Sampietro, M; Sarsa, M; Savvidis, I; Stipcevic, M; Thomas, C W; Thompson, R C; Valco, P; Villar, J A; Villierme, B; Walckiers, L; Wilcox, W; Zachariadou, K; Zioutas, Konstantin

    2002-01-01

    A decommissioned LHC test magnet is being prepared as the CERN Axion Solar Telescope (CAST) experiment. The magnet has a field of 9.6 Tesla and length of 10 meters. It is being mounted on a platform to track the sun over +-8 deg. vertically and +-45 deg. , horizontally. A sensitivity in axion-photon coupling g alpha gamma gamma < 5 x 10 sup - sup 1 sup 1 GeV sup - sup 1 can be reached for m subalpha <= 10 sup - sup 2 eV, and with a gas filled tube-can reach g alpha gamma gamma <= 10 sup - sup 1 sup 0 GeV sup - sup 1 for axion masses m subalpha < 2eV.

  3. Prospects for the CERN Axion Solar Telescope Sensitivity to 14.4 keV Axions

    CERN Document Server

    Jakovcic, K; Aune, S; Avignone, F T; Barth, K; Belov, A; Beltrn, B; Bruninger, H; Carmona, J M; Cebrin, S; Collar, J I; Dafni, T; Davenport, M; Di Lella, L; Eleftheriadis, C; Fanourakis, G K; Ferrer-Ribas, E; Fischer, H; Franz, J; Friedrich, P; Geralis, T; Giomataris, Ioanis; Gninenko, S; Hasinoff, M D; Heinsius, F H; Hoffmann, Dieter H H; Irastorza, I G; Jacoby, J; Kang, D; Knigsmann, K; Kotthaus, R; Krcmar, M; Kousouris, a K; Kuster, M; Laki, B; Lasseur, C; Liolios, A; Ljubici, A; Lutz, G; Luzn, G; Miller, D W; Morales, A; Morales, J; Ortiz, A; Papaevangelou, T; Placci, A; Raffelt, G; Ruz, J; Riege, H; Semertzidis, Y K; Serpico, Pasquale Dario; Stewart, o L; Vieira, J D; Villar, J; Vogel, J; Walckiers, L; Zioutas, K; Jakovcic, Kresimir

    2007-01-01

    The CERN Axion Solar Telescope (CAST) is searching for solar axions using the 9.0 T strong and 9.26 m long transverse magnetic field of a twin aperture LHC test magnet, where axions could be converted into X-rays via reverse Primakoff process. Here we explore the potential of CAST to search for 14.4 keV axions that could be emitted from the Sun in M1 nuclear transition between the first, thermally excited state, and the ground state of 57Fe nuclide. Calculations of the expected signals, with respect to the axion-photon coupling, axion-nucleon coupling and axion mass, are presented in comparison with the experimental sensitivity.

  4. The cern axion solar telescope (CAST): an update

    Science.gov (United States)

    Andriamonje, S.; Arsov, V.; Aune, S.; Aune, T.; Avignone, F. T.; Barth, K.; Belov, A.; Beltran, B.; Bräuninger, H.; Carmona, J.; Cebrián, S.; Chesi, E.; Cipolla, G.; Collar, J.; Creswick, R.; Dafni, T.; Davenport, M.; Dedousis, S.; Delattre, M.; Delbart, A.; Deoliveira, R.; Dilella, L.; Eleftheriadis, C.; Engelhauser, J.; Fanourakis, G.; Farach, H.; Ferrer, E.; Fischer, H.; Formenti, F.; Franz, J.; Friedrich, P.; Geralis, T.; Giomataris, I.; Gninenko, S.; Golubev, N.; Hartmann, R.; Hasinoff, M.; Heinsius, F.-H.; Hoffmann, D. H. H.; Irastorza, I.; Jacoby, J.; Joux, J.-N.; Kang, D.; Königsmann, K.; Kotthaus, R.; Krcmar, M.; Kuster, M.; Lakic, B.; Lasseur, C.; Liolios, A.; Lippitsch, A.; Ljubicic, A.; Lutz, G.; Luzon, G.; Morales, A.; Morales, J.; Mutterer, M.; Nikolaidis, A.; de Solorzano, A. Ortiz; Papaevangelou, T.; Placci, A.; Raffelt, G.; Rammos, P.; Robert, J. P.; Ruz, J.; Sarsa, M.; Schill, C.; Serber, W.; Semertzidis, Y.; Vieira, J.; Villar, J.; Vullierme, B.; Walckiers, L.; Zioutas, K.

    2005-01-01

    The CERN Axion Solar Telescope (CAST), a 10 meter long LHC, 9 Tesla, test magnet is mounted on a moving platform that tracks the sun about 1.5 hours during sunrise, again during sunset. It moves ±80 vertically and ±400 horizontally. It has been taking data continuously since July 10, 2003. Data analyzed thus far yield an upper bound on the photon-axion coupling constant, gaγγ ⩽ 3 × 10-10 GeV-1 for axion masses less than 5 × 10-2 eV.

  5. The CERN axion solar telescope (CAST): an update

    International Nuclear Information System (INIS)

    The CERN Axion Solar Telescope (CAST), a 10 meter long LHC, 9 Tesla, test magnet is mounted on a moving platform that tracks the sun about 1.5 hours during sunrise, again during sunset. It moves ±80 vertically and ±400 horizontally. It has been taking data continuously since July 10, 2003. Data analyzed thus far yield an upper bound on the photon-axion coupling constant, g aγγ 3 x 10-10 GeV-1 for axion masses less than 5 x 10-2 eV

  6. First results from the CERN Axion Solar Telescope

    International Nuclear Information System (INIS)

    Hypothetical axionlike particles with a two-photon interaction would be produced in the sun by the Primakoff process. In a laboratory magnetic field ('axion helioscope'), they would be transformed into x-rays with energies of a few keV. Using a decommissioned Large Hadron Collider test magnet, the CERN Axion Solar Telescope ran for about 6 months during 2003. The first results from the analysis of these data are presented here. No signal above background was observed, implying an upper limit to the axion-photon coupling gaγ-10 GeV-1 at 95% C.L. for ma < or approx. 0.02 eV. This limit, assumption-free, is comparable to the limit from stellar energy-loss arguments and considerably more restrictive than any previous experiment over a broad range of axion masses

  7. Search for Solar Axions with the CCD Detector and X-ray Telescope at CAST Experiment

    OpenAIRE

    Rosu, Madalin-Mihai

    2015-01-01

    The CERN Axion Solar Telescope (CAST) is an experiment that uses the world’s highest sensitivity Helioscope to date for solar Axions searches. Axions are weakly interacting pseudoscalar particles proposed to solve the so-called Strong Charge-Parity Problem of the Standard Model. The principle of detection is the inverse Primakoff Effect, which is a mechanism for converting the Axions into easily detectable X-ray photons in a strong transverse magnetic field. The solar Axions are produced d...

  8. Latest results and prospects of the CERN Axion Solar Telescope

    OpenAIRE

    2011-01-01

    The CERN Axion Solar Telescope (CAST) experiment searches for axions from the Sun converted into few keV photons via the inverse Primakoff effect in the high magnetic field of a superconducting Large Hadron Collider (LHC) decommissioned test magnet. After results obtained with vacuum in the magnet pipes (phase I of the experiment) as well as with 4He the collaboration is now immersed in the data taking with 3He, to be finished in 2011. The status of the experiment will be presented, including...

  9. Search for sub-ev mass solar axions by the cern axion solar telescope with he-3 buffer gas

    OpenAIRE

    Çetin, Serkant Ali; CAST Collaboration

    2011-01-01

    The CERN Axion Solar Telescope (CAST) has extended its search for solar axions by using He-3 as a buffer gas. At T = 1.8 K this allows for larger pressure settings and hence sensitivity to higher axion masses than our previous measurements with He-4. With about 1 h of data taking at each of 252 different pressure settings we have scanned the axion mass range 0.39 eV less than or similar to m(a) less than or similar to 0.64 eV. From the absence of excess x rays when the magnet was pointing to ...

  10. Search for Sub-eV Mass Solar Axions by the CERN Axion Solar Telescope with 3He Buffer Gas

    International Nuclear Information System (INIS)

    The CERN Axion Solar Telescope (CAST) has extended its search for solar axions by using 3He as a buffer gas. At T=1.8 K this allows for larger pressure settings and hence sensitivity to higher axion masses than our previous measurements with 4He. With about 1 h of data taking at each of 252 different pressure settings we have scanned the axion mass range 0.39 eV a aγ -10 GeV-1 at 95% C.L., the exact value depending on the pressure setting. Kim-Shifman-Vainshtein-Zakharov axions are excluded at the upper end of our mass range, the first time ever for any solar axion search. In the future we will extend our search to ma < or approx. 1.15 eV, comfortably overlapping with cosmological hot dark matter bounds.

  11. Latest results and prospects of the CERN Axion Solar Telescope

    Energy Technology Data Exchange (ETDEWEB)

    Irastorza, I G; Carmona, J M; Dafni, T; Galan, J [Instituto de Fisica Nuclear y Altas EnergIas, Universidad de Zaragoza, Zaragoza (Spain); Aune, S; Ferrer-Ribas, E [IRFU, Centre d' Etudes Nucleaires de Saclay (CEA-Saclay), Gif-sur-Yvette (France); Barth, K; Borghi, S; Davenport, M; Elias, N [European Organization for Nuclear Research (CERN), Geneve (Switzerland); Belov, A [Institute for Nuclear Research (INR), Russian Academy of Sciences, Moscow (Russian Federation); Braeuninger, H; Friedrich, P [Max-Planck-Institut fuer extraterrestrische Physik, Garching (Germany); Cantatore, G [Instituto Nazionale di Fisica Nucleare (INFN), Sezione di Trieste and Universita di Trieste, Trieste (Italy); Cetin, S A; Ezer, C [Dogus University, Istanbul (Turkey); Collar, J I [Enrico Fermi Institute and KICP, University of Chicago, Chicago, IL (United States); Eleftheriadis, C [Aristotle University of Thessaloniki, Thessaloniki (Greece); Fanourakis, G [National Center for Scientific Research ' Demokritos' , Athens (Greece); Gardikiotis, A, E-mail: Igor.Irastorza@cern.ch [Physics Department, University of Patras, Patras (Greece)

    2011-08-10

    The CERN Axion Solar Telescope (CAST) experiment searches for axions from the Sun converted into few keV photons via the inverse Primakoff effect in the high magnetic field of a superconducting Large Hadron Collider (LHC) decommissioned test magnet. After results obtained with vacuum in the magnet pipes (phase I of the experiment) as well as with {sup 4}He the collaboration is now immersed in the data taking with {sup 3}He, to be finished in 2011. The status of the experiment will be presented, including a preliminary exclusion plot of the first {sup 3}He data. CAST is currently sensitive to realistic QCD axion models at the sub-eV scale, and with axion-photon couplings down to the {approx} 2 x 10{sup -10} GeV{sup -1}, compatible with solar life limits. Future plans include revisiting vaccuum and {sup 4}He configurations with improved sensitivity, as well as possible additional search for non-standard signals from chamaleons, paraphotons or other WISPs. For the longer term, we study the feasibility of an altogether improved version of the axion helioscope concept, with a jump in sensitivity of about one order of magnitude in g{sub a}{gamma} beyond CAST.

  12. Search for sub-eV mass solar axions by the CERN Axion Solar Telescope with 3He buffer gas.

    Science.gov (United States)

    Arik, M; Aune, S; Barth, K; Belov, A; Borghi, S; Bräuninger, H; Cantatore, G; Carmona, J M; Cetin, S A; Collar, J I; Dafni, T; Davenport, M; Eleftheriadis, C; Elias, N; Ezer, C; Fanourakis, G; Ferrer-Ribas, E; Friedrich, P; Galán, J; García, J A; Gardikiotis, A; Gazis, E N; Geralis, T; Giomataris, I; Gninenko, S; Gómez, H; Gruber, E; Guthörl, T; Hartmann, R; Haug, F; Hasinoff, M D; Hoffmann, D H H; Iguaz, F J; Irastorza, I G; Jacoby, J; Jakovčić, K; Karuza, M; Königsmann, K; Kotthaus, R; Krčmar, M; Kuster, M; Lakić, B; Laurent, J M; Liolios, A; Ljubičić, A; Lozza, V; Lutz, G; Luzón, G; Morales, J; Niinikoski, T; Nordt, A; Papaevangelou, T; Pivovaroff, M J; Raffelt, G; Rashba, T; Riege, H; Rodríguez, A; Rosu, M; Ruz, J; Savvidis, I; Silva, P S; Solanki, S K; Stewart, L; Tomás, A; Tsagri, M; van Bibber, K; Vafeiadis, T; Villar, J A; Vogel, J K; Yildiz, S C; Zioutas, K

    2011-12-23

    The CERN Axion Solar Telescope (CAST) has extended its search for solar axions by using (3)He as a buffer gas. At T=1.8 K this allows for larger pressure settings and hence sensitivity to higher axion masses than our previous measurements with (4)He. With about 1 h of data taking at each of 252 different pressure settings we have scanned the axion mass range 0.39 eV≲m(a)≲0.64 eV. From the absence of excess x rays when the magnet was pointing to the Sun we set a typical upper limit on the axion-photon coupling of g(aγ)≲2.3×10(-10) GeV(-1) at 95% C.L., the exact value depending on the pressure setting. Kim-Shifman-Vainshtein-Zakharov axions are excluded at the upper end of our mass range, the first time ever for any solar axion search. In the future we will extend our search to m(a)≲1.15 eV, comfortably overlapping with cosmological hot dark matter bounds. PMID:22243149

  13. CrossRef The CERN Axion Solar Telescope

    CERN Document Server

    Hasinoff, M D; Arik, E; Autiero, D; Avignone, F; Barth, K; Bingol, E; Brauninger, H; Brodzinski, R; Carmona, J; Chesi, E; Cebrian, S; Cetin, S; Collar, J; Creswick, R; Dafni, T; De Oliveira, R; Dedoussis, S; Delbart, A; Di Lella, L; Eleftheriadis, C; Fanourakis, G; Farach, H; Fischer, H; Formenti, F; Geralis, T; Giomataris, I; Gninenko, S; Goloubev, N; Hartmann, R; Hoffmann, D; Irastorza, I G; Jacoby, J; Kang, D; Konigsmann, K; Kotthaus, R; Krcmar, M; Kuster, M; Lakic, B; Liolios, A; LJubicic, A; Lutz, G; Luzon, G; Miley, H; Morales, A; Morales, J; Mutterer, M; Nikolaidis, A; Ortiz, A; Papaevangelou, T; Placci, A; Raffelt, G; Riege, H; Sarsa, M; Savvidis, I; Schopper, R; Semertzidis, I; Spano, C; Villar, J; Vullierme, B; Walckiers, L; Zachariadou, K; Zioutas, K

    2003-01-01

    The CAST experiment at CERN is using a decommissioned LHC prototype magnet to search for solar axions through their Primakoff conversion into x-ray photons. The magnet (B = 9.0 Tesla, L = 10 m) can track the sun each day for a total exposure time of ~180 minutes (sunrise + sunset). We expect to reach a sensitivity in axion-photon coupling, gaγγ ≲ 5 × 10-11 GeV-1 for ma ≲ 10-2 eV after ˜1 year's running time. By filling the beam tube with 4He or 3He gas we should be able to extend the sensitive axion mass region into the eV mass range.

  14. Search for solar axions with the Time Projection Chamber of the CERN Axion Solar Telescope with 4-Helium as buffer gas

    CERN Document Server

    Ruz, J; García Irastorza, I

    CAST (CERN Axion Solar Telescope) is a helioscope looking for axions coming from the solar core to the Earth. The experiment, located at CERN, is based on the Primakoff effect and uses a magnetic field of 9 Tesla provided by a decommissioned LHC magnet. CAST is able to follow the Sun during sunrise and sunset and, therefore, different X-ray detectors are mounted on both ends of the magnet waiting for a photon from axion-to-photon conversion due to the Primakoff effect. During its First Phase, which concluded in 2004, the TPC detector of CAST looked for axions with masses up to 0.02 eV. By using a Helium-4 buffer gas, CAST's TPC detector has been able to re-establish the coherence needed to scan for axions with masses up to 0.39 eV, technique that allows CAST to look into the theoretical regions for axions.

  15. Search for Solar Axions with the CCD Detector and X-ray Telescope at CAST Experiment

    CERN Document Server

    Rosu, Madalin Mihai; Zioutas, Konstantin

    2015-06-09

    The CERN Axion Solar Telescope (CAST) is an experiment that uses the world’s highest sensitivity Helioscope to date for solar Axions searches. Axions are weakly interacting pseudoscalar particles proposed to solve the so-called Strong Charge-Parity Problem of the Standard Model. The principle of detection is the inverse Primakoff Effect, which is a mechanism for converting the Axions into easily detectable X-ray photons in a strong transverse magnetic field. The solar Axions are produced due to the Primakoff effect in the hot and dense core of from the coupling of a real and a virtual photon. The solar models predict a peak Axion luminosity at an energy of 3 keV originating mostly from the inner 20% of the solar radius. Thus an intensity peak at an energy of 3 keV is also expected in the case of the X-ray radiation resulting from Axion conversion. CAST uses a high precision movement system for tracking the Sun twice a day with a LHC dipole twin aperture prototype magnet, 9.26 meters long and with a field of...

  16. Search for solar axions with the X-ray telescope of the CAST experiment (phase II)

    International Nuclear Information System (INIS)

    The CAST (CERN Solar Axion Telescope) experiment is searching for solar axions by their conversion into photons inside a transverse magnetic field. So far, no solar axionsignal has been detected, but a new upper limit could be given (CAST Phase I). Since 2005, CAST entered in its second phase where it operates with a buffer gas (4He) in the conversion region to extend the sensitivity of the experiment to higher axionmasses. For the first time it is possible to enter the theoretically favored axion massrange and to give an upper limit for this solar axion mass-range (>0.02 eV). This thesis is about the analysis of the X-ray telescope data Phase II with 4He inside the magnet. The result for the coupling constant of axions to photons is: gαγγ-10 GeV-1 (95%C.L.) for ma=0.02-0.4 eV. (2) This result is better than any result that has been given before in this mass range for solar axions. (orig.)

  17. The CERN Axion Solar Telescope (CAST): Status and Prospects

    International Nuclear Information System (INIS)

    The CAST experiment is being mounted at CERN. It will make use of a decommissioned LHC test magnet to look for solar axions through its conversion into Photons inside the magnetic field. The magnet has a field of 9.6 Tesla and length of 10 m and is installed in a platform which allows to move it ±8 degrees vertically and ±40 degrees horizontally. According to these numbers we expect a sensitivity in axion-photon coupling gaγγ ∼-11 GeV-1 for ma ∼-2 eV, and with a gas filled tube gaγγ ∼-10 GeV-1 for ma ∼< 2 eV.

  18. Cryogenics for the CERN Solar Axion Telescope (CAST) using a LHC Dipole Prototype Magnet

    CERN Document Server

    Barth, K; Pezzetti, M; Pirotte, O; Riege, H; Vullierme, B; Walckiers, L; Zioutas, Konstantin

    2002-01-01

    The axion, an as yet hypothetical particle predicted from the solution of the strong CP problem, constitutes a prime candidate for the galactic dark matter and also arises in supersymmetry and superstring theories. If existing, axions should be copiously produced in stellar interiors and there are theoretical expectations for a low-energy axion emission spectrum peaked around a mean energy of ~ 4.4 keV. To provide the experimental proof, a solar axion telescope is at present installed at CERN, which is expected to be in total 10-12 times more efficient than the present largest set-up in operation at the University of Tokyo. The telescope will use a decommissioned 10-m long LHC superconducting dipole prototype magnet, providing a magnetic field of 9 T in operation, to catalyse the solar axion to photon conversion, which then can be detected by low-background x-ray detectors. The paper describes the external and proximity cryogenic systems and their integration into the overall telescope assembly.

  19. Search for Solar Axions by the CERN Axion Solar Telescope with 3 He Buffer Gas: Closing the Hot Dark Matter Gap

    CERN Document Server

    Arik, M; Barth, K.; Belov, A.; Borghi, S.; Brauninger, H.; Cantatore, G.; Carmona, J.M.; Cetin, S.A.; Collar, J.I.; Da Riva, E.; Dafni, T.; Davenport, M.; Eleftheriadis, C.; Elias, N.; Fanourakis, G.; Ferrer-Ribas, E.; Friedrich, P.; Galan, J.; Garcia, J.A.; Gardikiotis, A.; Garza, J.G.; Gazis, E.N.; Geralis, T.; Georgiopoulou, E.; Giomataris, I.; Gninenko, S.; Gomez, H.; Gomez Marzoa, M.; Gruber, E.; Guthorl, T.; Hartmann, R.; Hauf, S.; Haug, F.; Hasinoff, M.D.; Hoffmann, D.H.H.; Iguaz, F.J.; Irastorza, I.G.; Jacoby, J.; Jakovcic, K.; Karuza, M.; Konigsmann, K.; Kotthaus, R.; Krcmar, M.; Kuster, M.; Lakic, B.; Lang, P.M.; Laurent, J.M.; Liolios, A.; Ljubicic, A.; Lozza, V.; Luzon, G.; Neff, S.; Niinikoski, T.; Nordt, A.; Papaevangelou, T.; Pivovaroff, M.J.; Raffelt, G.; Riege, H.; Rodriguez, A.; Rosu, M.; Ruz, J.; Savvidis, I.; Shilon, I.; Silva, P.S.; Solanki, S.K.; Stewart, L.; Tomas, A.; Tsagri, M.; van Bibber, K.; Vafeiadis, T.; Villar, J.; Vogel, J.K.; Yildiz, S.C.; Zioutas, K.

    2014-01-01

    The CERN Axion Solar Telescope (CAST) has finished its search for solar axions with 3^He buffer gas, covering the search range 0.64 eV < m_a <1.17 eV. This closes the gap to the cosmological hot dark matter limit and actually overlaps with it. From the absence of excess X-rays when the magnet was pointing to the Sun we set a typical upper limit on the axion-photon coupling of g_ag < 3.3 x 10^{-10} GeV^{-1} at 95% CL, with the exact value depending on the pressure setting. Future direct solar axion searches will focus on increasing the sensitivity to smaller values of g_a, for example by the currently discussed next generation helioscope IAXO.

  20. Background study for the pn-CCD detector of CERN Axion Solar Telescope

    OpenAIRE

    Cebrián, S.; Rodríguez, A; M. Kuster(Technische Universität Darmstadt); Beltrán, B; Carmona, J.M.; H Gómez; Hartmann, R.; Irastorza, I. G.; R. Kotthaus; Luzón, G.; MORALES, J., CRUZ, D., DELGADO, P., LIZANA, M., LÓPEZ, V.; de Solórzano, A. Ortiz(Laboratorio de Física Nuclear y Astropartículas, Universidad de Zaragoza, Calle Pedro Cerbuna 12, 50009, Zaragoza, Spain); Ruz, J.; Strüder, L.; Villar, J. A.

    2007-01-01

    The CERN Axion Solar Telescope (CAST) experiment searches for axions from the Sun converted into photons with energies up to around 10 keV via the inverse Primakoff effect in the high magnetic field of a superconducting Large Hadron Collider (LHC) prototype magnet. A backside illuminated pn-CCD detector in conjunction with an X-ray mirror optics is one of the three detectors used in CAST to register the expected photon signal. Since this signal is very rare and different background components...

  1. First results from the CERN Axion Solar Telescope (CAST)

    CERN Document Server

    Andriamonje, Samuel A; Aune, S; Autiero, D; Barth, K; Belov, A; Beltran, B; Bräuninger, H; Carmona, J M; Cebrián, S; Chesi, Enrico Guido; Collar, J I; Creswick, R; Dafni, T; Davenport, M; Di Lella, L; Englhauser, J; Fanourakis, G K; Farach, H A; Ferrer, E; Fischer, H; Franz, J; Friedrich, P; Geralis, T; Giomataris, Ioanis; Gninenko, S; Goloubev, N; Hasinoff, M D; Heinsius, F H; Hoffmann, Dieter H H; Irastorza, I G; Jacoby, J; Kang, D; Königsmann, K C; Kotthaus, R; Krcmar, M; Kousouris, K; Kuster, M; Lakic, B; Lasseur, C; Liolios, A; Ljubicic, A; Lutz, Gerhard; Luzón, G; Miller, D W; Morales, A; Mutterer, M; Nikolaidis, A; Ortiz, A; Papaevangelou, T; Placci, A; Raffelt, Georg G; Ruz, J; Riege, H; Sarsa, M L; Savvidis, I; Serber, W; Serpico, Pasquale Dario; Semertzidis, Y K; Vieira, J D; Villar, José Angel; Walckiers, L; Zachariadou, K; Zioutas, Konstantin

    2005-01-01

    Hypothetical axion-like particles with a two-photon interaction would be produced in the Sun by the Primakoff process. In a laboratory magnetic field (``axion helioscope'') they would be transformed into X-rays with energies of a few keV. Using a decommissioned LHC test magnet, CAST has been running for about 6 months during 2003. The first results from the analysis of these data are presented here. No signal above background was observed, implying an upper limit to the axion-photon coupling < 1.16 10^{-10} GeV^-1 at 95% CL for m_a <~0.02 eV. This limit is comparable to the limit from stellar energy-loss arguments and considerably more restrictive than any previous experiment in this axion mass range.

  2. Background study for the pn-CCD detector of CERN Axion Solar Telescope

    CERN Document Server

    Cebrián, S; Kuster, M; Beltrán, B; Carmona, J M; Gómez, H; Hartmann, R; Irastorza, I G; Kotthaus, R; Luzón, G; Morales, J; de Solórzano, A Ortiz; Ruz, J; Strüder, L; Villar, J A

    2007-01-01

    The CERN Axion Solar Telescope (CAST) experiment searches for axions from the Sun converted into photons with energies up to around 10 keV via the inverse Primakoff effect in the high magnetic field of a superconducting Large Hadron Collider (LHC) prototype magnet. A backside illuminated pn-CCD detector in conjunction with an X-ray mirror optics is one of the three detectors used in CAST to register the expected photon signal. Since this signal is very rare and different background components (environmental gamma radiation, cosmic rays, intrinsic radioactive impurities in the set-up, ...) entangle it, a detailed study of the detector background has been undertaken with the aim to understand and further reduce the background level of the detector. The analysis is based on measured data taken during the Phase I of CAST and on Monte Carlo simulations of different background components. This study will show that the observed background level (at a rate of (8.00+-0.07)10^-5 counts/cm^2/s/keV between 1 and 7 keV) s...

  3. Axion searches at CERN with the CAST Telescope

    OpenAIRE

    al, C. Eleftheriadis et

    2003-01-01

    The CERN Axion Solar Telescope (CAST) searches for axions coming from photon to axion conversion in the sun's core, as stated by the Primakoff effect. Axions arise in particle physics as a consequence of the breaking of Peccei-Quinn symmetry which has been introduced as a solution to the strong CP problem. As cosmological axions they are candidates for at least some part of cold Dark Matter.They are also expected to be produced copiously in stellar interiors with energies as high as the therm...

  4. Axion searches at CERN with the CAST Telescope

    CERN Document Server

    Eleftheriadis, C; Arik, E; Autiero, D; Avignone, F T; Barth, K; Bingol, E; Bräuninger, H; Brodzinski, R L; Carmona, J M; Cebrián, S; Cetin, S A; Chesi, Enrico Guido; Cipolla, G; Collar, J I; Creswick, R; Dafni, T; Davenport, M; De Oliveira, R; Dedoussis, S; Delbart, A; Di Lella, L; Fanourakis, G K; Farach, H A; Fischer, H; Formenti, F; Geralis, T; Glomataris, I; Gninenko, S N; Goloubev, N; Hartmann, R; Hasinoff, M D; Hoffmann, D; Irastorza, I G; Jacoby, J; Kang, D; Königsmann, K C; Kotthaus, R; Krcmar, M; Kuster, M; Lakic, B; Liolios, A; Ljubicic, A; Lutz, Gerhard; Luzón, G; Miley, H S; Morales, A; Morales, L; Mutterer, M; Nikolaidis, A; Ortiz, A; Papaevangelou, T; Placci, A; Raffelt, Georg G; Riege, H; Sarsa, M; Savvidis, I; Schopper, R; Semertzidis, Y K; Spanos, V C; Vasilelou, V; Villar, José Angel; Vullierme, B; Walckiers, L; Zachariadou, K; Zioutas, Konstantin

    2003-01-01

    The CERN Axion Solar Telescope (CAST) searches for axions coming from photon to axion conversion in the sun's core, as stated by the Primakoff effect. Axions arise in particle physics as a consequence of the breaking of Peccei-Quinn symmetry which has been introduced as a solution to the strong CP problem. As cosmological axions they are candidates for at least some part of cold Dark Matter.They are also expected to be produced copiously in stellar interiors with energies as high as the thermal photons undergoing photon to axion conversion. In our sun the axion energy spectrum peaks at about 4.4 keV, extending up to 10 keV. CAST collected preliminary data in 2002 and data taking with its full capability will start in the beginning of 2003.

  5. Solar axion search with the CAST experiment

    CERN Document Server

    Arik, E; Autiero, D; Barth, K; Belov, A; Beltrán, B; Borghi, S; Boydag, F S; Bräuninger, H; Cantatore, G; Carmona, J M; Cetin, S A; Collar, J I; Dafni, T; Davenport, M; Di Lella, L; Dogan, O B; Eleftheriadis, C; Elias, N; Fanourakis, G K; Ferrer-Ribas, E; Fischer, H; Franz, J; Galan, J; Gazis, E; Geralis, T; Giomataris, Yu; Gninenko, S; Gomez, H; Hasinoff, M; Heinsius, F H; Hikmet, I; Hoffmann, D H H; Irastorza, I G; Jacoby, J; Jakovcic, K; Kang, D; Karageorgopoulou, T; Karuza, M; Königsmann, K C; Kotthaus, R; Krcmar, M; Kousouris, K; Kuster, M; Lakic, B; Lasseur, C; Liolios, A; Ljubcici, A; Lozza, V; Lutz, G; Luzón, G; Miller, D; Morales, J; Niinikoski, T; Nordt, A; Ortiz, A; Papaevangelou, T; Pivovaroff, M; Placci, A; Raiteri, G; Raffelt, G; Riege, H; Rodríguez, A; Ruz, J; Savvidis, I; Semertzidis, Y; Serpico, P; Solanki, S K; Soufli, R; Stewart, L; Tsagri, M; Van Bibber, K; Villar, J; Vogel, J; Walckiers, L; Zioutas, K

    2008-01-01

    The CAST (CERN Axion Solar Telescope) experiment is searching for solar axions by their conversion into photons inside the magnet pipe of an LHC dipole. The analysis of the data recorded during the first phase of the experiment with vacuum in the magnet pipes has resulted in the most restrictive experimental limit on the coupling constant of axions to photons. In the second phase, CAST is operating with a buffer gas inside the magnet pipes in order to extent the sensitivity of the experiment to higher axion masses. We will present the first results on the $^4{He}$ data taking as well as the system upgrades that have been operated in the last year in order to adapt the experiment for the $^3{He}$ data taking. Expected sensitivities on the coupling constant of axions to photons will be given for the recent $^3{He}$ run just started in March 2008.

  6. Experimental search for solar axions

    International Nuclear Information System (INIS)

    A new technique has been used to search for solar axions using a single crystal germanium detector. It exploits the coherent conversion of axions into photons when their angle of incidence satisfies a Bragg condition with a crystalline plane. The analysis of approximately 1.94 kg.yr of data from the 1 kg DEMOS detector in Sierra Grande, Argentina, yields a new laboratory bound on axion-photon coupling of gαγγ -9 GeV-1, independent of axion mass up to ∼ 1 keV

  7. Axion Searches, Old and New

    CERN Document Server

    CERN. Geneva

    2005-01-01

    Outline of the lecture: Constraints from laboratory searches and astrophysics, axion cosmology, the cavity detector of dark matter axions, solar axion searches, laser experiments, a telescope search, macroscopic forces mediated by axions.

  8. Search for solar axions with the X-ray telescope of the CAST experiment (phase II); Suche nach solaren Axionen mit dem Roentgenteleskop des CAST-Experiments (Phase II)

    Energy Technology Data Exchange (ETDEWEB)

    Nordt, Annika

    2009-10-14

    The CAST (CERN Solar Axion Telescope) experiment is searching for solar axions by their conversion into photons inside a transverse magnetic field. So far, no solar axionsignal has been detected, but a new upper limit could be given (CAST Phase I). Since 2005, CAST entered in its second phase where it operates with a buffer gas ({sup 4}He) in the conversion region to extend the sensitivity of the experiment to higher axionmasses. For the first time it is possible to enter the theoretically favored axion massrange and to give an upper limit for this solar axion mass-range (>0.02 eV). This thesis is about the analysis of the X-ray telescope data Phase II with {sup 4}He inside the magnet. The result for the coupling constant of axions to photons is: g{sub {alpha}}{sub {gamma}}{sub {gamma}}<1.6-6.0 x 10{sup -10} GeV{sup -1} (95%C.L.) for m{sub a}=0.02-0.4 eV. (2) This result is better than any result that has been given before in this mass range for solar axions. (orig.)

  9. Search for Solar Axions with the CAST-Experiment

    CERN Document Server

    Vogel, J.; Aune, S.; Autiero, D.; Barth, K.; Belov, A.; Beltran, B.; Borghi, S.; Bourlis, G.; Boydag, F. S.; Brauninger, H.; Carmona, J.; Cebrian, S.; Cetin, S. A.; Collar, J.I.; Dafni, T.; Davenport, M.; Di Lella, L.; Dogan, O. B.; Elefheriadis, C.; Elias, N.; Fanourakis, G.; Ferrer-Ribas, E.; Fisher, H.; Franz, J.; Galan, J.; Geralis, T.; Giomataris, I.; Gninenko, S.; Gomez, H.; Hasinoff, M.; Heinsius, H.; Hikmet, I.; Hoffmann, D. H. H.; Irastorza, I. G.; Jacoby, J.; Jakovcic, K.; Kang, D.; Konigsmann, K.; Kotthaus, R.; Krcmar, M.; Kousouris, K.; Kuster, M.; Lakic, B.; Lasseur, C.; Liolios, A.; Ljubicic, A.; Lutz, G.; Luzon, G.; Miller, D.; Morales, J.; Niinikoski, T.; Nordt, A.; Ortiz, A.; Papaevangelou, T.; Pivovaroff, M.; Placci, A.; Raffelt, G.; Riege, H.; Rodriguez, A.; Ruz, J.; Savvidis, I.; Semertzidis, Y.; Serpico, P.; Soufli, R.; Stewart, L.; Tzamarias, S.; Van Bibber, K.; Villar, J.; Walckiers, L.; Zioutas, K.; Morales, A.

    2008-01-01

    Solar axions can be produced in the Sun via the so-called Primakoff effect. The CERN Axion Solar Telescope (CAST) uses an LHC prototype magnet of about 9 T to reconvert these axions into photons. The magnet is able to follow the Sun for about 3 hours per day. Three different X-Ray detectors are mounted on its ends to detect photons from axion-to-photon conversion: a Time Projection Chamber (TPC), a MICROMEGAS (MICROMEsh GAseous Structure) and a Charge Coupled Device (CCD). For the CCD an X-ray focusing device is used to improve the signal-to-background ratio significantly. With the completion of CAST'S first phase, the current limits on the coupling constant gaγ for axion masses up to 0.02 eV have been improved. In its second phase, CAST extends the axion mass range by filling the magnet with a buffer gas. Masses up to about 0.4 eV have already been covered and thus the experiment is entering the regions favored by axion models. This paper will present the status of CAST'S second phase.

  10. A Solar Axion Search Using a Decommissioned LHC Test Magnet

    CERN Multimedia

    Raffelt, G; Geralis, T; Lozza, V; Christensen, F E; Jakobsen, A C; Neff, S H; Dafni, T; Carmona martinez, J M; Giomataris, I; Krcmar, M; Vafeiadis, T; Bayirli, A; Luzon marco, G M; Lakic, B; Solanki, S K; Ozbey, A; Davenport, M; Funk, W; Desch, K K; Laurent, J; Villar, J A; Jakovcic, K; Eleftheriadis, C; Cantatore, G; Diago ortega, A; Gracia garza, J; Ortega ruiz, I; Papaevangelou, T; Zioutas, K; Gardikiotis, A; Hasinoff, M D; Hoffmann, D; Iguaz gutierrez, F J; Castel pablo, J F; Gninenko, S; Ferrer ribas, E; Liolios, A; Anastasopoulos, V; Kaminski, J; Garcia irastorza, I; Ruiz choliz, E; Krieger, C; Lutz, G; Fanourakis, G; Ruz armendariz, J; Vogel, J K; Pivovaroff, M J

    2002-01-01

    Previous solar axion searches have been carried out in Brookhaven (1990) and in Tokyo (2000- ), tracking the Sun with a dipole magnet. QCD inspired axions should be produced after the Big Bang, being thus candidates for the dark matter. The Sun is a very useful source of weakly interacting particles for fundamental research. Axions can be produced also in the Sun's core through the scattering of thermal photons in the Coulomb field of electric charges (Primakoff effect). In a transverse magnetic field the Primakoff effect can work in reverse, coherently converting the solar axions or other axion-like particles (ALPS) back into X-ray photons in the keV range. The conversion efficiency increases with $(B⋅L)^2$. In the CAST experiment an LHC prototype dipole magnet (B = 9 T and L = 10 m) with straight beam pipes provides a conversion efficiency exceeding that of the two earlier solar axion telescopes by almost a factor of 100. This magnet is mounted on a moving platform and coupled to both gas filled and soli...

  11. A decommissioned LHC model magnet as an axion telescope

    International Nuclear Information System (INIS)

    The 8.4 T, 10 m long transverse magnetic field of a twin aperture LHC bending magnet can be utilized as a macroscopic coherent solar axion-to-photon converter. Numerical calculations show that the integrated time of alignment with the Sun would be 33 days/yr with the magnet on a tracking table capable of ±5 deg. in the vertical direction and ±40 deg. in the horizontal direction. The existing lower bound on the axion-to-photon coupling constant can be improved by a factor between 30 and 100 in 3 yr, i.e., gaγγ -11 GeV-1 for axion masses < or approx. 1 eV. This value falls within the existing open axion mass window. The same set-up can simultaneously search for low- and high-energy celestial axions, or axion-like particles, scanning the sky as the Earth rotates and orbits the Sun

  12. An application of space technology to the terrestrial search for axions The X-ray mirror telescope at CAST

    CERN Document Server

    Lutz, Gerhard; Englhauser, J; Hartmann, R; Kang, D; Kotthaus, R; Kuster, M; Serber, W; Strüder, L

    2004-01-01

    An X-ray mirror telescope consisting of a Wolter I type mirror assembly as used in X-ray astronomy and a new type X-ray CCD has been added to the CERN Axion Solar Telescope experiment. It will strongly improve the sensitivity in the search for axions, a so far elusive particle. The axion is predicted in order to explain the observed CP conservation in strong interaction which is not expected within the generally accepted "standard model". Construction and performance of the X-ray telescope are described. An improvement by two orders of magnitude in the signal over background S/B event ratio is estimated.

  13. New solar axion search in CAST with $^4$He filling

    CERN Document Server

    Arik, M; Barth, K; Belov, A; Brauninger, H; Bremer, J; Burwitz, V; Cantatore, G; Carmona, J M; Cetin, S A; Collar, J I; Da Riva, E; Dafni, T; Davenport, M; Dermenev, A; Eleftheriadis, C; Elias, N; Fanourakis, G; Ferrer-Ribas, E; Galan, J; Garcia, J A; Gardikiotis, A.; Garza, J G; Gazis, E N; Geralis, T; Georgiopoulou, E; Giomataris, I; Gninenko, S; Marzoa, M Gomez; Hasinoff, M D; Hoffmann, D H H; Iguaz, F J; Irastorza, I G; Jacoby, J; K.Jakovcic; Karuza, M; Kavuk, M; Krcmar, M; Kuster, M; Lakic, B; Laurent, J M; Liolios, A; Ljubicic, A; Luzon, G; Neff, S; Niinikoski, T; Nordt, A; Ortega, I; Papaevangelou, T; Pivovaroff, M .J; Raffelt, G; Rodriguez, A; Rosu, M; Ruz, J; Savvidis, I; Shilon, I; Solanki, S K; Stewart, L; Tomas, A; Vafeiadis, T; Villar, J; Vogel, J K; Yildiz, S C; Zioutas, K

    2015-01-01

    The CERN Axion Solar Telescope (CAST) searches for $a\\to\\gamma$ conversion in the 9 T magnetic field of a refurbished LHC test magnet that can be directed toward the Sun. Two parallel magnet bores can be filled with helium of adjustable pressure to match the X-ray refractive mass $m_\\gamma$ to the axion search mass $m_a$. After the vacuum phase (2003--2004), which is optimal for $m_a\\lesssim0.02$ eV, we used $^4$He in 2005--2007 to cover the mass range of 0.02--0.39 eV and $^3$He in 2009--2011 to scan from 0.39--1.17 eV. After improving the detectors and shielding, we returned to $^4$He in 2012 to investigate a narrow $m_a$ range around 0.2 eV ("candidate setting" of our earlier search) and 0.39--0.42 eV, the upper axion mass range reachable with $^4$He, to "cross the axion line" for the KSVZ model. We have improved the limit on the axion-photon coupling to $g_{a\\gamma}< 1.47\\times10^{-10} {\\rm GeV}^{-1}$ (95% C.L.), depending on the pressure settings. Since 2013, we have returned to vacuum and aim for a s...

  14. Solar Axion search with Micromegas detectors in the CAST Experiment with $^{3}$He as buffer gas

    CERN Document Server

    Garcia Pascual, Juan Antonio

    2015-01-01

    Axions are well motivated particles proposed in an extension of the Standard Model (SM) as a solution to the CP problem in strong interactions. On the other hand, there is the category of axion-like particles (ALPs) which appear in diverse extensions of the SM and share the same phenomenology of the axion. Axions and ALPs are hypothetical neutral particles that interact weakly with matter, being candidates to solve the Dark Matter problem. CAST, the CERN Axion Solar Telescope is looking for solar axions since 2003. CAST exploit the helioscope technique using a decommissioned LHC dipole magnet in which solar axions could be reconverted into photons. The magnet is mounted on a movable platform that allows tracking the Sun $\\sim$1.5 hours during sunset and during sunrise. The axion signal would be an excess of X-rays in the detectors located at the magnet bore ends and thus low background detectors are mandatory. Three of the four detectors operating at CAST are of the Micromegas type. The analysis of the data o...

  15. Search for low Energy solar Axions with CAST

    CERN Document Server

    Arik, E; Autiero, D; Barth, K; Belov, A; Beltrán, B; Borghi, S; Boydag, F S; Bräuninger, H; Cantatore, G; Carmona, J M; Cebrián, S; Cetin, S A; Collar, J I; Dafni, T; Davenport, M; Di Lella, L; Dogan, O B; Eleftheriadis, C; Elias, N; Fanourakis, G K; Ferrer-Ribas, E; Fischer, H; Franz, J; Galán, J; Gazis, E; Geralis, T; Giomataris, Ioanis; Gninenko, S; Gómez, H; Hasinoff, M; Heinsius, F H; Hikmet, I; Hoffmann, D H H; Irastorza, I G; Jacoby, J; Jakovicic, K; Kang, D; Karageorgopoulou, T; Karuza, M; Königsmann, K C; Kotthaus, R; Krcmar, M; Kousouris, K; Kuster, M; Lakic, B; Lasseur, C; Liolios, A; Ljubicic, A; Lozza, V; Lutz, G; Luzón, G; Miller, D; Morales, A; Morales, J; Niinikoski, T; Nordt, A; Ortiz, A; Papaevangelou, T; Pivovaroff, M; Placci, A; Raiteri, G; Raffelt, G; Riege, H; Rodríguez, A; Ruz, J; Savvidis, I; Semertzidis, Y; Serpico, Pasquale Dario; Solanki, S K; Soufli, R; Stewart, L; Tsagri, M; Van Bibber, K; Villar, J; Vogel, J; Walckiers, L; Zioutas, K

    2008-01-01

    We have started the development of a detector system, sensitive to single photons in the eV energy range, to be suitably coupled to one of the CAST magnet ports. This system should open to CAST a window on possible detection of low energy Axion Like Particles emitted by the sun. Preliminary tests have involved a cooled photomultiplier tube coupled to the CAST magnet via a Galileian telescope and a switched 40 m long optical fiber. This system has reached the limit background level of the detector alone in ideal conditions, and two solar tracking runs have been performed with it at CAST. Such a measurement has never been done before with an axion helioscope. We will present results from these runs and briefly discuss future detector developments.

  16. Results and perspectives of the solar axion search with the CAST experiment

    CERN Document Server

    Ferrer-Ribas, E; Aune, S; Barth, K; Belov, A; Borghi, S; Bräuninger, H; Cantatore, G; Carmona, J M; Cetin, S A; Collar, J I; Dafni, T; Davenport, M; Eleftheriadis, C; Elias, N; Ezer, C; Fanourakis, G; Friedrich, P; Galán, J; García, J A; Gardikiotis, A; Gazis, E N; Geralis, T; Giomataris, I; Gninenko, S; Gómez, H; Gruber, E; Guthörl, T; Hartmann, R; Haug, F; Hasinoff, M D; Hoffmann, D H H; Iguaz, F J; Irastorza, I G; Jacoby, J; Jakov\\vcić, K; Karuza, M; Königsmann, K; Kotthaus, R; Krčmar, M; Kuster, M; Lakić, B; Laurent, J M; Liolios, A; Ljubičić, A; Lozza, V; Lutz, G; Luzón, G; Morales, J; Niinikoski, T; Nordt, A; Papaevangelou, T; Pivovaroff, M J; Raffelt, G; Rashba, T; Riege, H; Rodríguez, A; Rosu, M; Ruz, J; Savvidis, I; Silva, P S; Solanki, S K; Stewart, L; Tomás, A; Tsagri, M; van Bibber, K; Vafeiadis, T; Villar, J; Vogel, J K; Yildiz, S C; Zioutas, K

    2012-01-01

    The status of the solar axion search with the CERN Axion Solar Telescope (CAST) will be presented. Recent results obtained by the use of $^3$He as a buffer gas has allowed us to extend our sensitivity to higher axion masses than our previous measurements with $^4$He. With about 1 h of data taking at each of 252 different pressure settings we have scanned the axion mass range 0.39 eV$ \\le m_{a} \\le $ 0.64 eV. From the absence of an excess of x rays when the magnet was pointing to the Sun we set a typical upper limit on the axion-photon coupling of g$_{a\\gamma} \\le 2.3\\times 10^{-10}$ GeV$^{-1}$ at 95% C.L., the exact value depending on the pressure setting. CAST published results represent the best experimental limit on the photon couplings to axions and other similar exotic particles dubbed WISPs (Weakly Interacting Slim Particles) in the considered mass range and for the first time the limit enters the region favored by QCD axion models. Preliminary sensitivities for axion masses up to 1.16 eV will also be s...

  17. CAST search for sub-eV mass solar axions with $^{3}$He buffer gas

    CERN Document Server

    Aune, S; Belov, A; Borghi, S; Brauninger, H; Cantatore, G; Carmona, J M; Cetin, S A; Collar, J I; Dafni, T; Davenport, M; Eleftheriadis, C; Elias, N; Ezer, C; Fanourakis, G; Ferrer-Ribas, E; Friedrich, P; Galan, J; Garcia, J A; Gardikiotis, A; Gazis, E N; Geralis, T; Giomataris, I; Gninenko, S; Gomez, H; Gruber, E; Guthorl, T; Hartmann, R; Haug, F; Hasinoff, M D; Hoffmann, D H H; Iguaz, F J; Irastorza, I G; Jacoby, J; Jakovcic, K; Karuza, M; Konigsmann, K; Kotthaus, R; Krcmar, M; Kuster, M; Lakic, B; Laurent, J M; Liolios, A; Ljubicic, A; Lozza, V; Lutz, G; Luzon, G; Morales, J; Niinikoski, T; Nordt, A; Papaevangelou, T; Pivovaroff, M J; Raffelt, G; Rashba, T; Riege, H; Rodriguez, A; Rosu, M; Ruz, J; Savvidis, I; Silva, P S; Solanki, S.K; Stewart, L; Tomas, A; Tsagri, M; van Bibber, K; Vafeiadis, T; Villar, J A; Vogel, J K; Yildiz, S C; Zioutas, K

    2011-01-01

    The CERN Axion Solar Telescope (CAST) has extended its search for solar axions by using 3He as a buffer gas. At T=1.8 K this allows for larger pressure settings and hence sensitivity to higher axion masses than our previous measurements with 4He. With about 1 h of data taking at each of 252 different pressure settings we have scanned the axion mass range 0.39 eV < m_a < 0.64 eV. From the absence of excess X-rays when the magnet was pointing to the Sun we set a typical upper limit on the axion-photon coupling of g_ag < 2.3 x 10^{-10} GeV^{-1} at 95% CL, the exact value depending on the pressure setting. KSVZ axions are excluded at the upper end of our mass range, the first time ever for any solar axion search. In future we will extend our search to m_a < 1.15 eV, comfortably overlapping with cosmological hot dark matter bounds.

  18. Probing the eV-Mass Range for Solar Axions with the CAST Experiment

    CERN Document Server

    VOGEL, Julia

    2009-01-01

    The CERN Axion Solar Telescope (CAST) is searching for solar axions, which could be produced in the core of the Sun via the so-called Primakoff effect. For this purpose, CAST uses a decommissioned LHC prototype magnet. In its magnetic field of 9 Tesla, axions could be reconverted into X-ray photons. The magnet is mounted on a structure built to follow the Sun during sunrise and sunset for a total of about 3 hours per day. The analysis of the data acquired during the first phase of the experiment with vacuum in the magnetic field region yielded the most restrictive experimental upper limit on the axion-to-photon coupling constant for axion masses up to about 0.02 eV. In order to extend the sensitivity of the experiment to a wider mass range, the CAST experiment continued its search for axions with helium in the magnet bores. In this way it is possible to restore coherence for larger masses. Changing the pressure of the helium gas enables the experiment to scan different axion masses. In the first part of this ...

  19. Solar axion experiments using coherent Primakoff conversion in single crystals

    International Nuclear Information System (INIS)

    The results of a 1.94 kg · y pilot search for solar axions with an ultralow background Ge detector are reviewed. The detection method is based on Bragg-coherent Primakoff conversion of axions into photons when the momentum vectors of the axion and photon satisfy the Bragg condition. The theory of the experiment are presented for Ge and Te02 crystals. Future prospects of large volume experiments are discussed

  20. Probing the eV-mass range for solar axions with the CAST experiment

    International Nuclear Information System (INIS)

    The CERN Axion Solar Telescope (CAST) is searching for solar axions, which could be produced in the core of the Sun via the so-called Primakoff effect. For this purpose, CAST uses a decommissioned LHC prototype magnet. In its magnetic field of 9 Tesla axions could be reconverted into X-ray photons. The magnet is mounted on a structure built to follow the Sun during sunrise and sunset for a total of about 3 hours per day. The analysis of the data acquired during the first phase of the experiment with vacuum in the magnetic field region yielded the most restrictive experimental upper limit on the axion-to-photon coupling constant for axion masses up to about 0.02 eV. In order to extend the sensitivity of the experiment to a wider mass range, the CAST experiment continued its search for axions with helium in the magnet bores. In this way it is possible to restore coherence for larger masses. Changing the pressure of the helium gas enables the experiment to scan different axion masses. In the first part of this second phase of CAST, helium-4 has been used and the axion mass region was extended up to 0.4 eV. Therefore the experiment enters the regions favored by axion models. In CAST's ongoing helium-3 phase the studied mass range is now further extended. We will present the final results of CAST's helium-4 phase. Furthermore the latest upgrades of the experiments will be shown and an outlook on CAST's status and prospects will be given. (author)

  1. A Micromegas-based low-background x-ray detector coupled to a slumped-glass telescope for axion research

    DEFF Research Database (Denmark)

    Aznar, F.; Castel, J.; Christensen, F. E.;

    2015-01-01

    -approximation Wolter I x-ray telescope (XRT) assembled from thermally-formed (or "slumped") glass substrates deposited with multilayer coatings. The system has been conceived as a technological pathfinder for the future International Axion Observatory (IAXO), as it combines two of the techniques (optic and detector......) proposed in the conceptual design of the project. It is innovative for two reasons: it is the first time an x-ray optic has been designed and fabricated specifically for axion research, and the first time a Micromegas detector has been operated with an x-ray optic. The line has been installed at one end of...... the CERN Axion Solar Telescope (CAST) magnet and is currently looking for solar axions. The combination of the XRT and Micromegas detector provides the best signal-to-noise ratio obtained so far by any detection system of the CAST experiment with a background rate of 5.4×10−3 counts per hour in the...

  2. Probing the eV-Mass Range for Solar Axions with CAST

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, J K; Pivovaroff, M J; Soufli, R; van Bibber, K; CAST, C

    2010-11-11

    The CERN Axion Solar Telescope (CAST) is searching for solar axions which could be produced in the core of the Sun via the so-called Primakoff effect. Not only would these hypothetical particles solve the strong CP problem, but they are also one of the favored candidates for dark matter. In order to look for axions originating from the Sun, CAST uses a decommissioned LHC prototype magnet. In its 10 m long magnetic field region of 9 Tesla, axions could be reconverted into X-ray photons. Different X-ray detectors are installed on both ends of the magnet, which is mounted on a structure built to follow the Sun during sunrise and sunset for a total of about 3 hours per day. The analysis of the data acquired during the first phase of the experiment with vacuum in the magnetic field region yielded the most restrictive experimental upper limit on the axion-to-photon coupling constant for axion masses up to about 0.02 eV. In order to extend the sensitivity of the experiment to a wider mass range, the CAST experiment continues its search for axions with helium in the magnet bores. In this way it is possible to restore coherence of conversion for larger masses. Changing the pressure of the helium gas enables the experiment to scan different axion masses in the range of up to about 1.2 eV. Especially at high pressures, a precise knowledge of the gas density distribution is crucial to obtain accurate results. In the first part of this second phase of CAST, {sup 4}He was used and the axion mass region was extended up to 0.39 eV, a part of phase space favored by axion models. In CAST's ongoing {sup 3}He phase the studied mass range is now being extended further. In this contribution the final results of CAST's {sup 4}He phase will be presented and the current status of the {sup 3}He run will be given. This includes latest results as well as prospects of future axion experiments.

  3. Design for a practical laboratory detector for solar axions

    International Nuclear Information System (INIS)

    We present a practical design for a detector sensitive to axions and other light particles with a two-photon interaction vertex. Such particles would be produced in the solar interior by Primakoff conversion of blackbody photons and could be detected by their reconversion into x rays (average energy about 4 keV) in a strong laboratory magnetic field. An existing large superconducting magnet would be suitable for this purpose. The transition rate is enhanced by filling the conversion region with a buffer gas (H2 or He). This induces an effective photon mass (plasma frequency) which can be adjusted to equal the axion mass being searched for. Axion-photon conversion is then coherent throughout the detector volume for all axion energies. Axions with mass in the range 0.1 eVapprox. < m/sub a/approx. <5 eV can be detected using gas pressures of 0.1--300 atm. Axions with the standard coupling strength to photons would give counting rates of 10/sup -5/--10 sec/sup -1/ over this mass range. The search would definitively test one of the only two regions of axion parameters not excluded by astrophysical constraints

  4. Searching for Solar Axions in the eV-MassRegion with the CCD Detector at CAST

    CERN Document Server

    Vogel, J K

    2009-01-01

    The CERN Axion Solar Telescope (CAST) is searching for solar axions, which could be produced in the core of the Sun via the so-called Primakoff effect. For this purpose, CAST uses a decommissioned LHC prototype magnet. In its magnetic field of 9 Tesla axions could be reconverted into X-ray photons. The magnet is mounted on a structure built to follow the Sun during sunrise and sunset for a total of about 3 hours per day. The analysis of the data acquired during the first phase of the experiment with vacuum in the magnetic field region yielded the best experimental upper limit on the axion-to-photon coupling constant for axion masses up to about 0.02 eV. In order to extend the sensitivity of the experiment to a wider mass range, the CAST experiment continued its search for axions with helium in the magnet bores. In this way it is possible to restore coherence for larger masses. Changing the pressure of the helium gas enables the experiment to scan different axion masses. In the first part of this second phase ...

  5. Prospects for solar axion searches with crystals via Bragg scattering

    International Nuclear Information System (INIS)

    A calculation of the expected signal due to Primakov coherent conversion of solar axions into photons via Bragg scattering in several solid-state detectors is presented and compared with present and future experimental sensitivities. The axion window ma > or approx. 0.03 eV (not accessible at present by other techniques) could be explored in the foreseeable future with crystal detectors to constrain the axion-photon coupling constant gaγγ below the latest bounds coming from helioseismology. On the contrary a positive signal in the sensitivity region of such devices would imply revisiting other more stringent astrophysical limits derived for the same range of the axion mass. The application of this technique to the COSME germanium detector which is taking data at the Canfranc Underground Laboratory leads to a 95% C.L. limit gaγγ ≤ 2.8 x 10-9 GeV-1

  6. Axions

    International Nuclear Information System (INIS)

    The Peccei-Quinn symmetry is a possible solution to the strong C.P. violation problem resulting from instantons contributions. It is the objective of this dissertation to study models which incorporate the Paccei-Ouinn symmetry as well as its consequences, for instance, the exiatence of a Goldstone pseudoboson named axion and the appearence of topologically satble structures generated at the spontaneous breakdown of the Peccei-Quinn symmetry. We also study the interchanged between axion models and Cosmology, particularly the influence of axions on the process of galsxy formation. (author)

  7. Axion experiment makes its debut

    CERN Multimedia

    Dumé, Belle

    2004-01-01

    An experiment built from components recycled from other experiments has put new limits on the properties of particles that might be the "dark matter" that makes up about 25% of the universe. The CERN Axion Solar telescope (CAST) was built to search for exotic particles called axions that might be produced inside the sun (1 page)

  8. Search for Solar Axions with the CDMS-II Experiment

    CERN Document Server

    Bruch, T

    2008-01-01

    The CDMS-II experiment operates 19 germanium detectors with a mass of 250g each in a very low background environment. Originally designed for the search for Dark Matter the experiment can also detect solar axions by Primakoff conversion to photons. The Bragg condition for X-ray momentum transfer in a crystal allows for coherent amplification of the Primakoff process. Since the orientation of the crystal lattice with respect to the Sun changes with daytime an unique pattern in time and energy of solar axion conversions is expected. The low background ~1.5 counts/kg/day/keV and knowledge of the exact orientation of all three crystal axes with respect to the Sun make the CDMS-II experiment very sensitive to solar axions. In contrast to helioscopes, the high mass region < 1 keV can also be probed effectively. The alternating orientations of the individual crystals in the experimental setup provide different patterns of solar axion conversion, making a false positive result extremely unlikely. The result of an ...

  9. New Vacuum Solar Telescope

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    With its pure aperture up to 985mm, the New Vacuum Solar Telescope of China (NVST) has become the world's biggest vacuum solar telescope. The main science task of NVST is the high-resolution observation of photosphere and chromosphere including their fine structure of magnetic field on the sun. The NVST was equipped with many new technologies and powerful instruments, such as an adaptive optical system, a polarization analyzer, two vertical spectrographs, a high-resolution image system and a very narrow Ha filter (0.125A).

  10. Contribution to the search for solar axions in the CAST experiment

    CERN Document Server

    Vafeiadis, Theodoros; Savvidis, Ilias; Liolios, Tassos; Eleftheriadis, Christos

    The CERN Axion Solar Telescope (CAST) is an implementation of the axion helioscope with the highest sensitivity to date. In the present thesis the results of the analysis of one of the Micromegas detectors in CAST (sunrise side) for the 2009 and 2010 data taking periods are presented. A new detector lab has been realized at CERN (162 S-065) with a variable energy calibration system based on an X-ray beam line built at the Max-Planck-Institut für extraterrestrische Physik/Garching (MPE). The purpose of this work is to calibrate for the first time the present and future CAST detectors, in a number of energies and test the efficiency of the software selection criteria.The results of the measurements in the lab were used in the analysis of the data acquired in 2009 and 2010 with the sunrise Micromegas detector of CAST.\

  11. Progress in Space Solar Telescope

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In this paper we will summarize the progress in the development of the Chinese Space Solar Telescope (SST) during the past few years. The main scientific objective of SST is to observe the fundamental structure of solar magnetic field with its 1-m optical telescope. The success of 1-m Swedish Solar Telescope and Hinode underscores the importance of this 1-m space telescope. In addition, some key technical problems have been solved.

  12. Search for 14.4-KeV Solar Axions Emitted in the M1-Transition of Fe-57 Nuclei with CAST

    Energy Technology Data Exchange (ETDEWEB)

    Andriamonje, S.; Aune, S.; /DAPNIA, Saclay; Autiero, D.; /CERN /Lyon, IPN; Barth, K.; /CERN; Belov, A.; /Moscow, INR; Beltran, B.; /Zaragoza U. /Queen' s U., Kingston; Brauninger, H.; /Garching, Max Planck Inst., MPE; Carmona, J.M.; Cebrian, S.; /Zaragoza U.; Collar, J.I.; /Chicago U., EFI /Chicago U., KICP; Dafni, T.; /DAPNIA, Saclay /Darmstadt, Tech. Hochsch. /Zaragoza U.; Davenport, M.; /CERN; Di Lella, L.; /CERN /Pisa, Scuola Normale Superiore; Eleftheriadis, C.; /Aristotle U., Thessaloniki; Englhauser, J.; /Garching, Max Planck Inst., MPE; Fanourakis, G.; /Democritos Nucl. Res. Ctr.; Ferrer-Ribas, E.; /DAPNIA, Saclay; Fischer, H.; Franz, J.; /Freiburg U.; Friedrich, P.; /Garching, Max Planck Inst., MPE; Geralis, T.; /Democritos Nucl. Res. Ctr. /DAPNIA, Saclay /Moscow, INR /Zaragoza U. /British Columbia U. /Freiburg U. /Darmstadt, Tech. Hochsch. /DAPNIA, Saclay /Zaragoza U. /Frankfurt U. /Boskovic Inst., Zagreb /Freiburg U. /Munich, Max Planck Inst. /Boskovic Inst., Zagreb /Democritos Nucl. Res. Ctr. /Darmstadt, Tech. Hochsch. /Garching, Max Planck Inst., MPE /Boskovic Inst., Zagreb /CERN /Aristotle U., Thessaloniki /Boskovic Inst., Zagreb /Munich, Max Planck Inst. /Zaragoza U. /Chicago U., EFI /Chicago U., KICP /Stanford U., Phys. Dept. /SLAC /Zaragoza U. /CERN /DAPNIA, Saclay /CERN /Munich, Max Planck Inst. /Darmstadt, Tech. Hochsch. /Zaragoza U. /Aristotle U., Thessaloniki /Patras U. /Brookhaven /CERN /Munich, Max Planck Inst. /CERN /Chicago U., EFI /Chicago U., KICP /Zaragoza U. /Freiburg U. /CERN /CERN /Patras U.

    2011-12-02

    We have searched for 14.4 keV solar axions or more general axion-like particles (ALPs), that may be emitted in the M1 nuclear transition of 57Fe, by using the axion-to-photon conversion in the CERN Axion Solar Telescope (CAST) with evacuated magnet bores (Phase I). From the absence of excess of the monoenergetic X-rays when the magnet was pointing to the Sun, we set model-independent constraints on the coupling constants of pseudoscalar particles that couple to two photons and to a nucleon g{sub ay}|-1.19g{sub aN}{sup 0}+g{sub aN}{sup 3}| < 1.36 x 10{sup -16} GeV{sup -1} for ma < 0.03 eV at the 95% confidence level.

  13. Search for 14.4 keV solar axions emitted in the M1-transition of $^{57}$Fe nuclei with CAST

    CERN Document Server

    Andriamonje, S; Autiero, D; Barth, K; Belov, A; Beltrán, B; Bräuninger, H; Carmona, J M; Cebrián, S; Collar, J I; Dafni, T; Davenport, M; Di Lella, L; Eleftheriadis, C; Englhauser, J; Fanourakis, G K; Ferrer-Ribas, E; Fischer, H; Franz, J; Friedrich, P; Geralis, T; Giomataris, Yu; Gninenko, S; Gómez, H; Hasinoff, M; Heinsius, F H; Hoffmann, D H H; Irastorza, I G; Jacoby, J; Jakovčić, K; Kang, D; Königsmann, K C; Kotthaus, R; Krčmar, M; Kousouris, K; Kuster, M; Lakić, B; Lasseur, C; Liolios, A; Ljubičić, A; Lutz, G; Luzón, G; Miller, D; Morales, J; Ortiz, A; Papaevangelou, T; Placci, A; Raffelt, G; Riege, H; Rodríguez, A; Ruz, J; Savvidis, I; Semertzidis, Y; Serpico, P; Stewart, L; Vieira, J; Villar, J; Vogel, J; Walckiers, L; Zioutas, K

    2009-01-01

    We have searched for 14.4 keV solar axions or more general axion-like particles (ALPs), that may be emitted in the M1 nuclear transition of 57Fe, by using the axion-to-photon conversion in the CERN Axion Solar Telescope (CAST) with evacuated magnet bores (Phase I). From the absence of excess of the monoenergetic X-rays when the magnet was pointing to the Sun, we set model-independent constraints on the coupling constants of pseudoscalar particles that couple to two photons and to a nucleon g_{a\\gamma} |-1.19 g_{aN}^{0}+g_{aN}^{3}|<1.36\\times 10^{-16} GeV^{-1} for m_{a}<0.03 eV at the 95% confidence level.

  14. Magnetic Scope Angles for Axions

    CERN Multimedia

    Seife, Charles

    2005-01-01

    After 2 years of staring at the sun, an unconventional "telescope" made from a leftover magnet has returned its first results. Although it hasn't yet found the quarry it was designed to spot - a particle that might or might not exist physicists say the CERN Axion Solar Telescope (CAST) is beginning to glimpse uncharted territory

  15. Experimental Search for Solar Axions via Coherent Primakoff Conversion in a Germanium Spectrometer

    CERN Document Server

    Avignone, F T; Brodzinski, R; Collar, J I; Creswick, R J; Di Gregorio, D E; Farach, H A; Gattone, A O; Guérard, C K; Hasenbalg, F; Huck, H; Miley, H S; Morales, A; Morales, J; Nussinov, S; De Solorzano, A O; Reeves, J H; Villar, J; Zioutas, Konstantin

    1998-01-01

    Results are reported of an experimental search for the unique, rapidly varying temporal pattern of solar axions coherently converting into photons via the Primakoff effect in a single crystal germanium detector. This conversion is predicted when axions are incident at a Bragg angle with a crystalline plane. The analysis of approximately 1.94 kg.yr of data from the 1 kg DEMOS detector in Sierra Grande, Argentina, yields a new laboratory bound on axion-photon coupling of $g_{a\\gamma \\gamma} < 2.7\\cdot 10^{-9}$ GeV$^{-1}$, independent of axion mass up to ~ 1 keV.

  16. Experimental Search for Solar Axions via Coherent Primakoff Conversion in a Germanium Spectrometer

    International Nuclear Information System (INIS)

    Results are reported of an experimental search for the unique, rapidly varying temporal pattern of solar axions coherently converting into photons via the Primakoff effect in a single crystal germanium detector when axions are incident at a Bragg angle with a crystalline plane. The analysis of 1.94kgyr of data from the 1kg DEMOS detector in Sierra Grande, Argentina, yields a new laboratory bound by an axion-photon coupling of gaγγ-9 GeV-1 , independent of axion mass up to ∼1 keV . copyright 1998 The American Physical Society

  17. Search for solar axions with CsI(Tl) crystal detectors

    CERN Document Server

    Yoon, Y S; Bhang, H; Choi, J H; Choi, S; Hahn, I S; Jeon, E J; Joo, H W; Kang, W G; Kim, B H; Kim, G B; Kim, H J; Kim, K W; Kim, S C; Kim, S K; Kim, Y D; Kim, Y H; Lee, H S; Lee, J H; Lee, J K; Lee, S J; Leonard, D S; Li, J; Myung, S S; Olsen, S L; So, J H

    2016-01-01

    The results of a search for solar axions from the Korea Invisible Mass Search (KIMS) experiment at the Yangyang Underground Laboratory are presented. Low-energy electron-recoil events would be produced by conversion of solar axions into electrons via the axio-electric effect in CsI(Tl) crystals. Using data from an exposure of 34,596 $\\rm kg \\cdot days$, we set a 90 \\% confidence level upper limit on the axion-electron coupling, $g_{ae}$, of $1.39 \\times 10^{-11}$ for an axion mass less than 1 keV/$\\rm c^2$. This limit is lower than the indirect solar neutrino bound, and fully excludes QCD axions heavier than 0.48 eV/$\\rm c^2$ and 140.9 eV/$\\rm c^2$ for the DFSZ and KSVZ models respectively.

  18. The Chinese Giant Solar Telescope

    Science.gov (United States)

    Liu, Zhong; Deng, Yuanyong; Ji, Haisheng

    2014-01-01

    Chinese Giant Solar Telescope is the next generation ground-based solar telescope. The main science task of this telescope is to observe the ultra fine structures of the solar magnetic field and dynamic field. Due to the advantages in polarization detection and thermal controlling with a symmetrical circular system, the current design of CGST is a 6~8 meter circular symmetrical telescope. The results of simulations and analysis showed that the current design could meet the demands of most science cases not only in infrared bands but also in near infrared bands and even in visible bands. The prominences and the filaments are very important science cases of CGST. The special technologies for prominence observation will be developed, including the day time laser guide star and MCAO. CGST is proposed by all solar observatories and several institutes and universities in China. It is supported by CAS and NSFC (National Natural Science Foundation of China) as a long term astronomical project.

  19. Search for Solar Axions Produced in the $p + d \\rightarrow\\rm{^3He}+ A$ Reaction

    CERN Document Server

    Derbin, A V; Muratova, V N; 10.3103/S106287381006016X

    2010-01-01

    A search for the axioelectric absorption of 5.5-MeV solar axions produced in the $p+d\\rightarrow \\rm{^3He}+\\gamma(5.5 \\rm{MeV})$ reaction was performed with two BGO detectors placed inside a low-background setup. A model independent limit on axion-photon and axion-nucleon couplings was obtained: $|g_{Ae}\\times g_{AN}| \\leq 3.2\\times 10^{-9} (m_A=0)$. Constraints on the axion-electron coupling constant were obtained for axions with masses in the $(0.1-1.0)$ MeV range: $g_{Ae}\\leq (1.8-9.0)\\times 10^{-7}$. The solar positron flux from $A\\rightarrow e^-+e^+$ decay was determined for axions with masses $m_A > 2m_e$. Using the existing experimental data on the interplanetary positron flux, a new constraint on the axion-electron coupling constant for axions with masses in the $(1.2-5.4)$ MeV range was obtained: $g_{Ae} \\leq (1-5)\\times 10^{-17}$.

  20. A Micromegas-based low-background x-ray detector coupled to a slumped-glass telescope for axion research

    CERN Document Server

    Aznar, F; Christensen, F E; Dafni, T; Decker, T A; Ferrer-Ribas, E; Garcia, J A; Giomataris, I; Gracia, J G; Hailey, C J; Hill, R M; Iguaz, F J; Irastorza, I G; Jakobsen, A C; Luzon, G; Mirallas, H; Papaevangelou, T; Pivovaroff, M J; Ruz, J; Vafeiadis, T; Vogel, J K

    2015-01-01

    We report on the design, construction and operation of a low background x-ray detection line composed of a shielded Micromegas (micromesh gaseous structure) detector of the microbulk technique. The detector is made from radiopure materials and is placed at the focal point of a $\\sim$~5 cm diameter, 1.3 m focal-length, cone-approximation Wolter I x-ray telescope (XRT) comprised of thermally-formed (or "slumped") glass substrates deposited with multilayer coatings. The system has been conceived as a technological pathfinder for the future International Axion Observatory (IAXO), as it combines two of the techniques (optic and detector) proposed in the conceptual design of the project. It is innovative for two reasons: it is the first time an x-ray optic has been designed and fabricated specifically for axion research, and the first time a Micromegas detector has been operated with an x-ray optic. The line has been installed at one end of the CERN Axion Solar Telescope (CAST) magnet and is currently looking for s...

  1. Searching for Solar Axions using the MAJORANA DEMONSTRATOR

    Science.gov (United States)

    O'Shaughnessy, Christopher; Majorana Collaboration

    2015-10-01

    The choice of P-Type Point Contact (PPC) detectors for the Majorana Demonstrator (MJD) was driven by the high energy resolution and superb pulse shape analysis capability of this technology. Due to its low-capacitance this technology also boasts good energy resolution even at low energy, at the keV scale or better. This opens up an ensemble of searches for new physics that can be pursued in parallel with the main goals of searching for neutrinoless double beta decay. Here I will discuss the efforts toward measuring crystal axes in the as-built detector units of MJD to improve sensitivity to the detection of solar axions. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, the Particle Astrophysics Program of the National Science Foundation, and the Sanford Underground Research Facility.

  2. Search for axioelectric effect of solar axions using BGO scintillating bolometer

    Energy Technology Data Exchange (ETDEWEB)

    Derbin, A.V.; Kayunov, A.S.; Muratova, V.N.; Semenov, D.A.; Unzhakov, E.V. [St. Petersburg Nuclear Physics Institute, Gatchina (Russian Federation); Gironi, L.; Biassoni, M.; Capelli, S.; Clemenza, M.; Ferri, E.; Giachero, A.; Gotti, C.; Maiano, C.; Maino, M.; Pavan, M.; Sisti, M. [INFN-Sezione di Milano Bicocca, Milano (Italy); Universita di Milano-Bicocca, Dipartimento di Fisica, Milano (Italy); Nagorny, S.S. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Gran Sasso Science Institute, INFN, L' Aquila, AQ (Italy); Pattavina, L.; Pirro, S. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Beeman, J.W. [Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Bellini, F. [INFN-Sezione di Roma, Rome (Italy); Universita di Roma La Sapienza, Dipartimento di Fisica, Rome (Italy); Drachnev, I.S. [St. Petersburg Nuclear Physics Institute, Gatchina (Russian Federation); Gran Sasso Science Institute, INFN, L' Aquila, AQ (Italy)

    2014-09-15

    A search for axioelectric absorption of solar axions produced in the p + d → {sup 3}He + γ(5.5 MeV) reaction has been performed with a BGO detector placed in a low-background setup. A model-independent limit on the combination of axion.nucleon and axion.electron coupling constants has been obtained: vertical stroke g{sub Ae} x g{sup 3}{sub AN} vertical stroke < 1.9 x 10{sup -10} for 90 % confidence level. The constraint of the axion.electron coupling constant has been obtained for hadronic axion with masses of (0.1.1) MeV: vertical stroke g{sub Ae} vertical stroke ≤ (0.96. 8.2) x 10{sup -8}. (orig.)

  3. Experimental Search for Solar Axions via Coherent Primakoff Conversion in a Germanium Spectrometer

    OpenAIRE

    Avignone, F. T.; Abriola, D.; Brodzinski, R. L.; J. I. Collar; Creswick, R.J.; DiGregorio, D. E.; Farach, H. A.; Gattone, A. O.; Guerard, C. K.; Hasenbalg, F.; Huck, H.; Miley, H. S.; Morales, A.; MORALES, J., CRUZ, D., DELGADO, P., LIZANA, M., LÓPEZ, V.; Nussinov, S.

    1997-01-01

    Results are reported of an experimental search for the unique, rapidly varying temporal pattern of solar axions coherently converting into photons via the Primakoff effect in a single crystal germanium detector. This conversion is predicted when axions are incident at a Bragg angle with a crystalline plane. The analysis of approximately 1.94 kg.yr of data from the 1 kg DEMOS detector in Sierra Grande, Argentina, yields a new laboratory bound on axion-photon coupling of $g_{a\\gamma \\gamma} < 2...

  4. Searches for axioelectric effect of solar axions with BGO-scintillator and BGO-bolometer detectors

    CERN Document Server

    Muratova, V N; Giorni, L; Nagorny, S S; Pattavina, L; Bakhlanov, S V; Beeman, J W; Bellini, F; Biassoni, M; Capelli, S; Clemenza, M; Dratchnev, I S; Ferri, E; Giachero, A; Gotti, C; Kayunov, A S; Maiano, C; Maino, M; Pavan, M; Pirro, S; Semenov, D A; Sisti, M; Unzhakov, E V

    2015-01-01

    A search for axioelectric absorption of 5.5 MeV solar axions produced in the $p + d \\rightarrow {^3\\rm{He}}+\\gamma~(5.5~ \\rm{MeV})$ reaction has been performed with a BGO detectors. A model-independent limit on the product of axion-nucleon $g_{AN}^3$ and axion-electron $g_{Ae}$ coupling constants has been obtained: $| g_{Ae}\\times g_{AN}^3|< 1.9\\times 10^{-10}$ for 90\\% C.L..

  5. Axions - Motivation, limits and searches

    OpenAIRE

    Raffelt, Georg G.

    2006-01-01

    The axion solution of the strong CP problem provides a number of possible windows to physics beyond the standard model, notably in the form of searches for solar axions and for galactic axion dark matter, but in a broader context also inspires searches for axion-like particles in pure laboratory experiments. We briefly review the motivation for axions, astrophysical limits, their possible cosmological role, and current searches for axions and axion-like particles.

  6. Search for solar axions the CAST experiment at CERN

    CERN Document Server

    Beltran, B; Arsov, V; Aune, S; Autiero, D; Avignone, F T; Barth, K; Belov, A; Bräuninger, H; Carmona, J M; Cebrián, S; Chesi, Enrico Guido; Collar, J I; Creswick, R; Dafni, T; Davenport, M; Dilella, L; Eleftheriadis, C; Englhauser, J; Fanourakis, G K; Farach, H; Ferrer, E; Fischer, H; Franz, J; Friedrich, P; Geralis, T; Giomataris, Ioanis; Gninenko, S; Goloubev, N; Hartmann, R; Hasinoff, M D; Heinsius, F H; Hoffmann, Dieter H H; Irastorza, I G; Jacoby, J; Kang, D; Königsmann, K C; Kotthaus, R; Krcmar, M; Kousouris, K; Kuster, M; Lakic, B; Lasseur, C; Liolios, A; Ljubici, A; Lutz, Gerhard; Luzón, G; Miller, D W; Morales, A; Morales, J; Mutterer, M; Nikolaidis, A; Ortiz, A; Papaevangelou, T; Placci, A; Raffelt, G; Ruz, J; Riege, H; Sarsa, M L; Savvidis, I; Serber, W; Serpico, Pasquale Dario; Semertzidis, Y K; Stewart, L; Vieira, J D; Villar, J; Walckiers, L; Zachariadou, K; Zioutas, Konstantin; Beltran, Berta

    2006-01-01

    Hypothetical axion-like particles with a two-photon interaction would be produced in the sun by the Primakoff process. In a laboratory magnetic field they would be transformed into X-rays with energies of a few keV. The CAST experiment at CERN is using a decommissioned LHC magnet as an axion helioscope in order to search for these axion-like particles. The analysis of the 2003 data has shown no signal above the background, thus implying an upper limit to the axion-photon coupling < 1.16*10^{-10} GeV^{-1} at 95% CL for m_{a} <~ 0.02 eV. The stable operation of the experiment during 2004 data taking allow us to anticipate that this value will be improved. At the end of 2005 we expect to start with the so-called second phase of CAST, when the magnet pipes will be filled with a buffer gas so that the axion-photon coherence will be extended. In this way we will be able to search for axions with masses up to 1 eV.

  7. Experimental probes of axions

    Energy Technology Data Exchange (ETDEWEB)

    Chou, Aaron S.; /Fermilab

    2009-10-01

    Experimental searches for axions or axion-like particles rely on semiclassical phenomena resulting from the postulated coupling of the axion to two photons. Sensitive probes of the extremely small coupling constant can be made by exploiting familiar, coherent electromagnetic laboratory techniques, including resonant enhancement of transitions using microwave and optical cavities, Bragg scattering, and coherent photon-axion oscillations. The axion beam may either be astrophysical in origin as in the case of dark matter axion searches and solar axion searches, or created in the laboratory from laser interactions with magnetic fields. This note is meant to be a sampling of recent experimental results.

  8. The Next Generation of Axion Helioscopes: The International Axion Observatory (IAXO)

    DEFF Research Database (Denmark)

    Vogel, J.K.; Armengaud, E.; Avignone, F.T.;

    2015-01-01

    The International Axion Observatory (IAXO) is a proposed 4th-generation axion helioscope with the primary physics research goal to search for solar axions via their Primakoff conversion into photons of 1 – 10 keV energies in a strong magnetic field. IAXO will achieve a sensitivity to the axion......-photon coupling gaγ down to a few ×10−12 GeV−1 for a wide range of axion masses up to ∼ 0.25eV. This is an improvement over the currently best (3rd generation) axion helioscope, the CERN Axion Solar Telescope (CAST), of about 5 orders of magnitude in signal strength, corresponding to a factor ∼ 20 in the axion...... photon coupling. IAXO's sensitivity relies on the construction of a large superconducting 8-coil toroidal magnet of 20 m length optimized for axion research. Each of the eight 60cm diameter magnet bores is equipped with x-ray optics focusing the signal photons into ∼ 0.2cm2 spots that are imaged by very...

  9. Search for solar axions emitted in the M1-transition of 7Li* with Borexino CTF

    International Nuclear Information System (INIS)

    Results of background measurements with a prototype of the Borexino detector were used to search for 478 keV solar axions emitted in the M1-transitions of 7Li*. The Compton conversion of axion to a photon A+e→e+γ, axioelectric effect A+e+Z→e+Z, decay of axion in two photons A→2γ and Primakoff conversion on nuclei A+Z→γ+Z are considered. The upper limit on constants of interaction of axion with electrons, photons and nucleons -gAegAN≤(1.0-2.4) x 10-10 at mA≤450 keV and gAγgAN≤5 x 10-9 GeV-1 at mA≤10 keV are obtained (90%c.l.). For heavy axions with mass at 100AAe-8 and gAγ-9-10-8 are obtained in assumption that gAN depends on mA as for KSVZ axion model. These limits are stronger than obtained in previous laboratory-based experiments using nuclear reactor and artificial radioactive sources. (orig.)

  10. Axions at the International Axion Observatory

    CERN Document Server

    Redondo, Javier

    2016-01-01

    QCD axions with meV mass can be behind some stellar cooling anomalies and form all or part of the cold dark matter of the universe. We discuss on a proposed experiment to discover the solar flux of meV mass axions: the International AXion Observatory: IAXO.

  11. Search for Solar Axions Produced in $p(d,\\rm{^3He})A$ Reaction with Borexino Detector

    OpenAIRE

    Bellini, G.; Benziger, J.; Bick, D.; Bonfini, G.; Bravo, D.; Avanzini, M.; Caccianiga, B.; Cadonati, L.; Calaprice, F.; Carraro, C.; Cavalcante, P.; Chavarria, A.(Kavli Institute, Enrico Fermi Institute, Dept. of Physics, University of Chicago, Chicago, IL, 60637, USA); D. D’Angelo; Davini, S.; Derbin, A.

    2012-01-01

    A search for 5.5-MeV solar axions produced in the $p+d\\rightarrow\\rm{^3He}+A (5.5 \\rm{MeV})$ reaction was performed using the Borexino detector. The Compton conversion of axions to photons, ${\\rm A}+e\\rightarrow e+\\gamma$; the axio-electric effect, ${\\rm A}+e+Z\\rightarrow e+Z$; the decay of axions into two photons, ${\\rm A}\\rightarrow2\\gamma$; and inverse Primakoff conversion on nuclei, ${\\rm A}+Z\\rightarrow\\gamma+Z$, are considered. Model independent limits on axion-electron ($g_{Ae}$), axio...

  12. Axion mechanism of the Sun luminosity and solar dynamo - geodynamo connection

    CERN Document Server

    Rusov, V D; Kudela, K; Mavrodiev, S Cht; Sharph, I V; Zelentsova, T N; Smolyar, V P; Merkotan, K K

    2010-01-01

    We show existence of strong negative correlation between the temporal varia-tions of magnetic field toroidal component of the solar tachocline (the bottom of convective zone) and the Earth magnetic field (Y-component). The possibility that hypothetical solar axions, which can transform into photons in external electric or magnetic fields (the inverse Primakoff effect), can be the instrument by which the magnetic field of convective zone of the Sun modulates the magnetic field of the Earth is considered. We propose the axion mechanism of Sun luminosity and "solar dynamo - geodynamo" connection, where an energy of solar axions emitted in M1 transition in 57Fe nuclei is modulated at first by the magnetic field of the solar tachocline zone (due to the inverse coherent Primakoff effect) and after that is resonance absorbed in the core of the Earth, thereby playing the role of an energy source and a modulator of the Earth magnetic field. Within the framework of this mechanism estimations of the strength of an axion...

  13. The X-ray Telescope of the CAST Experiment

    CERN Document Server

    Kotthaus, R; Friedrich, P; Hartmann, R; Kang, D; Kuster, M; Lutz, Gerhard; Strüder, L

    2005-01-01

    The CERN Axion Solar Telescope (CAST) searches for solar axions employing a 9 Tesla superconducting dipole magnet equipped with 3 independent detection systems for X-rays from axion-photon conversions inside the 10 m long magnetic field. Results of the first 6 months of data taking in 2003 imply a 95 % CL upper limit on the axion-photon coupling constant of 1.16x10(-10) GeV(-1) for axion masses < 0.02 eV. The most sensitive detector of CAST is a X-ray telescope consisting of a Wolter I type mirror system and a fully depleted pn-CCD as focal plane detector. Exploiting the full potential of background suppression by focussing X-rays emerging from the magnet bore, the axion sensitivity obtained with telescope data taken in 2004, for the first time in a controlled laboratory experiment, will supersede axion constraints derived from stellar energy loss arguments.

  14. The X-ray signature of the solar axion flux observed by XMM-Newton

    CERN Document Server

    Fraser, G W; Sembay, S; Carter, J A; Schyns, E

    2014-01-01

    Recent calculations of the 3-D scattering of X-rays produced by the conversion of solar axions suggest that the sunward magnetosphere could be a source of 0.2-10keV photons, observable without violating the Sun-/Earth-avoidance constraints of operational telescopes. Observed from High Earth Orbit, this conversion X-ray intensity may be seasonally modulated due to the changing visibility of the sunward magnetic field region. A simple model of the geomagnetic field is combined with the full ephemeris of XMM to predict the seasonal variation of the conversion X-ray intensity and its north-south asymmetry relative to the ecliptic. This model is compared with stacked XMM EPIC pn, MOS1 and MOS2 blank sky datasets from which point sources have been systematically removed and which have been rigorously screened against 1-500keV soft protons. Remarkably, when the residual flux is segregated according to spacecraft season, a very significant (>3sigma), seasonally-varying X-ray background signal is observed. The EPIC co...

  15. Potential solar axion signatures in X-ray observations with the XMM-Newton observatory

    OpenAIRE

    Fraser, G. W.; Read, A. M.; Sembay, S.; Carter, J. A.; Schyns, E.

    2014-01-01

    The soft X-ray flux produced by solar axions in the Earth's magnetic field is evaluated in the context of ESA's XMM-Newton observatory. Recent calculations of the scattering of axion-conversion X-rays suggest that the sunward magnetosphere could be an observable source of 0.2-10 keV photons. For XMM-Newton, any conversion X-ray intensity will be seasonally modulated by virtue of the changing visibility of the sunward magnetic field region. A simple model of the geomagnetic field is combined w...

  16. Solar axions as an energy source and modulator of the Earth magnetic field

    OpenAIRE

    Rusov, V. D.; Linnik, E. P.; Kudela, K.; Mavrodiev, S. Cht.; Zelentsova, T. N.; Smolyar, V. P.; Merkotan, K. K.

    2010-01-01

    We show existence of strong negative correlation between the temporal variations of magnetic field toroidal component of the solar tachocline (the bottom of convective zone) and the Earth magnetic field (Y-component). The possibility that hypothetical solar axions, which can transform into photons in external electric or magnetic fields (the inverse Primakoff effect), can be the instrument by which the magnetic field of convective zone of the Sun modulates the magnetic field of the Earth is c...

  17. Axion mechanism of the Sun luminosity and solar dynamo - geodynamo connection

    OpenAIRE

    Rusov, V. D.; Linnik, E. P.; Kudela, K.; Mavrodiev, S. Cht.; Sharph, I. V.; Zelentsova, T. N.; Beglaryan, R.; Smolyar, V. P.; Merkotan, K. K.

    2010-01-01

    We show existence of strong negative correlation between the temporal variations of magnetic field toroidal component of the solar tachocline (the bottom of convective zone) and the Earth magnetic field (Y-component). The possibility that hypothetical solar axions, which can transform into photons in external electric or magnetic fields (the inverse Primakoff effect), can be the instrument by which the magnetic field of convective zone of the Sun modulates the magnetic field of the Earth is c...

  18. Axions-motivation, limits and searches

    International Nuclear Information System (INIS)

    The axion solution of the strong CP problem provides a number of possible windows to physics beyond the standard model, notably in the form of searches for solar axions and for galactic axion dark matter, but in a broader context also inspires searches for axion-like particles in pure laboratory experiments. We briefly review the motivation for axions, astrophysical limits, their possible cosmological role, and current searches for axions and axion-like particles

  19. Solar axions as an energy source and modulator of the Earth magnetic field

    CERN Document Server

    Rusov, V D; Kudela, K; Mavrodiev, S Cht; Zelentsova, T N; Smolyar, V P; Merkotan, K K

    2010-01-01

    We show existence of strong negative correlation between the temporal variations of magnetic field toroidal component of the solar tachocline (the bottom of convective zone) and the Earth magnetic field (Y-component). The possibility that hypothetical solar axions, which can transform into photons in external electric or magnetic fields (the inverse Primakoff effect), can be the instrument by which the magnetic field of convective zone of the Sun modulates the magnetic field of the Earth is considered. We propose the axion mechanism of "solar dynamo-geodynamo" connection, where an energy of axions, which form in the Sun core, is modulated at first by the magnetic field of the solar tachocline zone (due to the inverse coherent Primakoff effect) and after that is absorbed in the liquid core of the Earth under influence of the terrestrial magnetic field, thereby playing the role of an energy source and a modulator of the Earth magnetic field. Within the framework of this mechanism new estimations of the strength...

  20. Proposed National Large Solar Telescope

    Indian Academy of Sciences (India)

    Jagdev Singh

    2008-03-01

    Sun’s atmosphere is an ideal place to study and test many magnetohydrodynamic (MHD) processes controlling turbulent plasma. We wish to resolve some of the finest solar features (which remain unresolved presently) and study their dynamics. Indian Institute of Astrophysics has proposed to design, fabricate and install a 2-meter class solar telescope at a suitable site in India to resolve features on the Sun of the size of about 0.1 arcsec. The focal plane instruments will include a high resolution polarimeteric package to measure polarization with an accuracy of 0.01 per cent; a high spectral resolution spectrograph to obtain spectra in 5 widely separated absorption lines simultaneously and high spatial resolution narrow band imagers in various lines. The Himalayan region appears to be a good choice keeping in view the prevailing dry and clear weather conditions. We have started detailed analysis of the weather conditions in the area and at some other locations in India. The site characterization will be done using the Sun-photometer, S-DIMM and SHABAR techniques to determine the seeing conditions.

  1. Detection chamber for search of low Mass WIMP and solar axions

    CERN Document Server

    Ovchinnikov, B M

    2016-01-01

    A chamber for direct detection of WIMPs with masses < 10 GeV/c2 and solar axions is developed. The chamber is filled with a gas mixture of H2 +3ppm TMAE (1,5,10 bar), or D2 + 3ppm TMAE. These gas fillings make it possible to suppress an electron background. For detection of events, the system GEM+pin-anode with a multiplication coefficient of about 10E+05 is constructed.

  2. Results on axion physics from the CAST Experiment at CERN

    CERN Document Server

    Eleftheriadis, Christos A; Aune, S; Barth, K; Belov, A; Beltran, B; Bräuninger, H; Carmona, J; Cebrián, S; Collar, J I; Dafni, T; Davenport, M; Di Lella, L; Englhauser, J; Fanourakis, G K; Ferrer-Ribas, E; Fischer, H; Franz, J; Friedrich, P; Geralis, T; Giomataris, Ioanis; Gninenko, S; Gomez, H; Hasinoff, M; Heinsius, F H; Hoffmann, D H H; Irastorza, I G; Jacoby, J; Jakovcic, K; Kang, D; Königsmann, K C; Kotthaus, R; Krcmar, M; Kousouris, K; Kuster, M; Laki, B; Lasseur, C; Liolios, A; Ljubicic, cA; Lutz, G; Luzón, G; Miller, D; Morales, A; Morales, J; Nordt, A; Ortiz, A; Papaevangelou, T; Placci, A; Raffelt, G; Riege1, H; Rodríguez, A; Ruz, J; Savvidis, I; Semertzidis, Y K; Serpico, Pasquale Dario; Stewart, L; Villar, J; Vogel, J; Walckiers, L; Zioutas, K

    2007-01-01

    Axions are expected to be produced in the sun via the Primakoff process. They may be detected through the inverse process in the laboratory, under the influence of a strong magnetic field, giving rise to X-rays of energies in the range of a few keV. Such an Axion detector is the CERN Axion Solar Telescope (CAST), collecting data since 2003. Results have been published, pushing the axion-photon coupling g$_{a\\gamma}$ below the 10$^{-10}$ GeV$^{-1}$ limit at 95% CL, for axion masses less than 0.02 eV. This limit is nearly an order of magnitude lower than previous experimental limits and surpassed for the first time limits set from astrophysical arguments based on the energy-loss concept. The experiment is currently exploring axion masses in the range of 0.02 eV $< m_a <$ 1.1 eV. In the next run, currently under preparation, the axion mass explored will be extended up to the limit of 1.1 eV, testing for the first time the region of theoretical axion models with the axion helioscope method.

  3. Pierre Sikivie from the University of Florida invented the working principle of all magnetic axion telescopes, such as CAST.

    CERN Multimedia

    Claudia Marcelloni

    2006-01-01

    The possible existence of axions in the universe means that they are a candidate for (very) cold dark matter, as another axion pioneer, Pierre Sikivie, from the University of Florida explained during the first Joint ILIAS-CAST-CERN Axion Training workshop. He also described the technique that he invented in 1983 for detecting axions. The idea is that axions in the galactic halo may be resonantly converted to microwave photons in a cavity permeated by a strong magnetic field.

  4. Search for hadronic axions

    International Nuclear Information System (INIS)

    The existence of axions, proposed as very light neutral pseudoscalar bosons, would solve the strong CP problem in the QCD. Axions also arise in supersymmetric and superstring theories and are candidates for dark matter in the universe. Cosmological and astrophysical arguments restrict the masses (ma) of invisible axions to rather narrow 10-5 eV → ma → 10-22 eV range, but with large uncertainties on either side. The KSVZ or hadronic axion is one version of invisible axions, which predicts small coupling of axions to electrons. Models of hadronic axions with E/N ≅ 2 allow for a near or complete cancellation of the axion-photon coupling constant. In this case there is no stellar-evolution limits on ma and for hadronic axions there exists a small window 10 eV ≤ ma ≤ 40 eV between supernova cooling and axion burst arguments. So far the best and only discussed candidate for hot dark matter has been the massive neutrino with a mass of a few eV. Because the Super-Kamiokande experiment suggests the tau neutrino mass of only 0.03-0.1 eV, the hadronic axion in the so-called hadronic axion window could be a good candidate for a cosmological hot dark matter within the mixed dark matter scenario. To verify this window one can search for axions by appealing only to their coupling to nucleons. The most promising methods are the observation of an axion burst from a future supernova and the resonant absorption of almost monochromatic solar axions. We have performed the first experiment along this new line of solar axion investigations. Using a small target of 0.03 g of 57Fe we have made a search for 14.4 keV gamma rays induced by resonant absorption of almost monochromatic solar axions. These Doppler broadened axions could be emitted from the Sun, in M1 transition between the first, thermally excited state and the ground state of 57Fe. An upper limit on hadronic axion mass of 745 eV is obtained at the 95 % confidence level. Search for solar axions is beginning to become

  5. Introduction to the Solar Space Telescope

    Indian Academy of Sciences (India)

    G. Ai; S. Jin; S. Wang; B. Ye; S. Yang

    2000-09-01

    The design of the space solar telescope (SST) (phase B) has been completed. The manufacturing is under development. At the end of 2000, it will be assembled. The basic aspect will be introduced in this paper.

  6. Bounds on galactic cold dark matter particle candidates and solar axions from a Ge-spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Gelmini, G.

    1986-11-01

    The ultralow background Ge spectrometer developed by the USC/PNL group is used as a detector of cold dark matter candidates from the halo of our galaxy and of solar axions (and other light bosons), yielding interesting bounds. Some of them are: heavy standard Dirac neutrinos with mass 20 GeV less than or equal to m less than or equal to 1 TeV are excluded as main components of the halo of our galaxy; Dine-Fischler-Srednicki axion models with F/2x/sub e/' less than or equal to 0.5 x 10/sup 7/ GeV are excluded. 22 refs., 7 figs.

  7. Search for spectral irregularities due to photon-axion-like particle oscillations with the Fermi Large Area Telescope

    CERN Document Server

    ,

    2016-01-01

    We report on the search for spectral irregularities induced by oscillations between photons and axion-like particles (ALPs) in the $\\gamma$-ray spectrum of NGC 1275, the central galaxy of the Perseus cluster. Using six years of Fermi Large Area Telescope data, we find no evidence for ALPs and exclude couplings above $5\\times10^{-12}\\,\\mathrm{GeV}^{-1}$ for ALP masses $0.5 \\lesssim m_a \\lesssim 5$ neV at 95% confidence. The limits are competitive with the sensitivity of planned laboratory experiments, and, together with other bounds, strongly constrain the possibility that ALPs can reduce the $\\gamma$-ray opacity of the Universe.

  8. Search for Solar Axions Produced in $p(d,\\rm{^3He})A$ Reaction with Borexino Detector

    CERN Document Server

    ,

    2012-01-01

    A search for 5.5-MeV solar axions produced in the $p+d\\rightarrow\\rm{^3He}+A (5.5 \\rm{MeV})$ reaction was performed using the Borexino detector. The Compton conversion of axions to photons, ${\\rm A}+e\\rightarrow e+\\gamma$; the axio-electric effect, ${\\rm A}+e+Z\\rightarrow e+Z$; the decay of axions into two photons, ${\\rm A}\\rightarrow2\\gamma$; and inverse Primakoff conversion on nuclei, ${\\rm A}+Z\\rightarrow\\gamma+Z$, are considered. Model independent limits on axion-electron ($g_{Ae}$), axion-photon ($g_{A\\gamma}$), and isovector axion-nucleon ($g_{3AN}$) couplings are obtained: $|g_{Ae}\\times g_{3AN}| \\leq 5.5\\times 10^{-13}$ and $|g_{A\\gamma}\\times g_{3AN}| \\leq 4.6\\times 10^{-11} \\rm{GeV}^{-1}$ at $m_A <$ 1 MeV (90% c.l.). These limits are 2-4 orders of magnitude stronger than those obtained in previous laboratory-based experiments using nuclear reactors and accelerators.

  9. Axion-photon couplings in invisible axion models

    International Nuclear Information System (INIS)

    We reexamine the axion-photon couplings in various invisible axion models motivated by the recent proposal of using optical interferometry at the ASST facility at the SSCL to search for the axion. We illustrate that the assignment of U(1)PQ charges for the fermion fields plays an important role in determining the couplings. Several simple nonminimal invisible axion models with suppressed and enhanced axion-photon couplings are constructed, respectively. We also discuss the implications of possible new experiments to detect solar axions by conversion to x rays in a static magnetic apparatus tracking the Sun

  10. Axion BEC: A model beyond CDM

    Science.gov (United States)

    Yang, Qiaoli

    the right properties to be cold dark matter. It was also realized that the existence of axions or axion like particles (ALPs) can be probed experimentally by exploiting their coupling to photons[30]. The ADMX experiment is a realization of the concept of the axion haloscope, in which halo axions in an electromagnetic cavity permeated by magnetic field are induced to convert to microwave photons, which may then be picked up by an antenna. The CERN Axion Solar Telescope (CAST) and the Tokyo Helioscope are axion helioscopes which convert axions from the Sun into X-rays in a magnetic field. A third type of experiment is called photon regeneration[99]. In these experiments photons in a laser beam are converted to axions in a magnetic field. The axions travel unimpeded through a wall, behind which is an identical setup of magnets, where some axions are converted back to photons which can be detected. The three major candidates for CDM, axions/ALPs, WIMPs, and sterile neutrinos, were thought until recently to be indistinguishable by purely astronomical and cosmological observations. However, axions/ALPs are very different from the other two in terms of statistical mechanics properties. Axions/ALPs are spin 0 particles and form a highly degenerate Bose fluid while the typical WIMPs such as neutralinos and sterile neutrinos are fermions and are not degenerate. It was recently found [5] that cold axions are not only a highly degenerate bose fluid, but also form a Bose-Einstein condensate (BEC). Therefore, if the CDM particles are indeed axions/ALPs, there is an opportunity to distinguish them from the other candidates on observational grounds. In this thesis, Chapter 1 is an introduction to cosmology and the evidence for CDM. Chapter 2 introduces axion/ALPs physics. Chapter 3 provides an introduction to the axion/ALPs detection experiments and the constraints on axion/ALP parameter space. Chapter 4 shows quantitatively that cold axions do form a BEC. Chapter 5 discusses the

  11. NLST: India's National Large Solar Telescope

    Science.gov (United States)

    Hasan, S. S.; Soltau, D.; Kärcher, H.; Süß, M.; Berkefeld, T.

    2010-06-01

    This article introduces the new Indian 2 m telescope which has been designed by MT Mechatronics in a detailed conceptual design study for the Indian Institute of Astrophysics, Bangalore. We describe the background of the project and the science goals which shall be addressed with this telescope. NLST is a solar telescope with high optical throughput and will be equipped with an integrated Adaptive Optics system. It is optimized for a site with the kind of seeing and wind conditions as they are expected at a lake site in the Himalayan mountains. The telescope can also be used for certain night time applications. We also give the scientific rationale for this class of telescope.

  12. Review of the solar array telescopes

    OpenAIRE

    Smith, D. A.

    2005-01-01

    For several years the only experiments sensitive to astrophysical gamma rays with energies beyond the reach of EGRET but below that the Cherenkov imaging telescopes have been the "solar towar" detectors. They use > 2000 m$^{2}$ mirror areas to sample the Cherenkov wavefront generated by

  13. The GREGOR Solar Telescope on Tenerife

    Czech Academy of Sciences Publication Activity Database

    Schmidt, W.; von der Lühe, O.; Volkmer, R.; Denker, C.; Solanki, S.K.; Balthasar, H.; Bello González, N.; Berkefeld, T.; Collados Vera, M.; Hofmann, A.; Kneer, F.; Lagg, A.; Puschmann, K.G.; Schmidt, D.; Sobotka, Michal; Soltau, D.; Strassmeier, K.G.

    San Francisco : Astronomical Society otf the Pacific, 2012 - (Rimmele, T.), s. 365-376 ISBN 9781583818084. - (ASP Conference Series. 463). [ATST - EAST Workshop in Solar Physics /2./. Washington (US), 09.11.2011-11.11.2011] Institutional support: RVO:67985815 Keywords : telescope GREGOR * configuration Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  14. Cosmic axions

    International Nuclear Information System (INIS)

    Axion physics is briefly reviewed, including the constraints on the axion decay constant from laboratory experiments, from stellar evolution and from the cosmological axion energy density. Experiments to detect axions emitted by the sun or axions floating about in the halo of our galaxy are discussed. 19 references

  15. Solar Magnetism and the Activity Telescope at HSOS

    Institute of Scientific and Technical Information of China (English)

    Hong-Qi Zhang; Ya-Nan Wang; Qi-Qian Hu; Jun-Sun Xue; Hai-Tian Lu; Hou-Kun Ni; Han-Liang Chen; Xiao-Jun Zhou; Qing-Sheng Zhu; Lü-Jun Yuan; Yong Zhu; Dong-Guang Wang; Yuan-Yong Deng; Ke-Liang Hu; Jiang-Tao Su; Jia-Ben Lin; Gang-Hua Lin; Shi-Mo Yang; Wei-Jun Mao

    2007-01-01

    A new solar telescope system is described, which has been operating at Huairou Solar Observing Station (HSOS), National Astronomical Observatories, Chinese Academy of Sciences (CAS), since the end of 2005. This instrument, the Solar Magnetism and Activity Telescope (SMAT), comprises two telescopes which respectively make measurements of full solar disk vector magnetic field and Hα observation. The core of the full solar disk video vector magnetograph is a birefringent filter with 0.1(A) bandpass, installed in the tele-centric optical system of the telescope. We present some preliminary observational results of the full solar disk vector magnetograms and Hα filtergrams obtained with this telescope system.

  16. The Superconducting Toroid for the New International AXion Observatory (IAXO)

    CERN Document Server

    Shilon, I; Silva, H; Wagner, U; Kate, H H J ten

    2013-01-01

    IAXO, the new International AXion Observatory, will feature the most ambitious detector for solar axions to date. Axions are hypothetical particles which were postulated to solve one of the puzzles arising in the standard model of particle physics, namely the strong CP (Charge conjugation and Parity) problem. This detector aims at achieving a sensitivity to the coupling between axions and photons of one order of magnitude beyond the limits of the current detector, the CERN Axion Solar Telescope (CAST). The IAXO detector relies on a high-magnetic field distributed over a very large volume to convert solar axions to detectable X-ray photons. Inspired by the ATLAS barrel and end-cap toroids, a large superconducting toroid is being designed. The toroid comprises eight, one meter wide and twenty one meters long racetrack coils. The assembled toroid is sized 5.2 m in diameter and 25 m in length and its mass is about 250 tons. The useful field in the bores is 2.5 T while the peak magnetic field in the windings is 5....

  17. Anisotropy test of the axion-like particle Universe opacity effect: a case for the Cherenkov Telescope Array

    International Nuclear Information System (INIS)

    The opacity of the Universe to gamma rays is still poorly measured, in particular anomalies may have been observed. Assuming that such anomalies find their origin in conventional physics like intrinsic source spectra or the density of the extragalactic background light, they would be evenly distributed over the sky. If they exist, axion-like particles (ALPs) would have a potential effect on the opacity of the Universe to gamma rays, possibly related to the anomalies in the spectral indices of distant gamma-ray sources. Under the assumption that distant sources offer suitable environments for their production, ALPs convert back to photons in the Galactic magnetic field and their effect on the opacity is expected to depend on the position of the sources. In that case the anomaly is expected to exhibit peculiar correlations on the sky. We propose a method to test the origin of the opacity anomaly, based on angular correlations of spectral softening anomalies. Such a diagnosis requires a wide-field survey of high-energy gamma-ray sources over a broad range of energy. The future Cherenkov Telescope Array (CTA) is perfectly suited to perform such a study. It is shown that while the current sample of sources is not large enough to base conclusions on, with this method CTA will be sensitive to ALP couplings to gamma rays of the order of 3 × 10−11GeV−1 for ALP masses below 10−8 eV

  18. Sensitivity of the Cherenkov Telescope Array to the detection of axion-like particles at high gamma-ray opacities

    International Nuclear Information System (INIS)

    Extensions of the Standard Model of particles commonly predict the existence of axion(-like) particles (ALPs) that could be detected through their coupling to photons in external magnetic fields. This coupling could lead to modifications of γ-ray spectra from extragalactic sources. Above a certain energy, the γ-ray flux should be exponentially damped due to the interaction with photons of background radiations fields. ALPs, on the other hand, propagate unimpeded over cosmological distances and a reconversion into γ-rays could lead to an additional component in the spectra. Here, we present the sensitivity of the proposed Cherenkov Telescope Array (CTA) to detect this spectral hardening. Using the full instrumental response functions of CTA, a combined likelihood analysis of four γ-ray sources shows that a significant detection of the ALP signal is possible for couplings gaγ ≳ 2 × 10−11 GeV−1 and ALP masses ma ∼< 100 neV. We discuss the dependency of these values on different model assumptions and magnetic-field scenarios and identify the best observation strategy to search for an ALP induced boost of the γ-ray flux

  19. Solar Rejection Filter for Large Telescopes

    Science.gov (United States)

    Hemmati, Hamid; Lesh, James

    2009-01-01

    To reject solar radiation photons at the front aperture for large telescopes, a mosaic of large transmission mode filters is placed in front of the telescope or at the aperture of the dome. Filtering options for effective rejection of sunlight include a smaller filter down-path near the focus of the telescope, and a large-diameter filter located in the front of the main aperture. Two types of large filters are viable: reflectance mode and transmittance mode. In the case of reflectance mode, a dielectric coating on a suitable substrate (e.g. a low-thermal-expansion glass) is arranged to reflect only a single, narrow wavelength and to efficiently transmit all other wavelengths. These coatings are commonly referred to as notch filter. In this case, the large mirror located in front of the telescope aperture reflects the received (signal and background) light into the telescope. In the case of transmittance mode, a dielectric coating on a suitable substrate (glass, sapphire, clear plastic, membrane, and the like) is arranged to transmit only a single wavelength and to reject all other wavelengths (visible and near IR) of light. The substrate of the large filter will determine its mass. At first glance, a large optical filter with a diameter of up to 10 m, located in front of the main aperture, would require a significant thickness to avoid sagging. However, a segmented filter supported by a structurally rugged grid can support smaller filters. The obscuration introduced by the grid is minimal because the total area can be made insignificant. This configuration can be detrimental to a diffraction- limited telescope due to diffraction effects at the edges of each sub-panel. However, no discernable degradation would result for a 20 diffraction-limit telescope (a photon bucket). Even the small amount of sagging in each subpanel should have minimal effect in the performance of a non-diffraction limited telescope because the part has no appreciable optical power. If the

  20. Axion helioscopes update: the status of CAST and IAXO

    CERN Document Server

    Dafni, T

    2014-01-01

    Almost 35 years since their suggestion as a good solution to the strong CP-problem, axions remain one of the few viable candidates for the Dark Matter, although still eluding detection. Most of the methods for their detection are based on their coupling to photons, one of the most sensitive ones being the helioscope technique. We report on the current status of the CERN Axion Solar Telescope and the future International Axion Observatory (IAXO). Recent results from the second part of CAST phase II, where the magnet bores were filled with 3He gas at variable pressure achieving sensibilities on the axion mass up to 1.2 eV, are presented. Currently, CAST is expecting to improve its sensitivity to solar axions with rest mass below 0.02 eV/c^2 after the upgrade of the X-ray detectors and with the implementation of a second X-ray optic. At the same time, it is exploring other possibilities at the low energy physics frontier. On the other hand IAXO, the fourth generation axion helioscope, aims to improve CAST's perf...

  1. Tokyo Axion Helioscope

    CERN Document Server

    Minowa, M; Akimoto, Y; Ohta, R; Mizumoto, T; Yamamoto, A

    2008-01-01

    A new search result of the Tokyo axion helioscope is presented. The axion helioscope consists of a dedicated cryogen-free 4T superconducting magnet with an effective length of 2.3 m and PIN photodiodes as x-ray detectors. Solar axions, if exist, would be converted into X-ray photons through the inverse Primakoff process in the magnetic field. Conversion is coherently enhanced even for massive axions by filling the conversion region with helium gas. The present third phase measurement sets a new limit of g_{a\\gamma\\gamma}<(5.6--13.4)\\times10^{-10} GeV^{-1} for the axion mass of 0.84

  2. GREGOR: the New German Solar Telescope

    Czech Academy of Sciences Publication Activity Database

    Balthasar, H.; von der Lühe, O.; Kneer, F.; Staude, J.; Volkmer, R.; Berkefeld, T.; Caligari, P.; Collados, M.; Halbgewachs, C.; Heidecke, F.; Hofmann, A.; Klvaňa, Miroslav; Nicklas, H.; Popow, E.; Puschmann, K.G.; Schmidt, W.; Sobotka, Michal; Soltau, D.; Strassmeier, K.G.; Wittmann, A.

    San Francisco: Astronomical Society of the Pacific, 2007 - (Heinzel, P.; Dorotovič, I.; Rutten, R.), s. 605-610. (ASP Conference Series. 368). ISBN 978-1-583812-36-5. [Solar Physics Meeting. Coimbra (PT), 09.10.2006-13.10.2006] Grant ostatní: EU(XE) HPRN-CT-2002-00313 Institutional research plan: CEZ:AV0Z10030501 Source of funding: V - iné verejné zdroje Keywords : telescope * description Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  3. Determination of effective axion masses in the helium-3 buffer of CAST

    Energy Technology Data Exchange (ETDEWEB)

    Ruz, J

    2011-11-18

    The CERN Axion Solar Telescope (CAST) is a ground based experiment located in Geneva (Switzerland) searching for axions coming from the Sun. Axions, hypothetical particles that not only could solve the strong CP problem but also be one of the favored candidates for dark matter, can be produced in the core of the Sun via the Primakoff effect. They can be reconverted into X-ray photons on Earth in the presence of strong electromagnetic fields. In order to look for axions, CAST points a decommissioned LHC prototype dipole magnet with different X-ray detectors installed in both ends of the magnet towards the Sun. The analysis of the data acquired during the first phase of the experiment yielded the most restrictive experimental upper limit on the axion-to-photon coupling constant for axion masses up to about 0.02 eV/c{sup 2}. During the second phase, CAST extends its mass sensitivity by tuning the electron density present in the magnetic field region. Injecting precise amounts of helium gas has enabled CAST to look for axion masses up to 1.2 eV/c{sup 2}. This paper studies the determination of the effective axion masses scanned at CAST during its second phase. The use of a helium gas buffer at temperatures of 1.8 K has required a detailed knowledge of the gas density distribution. Complete sets of computational fluid dynamic simulations validated with experimental data have been crucial to obtain accurate results.

  4. Determination of effective axion masses in the helium-3 buffer of CAST

    International Nuclear Information System (INIS)

    The CERN Axion Solar Telescope (CAST) is a ground based experiment located in Geneva (Switzerland) searching for axions coming from the Sun. Axions, hypothetical particles that not only could solve the strong CP problem but also be one of the favored candidates for dark matter, can be produced in the core of the Sun via the Primakoff effect. They can be reconverted into X-ray photons on Earth in the presence of strong electromagnetic fields. In order to look for axions, CAST points a decommissioned LHC prototype dipole magnet with different X-ray detectors installed in both ends of the magnet towards the Sun. The analysis of the data acquired during the first phase of the experiment yielded the most restrictive experimental upper limit on the axion-to-photon coupling constant for axion masses up to about 0.02 eV/c2. During the second phase, CAST extends its mass sensitivity by tuning the electron density present in the magnetic field region. Injecting precise amounts of helium gas has enabled CAST to look for axion masses up to 1.2 eV/c2. This paper studies the determination of the effective axion masses scanned at CAST during its second phase. The use of a helium gas buffer at temperatures of 1.8 K has required a detailed knowledge of the gas density distribution. Complete sets of computational fluid dynamic simulations validated with experimental data have been crucial to obtain accurate results.

  5. An improved limit on the axion-photon coupling from the CAST experiment

    International Nuclear Information System (INIS)

    We have searched for solar axions or similar particles that couple to two photons by using the CERN Axion Solar Telescope (CAST) set-up with improved conditions in all detectors. From the absence of excess x-rays when the magnet was pointing to the Sun, we set an upper limit on the axion-photon coupling of gaγ ≤ 8.8 x 10-11 GeV-1 at 95% CL for ma ≤ 0.02 eV. This result is the best experimental limit over a broad range of axion masses and for ma ≤ 0.02 eV also supersedes the previous limit derived from energy-loss arguments on globular cluster stars. (authors)

  6. The X-ray Telescope of CAST

    OpenAIRE

    M. Kuster(Technische Universität Darmstadt); Bräuninger, H.; Cébrian, S.; Davenport, M.; Elefteriadis, C.; Englhauser, J.; Fischer, H.; Franz, J.; Friedrich, P.; Hartmann, R.; Heinsius, F. H.; Hoffmann, D H H; Hoffmeister, G.; Joux, J. N.; Kang, D.

    2007-01-01

    The Cern Axion Solar Telescope (CAST) is in operation and taking data since 2003. The main objective of the CAST experiment is to search for a hypothetical pseudoscalar boson, the axion, which might be produced in the core of the sun. The basic physics process CAST is based on is the time inverted Primakoff effect, by which an axion can be converted into a detectable photon in an external electromagnetic field. The resulting X-ray photons are expected to be thermally distributed between 1 and...

  7. Transplanckian axions !?

    CERN Document Server

    Montero, Miguel; Valenzuela, Irene

    2015-01-01

    We discuss quantum gravitational effects in Einstein theory coupled to periodic axion scalars to analyze the viability of several proposals to achieve superplanckian axion periods (aka decay constants) and their possible application to large field inflation models. The effects we study correspond to the nucleation of euclidean gravitational instantons charged under the axion, and our results are essentially compatible with (but independent of) the Weak Gravity Conjecture, as follows: Single axion theories with superplanckian periods contain gravitational instantons inducing sizable higher harmonics in the axion potential, which spoil superplanckian inflaton field range. A similar result holds for multi-axion models with lattice alignment (like the Kim-Nilles-Peloso model). Finally, theories with $N$ axions can still achieve a moderately superplanckian periodicity (by a $\\sqrt{N}$ factor) with no higher harmonics in the axion potential. The Weak Gravity Conjecture fails to hold in this case due to the absence ...

  8. Probing eV-scale axions with CAST

    CERN Document Server

    Arik, E; Autiero, D; Barth, K; Belov, A; Beltrán, B; Borghi, S; Bourlis, G; Boydag, F S; Bräuninger, H; Carmona, J M; Cebrián, S; Cetin, S A; Collar, J I; Dafni, T; Davenport, M; Di Lella, L; Dogan, O B; Eleftheriadis, C; Elias, N; Fanourakis, G K; Ferrer-Ribas, E; Fischer, H; Friedrich, P; Franz, J; Galán, J; Geralis, T; Giomataris, Yu; Gninenko, S; Gómez, H; Hartmann, R; Hasinoff, M; Heinsius, F H; Hikmet, I; Hoffmann, D H H; Irastorza, I G; Jacoby, J; Jakovcic, K; Kang, D; Königsmann, K C; Kotthaus, R; Krcmar, M; Kousouris, K; Kuster, M; Lakic, B; Lasseur, C; Liolios, A; Ljubicic, A; Lutz, G; Luzón, G; Miller, D; Morales, J; Niinikoski, T; Nordt, A; Ortiz, A; Papaevangelou, T; Pivovaroff, M J; Placci, A; Raffelt, G; Riege, H; Rodríguez, A; Ruz, J; Sawidis, I; Semertzidis, Y; Serpico, P; Soufli, R; Stewart, L; van Bibber, K; Villar, J; Vogel, J; Walckiers, L; Zioutas, K

    2009-01-01

    We have searched for solar axions or other pseudoscalar particles that couple to two photons by using the CERN Axion Solar Telescope (CAST) setup. Whereas we previously have reported results from CAST with evacuated magnet bores (Phase I), setting limits on lower mass axions, here we report results from CAST where the magnet bores were filled with \\hefour gas (Phase II) of variable pressure. The introduction of gas generated a refractive photon mass $m_\\gamma$, thereby achieving the maximum possible conversion rate for those axion masses \\ma that match $m_\\gamma$. With 160 different pressure settings we have scanned \\ma up to about 0.4 eV, taking approximately 2 h of data for each setting. From the absence of excess X-rays when the magnet was pointing to the Sun, we set a typical upper limit on the axion-photon coupling of $\\gag\\lesssim 2.17\\times 10^{-10} {\\rm GeV}^{-1}$ at 95% CL for $\\ma \\lesssim 0.4$ eV, the exact result depending on the pressure setting. The excluded parameter range covers realistic axio...

  9. Axion cosmology

    Science.gov (United States)

    Marsh, David J. E.

    2016-07-01

    Axions comprise a broad class of particles that can play a major role in explaining the unknown aspects of cosmology. They are also well-motivated within high energy physics, appearing in theories related to CP-violation in the standard model, supersymmetric theories, and theories with extra-dimensions, including string theory, and so axion cosmology offers us a unique view onto these theories. I review the motivation and models for axions in particle physics and string theory. I then present a comprehensive and pedagogical view on the cosmology and astrophysics of axion-like particles, starting from inflation and progressing via BBN, the CMB, reionization and structure formation, up to the present-day Universe. Topics covered include: axion dark matter (DM); direct and indirect detection of axions, reviewing existing and future experiments; axions as dark radiation; axions and the cosmological constant problem; decays of heavy axions; axions and stellar astrophysics; black hole superradiance; axions and astrophysical magnetic fields; axion inflation, and axion DM as an indirect probe of inflation. A major focus is on the population of ultralight axions created via vacuum realignment, and its role as a DM candidate with distinctive phenomenology. Cosmological observations place robust constraints on the axion mass and relic density in this scenario, and I review where such constraints come from. I next cover aspects of galaxy formation with axion DM, and ways this can be used to further search for evidence of axions. An absolute lower bound on DM particle mass is established. It is ma > 10-24eV from linear observables, extending to ma ≳ 10-22eV from non-linear observables, and has the potential to reach ma ≳ 10-18eV in the future. These bounds are weaker if the axion is not all of the DM, giving rise to limits on the relic density at low mass. This leads to the exciting possibility that the effects of axion DM on structure formation could one day be detected

  10. New vacuum solar telescope and observations with high resolution

    International Nuclear Information System (INIS)

    The New Vacuum Solar Telescope (NVST) is a one meter vacuum solar telescope that aims to observe fine structures on the Sun. The main goals of NVST are high resolution imaging and spectral observations, including measurements of the solar magnetic field. NVST is the primary ground-based facility used by the Chinese solar research community in this solar cycle. It is located by Fuxian Lake in southwest China, where the seeing is good enough to perform high resolution observations. We first introduce the general conditions at the Fuxian Solar Observatory and the primary science cases of NVST. Then, the basic structures of this telescope and instruments are described in detail. Finally, some typical high resolution data of the solar photosphere and chromosphere are also shown

  11. Algorithm Design and Test of the Solar Guide Telescope

    Institute of Scientific and Technical Information of China (English)

    Wei-Bin Wen; Sheng-Zhen Jin

    2004-01-01

    The Solar Guide Telescope (SGT), an important solar attitude sensor of the SST (Space Solar Telescope, a space solar observing instrument being developed in China), can accurately produce pointing error signals of the SST for attitude control at high speed. We analyze in detail the error algorithm of the heliocentric coordinates and the edge judging of solar images. The measuring accuracy of ±0.5arcsec of the SGT is verified by experiments on the tracking of the Sun and by testing a sun simulator. Some factors causing the pointing errors are examined.

  12. New Superconducting Toroidal Magnet System for IAXO, the International AXion Observatory

    CERN Document Server

    Shilon, I; Silva, H; Wagner, U; Kate, H H J ten

    2013-01-01

    Axions are hypothetical particles that were postulated to solve one of the puzzles arising in the standard model of particle physics, namely the strong CP (Charge conjugation and Parity) problem. The new International AXion Observatory (IAXO) will incorporate the most promising solar axions detector to date, which is designed to enhance the sensitivity to the axion-photon coupling by one order of magnitude beyond the limits of the current state-of-the-art detector, the CERN Axion Solar Telescope (CAST). The IAXO detector relies on a high-magnetic field distributed over a very large volume to convert solar axions into X-ray photons. Inspired by the successful realization of the ATLAS barrel and end-cap toroids, a very large superconducting toroid is currently designed at CERN to provide the required magnetic field. This toroid will comprise eight, one meter wide and twenty one meter long, racetrack coils. The system is sized 5.2 m in diameter and 25 m in length. Its peak magnetic field is 5.4 T with a stored e...

  13. Auxiliary full-disc telescope for the European Solar Telescope

    Czech Academy of Sciences Publication Activity Database

    Sobotka, Michal; Klvaňa, Miroslav; Melich, Zbyněk; Rail, Zdeněk; Bettonvil, F.; Gelly, B.

    Bellingham : SPIE, 2010 - (McLean, I.), 77351Z-1-77351Z-8 ISBN 9780819482259. - (Proceedings of SPIE. 7735). [Ground-based and Airborne Instrumentation for Astronomy III. San Diego (US), 27.06.2010-02.07.2010] Grant ostatní: EU(XE) 212482 Institutional research plan: CEZ:AV0Z10030501; CEZ:AV0Z20430508 Keywords : auxiliary full-disc telescope * principal functions Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  14. Bringing Perfect Vision to the Daniel K. Inouye Solar Telescope

    Science.gov (United States)

    Matijevich, Russ; Johansson, Erik; Johnson, Luke; Cavaco, Jeff; National Solar Observatory

    2016-01-01

    The world's largest ground-based solar telescope is one step closer to operation with the acceptance of the deformable mirror engineered by AOA Xinetics, a Northrop Grumman Corporation company. The Daniel K. Inouye Solar Telescope (DKIST), currently under construction in Haleakala, Hawaii, will offer unprecedented high-resolution images of the sun using the latest adaptive optics technology to provide its distortion-free imaging.Led by the National Solar Observatory (NSO) and the Association of Universities for Research in Astronomy (AURA), the Inouye Solar Telescope will help scientists better understand how magnetic fields affect the physical properties of the Sun, what roles they play in our solar system and how they affect Earth.Ground-based telescopes, whether observing the sun or the night sky must contend with atmospheric turbulence that acts as a flexible lens, constantly reshaping observed images. This turbulence makes research on solar activity difficult and drives the need for the latest adaptive optics technology.To provide DKIST with the distortion-free imaging it requires, AOA Xinetics designed a deformable mirror with 1,600 actuators, four times the normal actuator density. This deformable mirror (DM) is instrumental in removing all of the atmospheric blurriness that would otherwise limit the telescope's performance. The mirror also has an internal thermal management system to handle the intense solar energy coming from DKIST's telescope. This poster provides the history behind this incredible success story.

  15. Solar Hα and white light telescope at Hvar Observatory

    Czech Academy of Sciences Publication Activity Database

    Čalogovic, J.; Dumbovic, M.; Novak, S.; Vršnak, B.; Brajša, R.; Pötzi, W.; Hirtenfellner-Polanec, W.; Veronig, A.; Hanslmeier, A.; Klvaňa, Miroslav; Ambrož, Pavel

    2012-01-01

    Roč. 36, č. 2012 (2012), s. 83-88. ISSN 1845-8319 Institutional support: RVO:67985815 Keywords : solar observations * telescope * photosphere Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  16. A retrospective of the GREGOR solar telescope in scientific literature

    CERN Document Server

    Denker, C; Feller, A; Arlt, K; Balthasar, H; Bauer, S -M; González, N Bello; Berkefeld, T; Caligari, P; Collados, M; Fischer, A; Granzer, T; Hahn, T; Halbgewachs, C; Heidecke, F; Hofmann, A; Kentischer, T; Klvaňa, M; Kneer, F; Lagg, A; Nicklas, H; Popow, E; Puschmann, K G; Rendtel, J; Schmidt, D; Schmidt, W; Sobotka, M; Solanki, S K; Soltau, D; Staude, J; Strassmeier, K G; Volkmer, R; Waldmann, T; Wiehr, E; Wittmann, A D; Woche, M

    2012-01-01

    In this review, we look back upon the literature, which had the GREGOR solar telescope project as its subject including science cases, telescope subsystems, and post-focus instruments. The articles date back to the year 2000, when the initial concepts for a new solar telescope on Tenerife were first presented at scientific meetings. This comprehensive bibliography contains literature until the year 2012, i.e., the final stages of commissioning and science verification. Taking stock of the various publications in peer-reviewed journals and conference proceedings also provides the "historical" context for the reference articles in this special issue of Astronomische Nachrichten/Astronomical Notes.

  17. The Solar Optical Telescope for the Hinode Mission: An Overview

    CERN Document Server

    Tsuneta, S

    2007-01-01

    The Solar Optical Telescope (SOT) aboard the Hinode satellite (formerly called Solar-B) consists of the Optical Telescope Assembly (OTA) and the Focal Plane Package (FPP). The OTA is a 50 cm diffraction-limited Gregorian telescope, and the FPP includes the narrow-band (NFI) and wide-band (BFI) filtergraphs, plus the Stokes spectro-polarimeter (SP). SOT provides unprecedented high resolution photometric and vector magnetic images of the photosphere and chromosphere with a very stable point spread function, and is equipped with an image stabilization system that reduces the error to less than 0.01 arcsec rms. Together with the other two instruments on Hinode (the X-Ray Telescope (XRT) and EUV Imaging Spectrometer (EIS)), SOT is poised to address many fundamental questions about solar magneto-hydrodynamics. Note that this is an overview, and the details of the instrument are presented in a series of companion papers.

  18. Axion Cosmology

    CERN Document Server

    Marsh, David J E

    2015-01-01

    Axions comprise a broad class of particles that can play a major role in explaining the unknown aspects of cosmology. They are also extraordinarily well-motivated within high energy physics, and so axion cosmology offers us a unique view onto these theories. I present a comprehensive and pedagogical view on the cosmology and astrophysics of axion-like particles, starting from inflation and progressing via the CMB and structure formation up to the present-day Universe. I briefly review the motivation and models for axions in particle physics and string theory. The primary focus is on the population of ultralight axions created via vacuum realignment, and its role as a dark matter (DM) candidate with distinctive phenomenology. Cosmological observations place robust constraints on the axion mass and relic density in this scenario, and I review where such constraints come from. I next cover aspects of galaxy formation with axion DM, and ways this can be used to further search for evidence of axions. An absolute l...

  19. Domestic Axion

    CERN Document Server

    Dvali, Gia

    2016-01-01

    We attempt to identify a phenomenologically viable solution to the strong $CP$ problem in which the axion is composed entirely out of Standard Model fermion species. The axion consists predominantly of the $\\eta'$ meson with a minuscule admixture of a pseudoscalar bilinear composite of neutrinos, $\\eta_{\

  20. A feasibility study for measuring geomagnetic conversion of solar axions to x-rays in low Earth orbits

    International Nuclear Information System (INIS)

    We present a detailed computation of the expected rate for geomagnetic conversion of solar axions to x-rays (GECOSAX) along the orbit of an x-ray satellite. We use realistic satellite orbits and propagation in time. A realistic model for the Earth's magnetic field, which properly accounts for its spatial non-uniformity, is used. We also account for the effect of the Earth's atmosphere on the propagation of x-rays in our calculation of axion–photon conversion probability. To estimate possible sensitivities to the axion–photon coupling gaγ, we use an actual measurement of the expected backgrounds by the SUZAKU satellite. Assuming an effective detector area of 103 cm2 and about 106 s of data, we show that a 2 σ limit of gaγ−11 GeV−1 from GECOSAX is achievable, for axion masses ma−4 eV. This significantly exceeds current laboratory sensitivities to gaγ

  1. Development of new solar radio telescope in NICT

    Science.gov (United States)

    Kubo, Yuki; Watari, Shinichi; Ishii, Mamoru; Ishibashi, Hiromitsu; Iwai, Kazumasa

    Solar radio burst is one of the most important events for not only space weather forecasting but also investigating high-energy phenomena in solar corona. The GHz solar radio waves are synchrotron radiation emitted by high energy electrons at lower corona. On the other hand, the MHz solar radio bursts, especially type II and III bursts, are radiated via mode conversion of Langmuir waves excited by high energy electrons. These high energy electrons are accelerated at reconnection regions in solar flare and shock waves in solar corona. Therefore, MHz and GHz solar radio waves are closely related each other through the accelerated high energy electrons. So, wide frequency range (MHz to GHz) radio wave observations with high time resolution are required to comprehensively understand high energy phenomena in solar corona. We have been operating solar radio spectrograph called HiRAS for over twenty years in Hiraiso Solar Observatory, National Institute of Information and Communications Technology (NICT), but the system has been decrepit and radio wave environment in Hiraiso is getting worse. So, we have developed a new solar radio telescope in Yamagawa radio observation facility, NICT. The frequency range and time resolution in the system is 70MHz to 9.0GHz and 8 msec. In this presentation, we introduce status in progress for our new solar radio telescope.

  2. Daniel K. Inouye Solar Telescope (DKIST) Critical Science Plan

    Science.gov (United States)

    Rast, Mark

    2015-08-01

    The Daniel K. Inouye Solar Telescope (DKIST), formerly the Advanced Technology Solar Telescope (ATST), is under construction on Haleakala, Maui HI, with expected instrument integration in 2018 and start of operations during the summer of 2019. In preparation, the National Solar Observatory (NSO) is working with the Science Working Group to formulate a critical science plan for early operations and is calling for community involvement in all stages of its development. The first step in this process is the definition of a set of critical science themes and, under each of these, use-cases that outline the scientific motivation along with the instrument suite and high level observing strategies to be employed. The use-cases will later be refined into observing proposals, which will guide the development of efficient operations tools and procedures and provide the framework for some of the first science observations to be made with the telescope. A web interface has been established to facilitate community engagement.

  3. Mirror seeing control of large infrared solar telescope

    Science.gov (United States)

    Zhang, Haiying; Li, Xinnan; Meng, Xiaohui; Ni, Houkun

    2010-07-01

    To obtain high resolution infrared image, both low photon efficiency and long wavelength of infrared light requires enough large aperture telescope, but large aperture vacuum windows can hardly achieve high optical quality, so open structure becomes the only viable choice for large infrared solar telescope. In addition to the effects of atmospheric turbulence, open solar telescopes suffer from the heating of the optics by sunlight, especially primary mirror heating. These factors cause the image to shiver and become blurred, and increase infrared observing noise. Since blowing air across the front surface of the primary mirror doesn't have the necessary heat transfer coefficient to remove the absorbed heat load, it must be cooled down to maintained at a temperature between 0K and 2K below ambient air temperature to reduce the effects of turbulence. This paper will introduce some cooling methods and simulation results of primary mirror in large infrared solar telescope. On the other hand, mirror material with nice thermal conductivity can reduce the temperature difference between mirror surface and air, and mirror surface polishing at infrared wavelength can be comparatively easier than at visible wavelength, so it is possible to select low cost metal mirror as primary mirror of infrared solar telescope. To analyze the technical feasibility of metal mirror serving as primary mirror, this paper also give some polishing results of aluminum mirror with electroless nickel coating.

  4. Ultrasensitive Searches for the Axion

    Energy Technology Data Exchange (ETDEWEB)

    van Bibber, K A; Rosenberg, L J

    2006-07-14

    The axion, a hypothetical elementary particle arising from a compelling solution to the strong-CP problem, has eluded discovery for three decades. Experiments based on coherent axion-photon mixing in strong magnetic fields are just now reaching the sensitivity to detect it, either as the dark matter or as a component of the solar flux. Although of lower sensitivity, purely laboratory experiments hold potential for surprise.

  5. Sensitivity of the CUORE detector to 14.4 keV solar axions emitted by the M1 nuclear transition of 57Fe

    Science.gov (United States)

    Li, Dawei; Creswick, Richard J.; Avignone, Frank T., III; Wang, Yuanxu

    2016-02-01

    In this paper we present a calculation of the sensitivity of the CUORE detector to the monoenergetic 14.4 keV solar axions emitted by the M1 nuclear transition of 57Fe in the Sun and detected by inverse coherent Bragg-Primakoff conversion in single-crystal TeO2 bolometers. The expected counting rate is calculated using density functional theory for the electron charge density of TeO2 and realistic background and energy resolution of CUORE. Monte Carlo simulations for 5y × 741 kg=3705 kg y of exposure are analyzed using time correlation of individual events with the theoretical time-dependent counting rate. We find an expected model-independent limit on the product of the axion-photon coupling and the axion-nucleon coupling gaγγgaNeff < 1.105 × 10-16 /GeV for axion masses less than 500 eV with 95% confidence level.

  6. Sensitivity of the CUORE detector to $14.4$ keV solar axions emitted by the M1 nuclear transition of$~^{57}$Fe

    CERN Document Server

    Li, Dawei; Avignone, Frank T; Wang, Yuanxu

    2015-01-01

    In this paper we present a calculation of the sensitivity of the CUORE detector to the monoenergetic $14.4$ keV solar axions emitted by the M1 nuclear transition of$~^{57}$Fe in the Sun and detected by inverse coherent Bragg-Primakoff conversion in single-crystal $TeO_2$ bolometers. The expected counting rate is calculated using density functional theory for the electron charge density of $TeO_2$ and realistic background and energy resolution of CUORE. Monte Carlo simulations for $5$ y $\\times$ $741$ kg=$3705-$kg$\\cdot$y of exposure are analyzed using time correlation of individual events with the theoretical time-dependent counting rate. We find an expected model-independent limit on the product of the axion-photon coupling and the axion-nucleon coupling $g_{a\\gamma\\gamma}\\{|-1.19g^0_{aN}+g^3_{aN}|\\}<1.105\\times 10^{-16}$ /GeV for axion masses less than 500 eV with $95\\%$ confidence level.

  7. Spectropolarimetry with CRISP at the Swedish 1-m Solar Telescope

    OpenAIRE

    Ortiz, A.; van der Voort, L. H. M. Rouppe

    2009-01-01

    CRISP (Crisp Imaging Spectro-polarimeter), the new spectropolarimeter at the Swedish 1-m Solar Telescope, opens a new perspective in solar polarimetry. With better spatial resolution (0.13") than Hinode in the Fe I 6302 A line and similar polarimetric sensitivity reached through postprocessing, CRISP complements the SP spectropolarimeter onboard Hinode. We present some of the data which we obtained in our June 2008 campaign and preliminary results from LTE inversions of a pore containing umbr...

  8. Rotating Drops of Axion Dark Matter

    CERN Document Server

    Davidson, Sacha

    2016-01-01

    We consider how QCD axions produced by the misalignment mechanism could form galactic dark matter halos. We recall that stationary, gravitationally stable axion field configurations have the size of an asteroid with masses of order $10^{-13} $ solar masses (because gradient pressure is insufficient to support a larger object). We call such field configurations "drops". We explore whether rotating drops could be larger, and find that their mass could increase by a factor ~ 10. Remarkably this mass is comparable to the mass of miniclusters generated from misalignment axions in the scenario where the axion is born after inflation. We speculate that misalignment axions today are in the form of drops, contributing to dark matter like a distribution of asteroids (and not as a coherent oscillating background field). We consider some observational signatures of the drops, which seem consistent with a galactic halo made of axion dark matter.

  9. Axion Cosmology

    OpenAIRE

    Ringwald, A.

    2012-01-01

    In this master's thesis we study the cosmological consequences of the new scalar field, the axion, that appears in the U(1)_PQ extension of the standard model of particle physics. We start by presenting some essential fragments of the standard model of Big Bang cosmology, that are needed when we describe the evolution of the axion field in the early Universe. We also review the basics of phase transitions in the early Universe, and go through the creation and evolution of the topological defe...

  10. Search for solar axion emission from $^7$Li and D(p,$\\gamma)^3$He nuclear decays with the CAST $\\gamma$-ray calorimeter

    CERN Document Server

    Andriamonje, S; Autiero, D; Barth, K; Belov, A; Beltran, B; Brauninger, H; Carmona, J M; Cebrian, S; Collar, J I; Dafni, T; Davenport, M; Di Lella, L; Eleftheriadis, C; Englhauser, J; Fanourakis, G; Ferrer-Ribas, E; Fischer, H; Franz, J; Friedrich, P; Geralis, T; Giomataris, I; Gninenko, S; Gomez, H; Hasinoff, M; Heinsius, F H; Hoffmann, D.H H; Irastorza, I G; Jacoby, J; Jakovcic, K; Kang, D; Konigsmann, K; Kotthaus, R; Krcmar, M; Kousouris, K; Kuster, M; Lakic, B; Lasseur, C; Liolios, A; Ljubicic, A; Lutz, G; Luzon, G; Miller, D W; Morales, J; Ortiz, A; Papaevangelou, T; Placci, A; Raffelt, G; Riege, H; Rodriguez, A; Ruz, J; Savvidis, I; Semertzidis, Y; Serpico, P; Stewart, L; Vieira, J D; Villar, J; Vogel, J; Walckiers, L; Zioutas, K

    2010-01-01

    We present the results of a search for a high-energy axion emission signal from 7Li (0.478 MeV) and D(p,gamma)3He (5.5 MeV) nuclear transitions using a low-background gamma-ray calorimeter during Phase I of the CAST experiment. These so-called "hadronic axions" could provide a solution to the long-standing strong-CP problem and can be emitted from the solar core from nuclear M1 transitions. This is the first such search for high-energy pseudoscalar bosons with couplings to nucleons conducted using a helioscope approach. No excess signal above background was found.

  11. Conceptual design of the International Axion Observatory (IAXO)

    DEFF Research Database (Denmark)

    Armengaud, E.; Avignone, F. T.; Betz, M.;

    2014-01-01

    The International Axion Observatory (IAXO) will be a forth generation axion helioscope. As its primary physics goal, IAXO will look for axions or axion-like particles (ALPs) originating in the Sun via the Primakoff conversion of the solar plasma photons. In terms of signal-to-noise ratio, IAXO will...... be about 4–5 orders of magnitude more sensitive than CAST, currently the most powerful axion helioscope, reaching sensitivity to axion-photon couplings down to a few × 10−12 GeV−1 and thus probing a large fraction of the currently unexplored axion and ALP parameter space. IAXO will also be sensitive...... and ALP research in the next decade. In this paper we present the conceptual design of IAXO, which follows the layout of an enhanced axion helioscope, based on a purpose-built 20 m-long 8-coils toroidal superconducting magnet. All the eight 60cm-diameter magnet bores are equipped with focusing x...

  12. Modeling the electron-proton telescope on Solar Orbiter

    International Nuclear Information System (INIS)

    The Electron Proton Telescope (EPT) is one of four sensors in the Energetic Particle Detector suite for Solar Orbiter. It investigates low energy electrons and protons of solar events in an energy range from 20 - 400 keV for electrons and 20 keV - 7 MeV for protons. It distinguishes electrons from protons using a magnet/foil technique with silicon detectors. There will be two EPT units, each with double-barreled telescopes, one looking sunwards/antisunwards and the other north/south. We set up a Monte Carlo model of EPT using the GEANT4 framework, which we can use to simulate interactions of energetic particles in the sensor. Here we present simulation results of the energy coverage for different ion species, and we study how it is possible to distinguish between them.

  13. Solar System Observations with the James Webb Space Telescope

    Science.gov (United States)

    Norwood, James; Hammel, Heidi; Milam, Stefanie; Stansberry, John; Lunine, Jonathan; Chanover, Nancy; Hines, Dean; Sonneborn, George; Tiscareno, Matthew; Brown, Michael; Ferruit, Pierre

    2016-02-01

    The James Webb Space Telescope (JWST) will enable a wealth of new scientific investigations in the near- and mid-infrared, with sensitivity and spatial/spectral resolution greatly surpassing its predecessors. In this paper, we focus upon Solar System science facilitated by JWST, discussing the most current information available concerning JWST instrument properties and observing techniques relevant to planetary science. We also present numerous example observing scenarios for a wide variety of Solar System targets to illustrate the potential of JWST science to the Solar System community. This paper updates and supersedes the Solar System white paper published by the JWST Project in 2010. It is based both on that paper and on a workshop held at the annual meeting of the Division for Planetary Sciences in Reno, NV, in 2012.

  14. Axions from the Earth

    International Nuclear Information System (INIS)

    The possibility of axion production in the Earth's interior due to natural radioactive decay is considered. Axions, or axion-like particles, could be created in nuclear disintegrations and deexitations of natural radionuclides present in the Earth's crust and mantle, as well as due to photon to axion conversion of the emitted gamma rays via the Primakoff effect. The estimated geo-axion production rates and fluxes on the Earth's surface are given along with the axion coupling to ordinary matter in the frame of the simple axion models as well as for axion-like particles with stronger couplings

  15. On the co-alignment of solar telescopes. A new approach to solar pointing

    International Nuclear Information System (INIS)

    Helioseismological measurements require long observing times and thus may be adversely affected by lateral image drifts as caused by pointing instabilities. At the Vacuum Tower Telescope VTT, Tenerife we have recorded drift values of up to 5'' per hour under unstable thermal conditions (dome opening, strong day-to-day thermal gradients). Typically drifts of 0.5'' – 1.0'' per hour may be encountered under more favorable conditions. Past experience has shown that most high-resolution solar telescopes may be affected by this problem to some degree. This inherent shortcoming of solar pointing is caused by the fact that the guiding loop can be closed only within the guiding beam but not within the telescope's main beam. We have developed a new approach to this problem. We correlate continuum brightness patterns observed from within the telescope main beam with patterns originating from a full disk telescope. We show that brightness patterns of sufficient size are unique with respect to solar location at any instant of time and may serve as a location identifier. We make use of the fact that averaged location information of solar structures is invariant with respect to telescope resolution. We have carried out tests at the VTT together with SDO. We have used SDO as a full disk reference. We were able to reduce lateral image drifts by an order of magnitude.

  16. On the co-alignment of solar telescopes. A new approach to solar pointing

    Science.gov (United States)

    Staiger, J.

    2013-06-01

    Helioseismological measurements require long observing times and thus may be adversely affected by lateral image drifts as caused by pointing instabilities. At the Vacuum Tower Telescope VTT, Tenerife we have recorded drift values of up to 5" per hour under unstable thermal conditions (dome opening, strong day-to-day thermal gradients). Typically drifts of 0.5" - 1.0" per hour may be encountered under more favorable conditions. Past experience has shown that most high-resolution solar telescopes may be affected by this problem to some degree. This inherent shortcoming of solar pointing is caused by the fact that the guiding loop can be closed only within the guiding beam but not within the telescope's main beam. We have developed a new approach to this problem. We correlate continuum brightness patterns observed from within the telescope main beam with patterns originating from a full disk telescope. We show that brightness patterns of sufficient size are unique with respect to solar location at any instant of time and may serve as a location identifier. We make use of the fact that averaged location information of solar structures is invariant with respect to telescope resolution. We have carried out tests at the VTT together with SDO. We have used SDO as a full disk reference. We were able to reduce lateral image drifts by an order of magnitude.

  17. Axionic membranes

    Energy Technology Data Exchange (ETDEWEB)

    Aurilia, A. (Dept. of Physics, California State Polytechnic Univ., Pomona, CA (United States)); Spallucci, E. (Dipt. di Fisica Teorica, Univ. Trieste (Italy) INFN, Sezione Trieste (Italy))

    1992-05-21

    A metal ring removed from a soap-water solution encloses a film of soap which can be mathematically described as a minimal surface having the ring as its only boundary. This is known to everybody. In this letter we suggest a relativistic extension of the above fluidodynamic system where the soap film is replaced by a Kalb-Ramand gauge potential B{sub {mu}{nu}}(x) and the ring by a closed string. The interaction between the B{sub {mu}{nu}} field and the string current excites a new configuration of the system consisting of a relativistic membrane bounded by the string. We call such a classical solution of the equation of motion an axionic membrane. As a dynamical system, the axionic membrane admits a Hamilton-Jacobi formulation which is an extension of the HJ theory of electromagnetic strings. (orig.).

  18. Ultrasensitive searches for the axion

    CERN Multimedia

    Van Bibber, Karl

    2006-01-01

    "The axion is a hypothetical particle with a mass possibly a trillion times lighter than an electron and exceedingly small couplings to ordinary matter. Yet experiments may soon detect its presence, either as dark matter or as a component of solar flux." (6 pages)

  19. Surveying the Inner Solar System with an Infrared Space Telescope

    OpenAIRE

    Buie, Marc W.; Reitsema, Harold J.; Linfield, Roger P.

    2016-01-01

    We present an analysis of surveying the inner Solar System for objects that may pose some threat to the Earth. Most of the analysis is based on understanding the capability provided by Sentinel, a concept for an infrared space-based telescope placed in a heliocentric orbit near the distance of Venus. From this analysis, we show 1) the size range being targeted can affect the survey design, 2) the orbit distribution of the target sample can affect the survey design, 3) minimum observational ar...

  20. Solar System Observing Capabilities With The James Webb Space Telescope

    Science.gov (United States)

    Sonneborn, George; Milam, S. N.; Hines, D. C.; Stansberry, J. A.; Hammel, H. B.; Lunine, J. I.

    2014-01-01

    The James Webb Space Telescope (JWST) will provide important new capabilities to study our Solar System. JWST is a large aperture, cryogenic, infrared-optimized space observatory under construction by NASA, ESA, and CSA for launch in 2018 into a L2 orbit. Imaging, spectroscopy, and coronography covers 0.6-29 microns. Integral-field spectroscopy is performed with apertures 3 to 7 arcsec square (spatial slices of 0.1 to 0.6 arcsec). JWST is designed to observe Solar System objects having apparent rates of motion up to 0.030 arcseconds/second. This tracking capability includes the planets, satellites, asteroids, Trans-Neptunian Objects, and comets beyond Earth’s orbit. JWST will observe in the solar elongation range of 85 to 135 degrees, and a roll range of +/-5 degrees about the telescope’s optical axis. During an observation of a moving target, the science target is held fixed in the desired science aperture by controlling the guide star to follow the inverse of the target’s trajectory. The pointing control software uses polynomial ephemerides for the target generated using data from JPL’s HORIZON system. The JWST guider field of view (2.2x2.2 arcmin) is located in the telescope focal plane several arcmin from the science apertures. The instrument apertures are fixed with respect to the telescope focal plane. For targets near the ecliptic, those apertures also have a nearly fixed orientation relative to the ecliptic. This results from the fact that the Observatory's sunshield and solar panels must always be between the telescope and the Sun. On-board scripts autonomously control the execution of the JWST science timeline. The event-driven scripts respond to actual slew and on-board command execution, making operations more efficient. Visits are scheduled with overlapping windows to provide execution flexibility and to avoid lost time. An observing plan covering about ten days will be uplinked weekly. Updates could be more frequent if necessary (for example

  1. Low background x-ray detection with Micromegas for axion research

    CERN Document Server

    Aune, S; Dafni, T; Davenport, M; Fanourakis, G; Ferrer-Ribas, E; Galan, J; Garcia, J A; Gardikiotis, A; Geralis, T; Giomataris, I; Gomez, H; Garza, J G; Herrera, D C; Iguaz, F J; Irastorza, I G; Jourde, D; Luzon, G; Mols, J P; Papaevangelou, T; Rodriguez, A; Ruz, J; Segui, L; Tomas, A; Vafeiadis, T; Yildiz, S C

    2014-01-01

    Axion helioscopes aim at the detection of solar axions through their conversion into x-rays in laboratory magnetic fields. The use of low background x-ray detectors is an essential component contributing to the sensitivity of these searches. Here we review the recent advances on Micromegas detectors used in the CERN Axion Solar Telescope (CAST) and proposed for the future International Axion Observatory (IAXO). The most recent Micromegas setups in CAST have achieved background levels of 1.5$\\times10^{-6}$\\ckcs, a factor of more than 100 lower than the ones obtained by the first generation of CAST detectors. This improvement is due to the development of active and passive shielding techniques, offline discrimination techniques allowed by highly granular readout patterns, as well as the use of radiopure detector components. The status of the intensive R&D to reduce the background levels will be described, including the operation of replica detectors in test benches and the detailed Geant4 simulation of the ...

  2. Low background x-ray detection with Micromegas for axion research

    International Nuclear Information System (INIS)

    Axion helioscopes aim at the detection of solar axions through their conversion into x-rays in laboratory magnetic fields. The use of low background x-ray detectors is an essential component contributing to the sensitivity of these searches. Here we review the recent advances on Micromegas detectors used in the CERN Axion Solar Telescope (CAST) and proposed for the future International Axion Observatory (IAXO). The most recent Micromegas setups in CAST have achieved background levels of 1.5 × 10−6 keV−1 cm−2 s−1, a factor of more than 100 lower than the ones obtained by the first generation of CAST detectors. This improvement is due to the development of active and passive shielding techniques, offline discrimination techniques allowed by highly granular readout patterns, as well as the use of radiopure detector components. The status of the intensive R and D to reduce the background levels will be described, including the operation of replica detectors in test benches and the detailed Geant4 simulation of the detector setup and the detector response, which has allowed the progressive understanding of background origins. The best levels currently achieved in a test setup operating in the Canfranc Underground Laboratory (LSC) are as low as ∼ 10−7 keV−1 cm−2 s−1, showing the good prospects of this technology for application in the future IAXO

  3. The feasibility of large refracting telescopes for solar coronal research

    Science.gov (United States)

    Nelson, Peter G.; Tomczyk, Steven; Elmore, David F.; Kolinski, Donald J.

    2008-07-01

    Measuring magnetic fields in the solar corona requires a large aperture telescope with exceptionally low levels of scattered light. For internally-occulted coronagraphs the main source is scattering from dust or microroughness on the primary lens or mirror. We show refracting primaries offer significantly lower levels for both sources. To observe magnetic fields in the solar corona with scientifically interesting spatial and temporal resolutions, a 1 meter aperture or larger is required. For a long time such large-scale refractors have been deemed impractical or impossible to construct due to gravitational deformation of the lens. We present the results of finite-element and optical analyses of the gravitational deformation, stress-induced birefringence, and absorptive heating of a (see manuscript)1.5 meter f/5 fused silica lens. These studies demonstrate the traditional objections to large refractors are unfounded and large refracting primaries have unique capabilities.

  4. A New Multi-wavelength Solar Telescope: Optical and Near-infrared Solar Eruption Tracer (ONSET)

    OpenAIRE

    Fang, C.; Chen, P. F.; Li, Z.; Ding, M. D.; Dai, Y.; X. Y. Zhang; Mao, W. J.; J. P. Zhang; T. Li; Liang, Y J; Lu, H T

    2013-01-01

    A new multi-wavelength solar telescope, Optical and Near-infrared Solar Eruption Tracer (ONSET) of Nanjing University, was constructed, being fabricated by Nanjing Institute of Astronomical Optics & Technology and run in cooperation with Yunnan Astronomical Observatory. ONSET is able to observe the Sun in three wavelength windows: He {\\small I} 10830 \\AA, H$\\alpha$, and white-light at 3600 \\AA and 4250 \\AA, which are selected in order to obtain the dynamics in the corona, chromosphere, and th...

  5. Dense Axion Stars

    CERN Document Server

    Braaten, Eric; Zhang, Hong

    2015-01-01

    If the dark matter consists of axions, gravity can cause them to coalesce into axion stars, which are stable gravitationally bound Bose-Einstein condensates of axions. In the previously known axion stars, gravity and the attractive force between pairs of axions are balanced by the kinetic pressure.If the axion mass energy is $mc^2= 10^{-4}$ eV, these dilute axion stars have a maximum mass of about $10^{-14} M_\\odot$. We point out that there are also dense axion stars in which gravity is balanced by the mean-field pressure of the axion condensate. We study axion stars using the leading term in a systematically improvable approximation to the effective potential of the nonrelativistic effective field theory for axions. Using the Thomas-Fermi approximation in which the kinetic pressure is neglected, we find a sequence of new branches of axion stars in which gravity is balanced by the mean-field interaction energy of the axion condensate. If $mc^2 = 10^{-4}$ eV, the first branch of these dense axion stars has mas...

  6. Conceptual Design of the International Axion Observatory (IAXO)

    CERN Document Server

    Armengaud, E; Betz, M; Brax, P; Brun, P; Cantatore, G; Carmona, J M; Carosi, G P; Caspers, F; Caspi, S; Cetin, S A; Chelouche, D; Christensen, F E; Dael, A; Dafni, T; Davenport, M; Derbin, A V; Desch, K; Diago, A; Döbrich, B; Dratchnev, I; Dudarev, A; Eleftheriadis, C; Fanourakis, G; Ferrer-Ribas, E; Galán, J; García, J A; Garza, J G; Geralis, T; Gimeno, B; Giomataris, I; Gninenko, S; Gómez, H; González-Díaz, D; Guendelman, E; Hailey, C J; Hiramatsu, T; Hoffmann, D H H; Horns, D; Iguaz, F J; Irastorza, I G; Isern, J; Imai, K; Jakobsen, A C; Jaeckel, J; Jakovčić, K; Kaminski, J; Kawasaki, M; Karuza, M; Krčmar, M; Kousouris, K; Krieger, C; Lakić, B; Limousin, O; Lindner, A; Liolios, A; Luzón, G; Matsuki, S; Muratova, V N; Nones, C; Ortega, I; Papaevangelou, T; Pivovaroff, M J; Raffelt, G; Redondo, J; Ringwald, A; Russenschuck, S; Ruz, J; Saikawa, K; Savvidis, I; Sekiguchi, T; Semertzidis, Y K; Shilon, I; Sikivie, P; Silva, H; Kate, H ten; Tomas, A; Troitsky, S; Vafeiadis, T; Bibber, K van; Vedrine, P; Villar, J A; Vogel, J K; Walckiers, L; Weltman, A; Wester, W; Yildiz, S C; Zioutas, K

    2014-01-01

    The International Axion Observatory (IAXO) will be a forth generation axion helioscope. As its primary physics goal, IAXO will look for axions or axion-like particles (ALPs) originating in the Sun via the Primakoff conversion of the solar plasma photons. In terms of signal-to-noise ratio, IAXO will be about 4-5 orders of magnitude more sensitive than CAST, currently the most powerful axion helioscope, reaching sensitivity to axion-photon couplings down to a few $\\times 10^{-12}$ GeV$^{-1}$ and thus probing a large fraction of the currently unexplored axion and ALP parameter space. IAXO will also be sensitive to solar axions produced by mechanisms mediated by the axion-electron coupling $g_{ae}$ with sensitivity $-$for the first time$-$ to values of $g_{ae}$ not previously excluded by astrophysics. With several other possible physics cases, IAXO has the potential to serve as a multi-purpose facility for generic axion and ALP research in the next decade. In this paper we present the conceptual design of IAXO, w...

  7. Multiple-etalon systems for the Advanced Technology Solar Telescope

    Science.gov (United States)

    Gary, G. Allen; Balasubramaniam, K. S.; Sigwarth, Michael

    2003-01-01

    Multiple etalon systems are discussed that meet the science requirements for a narrow-passband imaging system for the 4-meter National Solar Observatory (NSO)/Advance Technology Solar Telescope (ATST). A multiple etalon system can provide an imaging interferometer that works in four distinct modes: as a spectro-polarimeter, a filter-vector magnetograph, an intermediate-band imager, and broadband high-resolution imager. Specific dual and triple etalon configurations are described that provide a spectrographic passband of 2.0-3.5 micron and reduce parasitic light levels to 10(exp -4) as required for precise polarization measurement, e.g., Zeeman measurements of magnetic sensitive lines. A TESOS-like (Telecentric Etalon SOlar Spectrometer) triple etalon system provides a spectral purity of 10(exp -5). The triple designs have the advantage of reducing the finesse requirement on each etalon; allow the use of more stable blocking filters, and have very high spectral purity. A dual-etalon double-pass (Cavallini-like) system can provide a competing configuration. Such a dual-etalon design can provide high contrast. The selection of the final focal plane instrument will depend on a trade-off between an ideal instrument and practical reality. The trade study will include the number of etalons, their aperture sizes, complexities of the optical train, number of blocking filters, configuration of the electronic control system, computer interfaces, temperature controllers, etalon controllers, and their associated feedback electronics. The heritage of single and multiple etalon systems comes from their use in several observatories, including the Marshall Space Flight Center (MSFC) Solar Observatory, Sacramento Peak Observatory (NSO), and Kiepenheuer-Institut fur Sonnenphysik (KIS, Germany), Mees Solar Observatory (University of Hawaii), and Arcetri Astrophysical Observatory (Italy). The design of the ATST multiple etalon system will benefit from the experience gained at these

  8. Multiple Etalon Systems for the Advanced Technology Solar Telescope

    Science.gov (United States)

    Gary, G. Allen; Balasubramaniam, K. S.; Sigwarth, Michael; Six, N. Frank (Technical Monitor)

    2002-01-01

    Multiple etalons systems are discussed that meet the 4-meter NSO/Advance Technology Solar Telescope (http://www.nso.edu/ATST/index.html) instrument and science requirements for a narrow bandpass imaging system. A multiple etalon system can provide an imaging interferometer working in four distinct modes: as a spectro-polarimeter, a filter-vector magnetograph, and a wide-band and broad-band high-resolution imager. Specific dual and triple etalon configurations will be described that provides spectrographic passband of 2.0-3.5nm and reduces parasitic light levels to 1/10000 as required by precise polarization measurement, e.g., Zeeman measurements of magnetic sensitive lines. A TESOS-like triple etalon system provides for spectral purity of 100 thousandths. The triple designs have the advantage of reducing the finesse requirement on each etalon, allowing much more stable blocking filters, and can have very high spectral purity. A dual-etalon double-pass Cavallini-like configuration can provide a competing configuration. This design can provide high contrast with only a double etalon. The selection of the final focal plan instrument will depend on a trade-off of the ideal instrument versus reality, the number of etalons, the aperture of etalons, the number of blocking filters the electronic control system and computer interfaces, the temperature control and controllers for the etalons and the electronics. The use of existing experience should provide significant cost savings. The heritage of use of etalons and multiple etalon systems in solar physics come from a number of observatories, which includes MSFC Solar Observatory (NASA), Sac Peak Observatory (NSO), and Kiepenheuer Institute for Solar Physics (Germany), Mees Solar Observatory (University of Hawaii), and Arcetri Astrophysical Observatory (Italy). The design of the ATST multiple etalon system will reply on the existing experience from these observatories.

  9. Telescoping Solar Array Concept for Achieving High Packaging Efficiency

    Science.gov (United States)

    Mikulas, Martin; Pappa, Richard; Warren, Jay; Rose, Geoff

    2015-01-01

    Lightweight, high-efficiency solar arrays are required for future deep space missions using high-power Solar Electric Propulsion (SEP). Structural performance metrics for state-of-the art 30-50 kW flexible blanket arrays recently demonstrated in ground tests are approximately 40 kW/cu m packaging efficiency, 150 W/kg specific power, 0.1 Hz deployed stiffness, and 0.2 g deployed strength. Much larger arrays with up to a megawatt or more of power and improved packaging and specific power are of interest to mission planners for minimizing launch and life cycle costs of Mars exploration. A new concept referred to as the Compact Telescoping Array (CTA) with 60 kW/cu m packaging efficiency at 1 MW of power is described herein. Performance metrics as a function of array size and corresponding power level are derived analytically and validated by finite element analysis. Feasible CTA packaging and deployment approaches are also described. The CTA was developed, in part, to serve as a NASA reference solar array concept against which other proposed designs of 50-1000 kW arrays for future high-power SEP missions could be compared.

  10. Investigation of Umbral Dots with the New Vacuum Solar Telescope

    CERN Document Server

    Kaifan, Ji; Song, Feng; Yunfei, Yang; Hui, Deng; Feng, Wang

    2015-01-01

    Umbral dots (UDs) are small isolated brightening observed in sunspot umbrae. They are convective phenomena existing inside umbrae. UDs are usually divided into central UDs (CUDs) and peripheral UDs (PUDs) with respect to their positions inside an umbra. Our purpose is to investigate UD properties and analyze their relationships, and further to find whether or not the properties depend on the umbral magnetic field variation. For the purpose, we selected the high-resolution TiO images of four active regions (ARs) obtained under the best seeing conditions with the \\emph{New Vacuum Solar Telescope} (NVST) in Fuxian Solar Observatory of Yunnan Astronomical Observatory, China. The four ARs (NOAA 11598, 11801, 12158, and 12178) include six sunspots. A total of 1220 CUDs were extracted from six sunspots, and 603 PUDs from three sunspots. Meanwhile, the radial component of the magnetic field of the sunspots obtained with the \\emph{Helioseismic and Magnetic Imager} onboard the \\emph{Solar Dynamics Observatory} was used...

  11. The X-ray Telescope of CAST

    CERN Document Server

    Kuster, M; Cebrián, S; Davenport, M; Elefteriadis, C; Englhauser, J; Fischer, H; Franz, J; Friedrich, P; Hartmann, R; Heinsius, F H; Hoffmann, Dieter H H; Hoffmeister, G; Joux, J N; Königsmann, K C; Kang, D; Kotthaus, R; Lasseur, C; Lippitsch, A; Lutz, G; Morales, J; Papaevangelou, T; Rodríguez, A; Strüder, L; Vogel, J; Zioutas, K

    2007-01-01

    The Cern Axion Solar Telescope (CAST) is in operation and taking data since 2003. The main objective of the CAST experiment is to search for a hypothetical pseudoscalar boson, the axion, which might be produced in the core of the sun. The basic physics process CAST is based on is the time inverted Primakoff effect, by which an axion can be converted into a detectable photon in an external electromagnetic field. The resulting X-ray photons are expected to be thermally distributed between 1 and 7 keV. The most sensitive detector system of CAST is a pn-CCD detector combined with a Wolter I type X-ray mirror system. With the X-ray telescope of CAST a background reduction of more than 2 orders off magnitude is achieved, such that for the first time the axion photon coupling constant g_agg can be probed beyond the best astrophysical constraints g_agg < 1 x 10^-10 GeV^-1.

  12. Thermal analysis of the main mirror in space solar telescope

    Science.gov (United States)

    Li, Rong; Shi, Hu-li; Chen, Zhi-yuan

    2007-12-01

    For the design of a space solar telescope (SST), the large reflect mirror faces to the sun directly, which is in an abominable thermal condition with seriously thermal distortion. In this paper, it sets up the thermal mode and analyzes the temperature field and thermal distortion of the main mirror of SST. Further more, it uses the thermal design software SINDA/G (System Improved Numerical Differencing Analyzer/Gaski) and the finite element analysis software MSC.Patran to set up different models and various temperature distributions of the main mirror. Though comparing with these models, the paraboloid mirror model is confirmed, which becomes a reference to later thermal analysis of the whole SST.

  13. Axion Cooling of Neutron Stars

    CERN Document Server

    Sedrakian, Armen

    2015-01-01

    Cooling simulations of neutron stars and their comparison with the data from thermally emitting X-ray sources puts constraints on the properties of axions, and by extension of any light pseudo-scalar dark matter particles, whose existence has been postulated to solve the strong-CP problem of QCD. We incorporate the axion emission by pair-breaking and formation processes by $S$- and $P$-wave nucleonic condensates in a benchmark code for cooling simulations as well as provide fit formulae for the rates of these processes. Axion cooling of neutron stars has been simulated for 24 models covering the mass range 1 to 1.8 solar masses, featuring non-accreted iron and accreted light element envelopes, and a range of nucleon-axion coupling. The models are based on an equation state predicting conservative physics of superdense nuclear matter that does not allow for onset of fast cooling processes induced by phase transitions to non-nucleonic forms of matter or high proton concentration. The cooling tracks in the tempe...

  14. A new multi-wavelength solar telescope: Optical and Near-infrared Solar Eruption Tracer (ONSET)

    International Nuclear Information System (INIS)

    A new multi-wavelength solar telescope, the Optical and Near-infrared Solar Eruption Tracer (ONSET) of Nanjing University, has been constructed. It was fabricated at the Nanjing Institute of Astronomical Optics and Technology, and the operation is jointly administered with Yunnan Astronomical Observatory. ONSET is able to observe the Sun in three wavelength windows: He I 10830 Å, Hα and white-light at 3600 Å and 4250 Å, which are selected in order to simultaneously record the dynamics of the corona, chromosphere and photosphere respectively. Full-disk or partial-disk solar images with a field of 10' at three wavelengths can be obtained nearly simultaneously. It is designed to trace solar eruptions with high spatial and temporal resolutions. This telescope was installed at a new solar observing site near Fuxian Lake in Yunnan Province, southwest China. The site is located at E102N24, with an altitude of 1722 m. The seeing is stable and has high quality. We give a brief description of the scientific objectives and the basic structure of ONSET. Some preliminary results are also presented

  15. Detecting ultralight axion dark matter wind with laser interferometers

    OpenAIRE

    Aoki, Arata; Soda, Jiro

    2016-01-01

    The ultralight axion with mass around $10^{-23}$ eV is known as a candidate of dark matter. A peculiar feature of the ultralight axion is oscillating pressure in time, which produces oscillation of gravitational potentials. Since the solar system moves through the dark matter halo at the velocity of about $v \\sim 300 \\, \\text{km} / \\text{s} = 10^{-3}$, there exists axion wind, which looks like scalar gravitational waves for us. Hence, there is a chance to detect ultralight axion dark matter w...

  16. Space solar telescope in soft X-ray and EUV band

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In this paper we have reviewed our achievements in soft X-ray and extreme ultraviolet (EUV) optics. Up to now, the research system of soft X-ray and EUV optics has been established, including light sources, detectors, calibrations, optical testing and machining of super smooth mirrors, and fabrications of multilayer film mirrors. Based on our achievements, we have developed two types of solar space telescopes for the soft X-ray and EUV space solar observations. One is an EUV multilayer normal incident telescope array including 4 different operation wavelength telescopes. The operation wavelengths of the EUV telescope are 13.0, 17.1, 19.5 and 30.4 nm. The other is a complex space solar telescope, which is composed of an EUV multilayer normal incident telescope and a soft X-ray grazing incident telescope. The EUV multilayer normal incident telescope stands in the central part of the soft X-ray grazing incident telescope. The normal incident telescope and the grazing incident telescope have a common detector. The different operation wavelengths can be changed by rotating a filter wheel.

  17. Search for energetic cosmic axions utilizing terrestrial/celestial magnetic fields

    OpenAIRE

    Zioutas, K.; Thompson, D J; E. A. Paschos

    1998-01-01

    Orbiting $\\gamma$-detectors combined with the magnetic field of the Earth or the Sun can work parasitically as cosmic axion telescopes. The relatively short field lengths allow the axion-to-photon conversion to be coherent for $m_{axion} \\sim 10^{-4}$ eV, if the axion kinetic energy is above $\\sim 500$ keV (Earth's field), or, $\\sim 50$ MeV (Sun's field), allowing thus to search for axions from $e^+e^-$ annihilations, from supernova explosions, etc. With a detector angular resolution of $\\sim...

  18. Stellar axion models

    Energy Technology Data Exchange (ETDEWEB)

    Nowakowski, Daniel; Kuster, Markus; Meister, Claudia V.; Fuelbert, Florian; Hoffmann, Dieter H.H. [TU Darmstadt (Germany). Institut fuer Kernphysik; Weiss, Achim [Max-Planck-Institut fuer Astrophysik, Garching (Germany)

    2010-07-01

    An axion helioscope is typically operated to observe the sun as an axion source. Additional pointings at celestial sources, e.g. stars in other galaxies, result in possible detections of axions from distant galactic objects. For the observation of supplementary axion sources we therefore calculate the thereotical axion flux from distant stars by extending axionic flux models for the axion Primakoff effect in the sun to other main sequence stars. The main sequence star models used for our calculations are based on full stellar structure calculations. To deduce the effective axion flux of stellar objects incident on the Earth the All-Sky catalogue was used to obtain the spectral class and distance of the stars treated. Our calculations of the axion flux in the galactic plane show that for a zero age main sequence star an maximum axion flux of {phi}{sub a}=303.43 cm{sup -2}s{sup -1} could be expected. Furthermore we present estimates of axion fluxes from time-evolved stars.

  19. Stellar axion models

    International Nuclear Information System (INIS)

    An axion helioscope is typically operated to observe the sun as an axion source. Additional pointings at celestial sources, e.g. stars in other galaxies, result in possible detections of axions from distant galactic objects. For the observation of supplementary axion sources we therefore calculate the thereotical axion flux from distant stars by extending axionic flux models for the axion Primakoff effect in the sun to other main sequence stars. The main sequence star models used for our calculations are based on full stellar structure calculations. To deduce the effective axion flux of stellar objects incident on the Earth the All-Sky catalogue was used to obtain the spectral class and distance of the stars treated. Our calculations of the axion flux in the galactic plane show that for a zero age main sequence star an maximum axion flux of Φa=303.43 cm-2s-1 could be expected. Furthermore we present estimates of axion fluxes from time-evolved stars.

  20. Solar System science with the Large Synoptic Survey Telescope

    Science.gov (United States)

    Jones, Lynne; Brown, Mike; Ivezić, Zeljko; Jurić, Mario; Malhotra, Renu; Trilling, David

    2015-11-01

    The Large Synoptic Survey Telescope (LSST; http://lsst.org) will be a large-aperture, wide-field, ground-based telescope that will survey half the sky every few nights in six optical bands from 320 to 1050 nm. It will explore a wide range of astrophysical questions, ranging from performing a census of the Solar System, to examining the nature of dark energy. It is currently in construction, slated for first light in 2019 and full operations by 2022.The LSST will survey over 20,000 square degrees with a rapid observational cadence, to typical limiting magnitudes of r~24.5 in each visit (9.6 square degree field of view). Automated software will link the individual detections into orbits; these orbits, as well as precisely calibrated astrometry (~50mas) and photometry (~0.01-0.02 mag) in multiple bandpasses will be available as LSST data products. The resulting data set will have tremendous potential for planetary astronomy; multi-color catalogs of hundreds of thousands of NEOs and Jupiter Trojans, millions of asteroids, tens of thousands of TNOs, as well as thousands of other objects such as comets and irregular satellites of the major planets.LSST catalogs will increase the sample size of objects with well-known orbits 10-100 times for small body populations throughout the Solar System, enabling a major increase in the completeness level of the inventory of most dynamical classes of small bodies and generating new insights into planetary formation and evolution. Precision multi-color photometry will allow determination of lightcurves and colors, as well as spin state and shape modeling through sparse lightcurve inversion. LSST is currently investigating survey strategies to optimize science return across a broad range of goals. To aid in this investigation, we are making a series of realistic simulated survey pointing histories available together with a Python software package to model and evaluate survey detections for a user-defined input population. Preliminary

  1. Lowering the background level and the energy threshold of Micromegas x-ray detectors for axion searches

    CERN Document Server

    Iguaz, F J; Aznar, F; Castel, J F; Dafni, T; Davenport, M; Ferrer-Ribas, E; Galan, J; Garcia, J A; Garza, J G; Giomataris, I; Irastorza, I G; Papaevangelou, T; Rodriguez, A; Tomas, A; Vafeiadis, T; Yildiz, S C

    2014-01-01

    Axion helioscopes search for solar axions by their conversion in x-rays in the presence of high magnetic fields. The use of low background x-ray detectors is an essential component contributing to the sensitivity of these searches. In this work, we review the recent advances on Micromegas detectors used in the CERN Axion Solar Telescope (CAST) and proposed for the future International Axion Observatory (IAXO). The actual setup in CAST has achieved background levels below 10$^{-6}$ keV$^{-1}$ cm$^{-2}$ s$^{-1}$, a factor 100 lower than the first generation of Micromegas detectors. This reduction is based on active and passive shielding techniques, the selection of radiopure materials, offline discrimination techniques and the high granularity of the readout. We describe in detail the background model of the detector, based on its operation at CAST site and at the Canfranc Underground Laboratory (LSC), as well as on Geant4 simulations. The best levels currently achieved at LSC are low than 10$^{-7}$ keV$^{-1}$ ...

  2. Conceptual design of the International Axion Observatory (IAXO)

    International Nuclear Information System (INIS)

    The International Axion Observatory (IAXO) will be a forth generation axion helioscope. As its primary physics goal, IAXO will look for axions or axion-like particles (ALPs) originating in the Sun via the Primakoff conversion of the solar plasma photons. In terms of signal-to-noise ratio, IAXO will be about 4–5 orders of magnitude more sensitive than CAST, currently the most powerful axion helioscope, reaching sensitivity to axion-photon couplings down to a few × 10−12 GeV−1 and thus probing a large fraction of the currently unexplored axion and ALP parameter space. IAXO will also be sensitive to solar axions produced by mechanisms mediated by the axion-electron coupling gae with sensitivity — for the first time — to values of gae not previously excluded by astrophysics. With several other possible physics cases, IAXO has the potential to serve as a multi-purpose facility for generic axion and ALP research in the next decade. In this paper we present the conceptual design of IAXO, which follows the layout of an enhanced axion helioscope, based on a purpose-built 20 m-long 8-coils toroidal superconducting magnet. All the eight 60cm-diameter magnet bores are equipped with focusing x-ray optics, able to focus the signal photons into ∼ 0.2 cm2 spots that are imaged by ultra-low-background Micromegas x-ray detectors. The magnet is built into a structure with elevation and azimuth drives that will allow for solar tracking for ∼ 12 h each day

  3. Surveying the Inner Solar System with an Infrared Space Telescope

    CERN Document Server

    Buie, Marc W; Linfield, Roger P

    2016-01-01

    We present an analysis of surveying the inner Solar System for objects that may pose some threat to the Earth. Most of the analysis is based on understanding the capability provided by Sentinel, a concept for an infrared space-based telescope placed in a heliocentric orbit near the distance of Venus. From this analysis, we show 1) the size range being targeted can affect the survey design, 2) the orbit distribution of the target sample can affect the survey design, 3) minimum observational arc length during the survey is an important metric of survey performance, and 4) surveys must consider objects as small as D=15-30 m to meet the goal of identifying objects that have the potential to cause damage on Earth in the next 100 years. Sentinel will be able to find 50% of all impactors larger than 40 meters in a 6.5 year survey. The Sentinel mission concept is shown to be as effective as any survey in finding objects bigger than D=140 m but is more effective when applied to finding smaller objects on Earth-impacti...

  4. Axions and Their Relatives

    CERN Document Server

    CERN. Geneva

    2005-01-01

    A summary of the status of axions and axion-like particles will be given. Special attention is devoted to the recent results of the PVLAS collaboration, which are in conflict with CAST data and with astrophysical constraints. Solutions to this puzzle and the implications for new physics are dicussed. The subject of axion-like particles as dark matter will be included in the lecture. Finally some new results on new forces mediated by light scalars are debated.

  5. Inflationary Axion Cosmology

    Science.gov (United States)

    Wilczek, Frank; Turner, Michael S.

    1990-09-01

    If Peccei-Quinn (PQ) symmetry is broken after inflation, the initial axion angle is a random variable on cosmological scales; based on this fact, estimates of the relic-axion mass density give too large a value if the axion mass is less than about 10-6 eV. This bound can be evaded if the Universe underwent inflation after PQ symmetry breaking and if the observable Universe happens to be a region where the initial axion angle was atypically small, .1 . (ma/10-6eV)0.59. We show consideration of fluctuations induced during inflation severely constrains the latter alternative.

  6. Experimental Axion Review

    CERN Document Server

    CERN. Geneva

    2016-01-01

    Axions are a natural consequence of the Peccei-Quinn mechanism, the most compelling solution to the strong-CP problem. Similar axion-like particles (ALPs) also appear in a number of possible extensions of the Standard Model, notably in string theories. Both axions and ALPs are very well motivated candidates for the Dark Matter, and in addition would be copiously produced at the stellar cores. Some anomalous astrophysical observations could be hinting the existence of these particles. They are object of increasing interest by experimentalists. I will briefly review the motivation to search for axions and ALPs, as well as the current status and future prospects of the experimental landscape.

  7. Slipping reconnection in a solar flare observed in high resolution with the GREGOR solar telescope

    CERN Document Server

    Sobotka, M; Denker, C; Balthasar, H; Jurčák, J; Liu, W; Berkefeld, T; Vera, M Collados; Feller, A; Hofmann, A; Kneer, F; Kuckein, C; Lagg, A; Louis, R E; von der Lühe, O; Nicklas, H; Schlichenmaier, R; Schmidt, D; Schmidt, W; Sigwarth, M; Solanki, S K; Soltau, D; Staude, J; Strassmeier, K G; Volkmer, R; Waldmann, T

    2016-01-01

    A small flare ribbon above a sunspot umbra in active region 12205 was observed on November 7, 2014, at 12:00 UT in the blue imaging channel of the 1.5 m GREGOR telescope, using a 1 A Ca II H interference filter. Context observations from the Atmospheric Imaging Assembly (AIA) onboard the Solar Dynamics Observatory (SDO), the Solar Optical Telescope (SOT) onboard Hinode, and the Interface Region Imaging Spectrograph (IRIS) show that this ribbon is part of a larger one that extends through the neighboring positive polarities and also participates in several other flares within the active region. We reconstructed a time series of 140 seconds of Ca II H images by means of the multiframe blind deconvolution method, which resulted in spatial and temporal resolutions of 0.1 arcsec and 1 s. Light curves and horizontal velocities of small-scale bright knots in the observed flare ribbon were measured. Some knots are stationary, but three move along the ribbon with speeds of 7-11 km/s. Two of them move in the opposite d...

  8. Future axion searches with the International Axion Observatory (IAXO)

    DEFF Research Database (Denmark)

    Irastorza, I G; Avignone, F T; Cantatore, G;

    2013-01-01

    The International Axion Observatory (IAXO) is a new generation axion helioscope aiming at a sensitivity to the axion-photon coupling of gaγ (≳) few × 10−12 GeV−1, i.e. 1–1.5 orders of magnitude beyond the one achieved by CAST, currently the most sensitive axion helioscope. The main elements of IAXO...

  9. Multi Element Telescope for Imaging and Spectroscopy (METIS) coronagraph for the Solar Orbiter mission

    Czech Academy of Sciences Publication Activity Database

    Antonucci, E.; Fineschi, S.; Naletto, G.; Romoli, M.; Spadaro, D.; Nicolini, G.; Nicolosi, P.; Abbo, L.; Andretta, V.; Bemporad, A.; Auchere, F.; Berlicki, Arkadiusz; Bruno, R.; Capobianco, G.; Ciaravella, A.; Crescenzio, G.; Da Deppo, V.; D'Amicis, R.; Focardi, M.; Frassetto, F.; Heinzel, Petr; Lamy, P.; Landini, F.; Massone, G.; Malvezzi, M.A.; Dan Moses, J.; Pancrazzi, M.; Pelizzo, M.-G.; Poletto, L.; Schühle, U.H.; Solanki, S.K.; Telloni, D.; Teriaca, L.; Uslenghi, M.

    Bellingham : International Society for Optical Engineering, 2012, 844309-1-844309-12. ISBN 9780819491442. - (Proceedings of SPIE. 8443). [Space Telescope s and Instrumentation 2012: Ultraviolet to Gamma Ray. Amsterdam (NL), 01.07.2012-06.07.2012] Institutional support: RVO:67985815 Keywords : METIS * solar corona * solar wind Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  10. Detecting ultralight axion dark matter wind with laser interferometers

    CERN Document Server

    Aoki, Arata

    2016-01-01

    The ultralight axion with mass around $10^{-23}$ eV is known as a candidate of dark matter. A peculiar feature of the ultralight axion is oscillating pressure in time, which produces oscillation of gravitational potentials. Since the solar system moves through the dark matter halo at the velocity of about $v \\sim 300 \\, \\text{km} / \\text{s} = 10^{-3}$, there exists axion wind, which looks like scalar gravitational waves for us. Hence, there is a chance to detect ultralight axion dark matter with a wide mass range by using laser interferometer detectors. We calculate the detector signal induced by the oscillating pressure of the ultralight axion field, which would be detected by future laser interferometer experiments. We also argue that the detector signal can be enhanced due to the resonance in modified gravity theory explaining the dark energy.

  11. Axions as Dark Matter Particles

    OpenAIRE

    Duffy, Leanne D.; Bibber, Karl van

    2009-01-01

    We review the current status of axions as dark matter. Motivation, models, constraints and experimental searches are outlined. The axion remains an excellent candidate for the dark matter and future experiments, particularly the Axion Dark Matter eXperiment (ADMX), will cover a large fraction of the axion parameter space.

  12. The 1.5 meter solar telescope GREGOR

    Czech Academy of Sciences Publication Activity Database

    Schmidt, W.; von der Lühe, O.; Volkmer, R.; Denker, C.; Solanki, S.K.; Balthasar, H.; Bello González, N.; Berkefeld, T.; Collados, M.; Fischer, A.; Halbgewachs, C.; Heidecke, F.; Hofmann, A.; Kneer, F.; Lagg, A.; Nicklas, H.; Popow, E.; Puschmann, K.G.; Schmidt, D.; Sigwarth, M.; Sobotka, Michal; Soltau, D.; Staude, J.; Strassmeier, K.G.; Waldmann, T.A.

    2012-01-01

    Roč. 333, č. 9 (2012), s. 796-809. ISSN 0004-6337 Institutional support: RVO:67985815 Keywords : high angular resolution * magnetic fields * telescopes Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 1.399, year: 2012

  13. The Prototype of the Small Synoptic Second Solar Spectrum Telescope (S5T)

    OpenAIRE

    Snik, Frans; Melich, Radek; Keller, Christoph

    2009-01-01

    We present the design and the prototype of the Small Synoptic Second Solar Spectrum Telescope (S5T), which can autonomously measure scattering polarization signals on a daily basis with large sensitivity and accuracy. Its data will be used to investigate the nature of weak, turbulent magnetic fields through the Hanle effect in many lines. Also the relation between those fields and the global solar dynamo can be revealed by spanning the observations over a significant fraction of a solar cycle...

  14. Axion Dark Matter Searches

    CERN Document Server

    Stern, I

    2014-01-01

    Nearly all astrophysical and cosmological data point convincingly to a large component of cold dark matter in the Universe. The axion particle, first theorized as a solution to the strong charge-parity problem of quantum chromodynamics, has been established as a prominent CDM candidate. Cosmic observation and particle physics experiments have bracketed the unknown mass of the axion between approximately a $\\mu$eV and a meV. The Axion Dark Matter eXperiement (ADMX) has successfully completed searches between 1.9 and 3.7 $\\mu$eV down to the KSVZ photon-coupling limit. ADMX and the Axion Dark Matter eXperiement High-Frequency (ADMX-HF) will search for axions at weaker coupling and/or higher frequencies within the next few years. Status of the experiments, current research and development, and projected mass-coupling exclusion limits are presented.

  15. Future cosmological sensitivity for hot dark matter axions

    CERN Document Server

    Archidiacono, Maria; Hamann, Jan; Hannestad, Steen; Raffelt, Georg; Wong, Yvonne Y Y

    2015-01-01

    We study the potential of a future, large-volume photometric survey to constrain the axion mass $m_a$ in the hot dark matter limit. Future surveys such as Euclid will have significantly more constraining power than current observations for hot dark matter. Nonetheless, the lowest accessible axion masses are limited by the fact that axions lighter than $\\sim 0.15$ eV decouple before the QCD epoch, assumed here to occur at a temperature $T_{\\rm QCD} \\sim 170$ MeV; this leaves an axion population of such low density that its late-time cosmological impact is negligible. For larger axion masses, $m_a \\gtrsim 0.15$ eV, where axions remain in equilibrium until after the QCD phase transition, we find that a Euclid-like survey combined with Planck CMB data can detect $m_a$ at very high significance. Our conclusions are robust against assumptions about prior knowledge of the neutrino mass. Given that the proposed IAXO solar axion search is sensitive to $m_a\\lesssim 0.2$ eV, the axion mass range probed by cosmology is n...

  16. The Focal Plane Package for the Solar Optical Telescope on Solar-B

    Science.gov (United States)

    Tarbell, T. D.

    2005-05-01

    Solar-B is a space science mission of the Japanese Aerospace Exploration Agency (JAXA) and a NASA Solar Terrestrial Probes mission. It includes the 50-cm aperture Solar Optical Telescope (SOT), with its Focal Plane Package (FPP) designed for high resolution photospheric and chromospheric imaging and spectro-polarimetry. There are also two coronal instruments, the X-Ray Telescope and Extreme-ultraviolet Imaging Spectrometer. Solar-B will be launched into a Sun-synchronous polar orbit in August, 2006. The SOT is provided by JAXA and is being built by the National Astronomical Observatory of Japan (NAOJ) and Mitsubishi Electric Co. A team of Lockheed Martin, High Altitude Observatory (HAO), and NAOJ scientists and engineers have built the FPP instrument. This paper gives an overview of the science goals of the FPP as well as the instrument performance characteristics. The primary goal is to understand the coupling between the fine magnetic structures in the photosphere and dynamic processes and heating in the chromosphere and corona. The FPP consists of a narrow-band tunable birefringent filter imager, broad-band interference filter imager, and spectro-polarimeter (SP), essentially a space version of the HAO Advanced Stokes Polarimeter. The image is stabilized by a correlation tracker and active tilt mirror. The SP makes vector magnetic measurements from Stokes spectra of the Fe I lines 630.1 and 630.2 nm, with 0.16 arcsec pixels and field of view up to 164 x 328 arcsec. The broad-band system takes diffraction-limited images (0.05 arcsec pixels) in the Ca II H line, CN and G bandheads, and continuum bands. The narrow-band system makes filtergrams, magnetograms, Dopplergrams, and Stokes images in several photospheric lines, Mg b, Na D, and H-alpha, similar to the SOUP filter at La Palma. It has 0.08 arcsec pixels and field-of-view same as that of the SP. SOT and FPP have been calibrated in great detail and have observed the sun in two end-to-end tests at NAOJ. Sample

  17. Progress of site survey for large solar telescopes in western China

    Science.gov (United States)

    Liu, Yu

    2015-08-01

    Excellent sites are necessary for developing and installing ground-based large telescopes. For solar telescopes, it had been unclear whether there exist good candidate sites in the west areas in China, including the Tibetan Plateau and the Pamirs Plateau, before the project of solar site survey for our next-generation large solar telescopes, i.e., the Chinese Giant Solar Telescope (CGST) and the large coronagraph, has been lauched since 2011. Based on the close collaboration among Chinese solar society and the scientists from NSO, HAO and other institutes, we have successfully developed the standard insturments for solar site survey and applied them to more than 50 different sites distributed in Xinjiang, Tibet, Qinghai, Sichuan, Yunnan and Ningxia provinces. We have built two long-term monitoring sites in Tibet and the large Shangri-La to take systematic site data. Clear evidence, including the key parameters of seeing factor, sky brightness and water vapor content, has indicated that a few potential sites in the large Tibetan areas should obtain the excellent astronomical conditions for our purpose to develop CGST and large coronagraph. We'll introduce and discuss the fresh site survey results in our report.

  18. Windows on the axion

    International Nuclear Information System (INIS)

    Peccei-Quinn symmetry with attendant axion is a most compelling, and perhaps the most minimal, extension of the standard model, as it provides a very elegant solution to the nagging strong CP-problem associated with the Θ vacuum structure of QCD. However, particle physics gives little guidance as to the axion mass; a priori, the plausible values span the range: 10/sup /minus/12/ eV /approx lt/ m/sub a/ /approx lt/ 106 eV, some 18 orders-of-magnitude. Axions have a host of interesting astrophysical and cosmological effects, including, modifying the evolution of stars of all types (our sun, red giants, white dwarfs, and neutron stars), contributing significantly to the mass density of the Universe today, and producing detectable line radiation through the decays of relic axions. Consideration of these effects has probed 14 orders-of-magnitude in axion mass, and has left open only two windows for further exploration: 10/sup /minus/6/ eV /approx lt/ m/sub a/ /approx lt/ 10/sup /minus/3/ eV and 1 eV /approx lt/ m/sub a/ /approx lt/ 5 eV (hadronic axions only). Both these windows are accessible to experiment, and a variety of very interesting experiments, all of which involve ''heavenly axions,'' are being planned or are underway. 58 refs., 6 figs., 1 tab

  19. (Mainly) axion dark matter

    CERN Document Server

    Baer, Howard

    2015-01-01

    The strong CP problem of QCD is at heart a problem of naturalness: why is the F\\tilde{F} term highly suppressed in the QCD Lagrangian when it seems necessary to explain why there are three and not four light pions? The most elegant solution posits a spontaneously broken Peccei-Quinn (PQ) symmetry which requires the existence of the axion field a. The axion field settles to the minimum of its potential thus removing the offensive term but giving rise to the physical axion whose coherent oscillations can make up the cold dark matter. Only now are experiments such as ADMX beginning to explore QCD axion parameter space. Since a bonafide scalar particle-- the Higgs boson-- has been discovered, one might expect its mass to reside at the axion scale f_a~ 10^{11} GeV. The Higgs mass is elegantly stabilized by supersymmetry: in this case the axion is accompanied by its axino and saxion superpartners. Requiring naturalness also in the electroweak sector implies higgsino-like WIMPs so then we expect mixed axion-WIMP dar...

  20. Windows on the axion

    Energy Technology Data Exchange (ETDEWEB)

    Turner, M.S.

    1989-04-01

    Peccei-Quinn symmetry with attendant axion is a most compelling, and perhaps the most minimal, extension of the standard model, as it provides a very elegant solution to the nagging strong CP-problem associated with the THETA vacuum structure of QCD. However, particle physics gives little guidance as to the axion mass; a priori, the plausible values span the range: 10/sup /minus/12/ eV /approx lt/ m/sub a/ /approx lt/ 10/sup 6/ eV, some 18 orders-of-magnitude. Axions have a host of interesting astrophysical and cosmological effects, including, modifying the evolution of stars of all types (our sun, red giants, white dwarfs, and neutron stars), contributing significantly to the mass density of the Universe today, and producing detectable line radiation through the decays of relic axions. Consideration of these effects has probed 14 orders-of-magnitude in axion mass, and has left open only two windows for further exploration: 10/sup /minus/6/ eV /approx lt/ m/sub a/ /approx lt/ 10/sup /minus/3/ eV and 1 eV /approx lt/ m/sub a/ /approx lt/ 5 eV (hadronic axions only). Both these windows are accessible to experiment, and a variety of very interesting experiments, all of which involve ''heavenly axions,'' are being planned or are underway. 58 refs., 6 figs., 1 tab.

  1. Solar synoptic telescope. Characteristics, possibilities, and limits of design

    Czech Academy of Sciences Publication Activity Database

    Klvaňa, Miroslav; Sobotka, Michal; Švanda, Michal

    2011-01-01

    Roč. 41, č. 2 (2011), s. 92-98. ISSN 1335-1842 R&D Projects: GA AV ČR IAA300030808 Institutional research plan: CEZ:AV0Z10030501 Keywords : Sun * telescope s Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 0.152, year: 2011

  2. Search for energetic cosmic axions utilizing terrestrial/celestial magnetic fields

    CERN Document Server

    Zioutas, Konstantin; Paschos, E A

    1998-01-01

    Orbiting $\\gamma$-detectors combined with the magnetic field of the Earth or the Sun can work parasitically as cosmic axion telescopes. The relatively short field lengths allow the axion-to-photon conversion to be coherent for $m_{axion} \\sim 10^{-4}$ eV, if the axion kinetic energy is above $\\sim 500$ keV (Earth's field), or, $\\sim 50$ MeV (Sun's field), allowing thus to search for axions from $e^+e^-$ annihilations, from supernova explosions, etc. With a detector angular resolution of $\\sim 1^o$, a more efficient sky survey for energetic cosmic axions passing {\\it through the Sun} can be performed. Axions or other axion-like particles might be created by the interaction of the cosmic radiation with the Sun, similarly to the axion searches in accelerator beam dump experiments; the enormous cosmic energy combined with the built-in coherent Primakoff effect might provide a sensitive detection scheme, being out of reach with accelerators. The axion signal will be an excess in $\\gamma$-rays coming either from a ...

  3. Axion hot dark matter bounds after Planck

    Energy Technology Data Exchange (ETDEWEB)

    Archidiacono, Maria; Hannestad, Steen [Department of Physics and Astronomy, University of Aarhus DK-8000 Aarhus C (Denmark); Mirizzi, Alessandro [II. Institut für Theoretische Physik, Universität Hamburg Luruper Chaussee 149, D-22761 Hamburg (Germany); Raffelt, Georg [Max-Planck-Institut für Physik (Werner-Heisenberg-Institut) Föhringer Ring 6, D-80805 München (Germany); Wong, Yvonne Y.Y., E-mail: archi@phys.au.dk, E-mail: sth@phys.au.dk, E-mail: alessandro.mirizzi@desy.de, E-mail: raffelt@mpp.mpg.de, E-mail: yvonne.y.wong@unsw.edu.au [School of Physics, The University of New South Wales Sydney NSW 2052 (Australia)

    2013-10-01

    We use cosmological observations in the post-Planck era to derive limits on thermally produced cosmological axions. In the early universe such axions contribute to the radiation density and later to the hot dark matter fraction. We find an upper limit m{sub a} < 0.67 eV at 95% C.L. after marginalising over the unknown neutrino masses, using CMB temperature and polarisation data from Planck and WMAP respectively, the halo matter power spectrum extracted from SDSS-DR7, and the local Hubble expansion rate H{sub 0} released by the Carnegie Hubble Program based on a recalibration of the Hubble Space Telescope Key Project sample. Leaving out the local H{sub 0} measurement relaxes the limit somewhat to 0.86 eV, while Planck+WMAP alone constrain the axion mass to 1.01 eV, the first time an upper limit on m{sub a} has been obtained from CMB data alone. Our axion limit is therefore not very sensitive to the tension between the Planck-inferred H{sub 0} and the locally measured value. This is in contrast with the upper limit on the neutrino mass sum, which we find here to range from Σ m{sub ν} < 0.27 eV at 95% C.L. combining all of the aforementioned observations, to 0.84 eV from CMB data alone.

  4. Axion hot dark matter bounds after Planck

    CERN Document Server

    Archidiacono, Maria; Mirizzi, Alessandro; Raffelt, Georg; Wong, Yvonne Y Y

    2013-01-01

    We use cosmological observations in the post-Planck era to derive limits on thermally produced cosmological axions. In the early universe such axions contribute to the radiation density and later to the hot dark matter fraction. We find an upper limit m_a < 0.67 eV at 95% C.L. after marginalising over the unknown neutrino masses, using CMB temperature and polarisation data from Planck and WMAP respectively, the halo matter power spectrum extracted from SDSS-DR7, and the local Hubble expansion rate H_0 released by the Carnegie Hubble Program based on a recalibration of the Hubble Space Telescope Key Project sample. Leaving out the local H_0 measurement relaxes the limit somewhat to 0.86 eV, while Planck+WMAP alone constrain the axion mass to 1.01 eV, the first time an upper limit on m_a has been obtained from CMB data alone. Our axion limit is therefore not very sensitive to the tension between the Planck-inferred H_0 and the locally measured value. This is in contrast with the upper limit on the neutrino m...

  5. Towards a realistic axion star

    CERN Document Server

    Barranco, J

    2008-01-01

    In this work we estimate the radius and the mass of a self-gravitating system made of axions. The quantum axion field satisfies the Klein-Gordon equation in a curved space-time and the metric components of this space-time are solutions to the Einstein equations with a source term given by the vacuum expectation value of the energy-momentum operator constructed from the axion field. As a first step towards an axion star we consider the up to the sixth term in the axion potential expansion. We found that axion stars would have masses of the order of asteroids and radius of the order of few centimeters.

  6. Axions: a review

    International Nuclear Information System (INIS)

    The axion particle is the experimental consequence of a particular way to restore P conservation into the QCD theory. The standard axion phenomenology proceeds on a scale given by the electroweak symmetry breaking. Such an axion is ruled out experimentally. Recently, observation of monochromatic peaks in e± production in heavy-ion collisions at GSI Darmstadt has motivated some re-examination of the situation. There appears to be no way to save the notion of an axion at the electroweak scale. Furthermore, experiments with electron beam-dumps have proven, together with g-2 measurements that the GSI effect cannot be explained in terms of a fundamental particle coupled to the e+e- channel

  7. Collapse of Axion Stars

    CERN Document Server

    Eby, Joshua; Suranyi, Peter; Wijewardhana, L C R

    2016-01-01

    Axion stars, gravitationally bound states of low-energy axion particles, have a maximum mass allowed by gravitational stability. Weakly bound states obtaining this maximum mass have sufficiently large radii such that they are dilute, and as a result, they are well described by a leading-order expansion of the axion potential. Heavier states are susceptible to gravitational collapse. Inclusion of higher-order interactions, present in the full potential, can give qualitatively different results in the analysis of collapsing heavy states, as compared to the leading-order expansion. In this work, we find that collapsing axion stars are stabilized by repulsive interactions present in the full potential, providing evidence that such objects do not form black holes. These dense configurations, which are the endpoints of collapse, have extremely high binding energy, and as a result, decay through number changing $3\\,a\\rightarrow a$ interactions with an extremely short lifetime.

  8. Extracting information from the data flood of new solar telescopes. Brainstorming

    CERN Document Server

    Ramos, A Asensio

    2012-01-01

    Extracting magnetic and thermodynamic information from spectropolarimetric observations is a difficult and time consuming task. The amount of science-ready data that will be generated by the new family of large solar telescopes is so large that we will be forced to modify the present approach to inference. In this contribution, I propose several possible ways that might be useful for extracting the thermodynamic and magnetic properties of solar plasmas from such observations quickly.

  9. Axions and Dark Matter

    OpenAIRE

    Yang, Qiaoli

    2015-01-01

    Dark matter particles constitute $23\\%$ of the total energy density of our universe and their exact properties are still unclear besides that they must be very cold and weakly interacting with the standard model particles. Many beyond standard model theories provide proper candidates to serve as the dark matter. The axions were introduced to solve the strong CP problem and later turned out to be a very attractive dark matter candidate. In this paper, we briefly review the physics of axions an...

  10. The hunt for axions

    International Nuclear Information System (INIS)

    Many theoretically well-motivated extensions of the Standard Model of particle physics predict the existence of the axion and further ultralight axion-like particles. They may constitute the mysterious dark matter in the universe and solve some puzzles in stellar and high-energy astrophysics. There are new, relatively small experiments around the globe, which started to hunt for these elusive particles and complement the accelerator based search for physics beyond the Standard Model.

  11. Hierarchical axion inflation

    International Nuclear Information System (INIS)

    We propose a new field theory mechanism for generating an effective trans-Planckian decay constant from sub-Planckian ones. Using the minimal two axions and a hierarchy between two axion decay constants is sufficient for realizing inflation through non-perturbative effects only and with minimal tuning. The inflationary motion is kept entirely within a sub-Planckian domain. We outline possible strategies of embedding the model in a string theory setup.

  12. The new 1.5 solar telescope GREGOR: progress report and results of performance tests

    Czech Academy of Sciences Publication Activity Database

    Volkmer, R.; von der Lühe, O.; Kneer, F.; Staude, J.; Berkefeld, T.; Caligari, P.; Halbgewachs, C.; Schmidt, W.; Soltau, D.; Niclas, H.; Wittmann, A.; Balthasar, H.; Hofmann, A.; Strassmeier, K.G.; Sobotka, Michal; Klvaňa, Miroslav; Colados, M.

    Bellingham : SPIE - International Society for Optical Engineering, 2005, s. 75-83. ISBN 0-8194-5971-2. - (Proceedings of SPIE. 5901). [Optics and Photonics 2005. San Diego (US), 31.07.2005-04.08.2005] Keywords : solar telescope Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  13. Detecting Life-bearing Extra-solar Planets with Space Telescopes

    CERN Document Server

    Beckwith, Steven V W

    2007-01-01

    One of the promising methods to search for life on extra-solar planets (exoplanets) is to detect life's signatures in their atmospheres. Spectra of exoplanet atmospheres at the modest resolution needed to search for oxygen, carbon dioxide, water, and methane will demand large collecting areas and large diameters to capture and isolate the light from planets in the habitable zones around the stars. For telescopes using coronagraphs to isolate the light from the planet, each doubling of telescope diameter will increase the available sample of stars by an order of magnitude, indicating a high scientific return if the technical difficulties of constructing very large space telescopes can be overcome. For telescopes detecting atmospheric signatures of transiting planets, the sample size increases only linearly with diameter, and the available samples are probably too small to guarantee detection of life-bearing planets. Using samples of nearby stars suitable for exoplanet searches, this paper shows that the demand...

  14. On the Use of Cherenkov Telescopes for Outer Solar System Body Occultations

    CERN Document Server

    Lacki, Brian C

    2014-01-01

    Imaging Atmosphere Cherenkov Telescopes (IACT) are arrays of very large optical telescopes that are well-suited for rapid photometry of bright sources. I investigate their potential in observing stellar occultations by small objects in the outer Solar System, Transjovian Objects (TJOs). These occultations cast diffraction patterns on the Earth. Current IACT arrays are capable of detecting objects smaller than 100 meters in radius in the Kuiper Belt and 1 km radius out to 5000 AU. The future Cherenkov Telescope Array (CTA) will have even greater capabilities. Because the arrays include several telescopes, they can potentially measure the speeds of TJOs without degeneracies, and the sizes of the TJOs and background stars. I estimate the achievable precision using a Fisher matrix analysis. With CTA, the precisions of these parameter estimations will be as good as a few percent. I consider how often IACTs can observe occultations by members of different TJO populations, including Centaurs, Kuiper Belt Objects (KB...

  15. Solar observations with a low frequency radio telescope

    Science.gov (United States)

    Myserlis, I.; Seiradakis, J.; Dogramatzidis, M.

    2012-01-01

    We have set up a low frequency radio monitoring station for solar bursts at the Observatory of the Aristotle University in Thessaloniki. The station consists of a dual dipole phased array, a radio receiver and a dedicated computer with the necessary software installed. The constructed radio receiver is based on NASA's Radio Jove project. It operates continuously, since July 2010, at 20.1 MHz (close to the long-wavelength ionospheric cut-off of the radio window) with a narrow bandwidth (~5 kHz). The system is properly calibrated, so that the recorded data are expressed in antenna temperature. Despite the high interference level of an urban region like Thessaloniki (strong broadcasting shortwave radio stations, periodic experimental signals, CBs, etc), we have detected several low frequency solar radio bursts and correlated them with solar flares, X-ray events and other low frequency solar observations. The received signal is monitored in ordinary ASCII format and as audio signal, in order to investigate and exclude man-made radio interference. In order to exclude narrow band interference and calculate the spectral indices of the observed events, a second monitoring station, working at 36 MHz, is under construction at the village of Nikiforos near the town of Drama, about 130 km away of Thessaloniki. Finally, we plan to construct a third monitoring station at 58 MHz, in Thessaloniki. This frequency was revealed to be relatively free of interference, after a thorough investigation of the region.

  16. Anomaly mediation deformed by axion

    International Nuclear Information System (INIS)

    We show that in supersymmetric axion models the axion supermultiplet obtains a sizable F-term due to a non-supersymmetric dynamics and it generally gives the gaugino masses comparable to the anomaly mediation contribution. Thus the gaugino mass relation predicted by the anomaly mediation effect can be significantly modified in the presence of axion to solve the strong CP problem

  17. The x-ray/EUV telescope for the Solar-C mission: science and development activities

    Science.gov (United States)

    Sakao, Taro; Narukage, Noriyuki; Imada, Shinsuke; Suematsu, Yoshinori; Shimojo, Masumi; Tsuneta, Saku; DeLuca, Edward E.; Watanabe, Kyoko; Ishikawa, Shin-nosuke

    2012-09-01

    We report science and development activities of the X-ray/EUV telescope for the Japanese Solar-C mission whose projected launch around 2019. The telescope consists of a package of (a) a normal-incidence (NI) EUV telescope and (b) a grazing-incidence (GI) soft X-ray telescope. The NI telescope chiefly provides images of low corona (whose temperature 1 MK or even lower) with ultra-high angular resolution (0.2-0.3"/pixel) in 3 wavelength bands (304, 171, and 94 angstroms). On the other hand, the GI telescope provides images of the corona with a wide temperature coverage (1 MK to beyond 10 MK) with the highest-ever angular resolution (~0.5"/pixel) as a soft X-ray coronal imager. The set of NI and GI telescopes should provide crucial information for establishing magnetic and gas-dynamic connection between the corona and the lower atmosphere of the Sun which is essential for understanding heating of, and plasma activities in, the corona. Moreover, we attempt to implement photon-counting capability for the GI telescope with which imaging-spectroscopy of the X-ray corona will be performed for the first time, in the energy range from ~0.5 keV up to 10 keV. The imaging-spectroscopic observations will provide totally-new information on mechanism(s) for the generation of hot coronal plasmas (heated beyond a few MK), those for magnetic reconnection, and even generation of supra-thermal electrons associated with flares. An overview of instrument outline and science for the X-ray photoncounting telescope are presented, together with ongoing development activities in Japan towards soft X-ray photoncounting observations, focusing on high-speed X-ray CMOS detector and sub-arcsecond-resolution GI mirror.

  18. Quantitative evaluation on internal seeing induced by heat-stop of solar telescope.

    Science.gov (United States)

    Liu, Yangyi; Gu, Naiting; Rao, Changhui

    2015-07-27

    heat-stop is one of the essential thermal control devices of solar telescope. The internal seeing induced by its temperature rise will degrade the imaging quality significantly. For quantitative evaluation on internal seeing, an integrated analysis method based on computational fluid dynamics and geometric optics is proposed in this paper. Firstly, the temperature field of the heat-affected zone induced by heat-stop temperature rise is obtained by the method of computational fluid dynamics calculation. Secondly, the temperature field is transformed to refractive index field by corresponding equations. Thirdly, the wavefront aberration induced by internal seeing is calculated by geometric optics based on optical integration in the refractive index field. This integrated method is applied in the heat-stop of the Chinese Large Solar Telescope to quantitatively evaluate its internal seeing. The analytical results show that the maximum acceptable temperature rise of heat-stop is up to 5 Kelvins above the ambient air at any telescope pointing directions under the condition that the root-mean-square of wavefront aberration induced by internal seeing is less than 25nm. Furthermore, it is found that the magnitude of wavefront aberration gradually increases with the increase of heat-stop temperature rise for a certain telescope pointing direction. Meanwhile, with the variation of telescope pointing varying from the horizontal to the vertical direction, the magnitude of wavefront aberration decreases at first and then increases for the same heat-stop temperature rise. PMID:26367657

  19. Future axion searches with the International Axion Observatory (IAXO)

    CERN Document Server

    Irastorza, I G; Cantatore, G; Carmona, J M; Caspi, S; Cetin, S A; Christensen, F E; Dael, A; Dafni, T; Davenport, M; Derbin, A V; Desch, K; Diago, A; Döbrich, B; Dudarev, A; Eleftheriadis, C; Fanourakis, G; Ferrer-Ribas, E; Galán, J; García, J A; Garza, J.G; Geralis, T; Gimeno, B; Giomataris, I; Gninenko, S; Gómez, H; Guendelman, E; Hailey, C J; Hiramatsu, T; Hoffmann, D H H; Horns, D; Iguaz, F J; Isern, J; Jakobsen, A C; Jaeckel, J; Jakovčić, K; Kaminski, J; Kawasaki, M; Krčmar, M; Krieger, C; Lakić, B; Lindner, A; Liolios, A; Luzón, G; Ortega, I; Papaevangelou, T; Pivovaroff, M J; Raffelt, G; Redondo, J; Ringwald, A; Russenschuck, S; Ruz, J; Saikawa, K; Savvidis, I; Sekiguchi, T; Shilon, I; Sikivie, P; Silva, H; Kate, H ten; Tomas, A; Troitsky, S; Vafeiadis, T; Bibber, K van; Vedrine, P; Villar, J A; Vogel, J K; Walckiers, L; Wester, W; Yildiz, S C; Zioutas, K

    2013-01-01

    The International Axion Observatory (IAXO) is a new generation axion helioscope aiming at a sensitivity to the axion-photon coupling of gaγ few × 10−12 GeV−1, i.e. 1–1.5 orders of magnitude beyond the one achieved by CAST, currently the most sensitive axion helioscope. The main elements of IAXO are an increased magnetic field volume together with extensive use of x-ray focusing optics and low background detectors, innovations already successfully tested in CAST. Additional physics cases of IAXO could include the detection of electron-coupled axions invoked to explain the white dwarf cooling, relic axions, and a large variety of more generic axion-like particles (ALPs) and other novel excitations at the low-energy frontier of elementary particle physics.

  20. Future axion searches with the International Axion Observatory (IAXO)

    International Nuclear Information System (INIS)

    The International Axion Observatory (IAXO) is a new generation axion helioscope aiming at a sensitivity to the axion-photon coupling of gaγ ∼> few × 10−12 GeV−1, i.e. 1–1.5 orders of magnitude beyond the one achieved by CAST, currently the most sensitive axion helioscope. The main elements of IAXO are an increased magnetic field volume together with extensive use of x-ray focusing optics and low background detectors, innovations already successfully tested in CAST. Additional physics cases of IAXO could include the detection of electron-coupled axions invoked to explain the white dwarf cooling, relic axions, and a large variety of more generic axion-like particles (ALPs) and other novel excitations at the low-energy frontier of elementary particle physics

  1. Thermal effects in the Solar Disk Sextant telescope

    Science.gov (United States)

    Spagnesi, Chiara; Vannoni, Maurizio; Molesini, Giuseppe; Righini, Alberto

    2004-02-01

    The Solar Disk Sextant (SDS) is an instrument conceived to monitor the diameter of the Sun and its oscillations. A key component of the SDS is the Beam Splitting Wedge (BSW), whose function is to provide calibration to the geometry of the focal plane. The thermal behavior of the BSW is critical, as it affects the overall performance of the instrument. Modeling the elements of the BSW and the basic thermal processes is shown to account for experimental evidences of defocusing observed in early measurements with a balloon borne prototype. Basic requirements for accurate thermal stabilization on board of the final instrument are derived.

  2. The International Axion Observatory IAXO. Letter of Intent to the CERN SPS committee

    CERN Document Server

    Irastorza, Igor G

    2013-01-01

    This Letter of Intent describes IAXO, the International Axion Observatory, a proposed 4th generation axion helioscope. As its primary physics goal, IAXO will look for axions or axion-like particles (ALPs) originating in the Sun via the Primakoff conversion of the solar plasma photons. In terms of signal to background ratio, IAXO will be about 4-5 orders of magnitude more sensitive than CAST, which means that this instrument will reach sensitivity to axion-photon couplings down to a few $\\times 10^{-12}$ GeV$^{-1}$. IAXO has the potential for the discovery of axions and other ALPs, since it will deeply enter into unexplored parameter space. At the very least it will firmly exclude a large region of this space of high cosmological and astrophysical relevance. In particular it will probe a large fraction of the high mass part (1 meV to 1 eV) of the QCD axion allowed window. Additional physics cases for IAXO include the possibility of detecting solar axions produced by mechanisms mediated by the axion-electron co...

  3. Dark Matter in Axion Landscape

    OpenAIRE

    Daido, Ryuji; Kobayashi, Takeshi; Takahashi, Fuminobu

    2016-01-01

    If there are a plethora of axions in nature, they may have a complicated potential and create an axion landscape. We study a possibility that one of the axions is so light that it is cosmologically stable, explaining the observed dark matter density. In particular we focus on a case in which two (or more) shift-symmetry breaking terms conspire to make the axion sufficiently light at the potential minimum. In this case the axion has a flat-bottomed potential. In contrast to the case in which a...

  4. Observation of the 2005 January 20 GLE event using Yangbajing solar neutron telescope and neutron monitor

    International Nuclear Information System (INIS)

    A solar cosmic rays Ground Level Enhancement (GLE) event associated with a X7.1/2b solar flare in 2005 January 20 was observed by the Yangbajing solar neutron telescope (SNT) and neutron monitor (NM), located at Yangbajing Tibet (90.53 degree E, 30.11 degree N, 4310m a.s.l) with the highest vertical geomagnetic cut-off rigidity of 14.1 GV in NM network. The statistical significance of the counting rate enhancement recorded by solar neutron telescope in >40 MeV channel was 3.7 σ in the time window of 07:00-07:05UT and 6.0σ in the time window of 07:00-07:20UT, respectively. The onset time of 06:51-06:52UT for this GLE event was clearly observed by the Yangbajing NM. Our Observation indicates that solar protons have been accelerated up to energies of >10 GeV during this solar event. (authors)

  5. Axion domain wall baryogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Daido, Ryuji; Kitajima, Naoya [Department of Physics, Tohoku University,Sendai 980-8578 (Japan); Takahashi, Fuminobu [Department of Physics, Tohoku University,Sendai 980-8578 (Japan); Kavli IPMU, TODIAS, University of Tokyo,Kashiwa 277-8583 (Japan)

    2015-07-28

    We propose a new scenario of baryogenesis, in which annihilation of axion domain walls generates a sizable baryon asymmetry. Successful baryogenesis is possible for a wide range of the axion mass and decay constant, m≃10{sup 8}–10{sup 13} GeV and f≃10{sup 13}–10{sup 16} GeV. Baryonic isocurvature perturbations are significantly suppressed in our model, in contrast to various spontaneous baryogenesis scenarios in the slow-roll regime. In particular, the axion domain wall baryogenesis is consistent with high-scale inflation which generates a large tensor-to-scalar ratio within the reach of future CMB B-mode experiments. We also discuss the gravitational waves produced by the domain wall annihilation and its implications for the future gravitational wave experiments.

  6. Dark Matter in Axion Landscape

    CERN Document Server

    Daido, Ryuji; Takahashi, Fuminobu

    2016-01-01

    If there are a plethora of axions in nature, they may have a complicated potential and create an axion landscape. We study a possibility that one of the axions is so light that it is cosmologically stable, explaining the observed dark matter density. In particular we focus on a case in which two (or more) shift-symmetry breaking terms conspire to make the axion sufficiently light at the potential minimum. In this case the axion has a flat-bottomed potential. In contrast to the case in which a single cosine term dominates the potential, the axion abundance as well as its isocurvature perturbations are significantly suppressed. This allows an axion with a rather large mass to serve as dark matter without fine-tuning of the initial misalignment, and further makes higher-scale inflation to be consistent with the scenario.

  7. Axionic Mirage Mediation

    International Nuclear Information System (INIS)

    In this talk, we propose a model of mirage mediation, in which Peccei-Quinn symmetry is incorporated. In this axionic mirage mediation, it is shown that the Peccei-Quinn symmetry breaking scale is dynamically determined around 1010 GeV to 1012 GeV due to the supersymmetry breaking effects. The problems in the original mirage mediation such as the μ-problem and the moduli problem can be solved simultaneouly. Furthermore, in our model the axino, which is the superpartner of the axion, is the lightest sparticle.

  8. Axionic Mirage Mediation

    CERN Document Server

    Nakamura, Shuntaro; Yamaguchi, Masahiro

    2008-01-01

    In this talk, we propose a model of mirage mediation, in which Peccei-Quinn symmetry is incorporated. In this \\textit{axionic mirage mediation}, it is shown that the Peccei-Quinn symmetry breaking scale is dynamically determined around $10^{10}$ GeV to $10^{12}$ GeV due to the supersymmetry breaking effects. The problems in the original mirage mediation such as the $\\mu$-problem and the moduli problem can be solved simultaneouly. Furthermore, in our model the axino, which is the superpartner of the axion, is the lightest sparticle.

  9. Tunneling in Axion Monodromy

    CERN Document Server

    Brown, Jon; Shiu, Gary; Soler, Pablo

    2016-01-01

    The Coleman formula for vacuum decay and bubble nucleation has been used to estimate the tunneling rate in models of axion monodromy in recent literature. However, several of Coleman's original assumptions do not hold for such models. Here we derive a new estimate with this in mind using a similar Euclidean procedure. We find that there are significant regions of parameter space for which the tunneling rate in axion monodromy is not well approximated by the Coleman formula. However, there is also a regime relevant to large field inflation in which both estimates parametrically agree. We also briefly comment on the applications of our results to the relaxion scenario.

  10. Prospects for solar and space weather research with polish part of the LOFAR telescope

    Science.gov (United States)

    Dąbrowski, Bartosz P.; Krankowski, Andrzej; Błaszkiewicz, Leszek; Rothkaehl, Hanna

    2016-06-01

    The LOw-Frequency ARray (LOFAR) is a new radio interferometer that consists of an array of stations. Each of them is a phase array of dipole antennas. LOFAR stations are distributed mostly in the Netherlands, but also throughout Europe. In the article we discuss the possibility of using this instrument for solar and space weather studies, as well as ionosphere investigations. We are expecting that in the near future the LOFAR telescope will bring some interesting observations and discoveries in these fields. It will also help to observe solar active events that have a direct influence on the near-Earth space weather.

  11. Prospects for solar and space weather research with polish part of the LOFAR telescope

    Directory of Open Access Journals (Sweden)

    Dąbrowski Bartosz P.

    2016-06-01

    Full Text Available The LOw-Frequency ARray (LOFAR is a new radio interferometer that consists of an array of stations. Each of them is a phase array of dipole antennas. LOFAR stations are distributed mostly in the Netherlands, but also throughout Europe. In the article we discuss the possibility of using this instrument for solar and space weather studies, as well as ionosphere investigations. We are expecting that in the near future the LOFAR telescope will bring some interesting observations and discoveries in these fields. It will also help to observe solar active events that have a direct influence on the near-Earth space weather.

  12. Prototype tests for the CELESTE solar array gamma-ray telescope

    International Nuclear Information System (INIS)

    The CELESTE experiment will be an atmospheric Cherenkov detector designed to bridge the gap in energy sensitivity between current satellite and ground-based gamma-ray telescopes, 20-300 GeV. We present test results made at the former solar power plant, Themis, in the French Pyrenees. The tests confirm the viability of using a central tower heliostat array for Cherenkov wavefront sampling. (orig.)

  13. Prototype Tests for the CELESTE Solar Array $\\gamma$-Ray Telescope

    CERN Document Server

    Giebels, B; Bergeret, H; Cordier, A; Debiais, G; De Naurois, Mathieu; Dezalay, J P; Dumora, D; Eschstruth, P T; Espigat, P; Fabre, B; Fleury, P; Ghesquière, C; Herault, N; Malet, I; Merkel, B; Meynadier, C; Palatka, M; Paré, E; Procureur, J; Punch, M; Québert, J; Ragan, K; Rob, L; Schovanek, P; Smith, D A; Vrana, J

    1998-01-01

    The CELESTE experiment will be an Atmospheric Cherenkov detector designed to bridge the gap in energy sensitivity between current satellite and ground-based gamma-ray telescopes, 20 to 300 GeV. We present test results made at the former solar power plant, Themis, in the French Pyrenees. The tests confirm the viability of using a central tower heliostat array for Cherenkov wavefront sampling.

  14. Prototype Tests for the CELESTE Solar Array Gamma--Ray Telescope

    OpenAIRE

    Giebels, B.; Bazer-Bachi, R.; Bergeret, H.; Cordier, A.; Debiais, G.; de Naurois, M.; Dezalay, J. P.; Dumora, D.; Eschstruth, P.; Espigat, P.; Fabre, B.; Fleury, P.; Ghesquière, C.; Herault, N.; Malet, I.

    1998-01-01

    The CELESTE experiment will be an Atmospheric Cherenkov detector designed to bridge the gap in energy sensitivity between current satellite and ground-based gamma-ray telescopes, 20 to 300 GeV. We present test results made at the former solar power plant, Themis, in the French Pyrenees. The tests confirm the viability of using a central tower heliostat array for Cherenkov wavefront sampling.

  15. Prospects for Detection of Extra-Solar Giant Planets by Next-Generation Telescopes

    OpenAIRE

    Burrows, A.; D. Saumon; Guillot, T.; Hubbard, W. B.; Lunine, J. I.

    1995-01-01

    Interest among astronomers in the detection of extra-solar planets is accelerating with the growing realization that it may soon be technically feasible. The ongoing renaissance in telescope construction and the anticipated launches of new space platforms are encouraging many scientists to review and improve the means by which planets can be discovered. The direct detection of the light from a distant planet would be the most compelling means of discovery and to gauge the feasibility of vario...

  16. Neutrino and axion hot dark matter bounds after WMAP-7

    International Nuclear Information System (INIS)

    We update cosmological hot dark matter constraints on neutrinos and hadronic axions. Our most restrictive limits use 7-year data from the Wilkinson Microwave Anisotropy Probe for the cosmic microwave background anisotropies, the halo power spectrum (HPS) from the 7th data release of the Sloan Digital Sky Survey, and the Hubble constant from Hubble Space Telescope observations. We find 95% CL upper limits of Σmν a ν = 0), and Σmν a ν a constraints. This difference can be traced to the fact that for a given hot dark matter fraction axions are much more massive than neutrinos

  17. The X-ray mirror telescope and the pn-CCD detector of CAST

    CERN Document Server

    Kuster, M; Englhauser, J; Franz, J; Friedrich, P; Hartmann, R; Kang, D; Kotthaus, R; Lutz, Gerhard; Moralez, J; Serber, W; Strüder, L

    2004-01-01

    The Cern Axion Solar Telescope - CAST - uses a prototype 9 Tesla LHC superconducting dipole magnet to search for a hypothetical pseudoscalar particle, the axion, which was proposed by theory in the 1980s to solve the strong CP problem and which could be a dark matter candidate. In CAST a strong magnetic field is used to convert the solar axions to detectable photons via inverse Primakoff effect. The resulting X-rays are thermally distributed in the energy range of 1-7 keV and can be observed with conventional X-ray detectors. The most sensitive detector system of CAST is a pn-CCD detector originally developed for XMM-Newton combined with a Wolter I type X-ray mirror system. The combination of a focusing X-ray optics and a state of the art pn-CCD detector which combines high quantum efficiency, good spacial and energy resolution, and low background improves the sensitivity of the CAST experiment such that for the first time the axion photon coupling constant can be probed beyond the best astrophysical constrai...

  18. First Axion Results from the XENON100 Experiment

    CERN Document Server

    Aprile, E.; Alfonsi, M.; Arisaka, K.; Arneodo, F.; Auger, M.; Balan, C.; Barrow, P.; Baudis, L.; Bauermeister, B.; Behrens, A.; Beltrame, P.; Bokeloh, K.; Brown, A.; Brown, E.; Bruenner, S.; Bruno, G.; Budnik, R.; Cardoso, J.M.R.; Colijn, A.P.; Contreras, H.; Cussonneau, J.P.; Decowski, M.P.; Duchovni, E.; Fattori, S.; Ferella, A.D.; Fulgione, W.; Gao, F.; Garbini, M.; Geis, C.; Goetzke, L.W.; Grignon, C.; Gross, E.; Hampel, W.; Itay, R.; Kaether, F.; Kessler, G.; Kish, A.; Landsman, H.; Lang, R.F.; Calloch, M. Le; Lellouch, D.; Levy, C.; Lindemann, S.; Lindner, M.; Lopes, J.A.M.; Lung, K.; Lyashenko, A.; Macmullin, S.; Marrodan Undagoitia, T.; Masbou, J.; Massoli, F.V.; Mayani Paras, D.; Melgarejo Fernandez, A. J.; Meng, Y.; Messina, M.; Miguez, B.; Molinario, A.; Murra, M.; Naganoma, J.; Oberlack, U.; Orrigo, S.E.A.; Pantic, E.; Persiani, R.; Piastra, F.; Pienaar, J.; Plante, G.; Priel, N.; Reichard, S.; Reuter, C.; Rizzo, A.; Rosendahl, S.; dos Santos, J. M. F.; Sartorelli, G.; Schindler, S.; Schreiner, J.; Schumann, M.; Scotto Lavina, L.; Selvi, M.; Shagin, P.; Simgen, H.; Teymourian, A.; Thers, D.; Tiseni, A.; Trinchero, G.; Vitells, O.; Wang, H.; Weber, M.; Weinheimer, C.

    2014-01-01

    We present the first results of searches for axions and axion-like-particles with the XENON100 experiment. The axion-electron coupling constant, $g_{Ae}$, has been tested by exploiting the axio-electric effect in liquid xenon. A profile likelihood analysis of 224.6 live days $\\times$ 34 kg exposure has shown no evidence for a signal. By rejecting $g_{Ae}$, larger than $7.7 \\times 10^{-12}$ (90% CL) in the solar axion search, we set the best limit to date on this coupling. In the frame of the DFSZ and KSVZ models, we exclude QCD axions heavier than 0.3 eV/c$^2$ and 80 eV/c$^2$, respectively. For axion-like-particles, under the assumption that they constitute the whole abundance of dark matter in our galaxy, we constrain $g_{Ae}$, to be lower than $1 \\times 10^{-12}$ (90% CL) for masses between 5 and 10 keV/c$^2$.

  19. Cosmological Consequences of String Axions

    International Nuclear Information System (INIS)

    Axion fluctuations generated during inflation lead to isocurvature and non-Gaussian temperature fluctuations in the cosmic microwave background radiation. Following a previous analysis for the model independent string axion we consider the consequences of a measurement of these fluctuations for two additional string axions. We do so independent of any cosmological assumptions except for the axions being massless during inflation. The first axion has been shown to solve the strong CP problem for most compactifications of the heterotic string while the second axion, which does not solve the strong CP problem, obeys a mass formula which is independent of the axion scale. We find that if gravitational waves interpreted as arising from inflation are observed by the PLANCK polarimetry experiment with a Hubble constant during inflation of Hinf ∼> 1013 GeV the existence of the first axion is ruled out and the second axion cannot obey the scale independent mass formula. In an appendix we quantitatively justify the often held assumption that temperature corrections to the zero temperature QCD axion mass may be ignored for temperatures T ∼QCD

  20. The Lifetime of Axion Stars

    CERN Document Server

    Eby, Joshua; Wijewardhana, L C R

    2015-01-01

    We investigate the decay of condensates of scalars in a field theory defined by $V({\\cal A})=m^2 f^2 [1-\\cos({\\cal A}/f)]$, where $m$ and $f$ are the mass and decay constant of the scalar field. An example of such a theory is that of the axion, in which case the condensates are called axion stars. The axion field, $\\cal A$, is self adjoint. As a result the axion number is not an absolutely conserved quantity. Therefore, axion stars are not stable and have finite lifetimes. Bound axions, localized on the volume of the star, have a coordinate uncertainty $\\Delta x \\sim R \\sim 1/(m_a \\Delta)$, where $R$ is the radius of the star and $\\Delta = \\sqrt{1-E_0^2/m_a^2}$. Here $m_a$ and $E_0$ are the mass and the ground state energy of the bound axion. Then the momentum distribution of axions has a width of $\\Delta p \\sim m_a\\Delta$. At strong binding, $\\Delta={\\cal O}(1)$, bound axions can easily transfer a sufficient amount of momentum to create and emit a free axion, leading to fast decay of the star with a transiti...

  1. Cosmic Axion Bose-Einstein Condensation

    OpenAIRE

    Banik, Nilanjan; Sikivie, Pierre

    2015-01-01

    QCD axions are a well-motivated candidate for cold dark matter. Cold axions are produced in the early universe by vacuum realignment, axion string decay and axion domain wall decay. We show that cold axions thermalize via their gravitational self-interactions, and form a Bose-Einstein condensate. As a result, axion dark matter behaves differently from the other proposed forms of dark matter. The differences are observable.

  2. The Greenwich Photo-heliographic Results (1874 - 1885): Observing Telescopes, Photographic Processes, and Solar Images

    Science.gov (United States)

    Willis, D. M.; Wild, M. N.; Appleby, G. M.; Macdonald, L. T.

    2016-05-01

    Potential sources of inhomogeneity in the sunspot measurements published by the Royal Observatory, Greenwich, during the early interval 1874 - 1885 are examined critically. Particular attention is paid to inhomogeneities that might arise because the sunspot measurements were derived from solar photographs taken at various contributing solar observatories, which used different telescopes, experienced different seeing conditions, and employed different photographic processes. The procedures employed in the Solar Department at the Royal Greenwich Observatory (RGO), Herstmonceux, during the final phase of sunspot observations provide a modern benchmark for interpreting the early sunspot measurements. The different observing telescopes used at the contributing solar observatories during the interval 1874 - 1885 are discussed in detail, using information gleaned from the official RGO publications and other relevant historical documents. Likewise, the different photographic processes employed at the different solar observatories are reviewed carefully. The procedures used by RGO staff to measure the positions and areas of sunspot groups on photographs of the Sun having a nominal radius of either four or eight inches are described. It is argued that the learning curve for the use of the Kew photoheliograph at the Royal Observatory, Greenwich, actually commenced in 1858, not 1874. The RGO daily number of sunspot groups is plotted graphically and analysed statistically. Similarly, the changes of metadata at each solar observatory are shown on the graphical plots and analysed statistically. It is concluded that neither the interleaving of data from the different solar observatories nor the changes in metadata invalidates the RGO count of the number of sunspot groups, which behaves as a quasi-homogeneous time series. Furthermore, it is emphasised that the correct treatment of days without photographs is quite crucial to the correct calculation of Group Sunspot Numbers.

  3. Axion inflation with cross-correlated axion isocurvature perturbations

    Energy Technology Data Exchange (ETDEWEB)

    Kadota, Kenji [Center for Theoretical Physics of the Universe, Institute for Basic Science,Daejeon 305-811 (Korea, Republic of); Kobayashi, Tatsuo [Department of Physics, Hokkaido University,Sapporo 060-0810 (Japan); Otsuka, Hajime [Department of Physics, Waseda University,Tokyo 169-8555 (Japan)

    2016-01-25

    We study the inflation scenarios, in the framework of superstring theory, where the inflaton is an axion producing the adiabatic curvature perturbations while there exists another light axion producing the isocurvature perturbations. We discuss how the non-trivial couplings among string axions can generically arise, and calculate the consequent cross-correlations between the adiabatic and isocurvature modes through concrete examples. Based on the Planck analysis on the generally correlated isocurvature perturbations, we show that there is a preference for the existence of the correlated isocurvature modes for the axion monodromy inflation while the natural inflation disfavors such isocurvature modes.

  4. Axions and SN 1987A

    International Nuclear Information System (INIS)

    We consider the effect of free-streaming axion emission on numerical models for the cooling of the newly born neutron star associated with SN 1987A. We find that for an axion mass of greater than ∼10/sup -3/ eV, axion emission shortens the duration of the expected neutrino burst so significantly that it would be inconsistent with the neutrino observations made by the Kamiokande II and Irvine-Michigan-Brookhaven detectors. However, we have not investigated the possibility that axion trapping (which should occur for masses ≥0.02 eV) sufficiently reduces axion emission so that axion masses greater than ∼2 eV would be consistent with the neutrino observations

  5. Axions and SN1987A

    International Nuclear Information System (INIS)

    The effect of free-streaming axion emission on numerical models for the cooling of the newly born neutron star associated with SN1987A is considered. It is found that for an axion mass of greater than approximately 10 to the -3 eV, axion emission shortens the duration of the expected neutrino burst so significantly that it would be inconsistent with the neutrino observations made by the Kamiokande II and Irvine-Michigan-Brookhaven detectors. However, the possibility has not been investigated that axion trapping (which should occur for masses greater than or equal to 0.02 eV) sufficiently reduces axion emission so that axion masses greater than approximately 2 eV would be consistent with the neutrino observations

  6. Axions and the anthropic principle

    International Nuclear Information System (INIS)

    We consider the possibility that the axion density in the Universe today may be constrained by the anthropic requirement that life should have evolved. If this were the case, the force of the usual cosmological bound on the axion decay constant would be greatly lessened. However, we find no mechanism by which excessive axion energy density could prevent the condensation of matter into potentially life-nurturing structures

  7. Construction Status and Early Science with the Daniel K. Inouye Solar Telescope

    Science.gov (United States)

    McMullin, Joseph P.; Rimmele, Thomas R.; Warner, Mark; Martinez Pillet, Valentin; Craig, Simon; Woeger, Friedrich; Tritschler, Alexandra; Berukoff, Steven J.; Casini, Roberto; Goode, Philip R.; Knoelker, Michael; Kuhn, Jeffrey Richard; Lin, Haosheng; Mathioudakis, Mihalis; Reardon, Kevin P.; Rosner, Robert; Schmidt, Wolfgang

    2016-05-01

    The 4-m Daniel K. Inouye Solar Telescope (DKIST) is in its seventh year of overall development and its fourth year of site construction on the summit of Haleakala, Maui. The Site Facilities (Utility Building and Support & Operations Building) are in place with ongoing construction of the Telescope Mount Assembly within. Off-site the fabrication of the component systems is completing with early integration testing and verification starting.Once complete this facility will provide the highest sensitivity and resolution for study of solar magnetism and the drivers of key processes impacting Earth (solar wind, flares, coronal mass ejections, and variability in solar output). The DKIST will be equipped initially with a battery of first light instruments which cover a spectral range from the UV (380 nm) to the near IR (5000 nm), and capable of providing both imaging and spectro-polarimetric measurements throughout the solar atmosphere (photosphere, chromosphere, and corona); these instruments are being developed by the National Solar Observatory (Visible Broadband Imager), High Altitude Observatory (Visible Spectro-Polarimeter), Kiepenheuer Institute (Visible Tunable Filter) and the University of Hawaii (Cryogenic Near-Infrared Spectro-Polarimeter and the Diffraction-Limited Near-Infrared Spectro-Polarimeter). Further, a United Kingdom consortium led by Queen's University Belfast is driving the development of high speed cameras essential for capturing the highly dynamic processes measured by these instruments. Finally, a state-of-the-art adaptive optics system will support diffraction limited imaging capable of resolving features approximately 20 km in scale on the Sun.We present the overall status of the construction phase along with the current challenges as well as a review of the planned science testing and the transition into early science operations.

  8. Calibration development strategies for the Daniel K. Inouye Solar Telescope (DKIST) Data Center

    Science.gov (United States)

    Watson, Fraser; Reardon, Kevin P.; Berukoff, Steven J.; Hays, Tony; Wiant, Scott; Spiess, DJ

    2016-05-01

    As telescopes have grown larger and data rates have increased, so have the challenges in providing reliable and accurate calibration strategies for transforming raw data into useful science-ready outputs. The Daniel K. Inouye Solar Telescope (DKIST) will be the largest solar telescope in the world and will use adaptive optics to provide the highest resolution view of the Sun. Its data acquisition rates will be in the hundreds of thousands of frames per day, and it will deliver an average of 12TB of raw solar data on a daily basis. DKIST data will enable significant and transformative discoveries that will dramatically increase our understanding of the Sun and its effects on the Sun-Earth environment. As such, it is a priority of the DKIST Data Center team at the National Solar Observatory (NSO) to be able to deliver timely and accurately calibrated data to the astronomical community for further analysis.The facility will execute a variety of investigator-driven observing programs, which will produce day–to-day variations in the types of acquired data. In combination with large data rates and limited personnel, this will require some degree of automation to be incorporated into the calibration workflows to facilitate the generation of scientifically useful data. The heterogeneity of the data and the unpredictable variations in the seeing conditions (on timescales of seconds or minutes) introduce complexity, which requires a self-adapting, extensible calibration pipeline to provide sufficient automation to the process. Our knowledge of the instrument performance and telescope characteristics will grow as the telescope begins operations, and continuously through the facility lifetime. The automated calibration pipelines will be capable of modification and improvement to incorporate the new information about the DKIST system, as well as potential improvements provided by the DKIST user community.This poster will detail the calibration development strategies being

  9. Reflectivity, polarization properties, and durability of metallic mirror coatings for the European Solar Telescope

    Science.gov (United States)

    Feller, A.; Krishnappa, N.; Pleier, O.; Hirzberger, J.; Jobst, P. J.; Schürmann, M.

    2012-09-01

    In the context of the conceptual design study for the European Solar Telescope (EST) we have investigated different metallic mirror coatings in terms of reflectivity, polarization properties and durability. Samples of the following coating types have been studied: bare aluminum, silver with different dielectric layers for protection and UV enhancement, and an aluminum-silver combination. From 2009 to 2011 we have carried out a long-term durability test under realistic observing conditions at the VTT solar telescope of the Observatorio del Teide (Tenerife, Spain), accompanied by repeated reflectivity measurements in the EST spectral working range (0.3 - 20 μm), and by polarization measurements in the visible range. The test results allow us to find the optimum coatings for the different mirrors in the EST beampath and to eventually assess aging effects and re-coating cycles. The results of the polarization measurements are a valuable input for an EST telescope polarization model, helping to meet the stringent requirements on polarimetric accuracy.

  10. High-performance parallel image reconstruction for the New Vacuum Solar Telescope

    Science.gov (United States)

    Li, Xue-Bao; Liu, Zhong; Wang, Feng; Jin, Zhen-Yu; Xiang, Yong-Yuan; Zheng, Yan-Fang

    2015-06-01

    Many technologies have been developed to help improve spatial resolution of observational images for ground-based solar telescopes, such as adaptive optics (AO) systems and post-processing reconstruction. As any AO system correction is only partial, it is indispensable to use post-processing reconstruction techniques. In the New Vacuum Solar Telescope (NVST), a speckle-masking method is used to achieve the diffraction-limited resolution of the telescope. Although the method is very promising, the computation is quite intensive, and the amount of data is tremendous, requiring several months to reconstruct observational data of one day on a high-end computer. To accelerate image reconstruction, we parallelize the program package on a high-performance cluster. We describe parallel implementation details for several reconstruction procedures. The code is written in the C language using the Message Passing Interface (MPI) and is optimized for parallel processing in a multiprocessor environment. We show the excellent performance of parallel implementation, and the whole data processing speed is about 71 times faster than before. Finally, we analyze the scalability of the code to find possible bottlenecks, and propose several ways to further improve the parallel performance. We conclude that the presented program is capable of executing reconstruction applications in real-time at NVST.

  11. On the use of Cherenkov Telescopes for outer Solar system body occultations

    Science.gov (United States)

    Lacki, Brian C.

    2014-12-01

    Imaging Atmospheric Cherenkov Telescopes (IACTs) are arrays of very large optical telescopes that are well-suited for rapid photometry of bright sources. I investigate their potential in observing stellar occultations by small objects in the outer Solar system, Transjovian Objects (TJOs). These occultations cast diffraction patterns on the Earth. Current IACT arrays are capable of detecting objects smaller than 100 m in radius in the Kuiper Belt and 1 km radius out to 5000 au. The future Cherenkov Telescope Array (CTA) will have even greater capabilities. Because the arrays include several telescopes, they can potentially measure the speeds of TJOs without degeneracies, and the sizes of the TJOs and background stars. I estimate the achievable precision using a Fisher matrix analysis. With CTA, the precisions of these parameter estimations will be as good as a few per cent. I consider how often detectable occultations occur by members of different TJO populations, including Centaurs, Kuiper Belt Objects (KBOs), Oort Cloud objects, and satellites and Trojans of Uranus and Neptune. The great sensitivity of IACT arrays means that they likely detect KBO occultations once every O(10) hours when looking near the ecliptic. IACTs can also set useful limits on many other TJO populations.

  12. Unprecedented Fine Structure of a Solar Flare Revealed by the 1.6 m New Solar Telescope.

    Science.gov (United States)

    Jing, Ju; Xu, Yan; Cao, Wenda; Liu, Chang; Gary, Dale; Wang, Haimin

    2016-01-01

    Solar flares signify the sudden release of magnetic energy and are sources of so called space weather. The fine structures (below 500 km) of flares are rarely observed and are accessible to only a few instruments world-wide. Here we present observation of a solar flare using exceptionally high resolution images from the 1.6 m New Solar Telescope (NST) equipped with high order adaptive optics at Big Bear Solar Observatory (BBSO). The observation reveals the process of the flare in unprecedented detail, including the flare ribbon propagating across the sunspots, coronal rain (made of condensing plasma) streaming down along the post-flare loops, and the chromosphere's response to the impact of coronal rain, showing fine-scale brightenings at the footpoints of the falling plasma. Taking advantage of the resolving power of the NST, we measure the cross-sectional widths of flare ribbons, post-flare loops and footpoint brighenings, which generally lie in the range of 80-200 km, well below the resolution of most current instruments used for flare studies. Confining the scale of such fine structure provides an essential piece of information in modeling the energy transport mechanism of flares, which is an important issue in solar and plasma physics. PMID:27071459

  13. Unprecedented Fine Structure of a Solar Flare Revealed by the 1.6~m New Solar Telescope

    Science.gov (United States)

    Jing, Ju; Xu, Yan; Cao, Wenda; Liu, Chang; Gary, Dale E.; Wang, Haimin

    2016-05-01

    Solar flares signify the sudden release of magnetic energy and are sources of so called space weather. The fine structures (below 500 km) of flares are rarely observed and are accessible to only a few instruments world-wide. Here we present observation of a solar flare using exceptionally high resolution images from the 1.6~m New Solar Telescope (NST) equipped with high order adaptive optics at Big Bear Solar Observatory (BBSO). The observation reveals the process of the flare in unprecedented detail, including the flare ribbon propagating across the sunspots, coronal rain (made of condensing plasma) streaming down along the post-flare loops, and the chromosphere's response to the impact of coronal rain, showing fine-scale brightenings at the footpoints of the falling plasma. Taking advantage of the resolving power of the NST, we measure the cross-sectional widths of flare ribbons, post-flare loops and footpoint brighenings, which generally lie in the range of 80-200 km, well below the resolution of most current instruments used for flare studies. Confining the scale of such fine structure provides an essential piece of information in modeling the energy transport mechanism of flares, which is an important issue in solar and plasma physics.

  14. Lightweight tip-tilt mirror in correlation tracker system of the Space Solar Telescope

    Science.gov (United States)

    Zhang, Rui; Yang, Shimo; Jiang, Aimin

    2005-12-01

    To compensate the image motion caused by random atmospheric turbulence and mechanical vibration, a high performance correlation tracker designed for the Space Solar Telescope (SST) has been realized in National Astronomical Observatories. Correlation tracker is to stabilize the image and provide the stabilized objective to CCD. The main optical telescope can obtain the highest spatial resolution and ensure the image processing. Tip-tilt mirror is the crucial element of the correlation tracker. The lightweight mirror is to adapt to work normally with space using and satisfy the space environmental requirement. Tip-tilt mirror's material is SiC. Confirming the appropriate joint with the platform and supporting mode through Finite Element Method. Then calculating the surface shape quality value (RMS) of the mirror effected by inertial load and temperature. The calculation results show that the tip-tilt mirror has enough stiffness and intensity. The mirror's surface shape quality value can satisfy the optical requirement of the correlation tracker system.

  15. The current status of model development of the electron and proton telescope for Solar Orbiter

    International Nuclear Information System (INIS)

    ESA's Solar Orbiter mission, scheduled for launch in January 2017, will study how the sun creates the inner heliosphere. Therefore, the spacecraft will perform in situ and remote sensing measurements of the sun on a high inclination orbit with a perihelion of about 60 solar radii, making it possible to observe the poles of the sun from nearby. The Energetic Particle Detector suite on-board of Solar Orbiter will measure particles of a wide energy range and from multiple directions. One of the important sensors of the EPD suite is the Electron Proton Telescope. It consists of two antiparallel telescopes with two silicon detectors respectively and is designed to detect electrons between 20 - 400 keV and protons from 20 keV to 7 MeV. EPT relies on a magnet/foil technique to discriminate between electrons and protons. Here, we present the testing of the Structural and Thermal Model, which has already been delivered to ASTRIUM for spacecraft level tests as well as the integration and testing of the Engineering Model, which already provides full electrical functionality.

  16. Capabilities of the Thirty-Meter Telescope (TMT) for Solar System Astronomy

    Science.gov (United States)

    Otarola, Angel; Dumas, Christophe; Meech, Karen; Sekiguchi, Tomohiko; Skidmore, Warren; Tian, Feng; Travouillon, Tony; Wong, Michael H.; Ellerbroek, Brent; Simard, Luc

    2015-11-01

    The TMT will consist of a 30-m filled-aperture segmented primary mirror and will include non-sidereal rate tracking capabilities for observing Solar System objects. Its sensitivity will be 14 times larger than that of 8-m class telescopes for seeing-limited observations -up to 200 times larger for background limited adaptive optics (AO) observations- and will allow high angular/spatial resolution with diffraction-limited capability in the near infrared. AO guiding will accommodate faint, small angular size solar system objects to serve as natural guide stars for non-sidereal observations. For Kuiper belt objects (KBOs), on-instrument wavefront sensors can crawl the field-of-view to look for background natural stars that can be used for tip/tilt correction. We will describe the main characteristics of the Thirty Meter Telescope, its first light instrumentation suite, and the most relevant science-driven requirements for its design, emphasizing the strengths of the TMT for Solar System astronomical research. Some real-case scenarios of sensitivities for solar system targets will be presented for the first-light instruments.Complementary information about TMT, and the opportunities it offers for planetary science research, will be presented at this meeting by Dumas et al., and at the TMT Solar System Town Hall event on Tuesday.The international TMT partnership includes Canada, China, India, Japan, Caltech, the University of California, and Funding is also provided by the Gordon and Betty Moore Foundation. AURA is an Associate Member of TMT on behalf of the US national community. Through a cooperative agreement with the NSF, TMT and a US TMT Science Working Group are developing a model for potential US national partnership in the TMT.

  17. The QCD axion from aligned axions and diphoton excess

    Directory of Open Access Journals (Sweden)

    Tetsutaro Higaki

    2016-04-01

    Full Text Available We argue that the QCD axion can arise from many aligned axions with decay constants much smaller than the conventional axion window. If the typical decay constant is of O(100 GeV to 1 TeV, one or more of the axions or saxions may account for the recently found diphoton excess at ∼750 GeV. Our scenario predicts many axions and saxions coupled to gluons with decay constants of order the weak scale, and therefore many collider signatures by heavy axions and saxions will show up at different energy scales. In particular, if the inferred broad decay width is due to multiple axions or saxions, a non-trivial peak structure may become evident when more data is collected. We also discuss cosmological implications of the aligned QCD axion scenario. In the Appendix we give a possible UV completion and argue that the high quality of the Peccei–Quinn symmetry is naturally explained in our scenario.

  18. Axion phantom energy

    OpenAIRE

    González-Díaz, Pedro F.

    2004-01-01

    The existence of phantom energy in a universe which evolves to eventually show a big rip doomsday is a possibility which is not excluded by present observational constraints. In this paper it is argued that the field theory associated with a simple quintessence model is compatible with a field definition that is interpretable in terms of a rank-3 axionic tensor field, whenever we consider a perfect-fluid equation of state that corresponds to the phantom energy regime. Explicit expressions for...

  19. Magnetogenesis from axion inflation

    CERN Document Server

    Adshead, Peter; Scully, Timothy R; Sfakianakis, Evangelos I

    2016-01-01

    In this work we compute the production of magnetic fields in models of axion inflation coupled to the hypercharge sector of the Standard Model through a Chern-Simons interaction term. We make the simplest choice of a quadratic inflationary potential and use lattice simulations to calculate the magnetic field strength, helicity and correlation length at the end of inflation. For small values of the axion-gauge field coupling strength the results agree with no-backreaction calculations and estimates found in the literature. For larger couplings the helicity of the magnetic field differs from the no-backreaction estimate and depends strongly on the comoving wavenumber. We estimate the post-inflationary evolution of the magnetic field based on known results for the evolution of helical and non-helical magnetic fields. The magnetic fields produced by axion inflation with large couplings to $U(1)_Y$ can reach $B_{\\rm eff} \\gtrsim 10^{-16}\\, G$. This result is insensitive to the exact value of the coupling, as long ...

  20. Level Crossing between QCD Axion and Axion-Like Particle

    CERN Document Server

    Daido, Ryuji; Takahashi, Fuminobu

    2015-01-01

    We study a level crossing between the QCD axion and an axion-like particle, focusing on the recently found phenomenon, the axion roulette, where the axion-like particle runs along the potential, passing through many crests and troughs, until it gets trapped in one of the potential minima. We perform detailed numerical calculations to determine the parameter space where the axion roulette takes place, and as a result domain walls are likely formed. The domain wall network without cosmic strings is practically stable, and it is nothing but a cosmological disaster. In a certain case, one can make domain walls unstable and decay quickly by introducing an energy bias without spoiling the Peccei-Quinn solution to the strong CP problem.

  1. A Novel Lateral Deployment Mechanism for Segmented Mirror/Solar Panel of Space Telescope

    Science.gov (United States)

    Thesiya, Dignesh; Srinivas, A. R.; Shukla, Piyush

    2015-09-01

    Space telescopes require large aperture primary mirrors to capture High Definition (HD) ground image while orbiting around the Earth. Fairing Volume of launch vehicles is limited and thus the size of monolithic mirror is limited to fairing size and solar panels are arranged within a petal formation in order to provide a greater power to volume ratio. This generates need for deployable mirrors for space use. This brings out a method for designing new deployment mechanism for segmented mirror. Details of mechanism folding strategy, design of components, FE simulations, realization and Lab model validation results are discussed in order to demonstrate the design using prototype.

  2. Advanced Scintillator-Based Compton Telescope for Solar Flare Gamma-Ray Measurements

    Science.gov (United States)

    Ryan, James Michael; Bloser, Peter; McConnell, Mark; Legere, Jason; Bancroft, Christopher; Murphy, Ronald; de Nolfo, Georgia

    2015-04-01

    A major goal of future Solar and Heliospheric Physics missions is the understanding of the particle acceleration processes taking place on the Sun. Achieving this understanding will require detailed study of the gamma-ray emission lines generated by accelerated ions in solar flares. Specifically, it will be necessary to study gamma-ray line ratios over a wide range of flare intensities, down to small C-class flares. Making such measurements over such a wide dynamic range, however, is a serious challenge to gamma-ray instrumentation, which must deal with large backgrounds for faint flares and huge counting rates for bright flares. A fast scintillator-based Compton telescope is a promising solution to this instrumentation challenge. The sensitivity of Compton telescopes to solar flare gamma rays has already been demonstrated by COMPTEL, which was able to detect nuclear emission from a C4 flare, the faintest such detection to date. Modern fast scintillators, such as LaBr3, and CeBr3, are efficient at stopping MeV gamma rays, have sufficient energy resolution (4% or better above 0.5 MeV) to resolve nuclear lines, and are fast enough (~15 ns decay times) to record at very high rates. When configured as a Compton telescope in combination with a modern organic scintillator, such as p-terphenyl, sub-nanosecond coincidence resolving time allows dramatic suppression of background via time-of-flight (ToF) measurements, allowing both faint and bright gamma-ray line flares to be measured. The use of modern light readout devices, such as silicon photomultipliers (SiPMs), eliminates passive mass and permits a more compact, efficient instrument. We have flown a prototype Compton telescope using modern fast scintillators with SiPM readouts on a balloon test flight, achieving good ToF and spectroscopy performance. A larger balloon-borne instrument is currently in development. We present our test results and estimates of the solar flare sensitivity of a possible full-scale instrument

  3. Unprecedented Fine Structure of a Solar Flare Revealed by the 1.6~m New Solar Telescope

    CERN Document Server

    Jing, Ju; Cao, Wenda; Liu, Chang; Gary, Dale; Wang, Haimin

    2016-01-01

    Solar flares signify the sudden release of magnetic energy and are sources of so called space weather. The fine structures (below 500 km) of flares are rarely observed and are accessible to only a few instruments world-wide. Here we present observation of a solar flare using exceptionally high resolution images from the 1.6~m New Solar Telescope (NST) equipped with high order adaptive optics at Big Bear Solar Observatory (BBSO). The observation reveals the process of the flare in unprecedented detail, including the flare ribbon propagating across the sunspots, coronal rain (made of condensing plasma) streaming down along the post-flare loops, and the chromosphere's response to the impact of coronal rain, showing fine-scale brightenings at the footpoints of the falling plasma. Taking advantage of the resolving power of the NST, we measure the cross-sectional widths of flare ribbons, post-flare loops and footpoint brighenings, which generally lie in the range of 80-200 km, well below the resolution of most curr...

  4. Analysis of Flows Inside Quiescent Prominences as Captured by Hinode/Solar Optical Telescope

    CERN Document Server

    Freed, M S; Longcope, D W; Wilburn, M

    2016-01-01

    Developing an understanding of how magnetic fields can become entangled in a prominence is important for predicting a possible eruption. This work investigates the kinetic energy and vorticity associated with plasma motion residing inside quiescent prominences (QPs). These plasma flow characteristics can be utilized to improve our understanding of how the prominence maintains a stable magnetic field configuration. Three different contrast-enhanced solar prominence observations from Hinode/Solar Optical Telescope were used to construct velocity maps -- in the plane of the sky -- via a Fourier local correlation tracking program. The resulting velocities were then used to perform the first ever analysis of the two-dimensional kinetic energy and enstrophy spectra of a prominence. Enstrophy is introduced here as a means of quantifying the vorticity that has been observed in many QPs. The kinetic energy power spectral density (PSD) produced indices ranging from -1.00 to -1.60. There was a consistent anisotropy in t...

  5. Expected Sensitivity to Galactic/Solar Axions and Bosonic Super-WIMPs based on the Axio-electric Effect in Liquid Xenon Dark Matter Detectors

    CERN Document Server

    Arisaka, K; Ghag, C; Kaidi, J; Lung, K; Lyashenko, A; Peccei, R D; Smith, P; Ye, K

    2012-01-01

    We present systematic case studies to investigate the sensitivity of axion searches by liquid xenon detectors, using the axio-electric effect (analogue of the photoelectric effect) on xenon atoms. Liquid xenon is widely considered to be one of the best target media for detection of WIMPs (Weakly Interacting Massive Particles which may form the galactic dark matter) using nuclear recoils. Since these detectors also provide an extremely low radioactivity environment for electron recoils, very weakly-interacting low-mass particles ( 10^-33 (for mass 1 keV/c^2) or > 10^-27 (for mass 100 keV/c^2).

  6. TRANSVERSE OSCILLATIONS OF LOOPS WITH CORONAL RAIN OBSERVED BY HINODE/SOLAR OPTICAL TELESCOPE

    International Nuclear Information System (INIS)

    The condensations composing coronal rain, falling down along loop-like structures observed in cool chromospheric lines such as Hα and Ca II H, have long been a spectacular phenomenon of the solar corona. However, considered a peculiar sporadic phenomenon, it has not received much attention. This picture is rapidly changing due to recent high-resolution observations with instruments such as the Hinode/Solar Optical Telescope (SOT), CRISP of the Swedish 1-m Solar Telescope, and the Solar Dynamics Observatory. Furthermore, numerical simulations have shown that coronal rain is the loss of thermal equilibrium of loops linked to footpoint heating. This result has highlighted the importance that coronal rain can play in the field of coronal heating. In this work, we further stress the importance of coronal rain by showing the role it can play in the understanding of the coronal magnetic field topology. We analyze Hinode/SOT observations in the Ca II H line of a loop in which coronal rain puts in evidence in-phase transverse oscillations of multiple strand-like structures. The periods, amplitudes, transverse velocities, and phase velocities are calculated, allowing an estimation of the energy flux of the wave and the coronal magnetic field inside the loop through means of coronal seismology. We discuss the possible interpretations of the wave as either standing or propagating torsional Alfven or fast kink waves. An estimate of the plasma beta parameter of the condensations indicates a condition that may allow the often observed separation and elongation processes of the condensations. We also show that the wave pressure from the transverse wave can be responsible for the observed low downward acceleration of coronal rain.

  7. Electromagnetic detector for relic axions

    International Nuclear Information System (INIS)

    Axions are particles of small mass postulated to explain CP conservation in strong interactions. The predicted properties of axions provide an explanation for the early clustering of matter into galaxies, the mass in galactic halos, and the missing mass sufficient to close the universe. The interaction of axions with ordinary matter would be extremely weak, but axions should be detectable, because in a strong magnetic field relic axions of mass m/sub a/ would convert into microwave photons with frequency f=m/sub a/c2/h. Predictions for the frequency range from 3 and 24 GHz for relic axions which provide mass density sufficient to close the universe. We propose a laboratory search for relic axions. A specific experimental apparatus is described and system performance is estimated to illustrate the design principles. The microwave signal from axion conversion is produced in a 30 liter microwave cavity which contains dielectric phase shifting plates to give a quality factor (Q) greater than 106, and to provide the correct phasing of the microwave electric field throughout the cavity. The cavity is placed in an 8 Tesla superconducting magnet, and the signal is measured with a conventional microwave receiver employing a GaAs FET rf amplifier or Schottky diode mixer. The cavity, magnet and rf amplifier/mixer will operate at 40K, with noise temperature between 200K and 2000K. The system is equally effective in principle at all frequencies between 1 GHz and 100 GHz at which microwave receivers are available. The corresponding range of axion mass which can be covered is 4x10-6 eV to 4x10-4 eV. A search can be carried out over an octave of frequency in an observation time of three months with sufficient sensitivity to detect axions if they make up the galactic halo

  8. Axion Dark Matter Detection using Atomic Transitions

    CERN Document Server

    Sikivie, P

    2014-01-01

    Dark matter axions may cause transitions between atomic states that differ in energy by an amount equal to the axion mass. Such energy differences are conveniently tuned using the Zeeman effect. It is proposed to search for dark matter axions by cooling a kilogram-sized sample to milliKelvin temperatures and count axion induced transitions using laser techniques. This appears an appropriate approach to axion dark matter detection in the $10^{-4}$ eV mass range.

  9. Cosmological Constant and Axions in String Theory

    Energy Technology Data Exchange (ETDEWEB)

    Svrcek, Peter; /Stanford U., Phys. Dept. /SLAC

    2006-08-18

    String theory axions appear to be promising candidates for explaining cosmological constant via quintessence. In this paper, we study conditions on the string compactifications under which axion quintessence can happen. For sufficiently large number of axions, cosmological constant can be accounted for as the potential energy of axions that have not yet relaxed to their minima. In compactifications that incorporate unified models of particle physics, the height of the axion potential can naturally fall close to the observed value of cosmological constant.

  10. Investigation of intergranular bright points from the New Vacuum Solar Telescope

    CERN Document Server

    Ji, Kai-Fan; Xiang, Yong-yuan; Feng, Song; Deng, Hui; Wang, Feng; Yang, Yun-Fei

    2015-01-01

    Six high-resolution TiO-band image sequences from the New Vacuum Solar Telescope (NVST) are used to investigate the properties of intergranular bright points (igBPs). We detect the igBPs using a Laplacian and morphological dilation algorithm (LMD) and track them using a three-dimensional segmentation algorithm automatically, and then investigate the morphologic, photometric and dynamic properties of igBPs, in terms of equivalent diameter, the intensity contrast, lifetime, horizontal velocity, diffusion index, motion range and motion type. The statistical results confirm the previous studies based on G-band or TiO-band igBPs from the other telescopes. It illustrates that the TiO data from the NVST have a stable and reliable quality, which are suitable for studying the igBPs. In addition, our method is feasible to detect and track the igBPs in the TiO data from the NVST. With the aid of the vector magnetograms obtained from the Solar Dynamics Observatory /Helioseismic and Magnetic Imager, the properties of igBP...

  11. Calculating particle spectra from the solar electron and proton telescope onboard STEREO

    International Nuclear Information System (INIS)

    STEREO (Solar TErrestrial RElations Observatory) was launched on October 26, 2006. It consists of two spacecraft on heliocentric orbits, one preceding the Earth, the other following it. The Solar Electron and Proton Telescope (SEPT) onboard each of the two spacecraft is made up of two dual double-ended magnetic/foil particle telescopes which separate and measure electrons (from 30 to 400 keV) and ions, mainly protons and α-particles (from 70 keV to 2.2 MeV). Low energy ions are stopped by the thin foil which electrons can pass with an essentially unaltered spectrum. The magnet on the other side deflects electrons while ions still reach the detector. Up to now, SEPT energy spectra were obtained using defined energy channels from accelerator calibration measurements and geometric factors derived from Monte Carlo simulations. We try a different approach, applying inversion methods to calculate the energy spectra from the measurements, expecting higher accuracy and better separation of the different particle populations.

  12. Muon bursts at the Baksan Underground Scintillation Telescope during energetic solar phenomena

    International Nuclear Information System (INIS)

    An extended study is performed of short-term bursts of muon intensity recorded at the Baksan Underground Scintillation Telescope (BUST) in 1981-1992. The bursts may be caused by primary protons with energy Ep>500 GeV. The paper summarizes the results of data analysis obtained during 18 Ground Level Enhancements (GLE) of solar cosmic rays (SCR). It is proved that at least three of the most significant bursts are associated, with a high probability, with the GLE's of September 29, 1989, June 15, 1991, and October 12, 1981. There are definite evidences that some of 15 other bursts seem to be also associated with energetic solar phenomena-large flares, coronal mass ejections (CME), solar proton events (SPE), etc. Otherwise, it is difficult to explain significant distinctions of their angular and temporal properties from the noise ones. The results make the very specific, strict requirements to possible particle source(s), acceleration and propagation mechanisms. The effect under discussion ('BUST effect') is suggested to be closely linked with some powerful processes at the Sun, implying possible impact of extended coronal structures, post-eruption energy release, CMEs and coronal (interplanetary) shocks on solar particle acceleration or modulation of galactic cosmic rays (GCR)

  13. Photometry's bright future: Detecting Solar System analogues with future space telescopes

    CERN Document Server

    Hippke, Michael

    2015-01-01

    Time-series transit photometry from the Kepler space telescope has allowed for the discovery of thousands of exoplanets. We explore the potential of yet improved future missions such as PLATO 2.0 in detecting solar system analogues. We use real-world solar data and end-to-end simulations to explore the stellar and instrumental noise properties. By injecting and retrieving planets, rings and moons of our own solar system, we show that the discovery of Venus- and Earth-analogues transiting G-dwarfs like our Sun is feasible at high S/N after collecting 6yrs of data, but Mars and Mercury will be difficult to detect due to stellar noise. In the best cases, Saturn's rings and Jupiter's moons will be detectable even in single transit observations. Through the high number (>1bn) of observed stars by PLATO 2.0, it will become possible to detect thousands of single-transit events by cold gas giants, analogue to our Jupiter, Saturn, Uranus and Neptune. Our own solar system aside, we also show, through signal injection a...

  14. Photometry’s Bright Future: Detecting Solar System Analogs with Future Space Telescopes

    Science.gov (United States)

    Hippke, Michael; Angerhausen, Daniel

    2015-09-01

    Time-series transit photometry from the Kepler space telescope has allowed for the discovery of thousands of exoplanets. We explore the potential of yet improved future missions such as PLATO 2.0 in detecting solar system analogs. We use real-world solar data and end-to-end simulations to explore the stellar and instrumental noise properties. By injecting and retrieving planets, rings, and moons of our own solar system, we show that the discovery of Venus and Earth analogs transiting G dwarfs like our Sun is feasible at high signal-to-noise ratio after collecting 6 yr of data, but Mars and Mercury analogs will be difficult to detect owing to stellar noise. In the best cases, Saturn’s rings and Jupiter’s moons will be detectable even in single-transit observations. Through the high number (>1 billion) of observed stars by PLATO 2.0, it will become possible to detect thousands of single-transit events by cold gas giants, analogs to our Jupiter, Saturn, Uranus, and Neptune. Our own solar system aside, we also show, through signal injection and retrieval, that PLATO 2.0 class photometry will allow for the secure detection of exomoons transiting quiet M dwarfs. This is the first study analyzing in depth the potential of future missions and the ultimate limits of photometry, using realistic case examples.

  15. Axionic mirage mediation

    International Nuclear Information System (INIS)

    Although mirage mediation is one of the most plausible mediation mechanisms of supersymmetry breaking, it suffers from two crucial problems. One is the μ/Bμ problem, and the second is the cosmological one. The former stems from the fact that the B parameter tends to be comparable with the gravitino mass, which is 2 orders of magnitude larger than the other soft masses. The latter problem is caused by the decay of the modulus whose branching ratio into the gravitino pair is sizable. In this paper, we propose a model of mirage mediation, in which Peccei-Quinn symmetry is incorporated. In this axionic mirage mediation, it is shown that the Peccei-Quinn symmetry breaking scale is dynamically determined around 1010 GeV to 1012 GeV due to the supersymmetry breaking effects, and the μ problem can be solved naturally. Furthermore, in our model, the lightest supersymmetric particle (LSP) is the axino, that is, the superpartner of the axion. The overabundance of the LSPs due to decays of the modulus/gravitino, which is the most serious cosmological difficulty in the mirage mediation, can be avoided if the axino is sufficiently light. The next-LSPs (NLSPs) produced by the gravitino decay eventually decay into the axino LSPs, yielding the dominant component of the axinos remaining today. It is shown that the axino with a mass of O(100) MeV is naturally realized, which can constitute the dark matter of the Universe, with a free-streaming length of the order of 0.1 Mpc. The saxion, the real scalar component of the axion supermultiplet, can also be cosmologically harmless due to the dilution of the modulus decay. The lifetime of the NLSP is relatively long, but much shorter than 1 sec, when the big-bang nucleosynthesis commences. The decay of the NLSP would provide intriguing collider signatures

  16. Axionic Mirage Mediation

    OpenAIRE

    Nakamura, Shuntaro; Okumura, Ken-ichi; Yamaguchi, Masahiro

    2008-01-01

    In this talk, we propose a model of mirage mediation, in which Peccei-Quinn symmetry is incorporated. In this \\textit{axionic mirage mediation}, it is shown that the Peccei-Quinn symmetry breaking scale is dynamically determined around $10^{10}$ GeV to $10^{12}$ GeV due to the supersymmetry breaking effects. The problems in the original mirage mediation such as the $\\mu$-problem and the moduli problem can be solved simultaneouly. Furthermore, in our model the axino, which is the superpartner ...

  17. DETECTION OF SMALL-SCALE GRANULAR STRUCTURES IN THE QUIET SUN WITH THE NEW SOLAR TELESCOPE

    International Nuclear Information System (INIS)

    Results of a statistical analysis of solar granulation are presented. A data set of 36 images of a quiet-Sun area on the solar disk center was used. The data were obtained with the 1.6 m clear aperture New Solar Telescope at Big Bear Solar Observatory and with a broadband filter centered at the TiO (705.7 nm) spectral line. The very high spatial resolution of the data (diffraction limit of 77 km and pixel scale of 0.''0375) augmented by the very high image contrast (15.5% ± 0.6%) allowed us to detect for the first time a distinct subpopulation of mini-granular structures. These structures are dominant on spatial scales below 600 km. Their size is distributed as a power law with an index of –1.8 (which is close to the Kolmogorov's –5/3 law) and no predominant scale. The regular granules display a Gaussian (normal) size distribution with a mean diameter of 1050 km. Mini-granular structures contribute significantly to the total granular area. They are predominantly confined to the wide dark lanes between regular granules and often form chains and clusters, but different from magnetic bright points. A multi-fractality test reveals that the structures smaller than 600 km represent a multi-fractal, whereas on larger scales the granulation pattern shows no multi-fractality and can be considered as a Gaussian random field. The origin, properties, and role of the population of mini-granular structures in the solar magnetoconvection are yet to be explored.

  18. The Thermal Environment of the Fiber Glass Dome for the New Solar Telescope at Big Bear Solar Observatory

    CERN Document Server

    Verdoni, A P; Varsik, J R; Shumko, S; Nenow, J; Coulter, R

    2007-01-01

    The New Solar Telescope (NST) is a 1.6-meter off-axis Gregory-type telescope with an equatorial mount and an open optical support structure. To mitigate the temperature fluctuations along the exposed optical path, the effects of local/dome-related seeing have to be minimized. To accomplish this, NST will be housed in a 5/8-sphere fiberglass dome that is outfitted with 14 active vents evenly spaced around its perimeter. The 14 vents house louvers that open and close independently of one another to regulate and direct the passage of air through the dome. In January 2006, 16 thermal probes were installed throughout the dome and the temperature distribution was measured. The measurements confirmed the existence of a strong thermal gradient on the order of 5 degree Celsius inside the dome. In December 2006, a second set of temperature measurements were made using different louver configurations. In this study, we present the results of these measurements along with their integration into the thermal control system...

  19. A year of operation of Melibea e-Callisto Solar Radio Telescope

    Science.gov (United States)

    Russu, A.; Gómez-Herrero, R.; Prieto, M.; Monstein, C.; Ivanov, H.; Rodríguez-Pacheco, J.; Blanco, J. J.

    2015-08-01

    The e-CALLISTO (Compound Astronomical Low-cost Low-frequency Instrument for Spectroscopy and Transportable Observatory) is a worldwide radio-spectrograph network with 24 hours a day solar radio burst monitoring. The e-CALLISTO network is led by the Swiss Federal Institute of Technology Zurich (ETHZ Zurich), which work up collaborations with local host institutions. In 2013 the University of Alcalá joined the e-CALLISTO network with the installation of two Solar Radio Telescopes (SRT): the EA4RKU-SRT that was located at the University of Alcalá from January 2013 till June 2013 and the Melibea-SRT that is located at Peralejos de las Truchas (Guadalajara) in operation from June 2013. The Spanish e-Callisto SRTs provide routine data to the network. We present examples of type III and type II radio-bursts observed by Melibea during its first year of operation and study their relation with soft X-ray flares observed by GOES and Coronal Mass Ejections (CMEs) and Solar Energetic Particle (SEP) events observed by space-borne instrumentation.

  20. NEW VACUUM SOLAR TELESCOPE OBSERVATIONS OF A FLUX ROPE TRACKED BY A FILAMENT ACTIVATION

    International Nuclear Information System (INIS)

    One main goal of the New Vacuum Solar Telescope (NVST) which is located at the Fuxian Solar Observatory is to image the Sun at high resolution. Based on the high spatial and temporal resolution NVST Hα data and combined with the simultaneous observations from the Solar Dynamics Observatory for the first time, we investigate a flux rope tracked by filament activation. The filament material is initially located at one end of the flux rope and fills in a section of the rope; the filament is then activated by magnetic field cancellation. The activated filament rises and flows along helical threads, tracking the twisted flux rope structure. The length of the flux rope is about 75 Mm, the average width of its individual threads is 1.11 Mm, and the estimated twist is 1π. The flux rope appears as a dark structure in Hα images, a partial dark and partial bright structure in 304 Å, and as a bright structure in 171 Å and 131 Å images. During this process, the overlying coronal loops are quite steady since the filament is confined within the flux rope and does not erupt successfully. It seems that, for the event in this study, the filament is located and confined within the flux rope threads, instead of being suspended in the dips of twisted magnetic flux

  1. Axionic Mirage Mediation

    CERN Document Server

    Nakamura, Shuntaro; Yamaguchi, Masahiro

    2008-01-01

    Although the mirage mediation is one of the most plausible mediation mechanisms of supersymmetry breaking, it suffers from two crucial problems. One is the \\mu-/B \\mu-problem and the second is the cosmological one. The former stems from the fact that the B parameter tends to be comparable with the gravitino mass, which is two order of magnitude larger than the other soft masses. The latter problem is caused by the decay of the modulus whose branching ratio into the gravitino pair is sizable. In this paper, we propose a model of mirage mediation, in which Peccei-Quinn symmetry is incorporated. In this \\textit{axionic mirage mediation}, it is shown that the PQ symmetry breaking scale is dynamically determined around 10^{10-12} GeV due to the supersymmetry breaking effects, and the \\mu-problem can be solved naturally. Furthermore, in our model, the lightest supersymmetric particle (LSP) is the axino, that is the superpartner of the axion. The overabundance of the LSPs due to decays of modulus/gravitino, which is...

  2. Opto-thermal analysis of a lightweighted mirror for solar telescope

    CERN Document Server

    Banyal, Ravinder K; Chatterjee, S

    2013-01-01

    In this paper, an opto-thermal analysis of a moderately heated lightweighted solar telescope mirror is carried out using 3D finite element analysis (FEA). A physically realistic heat transfer model is developed to account for the radiative heating and energy exchange of the mirror with surroundings. The numerical simulations show the non-uniform temperature distribution and associated thermo-elastic distortions of the mirror blank clearly mimicking the underlying discrete geometry of the lightweighted substrate. The computed mechanical deformation data is analyzed with surface polynomials and the optical quality of the mirror is evaluated with the help of a ray-tracing software. The thermal print-through distortions are further shown to contribute to optical figure changes and mid-spatial frequency errors of the mirror surface. A comparative study presented for three commonly used substrate materials, namely, Zerodur, Pyrex and Silicon Carbide (SiC) is relevant to vast area of large optics requirements in gro...

  3. A Tilt-correction Adaptive Optical System for the Solar Telescope of Nanjing University

    Institute of Scientific and Technical Information of China (English)

    Chang-Hui Rao; Xiu-Fa Gao; Tian Mi; Wen-Han Jiang; Cheng Fang; Ning Ling; Wei-Chao Zhou; Ming-De Ding; Xue-Jun Zhang; Dong-Hong Chen; Mei Li

    2003-01-01

    A tilt-correction adaptive optical system installed on the 430 mm Solar Telescope of Nanjing University has been put in operation. It consists of a tip-tilt mirror, a correlation tracker and an imaging CCD camera. An absolute difference algorithm is used for detecting image motion in the correlation tracker. The sampling frequency of the system is 419 Hz. We give a description of the system's configuration, an analysis of its performance and a report of our observational results. A residual jitter of 0.14 arcsec has been achieved. The error rejection bandwidth of the system can be adjusted in the range 5-28 Hz according to the beacon size and the strength of atmospheric turbulence.

  4. Heat-stop structure design with high cooling efficiency for large ground-based solar telescope.

    Science.gov (United States)

    Liu, Yangyi; Gu, Naiting; Rao, Changhui; Li, Cheng

    2015-07-20

    A heat-stop is one of the most important thermal control devices for a large ground-based solar telescope. For controlling the internal seeing effect, the temperature difference between the heat-stop and the ambient environment needs to be reduced, and a heat-stop with high cooling efficiency is required. In this paper, a novel design concept for the heat-stop, in which a multichannel loop cooling system is utilized to obtain higher cooling efficiency, is proposed. To validate the design, we analyze and compare the cooling efficiency for the multichannel and existing single-channel loop cooling system under the same conditions. Comparative results show that the new design obviously enhances the cooling efficiency of the heat-stop, and the novel design based on the multichannel loop cooling system is obviously better than the existing design by increasing the thermal transfer coefficient. PMID:26367826

  5. Software control of the Advanced Technology Solar Telescope enclosure PLC hardware using COTS software

    Science.gov (United States)

    Borrowman, Alastair J.; de Bilbao, Lander; Ariño, Javier; Murga, Gaizka; Goodrich, Bret; Hubbard, John R.; Greer, Alan; Mayer, Chris; Taylor, Philip

    2012-09-01

    As PLCs evolve from simple logic controllers into more capable Programmable Automation Controllers (PACs), observatories are increasingly using such devices to control complex mechanisms1, 2. This paper describes use of COTS software to control such hardware using the Advanced Technology Solar Telescope (ATST) Common Services Framework (CSF). We present the Enclosure Control System (ECS) under development in Spain and the UK. The paper details selection of the commercial PLC communication library PLCIO. Implemented in C and delivered with source code, the library separates the programmer from communication details through a simple API. Capable of communicating with many types of PLCs (including Allen-Bradley and Siemens) the API remains the same irrespective of PLC in use. The ECS is implemented in Java using the observatory's framework that provides common services for software components. We present a design following a connection-based approach where all components access the PLC through a single connection class. The link between Java and PLCIO C library is provided by a thin Java Native Interface (JNI) layer. Also presented is a software simulator of the PLC based upon the PLCIO Virtual PLC. This creates a simulator operating below the library's API and thus requires no change to ECS software. It also provides enhanced software testing capabilities prior to hardware becoming available. Results are presented in the form of communication timing test data, showing that the use of CSF, JNI and PLCIO provide a control system capable of controlling enclosure tracking mechanisms, that would be equally valid for telescope mount control.

  6. Suppression of Astronomical Sources Using Starshades and the McMath-Pierce Solar Telescope

    Science.gov (United States)

    Novicki, Megan; Warwick, Steve; Smith, Daniel; Richards, Michael; Harness, Anthony

    2016-01-01

    The external starshade is a method for the direct detection and spectral characterization of terrestrial planets around other stars, a key goal identified in ASTRO2010. Tests of this approach have been and continue to be conducted in the lab and in the field (Samuele et al., 2010, Glassman et al., 2014) using non-collimated light sources with a spherical wavefront. We extend the current approach to performing night-time observations of astronomical objects using small-scale (approximately 1/300th) starshades and the McMath-Pierce Solar Telescope at Kitt Peak National Observatory. We placed a starshade directly in the path of the beam from an astronomical object in front of the main heliostat. Using only flat mirrors, we then directed the light through the observatory path and reflected it off the West heliostat to an external telescope located approximately 270m away, for an effective baseline of 420m.This configuration allowed us to make measurements of flat wavefront sources with a Fresnel number close to those expected in proposed full-scale space configurations. We present the results of our engineering runs conducted in 2015.

  7. From axions to other WISPs

    International Nuclear Information System (INIS)

    We illustrate, taking a top-down point of view, how axions and other very weakly interacting sub-eV particles (WISPs) arise in the course of compactification of the extra spatial dimensions in string/M-theory. (orig.)

  8. Eclipses could clarify axion mystery

    CERN Multimedia

    2007-01-01

    "Physicists in Europe have proposed an outlandish experiment that could determine once and for all whether ultralight particles called axions - one of the leading candidates for dark matter - exist." (1/2 page)

  9. FUN with monopoles and axions

    Science.gov (United States)

    Wilczek, F.

    Recent developments in theories of monopoles and axions are summarized, along with several implications. Present day monopoles are relics of early Big Bang processes. The remaining flux may be too small to detect, unless a local enhancement exists, such as a monopole cloud orbiting the sun. The 10 to the 16th GeV inertia of monopoles would require trapping in a magnetic bottle by a specially designed spacecraft. Degenerate monopoles may participate in the strong interactions and may not conserve the baryon number during the interaction. Axions have been postulated as the dynamical theta-field which describes the overall phase of the quark mass matrix. Energy transfer in stars could be accounted for by axions. At high temperatures, such as during the Big Bang, the axion would lose its mass, but in later epochs would be invisible and could account for the missing mass of the universe.

  10. Investigation of intergranular bright points from the New Vacuum Solar Telescope

    Science.gov (United States)

    Ji, Kai-Fan; Xiong, Jian-Ping; Xiang, Yong-Yuan; Feng, Song; Deng, Hui; Wang, Feng; Yang, Yun-Fei

    2016-05-01

    Six high-resolution TiO-band image sequences from the New Vacuum Solar Telescope (NVST) are used to investigate the properties of intergranular bright points (igBPs). We detect the igBPs using a Laplacian and morphological dilation algorithm (LMD) and automatically track them using a three-dimensional segmentation algorithm, and then investigate the morphologic, photometric and dynamic properties of igBPs in terms of equivalent diameter, intensity contrast, lifetime, horizontal velocity, diffusion index, motion range and motion type. The statistical results confirm previous studies based on G-band or TiO-band igBPs from other telescopes. These results illustrate that TiO data from the NVST are stable and reliable, and are suitable for studying igBPs. In addition, our method is feasible for detecting and tracking igBPs with TiO data from the NVST. With the aid of vector magnetograms obtained from the Solar Dynamics Observatory/Helioseismic and Magnetic Imager, the properties of igBPs are found to be strongly influenced by their embedded magnetic environments. The areal coverage, size and intensity contrast values of igBPs are generally larger in regions with higher magnetic flux. However, the dynamics of igBPs, including the horizontal velocity, diffusion index, ratio of motion range and index of motion type are generally larger in the regions with lower magnetic flux. This suggests that the absence of strong magnetic fields in the medium makes it possible for the igBPs to look smaller and weaker, diffuse faster, and move faster and further along a straighter path.

  11. Axions, majorons and neutrino masses

    International Nuclear Information System (INIS)

    We point out that there is an intimate connection between the seesaw scale for the light neutrinos and the invisible axion scale based on a series of recent investigations on the neutrino masses and mixings within a class of realistic SO(10) models. We can then extend the standard model accordingly so that both the standard invisible axion and majoron can be treated in a naturally unified manner. 7 refs

  12. Two applications of axion electrodynamics

    Science.gov (United States)

    Wilczek, Frank

    1987-01-01

    The equations of axion electrodynamics are studied. Variations in the axion field can give rise to peculiar distributions of charge and current. These effects provide a simple understanding of the fractional electric charge on dyons and of some recently discovered oddities in the electrodynamics of antiphase boundaries in PbTe. Some speculations regarding the possible occurrence of related phenomena in other solids are presented.

  13. Thermal analysis of the baffle structure of the Solar Space Telescope

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The SST(Space Solar Telescope) is an astronomical telescope with a primary mirror of 1 m in diameter.It observes the sun with a small view field to ensure that its high spatial resolution imaging has 0.1″-0.15″ and high SNR(signal to noise ratio).Surrounding the small view field is still the sun,which is an intense source of both heat and stray light.The baffles(the main baffle,the aperture,and the outer baffle),which are used to eliminate the stray light,will change the thermal flux in the SST and will weaken the effect of the thermal control design.In this study,the compatibility analysis of the thermal effect of baffle structures in SST is performed.The GCF(Geometry Composing Function) and BRDF(Bidirectional Reflectance Distribution Function),which are two inherent related parameters in the compatibility analysis,are derived.The objective and method of the compatibility analysis are determined.With the thermal analysis software,the temperature fields are calculated for different lengths of the main baffle,different radii of apertures,different lengths of the outer baffle with a 3’ tilt angle and 16’ tilt angle,and different tilt angles of the outer baffle with a 200 mm length.A series of configurations and sizes of the baffles are studied with the goals of both thermal control and elimination of stray light.The design of the baffle structure of SST is achieved:the main baffle of length 4100 mm,the internal shield of radius 494 mm,the outer baffle of length 200 mm,and the outer baffle of tilt angle 3’ are successfully designed.This paper presents the relationship between the thermal control design and stray light elimination plan in the SST.The aims of the optimal design of the baffle structure of SST are reached.The thoughts and methods of the optimal analysis are also useful for similar optical telescopes designed for solar observation.

  14. Detailed design of a resonantly enhanced axion-photon regeneration experiment

    International Nuclear Information System (INIS)

    A resonantly enhanced photon-regeneration experiment to search for the axion or axionlike particles is described. This experiment is a shining light through walls study, where photons traveling through a strong magnetic field are (in part) converted to axions; the axions can pass through an opaque wall and convert (in part) back to photons in a second region of strong magnetic field. The photon regeneration is enhanced by employing matched Fabry-Perot optical cavities, with one cavity within the axion generation magnet and the second within the photon-regeneration magnet. Compared to simple single-pass photon regeneration, this technique would result in a gain of (F/π)2, where F is the finesse of each cavity. This gain could feasibly be as high as 1010, corresponding to an improvement in the sensitivity to the axion-photon coupling, gaγγ, of order (F/π)1/2∼300. This improvement would enable, for the first time, a purely laboratory experiment to probe axion-photon couplings at a level competitive with, or superior to, limits from stellar evolution or solar axion searches. This report gives a detailed discussion of the scheme for actively controlling the two Fabry-Perot cavities and the laser frequencies, and describes the heterodyne signal detection system, with limits ultimately imposed by shot noise.

  15. PET: a proton/electron telescope for studies of magnetospheric, solar, and galactic particles

    International Nuclear Information System (INIS)

    The Proton/Electron Telescope (PET) on SAMPEX is designed to provide measurements of energetic electrons and light nuclei from solar, galactic, and magnetospheric sources. PET is an all solid-state system that will measure the differential energy spectra of electrons from ∼1 to ∼30 MeV and H and He nuclei from ∼20 to ∼300 MeV/nuc, with isotope resolution of H and He extending from ∼20 to ∼80 MeV/nuc. As SAMPEX scans all local times and geomagnetic cutoffs over the course of its near-polar orbit, PET will characterize precipitating relativistic electron events during periods of declining solar activity, and it will examine whether the production rate of odd nitrogen and hydrogen molecules in the middle atmosphere by precipitating electrons is sufficient to affect O3 depletion. In addition, PET will complement studies of the elemental and isotopic composition of energetic heavy (Z > 2) nuclei on SAMPEX by providing measurements of H, He, and electrons. Finally, PET has limited capability to identify energetic positrons from potential natural and man-made sources

  16. Further considerations on layer-oriented adaptive optics for solar telescopes

    CERN Document Server

    Kellerer, Aglae

    2014-01-01

    The future generation of telescopes will be equipped with multi-conjugate adaptive optical (MCAO) systems in order to obtain high angular resolution within large fields of view. MCAO comes in two flavors: star- and layer-oriented. Existing solar MCAO systems rely exclusively on the star-oriented approach. Earlier we have suggested a method to implement the layer-oriented approach, and in view of recent concerns we now explain the proposed scheme in further detail. We note that in any layer-oriented system, one sensor is conjugated to the pupil and the others are conjugated to higher altitudes. For the latter the sensing surface is illuminated by only part of the field-of-view. Nighttime layer-oriented systems correct for this field reduction in terms of the pyramid sensors, which indicate the phase shift directly. Their successful implementation shows that the field reduction is no crucial limitation. In the solar approach the images recorded behind the Shack-Hartmann sub-apertures are vignetted due to the fi...

  17. Backreacted Axion Field Ranges in String Theory

    CERN Document Server

    Baume, Florent

    2016-01-01

    String theory axions are interesting candidates for fields whose potential might be controllable over super-Planckian field ranges and therefore as possible candidates for inflatons in large field inflation. Axion monodromy scenarios are setups where the axion shift symmetry is broken by some effect such that the axion can traverse a large number of periods potentially leading to super-Planckian excursions. We study such scenarios in type IIA string theory where the axion shift symmetry is broken by background fluxes. In particular we calculate the backreaction of the energy density induced by the axion vacuum expectation value on its own field space metric. We find universal behaviour for all the compactifications studied where up to a certain critical axion value there is only a small backreaction effect. Beyond the critical value the backreaction is strong and implies that the proper field distance as measured by the backreacted metric increases at best logarithmically with the axion vev, thereby placing s...

  18. Axion: Mass -- Dark Matter Abundance Relation

    CERN Document Server

    CERN. Geneva

    2016-01-01

    The axion is a hypothetical particle which would explain why QCD is approximately T-conserving, and is also an excellent Cold Dark Matter candidate. It should be possible to make a clean theoretical prediction relating the dark matter density in axions and the axion mass (under reasonable assumptions about inflation). But the axion's early-Universe dynamics, which establish its density as dark matter, are unexpectedly rich in a way which is only starting to yield to quantitative numerical study.

  19. Is the invisible hadronic axion always harmless

    International Nuclear Information System (INIS)

    In the Dine-Fischler-Srednicki-Zhitnitsky (DFSZ) axion model, if the invisible axion is hadronized (i.e. if the axion is made to decouple from leptons at tree level), it will be accompanied by a visible real Goldstone boson which interacts with both leptons and quarks. Consequently, the Higgs field coupled to right-handed leptons must also couple to right-handed d- or μ-type quark singlets. Astrophysical bounds on viable hadronic axions are discussed

  20. Experimental Searches for the Axion and Axion-like Particles

    CERN Document Server

    Graham, Peter W; Lamoreaux, Steven K; Lindner, Axel; van Bibber, Karl A

    2016-01-01

    Four decades after its prediction, the axion remains the most compelling solution to the Strong-CP problem and a well-motivated dark matter candidate, inspiring a host of elegant and ultrasensitive experiments based on axion-photon mixing. This report reviews the experimental situation on several fronts. The microwave cavity experiment is making excellent progress in the search for dark matter axions in the microelectronvolt range and may be plausibly extended up to 100 mu eV. Within the past several years however, it has been realized that axions are pervasive throughout string theories, but with masses that fall naturally in the nanoelectronvolt range, for which a NMR-based search is under development. Searches for axions emitted from the Sun's burning core, and purely laboratory experiments based on photon regeneration have both made great strides in recent years, with ambitious projects proposed for the coming decade. Each of these campaigns has pushed the state of the art in technology, enabling large ga...

  1. Interaction of axions with relativistic spinning particles

    Science.gov (United States)

    Popov, V. A.; Balakin, A. B.

    2016-05-01

    We consider a covariant phenomenological model, which describes an interaction between a pseudoscalar (axion) field and massive spinning particles. The model extends the Bagrmann-Michel-Telegdy approach in application to the axion electrodynamics. We present some exact solutions and discuss them in the context of experimental tests of the model and axion detection.

  2. Active galaxies can make axionic dark energy

    OpenAIRE

    Dimopoulos, Konstantinos; Cormack, Sam

    2016-01-01

    AGN jets carry helical magnetic fields, which can affect dark matter if the latter is axionic. This preliminary study shows that, in the presence of strong helical magnetic fields, the nature of the axionic condensate may change and become dark energy. Such dark energy may affect galaxy formation and galactic dynamics, so this possibility should not be ignored when considering axionic dark matter.

  3. Interaction of axions with relativistic spinning particles

    CERN Document Server

    Popov, V A

    2016-01-01

    We consider a covariant phenomenological model, which describes an interaction between a pseudoscalar (axion) field and massive spinning particles. The model extends the Bagrmann-Michel-Telegdy approach in application to the axion electrodynamics. We present some exact solutions and discuss them in the context of experimental tests of the model and axion detection.

  4. Ultra-Narrow Negative Flare Front Observed in Helium-10830 Å Using the1.6m New Solar Telescope

    Science.gov (United States)

    Xu, Yan; Cao, Wenda; Ding, Mingde; Kleint, Lucia; Su, Jiangtao; Liu, Chang; Ji, Haisheng; Chae, Jongchul; Jing, Ju; Cho, Kyuhyoun; Cho, Kyung-Suk; Gary, Dale E.; Wang, Haimin

    2016-05-01

    Solar flares are sudden flashes of brightness on the Sun and are often associated with coronal mass ejections and solar energetic particles that have adverse effects on the near-Earth environment. By definition, flares are usually referred to as bright features resulting from excess emission. Using the newly commissioned 1.6-m New Solar Telescope at Big Bear Solar Observatory, we show a striking “negative” flare with a narrow but unambiguous “dark” moving front observed in He I 10830 Å, which is as narrow as 340 km and is associated with distinct spectral characteristics in Hα and Mg II lines. Theoretically, such negative contrast in He I 10830 Å can be produced under special circumstances by nonthermal electron collisions or photoionization followed by recombination. Our discovery, made possible due to unprecedented spatial resolution, confirms the presence of the required plasma conditions and provides unique information in understanding the energy release and radiative transfer in solar flares.

  5. Axion Decay and Anisotropy of Near-IR Extragalactic Background Light

    Science.gov (United States)

    Gong, Yan; Cooray, Asantha; Mitchell-Wynne, Ketron; Chen, Xuelei; Zemcov, Michael; Smidt, Joseph

    2016-07-01

    The extragalactic background light (EBL) is composed of the cumulative radiation from all galaxies and active galactic nuclei over cosmic history. In addition to point sources, the EBL also contains information from diffuse sources of radiation. The angular power spectra of the near-infrared intensities could contain additional signals, and a complete understanding of the nature of the infrared (IR) background is still lacking in the literature. Here we explore the constraints that can be placed on particle decays, especially candidate dark matter (DM) models involving axions that trace DM halos of galaxies. Axions with a mass around a few electronvolts will decay via two photons with wavelengths in the near-IR band and will leave a signature in the IR background intensity power spectrum. Using recent power spectra measurements from the Hubble Space Telescope and the Cosmic Infrared Background Experiment, we find that the 0.6–1.6 μm power spectra can be explained by axions with masses around 4 eV. The total axion abundance Ω a ≃ 0.05, and it is comparable to the baryon density of the universe. The suggested mean axion mass and abundance are not ruled out by existing cosmological observations. Interestingly, the axion model with a mass distribution is preferred by the data, which cannot be explained by the standard quantum chromodynamics theory and needs further discussion.

  6. Development of a Lyman-α Imaging Solar Telescope for the Satellite

    Science.gov (United States)

    Jang, M.; Oh, H.-S.; Rim, C.-S.; Park, J.-S.; Kim, J.-S.; Son, D.

    2005-09-01

    Long term observations of full-disk Lyman-α irradiance have been made by the instruments on various satellites. In addition, several sounding rockets dating back to the 1950s and up through the present have measured the Lyman-α irradiance. Previous full disk Lyman-α images of the sun have been very interesting and useful scientifically, but have been only five-minute ``snapshots" obtained on sounding rocket flights. All of these observations to date have been snapshots, with no time resolution to observe changes in the chromospheric structure as a result of the evolving magnetic field, and its effect on the Lyman-α intensity. The Lyman-α Imaging Solar Telescope(LIST) can provide a unique opportunity for the study of the sun in the Lyman-α region with the high time and spatial resolution for the first time. Up to the 2nd year development, the preliminary design of the optics, mechanical structure and electronics system has been completed. Also the mechanical structure analysis, thermal analysis were performed and the material for the structure was chosen as a result of these analyses. And the test plan and the verification matrix were decided. The operation systems, technical and scientific operation, were studied and finally decided. Those are the technical operation, mechanical working modes for the observation and safety, the scientific operation and the process of the acquired data. The basic techniques acquired through the development of satellite based solar telescope are essential for the construction of space environment forecast system in the future. The techniques which we developed through this study, like mechanical, optical and data processing techniques, could be applied extensively not only to the process of the future production of flight models of this kind, but also to the related industries. Also, we can utilize the scientific achievements which are obtained throughout the project. And these can be utilized to build a high resolution

  7. Axion landscape and natural inflation

    International Nuclear Information System (INIS)

    Multiple axions form a landscape in the presence of various shift symmetry breaking terms. Eternal inflation populates the axion landscape, continuously creating new universes by bubble nucleation. Slow-roll inflation takes place after the tunneling event, if a very flat direction with a super-Planckian decay constant arises due to the alignment mechanism. We study the vacuum structure as well as possible inflationary dynamics in the axion landscape scenario, and find that the inflaton dynamics is given by either natural or multi-natural inflation. In the limit of large decay constant, it is approximated by the quadratic chaotic inflation, which however is disfavored if there is a pressure toward shorter duration of inflation. Therefore, if the spectral index and the tensor-to-scalar ratio turn out to be different from the quadratic chaotic inflation, there might be observable traces of the bubble nucleation. Also, the existence of small modulations to the inflaton potential is a common feature in the axion landscape, which generates a sizable and almost constant running of the scalar spectral index over CMB scales. Non-Gaussianity of equilateral type can also be generated if some of the axions are coupled to massless gauge fields

  8. The axion mass in modular invariant supergravity

    International Nuclear Information System (INIS)

    When supersymmetry is broken by condensates with a single condensing gauge group, there is a nonanomalous R-symmetry that prevents the universal axion from acquiring a mass. It has been argued that, in the context of supergravity, higher dimension operators will break this symmetry and may generate an axion mass too large to allow the identification of the universal axion with the QCD axion. We show that such contributions to the axion mass are highly suppressed in a class of models where the effective Lagrangian for gaugino and matter condensation respects modular invariance (T-duality)

  9. Theory of Light Scattering in Axion Electrodynamics

    Science.gov (United States)

    Ochiai, Tetsuyuki

    2012-09-01

    Taking account of the axion term in the Maxwell Lagrangian, we present a rigorous theory of light scattering in piecewise-constant axion fields. In particular, we focus on axionic substances with confined and/or curved geometries, and the scattering matrices of an axionic slab, cylinder, and sphere are derived analytically. The axion term generates a surface current with off-diagonal optical conductivity, giving rise to a new type of photospin--orbit interaction. As a result, various novel light-scattering phenomena can take place. We demonstrate enhanced Faraday rotation, parity-violating light scattering, and strong perturbation of dipole radiation.

  10. DYNAMICS IN SUNSPOT UMBRA AS SEEN IN NEW SOLAR TELESCOPE AND INTERFACE REGION IMAGING SPECTROGRAPH DATA

    Energy Technology Data Exchange (ETDEWEB)

    Yurchyshyn, V.; Abramenko, V. [Big Bear Solar Observatory, New Jersey Institute of Technology, Big Bear City, CA 92314 (United States); Kilcik, A. [Department of Space Science and Technologies, Akdeniz University, 07058 Antalya (Turkey)

    2015-01-10

    We analyze sunspot oscillations using Interface Region Imaging Spectrograph (IRIS) slit-jaw and spectral data and narrow-band chromospheric images from the New Solar Telescope (NST) for the main sunspot in NOAA AR 11836. We report that the difference between the shock arrival times as measured by the Mg II k 2796.35 Å and Si IV 1393.76 Å line formation levels changes during the observed period, and peak-to-peak delays may range from 40 s to zero. The intensity of chromospheric shocks also displays long-term (about 20 min) variations. NST's high spatial resolution Hα data allowed us to conclude that, in this sunspot, umbral flashes (UFs) appeared in the form of narrow bright lanes stretched along the light bridges and around clusters of umbral bright points. The time series also suggested that UFs preferred to appear on the sunspot-center side of light bridges, which may indicate the existence of a compact sub-photospheric driver of sunspot oscillations. The sunspot's umbra as seen in the IRIS chromospheric and transition region data appears bright above the locations of light bridges and the areas where the dark umbra is dotted with clusters of umbral dots. Co-spatial and co-temporal data from the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory showed that the same locations were associated with bright footpoints of coronal loops suggesting that the light bridges may play an important role in heating the coronal sunspot loops. Finally, the power spectra analysis showed that the intensity of chromospheric and transition region oscillations significantly vary across the umbra and with height, suggesting that umbral non-uniformities and the structure of sunspot magnetic fields may play a role in wave propagation and heating of umbral loops.

  11. DYNAMICS IN SUNSPOT UMBRA AS SEEN IN NEW SOLAR TELESCOPE AND INTERFACE REGION IMAGING SPECTROGRAPH DATA

    International Nuclear Information System (INIS)

    We analyze sunspot oscillations using Interface Region Imaging Spectrograph (IRIS) slit-jaw and spectral data and narrow-band chromospheric images from the New Solar Telescope (NST) for the main sunspot in NOAA AR 11836. We report that the difference between the shock arrival times as measured by the Mg II k 2796.35 Å and Si IV 1393.76 Å line formation levels changes during the observed period, and peak-to-peak delays may range from 40 s to zero. The intensity of chromospheric shocks also displays long-term (about 20 min) variations. NST's high spatial resolution Hα data allowed us to conclude that, in this sunspot, umbral flashes (UFs) appeared in the form of narrow bright lanes stretched along the light bridges and around clusters of umbral bright points. The time series also suggested that UFs preferred to appear on the sunspot-center side of light bridges, which may indicate the existence of a compact sub-photospheric driver of sunspot oscillations. The sunspot's umbra as seen in the IRIS chromospheric and transition region data appears bright above the locations of light bridges and the areas where the dark umbra is dotted with clusters of umbral dots. Co-spatial and co-temporal data from the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory showed that the same locations were associated with bright footpoints of coronal loops suggesting that the light bridges may play an important role in heating the coronal sunspot loops. Finally, the power spectra analysis showed that the intensity of chromospheric and transition region oscillations significantly vary across the umbra and with height, suggesting that umbral non-uniformities and the structure of sunspot magnetic fields may play a role in wave propagation and heating of umbral loops

  12. The Swedish Vacuum Solar Telescope data-acquisition and control systems

    Science.gov (United States)

    Shand, Mark; Scharmer, Göran B.

    1998-11-01

    The performance of commodity computer systems doubles approximately every 18 months. Traditionally, the design of scientific data-acquisition and control systems has tended to ignore this fact, relying instead on custom hardware developments using the technology available at the time of instrument specification. Moreover, development manpower is usually limited, causing relatively long development cycles. Often the the result is that an instrument is technologically obsolete quite early in its projected lifetime. In contrast, all the digital processing for data acquisition and control at the Swedish Vacuum Solar Telescope (SVST) on La Palma (Canary Islands) is performed with commodity workstations. The result is a flexible system with low development costs that can easily take advantage of the latest microprocessor advances. The SVST's use of commodity workstations in on-line real-time tasks is in large part made possible by its use of reconfigurable interface technology. Indeed the SVST has been a valuable proving ground for this technology. This article summarizes the instrumentation of the SVST and illustrates examples of data recorded with this instrumentation.

  13. Dynamics in Sunspot Umbra as Seen in New Solar Telescope and Interface Region Imaging Spectrograph Data

    CERN Document Server

    Yurchyshyn, Vasyl; Kilcik, Ali

    2014-01-01

    We analyse sunspot oscillations using Interface Region Imaging Spectrograph (IRIS) slit-jaw and spectral data and narrow-band chromospheric images from the New Solar Telescope (NST) for the main sunspot in NOAA AR 11836. We report that the difference between the shock arrival times as measured the Mg II k 2796.35\\AA\\ and Si IV 1393.76\\AA\\ line formation levels changes during the observed period and peak-to-peak delays may range from 40~s to zero. The intensity of chromospheric shocks also displays a long term (about 20~min) variations. NST's high spatial resolution \\ha\\ data allowed us to conclude that in this sunspot umbral flashes (UFs) appeared in the form of narrow bright lanes stretched along the light bridges and around clusters of umbral bright points. Time series also suggested that UFs preferred to appear on the sunspot-center side of light bridges, which may indicate the existence of a compact sub-photospheric driver of sunspot oscillations. The sunspot's umbra as seen in the IRIS chromospheric and ...

  14. MAGNETIC RECONNECTION BETWEEN SMALL-SCALE LOOPS OBSERVED WITH THE NEW VACUUM SOLAR TELESCOPE

    International Nuclear Information System (INIS)

    Using the high tempo-spatial resolution Hα images observed with the New Vacuum Solar Telescope, we report solid observational evidence of magnetic reconnection between two sets of small-scale, anti-parallel loops with an X-shaped topology. The reconnection process contains two steps: a slow step with a duration of more than several tens of minutes, and a rapid step lasting for only about three minutes. During the slow reconnection, two sets of anti-parallel loops gradually reconnect, and new loops are formed and stacked together. During the rapid reconnection, the anti-parallel loops approach each other quickly, and then rapid reconnection takes place, resulting in the disappearance of the former loops. In the meantime, new loops are formed and separate. The region between the approaching loops is brightened, and the thickness and length of this region are determined to be about 420 km and 1.4 Mm, respectively. During the rapid reconnection process, obvious brightenings at the reconnection site and apparent material ejections outward along reconnected loops are observed. These observed signatures are consistent with predictions by reconnection models. We suggest that the successive slow reconnection changes the conditions around the reconnection site and triggers instabilities, thus leading to the rapid approach of the anti-parallel loops and resulting in the rapid reconnection

  15. Opto-thermal analysis of a lightweighted mirror for solar telescope.

    Science.gov (United States)

    Banyal, Ravinder K; Ravindra, B; Chatterjee, S

    2013-03-25

    In this paper, an opto-thermal analysis of a moderately heated lightweighted solar telescope mirror is carried out using 3D finite element analysis (FEA). A physically realistic heat transfer model is developed to account for the radiative heating and energy exchange of the mirror with surroundings. The numerical simulations show the non-uniform temperature distribution and associated thermo-elastic distortions of the mirror blank clearly mimicking the underlying discrete geometry of the lightweighted substrate. The computed mechanical deformation data is analyzed with surface polynomials and the optical quality of the mirror is evaluated with the help of a ray-tracing software. The thermal print-through distortions are further shown to contribute to optical figure changes and mid-spatial frequency errors of the mirror surface. A comparative study presented for three commonly used substrate materials, namely, Zerodur, Pyrex and Silicon Carbide (SiC) is relevant to vast area of large optics requirements in ground and space applications. PMID:23546089

  16. Plate coil thermal test bench for the Daniel K. Inouye Solar Telescope (DKIST) carousel cooling system

    Science.gov (United States)

    Phelps, LeEllen; Murga, Gaizka; Montijo, Guillermo; Hauth, David

    2014-08-01

    Analyses have shown that even a white-painted enclosure requires active exterior skin-cooling systems to mitigate dome seeing which is driven by thermal nonuniformities that change the refractive index of the air. For the Daniel K. Inouye Solar Telescope (DKIST) Enclosure, this active surface temperature control will take the form of a system of water cooled plate coils integrated into the enclosure cladding system. The main objective of this system is to maintain the surface temperature of the enclosure as close as possible to, but always below, local ambient temperature in order to mitigate this effect. The results of analyses using a multi-layer cladding temperature model were applied to predict the behavior of the plate coil cladding system and ultimately, with safety margins incorporated into the resulting design thermal loads, the detailed designs. Construction drawings and specifications have been produced. Based on these designs and prior to procurement of the system components, a test system was constructed in order to measure actual system behavior. The data collected during seasonal test runs at the DKIST construction site on Haleakalā are used to validate and/or refine the design models and construction documents as appropriate. The test fixture was also used to compare competing hardware, software, components, control strategies, and configurations. This paper outlines the design, construction, test protocols, and results obtained of the plate coil thermal test bench for the DKIST carousel cooling system.

  17. Axion dark matter: strings and their cores

    Energy Technology Data Exchange (ETDEWEB)

    Fleury, Leesa [McGill University, Department of Physics,3600 rue University, Montréal QC H3A 2T8 (Canada); Moore, Guy D. [Institut für Kernphysik, Technische Universität Darmstadt,Schlossgartenstraße 2, D-64289 Darmstadt (Germany)

    2016-01-04

    Axions constitute a well-motivated dark matter candidate, and if PQ symmetry breaking occurred after inflation, it should be possible to make a clean prediction for the relation between the axion mass and the axion dark matter density. We show that axion (or other global) string networks in 3D have a network density that depends logarithmically on the string separation-to-core ratio. This logarithm would be about 10 times larger in axion cosmology than what we can achieve in numerical simulations. We simulate axion production in the early Universe, finding that, for the separation-to-core ratios we can achieve, the changing density of the network has little impact on the axion production efficiency.

  18. Ultra-narrow Negative Flare Front Observed in Helium-10830~\\AA\\ using the 1.6 m New Solar Telescope

    CERN Document Server

    Xu, Yan; Ding, Mingde; Kleint, Lucia; Su, Jiangtao; Liu, Chang; Ji, Haisheng; Chae, Jongchul; Jing, Ju; Cho, Kyuhyoun; Cho, Kyungsuk; Gary, Dale; Wang, Haimin

    2016-01-01

    Solar flares are sudden flashes of brightness on the Sun and are often associated with coronal mass ejections and solar energetic particles which have adverse effects in the near Earth environment. By definition, flares are usually referred to bright features resulting from excess emission. Using the newly commissioned 1.6~m New Solar Telescope at Big Bear Solar Observatory, here we show a striking "negative" flare with a narrow, but unambiguous "dark" moving front observed in He I 10830 \\AA, which is as narrow as 340 km and is associated with distinct spectral characteristics in H-alpha and Mg II lines. Theoretically, such negative contrast in He I 10830 \\AA\\ can be produced under special circumstances, by nonthermal-electron collisions, or photoionization followed by recombination. Our discovery, made possible due to unprecedented spatial resolution, confirms the presence of the required plasma conditions and provides unique information in understanding the energy release and radiative transfer in astronomi...

  19. Backreacted axion field ranges in string theory

    Science.gov (United States)

    Baume, Florent; Palti, Eran

    2016-08-01

    String theory axions are interesting candidates for fields whose potential might be controllable over super-Planckian field ranges and therefore as possible candidates for inflatons in large field inflation. Axion monodromy scenarios are setups where the axion shift symmetry is broken by some effect such that the axion can traverse a large number of periods potentially leading to super-Planckian excursions. We study such scenarios in type IIA string theory where the axion shift symmetry is broken by background fluxes. In particular we calculate the backreaction of the energy density induced by the axion vacuum expectation value on its own field space metric. We find universal behaviour for all the compactifications studied where up to a certain critical axion value there is only a small backreaction effect. Beyond the critical value the backreaction is strong and implies that the proper field distance as measured by the backreacted metric increases at best logarithmically with the axion vev, thereby placing strong limitations on extending the field distance any further. The critical axion value can be made arbitrarily large by the choice of fluxes. However the backreaction of these fluxes on the axion field space metric ensures a precise cancellation such that the proper field distance up to the critical axion value is flux independent and remains sub-Planckian. We also study an axion alignment scenario for type IIA compactifications on a twisted torus with four fundamental axions mixing to leave an axion with an effective decay constant which is flux dependent. There is a choice of fluxes for which the alignment parameter controlling the effective decay constant is unconstrained by tadpoles and can in principle lead to an arbitrarily large effective decay constant. However we show that these fluxes backreact on the fundamental decay constants so as to precisely cancel any enhancement leaving a sub-Planckian effective decay constant.

  20. Production of the 4.26 m ZERODUR mirror blank for the Advanced Technology Solar telescope (ATST)

    Science.gov (United States)

    Jedamzik, Ralf; Werner, Thomas; Westerhoff, Thomas

    2014-07-01

    The Daniel K. Inouye Solar Telescope (DKIST, formerly the Advanced Technology Solar Telescope, ATST) will be the most powerful solar telescope in the world. It is currently being built by the Association of Universities for Research in Astronomy (AURA) in a height of 3000 m above sea level on the mountain Haleakala of Maui, Hawaii. The primary mirror blank of diameter 4.26 m is made of the extremely low thermal expansion glass ceramic ZERODUR® of SCHOTT AG Advanced Optics. The DKIST primary mirror design is extremely challenging. With a mirror thickness of only 78 to 85 mm it is the smallest thickness ever machined on a mirror of 4.26 m in diameter. Additionally the glassy ZERODUR® casting is one of the largest in size ever produced for a 4 m class ZERODUR® mirror blank. The off axis aspherical mirror surface required sophisticated grinding procedures to achieve the specified geometrical tolerance. The small thickness of about 80 mm required special measures during processing, lifting and transport. Additionally acid etch treatment was applied to the convex back-surface and the conical shaped outer diameter surface to improve the strength of the blank. This paper reports on the challenging tasks and the achievements on the material property and dimensional specification parameter during the production of the 4.26 m ZERODUR® primary mirror blank for AURA.

  1. Axion-Assisted Electroweak Baryogenesis

    CERN Document Server

    Craig, Nathaniel

    2010-01-01

    We consider a hidden-valley gauge sector, G, with strong coupling scale Lambda~TeV and CP-violating topological parameter, theta, as well as a new axion degree of freedom which adjusts theta to near zero in the current universe. If the G-sector couples to the Standard Model via weak-scale states charged under both, then in the early universe it is possible for the CP-violation due to theta (which has not yet been adjusted to zero by the hidden axion) to feed in to the SM and drive efficient baryogenesis during the electroweak (EW) phase transition, independent of the effectively small amount of CP violation present in the SM itself. While current constraints on both the new axion and charged states are easily satisfied, we argue that the LHC can investigate the vast majority of parameter space where EW-baryogenesis is efficiently assisted, while the hidden axion should comprise a significant fraction of the dark matter density. In the supersymmetric version, the ``messenger'' matter communicating between the ...

  2. Axion overview and the U.S. RF cavity axion search

    Energy Technology Data Exchange (ETDEWEB)

    Rosenberg, L.J. [Massachusetts Inst. of Tech., Cambridge, MA (United States); van Bibber, K.A.

    1998-01-01

    The axion, a hypothetical elementary particle, originally emerged from a solution to the strong CP problem in QCD. Later, axions were recognized as good dark matter candidates. Dark matter axions have only feeble couplings to matter and radiation, so their detection offers considerable challenge. Nonetheless, a new generation of exquisitely sensitive searches is underway. One such effort, in the United States, has already achieved sensitivity to plausible halo dark matter axion to photon couplings.

  3. Flows in and around active region NOAA12118 observed with the GREGOR solar telescope and SDO/HMI

    CERN Document Server

    Verma, M; Balthasar, H; Kuckein, C; Manrique, S J González; Sobotka, M; González, N Bello; Hoch, S; Diercke, A; Kummerow, P; Berkefeld, T; Collados, M; Feller, A; Hofmann, A; Kneer, F; Lagg, A; Löhner-Böttcher, J; Nicklas, H; Yabar, A Pastor; Schlichenmaier, R; Schmidt, D; Schmidt, W; Schubert, M; Sigwarth, M; Solanki, S K; Soltau, D; Staude, J; Strassmeier, K G; Volkmer, R; von der Lühe, O; Waldmann, T

    2016-01-01

    Accurate measurements of magnetic and velocity fields in and around solar active regions are key to unlocking the mysteries of the formation and the decay of sunspots. High spatial resolution image and spectral sequences with a high cadence obtained with the GREGOR solar telescope give us an opportunity to scrutinize 3-D flow fields with local correlation tracking and imaging spectroscopy. We present GREGOR early science data acquired in 2014 July - August with the GREGOR Fabry-P\\'erot Interferometer and the Blue Imaging Channel. Time-series of blue continuum (? 450.6 nm) images of the small active region NOAA 12118 were restored with the speckle masking technique to derive horizontal proper motions and to track the evolution of morphological changes. In addition, high-resolution observations are discussed in the context of synoptic data from the Solar Dynamics Observatory.

  4. The spectrometer telescope for imaging x-rays on board the Solar Orbiter mission

    Czech Academy of Sciences Publication Activity Database

    Benz, A. O.; Krucker, S.; Hurford, G.J.; Arnold, N.G.; Orleanski, P.; Gröbelbauer, H.-P.; Klober, S.; Iseli, L.; Wiehl, H.J.; Csillaghy, A.; Fárník, František; Kašparová, Jana

    Bellingham : International Society for Optical Engineering, 2012, 84433L-1-84433L-15. ISBN 9780819491442. - (Proceedings of SPIE. 8443). [Space Telescopes and Instrumentation 2012: Ultraviolet to Gamma Ray. Amsterdam (NL), 01.07.2012-06.07.2012] Institutional support: RVO:67985815 Keywords : telescopes * imaging spectroscopy * pectrometers Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  5. Simulated Solar Flare X-Ray and Thermal Cycling Durability Evaluation of Hubble Space Telescope Thermal Control Candidate Replacement Materials

    Science.gov (United States)

    deGroh, Kim K.; Banks, Bruce A.; Sechkar, Edward A.; Scheiman, David A.

    1998-01-01

    During the Hubble Space Telescope (HST) second servicing mission (SM2), astronauts noticed that the multilayer insulation (MLI) covering the telescope was damaged. Large pieces of the outer layer of MLI (aluminized Teflon fluorinated ethylene propylene (Al-FEP)) were torn in several locations around the telescope. A piece of curled up Al-FEP was retrieved by the astronauts and was found to be severely embrittled, as witnessed by ground testing. Goddard Space Flight Center (GSFC) organized a HST MLI Failure Review Board (FRB) to determine the damage mechanism of FEP in the HST environment, and to recommend replacement insulation material to be installed on HST during the third servicing mission (SM3) in 1999. Candidate thermal control replacement materials were chosen by the FRB and tested for environmental durability under various exposures and durations. This paper describes durability testing of candidate materials which were exposed to charged particle radiation, simulated solar flare x-ray radiation and thermal cycling under load. Samples were evaluated for changes in solar absorptance and tear resistance. Descriptions of environmental exposures and durability evaluations of these materials are presented.

  6. Searching for Dark-Matter Axions

    Science.gov (United States)

    Rosenberg, Leslie

    2016-03-01

    The axion is a hypothetical elementary particle arising in the 1970's from an elegant solution to the Strong CP problem in Quantum Chromo Dynamics. Light QCD axions (masses technology has advanced to where such axions might be detected. Several large searches are in the construction and commissioning phase, with new projects in the development phase. There are also concepts for new detector technologies aimed at improving the sensitivity and axion mass-reach. These searches would have the potential to detect even the more pessimistically-coupled dark-matter axions should they contribute a fraction of the local Milky Way dark-matter halo. This talk discusses the dark-matter axion experimental landscape and the prospects for their discovery. Supported by the U.S. Department of Energy, Office of High Energy Physics.

  7. On supersymmetric effective theories of axion

    Energy Technology Data Exchange (ETDEWEB)

    Higaki, Tetsutaro [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Kitano, Ryuichiro [Tohoku Univ., Sendai (Japan). Dept. of Physics

    2011-04-15

    We study effective theories of an axion in spontaneously broken supersymmetric theories. We consider a system where the axion supermultiplet is directly coupled to a supersymmetry breaking sector whereas the standard model sector is communicated with those sectors through loops of messenger fields. The gaugino masses and the axion-gluon coupling necessary for solving the strong CP problem are both obtained by the same effective interaction. We discuss cosmological constraints on this framework. (orig.)

  8. Dynamical Axion Field in Topological Magnetic Insulators

    OpenAIRE

    Li, Rundong; Jing WANG; Qi, Xiaoliang; Zhang, Shou-Cheng

    2009-01-01

    Axions are very light, very weakly interacting particles postulated more than 30 years ago in the context of the Standard Model of particle physics. Their existence could explain the missing dark matter of the universe. However, despite intensive searches, they have yet to be detected. In this work, we show that magnetic fluctuations of topological insulators couple to the electromagnetic fields exactly like the axions, and propose several experiments to detect this dynamical axion field. In ...

  9. On supersymmetric effective theories of axion

    International Nuclear Information System (INIS)

    We study effective theories of an axion in spontaneously broken supersymmetric theories. We consider a system where the axion supermultiplet is directly coupled to a supersymmetry breaking sector whereas the standard model sector is communicated with those sectors through loops of messenger fields. The gaugino masses and the axion-gluon coupling necessary for solving the strong CP problem are both obtained by the same effective interaction. We discuss cosmological constraints on this framework. (orig.)

  10. Advancement of Piezo-Stack DM technology at CILAS: Example of HODM for KIS Gregor Solar Telescope

    Science.gov (United States)

    Sinquin, J. C.; Bastard, A.; Cousty, R.; Guillemard, C.; Pagès, H.

    2011-09-01

    Cilas has designed, manufactured and tested the deformable mirror for use in the high order adaptive optics system in the 1.5 m Gregor solar telescope (Tenerife). In the scope of this project for Kiepenheuer-Institut für Sonnenphysik (KIS), we have reached the smallest spacing ever made with our piezo-stack technology (3.2 mm) while increasing the overall reliability of our DMs by significant design evolutions. We will present the main specifications of the DM (18x18 actuator array, > 2 μm interactuator stroke, > 20 kHz main resonance frequency) and the study results on reliability. This study is focused on electrical and opto-mechanical stability of the DM vs. time. The improved piezo-stack technology will be used for next generation of DMs for large telescopes as TMT and ESO (VLT and E-ELT)

  11. Detection of zero anisotropy at 5.2 AU during the November 1998 solar particle event: Ulysses Anisotropy Telescopes observations

    Directory of Open Access Journals (Sweden)

    S. Dalla

    Full Text Available For the first time during the mission, the Anisotropy Telescopes instrument on board the Ulysses spacecraft measured constant zero anisotropy of protons in the 1.3-2.2 MeV energy range, for a period lasting more than three days. This measurement was made during the energetic particle event taking place at Ulysses between 25 November and 15 December 1998, an event characterised by constant high proton fluxes within a region delimited by two interplanetary forward shocks, at a distance of 5.2 AU from the Sun and heliographic latitude of 17°S. We present the ATs results for this event and discuss their possible interpretation and their relevance to the issue of intercalibration of the two telescopes.

    Key words: Interplanetary physics (energetic particles - Solar physics, astrophysics and astronomy (energetic particles - Space plasma physics (instruments and techniques

  12. Axion Dark Matter Detection with Cold Molecules

    OpenAIRE

    Graham, Peter W.; Rajendran, Surjeet

    2011-01-01

    Current techniques cannot detect axion dark matter over much of its parameter space, particularly in the theoretically well-motivated region where the axion decay constant f_a lies near the GUT and Planck scales. We suggest a novel experimental method to search for QCD axion dark matter in this region. The axion field oscillates at a frequency equal to its mass when it is a component of dark matter. These oscillations induce time varying CP-odd nuclear moments, such as electric dipole and Sch...

  13. Axion induced oscillating electric dipole moments

    Energy Technology Data Exchange (ETDEWEB)

    Hill, Christopher T. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2015-06-24

    In this study, the axion electromagnetic anomaly induces an oscillating electric dipole for any magnetic dipole. This is a low energy theorem which is a consequence of the space-time dependent cosmic background field of the axion. The electron will acquire an oscillating electric dipole of frequency ma and strength ~ 10-32 e-cm, within four orders of magnitude of the present standard model DC limit, and two orders of magnitude above the nucleon, assuming standard axion model and dark matter parameters. This may suggest sensitive new experimental venues for the axion dark matter search.

  14. Fast Radio Bursts from Axion Stars

    CERN Document Server

    Iwazaki, Aiichi

    2014-01-01

    Axions are one of the most promising candidates of dark matter. The axions have been shown to form miniclusters with masses $\\sim 10^{-12}M_{\\odot}$ and to become dominant component of dark matter. These axion miniclusters condense to form axion stars. We show a possible origin of fast radio bursts ( FRBs ) by assuming the axion stars being dark matter: FRBs arise from the collisions between the axion stars and neutron stars. The FRBs are caused by the rapid conversion of the axions into electromagnetic fields under strong magnetic fields. Electric fields are induced on the axion stars under strong magnetic fields of neutron stars. The electric fields parallel to the magnetic fields oscillate with a frequency and make electrons in atmospheres of neutron stars coherently oscillate. Thus, the coherent radiations are emitted. The observed frequencies ( $\\sim 1.4$GHz ) of the bursts are given by the axion mass $m_a$ such as $m_a/2\\pi\\simeq 2.3\\,\\mbox{GHz}\\,\\big(m_a/10^{-5}\\mbox{eV}\\big)$. The frequency is affecte...

  15. R-axion detection at LHC

    Energy Technology Data Exchange (ETDEWEB)

    Goh, Hock-Seng; /UC, Berkeley /LBL, Berkeley; Ibe, Masahiro; /SLAC

    2009-06-19

    Supersymmetric models with spontaneously broken approximate R-symmetry contains a light spin 0 particle, the R-axion. The properties of the particle can be a powerful probe of the structure of the new physics. In this paper, we discuss the possibilities of the R-axion detection at the LHC experiments. It is challenge to observe this light particle in the LHC environment. However, for typical values in which the mass of the R-axion is a few hundred MeV, we show that those particles can be detected by searching for displaced vertices from R-axion decay.

  16. US Participation in the Solar Orbiter Multi Element Telescope for Imaging and Spectroscopy (METIS) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Multi Element Telescope for Imaging and Spectroscopy, METIS, investigation has been conceived to perform off-limb and near-Sun coronagraphy and is motivated by...

  17. Gregor@night: The future high-resolution stellar spectrograph for the GREGOR solar telescope

    Czech Academy of Sciences Publication Activity Database

    Strassmeier, K.G.; Ilyin, I.V.; Woche, M.; Granzer, T.; Weber, M.; Weingrill, J.; Bauer, S.-M.; Popow, E.; Denker, C.; Schmidt, W.; von der Lühe, O.; Berdyugina, S.; Collados, M.; Koubský, Pavel; Hackman, T.; Mantere, M.J.

    2012-01-01

    Roč. 333, č. 9 (2012), s. 901-910. ISSN 0004-6337 Institutional support: RVO:67985815 Keywords : spesctrographs * telescope Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 1.399, year: 2012

  18. WIMP and Axion Dark Matter

    OpenAIRE

    Kamionkowski, Marc

    1997-01-01

    There is almost universal agreement among cosmologists that most of the matter in the Universe is dark, and there are very good reasons to believe that most of this dark matter must be nonbaryonic. The two leading candidates for this dark matter are axions and weakly-interacting massive particles (WIMPs), such as the neutralino in supersymmetric extensions of the standard model. I discuss the arguments for these two dark-matter candidates and review techniques for discovery of these dark-matt...

  19. Vacuum selection on axionic landscapes

    Science.gov (United States)

    Wang, Gaoyuan; Battefeld, Thorsten

    2016-04-01

    We compute the distribution of minima that are reached dynamically on multi-field axionic landscapes, both numerically and analytically. Such landscapes are well suited for inflationary model building due to the presence of shift symmetries and possible alignment effects (the KNP mechanism). The resulting distribution of dynamically reached minima differs considerably from the naive expectation based on counting all vacua. These differences are more pronounced in the presence of many fields due to dynamical selection effects: while low lying minima are preferred as fields roll down the potential, trajectories are also more likely to get trapped by one of the many nearby minima. We show that common analytic arguments based on random matrix theory in the large D-limit to estimate the distribution of minima are insufficient for quantitative arguments pertaining to the dynamically reached ones. This discrepancy is not restricted to axionic potentials. We provide an empirical expression for the expectation value of such dynamically reached minimas' height and argue that the cosmological constant problem is not alleviated in the absence of anthropic arguments. We further comment on the likelihood of inflation on axionic landscapes in the large D-limit.

  20. Off-limb EUV observations of the solar corona and transients with the CORONAS-F/SPIRIT telescope-coronagraph

    Directory of Open Access Journals (Sweden)

    V. Slemzin

    2008-10-01

    Full Text Available The SPIRIT telescope aboard the CORONAS-F satellite (in orbit from 26 July 2001 to 5 December 2005, observed the off-limb solar corona in the 175 Å (Fe IX, X and XI lines and 304 Å (He II and Si XI lines bands. In the coronagraphic mode the mirror was tilted to image the corona at the distance of 1.1...5 Rsun from the solar center, the outer occulter blocked the disk radiation and the detector sensitivity was enhanced. This intermediate region between the fields of view of ordinary extreme-ultraviolet (EUV telescopes and most of the white-light (WL coronagraphs is responsible for forming the streamer belt, acceleration of ejected matter and emergence of slow and fast solar wind. We present here the results of continuous coronagraphic EUV observations of the solar corona carried out during two weeks in June and December 2002. The images showed a "diffuse" (unresolved component of the corona seen in both bands, and non-radial, ray-like structures seen only in the 175 Å band, which can be associated with a streamer base. The correlations between latitudinal distributions of the EUV brightness in the corona and at the limb were found to be high in 304 Å at all distances and in 175 Å only below 1.5 Rsun. The temporal correlation of the coronal brightness along the west radial line, with the brightness at the underlying limb region was significant in both bands, independent of the distance. On 2 February 2003 SPIRIT observed an expansion of a transient associated with a prominence eruption seen only in the 304 Å band. The SPIRIT data have been compared with the corresponding data of the SOHO LASCO, EIT and UVCS instruments.

  1. Thermal Performance of the Hubble Space Telescope (HST) Solar Array-3 During the Disturbance Verification Test (DVT)

    Science.gov (United States)

    Nguyen, Daniel H.; Skladany, Lynn M.; Prats, Benito D.; Griffin, Thomas J. (Technical Monitor)

    2001-01-01

    The Hubble Space Telescope (HST) is one of NASA's most productive astronomical observatories. Launched in 1990, the HST continues to gather scientific data to help scientists around the world discover amazing wonders of the universe. To maintain HST in the fore front of scientific discoveries, NASA has routinely conducted servicing missions to refurbish older equipment as well as to replace existing scientific instruments with better, more powerful instruments. In early 2002, NASA will conduct its fourth servicing mission to the HST. This servicing mission is named Servicing Mission 3B (SM3B). During SM3B, one of the major refurbishment efforts will be to install new rigid-panel solar arrays as a replacement for the existing flexible-foil solar arrays. This is necessary in order to increase electrical power availability for the new scientific instruments. Prior to installing the new solar arrays on HST, the HST project must be certain that the new solar arrays will not cause any performance degradations to the observatory. One of the major concerns is any disturbance that can cause pointing Loss of Lock (LOL) for the telescope. While in orbit, the solar-array temperature transitions quickly from sun to shadow. The resulting thermal expansion and contraction can cause a "mechanical disturbance" which may result in LOL. To better characterize this behavior, a test was conducted at the European Space Research and Technology Centre (ESTEC) in the Large Space Simulator (LSS) thermal-vacuum chamber. In this test, the Sun simulator was used to simulate on-orbit effects on the solar arrays. This paper summarizes the thermal performance of the Solar Array-3 (SA3) during the Disturbance Verification Test (DVT). The test was conducted between 26 October 2000 and 30 October 2000. Included in this paper are: (1) brief description of the SA3's components and its thermal design; (2) a summary of the on-orbit temperature predictions; (3) pretest thermal preparations; (4) a

  2. X-ray optics for axion helioscopes

    DEFF Research Database (Denmark)

    Jakobsen, Anders Clemen; Pivovaroff, Michael J.; Christensen, Finn Erland

    2013-01-01

    A method of optimizing grazing incidence x-ray coatings in ground based axion helioscopes is presented. Software has been been developed to find the optimum coating when taking both axion spectrum and Micromegas detector quantum efficiency into account. A comparison of the relative effective area...

  3. Some Considerations About Podolsky-Axionic Electrodynamics

    OpenAIRE

    Gaete, Patricio(Departmento de Física and Centro Científico-Tecnológico de Valparaíso, Universidad Técnica Federico Santa María, Valparaiso, Chile)

    2011-01-01

    For a Podolsky-axionic electrodynamics, we compute the interaction potential within the structure of the gauge-invariant but path-dependent variables formalism. The result is equivalent to that of axionic electrodynamics from a new noncommutative approach, up to first order in $\\theta$.

  4. Imaging Extra-Solar Planets with an Ultra-Large Space Telescope

    Science.gov (United States)

    Taylor, Charles R.

    1998-01-01

    NASA's Origins Program is directed toward two main goals: Imaging of galactic evolution in the early universe, and searching for planets orbiting nearby stars. The Next-Generation Space Telescope (NGST), operating at low temperature with an 8-m aperture, is well designed to meet the first goal. The goal of imaging planets orbiting nearby stars is more problematic. One line of investigation has been the ULTIMA concept (Ultra-Large Telescope, Integrated Missions in Astronomy). In this report, I will lay out the resolution requirements for telescopes to achieve the imaging of extrasolar planets, and describe a modeling tool created to investigate the requirements for imaging a planet when it is very near a much brighter star.

  5. Exploring the role of axions and other WISPs in the dark universe

    Energy Technology Data Exchange (ETDEWEB)

    Ringwald, Andreas

    2012-10-18

    Axions and other very weakly interacting slim particles (WISPs) may be non-thermally produced in the early universe and survive as constituents of the dark universe. We describe their theoretical motivation and their phenomenology. A huge region in parameter space spanned by their couplings to photons and their masses can give rise to the observed cold dark matter abundance. A wide range of experiments - direct dark matter searches exploiting microwave cavities, searches for solar axions or WISPs, and lightshining-through-a-wall searches - can probe large parts of this parameter space in the foreseeable future.

  6. Axion string dynamics I: 2+1D

    Science.gov (United States)

    Fleury, Leesa M.; Moore, Guy D.

    2016-05-01

    If the axion exists and if the initial axion field value is uncorrelated at causally disconnected points, then it should be possible to predict the efficiency of cosmological axion production, relating the axionic dark matter density to the axion mass. The main obstacle to making this prediction is correctly treating the axion string cores. We develop a new algorithm for treating the axionic string cores correctly in 2+1 dimensions. When the axionic string cores are given their full physical string tension, axion production is about twice as efficient as in previous simulations. We argue that the string network in 2+1 dimensions should behave very differently than in 3+1 dimensions, so this result cannot be simply carried over to the physical case. We outline how to extend our method to 3+1D axion string dynamics.

  7. Axion String Dynamics I: 2+1D

    CERN Document Server

    Fleury, Leesa M

    2016-01-01

    If the axion exists and if the initial axion field value is uncorrelated at causally disconnected points, then it should be possible to predict the efficiency of cosmological axion production, relating the axionic dark matter density to the axion mass. The main obstacle to making this prediction is correctly treating the axion string cores. We develop a new algorithm for treating the axionic string cores correctly in 2+1 dimensions. When the axionic string cores are given their full physical string tension, axion production is about twice as efficient as in previous simulations. We argue that the string network in 2+1 dimensions should behave very differently than in 3+1 dimensions, so this result cannot be simply carried over to the physical case. We outline how to extend our method to 3+1D axion string dynamics.

  8. Fermion production during and after axion inflation

    International Nuclear Information System (INIS)

    We study derivatively coupled fermions in axion-driven inflation, specifically mϕ2ϕ2 and monodromy inflation, and calculate particle production during the inflationary epoch and the post-inflationary axion oscillations. During inflation, the rolling axion acts as an effective chemical potential for helicity which biases the gravitational production of one fermion helicity over the other. This mechanism allows for efficient gravitational production of heavy fermion states that would otherwise be highly suppressed. Following inflation, the axion oscillates and fermions with both helicities are produced as the effective frequency of the fermion field changes non-adiabatically. For certain values of the fermion mass and axion-fermion coupling strength, the two helicity states are produced asymmetrically, resulting in unequal number-densities of left- and right-helicity fermions

  9. Oscillating Chiral Tensor Spectrum from Axionic Inflation

    CERN Document Server

    Obata, Ippei

    2016-01-01

    We study the axionic inflation with a modulated potential and examine if the primordial tensor power spectrum exhibits oscillatory feature, which is testable with future space-based gravitational wave experiments such as DECIGO and BBO. In the case of the single-field axion monodromy inflation, it turns out that it is difficult to detect the oscillation in the spectrum due to suppression of the sub-Planckian decay constant of axion. On the other hand, in the case of aligned chromo-natural inflation where the axion is coupled to a SU(2) gauge field, it turns out that the sizable oscillation in the tensor spectrum can occur due to the enhancement of chiral gravitational waves sourced by the gauge field. We expect that this feature will be a new probe to axion phenomenologies in early universe through the chiral gravitational waves.

  10. A Search for Axions and massive neutrinos

    CERN Multimedia

    2002-01-01

    This experiment relies on the production of a strong, contamination free (10$ ^{-12} $) source of radioactive $^{125}$I at the ISOLDE facility. Technical developments to achieve the necessary beam intensity are in progress. \\\\ \\\\The possible emission of axions in the 35.5 keV M1 transition of the $^{125}$Te daughter isotope is searched for by the axion analogue of the Mössbauer effect, i.e. the axion resonance absorption in a $^{125}$Te resonance absorber. For this purpose all other radiation emitted from the source is shielded by a non-resonant absorber, which is transparent, however, to axions. The resonance absorption is detected by measurement of subsequently emitted X-rays. A sensitivity to the axion emission branching ratio in the nuclear decay of 10$ ^{-7} $ is strived for.

  11. Fermion production during and after axion inflation

    Energy Technology Data Exchange (ETDEWEB)

    Adshead, Peter; Sfakianakis, Evangelos I. [Department of Physics, University of Illinois at Urbana-Champaign,Urbana, Illinois 61801 (United States)

    2015-11-11

    We study derivatively coupled fermions in axion-driven inflation, specifically m{sub ϕ}{sup 2}ϕ{sup 2} and monodromy inflation, and calculate particle production during the inflationary epoch and the post-inflationary axion oscillations. During inflation, the rolling axion acts as an effective chemical potential for helicity which biases the gravitational production of one fermion helicity over the other. This mechanism allows for efficient gravitational production of heavy fermion states that would otherwise be highly suppressed. Following inflation, the axion oscillates and fermions with both helicities are produced as the effective frequency of the fermion field changes non-adiabatically. For certain values of the fermion mass and axion-fermion coupling strength, the two helicity states are produced asymmetrically, resulting in unequal number-densities of left- and right-helicity fermions.

  12. Bose-Einstein Condensation of Dark Matter Axions

    OpenAIRE

    Sikivie, P.; Yang, Q.

    2009-01-01

    We show that cold dark matter axions thermalize and form a Bose-Einstein condensate. We obtain the axion state in a homogeneous and isotropic universe, and derive the equations governing small axion perturbations. Because they form a BEC, axions differ from ordinary cold dark matter in the non-linear regime of structure formation and upon entering the horizon. Axion BEC provides a mechanism for the production of net overall rotation in dark matter halos, and for the alignment of cosmic microw...

  13. Photon production from the scattering of axions out of a solenoidal magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Guendelman, Eduardo I.; Shilon, Idan [Physics Department, Ben-Gurion University of the Negev, Beer-Sheva 84105 (Israel); Cantatore, Giovanni [Università and INFN Trieste, via Valerio 2, 34127 Trieste (Italy); Zioutas, Konstantin, E-mail: guendel@bgu.ac.il, E-mail: silon@bgu.ac.il, E-mail: cantatore@trieste.infn.it, E-mail: Konstantin.Zioutas@cern.ch [Physics Department, University of Patras, Rio, 26504 Patras (Greece)

    2010-06-01

    We calculate the total cross section for the production of photons from the scattering of axions by a strong inhomogeneous magnetic field in the form of a 2D δ-function, a cylindrical step function and a 2D Gaussian distribution, which can be approximately produced by a solenoidal current. The theoretical result is used to estimate the axion-photon conversion probability which could be expected in a reasonable experimental situation. Comparison between the 2D conversion probabilities for QCD inspired axions and those derived by applying the celebrated 1D calculation of the (inverse) coherent Primakoff effect is made using an averaging prescription procedure of the 1D case. We also consider scattering at a resonance E{sub axion} ∼ m{sub axion}, which corresponds to the scattering from a δ-function and gives the most enhanced results. Finally, we analyze the results of this work in the astrophysical extension to suggest a way in which they may be directed to a solution to some basic solar physics problems and, in particular, the coronal heating problem.

  14. Large Field Inflation from Axion Mixing

    CERN Document Server

    Shiu, Gary; Ye, Fang

    2015-01-01

    We study the general multi-axion systems, focusing on the possibility of large field inflation driven by axions. We find that through axion mixing from a non-diagonal metric on the moduli space and/or from St\\"uckelberg coupling to a U(1) gauge field, an effectively super-Planckian decay constant can be generated without the need of "alignment" in the axion decay constants. We also investigate the consistency conditions related to the gauge symmetries in the multi-axion systems, such as vanishing gauge anomalies and the potential presence of generalized Chern-Simons terms. Our scenario applies generally to field theory models whose axion periodicities are intrinsically sub-Planckian, but it is most naturally realized in string theory. The types of axion mixings invoked in our scenario appear quite commonly in D-brane models, and we present its implementation in type II superstring theory. Explicit stringy models exhibiting all the characteristics of our ideas are constructed within the frameworks of Type IIA ...

  15. Axion mechanism of Sun luminosity, dark matter and extragalactic background light

    OpenAIRE

    Rusov, V. D.; Sharf, I. V.; Tarasov, V. A.; Eingorn, M. V.; Smolyar, V. P.; Vlasenko, D. S.; Zelentsova, T. N.; Linnik, E. P.; Beglaryan, M. E.

    2013-01-01

    We show the existence of the strong inverse correlation between the temporal variations of the toroidal component of the magnetic field in the solar tachocline (the bottom of the convective zone) and the Earth magnetic field (the Y-component). The possibility that the hypothetical solar axions, which can transform into photons in external electric or magnetic fields (the inverse Primakoff effect), can be the instrument by which the magnetic field of the Sun convective zone modulates the magne...

  16. Hard X-ray imaging from the solar probe. [X ray telescope and mission planning

    Science.gov (United States)

    Hudson, H. S.

    1978-01-01

    The solar probe offers a platform with particular advantages for studying solar nonthermal plasma processes via the observations of hard X-radiation from energetic electrons in the chromosphere and corona, these include (1) high sensitivity, (2) a second line of sign (in addition to the earth's) that can aid in three dimensional reconstruction of the source distribution, and, (3) the possibility of correlation with direct measurements of the nonthermal particles from the probe itself.

  17. New potentials for string axion inflation

    Science.gov (United States)

    Kobayashi, Tatsuo; Oikawa, Akane; Otsuka, Hajime

    2016-04-01

    We propose a new type of axion inflation with complex structure moduli in the framework of type IIB superstring theory compactified on the Calabi-Yau manifold. The inflaton is identified as the axion for the complex structure moduli whose potential is originating from instantonic corrections appearing through the period vector of the mirror Calabi-Yau manifold. The axionic shift symmetry is broken down to the discrete one by the inclusion of the instantonic correction and certain three-form fluxes. Our proposed inflation scenario is compatible with Kähler moduli stabilization. We also study a typical reheating temperature in the case of complex structure moduli inflation.

  18. A 2nd generation cosmic axion experiment

    OpenAIRE

    Hagmann, C; Stoeffl, W.; Van Bibber, K.; Daw, E.; Kinion, D.; Rosenberg, L; Sikivie, P.; Sullivan, N.; D. Tanner; Moltz, D.; Nezrick, F.; Turner, M; Golubev, N.; Kravchuk, L.

    1995-01-01

    An experiment is described to detect dark matter axions trapped in the halo of our galaxy. Galactic axions are converted into microwave photons via the Primakoff effect in a static background field provided by a superconducting magnet. The photons are collected in a high Q microwave cavity and detected by a low noise receiver. The axion mass range accessible by this experiment is 1.3-13 micro-eV. The expected sensitivity will be roughly 50 times greater than achieved by previous experiments i...

  19. A 2nd generation cosmic axion experiment

    CERN Document Server

    Hagmann, C A; Van Bibber, K; Daw, E J; Kinion, D S; Rosenberg, L J; Sikivie, P; Sullivan, N; Tanner, D B; Moltz, D M; Nezrick, F A; Turner, M; Golubev, N A; Kravchuk, L V

    1995-01-01

    An experiment is described to detect dark matter axions trapped in the halo of our galaxy. Galactic axions are converted into microwave photons via the Primakoff effect in a static background field provided by a superconducting magnet. The photons are collected in a high Q microwave cavity and detected by a low noise receiver. The axion mass range accessible by this experiment is 1.3-13 micro-eV. The expected sensitivity will be roughly 50 times greater than achieved by previous experiments in this mass range. The assembly of the detector is well under way at LLNL and data taking will start in mid-1995.

  20. Power Challenges of Large Scale Research Infrastructures: the Square Kilometer Array and Solar Energy Integration; Towards a zero-carbon footprint next generation telescope

    OpenAIRE

    Barbosa, Domingos; Márquez, Gonzalo Lobo; Ruiz, Valeriano; Silva, Manuel; Verdes-Montenegro, Lourdes; Santander-Vela, Juande; Maia, Dalmiro; Antón, Sonia; van Ardenne, Arnold; Vetter, Matthias; Kramer, Michael; Keller, Reinhard; Pereira, Nuno; Silva, Vitor; Consortium, The BIOSTIRLING

    2012-01-01

    The Square Kilometer Array (SKA) will be the largest Global science project of the next two decades. It will encompass a sensor network dedicated to radioastronomy, covering two continents. It will be constructed in remote areas of South Africa and Australia, spreading over 3000Km, in high solar irradiance latitudes. Solar Power supply is therefore an option to power supply the SKA and contribute to a zero carbon footprint next generation telescope. Here we outline the major characteristics o...

  1. The Dutch Open Telescope

    OpenAIRE

    Rutten, R. J.; Hammerschlag, R.H.; Bettonvil, F.C.M.

    2001-01-01

    The Dutch Open Telescope is a new and novel optical solar telescope on La Palma. It aims at high resolution by combining an excel- lent site on La Palma with an open tower and an open telescope and leads the way to large-aperture high resolution telescopes. We brie y review the DOT principle, structure and goals. More information is found at the DOT website.

  2. Gravitational Waves from Axion Monodromy

    CERN Document Server

    Hebecker, Arthur; Rompineve, Fabrizio; Witkowski, Lukas T

    2016-01-01

    Large field inflation is arguably the simplest and most natural variant of slow-roll inflation. Axion monodromy may be the most promising framework for realising this scenario. As one of its defining features, the long-range polynomial potential possesses short-range, instantonic modulations. These can give rise to a series of local minima in the post-inflationary region of the potential. We show that for certain parameter choices the inflaton populates more than one of these vacua inside a single Hubble patch. This corresponds to a dynamical phase decomposition, analogously to what happens in the course of thermal first-order phase transitions. In the subsequent process of bubble wall collisions, the lowest-lying axionic minimum eventually takes over all space. Our main result is that this violent process sources gravitational waves, very much like in the case of a first-order phase transition. We compute the energy density and peak frequency of the signal, which can lie anywhere in the mHz-GHz range, possib...

  3. Limitations Placed on the Time Coverage, Isoplanatic Patch Size and Exposure Time for Solar Observations Using Image Selection Procedures in the Presence of Telescope Aberrations

    Science.gov (United States)

    Beckers, J. M.; Rimmele, T. R.

    1996-12-01

    Image selection, adaptive optics and post-facto image restoration methods are all techniques being used for diffraction limited imaging with ground-based solar and stellar telescopes. Often these techniques are used in a hybrid form like e.g. the application of adaptive optics and/or post-facto image restoration in combination with already good images obtained by image selection in periods of good seeing. Fried (JOSA 56, 1372, 1966), Hecquet and Coupinot (J. Optics/Paris 16, 21, 1985) and Beckers ("Solar and Stellar Granulation", Kluwer, Rutten & Severino Eds, 55, 1988) already discussed the usefulness of image selection, or the "Lucky Observer" mode, for high resolution imaging. All assumed perfect telescope optics. In case of moderate telescope aberrations image selection can still lead to diffraction limited imaging but only when the atmospheric wavefront aberration happens to compensate that of the telescope. In this "Very Lucky Observer" mode the probability of obtaining a good image is reduced over the un-aberrated case, as are the size of the isoplanatic patch and the exposure time. We describe an analysis of these effects for varying telescope aberrations. These result in a strong case for the removal of telescope aberrations either by initial implementation or by the use of slow active optics.

  4. The direct photograph of solar faculae and sunspots with a balloon-borne 10 cm telescope, (3)

    International Nuclear Information System (INIS)

    With the flight in September, 1977, of a balloon-borne 10 cm solar telescope, direct photographs of faculae and sunspots were successfully taken at wavelength near 5300 A. (1) In the measurement of brightness of 662 faculae in the places closer to the photosphere center (two regions at 76% and 87% of the radius), the valves were 9.2% and 16.2% respectively brighter in comparison of the surrounding photosphere. The faculae are at higher temperature than the photosphere, 500 k (facula diameter of 1 sec angle) to 1000 k (facula diameter of 0.2 sec angle). (2) At a place close to the umbra within the penumbra of sunspots, there is brightness equal to that of the photosphere. (3) As the result of comparing the polar-region faculae by balloon observation and the soft X-ray bright points by sky-lab observation in 1973, it was found that both were not shining simultaneously. (Mori, K.)

  5. Improving characterization and modeling of polarization effects in the calibration retarders for the Daniel K. Inouye Solar Telescope

    Science.gov (United States)

    Sueoka, Stacey

    2016-05-01

    The Daniel K Inouye Solar Telescope (DKIST) will have a suite of first-light polarimetric instrumentation requiring calibration of a complex off-axis optical path. The DKIST polarization calibration process requires modeling and fitting for several optical, thermal and mechanical effects. Three dimensional polarization ray trace codes (PolarisM) allow modeling of polarization errors inherent in assuming a linear retardation as a function of angle of incidence for our calibration retarders at Gregorian and Coudé foci. Stress induced retardation effects from substrate and coating absorption, mechanical mounting stresses, and inherent polishing uniformity tolerances introduce polarization effects at significant levels. These effects require careful characterization and modeling for mitigation during design, construction, calibration and science observations. Modeling efforts, amplitude estimates and mitigation efforts will be presented for the suite of DKIST calibration optics planned for first-light operations.

  6. Ke Alahaka Program of the Advanced Technology Solar Telescope (ATST) Mitigation Initiative Provides STEM Workshops for Native Hawaiian Students

    Science.gov (United States)

    Coopersmith, A.; Cie, D. K.; Naho`olewa, D.; Chirico, J.

    2012-12-01

    The Advanced Technology Solar Telescope (ATST) Mitigation Initiative and the Kahikina O Ka Lā Program are NSF-funded projects at the University of Hawai`i Maui College. These projects will provide instruction and activities intended to increase diversity in STEM or STEM-related careers. Ke Alahaka, the 2012 summer bridge program, was offered to Native Hawaiian high-school students who indicated an interest in STEM areas. Three STEM-content workshops were offered including Marine Science, Sustainable Energy Technology, and Computer Science and Engineering. Students attended hands-on classes three days a week for a month concentrating on only one of the three topics. On the other days, students participated in a Hawaiian Studies course designed to provide a cultural context for the STEM instruction. Focus groups and other program assessments indicate that 50% of the 60 students attending the workshops intend to pursue a STEM major during their undergraduate studies.

  7. Effect of Solar Exposure on the Atomic Oxygen Erosion of Hubble Space Telescope Aluminized-Teflon Thermal Shields

    Science.gov (United States)

    Guo, Aobo; Ashmead, Claire C.; deGroh, Kim K.

    2012-01-01

    When exposed to low Earth orbital (LEO) environment, external spacecraft materials degrade due to radiation, thermal cycling, micrometeoroid and debris impacts, and atomic oxygen (AO) interaction. Collisions between AO and spacecraft can result in oxidation of external spacecraft surface materials, which can lead to erosion and severe structural and/or optical property deterioration. It is therefore essential to understand the AO erosion yield (Ey), the volume loss per incident oxygen atom (cu cm/atom), of polymers to assure durability of spacecraft materials. The objective of this study was to determine whether solar radiation exposure can increase the rate of AO erosion of polymers in LEO. The material studied was a section of aluminized-Teflon (DuPont) fluorinated ethylene propylene (Al-FEP) thermal shield exposed to space on the Hubble Space Telescope (HST) for 8.25 years. Retrieved samples were sectioned from the circular thermal shield and exposed to ground laboratory thermal energy AO. The results indicate that the average Ey of the solar facing HST Al-FEP was 1.9 10(exp -24)cu cm/atom, while the average Ey of the anti-solar HST Al-FEP was 1.5 10(exp -24)cu cm/atom. The Ey of the pristine samples was 1.6- 1.7 10(exp -24)cu cm/atom. These results indicate that solar exposure affects the post-flight erosion rate of FEP in a plasma asher. Therefore, it likely affects the erosion rate while in LEO.

  8. Axion monodromy inflation with sinusoidal corrections

    CERN Document Server

    Kobayashi, Tatsuo; Yamaguchi, Yuya

    2014-01-01

    We study the axion monodromy inflation with a non-perturbatively generated sinusoidal term. The potential form is a mixture between the natural inflation and the axion monodromy inflation potentials. The sinusoidal term is subdominant in the potential, but leaves significant effects on the resultant fluctuation generated during inflation. A larger tensor-to-scalar ratio can be obtained in our model. We study two scenarios, single inflation scenario and the double inflation scenario. In the first scenario, the axion monodromy inflation with a sufficient number of e-fold generates a larger tensor-to-scalar ratio about $0.1 - 0.15$ but also a tiny running of spectral index. In the second scenario of double inflation, axion monodromy inflation is its first stage and, we assume another inflation follows. In this case, our model can realize a larger tensor-to-scalar ratio and a large negative running of spectral index simultaneously.

  9. Nonrelativistic Effective Field Theory for Axions

    CERN Document Server

    Braaten, Eric; Zhang, Hong

    2016-01-01

    Axions can be described by a relativistic field theory with a real scalar field $\\phi$ whose self-interaction potential is a periodic function of $\\phi$. Low-energy axions, such as those produced in the early universe by the vacuum misalignment mechanism, can be described more simply by a nonrelativistic effective field theory with a complex scalar field $\\psi$ whose effective potential is a function of $\\psi^*\\psi$. We determine the coefficients in the expansion of the effective potential to fifth order in $\\psi^*\\psi$ by matching low-energy axion scattering amplitudes. In order to describe a Bose-Einstein condensate of axions that is too dense to expand the effective potential in powers of $\\psi^*\\psi$, we develop a sequence of systematically improvable approximations to the effective potential that include terms of all orders in $\\psi^*\\psi$.

  10. Cavity Microwave Searches for Cosmological Axions

    CERN Document Server

    CERN. Geneva

    2005-01-01

    The lecture will cover the searches for dark matter axions based on the microwave cavity experiment of Sikivie. The topics will begin with a brief overview of halo dark matter, and the axion as a candidate. The principle of resonant conversion of axions in an external magnetic field will be described, and practical considerations in optimizing the experiment as a signal-to-noise problem. A major focus of the lecture will be the two complementary strategies for ultra-low noise detection of the microwave photons - the "photon-as-wave" approach (i.e. conventional heterojunction amplifiers and soon quantum-limited SQUID devices), and "photon-as-particle" (i.e. Rydberg-atom single-quantum detection). Experimental results will be presented; these experiments have already reached well into the range of sensitivity to exclude plausible axion models, for limited ranges of mass. The lecture will conclude with a discussion of future plans and challenges for the microwave ca...

  11. Dark-matter QCD-axion searches.

    Science.gov (United States)

    Rosenberg, Leslie J

    2015-10-01

    In the late 20th century, cosmology became a precision science. Now, at the beginning of the next century, the parameters describing how our universe evolved from the Big Bang are generally known to a few percent. One key parameter is the total mass density of the universe. Normal matter constitutes only a small fraction of the total mass density. Observations suggest this additional mass, the dark matter, is cold (that is, moving nonrelativistically in the early universe) and interacts feebly if at all with normal matter and radiation. There's no known such elementary particle, so the strong presumption is the dark matter consists of particle relics of a new kind left over from the Big Bang. One of the most important questions in science is the nature of this dark matter. One attractive particle dark-matter candidate is the axion. The axion is a hypothetical elementary particle arising in a simple and elegant extension to the standard model of particle physics that nulls otherwise observable CP-violating effects (where CP is the product of charge reversal C and parity inversion P) in quantum chromo dynamics (QCD). A light axion of mass 10(-(6-3)) eV (the invisible axion) would couple extraordinarily weakly to normal matter and radiation and would therefore be extremely difficult to detect in the laboratory. However, such an axion is a compelling dark-matter candidate and is therefore a target of a number of searches. Compared with other particle dark-matter candidates, the plausible range of axion dark-matter couplings and masses is narrowly constrained. This focused search range allows for definitive searches, where a nonobservation would seriously impugn the dark-matter QCD-axion hypothesis. Axion searches use a wide range of technologies, and the experiment sensitivities are now reaching likely dark-matter axion couplings and masses. This article is a selective overview of the current generation of sensitive axion searches. Not all techniques and experiments

  12. RATAN-600 radio telescope in the 24th solar-activity cycle. III. System of data acquisition and control of the solar spectral facility

    Science.gov (United States)

    Baldin, S. V.; Garaimov, V. I.

    2011-07-01

    We report the development of a multichannel data acquisition and control system for the Spectral and Polarization High-Resolution Solar Research System, installed at the RATAN-600 radio telescope. This facility provides high-speed registration of signals from 240 channels and controls the preparation for observations and the process of automatic observations. The hardware is made in the form factor of 3U Evromekhanika modules. The measurement facility is controlled by the software based on the QT cross-platform library (the open source version), which can be run both on Linux and Windows operating systems. The data are written to a magnetic carrier and then transferred to the computer network of the Special Astrophysical Observatory for archiving, and can be accessed by external users.

  13. Gravity wave and model-independent axion

    CERN Document Server

    Kim, Jihn E

    2016-01-01

    In this short comment, we notice that the model-independent axion contribution to the graviton mass at just outside the Schwarzschild radius is completely negligible in GW150914. The model-independent axion contribution to the graviton mass at the order $10^{-22}\\,$eV might be possible for merger of black holes of mass of order $2\\times 10^{14}\\,$kg.

  14. Axion Research at CAPP/IBS

    Science.gov (United States)

    Youn, Sungwoo

    2016-07-01

    The axion, a hypothetical fundamental particle, was postulated as an attractive solution to the CP problem in quantum chromodynamics and believed to be an ideal candidate for the cold dark matter. The Center for Axion and Precision Physics Research of the Institute for Basic Science has launched a state of the art experiment to search for the hypothesised new particle using microwave resonant cavities. I will discuss R&D efforts at our center and plans for the experiment.

  15. Power Challenges of Large Scale Research Infrastructures: the Square Kilometer Array and Solar Energy Integration; Towards a zero-carbon footprint next generation telescope

    CERN Document Server

    Barbosa, Domingos; Ruiz, Valeriano; Silva, Manuel; Verdes-Montenegro, Lourdes; Santander-Vela, Juande; Maia, Dalmiro; Antón, Sonia; van Ardenne, Arnold; Vetter, Matthias; Kramer, Michael; Keller, Reinhard; Pereira, Nuno; Silva, Vitor

    2012-01-01

    The Square Kilometer Array (SKA) will be the largest Global science project of the next two decades. It will encompass a sensor network dedicated to radioastronomy, covering two continents. It will be constructed in remote areas of South Africa and Australia, spreading over 3000Km, in high solar irradiance latitudes. Solar Power supply is therefore an option to power supply the SKA and contribute to a zero carbon footprint next generation telescope. Here we outline the major characteristics of the SKA and some innovation approaches on thermal solar energy Integration with SKA prototypes.

  16. Observations of Oppositely Directed Umbral Wavefronts Rotating in Sunspots Obtained from the New Solar Telescope of BBSO

    Science.gov (United States)

    Su, J. T.; Ji, K. F.; Cao, W.; Banerjee, D.; Priya, T. G.; Zhao, J. S.; Bai, X. Y.; Chen, J.; Zhang, M.; Ji, H. S.

    2016-02-01

    We study the umbral waves as observed by chromospheric imaging observations of two sunspots with the New Solar Telescope at the Big Bear Solar Observatory. We find that the wavefronts (WFs) rotate clockwise and form a one-armed spiral structure in the first sunspot, whereas two- and three-armed structures arise in the second sunspot where the WFs rotate anticlockwise and clockwise alternately. All the spiral arms display propagation outwards and become running penumbral waves once they cross the umbral boundaries, suggesting that the umbral and penumbral waves propagate along the same inclined field lines. We propose that the one-armed spiral structure may be produced by the WF reflections at the chromospheric umbral light bridge, and the multi-armed spirals may be related to the twist of the magnetic field in the umbra. Additionally, the time lag of the umbral oscillations in between the data of He i 10830 Å and {{H}}α -0.4 Å is ∼17 s, and it is ∼60 s for that in between the data of 304 Å and {{H}}α -0.4 Å. This indicates that these disturbances are slow magnetoacoustic waves in nature, and that they propagate upward along the inclined lines with fast radial expansions causing horizontal velocities of the running waves.

  17. Axion mechanism of Sun luminosity, dark matter and extragalactic background light

    CERN Document Server

    Rusov, V D; Tarasov, V A; Eingorn, M V; Smolyar, V P; Vlasenko, D S; Zelentsova, T N; Linnik, E P; Beglaryan, M E

    2013-01-01

    We show the existence of the strong inverse correlation between the temporal variations of the toroidal component of the magnetic field in the solar tachocline (the bottom of the convective zone) and the Earth magnetic field (the Y-component). The possibility that the hypothetical solar axions, which can transform into photons in external electric or magnetic fields (the inverse Primakoff effect), can be the instrument by which the magnetic field of the Sun convective zone modulates the magnetic field of the Earth is considered. We propose the axion mechanism of Sun luminosity and "solar dynamo -- geodynamo" connection, where the energy of one of the solar axion flux components emitted in M1 transition in 57Fe nuclei is modulated at first by the magnetic field of the solar tachocline zone (due to the inverse coherent Primakoff effect) and after that is resonantly absorbed in the core of the Earth, thereby playing the role of the energy modulator of the Earth magnetic field. Within the framework of this mechan...

  18. An experiment to search for galactic axions

    International Nuclear Information System (INIS)

    Results are presented from a search for axions in the mass range of .51 X 10-5 to 1 X 10-5eV, which may make up the dark matter halo of the galaxy. The detector used in the search consists of a microwave cavity placed in the strong magnetic field of a superconducting solenoid magnet. The energy in the TM010 mode of the cavity is monitored by a sensitive microwave receiver as the frequency of the mode is swept. The predicted experimental signature of galactic halo axions is a narrow signal, with a Qa = f/Δf ∼ 3 X 106, which is expected when the resonant frequency of the cavity corresponds to the mass of the axion. An experimental limit on the coupling times the density of (gaγγ/ma)2 ρa ≤ 2 x 10-40 for an axion linewidth ≤ 400 Hz with a 97% confidence level has been obtained. The theoretical prediction is (gaγγ/ma)2ρa ∼ 3.9 x 10-44 with ρa = 300 MeV/cm3. The corresponding limit in gaγγ ≤ 7 x 10-14 GeV-1 at an axion frequency f = 2 GeV and depends linearly on axion mass

  19. Black hole formation from axion stars

    CERN Document Server

    Helfer, Thomas; Clough, Katy; Fairbairn, Malcolm; Lim, Eugene A; Becerril, Ricardo

    2016-01-01

    The classical equations of motion for an axion with potential $V(\\phi)=m_a^2f_a^2 [1-\\cos (\\phi/f_a)]$ possess quasi-stable, localized, oscillating solutions, which we refer to as "axion stars". We study, for the first time, collapse of axion stars numerically using the full non-linear Einstein equations of general relativity and the full non-perturbative cosine potential. We map regions on an "axion star stability diagram", parameterized by the initial ADM mass, $M_{\\rm ADM}$, and axion decay constant, $f_a$. We identify three regions of the parameter space: i) long-lived oscillating axion star solutions, with a base frequency, $m_a$, modulated by self-interactions, ii) collapse to a BH and iii) complete dispersal due to gravitational cooling and interactions. We locate the boundaries of these three regions and an approximate "triple point" $(M_{\\rm TP},f_{\\rm TP})\\sim (2.4 M_{pl}^2/m_a,0.3 M_{pl})$. For $f_a$ below the triple point BH formation proceeds during winding (in the complex $U(1)$ picture) of the ...

  20. Photon - axion conversions in a periodic electromagnetic field with axion frequency

    International Nuclear Information System (INIS)

    The conversion of photons into axions in a periodic external electromagnetic field with axion frequency is considered in detail by Feynman methods. The differential cross sections are given. It is shown that there is a resonant conversion for the considered process. (author)

  1. The 26 December 2001 Solar Event Responsible for GLE63. I. Observations of a Major Long-Duration Flare with the Siberian Solar Radio Telescope

    CERN Document Server

    Grechnev, V V

    2016-01-01

    Ground Level Enhancements (GLEs) of cosmic-ray intensity occur, on average, once a year. Due to their rareness, studying the solar sources of GLEs is especially important to approach understanding their origin. The SOL2001-12-26 eruptive-flare event responsible for GLE63 seems to be challenging in some aspects. Deficient observations limited its understanding. Analysis of extra observations found for this event provided new results shading light on the flare. This article addresses the observations of this flare with the Siberian Solar Radio Telescope (SSRT). Taking advantage of its instrumental characteristics, we analyze the detailed SSRT observations of a major long-duration flare at 5.7 GHz without cleaning the images. The analysis confirms that the source of GLE63 was associated with an event in active region 9742 that comprised two flares. The first flare (04:30-05:03 UT) reached a GOES importance of about M1.6. Two microwave sources were observed, whose brightness temperatures at 5.7 GHz exceeded 10 MK...

  2. Discovering the QCD Axion with Black Holes and Gravitational Waves

    OpenAIRE

    Arvanitaki, Asimina; Baryakhtar, Masha; Huang, Xinlu

    2014-01-01

    Advanced LIGO may be the first experiment to detect gravitational waves. Through superradiance of stellar black holes, it may also be the first experiment to discover the QCD axion with decay constant above the GUT scale. When an axion's Compton wavelength is comparable to the size of a black hole, the axion binds to the black hole, forming a "gravitational atom." Through the superradiance process, the number of axions occupying the bound levels grows exponentially, extracting energy and angu...

  3. Resolving the Fan-spine Reconnection Geometry of a Small-scale Chromospheric Jet Event with the New Solar Telescope

    Science.gov (United States)

    Zeng, Zhicheng; Chen, Bin; Ji, Haisheng; Goode, Philip R.; Cao, Wenda

    2016-03-01

    Jets are ubiquitously present in both quiet and active regions on the Sun. They are widely believed to be driven by magnetic reconnection. A fan-spine structure has been frequently reported in some coronal jets and flares, and has been regarded as a signature of ongoing magnetic reconnection in a topology consisting of a magnetic null connected by a fan-like separatrix surface and a spine. However, for small-scale chromospheric jets, clear evidence of such structures is rather rare, although it has been implied in earlier works that showed an inverted-Y-shaped feature. Here we report high-resolution (0.″16) observations of a small-scale chromospheric jet obtained by the New Solar Telescope (NST) using 10830 Å filtergrams. Bi-directional flows were observed across the separatrix regions in the 10830 Å images, suggesting that the jet was produced due to magnetic reconnection. At the base of the jet, a fan-spine structure was clearly resolved by the NST, including the spine and the fan-like surface, as well as the loops before and after the reconnection. A major part of this fan-spine structure, with the exception of its bright footpoints and part of the base arc, was invisible in the extreme ultraviolet and soft X-ray images (observed by the Atmosphere Imaging Assembly and the X-Ray Telescope, respectively), indicating that the reconnection occurred in the upper chromosphere. Our observations suggest that the evolution of this chromospheric jet is consistent with a two-step reconnection scenario proposed by Török et al.

  4. Dutch Open Telescope: Status and Prospects

    OpenAIRE

    Rutten, R. J.; Hammerschlag, R.H.; Bettonvil, F.C.M.

    2001-01-01

    The Dutch Open Telescope represents a new solar telescope concept. Being open rather than evacuated, it leads the way to large- aperture high resolution telescopes. It is now being installed on La Palma.

  5. MASS AND ENERGY OF ERUPTING SOLAR PLASMA OBSERVED WITH THE X-RAY TELESCOPE ON HINODE

    International Nuclear Information System (INIS)

    We investigate seven eruptive plasma observations by Hinode/XRT. Their corresponding EUV and/or white light coronal mass ejection features are visible in some events. Five events are observed in several passbands in X-rays, which allows for the determination of the eruptive plasma temperature using a filter ratio method. We find that the isothermal temperatures vary from 1.6 to 10 MK. These temperatures are an average weighted toward higher temperature plasma. We determine the mass constraints of eruptive plasmas by assuming simplified geometrical structures of the plasma with isothermal plasma temperatures. This method provides an upper limit to the masses of the observed eruptive plasmas in X-ray passbands since any clumping causes the overestimation of the mass. For the other two events, we assume the temperatures are at the maximum temperature of the X-ray Telescope (XRT) temperature response function, which gives a lower limit of the masses. We find that the masses in XRT, ∼3 × 1013-5 × 1014 g, are smaller in their upper limit than the total masses obtained by LASCO, ∼1 × 1015 g. In addition, we estimate the radiative loss, thermal conduction, thermal, and kinetic energies of the eruptive plasma in X-rays. For four events, we find that the thermal conduction timescales are much shorter than the duration of eruption. This result implies that additional heating during the eruption may be required to explain the plasma observations in X-rays for the four events

  6. THERMAL PROPERTIES OF A SOLAR CORONAL CAVITY OBSERVED WITH THE X-RAY TELESCOPE ON HINODE

    International Nuclear Information System (INIS)

    Coronal cavities are voids in coronal emission often observed above high latitude filament channels. Sometimes, these cavities have areas of bright X-ray emission in their centers. In this study, we use data from the X-ray Telescope (XRT) on the Hinode satellite to examine the thermal emission properties of a cavity observed during 2008 July that contains bright X-ray emission in its center. Using ratios of XRT filters, we find evidence for elevated temperatures in the cavity center. The area of elevated temperature evolves from a ring-shaped structure at the beginning of the observation, to an elongated structure two days later, finally appearing as a compact round source four days after the initial observation. We use a morphological model to fit the cavity emission, and find that a uniform structure running through the cavity does not fit the observations well. Instead, the observations are reproduced by modeling several short cylindrical cavity 'cores' with different parameters on different days. These changing core parameters may be due to some observed activity heating different parts of the cavity core at different times. We find that core temperatures of 1.75 MK, 1.7 MK, and 2.0 MK (for July 19, July 21, and July 23, respectively) in the model lead to structures that are consistent with the data, and that line-of-sight effects serve to lower the effective temperature derived from the filter ratio.

  7. Small field axion inflation with sub-Planckian decay constant

    CERN Document Server

    Kadota, Kenji; Oikawa, Akane; Omoto, Naoya; Otsuka, Hajime; Tatsuishi, Takuya H

    2016-01-01

    We study an axion inflation model recently proposed within the framework of type IIB superstring theory, where we pay a particular attention to a sub-Planckian axion decay constant. Our axion potential can lead to the small field inflation with a small tensor-to-scalar ratio, and a typical reheating temperature can be as low as GeV.

  8. DEBRIS DISKS AROUND SOLAR-TYPE STARS: OBSERVATIONS OF THE PLEIADES WITH THE SPITZER SPACE TELESCOPE

    International Nuclear Information System (INIS)

    We present Spitzer MIPS observations at 24 μm of 37 solar-type stars in the Pleiades and combine them with previous observations to obtain a sample of 71 stars. We report that 23 stars, or 32% ± 6.8%, have excesses at 24 μm at least 10% above their photospheric emission. We compare our results with studies of debris disks in other open clusters and with a study of A stars to show that debris disks around solar-type stars at 115 Myr occur at nearly the same rate as around A-type stars. We analyze the effects of binarity and X-ray activity on the excess flux. Stars with warm excesses tend not to be in equal-mass binary systems, possibly due to clearing of planetesimals by binary companions in similar orbits. We find that the apparent anti-correlations in the incidence of excess and both the rate of stellar rotation and also the level of activity as judged by X-ray emission are statistically weak.

  9. The Substructure of the Solar Corona Observed in the Hi-C Telescope

    Science.gov (United States)

    Winebarger, A.; Cirtain, J.; Golub, L.; DeLuca, E.; Savage, S.; Alexander, C.; Schuler, T.

    2014-01-01

    In the summer of 2012, the High-resolution Coronal Imager (Hi-C) flew aboard a NASA sounding rocket and collected the highest spatial resolution images ever obtained of the solar corona. One of the goals of the Hi-C flight was to characterize the substructure of the solar corona. We therefore calculate how the intensity scales from a low-resolution (AIA) pixels to high-resolution (Hi-C) pixels for both the dynamic events and "background" emission (meaning, the steady emission over the 5 minutes of data acquisition time). We find there is no evidence of substructure in the background corona; the intensity scales smoothly from low-resolution to high-resolution Hi-C pixels. In transient events, however, the intensity observed with Hi-C is, on average, 2.6 times larger than observed with AIA. This increase in intensity suggests that AIA is not resolving these events. This result suggests a finely structured dynamic corona embedded in a smoothly varying background.

  10. Discovery of Finely Structured Dynamic Solar Corona Observed in the Hi-C Telescope

    Science.gov (United States)

    Winebarger, A.; Cirtain, J.; Golub, L.; DeLuca, E.; Savage, S.; Alexander, C.; Schuler, T.

    2014-01-01

    In the summer of 2012, the High-resolution Coronal Imager (Hi-C) flew aboard a NASA sounding rocket and collected the highest spatial resolution images ever obtained of the solar corona. One of the goals of the Hi-C flight was to characterize the substructure of the solar corona. We therefore examine how the intensity scales from AIA resolution to Hi-C resolution. For each low-resolution pixel, we calculate the standard deviation in the contributing high-resolution pixel intensities and compare that to the expected standard deviation calculated from the noise. If these numbers are approximately equal, the corona can be assumed to be smoothly varying, i.e. have no evidence of substructure in the Hi-C image to within Hi-C's ability to measure it given its throughput and readout noise. A standard deviation much larger than the noise value indicates the presence of substructure. We calculate these values for each low-resolution pixel for each frame of the Hi-C data. On average, 70 percent of the pixels in each Hi-C image show no evidence of substructure. The locations where substructure is prevalent is in the moss regions and in regions of sheared magnetic field. We also find that the level of substructure varies significantly over the roughly 160 s of the Hi-C data analyzed here. This result indicates that the finely structured corona is concentrated in regions of heating and is highly time dependent.

  11. MASS AND ENERGY OF ERUPTING SOLAR PLASMA OBSERVED WITH THE X-RAY TELESCOPE ON HINODE

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jin-Yi; Moon, Yong-Jae; Kim, Kap-Sung [Department of Astronomy and Space Science, Kyung Hee University, Yongin, Gyeonggi 446-701 (Korea, Republic of); Raymond, John C.; Reeves, Katharine K., E-mail: jlee@khu.ac.kr [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)

    2015-01-10

    We investigate seven eruptive plasma observations by Hinode/XRT. Their corresponding EUV and/or white light coronal mass ejection features are visible in some events. Five events are observed in several passbands in X-rays, which allows for the determination of the eruptive plasma temperature using a filter ratio method. We find that the isothermal temperatures vary from 1.6 to 10 MK. These temperatures are an average weighted toward higher temperature plasma. We determine the mass constraints of eruptive plasmas by assuming simplified geometrical structures of the plasma with isothermal plasma temperatures. This method provides an upper limit to the masses of the observed eruptive plasmas in X-ray passbands since any clumping causes the overestimation of the mass. For the other two events, we assume the temperatures are at the maximum temperature of the X-ray Telescope (XRT) temperature response function, which gives a lower limit of the masses. We find that the masses in XRT, ∼3 × 10{sup 13}-5 × 10{sup 14} g, are smaller in their upper limit than the total masses obtained by LASCO, ∼1 × 10{sup 15} g. In addition, we estimate the radiative loss, thermal conduction, thermal, and kinetic energies of the eruptive plasma in X-rays. For four events, we find that the thermal conduction timescales are much shorter than the duration of eruption. This result implies that additional heating during the eruption may be required to explain the plasma observations in X-rays for the four events.

  12. DISCOVERY OF FINELY STRUCTURED DYNAMIC SOLAR CORONA OBSERVED IN THE Hi-C TELESCOPE

    Energy Technology Data Exchange (ETDEWEB)

    Winebarger, Amy R.; Cirtain, Jonathan; Savage, Sabrina; Alexander, Caroline [NASA Marshall Space Flight Center, ZP 13, Huntsville, AL 35812 (United States); Golub, Leon; DeLuca, Edward [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Schuler, Timothy, E-mail: amy.r.winebarger@nasa.gov [State University of New York College at Buffalo, 1300 Elmwood Avenue, Buffalo, NY 14222 (United States)

    2014-05-20

    In the Summer of 2012, the High-resolution Coronal Imager (Hi-C) flew on board a NASA sounding rocket and collected the highest spatial resolution images ever obtained of the solar corona. One of the goals of the Hi-C flight was to characterize the substructure of the solar corona. We therefore examine how the intensity scales from AIA resolution to Hi-C resolution. For each low-resolution pixel, we calculate the standard deviation in the contributing high-resolution pixel intensities and compare that to the expected standard deviation calculated from the noise. If these numbers are approximately equal, the corona can be assumed to be smoothly varying, i.e., have no evidence of substructure in the Hi-C image to within Hi-C's ability to measure it given its throughput and readout noise. A standard deviation much larger than the noise value indicates the presence of substructure. We calculate these values for each low-resolution pixel for each frame of the Hi-C data. On average, 70% of the pixels in each Hi-C image show no evidence of substructure. The locations where substructure is prevalent is in the moss regions and in regions of sheared magnetic field. We also find that the level of substructure varies significantly over the roughly 160 s of the Hi-C data analyzed here. This result indicates that the finely structured corona is concentrated in regions of heating and is highly time dependent.

  13. DISCOVERY OF FINELY STRUCTURED DYNAMIC SOLAR CORONA OBSERVED IN THE Hi-C TELESCOPE

    International Nuclear Information System (INIS)

    In the Summer of 2012, the High-resolution Coronal Imager (Hi-C) flew on board a NASA sounding rocket and collected the highest spatial resolution images ever obtained of the solar corona. One of the goals of the Hi-C flight was to characterize the substructure of the solar corona. We therefore examine how the intensity scales from AIA resolution to Hi-C resolution. For each low-resolution pixel, we calculate the standard deviation in the contributing high-resolution pixel intensities and compare that to the expected standard deviation calculated from the noise. If these numbers are approximately equal, the corona can be assumed to be smoothly varying, i.e., have no evidence of substructure in the Hi-C image to within Hi-C's ability to measure it given its throughput and readout noise. A standard deviation much larger than the noise value indicates the presence of substructure. We calculate these values for each low-resolution pixel for each frame of the Hi-C data. On average, 70% of the pixels in each Hi-C image show no evidence of substructure. The locations where substructure is prevalent is in the moss regions and in regions of sheared magnetic field. We also find that the level of substructure varies significantly over the roughly 160 s of the Hi-C data analyzed here. This result indicates that the finely structured corona is concentrated in regions of heating and is highly time dependent

  14. Dynamical axion string, screw dislocation in Weyl semimetals and Axion insulators

    Science.gov (United States)

    You, Yi-Zhi; Cho, Gil Young; Hughes, Taylor

    We study the interplay between the geometry and axion string resulting from a chiral symmetry breaking in 3D. The chiral symmetry is spontaneously broken by charge density wave (CDW) order parameter nesting two Weyl points, which turns it into an axion insulator. The phase fluctuation of the CDW order parameter acts as a dynamical axion field coupled to electromagnetic field via θF ∧ F term. When the axion insulator is coupled with the background geometry with torsional defects, i.e. screw dislocations, there is a novel interplay between the dislocation and the dynamical axion string. First, we show that the screw dislocation traps an axial charge. This then implies that if an axion string braids with a parallel screw dislocation, there is Berry phase accumulated during the braiding procedure. In addition, the cubic coupling between the axial current and the torsion bilinear shows the Berry phase accumulated by the three-loop braiding procedure, where we braid one dislocation loop around the other dislocation loop where the both are linked by an axion string loop. We also observe a chiral magnetic effect induced by a screw dislocation in the absence of chemical potential imbalance between Weyl points.

  15. Response properties of axion insulators and Weyl semimetals driven by screw dislocations and dynamical axion strings

    Science.gov (United States)

    You, Yizhi; Cho, Gil Young; Hughes, Taylor L.

    2016-08-01

    In this paper, we investigate the theory of dynamical axion strings emerging from chiral symmetry breaking in three-dimensional Weyl semimetals. The chiral symmetry is spontaneously broken by a charge density wave (CDW) order which opens an energy gap and converts the Weyl semimetal into an axion insulator. Indeed, the phase fluctuations of the CDW order parameter act as a dynamical axion field θ (x ⃗,t ) and couple to electromagnetic field via Lθ=θ/(x ⃗,t ) 32 π2 ɛσ τ ν μFσ τFν μ. Additionally, when the axion insulator is coupled to deformations of the background geometry/strain fields via torsional defects, e.g., screw dislocations, there is interesting interplay between the crystal dislocations and dynamical axion strings. For example, the screw dislocation traps axial charge, and there is a Berry phase accumulation when an axion string (which carries axial flux) is braided with a screw dislocation. In addition, a cubic coupling between the axial current and the geometry fields is nonvanishing and indicates a Berry phase accumulation during a particular three-loop braiding procedure where a dislocation loop is braided with another dislocation and they are both threaded by an axion string. We also observe a chiral magnetic effect induced by a screw dislocation density in the absence of a nodal energy imbalance between Weyl points and describe an additional chiral geometric effect and a geometric Witten effect.

  16. Axion from Quivers in Type II Superstrings

    CERN Document Server

    Belhaj, Adil; del Moral, Maria Pilar Garcia

    2015-01-01

    We investigate a string-inspired axion extension of the standard model obtained from Type II superstrings using quiver method. In the first part, we discuss intersecting Type IIA D6-branes wrapping non trivial 3-cycles in the presence of the Peccei-Quinn symmetry U(1)$_{PQ}$. Concretely, a complex scalar field $\\phi =\\rho exp(\\frac{i\\sigma}{f_{\\sigma}})$, where $\\sigma$ is a closed string axion generates a general fermion Yukawa coupling weighted by a flavor-dependent power $n_{f}$ taking specific values. Using string theory and standard model data, we find that the corresponding axion window is in the allowed range $10^{9}GeV\\leq f_{\\sigma}\\leq 10^{12}GeV $ matching with the recent cosmological results. Then, we extend these results to the case of the hyperbolic quiver whose the moduli is related to the stringy axion using root systems of ADE Lie algebras. For the hyperbolic quiver case, we observe that the closed axion decay constant becomes disentangled from the string scale.

  17. Lattice QCD input for axion cosmology

    CERN Document Server

    Berkowitz, Evan; Rinaldi, Enrico

    2015-01-01

    One intriguing BSM particle is the QCD axion, which could simultaneously provide a solution to the Strong CP problem and account for some, if not all, of the dark matter density in the universe. This particle is a pNGB of the conjectured Peccei-Quinn (PQ) symmetry of the Standard Model. Its mass and interactions are suppressed by a heavy symmetry breaking scale, $f_a$, whose value is roughly greater than $10^{9}$ GeV (or, conversely, the axion mass, $m_a$, is roughly less than $10^4\\ \\mu \\text{eV}$). The density of axions in the universe, which cannot exceed the relic dark matter density and is a quantity of great interest in axion experiments like ADMX, is a result of the early-universe interplay between cosmological evolution and the axion mass as a function of temperature. The latter quantity is proportional to the second derivative of the QCD free energy with respect to the CP-violating phase, $\\theta$. However, this quantity is generically non-perturbative and previous calculations have only employed ins...

  18. Axion-dilaton cosmology and dark energy

    International Nuclear Information System (INIS)

    We discuss a class of flat FRW cosmological models based on D=4 axion-dilaton gravity universally coupled to cosmological background fluids. In particular, we investigate the possibility of recurrent acceleration, which was recently shown to be generically realized in a wide class of axion-dilaton models, but in absence of cosmological background fluids. We observe that, once we impose the existence of radiation - and matter - dominated earlier stages of cosmic evolution, the axion-dilaton dynamics is altered significantly with respect to the case of pure axion-dilaton gravity. During the matter dominated epoch the scalar fields remain either frozen, due to the large expansion rate, or enter a cosmological scaling regime. In both cases, oscillations of the effective equation of state around the acceleration boundary value are impossible. Models which enter an oscillatory stage in the low redshift regime, on the other hand, are disfavored by observations. We also comment on the viability of the axion-dilaton system as a candidate for dynamical dark energy. In a certain subclass of models, an intermediate scaling regime is succeeded by eternal acceleration. We also briefly discuss the issue of dependence on initial conditions. (orig.)

  19. Coupled Boltzmann computation of mixed axion neutralino dark matter in the SUSY DFSZ axion model

    International Nuclear Information System (INIS)

    The supersymmetrized DFSZ axion model is highly motivated not only because it offers solutions to both the gauge hierarchy and strong CP problems, but also because it provides a solution to the SUSY μ-problem which naturally allows for a Little Hierarchy. We compute the expected mixed axion-neutralino dark matter abundance for the SUSY DFSZ axion model in two benchmark cases—a natural SUSY model with a standard neutralino underabundance (SUA) and an mSUGRA/CMSSM model with a standard overabundance (SOA). Our computation implements coupled Boltzmann equations which track the radiation density along with neutralino, axion, axion CO (produced via coherent oscillations), saxion, saxion CO, axino and gravitino densities. In the SUSY DFSZ model, axions, axinos and saxions go through the process of freeze-in—in contrast to freeze-out or out-of-equilibrium production as in the SUSY KSVZ model—resulting in thermal yields which are largely independent of the re-heat temperature. We find the SUA case with suppressed saxion-axion couplings (ξ=0) only admits solutions for PQ breaking scale fa∼< 6× 1012 GeV where the bulk of parameter space tends to be axion-dominated. For SUA with allowed saxion-axion couplings (ξ =1), then fa values up to ∼ 1014 GeV are allowed. For the SOA case, almost all of SUSY DFSZ parameter space is disallowed by a combination of overproduction of dark matter, overproduction of dark radiation or violation of BBN constraints. An exception occurs at very large fa∼ 1015–1016 GeV where large entropy dilution from CO-produced saxions leads to allowed models

  20. Flares as fingerprints of inner solar darkness

    CERN Document Server

    Zioutas, K; Semertzidis, Y; Papaevangelou, T

    2008-01-01

    Xray flares and other much weaker solar brightenings have their roots in magnetized regions. Until now, such a solar Xray emission had been discarded as potential axion signature, as it did not match the expectations of the standard axion model: signal must appear exclusively near disk centre and its analog spectrum must peak at 4.2 keV. We argue how to reconcile model with observation. This work is in support of previous claims about the axion origin of specific solar observations.

  1. Resolving the Fan-Spine Reconnection Geometry of a Small-Scale Chromospheric Jet Event with the New Solar Telescope

    CERN Document Server

    Zeng, Zhicheng; Ji, Haisheng; Goode, Philip R; Cao, Wenda

    2016-01-01

    Jets present ubiquitously in both quiet and active regions on the Sun. They are widely believed to be driven by magnetic reconnection. A fan-spine structure has been frequently reported in some coronal jets and flares, regarded as a signature of ongoing magnetic reconnection in a topology consisting of a magnetic null connected by a fan-like separatrix surface and a spine. However, for small-scale chromospheric jets, clear evidence of such structures is rather rare, although they are implied in earlier works that show an inverted-Y-shaped feature. Here we report high-resolution (0$"$.16) observations of a small-scale chromospheric jet obtained by the New Solar Telescope (NST) using 10830~{\\AA} filtergrams. Bi-directional flows were observed across the separatrix regions in the 10830~\\AA{} images, suggesting that the jet was produced due to magnetic reconnection. At the base of the jet, a fan-spine structure was clearly resolved by the NST, including the spine and the fan-like surface, as well as the loops bef...

  2. End-to-end simulations of the Visible Tunable Filter for the Daniel K. Inouye Solar Telescope

    CERN Document Server

    Schmidt, Wolfgang; Ellwarth, Monika; Baumgartner, Jörg; Bell, Alexander; Fischer, Andreas; Halbgewachs, Clemens; Heidecke, Frank; Kentischer, Thomas; von der Lühe, Oskar; Scheiffelen, Thomas; Sigwarth, Michael

    2016-01-01

    The Visible Tunable Filter (VTF) is a narrowband tunable filter system for imaging spectroscopy and spectropolarimetry based. The instrument will be one of the first-light instruments of the Daniel K. Inouye Solar Telescope that is currently under construction on Maui (Hawaii). The VTF is being developed by the Kiepenheuer Institut fuer Sonnenphysik in Freiburg as a German contribution to the DKIST. We perform end-to-end simulations of spectropolarimetric observations with the VTF to verify the science requirements of the instrument. The instrument is simulated with two Etalons, and with a single Etalon. The clear aperture of the Etalons is 250 mm, corresponding to a field of view with a diameter of 60 arcsec in the sky (42,000 km on the Sun). To model the large-scale figure errors we employ low-order Zernike polynomials (power and spherical aberration) with amplitudes of 2.5 nm RMS. We use an ideal polarization modulator with equal modulation coefficients of 3-1/2 for the polarization modulation We synthesiz...

  3. Dynamical Axion String, Torsion Defects in Axion Insulator and Weyl Semimetals

    CERN Document Server

    You, Yizhi; Hughes, Taylor L

    2016-01-01

    In this paper, we investigate the theory of dynamical axion string emerging from chiral symmetry breaking in three-dimensional Weyl semimetals. The chiral symmetry is spontaneously broken by a charge density wave (CDW) order which opens an energy gap and converts the Weyl semimetal into an axion insulator. Indeed, the phase fluctuations of the CDW order parameter act as a dynamical axion field $\\theta({\\vec{x}},t)$ and couples to electromagnetic field via $\\mathcal{L}_{\\theta}=\\frac{\\theta(\\vec{x},t)}{32\\pi^2} \\epsilon^{\\sigma\\tau\

  4. Measuring a piecewise constant axion field in classical electrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Obukhov, Yuri N. [Institute for Theoretical Physics, University of Cologne, 50923 Cologne (Germany)]. E-mail: yo@thp.uni-koeln.de; Hehl, Friedrich W. [Institute for Theoretical Physics, University of Cologne, 50923 Cologne (Germany)

    2005-06-27

    In order to settle the problem of the 'Post constraint' in material media, we consider the propagation of a plane electromagnetic wave in a medium with a piecewise constant axion field. Although a constant axion field does not affect the wave propagation in a homogeneous medium, we show that the reflection and transmission of a wave at an interface between the two media is sensitive to the difference of the axion values. This observation can be used to determine experimentally the axion piece in matter despite the fact that a constant axion value does not contribute to the Maxwell equations.

  5. Measuring a piecewise constant axion field in classical electrodynamics

    CERN Document Server

    Obukhov, Yu N; Obukhov, Yuri N.; Hehl, Friedrich W.

    2005-01-01

    In order to settle the problem of the "Post constraint" in material media, we consider the propagation of a plane electromagnetic wave in a medium with a piecewise constant axion field. Although a constant axion field does not affect the wave propagation in a homogeneous medium, we show that the reflection and transmission of a wave at an interface between the two media is sensitive to the difference of the axion values. This observation can be used to determine experimentally the axion piece in matter despite the fact that a constant axion value does not contribute to the Maxwell equations.

  6. Constraining the Axion Portal with B -> K l+ l-

    CERN Document Server

    Freytsis, Marat; Thaler, Jesse

    2009-01-01

    We investigate the bounds on axion-like states from flavor-changing neutral current b->s decays, assuming the axion couples to the standard model through mixing with the Higgs sector. Such GeV-scale axions have received renewed attention in connection with observed cosmic ray excesses. We find that existing B->K l+ l- data impose stringent bounds on the axion decay constant in the multi-TeV range, relevant for constraining the "axion portal" model of dark matter. Such bounds also constrain light Higgs scenarios in the NMSSM. These bounds can be improved by dedicated searches in B-factory data and at LHCb.

  7. SQUID-based Resonant Detection of Axion Dark Matter

    CERN Document Server

    Popov, Vladimir

    2014-01-01

    A new method for searching for Dark Matter axions is proposed. It is shown that a two-contact SQUID can detect oscillating magnetic perturbations induced by the axions in a strong inhomogeneous magnetic field. A resonant signal is a steplike response in the SQUID current-voltage characteristic at a voltage corresponding to the axion mass with a height depending on the axion energy density near the Earth. The proposed experimental technique appears to be sensitive to the axions with masses $m_a\\lesssim 10^{-4}$ eV, which is well-motivated by current researches both in cosmology and in particle physics.

  8. Resonance detection of dark matter axions using a DC SQUID

    Science.gov (United States)

    Popov, V. A.

    2016-02-01

    A method for detecting dark matter axions in which a dc SQUID serves as a detector is proposed. The SQUID is shown to be able to detect the magnetic field perturbations induced by its interaction with axions. The resonance signal appears as a current step in the SQUID current-voltage characteristic. The voltage of the step corresponds to the axion mass, while its height depends on the axion energy density in near-Earth space. The proposed method is aimed at detecting axions with masses m a ≲ 10-4 eV, which are of interest for both cosmology and particle physics.

  9. Discrete Abelian gauge symmetries and axions

    CERN Document Server

    Honecker, Gabriele

    2015-01-01

    We combine two popular extensions of beyond the Standard Model physics within the framework of intersecting D6-brane models: discrete Zn symmetries and Peccei-Quinn axions. The underlying natural connection between both extensions is formed by the presence of massive U(1) gauge symmetries in D-brane model building. Global intersecting D6-brane models on toroidal orbifolds of the type T6/Z2N and T6/Z2xZ2M with discrete torsion offer excellent playgrounds for realizing these extensions. A generation-dependent Z2 symmetry is identified in a global Pati-Salam model, while global left-right symmetric models give rise to supersymmetric realizations of the DFSZ axion model. In one class of the latter models, the axion as well as Standard Model particles carry a non-trivial Z3 charge.

  10. A 750 GeV QCD axion

    CERN Document Server

    Dimopoulos, Savas; Huang, Junwu; Marques-Tavares, Gustavo

    2016-01-01

    We present a model where the 750 GeV resonance plays a fundamental role as the QCD axion. Conformal dynamics and strong CP considerations account for the coincidence of the weak scale, the axion mass, and the scale of spontaneous PQ breaking. A benchmark minimal model predicts just a pseudoscalar color octet at 1 TeV and heavier colored states carrying a new strong force accessible at future hadron colliders. This model is predictive as after fixing the 750 GeV mass and the diphoton rate, there are only two free choices of hypercharge assignment which completely determine the mass, decay modes and widths of the axion and the color octet.

  11. Nonminimal Einstein-Maxwell-Vlasov-axion model

    CERN Document Server

    Balakin, Alexander B; Zayats, Alexei E

    2014-01-01

    We establish a new self-consistent system of equations accounting for a nonminimal coupling of the cooperative gravitational, electromagnetic and pseudoscalar (axion) fields in a multi-component relativistic plasma. The axionic extension of the nonminimal Einstein-Maxwell-Vlasov theory is based on two consistent procedures. First, we use the Lagrange formalism to obtain nonminimal equations for the gravitational, electromagnetic and pseudoscalar fields with the additional sources generated in plasma. Second, we use the Vlasov version of the relativistic kinetic theory of the plasma, guided by the cooperative macroscopic electromagnetic, gravitational and axionic fields, to describe adequately the response of the plasma on the variations of these fields. In order to show the self-consistency of this approach we check directly the compatibility conditions for the master equations for the cooperative fields. Using these compatibility conditions we reconstruct the ponderomotive force, which acts on the plasma par...

  12. Discrete Abelian gauge symmetries and axions

    Science.gov (United States)

    Honecker, Gabriele; Staessens, Wieland

    2015-07-01

    We combine two popular extensions of beyond the Standard Model physics within the framework of intersecting D6-brane models: discrete ℤn symmetries and Peccei-Quinn axions. The underlying natural connection between both extensions is formed by the presence of massive U(1) gauge symmetries in D-brane model building. Global intersecting D6-brane models on toroidal orbifolds of the type T6/ℤ2N and T6/ℤ2 × ℤ2M with discrete torsion offer excellent playgrounds for realizing these extensions. A generation-dependent ℤ2 symmetry is identified in a global Pati-Salam model, while global left-right symmetric models give rise to supersymmetric realizations of the DFSZ axion model. In one class of the latter models, the axion as well as Standard Model particles carry a non-trivial ℤ3 charge.

  13. Solitonic axion condensates modeling dark matter halos

    Energy Technology Data Exchange (ETDEWEB)

    Castañeda Valle, David, E-mail: casvada@gmail.com; Mielke, Eckehard W., E-mail: ekke@xanum.uam.mx

    2013-09-15

    Instead of fluid type dark matter (DM), axion-like scalar fields with a periodic self-interaction or some truncations of it are analyzed as a model of galaxy halos. It is probed if such cold Bose–Einstein type condensates could provide a viable soliton type interpretation of the DM ‘bullets’ observed by means of gravitational lensing in merging galaxy clusters. We study solitary waves for two self-interacting potentials in the relativistic Klein–Gordon equation, mainly in lower dimensions, and visualize the approximately shape-invariant collisions of two ‘lump’ type solitons. -- Highlights: •An axion model of dark matter is considered. •Collision of axion type solitons are studied in a two dimensional toy model. •Relations to dark matter collisions in galaxy clusters are proposed.

  14. Astrophysical axion bounds diminished by screening effects

    International Nuclear Information System (INIS)

    ''Invisible axions'' could be produced in stellar interiors through Compton- and Primakoff-type photoproduction and through bremsstrahlung processes. We point out that in a plasma screening effects lead to important reductions of these emission rates. Limits on the axion mass and interaction strength are thereby relaxed to values less restrictive than limits previously thought to be firm. For the case of the Sun the Primakoff rate is reduced by two orders of magnitude. This process is the dominant emission mechanism for Kim-Shifman-Vainshtein-Zakharov- (KSVZ) type axions which do not couple directly to electrons. The mass limit is then relaxed by an order of magnitude to m/sub a/2β of the model equals unity. Our results can be easily translated to other hypothetical pseudoscalar particles if they are light compared with typical stellar temperatures

  15. Axion inflation in F-theory

    International Nuclear Information System (INIS)

    We study the dynamics of axion-like fields in F-theory and suggest that they can serve as inflatons in models of natural inflation. The axions arise from harmonic three-forms on the F-theory compactification space and parameterize a complex torus that varies over the geometric moduli space. In particular, this implies that the axion decay constants depend on the complex structure moduli that can be fixed by background fluxes. This might allow tuning them to be super-Planckian in a controlled way and allow for interesting single field inflationary models. We argue that this requires a localization of the three-forms near regions of strong string coupling, analogously to the reasoning that GUT physics requires the use of F-theory. These models can admit a tensor to scalar ratio r>0.1

  16. A Broadband Approach to Axion Dark Matter Detection

    CERN Document Server

    Kahn, Yonatan; Thaler, Jesse

    2016-01-01

    When ultralight axion dark matter encounters a static magnetic field, it sources an effective electric current that follows the magnetic field lines and oscillates at the axion Compton frequency. We propose a new experiment to detect this axion effective current. In the presence of axion dark matter, a large toroidal magnet will act like an oscillating current ring, whose induced magnetic flux can be measured by an external pickup loop inductively coupled to a SQUID magnetometer. We consider both resonant and broadband readout circuits and show that a broadband approach has advantages at small axion masses. We estimate the reach of this design, taking into account the irreducible sources of noise, and demonstrate potential sensitivity to axion dark matter with masses in the range of 10^{-13} eV to 10^{-6} eV, particularly the QCD axion with a GUT-scale decay constant.

  17. CAST constraints on the axion-electron coupling

    CERN Document Server

    Barth, K; Beltran, B; Bräuninger, H; Carmona, J M; Collar, J I; Dafni, T; Davenport, M; Di Lella, L; Eleftheriadis, C; Englhauser, J; Fanourakis, G; Ferrer-Ribas, E; Fischer, H; Franz, J; Friedrich, P; Galan, J; Garcia, J A; Geralis, T; Giomataris, I; Gninenko, S; Gomez, H; Hasinoff, M D; Heinsius, F H; Hoffmann, D H H; Irastorza, I G; Jacoby, J; Jakovcic, K; Kang, D; Königsmann, K; Kotthaus, R; Kousouris, K; Krcmar, M; Kuster, M; Lakic, B; Liolios, A; Ljubicic, A; Lutz, G; Luzon, G; Miller, D W; Papaevangelou, T; Pivovaroff, M J; Raffelt, G; Redondo, J; Riege, H; Rodriguez, A; Ruz, J; Savvidis, I; Semertzidis, Y; Stewart, L; Van Bibber, K; Vieira, J D; Villar, J A; Vogel, J K; Walckiers, L; Zioutas, K

    2013-01-01

    In non-hadronic axion models, which have a tree-level axion-electron interaction, the Sun produces a strong axion flux by bremsstrahlung, Compton scattering, and axio-recombination, the "BCA processes." Based on a new calculation of this flux, including for the first time axio-recombination, we derive limits on the axion-electron Yukawa coupling g_ae and axion-photon interaction strength g_ag using the CAST phase-I data (vacuum phase). For m_a < 10 meV/c2 we find g_ag x g_ae< 8.1 x 10^-23 GeV^-1 at 95% CL. We stress that a next-generation axion helioscope such as the proposed IAXO could push this sensitivity into a range beyond stellar energy-loss limits and test the hypothesis that white-dwarf cooling is dominated by axion emission.

  18. Cosmological Perturbations of Axion with a Dynamical Decay Constant

    CERN Document Server

    Kobayashi, Takeshi

    2016-01-01

    A QCD axion with a time-dependent decay constant has been known to be able to accommodate high-scale inflation without producing topological defects or too large isocurvature perturbations on CMB scales. We point out that a dynamical decay constant also has the effect of enhancing the small-scale axion isocurvature perturbations. The enhanced axion perturbations can even exceed the periodicity of the axion potential, and thus lead to the formation of axionic domain walls. Unlike the well-studied axionic walls, the walls produced from the enhanced perturbations are not bounded by cosmic strings, and thus would overclose the universe independently of the number of degenerate vacua along the axion potential.

  19. Drifting oscillations in axion monodromy

    International Nuclear Information System (INIS)

    We study the pattern of oscillations in the primordial power spectrum in axion monodromy inflation, accounting for drifts in the oscillation period that can be important for comparing to cosmological data. In these models the potential energy has a monomial form over a super-Planckian field range, with superimposed modulations whose size is model-dependent. The amplitude and frequency of the modulations are set by the expectation values of moduli fields. We show that during the course of inflation, the diminishing energy density can induce slow adjustments of the moduli, changing the modulations. We provide templates capturing the effects of drifting moduli, as well as drifts arising in effective field theory models based on softly broken discrete shift symmetries, and we estimate the precision required to detect a drifting period. A non-drifting template suffices over a wide range of parameters, but for the highest frequencies of interest, or for sufficiently strong drift, it is necessary to include parameters characterizing the change in frequency over the e-folds visible in the CMB. We use these templates to perform a preliminary search for drifting oscillations in a part of the parameter space in the Planck nominal mission data.

  20. Universal constraints on axions from inflation

    DEFF Research Database (Denmark)

    Ferreira, R. Z.; Sloth, M. S.

    2014-01-01

    perturbations through this mechanism, larger than the vacuum ones, without violating the observational constraints unless we combine this mechanism with a curvaton or if the sigma field becomes heavy and decays during inflation. Even in this last case there are non-trivial constraints coming from the slow......-roll evolution of the curvature perturbation on super horizon scales which should be taken into account. We also comment on implications for inflationary models where axions play an important role as, for example, models of natural inflation where more than one axion are included and models where the curvaton is...

  1. Non-Gaussianity from Axion Monodromy Inflation

    DEFF Research Database (Denmark)

    Hannestad, Steen; Haugboelle, Troels; R. Jarnhus, Philip;

    2010-01-01

    We study the primordial non-Gaussinity predicted from simple models of inflation with a linear potential and superimposed oscillations. This generic form of the potential is predicted by the axion monodromy inflation model, that has recently been proposed as a possible realization of chaotic...... inflation in string theory, where the monodromy from wrapped branes extends the range of the closed string axions to beyond the Planck scale. The superimposed oscillations in the potential can lead to new signatures in the CMB spectrum and bispectrum. In particular the bispectrum will have a new distinct...

  2. ATST telescope mount: telescope of machine tool

    Science.gov (United States)

    Jeffers, Paul; Stolz, Günter; Bonomi, Giovanni; Dreyer, Oliver; Kärcher, Hans

    2012-09-01

    The Advanced Technology Solar Telescope (ATST) will be the largest solar telescope in the world, and will be able to provide the sharpest views ever taken of the solar surface. The telescope has a 4m aperture primary mirror, however due to the off axis nature of the optical layout, the telescope mount has proportions similar to an 8 meter class telescope. The technology normally used in this class of telescope is well understood in the telescope community and has been successfully implemented in numerous projects. The world of large machine tools has developed in a separate realm with similar levels of performance requirement but different boundary conditions. In addition the competitive nature of private industry has encouraged development and usage of more cost effective solutions both in initial capital cost and thru-life operating cost. Telescope mounts move relatively slowly with requirements for high stability under external environmental influences such as wind buffeting. Large machine tools operate under high speed requirements coupled with high application of force through the machine but with little or no external environmental influences. The benefits of these parallel development paths and the ATST system requirements are being combined in the ATST Telescope Mount Assembly (TMA). The process of balancing the system requirements with new technologies is based on the experience of the ATST project team, Ingersoll Machine Tools who are the main contractor for the TMA and MT Mechatronics who are their design subcontractors. This paper highlights a number of these proven technologies from the commercially driven machine tool world that are being introduced to the TMA design. Also the challenges of integrating and ensuring that the differences in application requirements are accounted for in the design are discussed.

  3. Axion Dark Matter Detection with Cold Molecules

    CERN Document Server

    Graham, Peter W

    2011-01-01

    Current techniques cannot detect axion dark matter over much of its parameter space, particularly in the theoretically well-motivated region where the axion decay constant f_a lies near the GUT and Planck scales. We suggest a novel experimental method to search for QCD axion dark matter in this region. The axion field oscillates at a frequency equal to its mass when it is a component of dark matter. These oscillations induce time varying CP-odd nuclear moments, such as electric dipole and Schiff moments. The coupling between internal atomic fields and these nuclear moments gives rise to time varying shifts to atomic energy levels. These effects can be enhanced by using elements with large Schiff moments such as the light Actinides, and states with large spontaneous parity violation, such as molecules in a background electric field. The energy level shift in such a molecule can be ~ 10^-24 eV or larger. While challenging, this energy shift may be observable in a molecular clock configuration with technology pr...

  4. Axion models with high scale inflation

    Science.gov (United States)

    Moroi, Takeo; Mukaida, Kyohei; Nakayama, Kazunori; Takimoto, Masahiro

    2014-11-01

    We revisit the cosmological aspects of axion models. In the high-scale inflation scenario, the Peccei-Quinn (PQ) symmetry is likely to be restored during/after inflation. If the curvature of the PQ scalar potential at the origin is smaller than its vacuum expectation value; for instance in a class of SUSY axion models, thermal inflation happens before the radial component of the PQ scalar (saxion) relaxes into the global minimum of the potential and the decay of saxion coherent oscillation would produce too much axion dark radiation. In this paper, we study how to avoid the overproduction of axion dark radiation with some concrete examples. We show that, by taking account of the finite-temperature dissipation effect appropriately, the overproduction constraint can be relaxed since the PQ scalar can take part in the thermal plasma again even after the PQ phase transition. We also show that it can be further relaxed owing to the late time decay of another heavy CP-odd scalar, if it is present.

  5. Axion Models with High Scale Inflation

    CERN Document Server

    Moroi, Takeo; Nakayama, Kazunori; Takimoto, Masahiro

    2014-01-01

    We revisit the cosmological aspects of axion models. In the high-scale inflation scenario, the Peccei-Quinn (PQ) symmetry is likely to be restored during/after inflation. If the curvature of the PQ scalar potential at the origin is smaller than its vacuum expectation value; for instance in a class of SUSY axion models, thermal inflation happens before the radial component of the PQ scalar (saxion) relaxes into the global minimum of the potential and the decay of saxion coherent oscillation would produce too much axion dark radiation. In this paper, we study how to avoid the overproduction of axion dark radiation with some concrete examples. We show that, by taking account of the finite-temperature dissipation effect appropriately, the overproduction constraint can be relaxed since the PQ scalar can take part in the thermal plasma again even after the PQ phase transition. We also show that it can be further relaxed owing to the late time decay of another heavy CP-odd scalar, if it is present.

  6. Review of dark-matter axion experiments

    Energy Technology Data Exchange (ETDEWEB)

    van Bibber, K; Kinion, D

    2000-08-30

    We review the status of two ongoing large-scale searches for axions which may constitute the dark matter of our Milky Way halo. The experiments are based on the microwave cavity technique proposed by Sikivie, and marks a 'second-generation' to the original experiments performed by the Rochester-Brookhaven-Fermilab collaboration, and the University of Florida group.

  7. Particle physics footprints of the invisible axion

    International Nuclear Information System (INIS)

    I discuss some particle physics expectations of a natural class of invisible axion models. These models require the presence of charged and neutral spin zero bosons of Fermi scale masses. Indeed, such excitations appear to be telltale signals for almost all viable cold dark matter scenarios. (orig.)

  8. Cavity Microwave Searches for Cosmological Axions

    Energy Technology Data Exchange (ETDEWEB)

    Carosi, G; van Bibber, K

    2007-01-22

    This chapter will cover the search for dark matter axions based on microwave cavity experiments proposed by Pierre Sikivie. We will start with a brief overview of halo dark matter and the axion as a candidate. The principle of resonant conversion of axions in an external magnetic field will be described as well as practical considerations in optimizing the experiment as a signal-to-noise problem. A major focus of this chapter will be the two complementary strategies for ultra-low noise detection of the microwave photons--the 'photon-as-wave' approach (i.e. conventional heterojunction amplifiers and soon to be quantum-limited SQUID devices), and 'photon-as-particle' (i.e. Rydberg-atom single-quantum detection). Experimental results will be presented; these experiments have already reached well into the range of sensitivity to exclude plausible axion models, for limited ranges of mass. The section will conclude with a discussion of future plans and challenges for the microwave cavity experiment.

  9. Heavy axion in asymptotically safe QCD

    CERN Document Server

    Kobakhidze, Archil

    2016-01-01

    Assuming QCD exhibits an interacting fixed-point behaviour in the ultraviolet regime, I argue that the axion can be substantially heavier than in the conventional case of asymptotically free QCD due to the enhanced contribution of small size instantons to its mass.

  10. Small Instanton Contribution to the Axion Potential in Supersymmetric Models

    OpenAIRE

    Choi, Kiwoon; Kim, Hyungdo

    1998-01-01

    Small size QCD instantons may spoil the axion solution to the strong CP problem if QCD is not asymptotically free at high energy scales. We examine this issue in supersymmetric models using a manifestly supersymmetric scheme to compute the axion potential induced by small size instantons. Applying this scheme for a class of illustrative models, it is found that the resulting high energy axion potential is highly model-dependent, but suppressed by more powers of the soft supersymmetry breaking...

  11. Axion oscillations and the quark-hadron phase transition

    International Nuclear Information System (INIS)

    We consider the possibility that the quark-hadron phase transition occurs when the axion field passes through the minimum of its potential during its oscillation cycle. If this were to occur, the axion field would gain no energy from the associated increase in mass thus permitting the cosmological bound on the axion decay constant to be raised. However, we find that the probability of this happening is small. (orig.)

  12. Accelerating dark-matter axion searches with quantum measurement technology

    OpenAIRE

    Zheng, Huaixiu; Silveri, Matti; Brierley, R. T.; Girvin, S. M.; Lehnert, K. W.

    2016-01-01

    The axion particle, a consequence of an elegant hypothesis that resolves the strong-CP problem of quantum chromodynamics, is a plausible origin for cosmological dark matter. In searches for axionic dark matter that detect the conversion of axions to microwave photons, the quantum noise associated with microwave vacuum fluctuations will soon limit the rate at which parameter space is searched. Here we show that this noise can be partially overcome either by squeezing the quantum vacuum using r...

  13. The paradox of axions surviving primordial magnetic fields

    CERN Document Server

    Ahonen, J; Raffelt, G G; Ahonen, Jarkko; Enqvist, Kari; Raffelt, Georg

    1995-01-01

    In the presence of primordial magnetic fields the oscillating cosmic axion field drives an oscillating electric field. The ensuing dissipation of axions is found to be inversely proportional to the conductivity of the primordial plasma. This counterintuitive result is essentially equivalent to ``Zeno's paradox'' or the ``watched-pot effect'' of quantum mechanics. It implies that the standard predictions of the cosmic axion density remain unaltered even if primordial magnetic fields are strong.

  14. Thermal axion constraints in non-standard thermal histories

    OpenAIRE

    Grin, Daniel; Smith, Tristan; Kamionkowski, Marc

    2010-01-01

    There is no direct evidence for radiation domination prior to big-bang nucleosynthesis, and so it is useful to consider how constraints to thermally-produced axions change in non-standard thermal histories. In the low-temperature-reheating scenario, radiation domination begins at temperatures as low as 1 MeV, and is preceded by significant entropy generation. Axion abundances are then suppressed, and cosmological limits to axions are significantly loosened. In a kination scenario, a more mode...

  15. Optical observations of comet 67P/Churyumov-Gerasimenko with the Nordic Optical Telescope. Comet activity before the solar conjunction

    Science.gov (United States)

    Zaprudin, B.; Lehto, H. J.; Nilsson, K.; Pursimo, T.; Somero, A.; Snodgrass, C.; Schulz, R.

    2015-11-01

    Context. 67P/Churyumov-Gerasimenko (67P) is a short-period Jupiter-family comet that was chosen as a target for the Rosetta mission by the European Space Agency (ESA). Monitoring of 67P with the Nordic Optical Telescope (NOT; La Palma, Spain) intends to aid this mission by providing ground-based reference information about the overall activity of the target and its astrometric position before the rendezvous. One motivation for our observations was to monitor sudden major increases in activity because they might have affected the Rosetta mission planning. None were observed. Ground-based photometric observations register the global activity of the comet, while the Rosetta spacecraft mostly measures local events. These data combined can lead to new insights into the comet behavior. Aims: The aim of this work is to perform the photometric and the astrometric monitoring of comet 67P with the NOT and to compare the results with the latest predictions for its position and activity. A new method of fitting extended-source components to the target surface brightness distribution was developed and applied to the data to estimate the size and contribution of the coma to the total brightness of the target. Methods: Comet 67P was monitored by the NOT in service mode during the period between 12.5.2013 and 11.11.2014. The very first observations were performed in the V band alone, but in the latest observations, the R band was used as well to estimate the color and nature of activity of the target. We applied a new method for estimating the coma size by deconvolving the point spread function profile from the image, which used Markov chain Monte Carlo and Bayesian statistics. This method will also be used for coma size estimations in further observations after the solar conjunction of 67P. Results: Photometric magnitudes in two colors were monitored during the period of observations. At the end of April 2014, the beginning of activity was observed. In late September 2014, a

  16. Natural inflation with multiple sub-Planckian axions

    OpenAIRE

    Choi, Kiwoon; Kim, Hyungjin; Yun, Seokhoon

    2014-01-01

    We extend the Kim-Nilles-Peloso (KNP) alignment mechanism for natural inflation to models with $N>2$ axions, which obtains a super-Planckian effective axion decay constant $f_{\\textrm{eff}}\\gg M_{Pl}$ through an alignment of the anomaly coefficients of multiple axions having sub-Planckian fundamental decay constants $f_0\\ll M_{Pl}$. The original version of the KNP mechanism realized with two axions requires that some of the anomaly coefficients should be of the order of $f_{\\textrm{eff}}/f_0$...

  17. Constraining the Axion Portal with B -> K l+ l-

    OpenAIRE

    Freytsis, Marat; Ligeti, Zoltan; Thaler, Jesse

    2009-01-01

    We investigate the bounds on axionlike states from flavor-changing neutral current b->s decays, assuming the axion couples to the standard model through mixing with the Higgs sector. Such GeV-scale axions have received renewed attention in connection with observed cosmic ray excesses. We find that existing B->K l+ l- data impose stringent bounds on the axion decay constant in the multi-TeV range, relevant for constraining the "axion portal" model of dark matter. Such bounds also constrain lig...

  18. Future cosmological sensitivity for hot dark matter axions

    OpenAIRE

    Archidiacono, Maria; Basse, Tobias; Hamann, Jan; Hannestad, Steen; Raffelt, Georg; Wong, Yvonne Y.Y

    2015-01-01

    We study the potential of a future, large-volume photometric survey to constrain the axion mass $m_a$ in the hot dark matter limit. Future surveys such as Euclid will have significantly more constraining power than current observations for hot dark matter. Nonetheless, the lowest accessible axion masses are limited by the fact that axions lighter than $\\\\sim 0.15$ eV decouple before the QCD epoch, assumed here to occur at a temperature $T_{\\\\rm QCD} \\\\sim 170$ MeV; this leaves an axion popula...

  19. An improved cosmological bound on the thermal axion mass

    OpenAIRE

    Melchiorri, Alessandro; Mena Requejo, Olga; Slosar, Anze

    2007-01-01

    Relic thermal axions could play the role of an extra hot dark matter component in cosmological structure formation theories. By combining the most recent observational data we improve previous cosmological bounds on the axion mass m(a) in the so-called hadronic axion window. We obtain a limit on the axion mass m(a)< 0.42 eV at the 95% C.L. (m(a)< 0.72 eV at the 99% C.L.). A novel aspect of the analysis presented here is the inclusion of massive neutrinos and how they may affect the bound on t...

  20. Discovering the QCD Axion with Black Holes and Gravitational Waves

    CERN Document Server

    Arvanitaki, Asimina; Huang, Xinlu

    2014-01-01

    Advanced LIGO will be the first experiment to detect gravitational waves. Through superradiance of stellar black holes, it may also be the first experiment to discover the QCD axion with decay constant above the GUT scale. When an axion's Compton wavelength is comparable to the size of a black hole, the axion binds to the black hole, forming a "gravitational atom." Through the superradiance process, the number of axions occupying the bound levels grows exponentially, extracting energy and angular momentum from the black hole. Axions transitioning between levels of the gravitational atom and axions annihilating to gravitons produce observable gravitational wave signals. The signals are long-lasting, monochromatic, and can be distinguished from ordinary astrophysical sources. We estimate O(1) transition events at aLIGO for an axion between 10^-11 and 10^-10 eV and up to 1000 annihilation events for an axion between 10^-13 and 10^-12 eV. Axion annihilations are particularly promising for much lighter masses at f...

  1. Constraining axion dark matter with Big Bang Nucleosynthesis

    International Nuclear Information System (INIS)

    We show that Big Bang Nucleosynthesis (BBN) significantly constrains axion-like dark matter. The axion acts like an oscillating QCD θ angle that redshifts in the early Universe, increasing the neutron–proton mass difference at neutron freeze-out. An axion-like particle that couples too strongly to QCD results in the underproduction of 4He during BBN and is thus excluded. The BBN bound overlaps with much of the parameter space that would be covered by proposed searches for a time-varying neutron EDM. The QCD axion does not couple strongly enough to affect BBN

  2. Constraining axion dark matter with Big Bang Nucleosynthesis

    Directory of Open Access Journals (Sweden)

    Kfir Blum

    2014-10-01

    Full Text Available We show that Big Bang Nucleosynthesis (BBN significantly constrains axion-like dark matter. The axion acts like an oscillating QCD θ angle that redshifts in the early Universe, increasing the neutron–proton mass difference at neutron freeze-out. An axion-like particle that couples too strongly to QCD results in the underproduction of He4 during BBN and is thus excluded. The BBN bound overlaps with much of the parameter space that would be covered by proposed searches for a time-varying neutron EDM. The QCD axion does not couple strongly enough to affect BBN.

  3. Axion star collisions with Neutron stars and Fast Radio Bursts

    CERN Document Server

    Raby, Stuart

    2016-01-01

    Axions may make a significant contribution to the dark matter of the universe. It has been suggested that these dark matter axions may condense into localized clumps, called "axion stars." In this paper we argue that collisions of dilute axion stars with neutron stars may be the origin of most of the observed fast radio bursts. This idea is a variation of an idea originally proposed by Iwazaki. However, instead of the surface effect of Iwazaki, we propose a perhaps stronger volume effect caused by the induced time dependent electric dipole moment of neutrons.

  4. Coupled Boltzmann computation of mixed axion neutralino dark matter in the SUSY DFSZ axion model

    CERN Document Server

    Bae, Kyu Jung; Lessa, Andre; Serce, Hasan

    2014-01-01

    The supersymmetrized DFSZ axion model is highly motivated not only because it offers solutions to both the gauge hierarchy and strong CP problems, but also because it provides a solution to the SUSY mu problem which naturally allows for a Little Hierarchy. We compute the expected mixed axion-neutralino dark matter abundance for the SUSY DFSZ axion model in two benchmark cases-- a natural SUSY model with a standard neutralino underabundance (SUA) and an mSUGRA/CMSSM model with a standard overabundance (SOA). Our computation implements coupled Boltzmann equations which track the radiation density along with neutralino, axion (produced thermally (TH) and via coherent oscillations (CO)), saxion (TH- and CO-produced), axino and gravitino densities. In the SUSY DFSZ model, axions, axinos and saxions go through the process of freeze-in-- in contrast to freeze-out or out-of-equilibrium production as in the SUSY KSVZ model-- resulting in thermal yields which are largely independent of the re-heat temperature. We find ...

  5. Mixed axion/neutralino dark matter in the SUSY DFSZ axion model

    International Nuclear Information System (INIS)

    We examine mixed axion/neutralino cold dark matter production in the SUSY DFSZ axion model where an axion superfield couples to Higgs superfields. We calculate a wide array of axino and saxion decay modes along with their decay temperatures, and thermal and non-thermal production rates. For a SUSY benchmark model with a standard underabundance (SUA) of Higgsino-like dark matter (DM), we find for the PQ scale fa∼<1012 GeV that the DM abundance is mainly comprised of axions as the saxion/axino decay occurs before the standard neutralino freeze-out and thus its abundance remains suppressed. For 1012∼1014 GeV, both neutralino dark matter and dark radiation are typically overproduced. For judicious parameter choices, these can be suppressed and the combined neutralino/axion abundance brought into accord with measured values. A SUSY benchmark model with a standard overabundance (SOA) of bino DM is also examined and typically remains excluded due at least to too great a neutralino DM abundance for fa∼<1015 GeV. For fa∼>1015 GeV and lower saxion masses, large entropy production from saxion decay can dilute all relics and the SOA model can be allowed by all constraints

  6. Minimal Models for Axion and Neutrino

    CERN Document Server

    Ahn, Y H

    2015-01-01

    The PQ mechanism resolving the strong CP problem and the seesaw mechanism explaining the smallness of neutrino masses may be related in a way that the PQ symmetry breaking scale and the seesaw scale arise from a common origin. Depending on how the PQ symmetry and the seesaw mechanism are realized, one has different predictions on the color and electromagnetic anomalies which could be tested in the future axion dark matter search experiments. Motivated by this, we construct various PQ seesaw models which are minimally extended from the (non-) supersymmetric Standard Model and thus set up different benchmark points on the axion-photon-photon coupling in comparison with the standard KSVZ and DFSZ models.

  7. Minimal models for axion and neutrino

    Science.gov (United States)

    Ahn, Y. H.; Chun, Eung Jin

    2016-01-01

    The PQ mechanism resolving the strong CP problem and the seesaw mechanism explaining the smallness of neutrino masses may be related in a way that the PQ symmetry breaking scale and the seesaw scale arise from a common origin. Depending on how the PQ symmetry and the seesaw mechanism are realized, one has different predictions on the color and electromagnetic anomalies which could be tested in the future axion dark matter search experiments. Motivated by this, we construct various PQ seesaw models which are minimally extended from the (non-) supersymmetric Standard Model and thus set up different benchmark points on the axion-photon-photon coupling in comparison with the standard KSVZ and DFSZ models.

  8. Naturalness of the invisible axion model

    International Nuclear Information System (INIS)

    We discuss the choice of parameters that is necessary to establish the enormous hierarchy between the doublet and singlet Higgs vacuum expectation values in the invisible axion model. We show that this choice is associated with an approximate symmetry of the theory, thus demonstrating that the hierarchy in this model is natural in the sense of 't Hooft. It is then shown that this choice also leads to the existence of Higgs particles with masses ∝MW, which is particularly relevant for invisible axion models featuring spontaneous CP-violation. We comment on how our conclusions are affected by the introduction of right-handed neutrinos with large Majorana masses within the context of the see-saw mechanism. (orig.)

  9. Mixed axion-wino dark matter

    Directory of Open Access Journals (Sweden)

    Kyu Jung Bae

    2015-07-01

    Full Text Available A variety of supersymmetric models give rise to a split mass spectrumcharacterized by very heavy scalars but sub-TeV gauginos, usually with awino-like LSP. Such models predict a thermally-produced underabundance ofwino-like WIMP dark matter so that non-thermal DM production mechanisms arenecessary.We examine the case where theories with a wino-like LSP are augmented by aPeccei-Quinn sector including an axion-axino-saxion supermultiplet in either theSUSY KSVZ or SUSY DFSZ models and with/without saxion decays to axions/axinos.We show allowed ranges of PQ breaking scale f_a for various cases which aregenerated by solving the necessary coupled Boltzmann equations.We also present results for a model with radiatively-driven naturalnessbut with a wino-like LSP.

  10. Relativistic axions from collapsing Bose stars

    CERN Document Server

    Levkov, D G; Tkachev, I I

    2016-01-01

    The substructures of light bosonic (axion-like) dark matter may condense into compact Bose stars. We study collapses of the critical-mass stars caused by attractive self-interaction of the axion-like particles and find that these processes proceed in an unexpected universal way. First, nonlinear self-similar evolution (similar to "wave collapse" in plasma physics) forces the particles to fall into the star center. Second, collisions in the dense center create an outgoing stream of mildly relativistic particles which carries away an essential part of the star mass. The collapse stops when the star remnant is no longer able to support the self-similar infall feeding the collisions. We shortly discuss possible astrophysical and cosmological implications of these phenomena.

  11. Large volume axionic Swiss cheese inflation

    International Nuclear Information System (INIS)

    Continuing with the ideas of (Section 4 of) [A. Misra, P. Shukla, Moduli stabilization, large-volume dS minimum without anti-D3-branes, (non-)supersymmetric black hole attractors and two-parameter Swiss cheese Calabi-Yau's, (arXiv: 0707.0105 [hep-th]), Nucl. Phys. B, in press], after inclusion of perturbative and non-perturbative α' corrections to the Kaehler potential and (D1- and D3-) instanton generated superpotential, we show the possibility of slow roll axionic inflation in the large volume limit of Swiss cheese Calabi-Yau orientifold compactifications of type IIB string theory. We also include one- and two-loop corrections to the Kaehler potential but find the same to be subdominant to the (perturbative and non-perturbative) α' corrections. The NS-NS axions provide a flat direction for slow roll inflation to proceed from a saddle point to the nearest dS minimum

  12. Axion topological field theory of topological superconductors

    OpenAIRE

    Qi, Xiao-Liang; Witten, Edward; Zhang, Shou-Cheng

    2012-01-01

    Topological superconductors are gapped superconductors with gapless and topologically robust quasiparticles propagating on the boundary. In this paper, we present a topological field theory description of three-dimensional time-reversal invariant topological superconductors. In our theory the topological superconductor is characterized by a topological coupling between the electromagnetic field and the superconducting phase fluctuation, which has the same form as the coupling of "axions" with...

  13. Multiverse Dark Matter: SUSY or Axions

    CERN Document Server

    D'Eramo, Francesco; Pappadopulo, Duccio

    2014-01-01

    The observed values of the cosmological constant {\\it and} the abundance of Dark Matter (DM) can be successfully understood, using certain measures, by imposing the anthropic requirement that density perturbations go non-linear and virialize to form halos. This requires a probability distribution favoring low amounts of DM, i.e. low values of the PQ scale $f$ for the QCD axion and low values of the superpartner mass scale $\\tilde{m}$ for LSP thermal relics. In theories with independent scanning of multiple DM components, there is a high probability for DM to be dominated by a single component. For example, with independent scanning of $f$ and $\\tilde{m}$, TeV-scale LSP DM and an axion solution to the strong CP problem are unlikely to coexist. With thermal LSP DM, the scheme allows an understanding of a Little SUSY Hierarchy with multi-TeV superpartners. Alternatively, with axion DM, PQ breaking before (after) inflation leads to $f$ typically below (below) the projected range of the current ADMX experiment of ...

  14. Axion monodromy and the weak gravity conjecture

    International Nuclear Information System (INIS)

    Axions with broken discrete shift symmetry (axion monodromy) have recently played a central role both in the discussion of inflation and the 'relaxion' approach to the hierarchy problem. We suggest a very minimalist way to constrain such models by the weak gravity conjecture for domain walls: While the electric side of the conjecture is always satisfied if the cosine-oscillations of the axion potential are sufficiently small, the magnetic side imposes a cutoff, Λ3∝mfMpl, independent of the height of these 'wiggles'. We compare our approach with the recent related proposal by Ibanez, Montero, Uranga and Valenzuela. We also discuss the non-trivial question which version, if any, of the weak gravity conjecture for domain walls should hold. In particular, we show that string compactifications with branes of different dimensions wrapped on different cycles lead to a 'geometric weak gravity conjecture' relating volumes of cycles, norms of corresponding forms and the volume of the compact space. Imposing this 'geometric conjecture', e.g. on the basis of the more widely accepted weak gravity conjecture for particles, provides at least some support for the (electric and magnetic) conjecture for domain walls.

  15. Axion monodromy and the weak gravity conjecture

    Science.gov (United States)

    Hebecker, Arthur; Rompineve, Fabrizio; Westphal, Alexander

    2016-04-01

    Axions with broken discrete shift symmetry (axion monodromy) have recently played a central role both in the discussion of inflation and the `relaxion' approach to the hierarchy problem. We suggest a very minimalist way to constrain such models by the weak gravity conjecture for domain walls: while the electric side of the conjecture is always satisfied if the cosine-oscillations of the axion potential are sufficiently small, the magnetic side imposes a cutoff, Λ3 ˜ mf M pl, independent of the height of these `wiggles'. We compare our approach with the recent related proposal by Ibanez, Montero, Uranga and Valenzuela. We also discuss the non-trivial question which version, if any, of the weak gravity conjecture for domain walls should hold. In particular, we show that string compactifications with branes of different dimensions wrapped on different cycles lead to a `geometric weak gravity conjecture' relating volumes of cycles, norms of corresponding forms and the volume of the compact space. Imposing this `geometric conjecture', e.g. on the basis of the more widely accepted weak gravity conjecture for particles, provides at least some support for the (electric and magnetic) conjecture for domain walls.

  16. Axion Monodromy and the Weak Gravity Conjecture

    CERN Document Server

    Hebecker, Arthur; Westphal, Alexander

    2015-01-01

    Axions with broken discrete shift symmetry (axion monodromy) have recently played a central role both in the discussion of inflation and the `relaxion' approach to the hierarchy problem. We suggest a very minimalist way to constrain such models by the weak gravity conjecture for domain walls: While the electric side of the conjecture is always satisfied if the cosine-oscillations of the axion potential are sufficiently small, the magnetic side imposes a cutoff, $\\Lambda^3 \\sim m f M_{pl}$, independent of the height of these `wiggles'. We compare our approach with the recent related proposal by Ibanez, Montero, Uranga and Valenzuela. We also discuss the non-trivial question which version, if any, of the weak gravity conjecture for domain walls should hold. In particular, we show that string compactifications with branes of different dimensions wrapped on different cycles lead to a `geometric weak gravity conjecture' relating volumes of cycles, norms of corresponding forms and the volume of the compact space. I...

  17. Space Telescope.

    Science.gov (United States)

    National Aeronautics and Space Administration, Huntsville, AL. George C. Marshall Space Flight Center.

    This pamphlet describes the Space Telescope, an unmanned multi-purpose telescope observatory planned for launch into orbit by the Space Shuttle in the 1980s. The unique capabilities of this telescope are detailed, the major elements of the telescope are described, and its proposed mission operations are outlined. (CS)

  18. Hubble Space Telescope

    Science.gov (United States)

    1990-02-01

    An overview of the mission of the Hubble Space Telescope, a joint project between NASA and the European Space Agency which will be used to study deep space, as well as our solar system is presented. The video contains animations depicting the Hubble Space Telescope in orbit, as well as footage of scientists at the Space Telescope Science Institute making real time observations. The images Hubble acquires will be downloaded into a database that contains images of over 19,000,0000 celestial objects called the Star Catalog.

  19. The Dutch Open Telescope

    OpenAIRE

    Rutten, R. J.; Hammerschlag, R.H.; Bettonvil, F.C.M.

    2001-01-01

    The Utrecht Open Tower Telescope, recently renamed into \\Dutch Open Telescope", is now being installed at the Roque de los Muchachos Observatory on La Palma (Fig. 1). Like THEMIS, the DOT is a solar telescope of novel design, is located at a superior site, aims at high spatial resolution, is suited to polarimetry, has been long in the making, and should start its scientic career in 1997. Unlike THEMIS, the DOT has no dome, no vacuum enclosure, no post-focus equipment, and no long-term funding.

  20. The Dutch Open Telescope

    OpenAIRE

    Rutten, R. J.; Hammerschlag, R.H.; Bettonvil, F.C.M.

    2001-01-01

    The Utrecht Open Tower Telescope, recently renamed into "Dutch Open Telescope", is now being installed at the Roque de los Muchachos Observatory on La Palma (Fig. 1). Like THEMIS, the DOT is a solar telescope of novel design, is located at a superior site, aims at high spatial resolution, is suited to polarimetry, has been long in the making, and should start its scientific career in 1997. Unlike THEMIS, the DOT has no dome, no vacuum enclosure, no post-focus equipment, and no long-term funding.

  1. Black Hole Mergers and the QCD Axion at Advanced LIGO

    CERN Document Server

    Arvanitaki, Asimina; Dimopoulos, Savas; Dubovsky, Sergei; Lasenby, Robert

    2016-01-01

    In the next few years Advanced LIGO (aLIGO) may see gravitational waves (GWs) from thousands of black hole (BH) mergers. This marks the beginning of a new precision tool for physics. Here we show how to search for new physics beyond the standard model using this tool, in particular the QCD axion in the mass range ma ~ 10^-14 to 10^-10 eV. Axions (or any bosons) in this mass range cause rapidly rotating BHs to shed their spin into a large cloud of axions in atomic Bohr orbits around the BH, through the effect of superradiance. This results in a gap in the mass vs. spin distribution of BHs when the BH size is comparable to the axion's Compton wavelength. By measuring the spin and mass of the merging objects observed at LIGO, we could verify the presence and shape of the gap in the BH distribution produced by the axion. The axion cloud can also be discovered through the GWs it radiates via axion annihilations or level transitions. A blind monochromatic GW search may reveal up to 10^5 BHs radiating through axion ...

  2. Cosmological problems with multiple axion-like fields

    International Nuclear Information System (INIS)

    Incorporating the QCD axion and simultaneously satisfying current constraints on the dark matter density and isocurvature fluctuations requires non-minimal fine-tuning of inflationary parameters or the axion misalignment angle (or both) for Peccei-Quinn symmetry-breaking scales fa > 1012 GeV. To gauge the degree of tuning in models with many axion-like fields at similar symmetry-breaking scales and masses, as may occur in string theoretic models that include a QCD axion, we introduce a figure of merit F that measures the fractional volume of allowed parameter space: the product of the slow roll parameter ε and each of the axion misalignment angles, θ0. For a single axion, F∼−11 is needed to avoid conflict with observations. We show that the fine tuning of F becomes exponentially more extreme in the case of numerous axion-like fields. Anthropic arguments are insufficient to explain the fine tuning because the bulk of the anthropically allowed parameter space is observationally ruled out by limits on the cosmic microwave background isocurvature modes. Therefore, this tuning presents a challenge to the compatibility of string-theoretic models with light axions and inflationary cosmology

  3. Cosmological problems with multiple axion-like fields

    Science.gov (United States)

    Mack, Katherine J.; Steinhardt, Paul J.

    2011-05-01

    Incorporating the QCD axion and simultaneously satisfying current constraints on the dark matter density and isocurvature fluctuations requires non-minimal fine-tuning of inflationary parameters or the axion misalignment angle (or both) for Peccei-Quinn symmetry-breaking scales fa > 1012 GeV. To gauge the degree of tuning in models with many axion-like fields at similar symmetry-breaking scales and masses, as may occur in string theoretic models that include a QCD axion, we introduce a figure of merit Script F that measures the fractional volume of allowed parameter space: the product of the slow roll parameter epsilon and each of the axion misalignment angles, θ0. For a single axion, Script Flesssim10-11 is needed to avoid conflict with observations. We show that the fine tuning of Script F becomes exponentially more extreme in the case of numerous axion-like fields. Anthropic arguments are insufficient to explain the fine tuning because the bulk of the anthropically allowed parameter space is observationally ruled out by limits on the cosmic microwave background isocurvature modes. Therefore, this tuning presents a challenge to the compatibility of string-theoretic models with light axions and inflationary cosmology.

  4. Diluting the inflationary axion fluctuation by a stronger QCD in the early Universe

    Directory of Open Access Journals (Sweden)

    Kiwoon Choi

    2015-11-01

    Full Text Available We propose a new mechanism to suppress the axion isocurvature perturbation, while producing the right amount of axion dark matter, within the framework of supersymmetric axion models with the axion scale induced by supersymmetry breaking. The mechanism involves an intermediate phase transition to generate the Higgs μ-parameter, before which the weak scale is comparable to the axion scale and the resulting stronger QCD yields an axion mass heavier than the Hubble scale over a certain period. Combined with that the Hubble-induced axion scale during the primordial inflation is well above the intermediate axion scale at present, the stronger QCD in the early Universe suppresses the axion fluctuation to be small enough even when the inflationary Hubble scale saturates the current upper bound, while generating an axion misalignment angle of order unity.

  5. Axion Haloscopes with Toroidal Geometry at CAPP/IBS

    CERN Document Server

    Ko, B R

    2016-01-01

    The present state of the art axion haloscope employs a cylindrical resonant cavity in a solenoidal field. We, the Center for Axion and Precision Physics Research (CAPP) of the Institute for Basic Science (IBS) in Korea, are also pursuing halo axion discovery using this cylindrical geometry. However, the presence of end caps of cavities increases challenges as we explore higher frequency regions for the axion at above 2 GHz. To overcome these challenges we exploit a toroidal design of cavity and magnetic field. A toroidal geometry offers several advantages, two of which are a larger volume for a given space and greatly reduced fringe fields which interfere with our preamps, in particular the planned quantum-based devices. We introduce the concept of toroidal axion haloscopes and present ongoing research activities and plans at CAPP/IBS.

  6. Mixed axion/neutralino dark matter in the SUSY DFSZ axion model

    CERN Document Server

    Bae, Kyu Jung; Chun, Eung Jin

    2013-01-01

    We examine mixed axion/neutralino cold dark matter production in the SUSY DFSZ axion model where an axion superfield couples to Higgs superfields. We calculate a wide array of axino and saxion decay modes along with their decay temperatures, and thermal and non-thermal production rates. For a SUSY benchmark model with a standard underabundance (SUA) of Higgsino-like dark matter (DM), we find for the PQ scale f_a~ 10^{14} GeV, both neutralino dark matter and dark radiation are typically overproduced. For judicious parameter choices, these can be suppressed and the combined neutralino/axion abundance brought into accord with measured values. A SUSY benchmark model with a standard overabundance (SOA) of bino DM is also examined and typically remains excluded due at least to too great a neutralino DM abundance for f_a~ 10^{15} GeV and lower saxion masses, large entropy production from saxion decay can dilute all relics and the SOA model can be allowed by all constraints.

  7. Study of Rapid Formation of a Delta Sunspot Associated with the 2012 July 2 C7.4 Flare Using High-resolution Observations of New Solar Telescope

    CERN Document Server

    Wang, Haimin; Wang, Shuo; Deng, Na; Xu, Yan; Jing, Ju; Cao, Wenda

    2013-01-01

    Rapid, irreversible changes of magnetic topology and sunspot structure associated with flares have been systematically observed in recent years. The most striking features include the increase of horizontal field at the polarity inversion line (PIL) and the co-spatial penumbral darkening. A likely explanation of the above phenomenon is the back reaction to the coronal restructuring after eruptions: a coronal mass ejection carries the upward momentum while the downward momentum compresses the field lines near the PIL. Previous studies could only use low resolution (above 1") magnetograms and white-light images. Therefore, the changes are mostly observed for X-class flares. Taking advantage of the 0.1" spatial resolution and 15s temporal cadence of the New Solar Telescope at Big Bear Solar Observatory, we report in detail the rapid formation of sunspot penumbra at the PIL associated with the C7.4 flare on 2012 July 2. It is unambiguously shown that the solar granulation pattern evolves to alternating dark and b...

  8. A New Target for Cosmic Axion Searches

    CERN Document Server

    Baumann, Daniel; Wallisch, Benjamin

    2016-01-01

    Future CMB experiments have the potential to probe the density of relativistic species at the sub-percent level. Sensitivity at this level allows light thermal relics to be detected up to arbitrarily high decoupling temperatures. Conversely, the absence of a detection would require extra light species never to have been in equilibrium with the Standard Model. In this paper, we exploit this feature to demonstrate the sensitivity of future cosmological observations to the couplings of axions to all of the Standard Model degrees of freedom. In many cases, the constraints achievable from cosmology will surpass existing bounds from laboratory experiments and astrophysical observations by orders of magnitude.

  9. Electric and magnetic energy at axion haloscopes

    CERN Document Server

    Ko, B R; Jang, W; Choi, J; Kim, D; Lee, M J; Lee, J; Won, E; Semertzidis, Y K

    2016-01-01

    We review a recent letter published in Phys. Rev. Lett. $\\textbf{116}$, 161804 (2016) of which the main argument is that the mode dependent magnetic form factors at axion haloscopes depend on the position of the cavity inside the solenoid while the corresponding electric form factors do not. We, however, find no such dependence, which is also equivalent to the statement that the electric and corresponding magnetic energy stored in the cavity modes are the same regardless of the position of the cavity inside the solenoid. Furthermore, we extend the statement to the cases satisfying $\\vec{\

  10. Solitonic axion condensates modeling dark matter halos

    Science.gov (United States)

    Castañeda Valle, David; Mielke, Eckehard W.

    2013-09-01

    Instead of fluid type dark matter (DM), axion-like scalar fields with a periodic self-interaction or some truncations of it are analyzed as a model of galaxy halos. It is probed if such cold Bose-Einstein type condensates could provide a viable soliton type interpretation of the DM 'bullets' observed by means of gravitational lensing in merging galaxy clusters. We study solitary waves for two self-interacting potentials in the relativistic Klein-Gordon equation, mainly in lower dimensions, and visualize the approximately shape-invariant collisions of two 'lump' type solitons.

  11. CAST constraints on the axion-electron coupling

    Energy Technology Data Exchange (ETDEWEB)

    Barth, K.; Davenport, M.; Lella, L. Di [European Organization for Nuclear Research (CERN), Geneve (Switzerland); Belov, A. [Institute for Nuclear Research (INR), Russian Academy of Sciences, Moscow (Russian Federation); Beltran, B.; Carmona, J.M.; Dafni, T.; Galan, J.; García, J.A. [Laboratorio de Fisica Nuclear y Altas Energias, Universidad de Zaragoza, Zaragoza (Spain); Braeuninger, H.; Englhauser, J.; Friedrich, P. [Max-Planck-Institut fuer extraterrestrische Physik, Garching (Germany); Collar, J.I. [Enrico Fermi Institute and KICP, University of Chicago, Chicago, IL (United States); Eleftheriadis, C. [Aristoteles University of Thessaloniki, Thessaloniki (Greece); Fanourakis, G.; Geralis, T. [National Center for Scientific Research ' ' Demokritos' ' , Athens (Greece); Ferrer-Ribas, E.; Giomataris, I. [IRFU, Centre d' Etudes Nucleaires de Saclay (CEA-Saclay), Gif-sur-Yvette (France); Fischer, H.; Franz, J., E-mail: Jaime.Ruz@cern.ch, E-mail: Julia.Vogel@cern.ch, E-mail: redondo@mpp.mpg.de [Albert-Ludwigs-Universitaet Freiburg, Freiburg (Germany); and others

    2013-05-01

    In non-hadronic axion models, which have a tree-level axion-electron interaction, the Sun produces a strong axion flux by bremsstrahlung, Compton scattering, and axio-recombination, the ''BCA processes.'' Based on a new calculation of this flux, including for the first time axio-recombination, we derive limits on the axion-electron Yukawa coupling g{sub ae} and axion-photon interaction strength g{sub aγ} using the CAST phase-I data (vacuum phase). For m{sub a}∼<10 meV/c{sup 2} we find g{sub aγ} g{sub ae} < 8.1 × 10{sup −23} GeV{sup −1} at 95% CL. We stress that a next-generation axion helioscope such as the proposed IAXO could push this sensitivity into a range beyond stellar energy-loss limits and test the hypothesis that white-dwarf cooling is dominated by axion emission.

  12. Neutrino telescopes

    CERN Document Server

    Carr, J

    2002-01-01

    This review presents the scientific objectives and status of Neutrino Telescope Projects. The science program of these projects covers: neutrino astronomy, dark matter searches and measurements of neutrino oscillations. The two neutrino telescopes in operation: AMANDA and BAIKAL will be described together with the ANTARES neutrino telescope being built in the Mediterranean. (18 refs).

  13. Observing the fine structure of loops through high resolution spectroscopic observations of coronal rain with the CRISP instrument at the Swedish Solar Telescope

    CERN Document Server

    Antolin, Patrick

    2011-01-01

    We present here one of the first high resolution spectroscopic observations of coronal rain, performed with the CRISP instrument at the Swedish Solar Telescope. This work constitutes the first attempt to assess the importance of coronal rain in the understanding of the coronal magnetic field in active regions. A large statistical set is obtained in which dynamics (total velocities and accelerations), shapes (lengths and widths), trajectories (angles of fall) and thermodynamic properties (temperatures) of the condensations are derived. Specifically, we find that coronal rain is composed of small and dense chromospheric cores with average widths and lengths of 310 km and 710 km respectively, average temperatures below 7000 K, displaying a broad distribution of falling speeds with an average of 70 km/s and accelerations largely below the effective gravity along loops. Through estimates of the ion-neutral coupling in the blobs we show that coronal rain acts as a tracer of the coronal magnetic field, thus supporti...

  14. Stokes imaging polarimetry using image restoration at the Swedish 1-m Solar Telescope II: A calibration strategy for Fabry-Perot based instruments

    CERN Document Server

    Schnerr, R S; van Noort, M

    2010-01-01

    Context: The combination of image restoration and a Fabry-Perot interferometer (FPI) based instrument in solar observations results in specific calibration issues. FPIs generally show variations over the field-of-view while in the image restoration process the 1-to-1 relation between pixel space and image space is lost, complicating correcting for such variations. Aims: To develop a data reduction method that takes these issues into account, and minimizes the resulting errors. Methods: By accounting for the time variations in the telescope Mueller matrix and using separate calibration data optimized for the wavefront sensing in the MOMFBD image restoration process and for the final deconvolution of the data we remove most of the calibration artifacts from the resulting data. Results: Using the presented method to reduce full Stokes data from CRISP at the SST, we find that it drastically reduces the instrumental and image restoration artifacts resulting from cavity errors, reflectivity variations and the polar...

  15. Dilution of axion dark radiation by thermal inflation

    CERN Document Server

    Hattori, Hironori; Omoto, Naoya; Seto, Osamu

    2015-01-01

    Axion in the Peccei-Quinn (PQ) mechanism provides a promising solution to the strong CP problem in the standard model of particle physics. Coherently generated PQ scalar fields could dominate the energy density in the early Universe and decay into relativistic axions, which would confront with the current dark radiation constraints. We study the possibility that a thermal inflation driven by a $U(1)$ gauged Higgs field dilutes such axions. A well motivated extra gauged $U(1)$ would be the local $B-L$ symmetry. We also discuss the implication for the case of $U(1)_{B-L}$ and available baryogenesis mechanism in such cosmology.

  16. Searching for galactic axions through magnetized media: the QUAX proposal

    OpenAIRE

    Barbieri, R.; Braggio, C.; Carugno, G.; Gallo, C. S.; Lombardi, A; Ortolan, A.; Pengo, R.; Ruoso, G.; Speake, C. C.

    2016-01-01

    We present a proposal to search for QCD axions with mass in the 100 $\\mu$eV range, assuming that they make a dominant component of dark matter. Due to the axion-electron spin coupling, their effect is equivalent to the application of an oscillating rf field with frequency and amplitude fixed by the axion mass and coupling respectively. This equivalent magnetic field would produce spin flips in a magnetic sample placed inside a static magnetic field, which determines the resonant interaction a...

  17. Constraining Axion Dark Matter with Big Bang Nucleosynthesis

    OpenAIRE

    Kfir Blum; Raffaele Tito D'Agnolo; Mariangela Lisanti; Benjamin R. Safdi

    2014-01-01

    We show that Big Bang Nucleosynthesis (BBN) significantly constrains axion-like dark matter. The axion acts like an oscillating QCD $\\theta$ angle that redshifts in the early universe, increasing the neutron-proton mass difference at neutron freeze-out. An axion-like particle that couples too strongly to QCD results in the underproduction of 4He during BBN and is thus excluded. The BBN bound overlaps with much of the parameter space that would be covered by proposed searches for time-varying ...

  18. Active galaxies may harbour wormholes if dark matter is axionic

    CERN Document Server

    Dimopoulos, Konstantinos

    2016-01-01

    AGN jets carry helical magnetic fields, which can affect dark matter if the latter is axionic. This preliminary study shows that the nature of the axionic condensate may change and instead of dark matter may behave more like exotic matter, which violates the null energy condition. If the central supermassive black hole of an active galaxy is laced with exotic matter then it may become a wormhole. In general, the presence of exotic matter may affect galaxy formation and galactic dynamics, so this possibility should not be ignored when considering axionic dark matter.

  19. Suppressing the QCD axion abundance by hidden monopoles

    Energy Technology Data Exchange (ETDEWEB)

    Kawasaki, Masahiro [Tokyo Univ., Chiba (Japan). Inst. for Cosmic Ray Research; Tokyo Univ., Chiba (Japan). Kavli IPMU (WPI), UTIAS; Takahashi, Fuminobu [Tokyo Univ., Miyagi (Japan). Dept. of Physics; Tokyo Univ., Chiba (Japan). Kavli IPMU (WPI), UTIAS; Yamada, Masaki [Tokyo Univ., Chiba (Japan). Inst. for Cosmic Ray Research; Tokyo Univ., Chiba (Japan). Kavli IPMU (WPI), UTIAS; DESY Hamburg (Germany)

    2015-11-15

    We study the Witten effect of hidden monopoles on the QCD axion dynamics, and show that its abundance as well as isocurvature perturbations can be significantly suppressed if there is a sufficient amount of hidden monopoles. When the hidden monopoles make up a significant fraction of dark matter, the Witten effect suppresses the abundance of axion with the decay constant smaller than 10{sup 12} GeV. The cosmological domain wall problem of the QCD axion can also be avoided, relaxing the upper bound on the decay constant when the Peccei-Quinn symmetry is spontaneously broken after inflation.

  20. Axion cyclotron emissivity of magnetized white dwarfs and neutron stars

    OpenAIRE

    Kachelriess, M.; Wilke, C.; Wunner, G.

    1997-01-01

    The energy loss rate of a magnetized electron gas emitting axions a due to the process $e^- \\to e^- +a$ is derived for arbitrary magnetic field strength B. Requiring that for a strongly magnetized neutron star the axion luminosity is smaller than the neutrino luminosity we obtain the bound $g_{ae}\\lsim 10^{-10}$ for the axion electron coupling constant. This limit is considerably weaker than the bound derived earlier by Borisov and Grishina using the same method. Applying a similar argument t...

  1. Axion Emission from Red Giants and White Dwarfs

    CERN Document Server

    Altherr, Tanguy; Gaztelurrutia, T R

    1994-01-01

    Using thermal field theory methods, we recalculate axion emission from dense plasmas. We study in particular the Primakoff and the bremsstrahlung processes. The Primakoff rate is significantly suppressed at high densities, when the electrons become relativistic. However, the bound on the axion-photon coupling, $G<10^{-10}$ GeV, is unaffected, as it is constrained by the evolution of HB stars, which have low densities. In contradistinction, the same relativistic effects enhance the bremsstrahlung processes. From the red giants and white dwarfs evolution, we obtain a conservative bound on the axion-electron coupling, $g_{ae} < 2\\times 10^{-13}$.

  2. Accelerating dark-matter axion searches with quantum measurement technology

    CERN Document Server

    Zheng, Huaixiu; Brierley, R T; Girvin, S M; Lehnert, K W

    2016-01-01

    The axion particle, a consequence of an elegant hypothesis that resolves the strong-CP problem of quantum chromodynamics, is a plausible origin for cosmological dark matter. In searches for axionic dark matter that detect the conversion of axions to microwave photons, the quantum noise associated with microwave vacuum fluctuations will soon limit the rate at which parameter space is searched. Here we show that this noise can be partially overcome either by squeezing the quantum vacuum using recently developed Josephson parametric devices, or by using superconducting qubits to count microwave photons.

  3. An argument that the dark matter is axions

    OpenAIRE

    Sikivie, P.

    2012-01-01

    An argument is presented that the dark matter is axions, at least in part. It has three steps. First, axions behave differently from the other forms of cold dark matter because they form a rethermalizing Bose-Einstein condensate (BEC). Second, there is a tool to distinguish axion BEC from the other dark matter candidates on the basis of observation, namely the study of the inner caustics of galactic halos. Third, the observational evidence for caustic rings of dark matter is consistent in eve...

  4. High-energy gamma-ray emission from solar flares: Summary of Fermi large area telescope detections and analysis of two M-class flares

    Energy Technology Data Exchange (ETDEWEB)

    Ackermann, M. [Deutsches Elektronen Synchrotron DESY, D-15738 Zeuthen (Germany); Ajello, M. [Space Sciences Laboratory, 7 Gauss Way, University of California, Berkeley, CA 94720-7450 (United States); Albert, A. [Department of Physics, Center for Cosmology and Astro-Particle Physics, The Ohio State University, Columbus, OH 43210 (United States); Allafort, A.; Bechtol, K.; Bottacini, E.; Buehler, R. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Baldini, L. [Università di Pisa and Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa (Italy); Barbiellini, G. [Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, I-34127 Trieste (Italy); Bastieri, D.; Buson, S. [Istituto Nazionale di Fisica Nucleare, Sezione di Padova, I-35131 Padova (Italy); Bellazzini, R.; Bregeon, J. [Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa (Italy); Bissaldi, E. [Institut für Astro- und Teilchenphysik and Institut für Theoretische Physik, Leopold-Franzens-Universität Innsbruck, A-6020 Innsbruck (Austria); Bonamente, E. [Istituto Nazionale di Fisica Nucleare, Sezione di Perugia, I-06123 Perugia (Italy); Bouvier, A. [Santa Cruz Institute for Particle Physics, Department of Physics and Department of Astronomy and Astrophysics, University of California at Santa Cruz, Santa Cruz, CA 95064 (United States); Brandt, T. J. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Brigida, M. [Dipartimento di Fisica " M. Merlin" dell' Università e del Politecnico di Bari, I-70126 Bari (Italy); Bruel, P. [Laboratoire Leprince-Ringuet, École polytechnique, CNRS/IN2P3, F-91128 Palaiseau (France); Caliandro, G. A., E-mail: allafort@stanford.edu, E-mail: nicola.omodei@stanford.edu [Institut de Ciències de l' Espai (IEEE-CSIC), Campus UAB, E-08193 Barcelona (Spain); and others

    2014-05-20

    We present the detections of 18 solar flares detected in high-energy γ-rays (above 100 MeV) with the Fermi Large Area Telescope (LAT) during its first 4 yr of operation. This work suggests that particle acceleration up to very high energies in solar flares is more common than previously thought, occurring even in modest flares, and for longer durations. Interestingly, all these flares are associated with fairly fast coronal mass ejections (CMEs). We then describe the detailed temporal, spatial, and spectral characteristics of the first two long-lasting events: the 2011 March 7 flare, a moderate (M3.7) impulsive flare followed by slowly varying γ-ray emission over 13 hr, and the 2011 June 7 M2.5 flare, which was followed by γ-ray emission lasting for 2 hr. We compare the Fermi LAT data with X-ray and proton data measurements from GOES and RHESSI. We argue that the γ-rays are more likely produced through pion decay than electron bremsstrahlung, and we find that the energy spectrum of the proton distribution softens during the extended emission of the 2011 March 7 flare. This would disfavor a trapping scenario for particles accelerated during the impulsive phase of the flare and point to a continuous acceleration process at play for the duration of the flares. CME shocks are known for accelerating the solar energetic particles (SEPs) observed in situ on similar timescales, but it might be challenging to explain the production of γ-rays at the surface of the Sun while the CME is halfway to the Earth. A stochastic turbulence acceleration process occurring in the solar corona is another likely scenario. Detailed comparison of characteristics of SEPs and γ-ray-emitting particles for several flares will be helpful to distinguish between these two possibilities.

  5. High-energy gamma-ray emission from solar flares: Summary of Fermi large area telescope detections and analysis of two M-class flares

    International Nuclear Information System (INIS)

    We present the detections of 18 solar flares detected in high-energy γ-rays (above 100 MeV) with the Fermi Large Area Telescope (LAT) during its first 4 yr of operation. This work suggests that particle acceleration up to very high energies in solar flares is more common than previously thought, occurring even in modest flares, and for longer durations. Interestingly, all these flares are associated with fairly fast coronal mass ejections (CMEs). We then describe the detailed temporal, spatial, and spectral characteristics of the first two long-lasting events: the 2011 March 7 flare, a moderate (M3.7) impulsive flare followed by slowly varying γ-ray emission over 13 hr, and the 2011 June 7 M2.5 flare, which was followed by γ-ray emission lasting for 2 hr. We compare the Fermi LAT data with X-ray and proton data measurements from GOES and RHESSI. We argue that the γ-rays are more likely produced through pion decay than electron bremsstrahlung, and we find that the energy spectrum of the proton distribution softens during the extended emission of the 2011 March 7 flare. This would disfavor a trapping scenario for particles accelerated during the impulsive phase of the flare and point to a continuous acceleration process at play for the duration of the flares. CME shocks are known for accelerating the solar energetic particles (SEPs) observed in situ on similar timescales, but it might be challenging to explain the production of γ-rays at the surface of the Sun while the CME is halfway to the Earth. A stochastic turbulence acceleration process occurring in the solar corona is another likely scenario. Detailed comparison of characteristics of SEPs and γ-ray-emitting particles for several flares will be helpful to distinguish between these two possibilities.

  6. Detection of zero anisotropy at 5.2 AU during the November 1998 solar particle event: Ulysses Anisotropy Telescopes observations

    OpenAIRE

    Dalla, S.; Balogh, A.

    2000-01-01

    For the first time during the mission, the Anisotropy Telescopes instrument on board the Ulysses spacecraft measured constant zero anisotropy of protons in the 1.3-2.2 MeV energy range, for a period lasting more than three days. This measurement was made during the energetic particle event taking place at Ulysses between 25 November and 15 December 1998, an event characterised by constant high proton fluxes within a region delimited by two interplanetary forward shocks, at a distance of 5.2 A...

  7. Hubble Space Telescope Configuration

    Science.gov (United States)

    1985-01-01

    This image illustrates the overall Hubble Space Telescope (HST) configuration. The HST is the product of a partnership between NASA, European Space Agency Contractors, and the international community of astronomers. It is named after Edwin P. Hubble, an American Astronomer who discovered the expanding nature of the universe and was the first to realize the true nature of galaxies. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth orbit. By placing the telescope in space, astronomers are able to collect data that is free of the Earth's atmosphere. The HST detects objects 25 times fainter than the dimmest objects seen from Earth and provides astronomers with an observable universe 250 times larger than visible from ground-based telescopes, perhaps as far away as 14 billion light-years. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. The major elements of the HST are the Optical Telescope Assembly (OTA), the Support System Module (SSM), and the Scientific Instruments (SI). The HST is approximately the size of a railroad car, with two cylinders joined together and wrapped in a silvery reflective heat shield blanket. Wing-like solar arrays extend horizontally from each side of these cylinders, and dish-shaped anternas extend above and below the body of the telescope. The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Connecticut, developed the optical system and guidance sensors. The Lockheed Missile and Space Company of Sunnyvale, California produced the protective outer shroud and spacecraft systems, and assembled and tested the finished telescope.

  8. Fermi Large Area Telescope observations of high-energy gamma-ray emission from behind-the-limb solar flares

    CERN Document Server

    Pesce-Rollins, Melissa; Petrosian, Vahe'; Liu, Wei; da Costa, Fatima Rubio; Allafort, Alice

    2015-01-01

    Fermi-LAT >30 MeV observations have increased the number of detected solar flares by almost a factor of 10 with respect to previous space observations. These sample both the impulsive and long duration phases of GOES M and X class flares. Of particular interest is the recent detections of three solar flares whose position behind the limb was confirmed by the STEREO-B spacecraft. While gamma-ray emission up to tens of MeV resulting from proton interactions has been detected before from occulted solar flares, the significance of these particular events lies in the fact that these are the first detections of >100 MeV gamma-ray emission from footpoint-occulted flares. We will present the Fermi-LAT, RHESSI and STEREO observations of these flares and discuss the various emission scenarios for these sources and implications for the particle acceleration mechanisms.

  9. D6-branes and axion monodromy inflation

    CERN Document Server

    Escobar, Dagoberto; Marchesano, Fernando; Regalado, Diego

    2015-01-01

    We develop new scenarios of large field inflation in type IIA string compactifications in which the key ingredient is a D6-brane that creates a potential for a B-field axion. The potential has the multi-branched structure typical of F-term axion monodromy models and, near its supersymmetric minima, it is described by a 4d supergravity model of chaotic inflation with a stabiliser field. The same statement applies to the D6-brane Wilson line, which can also be considered as an inflaton candidate. We analyse both cases in the context of type IIA moduli stabilisation, finding an effective potential for the inflaton system and a simple mechanism to lower the inflaton mass with respect to closed string moduli stabilised by fluxes. Finally, we compute the B-field potential for trans-Planckian field values by means of the DBI action. The effect of Planck suppressed corrections is a flattened potential which, in terms of the compactification parameters, interpolates between linear and quadratic inflation. This renders...

  10. Axion dark matter from topological defects

    CERN Document Server

    Kawasaki, Masahiro; Sekiguchi, Toyokazu

    2014-01-01

    The cosmological scenario where the Peccei-Quinn symmetry is broken after inflation is investigated. In this scenario, topological defects such as strings and domain walls produce a large amount of axions, which contribute to the cold dark matter of the universe. The previous estimations of the cold dark matter abundance are updated and refined based on the field-theoretic simulations with improved grid sizes. The possible uncertainties originated in the numerical calculations are also discussed. It is found that axions can be responsible for the cold dark matter in the mass range $m_a=(0.9$-$1.4)\\times 10^{-4}\\mathrm{eV}$ for the models with the domain wall number $N_{\\rm DW}=1$, and $m_a\\approx\\mathcal{O}(10^{-4}$-$10^{-2})\\mathrm{eV}$ with a mild tuning of parameters for the models with $N_{\\rm DW}>1$. Such higher mass ranges can be probed in the future experimental studies.

  11. Non-gaussianity from axion monodromy inflation

    Energy Technology Data Exchange (ETDEWEB)

    Hannestad, Steen; Haugbolle, Troels; Jarnhus, Philip R. [Department of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C (Denmark); Sloth, Martin S., E-mail: sth@phys.au.dk, E-mail: haugboel@nbi.ku.dk, E-mail: pjarn@phys.au.dk, E-mail: martin.sloth@cern.ch [CERN, Physics Department, Theory Unit, CH-1211 Geneva 23 (Switzerland)

    2010-06-01

    We study the primordial non-Gaussianity predicted from simple models of inflation with a linear potential and superimposed oscillations. This generic form of the potential is predicted by the axion monodromy inflation model, that has recently been proposed as a possible realisation of chaotic inflation in string theory, where the monodromy from wrapped branes extends the range of the closed string axions to beyond the Planck scale. The superimposed oscillations in the potential can lead to new signatures in the CMB spectrum and bispectrum. In particular the bispectrum will have a new distinct shape. We calculate the power spectrum and bispectrum of curvature perturbations in the model, as well as make analytic estimates in various limiting cases. From the numerical analysis we find that for a wide range of allowed parameters the model produces a feature in the bispectrum with f{sub NL} ∼ 5−50 or larger while the power spectrum is almost featureless. This model is therefore an example of a string inspired inflationary model which is testable mainly through its non-Gaussian features. Finally we provide a simple analytic fitting formula for the bispectrum which is accurate to approximately 5 % in all cases, and easily implementable in codes designed to provide non-Gaussian templates for CMB analyses.

  12. Non-gaussianity from axion monodromy inflation

    International Nuclear Information System (INIS)

    We study the primordial non-Gaussianity predicted from simple models of inflation with a linear potential and superimposed oscillations. This generic form of the potential is predicted by the axion monodromy inflation model, that has recently been proposed as a possible realisation of chaotic inflation in string theory, where the monodromy from wrapped branes extends the range of the closed string axions to beyond the Planck scale. The superimposed oscillations in the potential can lead to new signatures in the CMB spectrum and bispectrum. In particular the bispectrum will have a new distinct shape. We calculate the power spectrum and bispectrum of curvature perturbations in the model, as well as make analytic estimates in various limiting cases. From the numerical analysis we find that for a wide range of allowed parameters the model produces a feature in the bispectrum with fNL ∼ 5−50 or larger while the power spectrum is almost featureless. This model is therefore an example of a string inspired inflationary model which is testable mainly through its non-Gaussian features. Finally we provide a simple analytic fitting formula for the bispectrum which is accurate to approximately 5 % in all cases, and easily implementable in codes designed to provide non-Gaussian templates for CMB analyses

  13. Vacuum statistics and stability in axionic landscapes

    Science.gov (United States)

    Masoumi, Ali; Vilenkin, Alexander

    2016-03-01

    We investigate vacuum statistics and stability in random axionic landscapes. For this purpose we developed an algorithm for a quick evaluation of the tunneling action, which in most cases is accurate within 10%. We find that stability of a vacuum is strongly correlated with its energy density, with lifetime rapidly growing as the energy density is decreased. On the other hand, the probability P(B) for a vacuum to have a tunneling action B greater than a given value declines as a slow power law in B. This is in sharp contrast with the studies of random quartic potentials, which found a fast exponential decline of P(B). Our results suggest that the total number of relatively stable vacua (say, with B>100) grows exponentially with the number of fields N and can get extremely large for Ngtrsim 100. The problem with this kind of model is that the stable vacua are concentrated near the absolute minimum of the potential, so the observed value of the cosmological constant cannot be explained without fine-tuning. To address this difficulty, we consider a modification of the model, where the axions acquire a quadratic mass term, due to their mixing with 4-form fields. This results in a larger landscape with a much broader distribution of vacuum energies. The number of relatively stable vacua in such models can still be extremely large.

  14. Fermi Large Area Telescope observations of high-energy gamma-ray emission from behind-the-limb solar flares

    OpenAIRE

    Pesce-Rollins, Melissa; Omodei, Nicola; Petrosian, Vahe; Wei LIU; da Costa, Fatima Rubio; Allafort, Alice; Collaboration, for the Fermi-LAT

    2015-01-01

    Fermi-LAT >30 MeV observations have increased the number of detected solar flares by almost a factor of 10 with respect to previous space observations. These sample both the impulsive and long duration phases of GOES M and X class flares. Of particular interest is the recent detections of three solar flares whose position behind the limb was confirmed by the STEREO-B spacecraft. While gamma-ray emission up to tens of MeV resulting from proton interactions has been detected before from occulte...

  15. NEAT, An Astrometric Telescope To Probe Planetary Systems Down To The Earth Mass Around Nearby Solar-Type Stars

    CERN Document Server

    Malbet, F; Goullioud, R; Shao, M; Lagage, P -O; Cara, C; Durand, G; Feautrier, P; Jakobsson, B; Hinglais, E; Mercier, M

    2011-01-01

    The NEAT (Nearby Earth Astrometric Telescope) mission is a proposition submitted to ESA for its 2010 call for M-size mission. The main scientific goal is to detect and characterize planetary systems in an exhaustive way down to 1 Earth mass in the habitable zone and further away, around nearby stars for F, G, and K spectral types. This survey would provide the actual planetary masses, the full characterization of the orbits including their inclination, for all the components of the planetary system down to that mass limit. Extremely- high-precision astrometry, in space, can detect the dynamical effect due to even low mass orbiting planets on their central star, reaching those scientific goals. NEAT will continue the work performed by Hipparcos (1mas precision) and Gaia (7{\\mu}as aimed) by reaching a precision that is improved by two orders of magnitude (0.05{\\mu}as, 1{\\sigma} accuracy). The two modules of the payload, the telescope and the focal plane, must be placed 40m away leading to a formation flying opt...

  16. pn-CCDs in a Low-Background Environment: Detector Background of the CAST X-ray Telescope

    CERN Document Server

    Kuster, M; Cebrián, S; Franz, J; Friedrich, P; Hartmann, R; Kang, D; Kotthaus, R; Lutz, Gerhard; Rodriquez, A; Strüder, L

    2005-01-01

    The CAST experiment at CERN (European Organization of Nuclear Research) searches for axions from the sun. The axion is a pseudoscalar particle that was motivated by theory thirty years ago, with the intention to solve the strong CP problem. Together with the neutralino, the axion is one of the most promising dark matter candidates. The CAST experiment has been taking data during the last two years, setting an upper limit on the coupling of axions to photons more restrictive than from any other solar axion search in the mass range below 0.1 eV. In 2005 CAST will enter a new experimental phase extending the sensitivity of the experiment to higher axion masses. The CAST experiment strongly profits from technology developed for high energy physics and for X-ray astronomy: A superconducting prototype LHC magnet is used to convert potential axions to detectable X-rays in the 1-10 keV range via the inverse Primakoff effect. The most sensitive detector system of CAST is a spin-off from space technology, a Wolter I ty...

  17. The extreme UV imager telescope on-board the Solar Orbiter mission: overview of phase C and D

    Science.gov (United States)

    Halain, J.-P.; Rochus, P.; Renotte, E.; Hermans, A.; Jacques, L.; Auchère, F.; Berghmans, D.; Harra, L.; Schühle, U.; Schmutz, W.; Zhukov, A.; Aznar Cuadrado, R.; Delmotte, F.; Dumesnil, C.; Gyo, M.; Kennedy, T.; Smith, P.; Tandy, J.; Mercier, R.; Verbeeck, C.

    2015-09-01

    The Solar Orbiter mission is composed of ten scientific instruments dedicated to the observation of the Sun's atmosphere and its heliosphere, taking advantage of an out-of ecliptic orbit and at perihelion reaching a proximity close to 0.28 A.U. On board Solar Orbiter, the Extreme Ultraviolet Imager (EUI) will provide full-Sun image sequences of the solar corona in the extreme ultraviolet (17.1 nm and 30.4 nm), and high-resolution image sequences of the solar disk in the extreme ultraviolet (17.1 nm) and in the vacuum ultraviolet (121.6 nm). The EUI concept uses heritage from previous similar extreme ultraviolet instrument. Additional constraints from the specific orbit (thermal and radiation environment, limited telemetry download) however required dedicated technologies to achieve the scientific objectives of the mission. The development phase C of the instrument and its sub-systems has been successfully completed, including thermomechanical and electrical design validations with the Structural Thermal Model (STM) and the Engineering Model (EM). The instrument STM and EM units have been integrated on the respective spacecraft models and will undergo the system level tests. In parallel, the Phase D has been started with the sub-system qualifications and the flight parts manufacturing. The next steps of the EUI development will be the instrument Qualification Model (QM) integration and qualification tests. The Flight Model (FM) instrument activities will then follow with the acceptance tests and calibration campaigns.

  18. Aspects of axion phenomenology in a slice of AdS5

    International Nuclear Information System (INIS)

    Motivated by multi-throat considerations, we study the phenomenological implications of a bulk axion in a slice of AdS5 with a large extra dimension: k ∼ 10-2 eV, kR∼>O(1). In particular, we compare axion physics with a warped geometry to axions in flat compactifications. As in flat compactification scenarios, we find that the mass of the axion can become independent from the underlying Peccei-Quinn scale. Surprisingly, we find that in warped extra dimensions the axion's invisibility, cosmological viability, and basic phenomenology remain essentially unaltered in comparison to axions in flat compactifications

  19. Search of axions from a nuclear power reactor with a high-purity germanium detector

    International Nuclear Information System (INIS)

    This article reports the first study of possible emissions of axions from power reactors using Primakoff and Compton conversions as the detection mechanisms. The expected experimental signatures are mono-energetic lines produced by their Primakoff or Compton conversions at a high-purity germanium (HPGe) detector. No evidence of axion emissions were observed and constraints on axion couplings versus axion mass within the framework of invisible axion models were placed. This experimental approach provides a unique probe for axion mass at the keV-MeV range not accessible to the other techniques

  20. Observational Constraints on Axions as Quintessence in String Theory

    CERN Document Server

    Gupta, Gaveshna; Sen, Anjan A

    2011-01-01

    We study the observational constraints for the axion models in string theory which can successfully act as quintessence. The evolution of the universe in this model is sensitive to the initial value of the axion field. This initial value of the axion field controls deviation of the cosmic evolution from the \\Lambda CDM behaviour. We use the recent Union2 Supernova Type Ia dataset as well as the data from BAO measurements, the WMAP measurement of the shift parameter and the $H(z)$ measurements. Using these data, the reconstructed equation of state of the axion field has extremely small deviation from the cosmological constant \\omega = -1 even at 2\\sigma confidence level. One interesting outcome of this analysis is that one can put bound on the SUSY breaking scale using cosmological measurements assuming the values of different string related parameters and vice versa.

  1. Constraints on axion inflation from the weak gravity conjecture

    International Nuclear Information System (INIS)

    We derive constraints facing models of axion inflation based on decay constant alignment from a string-theoretic and quantum gravitational perspective. In particular, we investigate the prospects for alignment and ‘anti-alignment’ of C4 axion decay constants in type IIB string theory, deriving a strict no-go result in the latter case. We discuss the relationship of axion decay constants to the weak gravity conjecture and demonstrate agreement between our string-theoretic constraints and those coming from the ‘generalized’ weak gravity conjecture. Finally, we consider a particular model of decay constant alignment in which the potential of C4 axions in type IIB compactifications on a Calabi-Yau three-fold is dominated by contributions from D7-branes, pointing out that this model evades some of the challenges derived earlier in our paper but is highly constrained by other geometric considerations

  2. A scientist finally proves existence of elusive axion

    CERN Multimedia

    2006-01-01

    "Using a visual target/detector, a University of Buffalo researcher has revealed the existence of the axion, a tiny particle with no charge, a very low mass and a lifetime much shorter than a nanosecond." (1,5 page)

  3. The electroweak axion, dark energy, inflation and baryonic matter

    International Nuclear Information System (INIS)

    In a previous paper [1], the standard model was generalized to include an electroweak axion which carries baryon plus lepton number, B + L. It was shown that such a model naturally gives the observed value of the dark energy, if the scale of explicit baryon number violation A was chosen to be of the order of the Planck mass. In this paper, we consider the effect of the modulus of the axion field. Such a field must condense in order to generate the standard Goldstone boson associated with the phase of the axion field. This condensation breaks baryon number. We argue that this modulus might be associated with inflation. If an additional B − L violating scalar is introduced with a mass similar to that of the modulus of the axion field, we argue that decays of particles associated with this field might generate an acceptable baryon asymmetry

  4. Constraints on axion inflation from the weak gravity conjecture

    Energy Technology Data Exchange (ETDEWEB)

    Rudelius, Tom [Jefferson Physical Laboratory, Harvard University,Cambridge, MA 02138 (United States)

    2015-09-08

    We derive constraints facing models of axion inflation based on decay constant alignment from a string-theoretic and quantum gravitational perspective. In particular, we investigate the prospects for alignment and ‘anti-alignment’ of C{sub 4} axion decay constants in type IIB string theory, deriving a strict no-go result in the latter case. We discuss the relationship of axion decay constants to the weak gravity conjecture and demonstrate agreement between our string-theoretic constraints and those coming from the ‘generalized’ weak gravity conjecture. Finally, we consider a particular model of decay constant alignment in which the potential of C{sub 4} axions in type IIB compactifications on a Calabi-Yau three-fold is dominated by contributions from D7-branes, pointing out that this model evades some of the challenges derived earlier in our paper but is highly constrained by other geometric considerations.

  5. Non-thermal Axion Dark Radiation and Constraints

    CERN Document Server

    Mazumdar, Anupam; Saikawa, Ken'ichi

    2016-01-01

    The Peccei-Quinn mechanism presents a neat solution to the strong CP problem. As a by-product, it provides an ideal dark matter candidate, "the axion", albeit with a tiny mass. Axions therefore can act as dark radiation if excited with large momenta after the end of inflation. Nevertheless, the recent measurement of relativistic degrees of freedom from cosmic microwave background radiation strictly constrains the abundance of such extra relativistic species. We show that ultra-relativistic axions can be abundantly produced if the Peccei-Quinn field was initially displaced from the minimum of the potential. This in lieu places an interesting constraint on the axion dark matter window with large decay constant which is expected to be probed by future experiments. Moreover, an upper bound on the reheating temperature can be placed, which further constrains the thermal history of our Universe.

  6. Radio-loud magnetars as detectors for axions and axion-like particles

    International Nuclear Information System (INIS)

    We show that, by studying the arrival times of radio pulses from highly-magnetized transient beamed sources, it may be possible to detect light pseudo-scalar particles, such as axions and axion-like particles, whose existence could have considerable implications for the strong-CP problem of QCD as well as the dark matter problem in cosmology. Specifically, such light bosons may be detected with a much greater sensitivity, over a broad particle mass range, than is currently achievable by terrestrial experiments, and using indirect astrophysical considerations. The observable effect was discussed in Chelouche & Guendelman (2009), and is akin to the Stern-Gerlach experiment: the splitting of a photon beam naturally arises when finite coupling exists between the electro-magnetic field and the axion field. The splitting angle of the light beams linearly depends on the photon wavelength, the size of the magnetized region, and the magnetic field gradient in the transverse direction to the propagation direction of the photons. If radio emission in radio-loud magnetars is beamed and originates in regions with strong magnetic field gradients, then splitting of individual pulses may be detectable. We quantify the effect for a simplified model for magnetars, and search for radio beam splitting in the 2GHz radio light curves of the radio loud magnetar XTEJ1810-197. (author)

  7. Axion Cosmology with a Stronger QCD in the Early Universe

    OpenAIRE

    Choi, Kiwoon; Kim, Hang Bae; Kim, Jihn E.

    1996-01-01

    We examine in the context of supersymmetric models whether the usual cosmological upper bound on the axion decay constant can be relaxed by assuming a period of stronger QCD in the early universe. By evaluating the axion potential in the early universe and also taking into account the dilaton potential energy, it is argued that a stronger QCD is not useful for raising up the bound.

  8. Axion cosmology with a stronger QCD in the early universe

    Energy Technology Data Exchange (ETDEWEB)

    Choi Kiwoon [Korea Adv. Inst. of Sci. and Technol., Taejon (Korea, Republic of). Phys. Dept.; Kim, H.B. [Universidad Autonoma de Madrid (Spain). Dept. de Fisica Teorica; Kim, J.E. [Seoul National Univ. (Korea, Republic of). Dept. of Physics

    1997-04-14

    We examine in the context of supersymmetric models whether the usual cosmological upper bound on the axion decay constant can be relaxed by assuming a period of stronger QCD in the early universe. By evaluating the axion potential in the early universe and also taking into account the dilaton potential energy, it is argued that a stronger QCD is not useful for raising the bound. (orig.).

  9. Emergent Majorana mass and axion couplings in superfluids

    International Nuclear Information System (INIS)

    Axions (in the general sense) may acquire qualitatively new couplings inside superfluids. Their conventional couplings to fermions, in empty space, involve purely imaginary masses; the new couplings involve emergent Majorana masses. A generalized concept of Majorana mass is proposed, which allows continuous interpolation between Majorana and Dirac fermions, and also extension to bosons. The possibility of weak links for axions, recently put forward, is analyzed and replaced with a non-local analogue. (fast track communication)

  10. Class of Einstein-Maxwell-Dilaton-Axion Space-Times

    CERN Document Server

    Matos, Tonatiuh; Sanchez-Sanchez, Ruben; Wiederhold, Petra

    2009-01-01

    We use the harmonic maps ansatz to find exact solutions of the Einstein-Maxwell-Dilaton-Axion (EMDA) equations. The solutions are harmonic maps invariant to the symplectic real group in four dimensions $Sp(4,\\Rreal)\\sim O(5)$. We find solutions of the EMDA field equations for the one and two dimensional subspaces of the symplectic group. Specially, for illustration of the method, we find space-times that generalise the Schwarzschild solution with dilaton, axion and electromagnetic fields.

  11. Primakoff effect: synchrotron and coulomb mechanisms of axion emission

    International Nuclear Information System (INIS)

    For the first time the axion radiative emission by alternating electromagnetic field Fa → γa is considered due to Primakoff effect. As a concrete supplement, the synchrotron and Coulomb mechanisms are discussed and in the last case the alternating field is formed at the infinite motion of a charge in a Coulomb center field. The estimates for contributions of these effects into axion luminosity of magnetic neutron stars and the Sun are determined

  12. Primakoff effect: Synchrotron and Coulomb mechanisms of axion emission

    International Nuclear Information System (INIS)

    The Primakoff effect-induced radiative emission of axions by an alternating electromagnetic field, Fa → γa, is considered for the first time. The synchrotron mechanism and the Coulomb mechanism--in the latter case, the alternating field is formed when a charge executes an infinite motion in the field of a Coulomb center--are considered as specific examples. The contributions of these effects to the axion emissivity of magnetic neutron stars and of the Sun are estimated

  13. Spectral calibration of filters and detectors of solar EUV telescope for 13.2 nm for the TESIS experiment

    International Nuclear Information System (INIS)

    The full-sun EUV telescope for 13.2 nm spectral band for the TESIS experiment is designed to produce images of hot coronal plasma (T ∼ 10 MK). Calibration process of optical elements is presented. Spectral transmission of multilayer Zr/Si filters, sensitivity and radiation tolerance of CCD detector have been measured. Peak transmission of EUV filters in working, spectral band reaches 40-50% (filters with 50 and 55 layers are used), spectral dependence of transmission is close to calculated one. Transmission of filters in white light is equal to (1-2)x10-6. Sensitivity of CCD ranges from 0.01 to 0.1 ADC units per photon, radiation tolerance is better than 109 rad

  14. Searching for axions and ALPs from string theory

    CERN Document Server

    Ringwald, Andreas

    2012-01-01

    We review searches for closed string axions and axion-like particles (ALPs) in IIB string flux compactifications. For natural values of the background fluxes and TeV scale gravitino mass, the moduli stabilisation mechanism of the LARGE Volume Scenario predicts the existence of a QCD axion candidate with intermediate scale decay constant, f_a ~ 10^9 ... 10^12 GeV, associated with the small cycles wrapped by the branes hosting the visible sector, plus a nearly massless and nearly decoupled ALP associated with the LARGE cycle. In setups where the visible sector branes are wrapping more than the minimum number of two intersecting cycles, there are more ALPs which have approximately the same decay constant and coupling to the photon as the QCD axion candidate, but which are exponentially lighter. There are exciting phenomenological opportunities to search for these axions and ALPs in the near future. For f_a ~ 10^11 ... 10^12 GeV, the QCD axion can be the dominant part of dark matter and be detected in haloscopes ...

  15. Searching for axions and ALPs from string theory

    Energy Technology Data Exchange (ETDEWEB)

    Ringwald, Andreas

    2012-09-15

    We review searches for closed string axions and axion-like particles (ALPs) in IIB string flux compactifications. For natural values of the background fluxes and TeV scale gravitino mass, the moduli stabilisation mechanism of the LARGE Volume Scenario predicts the existence of a QCD axion candidate with intermediate scale decay constant, f{sub a} {proportional_to}10{sup 9/12} GeV, associated with the small cycles wrapped by the branes hosting the visible sector, plus a nearly massless and nearly decoupled ALP associated with the LARGE cycle. In setups where the visible sector branes are wrapping more than the minimum number of two intersecting cycles, there are more ALPs which have approximately the same decay constant and coupling to the photon as the QCD axion candidate, but which are exponentially lighter. There are exciting phenomenological opportunities to search for these axions and ALPs in the near future. For f{sub a} {proportional_to}10{sup 11/12} GeV, the QCD axion can be the dominant part of dark matter and be detected in haloscopes exploiting microwave cavities. For f{sub a} {proportional_to}10{sup 9/10} GeV, the additional ALPs could explain astrophysical anomalies and be searched for in the upcoming generation of helioscopes and light-shining-through-a-wall experiments.

  16. Natural Inflation with Multiple Sub-Planckian Axions

    CERN Document Server

    Choi, Kiwoon; Yun, Seokhoon

    2014-01-01

    We extend the Kim-Nilles-Peloso (KNP) alignment mechanism for natural inflation to models with N>2 axions, which obtains a super-Planckian effective axion decay constant f_{eff} >> M_{Pl} through an alignment of the anomaly coefficients of multiple axions having sub-Planckian fundamental decay constants f_0 O(100) as suggested by the recent BICEP2 results. We note that the KNP mechanism can be realized with the anomaly coefficients of O(1) if the number of axions N is large as N ln N > 2 ln (f_{eff}/f_0), in which case the effective decay constant can be exponentially enhanced as f_{eff}/f_0 ~ sqrt(N!) n^{N-1} for n denoting the typical size of the integer-valued anomaly coefficients. Comparing to the other multiple axion scenario, the N-flation scenario which requires N ~ f_{eff}^2/f_0^2, the KNP mechanism has a virtue of not invoking to a too large number of axions, although it requires a specific alignment of the anomaly coefficients, which can be achieved with a probability of O(f_0/f_{eff}) under a rand...

  17. Conversion and Operation of CAST as a massive axion detector

    CERN Document Server

    Elias, Nuno; Bordalo, Paula

    2010-01-01

    The axion was postulated after an elegant solution proposed by R. Peccei and H. Quinn to solve the strong CP problem of Quantum Chromodynamics. The CAST experiment searches for axions created in the core of the Sun. It uses an LHC superconducting prototype magnet to trigger the axion conversion into detectable X-ray photons. During its First Phase, with the magnetic field region kept under vacuum, CAST searched with high sensitivity for axion masses up to 0.02 eV/c2, for higher values the conversion coherence is lost. This thesis reflects the work that allows CAST to extend its search up to axion masses of 1 eV/c2. To restore the lost coherence a buffer gas is introduced in the magnet cold bores, such that the photon arising from the Primakoff conversion acquires an effective mass. The axion mass can be effectively scanned by fine tuning the gas density. The conversion of the experiment required the study, design and construction of a complex gas handling system to deal with a rare helium isotope, 3He. It rep...

  18. Second-generation dark-matter axion search

    Energy Technology Data Exchange (ETDEWEB)

    Sikivie, P.; Sullivan, N.S.; Tanner, D.B. [Univ. of Florida, Gainesville, FL (United States)

    1996-12-01

    This research project is a collaboration with the axion search experiment at Lawrence Livermore National Laboratory. The axion is a particle that affects two important issues in particle physics and astrophysics: the origin of CP symmetry in the strong interactions, and the composition of the dark-matter of the universe. First predicted in 1978, present laboratory, astrophysical, and cosmological constraints suggest axions have a mass in the 1 {mu}eV-1 meV range. Axions are especially significant as dark matter if their mass is in the range 1-10 {mu}eV. These dark matter axions may be detected by their coupling to photons through the E - B interaction in a tunable high-Q microwave cavity permeated by a strong external magnetic field. The present experiment is the first cavity experiment with the sensitivity to possibly observe cosmic axions. It has recently begun taking data and will operate for the next several years. The University of Florida plans to contribute to the operation of this detector and to the design and prototyping of cavities for the experiment.

  19. 3D Lumped LC Resonators as Low Mass Axion Haloscopes

    CERN Document Server

    McAllister, Ben T; Tobar, Michael E

    2016-01-01

    The axion is a hypothetical particle considered to be the most economical solution to the strong CP problem. It can also be formulated as a compelling component of dark matter. The haloscope, a leading axion detection scheme, relies on the conversion of galactic halo axions into real photons inside a resonant cavity structure in the presence of a static magnetic field, where the generated photon frequency corresponds to the mass of the axion. For maximum sensitivity it is key that the central frequency of the cavity mode structure coincides with the frequency of the generated photon. As the mass of the axion is unknown, it is necessary to perform searches over a wide range of frequencies. Currently there are substantial regions of the promising pre-inflationary low mass axion range without any viable proposals for experimental searches. We show that 3D resonant LC circuits with separated magnetic and electric fields, commonly known as re-entrant cavities, can be sensitive dark matter haloscopes in this region...

  20. Anisotropic plasmas from axion and dilaton deformations

    CERN Document Server

    Donos, Aristomenis; Sosa-Rodriguez, Omar

    2016-01-01

    We construct black hole solutions of type IIB supergravity that are holographically dual to anisotropic plasmas arising from deformations of an infinite class of four-dimensional CFTs. The CFTs are dual to $AdS_5\\times X_5$, where $X_5$ is an Einstein manifold, and the deformations involve the type IIB axion and dilaton, with non-trivial periodic dependence on one of the spatial directions of the CFT. At low temperatures the solutions approach smooth domain wall solutions with the same $AdS_5\\times X_5$ solution appearing in the far IR. For sufficiently large deformations an intermediate scaling regime appears which is governed by a Lifshitz-like scaling solution. We calculate the DC thermal conductivity and some components of the shear viscosity tensor.