Излучение
<<  Общие сведения о дозе излучения Светодиоды как источники излучения в ВОЛС  >>
Микроволновое и суб-тгц излучение вспышечной петли
Микроволновое и суб-тгц излучение вспышечной петли
Time profiles and intensities of sub-THz bursts
Time profiles and intensities of sub-THz bursts
Time profiles and intensities of sub-THz bursts
Time profiles and intensities of sub-THz bursts
Types of Radio Spectra in microwave – sub-THz range
Types of Radio Spectra in microwave – sub-THz range
Types of Radio Spectra in microwave – sub-THz range
Types of Radio Spectra in microwave – sub-THz range
Types of Radio Spectra in microwave – sub-THz range
Types of Radio Spectra in microwave – sub-THz range
Types of Radio Spectra in microwave – sub-THz range
Types of Radio Spectra in microwave – sub-THz range
Different acceleration models give three basic predictions on the
Different acceleration models give three basic predictions on the
Different acceleration models give three basic predictions on the
Different acceleration models give three basic predictions on the
Different acceleration models give three basic predictions on the
Different acceleration models give three basic predictions on the
Different acceleration models give three basic predictions on the
Different acceleration models give three basic predictions on the
Different acceleration models give three basic predictions on the
Different acceleration models give three basic predictions on the
Suitable model:
Suitable model:
Suitable model:
Suitable model:
Suitable model:
Suitable model:
Suitable model:
Suitable model:
Suitable model:
Suitable model:
Electron distribution over length of the model loop for electron
Electron distribution over length of the model loop for electron
Magnetic field distribution is assumed to be B(s)=Bmin exp(-s2/sB2)
Magnetic field distribution is assumed to be B(s)=Bmin exp(-s2/sB2)
Magnetic field distribution is assumed to be B(s)=Bmin exp(-s2/sB2)
Magnetic field distribution is assumed to be B(s)=Bmin exp(-s2/sB2)
Magnetic field distribution is assumed to be B(s)=Bmin exp(-s2/sB2)
Magnetic field distribution is assumed to be B(s)=Bmin exp(-s2/sB2)
n0min=5 x 1010 cm-3 , n0max=1013 cm-3
n0min=5 x 1010 cm-3 , n0max=1013 cm-3
n0min=5 x 1010 cm-3 , n0max=1013 cm-3
n0min=5 x 1010 cm-3 , n0max=1013 cm-3
Razin-effect
Razin-effect
In plasma:
In plasma:
In plasma:
In plasma:
Gyrosynchrotron frequency spectrum in different parts of a flaring
Gyrosynchrotron frequency spectrum in different parts of a flaring
Gyrosynchrotron frequency spectrum in different parts of a flaring
Gyrosynchrotron frequency spectrum in different parts of a flaring
Gyrosynchrotron frequency spectrum in different parts of a flaring
Gyrosynchrotron frequency spectrum in different parts of a flaring
Total gyrosynchrotron frequency spectrum of the flaring loop
Total gyrosynchrotron frequency spectrum of the flaring loop
Bmin=400 G,
Bmin=400 G,
Bmin=400 G,
Bmin=400 G,
Influence of the free-free absorption on the sub-THz emission spectrum
Influence of the free-free absorption on the sub-THz emission spectrum
Influence of the free-free absorption on the sub-THz emission spectrum
Influence of the free-free absorption on the sub-THz emission spectrum
Influence of the free-free absorption on the sub-THz emission spectrum
Influence of the free-free absorption on the sub-THz emission spectrum
Картинки из презентации «Микроволновое и суб-тгц излучение вспышечной петли» к уроку физики на тему «Излучение»

Автор: Victor Melnikov. Чтобы познакомиться с картинкой полного размера, нажмите на её эскиз. Чтобы можно было использовать все картинки для урока физики, скачайте бесплатно презентацию «Микроволновое и суб-тгц излучение вспышечной петли.ppt» со всеми картинками в zip-архиве размером 657 КБ.

Микроволновое и суб-тгц излучение вспышечной петли

содержание презентации «Микроволновое и суб-тгц излучение вспышечной петли.ppt»
Сл Текст Сл Текст
1Микроволновое и суб-тгц излучение 14loop (Case of small plasma density in the
вспышечной петли. В.Ф. Мельников, ГАО РАН, lower parts of the magnetic loop). 2011.
Санкт-Петербург, Россия J.E.R. Costa, 14.
INPE, S.J. Campos, Brazil P.J.A. Simoes, 15n0min=5 x 1010 cm-3 , n0max=1013 cm-3.
CRAAM, Sao Paulo, Brazil. 7-я Ежегодная Gyrosynchrotron brightness and frequency
Конференция "Физика плазмы в spectrum in different parts of a flaring
солнечной системе" (6 - 10 февраля loop (Case of high plasma density in the
2012 г., ИКИ РАН). lower parts of the magnetic loop – strong
2Observations of flares in the 200-400 Razin effect). Low plasma density. High
GHz domain. 200-400 GHz measurements of plasma density. FP1 LT FP2. FP1 LT FP2.
flares have been obtained since year 2000: Due to the strong chromosphere heating
- routinely with SST at 212 and 405 GHz - during the flare energy release, the
short observing campaigns with KOSMA and plasma density in the lower parts of the
BEMRAK at 230, 345 and 210 GHz resp. loop can be strongly enhanced. 2011. 15.
Multi-beam observations at 210 GHz: 16Razin-effect. H(t) = rot A(t) E(t) =
estimate position and size of the radio -(1/c) ?A/ ?t - ?? Lienard-Wiechert
emitting region. About 15 major flares potentials: In vacuo: The potentials are
(GOES M3.2 - > X28) have been detected. closely connected with vectors of magnetic
2011. 2. and electric fields: e is the electron
3Time profiles and intensities of charge, and R is the radius-vector of the
sub-THz bursts. Sub-THz events occur in electron moving with velocity v taken at
strong X-class solar flares Their the retarded time t’ = t-nR/c. 2011. 16.
intensity in microwaves and sub-THz range 17In plasma: In a plasma, a refraction
reaches Ff = (1-10) 104 sfu They are long: index n =1 - fp2/ f 2 < 1 ? the
several munutes The time profiles at denominator can never be very close to 0,
sub-THz and microwaves are similar and even if v is close to c. So a relativistic
some seconds delayed against hard X-ray electron has an emission efficiency
time profiles. Kaufmann P. et al. Ap.J. comparable with a nonrelativistic one,
(2004), v603 L121-L124. 2011. 3. i.e. much lower than in vacuo. ? This
4Types of Radio Spectra in microwave – causes a strong suppression of radiation
sub-THz range. Normal extention of in the plasma, especially at lower
microwave spectrum. With sub-THz frequencies, f < fR=20n0/B (Razin,
component. SST. OVSA. Costa, Sim?es, 1960; Ramaty 1969; Klein 1987, Fleishman
Gim?nez de Castro. 4. & Melnikov, 2003). 2011. 17.
5Types of Radio Spectra in microwave – 18Gyrosynchrotron frequency spectrum in
sub-THz range. August 25, 2001. August 25, different parts of a flaring loop. Left
2001. April 12, 2001. GOES X5.3. GOES hand spectra are from the middle part of
X2.0. Costa, Sim?es, Gim?nez de Castro. 5. the loop Right hand spectra are generated
6So far: About 15 major flares (GOES from the lower parts of the loop. 17 GHz.
M3.2 - > X28) have been detected at 400 GHz. The frequency spectra of GS
frequencies 200, 400 GHz 7 to 8 normal emission coefficients from lower parts of
events reported Kaufmann et al 2001, 2002; the loop have the maximum near 400 GHz due
Trottet et al. 2002; L?thi et al. 2004a; to the Razin effect . 2011. 18.
Raulin et al. 2003, 2004; Cristiani et al. 19Total gyrosynchrotron frequency
2007a, 2010; Gim?nez de Castro et al. 2009 spectrum of the flaring loop. Frequency
5 THz events reported Kaufmann et al. spectra obtained by integration over the
2002, 2004; L?thi et al. 2004b; Silva et whole flaring loop for two moments of time
al. 2007; Cristiani et al. 2008. Trottet t1 and t2 on the rise phase of the burst.
et al, 2011. 2011. 6. Two spectral components in the microwave
7Sub-THz spectral component enigma: and sub-THz regions are clearly seen. The
emission mechanisms proposed. - microwave component shows an increase of
synchrotron radiation from positrons the peak frequency with time (due to the
emitted in pion or radioactive decay after self-absorption effect) The peak frequency
nuclear interactions (Trottet et al., for sub-THz component remains constant
2004) inverse Compton radiation (Kaufmann (due to the Razin effect). t2. t1. 2011.
et al., 1986) - gyrosynchrotron emission 19.
from a compact source (Kaufmann and Raulin 20Bmin=400 G, ? Bmin=100 G, n0max=1013
2006, Silva et al. 2007) - free-free cm-3 ? n0max=1012 cm-3. 2011. 20.
emission from an optically thick source 21Conclusions. The difficulties of
(Silva et al. 2007, Fleishman and Kontar, gyrosynchrotron interpretation associated
2010) - Cherenkov emission from with the unrealistically small size, large
chromospheric layers (Fleishman and non-thermal electrons number density ne,
Kontar, 2010) - synchrotron emission in and large magnetic field can be overcome
stochastic medium (Fleishman and Kontar, if the lower frequency turnover of the
2010) However, none of them can explain sub-THz spectral peak is caused by Razin
the full set of known properties of suppression. In this case, the only
sub-THz emission and its relations to requirement is a relatively high value of
other emissions like microwave, hard X-ray the Razin frequency: fR = 20 n0/B >=
etc. 2011. 7. 200 GHz. Such the value normally can be
8GS-interpretation of the sub-THz realized in the lower parts of flaring
spectral component. In this paper we loops. The large flux density of some
propose an idea that can solve the above sub-THz bursts, Ff ~ 104 sfu, associated
mentioned difficulties taking into account with X-class solar flares, is reached not
some recent findings concerning: the due to the large non-thermal electrons
importance of Razin suppression on the number density, but due to the large area
formation of observed gyrosynchrotron occupied by arcades (a large number of
spectra in microwave bursts; and the corresponding flaring loops) usually
spatial distribution of gyrosynchrotron present in such flares. 2011. 21.
emission generated by anisotropic fluxes 22Which observed properties of the
of accelerated electrons in inhomogeneous sub-THz emission can be explained by our
flaring loops. Silva etal (2007) have model? -- separate spectral peak at
shown that strong and well separated sub-THz; -- variability of the low
microwave and sub-teraherz spectral peaks frequency spectral index of sub-THz
can be explained by the gyrosynchrotron emission (alpha=1-6); -- presence and
emission of energetic electrons being absence of the separate spectral peak at
injected, respectively, into two sub-THz; (depends on specific conditions
interacting magnetic loops, one large with in a flaring loop); -- fast temporal
relatively weak magnetic field (microwave changes of the sub-THz intensity; -- time
source), another small with strong delays between microwave / sub-THz and
magnetic field (sub-THz source). However, hard X-ray time profiles. 2011. 22.
the source of sub-THz component has to be 23What properties of the sub-THz
extremely small (L<108 cm). It should emission we predict to be observed? --
also have very large magnetic field, brightness spatial distribution with
B>2000 G, and very high number density strong peaks near footpoints of flare
of non-thermal electrons, loops; -- the size of sub-THz sources can
n_e(E>50keV)>1012cm-3, in order to be large enough (no need to be too small,
be optically thick up to about 300-400GHz, like 0.5'', as for the simple GS
as well as to provide a sufficient mechanism); -- magnetic field strength can
instantaneous total number of electrons, be not too strong (>2000G) and number
N_t(E>50~keV)>5x1035, for fitting to density of nonthermal electrons should not
very high observed flux density, F_f to be too high (N(>50keV) ~ 1012cm-3 )!
~104sfu. 2011. 8. Future observations in sub-THz to THz
9Kinetics of Nonthermal Electrons in range are needed to check the validity of
Magnetic Loops. In a magnetic loop, a part these predictions. 2011. 23.
of injected electrons are trapped due to 24Needs of observations at higher
magnetic mirroring and the other part frequencies. ALMA? Space borne FIR
directly precipitates into the loss-cone. experiments Solar T: P. Kaufmann (PI)
The trapped electrons are scattered due to Golay cells for photometry at 45 ?m and
Coulomb collisions and loose their energy 100 ?m On NASA balloon with GRIPS (SSL
and precipitate into the loss-cone. A real Berkeley) Schedule: technical flight in
distribution strongly depends on the 2012-2013; long duration flight in
injection position in the loop and on the Antarctica in 2013-2014 DESIR: K.-L. Klein
pitch-angle dependence of the injection (PI) Arrays of microbolometers for
function S(E,?,s,t), and also on time photometry and source location at 35 ?m
(Melnikov et al. 2006; Gorbikov and and 100 ?m Laboratory studies; technical
Melnikov 2007, Reznikova etal, 2009). balloon flight Mission concepts. 2011. 24.
Non-stationary Fokker-Plank equation (Lu 25Thank you for your attention! 2011.
and Petrosian 1988): 2011. 9. 25.
10Parameters for our model simulations. 26Абстракт Предложен гиросинхротронный
For our simulations we take parameters in механизм одновременной генерации двух
the sub-THz source derived from спектральных пиков (микроволнового и
observations of the flare 2 November 2003 суб-терагерцового) радиоизлучения
(Silva et al 2007) that presents a good солнечных вспышек в рамках модели
example of the two simultaneously observed одиночной тонкой вспышечной петли.
spectral peaks, microwave at f ~ 15 GHz, Ключевым в модели является образование
and sub-THz at f > 200 GHz, both with повышенной концентрации релятивистских
high intensity Ff ~ 104 sfu. We assume электронов в нижней части петли, где
that the magnetic field is distributed соотношение плотности плазмы n0 к
exponentially along the loop: B(s)=Bmin магнитному полю B достаточно велико, чтобы
exp(-s2/sB2) with the mirror ratio частота Разина fR=20 n0/B достигала
Bmax/Bmin=2. Plasma density distribution значений fR ~ 200 ГГц. Установлено, что в
is chosen as: n0=n0min exp(s2/s12), where этом случае суб-терагерцовая и
s12= b_s2/ln(104), n0min=5 1010 cm-3, микроволновая спектральные компоненты
b_s=3 109 cm is the distance from the излучения генерируются в различных частях
center to the end of a loop. 2011. 10. вспышечной петли - вблизи оснований и в ее
11Different acceleration models give вершине, соответственно. Низкочастотная
three basic predictions on the position of часть суб-терагерцового спектрального пика
the acceleration site and pitch angle синхротронного излучения формируется за
distribution. счет эффекта Разина и ее источник является
12Suitable model: Pitch-angle оптически тонким. Последнее позволяет
distribution of injection function: In получить суб-терагерцовый пик излучения
this model a compact source of electrons как суммарное излучение от протяженной
is located at the loop top with the аркады вспышечных петель с общим размером
“beam-like” injection directed toward the до десятков угловых секунд. 2011. 26.
left foot. Left FP. 2011. 12. 27Initial and boundary conditions. .
13Electron distribution over length of (35). 2011. 27.
the model loop for electron energy E=405 28Injection function: . (35). 2011. 28.
keV and for two values of pitch-angles In 29Influence of the free-free absorption
the case of beamed injection of on the sub-THz emission spectrum. Sub-THz
accelerated electrons from the loop top gyrosynchrotron spectral peak has been
region, we can get a strong peak of the disappeared! Instead, we obtain a
electron number density near the significant free-free emission spectral
footpoints where the magnetic field is increase! 17 GHz. 400 GHz. Plasma density
also strong. The upper plot shows the distribution is the same, as for the
distribution for electrons rotating almost previous case Temperature distribution is
perpendicular to the magnetic field lines, homogeneous, T = 107 K. 2011. 29.
with pitch-angle 89.36o. The lower plot is 30As we can see, free-free emission
for electrons propagating along field itself can be very important for producing
lines with small pitch-angle 12.17o. 2011. sub-THz spectral component. This can
13. happen in the case of strong chromospheric
14Magnetic field distribution is assumed evaporation in the lower part of flaring
to be B(s)=Bmin exp(-s2/sB2) with the loops. Note, however, that the influence
mirror ratio Bmax/Bmin=2 The peak of of the free-free absorption on the
non-thermal electrons near the footpoints gyrosynchrotron sub-THz spectral peak can
can easily produce strong radio emission be strongly decreased if we: make the
at frequencies up to THz range. However, temperature distribution more homogeneous
even in this case, the spectral maximum is along the loop decrease the plasma density
located at frequencies much less than 400 and, in parallel, decrease the magnetic
GHz under all reasonable parameters of field strength in the loop The last two
non-thermal electrons and magnetic field! conditions make the Razin frequency almost
Gyrosynchrotron brightness and frequency unchanged: fR=20n0/B ~ const. 2011. 30.
spectrum in different parts of a flaring
Микроволновое и суб-тгц излучение вспышечной петли.ppt
http://900igr.net/kartinka/fizika/mikrovolnovoe-i-sub-tgts-izluchenie-vspyshechnoj-petli-98539.html
cсылка на страницу

Микроволновое и суб-тгц излучение вспышечной петли

другие презентации на тему «Микроволновое и суб-тгц излучение вспышечной петли»

«Спектр излучения» - Полярное сияние, рекламные трубки. КПД хемилюминесценции составляет 1–30%, а биолюминесценция достигает 100% (у светляков). Исследуются такие спектры с помощью прибора спектрофотометра. Спектроскопия. Спектры испускания: 1- сплошной, 2- натрия, 3- водорода, 4-гелия. Ярко светящаяся поверхность Солнца - фотосфера - дает непрерывный спектр.

«Тема Виды излучений» - Рентгеновские лучи. Ионизирует воздух. Ультрафиолетовое излучение. Инфракрасное излучение Ультрафиолетовое излучение Рентгеновское излучение. Рентгеновская фотография (рентгенограмма) руки своей жены, сделанная В. К. Рентгеном. Инфракрасное- «тепловое» излучение. Медицина Рентгеноспектрометр Дефектоскоп.

«Излучение и спектры» - Непрерывный спектр. Спектры, И виды излучения. Эмиссионный спектрометр. Католюминесценция. Электролюминесценция. Полосатый спектр состоит из отдельных полос, разделённых темными промежутками. Перейти к содержанию. Содержание. Лабораторная электролизная установка для анализа металлов «ЭЛАМ». Перейти к схеме.

«Радиоактивное излучение» - Сравнение проникающей способности излучений разных типов. Радиоактивные излучения. Радиоактивное излучение может сыграть злую шутку против своих же основателей, которые могут и должны выполнить все действия для ослабления влияния ядерного оружия на глобальную политику и экономику.

«УФ излучение» - Интенсивное УФ излучение непрерывного спектра испускают электроны в ускорителе. Более мощный источник Ультрафиолетового излучения – любая высокотемпературная плазма. Входящими в состав стекла. Взаимодействие излучения с веществом. Биологическое действие Ультрафиолетового излучения. Ультрафиолетовые лучи,УФ излучение.

«Излучения» - Критерии оценивания. Как влияют электромагнитные излучения на человеческий организм? Визитка проекта. Оригинальность – донести теоретический и физический смысл влияния излучений на человека. Ожидаемый результат. Учебно-методический материал. Презентация учителя. Актуальность и оригинальность проекта.

Излучение

10 презентаций об излучении
Урок

Физика

134 темы
Картинки
900igr.net > Презентации по физике > Излучение > Микроволновое и суб-тгц излучение вспышечной петли