2. History

5. Compilation of the primary CR energy spectra J. R
Compilation of the primary CR energy spectra J.R.Hoerandel, astro-ph/

6. Single Source Model
of the Knee

9. Single Source Model (SSM)
Basic ground of SSM is the non-uniform distribution of CR sources (SN and SNR) in space and time.
The probability of the relatively recent (<105y)
SN explosion in the vicinity of the Sun (<300pc)
is rather high (~1)

11. S does not depend on absolute values of I and g

12. Sharpness of the knee at different atmospheric depths
Galactic Modulation
GALACTIC MODULATION

13. Due to the stochastic nature
of CR sources there must be
‘structure’ in the CR energy
spectrum at some level …
Wolfendale A.W.

14. Fine Structure of the KneeFe
in the ‘Single Source Model’
In ‘Single Source Model’
in Cherenkov light spectra
in EAS size spectra
knee

15. Single Source Model
( basic idea )

17. me, Baksan
me, SYB zm
me, QGS mh
mhe

18. General Conclusion
Sharpness of the knee and fine structure of the CR energy spectrum manifest the substantial role of the non-uniform distribution of CR sources in space and time. They point out at the dominant contribution of the nearby and young SNR in the knee region. As a candidate for this ‘single source’«одиночного can be SNR Monogem Ring with the pulsar B

19. LHC and the Origin of the Knee

20. ALICE shows what is above the knee

21. ALICE shows what is above the knee

22. Conclusion
The knee is not due to the change of the interaction characteristics of cosmic ray particles with air nuclei

23. Possible Single Source

26. Vicinity of the Sun (nearby 300 pc)

28. Vela SNR
June 12,                                                           
pulsar B & Vela X PWN
Vela Jr

30. Do we see an ‘Iron Peak’ ?

31. GAMMA-2008: event-by-event analysis

32. TUNKA - 133

33. IceTop

35. of the contribution from the Single Source
We think that the steepening of the spectrum at 1017eV indicates the end
of the contribution from the Single Source

36. Anisotropy

38. EAS intensity excess at PeV energies G. Benko et al
EAS intensity excess at PeV energies G.Benko et al., astro-ph/ , Изв.РАН, сер.физ.,2004, 68, 1599;
Monogem Ring

42. Conclusions on the anisotropy
At logE,GeV < 5 the data on the anisotropy are consistent and surprisingly indicate the excess from the Outer Galaxy ( 3rd quadrant ). Possible explanation is the random configuration of nearby sources.
At logE,GeV > 5 both the amplitude and the phase change their energy dependence. Excesses move towards the Inner Galaxy ( 4th quadrant )

43. Puzzles of the PeV region
around the Knee

44. ‘Neutron thunder’

45. Neutron monitor counting rate, II
I, ms-1
1000
2000
3000
Delay t, ms

46. PeV energy region
Findings ( Antonova V.A. et al., 2002, J.Phys.G, 28, 251 ):
1. There are a lot of neutrons delayed by hundreds of ms after the main shower front (‘the neutron thunder’). Their temporal distribution is different from the standard one in neutron monitors.
2. Distortions of the temporal distributions seem to have a threshold and begin in the PeV (‘knee’) region.
3. Multiplicity of such neutrons is very high compared with EAS model expectations.
4. These neutrons are concentrated in the EAS core
region.
5. Delayed neutrons are accompanied by delayed gamma-
quanta and electrons.

47. Conclusions for PeV energies
1. The bulk of observed neutrons are not born in the
shower. They are produced inside the neutron monitor.
2. Their temporal distribution is the standard monitor distribution, distorted by the saturation of the counting rate at high neutron fluxes.
3. The distortions start at the threshold when the counting rate reaches the saturation level.
4. The very high multiplicity of produced neutrons and their concentration near the EAS core are due to the
narrow lateral distribution of EAS hadrons and their energy around the core.
5. Delayed gamma-quanta and electrons have also a secondary origin – they are produced by delayed neutrons in the detector environment.

48. Temporal distribution of eg, m and n at different EAS core distances
After 5ms
at the core distance of 1km neutrons
are the
dominant component
of the shower
R<10m
R=100m
R=1000m
Time, ms or ms

49. General remarks
The discovery of ‘the neutron thunder’ by Chubenko A.P. with his colleagues is an outstanding achievement .
If our interpretation of it is correct, this phenomenon extends our understanding of the EAS development and its interaction with detectors and their environment.
The study of EAS neutrons is complementary to the study of other EAS components by Geiger counters, scintillators, ionization calorimeters, gamma-telescopes, X-ray films etc. and all together they could give the full picture of atmospheric shower.

50. The phenomenon of ‘the neutron thunder’ emphasizes the role of detectors and their environment in the observed signals. The surrounding materials containing water could increase the neutron scattering, moderation, and production of secondary gamma-quanta and electrons. In this aspect, mountain studies can be particularly vulnerable. Mind that the EAS core at mountains as the neutron generator carries much bigger energy than at sea level. As for the environment, a good part of the year mountain stations ( viz. Tien-Shan, Aragats, Antarctic etc.) are covered by snow sometimes of meters thick.
As for the Tien-Shan station, there might be an additional factor emphasizing the role of neutrons – its ground is a permafrost containing a good fraction of ice.
There might be effects at shallow depths underground
connected with the propagation of neutrons produced
when the EAS core strikes the ground.

51. EAS-TOP in winter

52. Aragats in the spring

53. Aragats,
May 2006

54. IceTop

55. 3. The water cherenkov detectors are particularly worth of
attention. First of all water as hydrogen containing stuff
is a moderator like a polyethilene of the neutron monitor.
Secondly it might be sensitive to secondary electrons and
gamma-quanta, produced by neutrons interacting with
water ( mind the discovery of cherenkov radiation itself ).
Since water and ice cherenkov detectors are wide spread
all over the world ( MILAGRO, NEVOD, ICE-TOP ) and in
particular used in Pierre Auger Observatory, the
contribution of neutrons at large core distances and ms
delays might be noticable and needs a special study.
4. The same remark is relevant for large EAS, based on
hydrogen containing plastic scintillators ( Yakutsk,
Telescope Array ).

56. Delayed particles in the EAS front

57. Mean τ and σ of particles in the EAS front

58. in experiment and simulations
Averaged ‹Τ› and Σ vs R
in experiment and simulations

59. Fine structure of the EAS front
(‘double showers’ ?)

60. Mean τ vs σ of particles in the EAS front
experiment
simulation

61. CONCLUSIONS
There are more things in heaven and earth, Horatio, than are dreamt of in your philisophy…
W.Shakespeare, Hamlet

62. “… The only malady I could conclude I had not was housemaid knee.
I felt rather hurt about this at first;
It seemed somehow to be a sort of slight.
Why hadn’t I got housemaid knee ?
Why this invidious reservation ?…”
Jerome K. Jerome “Three men in a boat.
To say nothing of the dog”