Erwin O. Flückiger Physikalisches Institut University of Bern erwin.flueckiger@space.unibe.ch

1. Cosmic Rays and Neutron Monitors -A training course in science and applicationsSeptember 14-19, 2009Athens, Greece–Introductory Overview Erwin O. Flückiger Physikalisches Institut University of Bern erwin.flueckiger@space.unibe.ch

2. The World of Cosmic Rays(CR) Discovery attributed to Victor Hess1912

3. Terms extragalactic, galactic, solar, and anomalous cosmic rays refer to different components with respect to their origin primary CR: at the top of the Earth’s atmospheresecondary CR: produced in the Earth’s atmosphere

4. What are CRs? Galactic cosmic rays Protons (87%), nuclei of helium (12%), and, in diminishing amounts, of carbon, oxygen, etc., and of heavier elements. All are fully ionized. Electrons account for about 1% of the cosmic rays. Neutrons, Neutrinos and Tau-particles are the representatives of a very special component. With a few exceptions, the chemical composition of cosmic ray nuclei corresponds to the elemental abundances in our solar system.

5. The life of a GCR particle • Birth • Escape • Acceleration • Transport in the galaxy • Interaction with solar wind • Interaction with the Earth’s magnetosphere • Interaction with the Earth’s atmosphere • Death (e.g. in a detector)

6. Energy density of CR in interstellar space • 2.7 K background radiation ~ 0.25 eV/cm3 • Starlight ~ 0.5 eV/cm3 • Magnetic fields ~ 1.2 eV/cm3 • Kinetic energy of interstellar material ~ 0.3 eV/cm3 • Cosmic radiation ~ 1.2 eV/cm3

7. ACE, GOES… AMS, BESS, PAMELA, … Special Detectors ~ E-2.6 Neutron Monitors ~ E-3.2 AUGER, … Muon Telescopes ~ E-2.6 Galactic and Solar Cosmic Rays Flux: ~35 orders of magnitude/ Energy: ~ 14 orders of magnitude ⇒ requires different observing techniques

8. NMDB • Neutron Monitors NMs - cover only ~ 1.5 of the more than 12 orders of magnitude in the energy spectrum • But cover energy region that • - includes solar modulation of GCR, • - contains sporadic solar cosmic rays, and • - has most important effects on Earth • Are the prime instruments for CR research in the low GeV region • Have longest series of CR measurements in history (since 1956) ⇒ NMDB

9. Worldwide / NMDB Neutron Monitor Network

10. 1991-2001 Solar Modulation of Galactic Cosmic Rays

11. The 13 December 2006 Solar Particle EventNeutron Monitor Observations

12. CR Effects: the 20 January 2005 Solar Particle EventAtmospheric Ionisation at 250 g cm-2

13. NMDBtraining course in science and applications • key lectures and lab courses by leading experts in the field on • origin (galactic and solar) • propagation (in the inter-planetary medium and in the Earth’s magnetosphere) • interactions with the Earth's atmosphere and environment • the Heliosphere and galactic cosmic rays (modulation) • Solar Cosmic Rays (GLEs) • Scientific & technical back-ground of Neutron Monitors • New technologies for CR detection • CR effects (CR and climate), Space Weather, and • the use of NMDB !

14. NMDBtraining course in science and applications---we wish youboth a profitable and enjoyable time!