The measurement of the energy of cosmic rays I—The electro-magnet and cloud chamber

1—The Construction and Performance of the Electro-Magnet The energy of the cosmic ray particles has been determined from the curvature of their tracks in a strong magnetic field by Kunze, and by Anderson. Kunze used a power of 500 kw in a copper solenoid weighing 1100 kg to give a magnetic field of 18,400 gauss over a chamber 16⋅4 cm in diameter. Anderson used an electro-magnet with heavy water-cooled copper coils and a relatively light iron yoke. A power of 440 kw gave a field of 15,000 gauss over a chamber 16⋅5 cm in diameter, the actual length of the tracks photographed being about 12 cm. In order to obtain a similar performance without the use of such a very large amount of electric power, an electro-magnet has been constructed of a more conventional design, that is with an iron yoke which is heavy compared with the weight of the copper coils. The iron yoke weighs about 8000 kg and the copper coils 3000 kg. Figs. 1 a and 1 b show the detail of the design, and fig. 2 shows a photograph of the magnet in use with the cloud chamber and subsidiary apparatus. The diameter of the pole face is 25 cm, and the gap can be varied from 5 to 20 cm by sliding one pole piece along the baseplate by means of a screw.

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The Origin and Dynamical Effects of the Magnetic Fields and Cosmic Rays in the Disk of the Galaxy

Symposium - International Astronomical Union ◽

10.1017/s0074180900004873 ◽

1970 ◽

Vol 39 ◽

pp. 168-183

Author(s):

E. N. Parker

Keyword(s):

Magnetic Field ◽

Cosmic Rays ◽

Magnetic Fields ◽

Dynamical Behavior ◽

Cosmic Ray ◽

Interested Reader ◽

Written Text ◽

The Galaxy ◽

Basic Ideas ◽

The Magnetic Field

The topic of this presentation is the origin and dynamical behavior of the magnetic field and cosmic-ray gas in the disk of the Galaxy. In the space available I can do no more than mention the ideas that have been developed, with but little explanation and discussion. To make up for this inadequacy I have tried to give a complete list of references in the written text, so that the interested reader can pursue the points in depth (in particular see the review articles Parker, 1968a, 1969a, 1970). My purpose here is twofold, to outline for you the calculations and ideas that have developed thus far, and to indicate the uncertainties that remain. The basic ideas are sound, I think, but, when we come to the details, there are so many theoretical alternatives that need yet to be explored and so much that is not yet made clear by observations.

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On the flux of high-energy cosmogenic neutrinos and the influence of the extragalactic magnetic field

Monthly Notices of the Royal Astronomical Society Letters ◽

10.1093/mnrasl/slz083 ◽

2019 ◽

Vol 488 (1) ◽

pp. L119-L122 ◽

Cited By ~ 1

Author(s):

David Wittkowski ◽

Karl-Heinz Kampert

Keyword(s):

Magnetic Field ◽

Cosmic Rays ◽

Large Scale ◽

Neutrino Flux ◽

Cosmic Ray ◽

High Energy ◽

Observation Time ◽

Cosmological Time ◽

Cosmic Background ◽

The Universe

ABSTRACT Cosmogenic neutrinos originate from interactions of cosmic rays propagating through the universe with cosmic background photons. Since both high-energy cosmic rays and cosmic background photons exist, the existence of high-energy cosmogenic neutrinos is certain. However, their flux has not been measured so far. Therefore, we calculated the flux of high-energy cosmogenic neutrinos arriving at the Earth on the basis of elaborate 4D simulations that take into account three spatial degrees of freedom and the cosmological time-evolution of the universe. Our predictions for this neutrino flux are consistent with the recent upper limits obtained from large-scale cosmic-ray experiments. We also show that the extragalactic magnetic field has a strong influence on the neutrino flux. The results of this work are important for the design of future neutrino observatories, since they allow to assess the detector volume and observation time that are necessary to detect high-energy cosmogenic neutrinos in the near future. An observation of such neutrinos would push multimessenger astronomy to hitherto unachieved energy scales.

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The Ulysses fast latitude scans: COSPIN/KET results

Annales Geophysicae ◽

10.5194/angeo-21-1275-2003 ◽

2003 ◽

Vol 21 (6) ◽

pp. 1275-1288 ◽

Cited By ~ 8

Author(s):

B. Heber ◽

G. Sarri ◽

G. Wibberenz ◽

C. Paizis ◽

P. Ferrando ◽

...

Keyword(s):

Magnetic Field ◽

Cosmic Rays ◽

Solar Magnetic Field ◽

Solar Maximum ◽

Cosmic Ray ◽

Galactic Cosmic Rays ◽

Solar Particle Events ◽

Interplanetary Magnetic Fields ◽

Solar Particle ◽

Interplanetary Physics

Abstract. Ulysses, launched in October 1990, began its second out-of-ecliptic orbit in December 1997, and its second fast latitude scan in September 2000. In contrast to the first fast latitude scan in 1994/1995, during the second fast latitude scan solar activity was close to maximum. The solar magnetic field reversed its polarity around July 2000. While the first latitude scan mainly gave a snapshot of the spatial distribution of galactic cosmic rays, the second one is dominated by temporal variations. Solar particle increases are observed at all heliographic latitudes, including events that produce >250 MeV protons and 50 MeV electrons. Using observations from the University of Chicago’s instrument on board IMP8 at Earth, we find that most solar particle events are observed at both high and low latitudes, indicating either acceleration of these particles over a broad latitude range or an efficient latitudinal transport. The latter is supported by "quiet time" variations in the MeV electron background, if interpreted as Jovian electrons. No latitudinal gradient was found for >106 MeV galactic cosmic ray protons, during the solar maximum fast latitude scan. The electron to proton ratio remains constant and has practically the same value as in the previous solar maximum. Both results indicate that drift is of minor importance. It was expected that, with the reversal of the solar magnetic field and in the declining phase of the solar cycle, this ratio should increase. This was, however, not observed, probably because the transition to the new magnetic cycle was not completely terminated within the heliosphere, as indicated by the Ulysses magnetic field and solar wind measurements. We argue that the new A<0-solar magnetic modulation epoch will establish itself once both polar coronal holes have developed.Key words. Interplanetary physics (cosmic rays; energetic particles; interplanetary magnetic fields)

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The Origin of the Most Energetic Galactic Cosmic Rays: Supernova Explosions into Massive Star Plasma Winds

Galaxies ◽

10.3390/galaxies7020048 ◽

2019 ◽

Vol 7 (2) ◽

pp. 48 ◽

Cited By ~ 1

Author(s):

Peter L. Biermann ◽

Philipp P. Kronberg ◽

Michael L. Allen ◽

Athina Meli ◽

Eun-Suk Seo

Keyword(s):

Magnetic Field ◽

Cosmic Rays ◽

Field Strength ◽

Magnetic Field Strength ◽

Space Station ◽

Cosmic Ray ◽

High Energy ◽

Galactic Cosmic Rays ◽

Starburst Galaxy ◽

Supergiant Star

We propose that the high energy Cosmic Ray particles up to the upturn commonly called the ankle, from around the spectral turn-down commonly called the knee, mostly come from Blue Supergiant star explosions. At the upturn, i.e., the ankle, Cosmic Rays probably switch to another source class, most likely extragalactic sources. To show this we recently compiled a set of Radio Supernova data where we compute the magnetic field, shock speed and shock radius. This list included both Blue and Red Supergiant star explosions; both data show the same magnetic field strength for these two classes of stars despite very different wind densities and velocities. Using particle acceleration theory at shocks, those numbers can be transformed into characteristic ankle and knee energies. Without adjusting any free parameters both of these observed energies are directly indicated by the supernova data. In the next step in the argument, we use the Supernova Remnant data of the starburst galaxy M82. We apply this analysis to Blue Supergiant star explosions: The shock will race to their outer edge with a magnetic field that is observed to follow over several orders of magnitude B ( r ) × r ∼ c o n s t . , with in fact the same magnetic field strength for such stellar explosions in our Galaxy, and other galaxies including M82. The speed is observed to be ∼0.1 c out to about 10 16 cm radius in the plasma wind. The Supernova shock can run through the entire magnetic plasma wind region at full speed all the way out to the wind-shell, which is of order parsec scale in M82. We compare and identify the Cosmic Ray spectrum in other galaxies, in the starburst galaxy M82 and in our Galaxy with each other; we suggest how Blue Supergiant star explosions can provide the Cosmic Ray particles across the knee and up to the ankle energy range. The data from the ISS-CREAM (Cosmic Ray Energetics and Mass Experiment at the International Space Station) mission will test this cosmic ray concept which is reasonably well grounded in two independent radio supernova data sets. The next step in developing our understanding will be to obtain future more accurate Cosmic Ray data near to the knee, and to use unstable isotopes of Cosmic Ray nuclei at high energy to probe the “piston” driving the explosion. We plan to incorporate these data with the physics of the budding black hole which is probably forming in each of these stars.

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Cosmic Ray Evidence for the Magnetic Configuration of the Heliosphere

Symposium - International Astronomical Union ◽

10.1017/s0074180900074957 ◽

1981 ◽

Vol 94 ◽

pp. 397-398

Author(s):

H. S. Ahluwalia

Keyword(s):

Magnetic Field ◽

Solar Wind ◽

Cosmic Rays ◽

Cosmic Ray ◽

Ground Level ◽

The Sun ◽

Ground Level Enhancement ◽

Solar Cosmic Rays ◽

Pile Up ◽

Scattered Component

Sekido and Murakami (1958) proposed the existence of the heliosphere to explain the scattered component of the solar cosmic rays. The heliosphere of their conception is a spherical shell around the sun. The shell contains a highly-irregular magnetic field and serves to scatter the cosmic rays emitted by the sun. It thereby gives rise to an isotropic component of solar cosmic rays, following the maximum in the ground level enhancement (GLE). Meyer et al. (1956) showed that a similar picture applies to the GLE of 23 February 1956. They conclude that the inner and outer radii of the shell should be 1.4 AU and 5 AU respectively. They suggest that a shell is formed by the “pile-up” of the solar wind under pressure exerted by the interstellar magnetic field, as suggested by Davis (1955).

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Cosmic-ray propagation around the Sun: investigating the influence of the solar magnetic field on the cosmic-ray Sun shadow

Astronomy and Astrophysics ◽

10.1051/0004-6361/201936306 ◽

2020 ◽

Vol 633 ◽

pp. A83

Author(s):

J. Becker Tjus ◽

P. Desiati ◽

N. Döpper ◽

H. Fichtner ◽

J. Kleimann ◽

...

Keyword(s):

Magnetic Field ◽

Solar Activity ◽

Solar Cycle ◽

Cosmic Rays ◽

Solar Magnetic Field ◽

Cosmic Ray ◽

High Energy ◽

High Solar Activity ◽

The Sun ◽

Theoretical Understanding

The cosmic-ray Sun shadow, which is caused by high-energy charged cosmic rays being blocked and deflected by the Sun and its magnetic field, has been observed by various experiments, such as Argo-YBJ, Tibet, HAWC, and IceCube. Most notably, the shadow’s size and depth was recently shown to correlate with the 11-year solar cycle. The interpretation of such measurements, which help to bridge the gap between solar physics and high-energy particle astrophysics, requires a solid theoretical understanding of cosmic-ray propagation in the coronal magnetic field. It is the aim of this paper to establish theoretical predictions for the cosmic-ray Sun shadow in order to identify observables that can be used to study this link in more detail. To determine the cosmic-ray Sun shadow, we numerically compute trajectories of charged cosmic rays in the energy range of 5−316 TeV for five different mass numbers. We present and analyze the resulting shadow images for protons and iron, as well as for typically measured cosmic-ray compositions. We confirm the observationally established correlation between the magnitude of the shadowing effect and both the mean sunspot number and the polarity of the magnetic field during the solar cycle. We also show that during low solar activity, the Sun’s shadow behaves similarly to that of a dipole, for which we find a non-monotonous dependence on energy. In particular, the shadow can become significantly more pronounced than the geometrical disk expected for a totally unmagnetized Sun. For times of high solar activity, we instead predict the shadow to depend monotonously on energy and to be generally weaker than the geometrical shadow for all tested energies. These effects should become visible in energy-resolved measurements of the Sun shadow, and may in the future become an independent measure for the level of disorder in the solar magnetic field.

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Latitudinal and radial variation of >2 GeV/n protons and alpha-particles at solar maximum: ULYSSES COSPIN/KET and neutron monitor network observations

Annales Geophysicae ◽

10.5194/angeo-21-1295-2003 ◽

2003 ◽

Vol 21 (6) ◽

pp. 1295-1302 ◽

Cited By ~ 9

Author(s):

A. V. Belov ◽

E. A. Eroshenko ◽

B. Heber ◽

V. G. Yanke ◽

A. Raviart ◽

...

Keyword(s):

Magnetic Field ◽

Cosmic Rays ◽

Neutron Monitor ◽

Solar Minimum ◽

Latitudinal Gradient ◽

Solar Maximum ◽

Cosmic Ray ◽

Galactic Cosmic Rays ◽

Alpha Particles ◽

Polar Regions

Abstract. Ulysses, launched in October 1990, began its second out-of-ecliptic orbit in September 1997. In 2000/2001 the spacecraft passed from the south to the north polar regions of the Sun in the inner heliosphere. In contrast to the first rapid pole to pole passage in 1994/1995 close to solar minimum, Ulysses experiences now solar maximum conditions. The Kiel Electron Telescope (KET) measures also protons and alpha-particles in the energy range from 5 MeV/n to >2 GeV/n. To derive radial and latitudinal gradients for >2 GeV/n protons and alpha-particles, data from the Chicago instrument on board IMP-8 and the neutron monitor network have been used to determine the corresponding time profiles at Earth. We obtain a spatial distribution at solar maximum which differs greatly from the solar minimum distribution. A steady-state approximation, which was characterized by a small radial and significant latitudinal gradient at solar minimum, was interchanged with a highly variable one with a large radial and a small – consistent with zero – latitudinal gradient. A significant deviation from a spherically symmetric cosmic ray distribution following the reversal of the solar magnetic field in 2000/2001 has not been observed yet. A small deviation has only been observed at northern polar regions, showing an excess of particles instead of the expected depression. This indicates that the reconfiguration of the heliospheric magnetic field, caused by the reappearance of the northern polar coronal hole, starts dominating the modulation of galactic cosmic rays already at solar maximum.Key words. Interplanetary physics (cosmic rays; energetic particles) – Space plasma physics (charged particle motion and acceleration)

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The energy loss of cosmic ray particles in metal plates

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1937.0111 ◽

1937 ◽

Vol 160 (901) ◽

pp. 304-323 ◽

Cited By ~ 20

Keyword(s):

Magnetic Field ◽

Energy Loss ◽

Cosmic Ray ◽

Metal Plate ◽

Usual Method ◽

Cloud Chamber ◽

Zero Magnetic Field ◽

Metal Plates ◽

Curvature Measurements ◽

The Difference

Measurements have been made of the energy loss of cosmic ray particles in metal plates, making use of a counter controlled cloud chamber in a magnetic field (Blackett 1936). A metal plate was placed across the centre of the chamber and the energy loss of a ray was deduced from the difference of the curvature of a track above and below the plate. Energy loss measurements by this method have been carried out by Anderson and Neddermeyer (1936) up to an energy of about 4 x 10 8 e-volts and recently by Crussard and Leprince-Ringuet (1937) up to an energy of 1·2 x 10 9 e-volts. The curvature measurements were made mainly by means of the optical null method recently described (Blackett 1937 a ) and this proved invaluable. It would have been hard to obtain so high an accuracy by the usual method of measuring coordinates. The curvature corrections to be applied to the measured curvatures were obtained by measurements on tracks in zero magnetic field (Blackett and Brode 1936). Two separate distortion curves were required, one for the top and one for the bottom of the chamber.

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