From Wikipedia, the free encyclopedia
Optical phenomenon
The
Askaryan radiation
[1]
[2]
[3]
[4]
also known as
Askaryan effect
is the phenomenon whereby a particle traveling faster than the
phase velocity
of
light
in a dense
dielectric
(such as salt, ice or the
lunar
regolith
) produces a shower of secondary charged particles which contains a charge
anisotropy
and emits a cone of
coherent
radiation in the
radio
or
microwave
part of the
electromagnetic spectrum
. The signal is a result of the
Cherenkov radiation
from individual particles in the shower. Wavelengths greater than the extent of the shower interfere constructively and thus create a radio or microwave signal which is strongest at the Cherenkov angle. The effect is named after
Gurgen Askaryan
, a Soviet-Armenian physicist who postulated it in 1962.
The radiation was first observed experimentally in 2000, 38 years after its theoretical prediction. So far the effect has been observed in
silica
sand
,
[5]
rock salt,
[6]
ice,
[7]
and Earth's atmosphere.
[8]
The effect is of primary interest in using bulk matter to detect ultra-high energy
neutrinos
. The
Antarctic Impulse Transient Antenna
(ANITA) experiment uses antennas attached to a balloon flying over
Antarctica
to detect the Askaryan radiation produced as cosmic neutrinos travel through the ice.
[9]
[10]
Several experiments have also used the
Moon
as a
neutrino detector
based on detection of the Askaryan radiation.
[11]
[12]
[13]
[14]
See also
[
edit
]
References
[
edit
]
- ^
Askar'yan, G. A. (1961).
"Excess negative charge of an electron-photon shower and its coherent radio emission"
.
Zh. Eksp. Teor. Fiz
.
41
(1961): 616--618.
- ^
Askar'yan, G. A. (September 1965).
"Coherent Radio Emission from Cosmic Showers in Air and in Dense Media"
(PDF)
.
Soviet Physics JETP
.
21
: 658.
- ^
Hanson, Jordan C; Connolly, Amy L (2016). "Complex Analysis of Askaryan Radiation: A Fully Analytic Treatment including the LPM effect and Cascade Form Factor".
Astroparticle Physics
.
91
: 75?89.
arXiv
:
1605.04975
.
Bibcode
:
2017APh....91...75H
.
doi
:
10.1016/j.astropartphys.2017.03.008
.
S2CID
118850005
.
- ^
Alvarez-Muniz, Jaime; Romero-Wolf, Andres; Zas, Enrique (2011-11-11).
"Practical and accurate calculations of Askaryan radiation"
.
Physical Review D
.
84
(10): 103003.
arXiv
:
1106.6283
.
Bibcode
:
2011PhRvD..84j3003A
.
doi
:
10.1103/PhysRevD.84.103003
.
ISSN
1550-7998
.
S2CID
119212570
.
- ^
Saltzberg, David; Gorham, P; Walz, D; Field, C; Iverson, R; Odian, A; Resch, G; Schoessow, P; Williams, D (2001). "Observation of the Askaryan Effect: Coherent Microwave Cherenkov Emission from Charge Asymmetry in High Energy Particle Cascades".
Physical Review Letters
.
86
(13): 2802?5.
arXiv
:
hep-ex/0011001
.
Bibcode
:
2001PhRvL..86.2802S
.
doi
:
10.1103/PhysRevLett.86.2802
.
PMID
11290043
.
S2CID
5600492
.
- ^
Gorham, P. W.; Saltzberg, D.; Field, R. C.; Guillian, E.; Milin?i?, R.; Mio?inovi?, P.; Walz, D.; Williams, D. (2005-07-21).
"Accelerator measurements of the Askaryan effect in rock salt: A roadmap toward teraton underground neutrino detectors"
.
Physical Review D
.
72
(2): 023002.
arXiv
:
astro-ph/0412128
.
Bibcode
:
2005PhRvD..72b3002G
.
doi
:
10.1103/PhysRevD.72.023002
.
ISSN
1550-7998
.
OSTI
1442457
.
S2CID
53870487
.
- ^
Gorham, P. W.; Barwick, S. W.; Beatty, J. J.; Besson, D. Z.; Binns, W. R.; Chen, C.; Chen, P.; Clem, J. M.; Connolly, A.; Dowkontt, P. F.; DuVernois, M. A. (2007-10-25).
"Observations of the Askaryan Effect in Ice"
.
Physical Review Letters
.
99
(17): 171101.
arXiv
:
hep-ex/0611008
.
Bibcode
:
2007PhRvL..99q1101G
.
doi
:
10.1103/PhysRevLett.99.171101
.
ISSN
0031-9007
.
PMID
17995315
.
S2CID
16332031
.
- ^
Buitink, Stijn; Corstanje, A.; Falcke, H; Horandel, J. R; Huege, T; Nelles, A; Rachen, J. P; Rossetto, L; Schellart, P; Scholten, O; Ter Veen, S; Thoudam, S; Trinh, T. N. G; Anderson, J; Asgekar, A; Avruch, I. M; Bell, M. E; Bentum, M. J; Bernardi, G; Best, P; Bonafede, A; Breitling, F; Broderick, J. W; Brouw, W. N; Bruggen, M; Butcher, H. R; Carbone, D; Ciardi, B; Conway, J. E; et al. (2016). "A large light-mass component of cosmic rays at 10
17
?10
17.5
electronvolts from radio observations".
Nature
.
531
(7592): 70?3.
arXiv
:
1603.01594
.
Bibcode
:
2016Natur.531...70B
.
doi
:
10.1038/nature16976
.
PMID
26935696
.
S2CID
205247687
.
- ^
"ANITA Project Overview"
. Archived from
the original
on 2015-09-24
. Retrieved
2006-06-17
.
- ^
"ARIANNA collaboration"
. Archived from
the original
on 2016-05-17
. Retrieved
2014-11-28
.
- ^
GLUE project
- ^
"NuMoon project"
. Archived from
the original
on 2009-09-17
. Retrieved
2010-02-05
.
- ^
LUNASKA project
- ^
RESUN project
External links
[
edit
]