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MAXIMA-1: A Measurement of the Cosmic Microwave Background Anisotropy on Angular Scales of 10' to 5 Degrees

Description: We present a map and an angular power spectrum of the anisotropy of the cosmic microwave background (CMB) from the first flight of MAXIMA. MAXIMA is a balloon-borne experiment with an array of 16 bolometric photometers operated at 100 mK. MAXIMA observed a 124 deg region of the sky with 10' resolution at frequencies of 150, 240 and 410 GHz. The data were calibrated using in-flight measurements of the CMB dipole anisotropy. A map of the CMB anisotropy was produced from three 150 and one 240 GHz … more
Date: October 2, 2000
Creator: Ade, P.; Balbi, A.; Bock, J.; Borrill, J.; Boscaleri, A.; deBernardis, P. et al.
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Partner: UNT Libraries Government Documents Department
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Design and testing of a superfluid liquid helium cooling loop

Description: This paper describes the design and preliminary testing of a cryogenic cooling loop that uses a thermomechanical pump to circulate superfluid liquid helium. The cooling loop test apparatus is designed to prove forced liquid helium flow concepts that will be used on the Astromag superconducting magnet facility. 3 refs., 2 figs.
Date: July 1, 1989
Creator: Gavin, L. M.; Green, M. A.; Levin, S. M.; Smoot, G. F. & Witebsky, C.
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Partner: UNT Libraries Government Documents Department
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Measurements of retractable gas-cooled 6061 aluminum electrical leads operating in a vacuum

Description: To charge and discharge the ASTROMAG superconducting magnet in space requires retractable gas-cooled leads which must operate in a vacuum. This report describes the design and test of 500 ampere retractable gas-cooled leads made from 6061-T4 aluminum tubes. Aluminum is attractive for gas-cooled electrical leads in space because of its low mass density and the desire for short leads. Initial tests showed that retractable gas-cooled leads could operate in a vacuum from a source of normal helium. … more
Date: June 1, 1991
Creator: Green, M. A.; Aguiar, H.; Bensadoun, M. J.; Gibson, J. H.; Heine, D. L.; Levin, S. et al.
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Partner: UNT Libraries Government Documents Department
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The ASTROMAG superconducting magnet facility configured for a free flying satellite

Description: ASTROMAG is a particle astrophysics facility that was originally configured for the Space Station. The heart of the ASTROMAG facility is a large superconducting magnet which is cooled using superfluid helium. The task of resizing the facility so that it will fly in a satellite in a high angle of inclination orbit is driven by the launch weight capability of the launch rocket and the desire to be able to do nearly the same physics as the Space Station version of ASTROMAG. In order to reduce the … more
Date: June 1, 1991
Creator: Green, M. A. & Smoot, G. F.
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Partner: UNT Libraries Government Documents Department
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Review of cosmic background radiation spectrum measurements: limits on distortions, energy release, and cosmological processes

Description: This paper reviews the three major cosmic microwave background radiation (CMBR) spectrum measurement programs conducted and published since the last (XVII) IAU General Assembly. The results are consistent with a Planckian spectrum with temperature 2.72 +- 0.03 K spanning a wavelength range of 0.1 to 12 cm. Limits on possible distortions and implications are outlined. Ongoing and future measurements are discussed.
Date: January 1, 1986
Creator: Smoot, G. F.
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Partner: UNT Libraries Government Documents Department
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ASTROMAG: A superconducting particle astrophysics magnet facility for the space station

Description: This paper describes a superconducting magnet system which is the heart of a particle astrophysics facility to be mounted on a portion of the proposed NASA space station. This facility will complete the studies done by the electromagnetic observatories now under development and construction by NASA. The paper outlines the selection process of the type of magnet to be used to analyze the energy and momentum of charged particles from deep space. The ASTROMAG superconducting magnet must meet all t… more
Date: September 1, 1986
Creator: Green, M. A.; Smoot, G. F.; Golden, R. L.; Israel, M. H.; Kephart, R.; Niemann, R. et al.
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Partner: UNT Libraries Government Documents Department
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Spectrum of the cosmic background radiation: early and recent measurements from the White Mountain Research Station

Description: The White Mountain Research Station has provided a support facility at a high, dry, radio-quiet site for measurements that have established the blackbody character of the cosmic microwave background radiation. This finding has confirmed the interpretation of the radiation as a relic of the primeval fireball and helped to establish the hot Big Bang theory as the standard cosmological model.
Date: September 1, 1985
Creator: Smoot, G. F.
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Partner: UNT Libraries Government Documents Department
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Formaldehyde Absorption toward W51

Description: We have measured formaldehyde (H{sub 2}CO) absorption toward the HII region complex W51A (G49.5-0.4) in the 6 cm and 2 cm wavelength rotational transitions with angular resolution of approximately 4 inch. The continuum HII region shows a large, previously undetected shell structure 5.5 pc along the major axis. We observe no H{sub 2}CO emission in regions of low continuum intensity. The absorption, converted to optical depth, shows a higher degree of clumping than previous maps at lower resoluti… more
Date: April 1, 1988
Creator: Kogut, A.; Smoot, G. F.; Bennett, C. L. & Petuchowski, S. J.
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Partner: UNT Libraries Government Documents Department
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Large-Angular-Scale Anisotropy in the Cosmic BackgroundRadiation

Description: We report the results of an extended series of airborne measurements of large-angular-scale anisotropy in the 3 K cosmic background radiation. Observations were carried out with a dual-antenna microwave radiometer operating at 33 GHz (0.89 cm wavelength) flown on board a U-2 aircraft to 20 km altitude. In eleven flights, between December 1976 and May 1978, the radiometer measured differential intensity between pairs of directions distributed over most of the northern hemisphere with an rms sens… more
Date: May 1, 1980
Creator: Gorenstein, M. V. & Smoot, G. F.
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Partner: UNT Libraries Government Documents Department
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The Spectrumof the Cosmic Background Radiation: Early and RecentMeasurements from the White Mountain Research Station

Description: The White Mountain Research Station has provided a support facility at a high, dry, radio-quiet site for measurements that have established the blackbody character of the cosmic microwave background radiation. This finding has confirmed the interpretation of the radiation as a relic of the primeval fireball and helped to establish the hot Big Bang theory as the standard cosmological model.
Date: September 1, 1985
Creator: Smoot, G. F.
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Partner: UNT Libraries Government Documents Department
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A Large L-Band Rectangular Corrugated Horn

Description: This paper describes a lightweight, corrugated-horn antenna, constructed from sheet metal. Over a 1.3-1.7 GHz operating band, its half-power beam width is approximately 20{sup o} in the E-plane and varies from 17{sup o} to 13{sup o} in the H-plane. Quarter-wave choke slots at the aperture help to reduce the E-plane sidelobes below -55 dB at angles greater than 90{sup o}, while the H-plane sidelobes lie in that range both with and without choke slots. Return loss throughout the operating band is… more
Date: January 1, 1987
Creator: Witebsky, C.; Smoot, G. F.; Levin, S. & Bensadoun, M.
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Partner: UNT Libraries Government Documents Department
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Measurements of the Cosmic Background Radiation Temperature at 3.3and 9.1 MM

Description: The authors report the results of measurements of the cosmic background radiation temperature at wavelengths of 9.1 and 3.3 mm. The 9.1 mm result, T{sub CBR} = 2.87 {+-} 0.21 K, is in good agreement with previous results and those obtained at longer wavelengths during the same experiment. The 3.3 mm result, T{sub CBR} = 2.4 {+-} 1.0 K, is consistent with previous measurements, but has a large error due to uncertainty in the atmospheric correction.
Date: June 1, 1983
Creator: Witebsky, C.; De Amici, G.; Smoot, G. F. & Friedman, S. D.
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Partner: UNT Libraries Government Documents Department
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A Measurement of the Cosmic Background Radiation Temperature at3.0 cm

Description: We describe a measurement of the cosmic background radiation temperature at a wavelength of 3.0 cm. The experiment was made in conjunction with measurements at four other wavelengths in an effort to measure the long wavelength spectrum to high accuracy. The result at 3 cm, T{sub CBR} = 2.91 {+-} 0.19 K, is in good agreement with the values at neighboring wavelengths, and consistent with previous results.
Date: June 1, 1983
Creator: Friedman, S. D.; Smoot, G. F.; De Amici, G. & Witebsky, C.
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Partner: UNT Libraries Government Documents Department
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New Measurements of the Cosmic Background Radiation Spectrum

Description: We have continued our program to measure the long-wavelength spectrum of the cosmic background radiation. Our previous observations were at five wavelengths--0.33, 0.9, 3.0, 6.3, and 12.0 cm--and had a weighted average value of 2.73 {+-} 0.05 K and deviated from a Planckian spectrum by less than 6%. In August 1984, we repeated our observations at 3.0, 0.9, and 0.33 cm and made new observations with a radiometer tunable from 1.7 to 15 cm. Preliminary analysis indicate that the new data are consi… more
Date: December 1, 1984
Creator: Smoot, G. F.; De Amici, G.; Levin, S. & Witebsky, C.
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Partner: UNT Libraries Government Documents Department
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Low-Frequency Measurements of the Cosmic Background Radiation Spectrum

Description: The long-wavelength spectrum of the cosmic background radiation has been measured at five wavelengths (0.33, 0.9, 3.0, 6.3, and 12.0 cm). These measurements represent a continuation of the work reported by Smoot et al. (1983). The combine results have a weighted average of 2.73 {+-} 0.05 K and are consistent with past measurements. They limit the possible Compton distortion of the Cosmic Background Radiation spectrum to less than 8%.
Date: November 1, 1984
Creator: Smoot, G. F.; De Amici, G.; Friedman, S. D.; Witebsky, C.; Sironi, G.; Bonelli, G. et al.
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Partner: UNT Libraries Government Documents Department
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The Cryogenic System for the ASTROMAG Test Coil

Description: This paper describes an all helium, low heat leak cryogenic system for the testing of a superconducting magnet coil for the ASTROMAG particle astrophysics experiment. The superconducting coil, which is projected to have a stored magnetic energy of 4 to 7 MJ, will be cooled by pumped helium from a liquid helium storage tank using a fountain effect helium II pump. The pumping system can be used to cool the cryogenic system down as well as keep the coil cold during its superconducting operation. T… more
Date: July 1, 1988
Creator: Green, M. A.; Levine, S. M.; Smoot, G. F. & Witebsky, C.
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Partner: UNT Libraries Government Documents Department
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Total Absorption Shower Counter Test

Description: We propose to conduct a short test to check the basic concepts used in the Total Absorption Shower Counter (TASC) being developed for the Alvarez cosmic-ray experiment (BCR-5) on the HEAO-B satellite. The objective is to ascertain whether the probability for an incoming proton of energy E {ge} 100 GeV to interact in the TASC and simulate the response due to an incoming e{sup {+-}} is smaller than 10{sup -4}. We will thereby obtain a preliminary estimate of whether the TASC should be able to dis… more
Date: November 3, 1972
Creator: Orth, C. D.; Smoot, G. F.; Smith, L. H.; Buffington, A.; Muller, R. A.; Dauber, P. M. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Long-Wavelength Measurements of the Cosmic Microwave BackgroundRadiation Spectrum

Description: We have measured the temperature of the cosmic microwave background radiation at wavelengths of 0.33, 3.0, 8.2 and 21.3 cm. These measurements represent a continuation of the work reported by Smoot et al. (1985). The new results have a weighted average of 2.70 {+-} 0.05 K and are consistent with past measurements. They limit the possible distortion of the cosmic microwave background radiation spectrum to less than 6%. The results of all measurements to date are consistent with a Planckian spect… more
Date: February 1, 1987
Creator: Smoot, G. F.; Bensadoun, M.; Bersanelli, M.; De Amici, G.; Kogut, A.; Levine, S. et al.
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Partner: UNT Libraries Government Documents Department
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Measurement of the Intensity of the Cosmic Background Radiation at3.7 GHz

Description: We measured the temperature of the cosmic background radiation (CBR) at a frequency of 3.7 GHz (8.1 cm wavelength), using a total power, direct RF-gain receiver. The results give a brightness temperature, T{sub CBR}, of 2.58 {+-} 0.13 K (68% C.L.). Details of the instrument and of the experimental procedure are given. This measurement is part of a larger experiment to measure the spectrum of the Cosmic Background Radiation between 0.6 and 90 GHz (50 and 0.33 cm wavelength).
Date: April 1, 1987
Creator: De Amici, G.; Smoot, G. F.; Aymon, J.; Bersanelli, M.; Kogut, A.; Levine, S. M. et al.
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Partner: UNT Libraries Government Documents Department
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Review of Cosmic Background Radiation Spectrum Measurements:Limits on Distortions, Energy Release, and Cosmological Processes

Description: This paper reviews the three major cosmic microwave background radiation (CMBR) spectrum measurement programs conducted and published since the last (XVII) IAU General Assembly. The results are consistent with a Planckian spectrum with temperature 2.72 {+-} 0.03 K spanning a wavelength range of 0.1 to 12 cm. Limits on possible distortions and implications are outlined. Ongoing and future measurements are discussed.
Date: January 1, 1986
Creator: Smoot, G. F.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Low Frequency measurment of the Spectrum of the Cosmic BackgroundRadiation

Description: We have made measurements of the cosmic background radiation spectrum at 5 wavelengths (0.33, 0.9, 3, 6.3, and 12 cm) using radiometers with wavelength-scaled corrugated horn antennas having very low sidelobes. A single large-mouth (0.7 m diameter) liquid-helium-cooled absolute reference load was used for all five radiometers. The results of the observations are consistent with previous measurements and represent a significant improvement in accuracy.
Date: June 1, 1983
Creator: Smoot, G. F.; De Amici, G.; Friedman, S. D.; Witebsky, C.; Mandolesi, N.; Partridge, R. B. et al.
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Partner: UNT Libraries Government Documents Department
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