Linear Polarization Components Research Articles

A complete characterization of x-ray polarization state by combination of single and multiple Bragg reflections

We present a simple method for complete determination of the x-ray polarization state, using just one Bragg reflection from a single-crystal analyzer. For the linear polarization components P1 and P2, we show that the usual method of using a 90° Bragg reflection can be extended to using any Bragg reflection with 2θ≠90°. For circular component P3, we use the intensity modulation profile in an azimuthal rotation caused by the phase-sensitive interference around a multiple-beam Bragg reflection. The combination of the two measurements allows a straightforward complete determination of x-ray polarization, including an unpolarized component, in a broad applicable energy range.

Elliptical polarimetry of the interacting binary stars V367 Cygni

view Abstract Citations (2) References (45) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Elliptical Polarimetry of the Interacting Binary Star V367 Cygni Elias, Nicholas M., II Abstract Elliptical polarization measures of the interacting binary star V367 Cyg were obtained. A two-component model for the circumbinary environment has been constructed. The variable linear polarization component arises from an electron envelope between the stars. Surrounding the entire system there is an extensive ring of material consisting of neutral hydrogen and dust which produces the constant linear polarization component. The variable circular polarization is probably produced by the circumbinary dust as well. Problems with the removal of the interstellar polarization and the light dilution from a nearby star are discussed. An alternative model of the binary based on systemic magnetic fields is discussed but eventually discounted. Suggestions for further observations are presented. Publication: The Astrophysical Journal Pub Date: June 1993 DOI: 10.1086/172795 Bibcode: 1993ApJ...410..785E Keywords: Astronomical Polarimetry; Binary Stars; Computational Astrophysics; Cosmic Dust; Light Curve; Linear Polarization; Stellar Envelopes; Astrophysics; STARS: BINARIES: CLOSE; STARS: CIRCUMSTELLAR MATTER; POLARIZATION; STARS: INDIVIDUAL CONSTELLATION NAME: V367 CYGNI full text sources ADS | data products SIMBAD (5)

100-MICRON ARRAY POLARIMETRY FROM THE KUIPER AIRBORNE OBSERVATORY: INSTRUMENTATION, TECHNIQUES, AND FIRST RESULTS

ABSTRACT The University of Chicago far-infrared array polarimeter, 'STOKES', is the first multiple-beam polarimeter for far-infrared astronomy. Observations are made from the NASA Kuiper Airborne Observatory. Two orthogonal components of linear polarization are detected simultaneously by corresponding pairs of bolometers in two 32-detector arrays. Novel observing and data-analysis techniques are used to overcome the inherent difficulties of array polarimetry. Results from the first observing flights with the new instrument are reported for the molecular clouds W3 and W51. The measurements show that the magnetic-field structure in both clouds is nonuniform on the scale of 0.5-1.5 pc. This is consistent with molecular line and Zeeman observations that indicate the presence of turbulent velocities and significant small-scale structure. Preliminary results from the second flight series have yielded approximately 40 new measurements in the Sgr A complex. These results indicate that modifications made since the first flights have significantly improved the performance of STOKES.

Realization of a measurement of a "weak value"

We present the first realization of a measurement of a ``weak value,'' a concept recently introduced by Aharonov, Albert, and Vaidman (AAV). Our experiment uses a birefringent crystal to separate the two linear-polarization components of a laser beam by a distance small compared to the laser-beam waist. This ``weak measurement'' is followed by a strong measurement which translates the centroid of the beam by a distance far larger than the birefringence-induced separation. In addition, we present data corresponding to orthogonal initial and final states, for which the weak value is not defined. This interference effect may have application in the amplification and detection of weak effects.

Polarization of Lyman- alpha radiation from hydrogen 2p excited by tilted-foil interaction.

We have observed the polarization of Lyman-..cap alpha.. radiation after the interaction of 70-keV protons with a thin tilted carbon foil. The circular polarization shows a sinusoidal dependence on the angle of tilt, whereas the components of linear polarization in the emitted radiation are found to be generally small. It is demonstrated that the polarization observed after the transmission through the foil at large angles of tilt extrapolates to the data obtained after the reflection of ions from the foil surface at grazing incidence.

Electron-Photon Coincidence Studies in Collisions of Polarized Electrons with Mercury Atoms

Electron-photon coincidences with initially polarized electrons have been measured for the first time. Results for linear and circular polarization components of the 254-nm line (Hg $6^{3}P_{1}\ensuremath{-}6^{1}S_{0}$ transition) are presented as a function of electron energy for electrons which are scattered inelastically ($6^{3}P_{1}$ excitation) in the forward direction. The analysis of these polarization components allows one to determine the role of spin-dependent interactions during collision as well as to determine the relative phase of the two scattering amplitudes involved.

Anticorrelations in the intensity fluctuations of orthogonally polarized components of the output of cw amplified spontaneous emission

The intensity fluctuations of orthogonal, linearly-polarized components of the cw amplified spontaneous emission output from one end of a 3.51 μm helix-xenon gas laser amplifier are found to be strongly anticorrelated when the amplifier is saturated. The anticorrelation appears to vanish at short discharge lengths as expected for a linear amplifier. Atomic memory effects are demonstrated by the crosscorrelation function which is up to three wider than the separated autocorrelation functions.

Synchrotron Radiation from Ends of Straight-Linear Interval

The phenomenon of synchrotron radiation interference (SRI) in the region of overlap of the electron radiation from the farther and closer ends of the straight--linear synchrotron interval was experimentally investigated. The experimental results on the dependences of the intensity of the SRI linear polarization components on the electron erergy in the optical region of the spectrum are presented. The angular distribution of the SRI polarization components was examined at fixed values of the electron energy. The value of the scattered magnetic field and the radius of the curved electron trajectory in the radiation points were determined by the position of the maximum in the experimentally investigated universal spectrum of synchrotron radiation.

Separation of the intrinsic and interstellar linear polarization components of southern hemisphere early-type emission-line stars

Separation of the intrinsic and interstellar linear polarization components of southern hemisphere early-type emission-line stars

Polarization and angular distribution of the radiation of electrons moving in a focusing magnetic field

The angular distribution of the linear-polarization components is found for the radiation of an electron moving in a nonuniform weak-focusing magnetic field. The distribution shape is studied as a function of the amplitudes of the axial and radial betatron oscillations. It is shown that the minimum intensity of the π component of the radiation does not vanish, in contrast with the case of a uniform field.

Further Polarization Studies of Grw+70°8247 and Other White Dwarfs

view Abstract Citations (71) References (10) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Further Polarization Studies of Grw+70°8247 and Other White Dwarfs Angel, J. R. P. ; Landstreet, J. D. Abstract Further observations of polarization in the white dwarf Grw+7008247 have been made. The circular polarization in a broad band from 4000 to 6000 A is found not to fluctuate by more than 3 percent on a time scale from 24 seconds to a few days. The circular polarization rises steeply from less than 1 percent at 3300 A to 3.5 percent at 4000 A, and then drops slowly to 2.5 percent at 7600 A. In ultraviolet and blue light the shows a component of linear polarization of between 2 and 3.5 percent at a position angle of about 20 Six other DC white dwarfs, one DA and one DBp, examined for circular polarization, gave null results generally to an accuracy of about 0.1 percent. Publication: The Astrophysical Journal Pub Date: October 1970 DOI: 10.1086/180623 Bibcode: 1970ApJ...162L..61A full text sources ADS | data products SIMBAD (9)

Measurements of the Linearly Polarized Components of Radio Sources at a Wavelength of 3.75 CM

view Abstract Citations (30) References (7) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Measurements of the Linearly Polarized Components of Radio Sources at a Wavelength of 3.75 CM Hobbs, R. W. ; Haddock, F. T. Abstract The linearly polarized component of 22 radio sources was studied at a wavelength of 3.75 cm (8 GHz) using the 85-foot reflector of the University of Michigan. The degree of polarization and position angle are given for seven galactic and fifteen extragalactic sources. Publication: The Astrophysical Journal Pub Date: March 1967 DOI: 10.1086/149082 Bibcode: 1967ApJ...147..908H full text sources ADS | data products NED (21)

A Survey of the Linearly Polarized Component of Galactic Radio Emission at 408 MC/S

This paper describes a survey of the sky for a linearly polarized component of the galactic radio emission. The observations were made at the frequency of 408 Mc/s with an aerial beamwidth of 8 degrees between half power points. The survey includes all the sky between δ = − 7°.5 to δ = 90°, observed in declination strips separated by 7°.5. The observations have been corrected for the spurious contributions from regions of sky outside the main beam. In the final analysis the position angles of the confirmed polarization vectors are corrected for the effects of the Faraday rotation in the ionosphere. It is believed that linearly polarized emission greater than 0.8 °K in magnitude could be detected with the polarimeter used in the observations. Thus a low upper limit is set for the regions of sky where no linearly polarized radiation has been observed. In two regions the polarization brightness temperature reaches 2–4 °K.

POLARIZATION OF RADAR ECHOES FROM AURORA

Auroral radar echoes at very high frequency received at antennas sensitive to linearly polarized components in directions symmetrical to the plane of polarization of the vertically polarized transmitted wave and the ground plane indicate that the received wave, in addition to an unpolarized component, contains a linear component of polarization tilted in the general direction of the earth's magnetic field lines.

Polarization of the 10-cm radiation from the Crab Nebula and other sources.

view Abstract Citations (5) References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Polarization of the 10-cm radiation from the Crab Nebula and other sources. Mayer, C. H. ; Sloanaker, R. M. Abstract A search was made for linearly-polarized components of the 10.2 cm radiation from the radio `sources Cassiopeia-A (IAU 23N5A), Taurus-A, the Crab Nebula (IAU 05N2A), Cygnus-A (IAU 19N4A), Virgo-A (IAU I2NIA), and M17 (IAU i8SiA) using the 84-foot reflector at the NRL Maryland Point Observatory. Only the radiation from the Crab Nebula showed characteristics which could be interpreted as due to a plane-polarized component of the radiation. The horn-type feed antenna at the focus of the reflector was rotated continuously about its axis by a motor drive causing the plane of polarization accepted by the antenna to rotate. After correction for instrumental effects, no plane-polarized component greater than I per cent was detected in the radiation of Cas-A, Cyg-A, or M17. The lower intensity of the radiation from Virgo-A did not allow as good precision of measurement, but an upper limit `of about 3 per cent can be placed on a linearly- polarized component. The Crab Nebula showed a distinctly different result from the other sources which can be interpreted as a linearly-polarized component of about 3 per cent of the total radiation with a position angle for the electric vector of about 135 degrees. The sources Cas-A, Cyg-A, and the Crab Nebula were measured at two other wave lengths as well, 11.3 cm and 11.5 cm. The results were similar at the three wave lengths indicating that there is little Faraday rotation along the path between the Crab Nebula and the earth. This conclusion is supported by the close agreement between these measurements of position angle at 11.5, 11.3, and 10.2 cm with those previously measured at 9.6 cm (Kuz'min and Udal'tsov 1959), at 3.15 cm (Mayer, McCullough, and Sloanaker 1957), and the average position angle measured optically (Oort and Walraven 1956). REFERENCES Kuz'min, A. D. and Udal'tsov, V. A. 1959, Astron. J. (USSR) 36 33. Mayer, C. H., McCullough, T. P. and Sloanal~r, R. M. 1957, Ap. J. 126, 468. Qort, J. H. and Wairaven, T. 1956, B. A. N. 12, 285. Radio Astronomy Branch U. S. Naval Research Laboratory Washington, D. C. Publication: The Astronomical Journal Pub Date: 1959 DOI: 10.1086/108001 Bibcode: 1959AJ.....64Q.339M full text sources ADS |