Comparison of photon-photon and photon-magnetic field pair production rates

1983 ◽  
Author(s):  
M. L. Burns ◽  
A. K. Harding
Keyword(s):  
Magnetic Field ◽  
Pair Production ◽  
Production Rates

Pair production in a rotating strong magnetic field

2002 ◽  
Vol 65 (12) ◽  
Author(s):  
Antonino Di Piazza ◽  
Giorgio Calucci
Keyword(s):  
Magnetic Field ◽  
Pair Production ◽  
Strong Magnetic Field

scholarly journals Scalar pair production in a magnetic field in de Sitter universe

2018 ◽  
Vol 78 (5) ◽  
Author(s):  
Mihaela-Andreea Băloi ◽  
Cosmin Crucean ◽  
Diana Popescu
Keyword(s):  
Magnetic Field ◽  
Pair Production ◽  
De Sitter ◽  
Sitter Universe ◽  
De Sitter Universe

scholarly journals A new look at the pair-production width in a strong magnetic field

2000 ◽  
Vol 495 (1-2) ◽  
pp. 105-113 ◽  
Author(s):  
W.F. Kao ◽  
Guey-Lin Lin ◽  
Jie-Jun Tseng
Keyword(s):  
Magnetic Field ◽  
Pair Production ◽  
Strong Magnetic Field ◽  
New Look

scholarly journals Pair production in a magnetic and radiation field in a pulsar magnetosphere

2015 ◽  
Vol 30 (25) ◽  
pp. 1550111 ◽  
Author(s):  
M. M. Diachenko ◽  
O. P. Novak ◽  
R. I. Kholodov
Keyword(s):  
Magnetic Field ◽  
Pair Production ◽  
Production Process ◽  
Cross Section ◽  
Photon Production ◽  
Photon Pair ◽  
Pulsar Magnetosphere ◽  
Plasma Generation ◽  
Resonant Case ◽  
Two Photon

In this paper one- and two-photon pair production in a subcritical magnetic field have been considered. Two-photon production has been studied in the resonant case, when the cross-section considerably increases compared to the non-resonant case. While one-photon pair production is considered to be the main mechanism of plasma generation in a pulsar magnetosphere, we suggest the existence of another one, which is resonant two-photon production process.

scholarly journals Two new submodels for the Modular Earth Submodel System (MESSy): New Aerosol Nucleation (NAN) and small ions (IONS) version 1.0

2018 ◽  
Author(s):  
Sebastian Ehrhart ◽  
Eimear M. Dunne ◽  
Hanna E. Manninen ◽  
Tuomo Nieminen ◽  
Jos Lelieveld ◽  
...  
Keyword(s):  
Pair Production ◽  
Production Rate ◽  
Aerosol Particle ◽  
Atmospheric Chemistry ◽  
Particle Formation ◽  
Ion Pair ◽  
New Particle Formation ◽  
Production Rates ◽  
Organic Species ◽  
Good Agreement

Abstract. Two new submodels for the Modular Earth Submodel System (MESSy) were developed. The New Aerosol Nucleation submodel (NAN) includes new parameterisations of aerosol particle formation rates published in recent years. These parameterisations include ion-induced nucleation and nucleation of pure organic species. NAN calculates the rate of new particle formation based on the aforementioned parameterisations for aerosol submodels in the ECHAM/MESSy Atmospheric chemistry - Climate (EMAC) model. The Ion pair production rate, needed to calculate the ion-induced or -mediated nucleation, is described using the new submodel IONS, which provides ion pair production rates for other submodels within the MESSy framework. Both new submodels were tested in EMAC simulations. These simulations showed good agreement with ground based observations.

scholarly journals A Magnetospheric Dichotomy for Pulsars with Extreme Inclinations

Universe ◽  
2021 ◽  
Vol 7 (12) ◽  
pp. 455
Author(s):  
Fan Zhang
Keyword(s):  
Magnetic Field ◽  
Pair Production ◽  
Small Range ◽  
Polar Cap ◽  
Stable Regime ◽  
Regime Changes ◽  
Period Derivative ◽  
High Fraction ◽  
Pulsar Wind ◽  
The Magnetic Field

In this work, we expand on a comment by Lyne et al. (2017), that intermittent pulsars tend to congregate near a stripe in the logarithmic period versus period-derivative diagram. Such a stripe represents a small range of polar cap electric potential. Taking into account also the fact (already apparent in their Figure 7, but not explicitly stated there) that high-fraction nulling pulsars also tend to reside within this and an additional stripe, we make the observation that the two stripes further match the “death lines” for double- and single-pole interpulses, associated with nearly orthogonal and aligned rotators, respectively. These extreme inclinations are known to suffer from pair production deficiencies, so we propose to explain intermittency and high-fraction nulling by reinvigorating some older quiescent (no pulsar wind or radio emission) “electrosphere” solutions. Specifically, as the polar potential drops below the two threshold bands (i.e., the two stripes), corresponding to the aligned and orthogonal rotators, their respective magnetospheres transition from being of the active pair-production-sustained-type into becoming the electrospheres, in which charges are only lifted from the star. The borderline cases sitting in the gap outside of the stable regime of either case manifest as high-fraction nullers. Hall evolution of the magnetic field inside orthogonally rotating neutron stars can furthermore drive secular regime changes, resulting in intermittent pulsars.

scholarly journals Warm protons at comet 67P/Churyumov-Gerasimenko – Implications for the infant bow shock

2020 ◽  
Author(s):  
Charlotte Goetz ◽  
Herbert Gunell ◽  
Fredrik Johansson ◽  
Kristie LLera ◽  
Hans Nilsson ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Electron Flux ◽  
Gas Production ◽  
Bow Shock ◽  
Future Research ◽  
Asymmetric Structure ◽  
Production Rates ◽  
Power Spectral ◽  
Phase Data ◽  
Comet 67P

Abstract. Multiple plasma boundaries have been observed at comet 67P/Churyumov-Gerasimenko. Among them was an infant bow shock, an asymmetric structure in the plasma environment that separates the less disturbed solar wind from a plasma with warmer, slower protons. Rosetta crossings of the infant bow shock have so far only been reported for two days. Here, we aim to investigate this phenomenon further by focusing on the proton behaviour and surveying all of the Rosetta comet phase data. We find over 300 events that match the proton signatures at the infant bow shock. We investigate the properties of the plasma and magnetic field at this boundary and the location where it can be found. We find that the protons are preferentially detected at intermediate gas production rates with a slight trend towards larger cometocentric distances for higher gas production rates. The events can mostly be found in the positive convective electric field hemisphere. Both results agree well with simulations of the infant bow shock. The properties of the plasma are harder to constrain, but there is a trend towards higher electron flux, lower magnetic field, higher magnetic field power spectral density, and higher density in the region that contains the warm protons. This is in partial agreement with the previous IBS definitions, however it also indicates that the plasma and this structure are highly non-stationary. For future research, Comet Interceptor, with its multi-point measurements, can help to disentangle the spatial and temporal effects and give more clarity on the influence of changing upstream conditions on the movement of boundaries in this unusual environment.

scholarly journals Electron-Positron Pair Photoproduction in a Strong Magnetic Field Through the Polarization Cascade

2020 ◽  
Vol 65 (3) ◽  
pp. 187
Author(s):  
M. Diachenko ◽  
O. Novak ◽  
R. Kholodov ◽  
A. Fomina
Keyword(s):  
Magnetic Field ◽  
Pair Production ◽  
Strong Magnetic Field ◽  
Single Photon ◽  
Threshold Value ◽  
Pair Creation ◽  
Landau Levels ◽  
Radiation Correction ◽  
Electron Positron ◽  
Electron Positron Pair

The process of the e−e+ pair photoproduction in a strong magnetic field through the polarization cascade (the creation of an e−e+ pair from a single photon and its subsequent annihilation to a single photon) has been considered. The kinematics of the process is analyzed, and the expression for the general amplitude is obtained. A radiation correction to the process of pair creation at the lowest Landau levels by a single photon is found in the case where the energy of this photon is close to the threshold value. A comparison with the process of e−e+ pair production by one photon is made.

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