1. MuSTAnG – Muon Spaceweather Telescope for Anisotropies at Greifswald * Poster Content Space Weather Physics behind Cosmic Ray Muon Anisotropy MuSTAnG Consortium and Status of Construction MuSTAnG in the International Muon Telescope Network F. Jansen 1,2 and R. Hippler 1 1 University of Greifswald, Institut for Physics, Domstr. 10a, 17489 Greifswald, Germany 2 1A - First Applications and Management Consultancy for Space Weather Service, Research, Education and Culture, Markt 15-19, PF 3119, 17461 Greifswald, Germany jansen@physik.uni-greifswald.de and hippler@physik.uni-greifswald.dejansen@physik.uni-greifswald.dehippler@physik.uni-greifswald.de *ESA/ESTEC contract 18835/04/NL/MV

2. 10 hours before SSC Space Weather Physics behind Cosmic Ray Muon Anisotropy: First Observations Sun direction Example: space weather storm on 9th September 1992 (Figures right (from top to bottom, black line is the sudden commencement (SSC) ) 1) change of Kp index versus time 2) cosmic ray neutron monitor counts versus time (no hints for changing counts rate before SSC) 3) pitch angle versus time, but with cosmic ray muon telescope data (Nagoya Scintillator Telescope) enhancement of comic ray muon anisotropy into Sun direction (black circles) about 10 hours before SSC 4) change of interplanetary field magnitude 5) change of solar wind velocity Details see in Munakata et al. J. of Geophys. Res. 105 (A12) 27457, 2000

3. Space Weather Physics behind Cosmic Ray Muon Anisotropy: Physics behind the Muon Anisotropy 1) Ground-level CR detectors scan various directions in space (including to the Sun) as Earth rotates. 2) Daily variations in counting rates on ground reflect anisotropic intensity distribution of cosmic rays in space. 3) Semidiurnal variation due to interactions in the heliosphere of outward moving solar wind and inward diffusing galactic cosmic rays. 4) Semidiurnal variations were observed by neutron monitors, ion chambers and muon telescopes. 5) Detectors observe reduced flux of CR particles moving away from the shock (with small pitch angles), due to CR depleted region behind the shock. 6) CR intensity deficit or increase in the order of 1 % to 4 % (PAD – Precursor Anisotropy Decrease, PAI – Precursor Anisotropy Increase). 7) First detection of the shock at a distance of r ~0.1 λ P cos ß (λ P scattering mean free path of cosmic rays, angle between Sun-Earth line and the mean IMF at Earth) 8) λ P about 1 AU for 10 GeV CRs (neutron monitor energy range) => 5 hours before shock wave arrival 9) Muon telescopes measure at 50 GeV => λ P much longer => 24 hours before shock wave arrival !!!

4. Space Weather Physics behind Cosmic Ray Muon Anisotropy: Sketch of Physics

5. MuSTAnG Status, the Consortium* University of Greifswald: F. Jansen, R. Hippler 1A Greifswald / Germany: F. Jansen, G. Bartling IEPSAS Kosice / Slovakia: K. Kudela AAD Hobart / Australia: M. Duldig, J. Humble University of Bern / Switzerland: E. Flückiger HTS Dresden / Germany: W. Göhler, S. Brunner Shinshu University / Japan: K. Munakata UAS Stralsund / Germany: G. Kolbe, B. Zehner Hanse city of Greifswald / Germany *ESA/ESTEC contract 18835/04/NL/MV

6. MuSTAnG Status: Telescope Principles Detection / construction principle: - two layers (8 sqm) of plastic scintillators (PS) with wavelength shifter, lead layer (4 sqm) between the PS layers for low energy CR absorption - high voltage photomultiplier tubes for signal detection and direction determination due to coincidence measurements at different plastic scintillator plates - electronics and data recording Schedule: - start of construction January 2005 - current status: development and order of hardware, electronics and software - data available summer 2006 Scintillator Optical coupling Light amplification Data acquisition Incoming Muon

7. MuSTAnG Status: Layout 4m 2 prototype: 2m x 2m, 2 detector layers: 8m 2, 1 lead layer: 4m 2 entire height about 2m readout electronics: wavelength shifter and 8 PMTs entire weight: 3 t

8. MuSTAnG in the International Muon Telescope Network  MuSTAnG becomes part of the international European -Australian – Japanese – Brazil muon telescope network  Australia: MPC (Mawson Propotional Counter), HST (Hobart Scintillator Telescope, 18 sqm detector size) Japan: NST (Nagoya Scintillator Telescope, 72 sqm detector size) Brazil: SMST (San Martinho Scintillator Telescope, 8 sqm detector size)  Part of SWENET and COST 724 data (WG2, WG4)

9. MuSTAnG in the International Muon Telescope Network: Asymptotic Viewing Directions of Network Telescopes - a nearly full coverage (and therefore a 24 hour observation of CME - propagation) is possible, - 20 to 24 hours forecast of CME arrival time is expected + 54° MuSTanG + 35° NST - 29° SMST - 43° HST

10. MuSTAnG in the International Muon Telescope Network: Equation for Muon Data Abbreviations - jth telescope (for example j=1 MustAnG...), with ith detector at the different geographical locations, - t is UT, t i is the local time of the ith detector, - s and c are the „coupling coefficients“: function of primary CR spectrum, observed muon flux (cph as function of zenith and azimutal angles) including asymptotic viewing directions, telescope response function (telescope specifics) - I 0 (t) isotropic CR component (eg. yearly mean) and - ξ x GEO, ξ y GEO, ξ z GEO anisotropy vectors in geographical coordinate system First step of solving the equation ξ x GEO, ξ y GEO, ξ z GEO geographical coordinate system, and than... The aim is to find a best-fit calculation I i,j cal (t) for the observed CR muon density I i,j obs (t) Munakata et al.,Adv.Space Research 2005, in press

11. MuSTAnG in the International Muon Telescope Network: Solving the Equation for Muon Data - next steps: a) coordinate transformation from ξ x GEO, ξ y GEO, ξ z GEO to ξ x GSE, ξ y GSE, ξ z GSE geocentric solar ecliptic system (ξ x and ξ y (ecliptic plane anisotropy vectors), ξ z – north / south anisotropy vector) => result I i,j cal (t) in GSE system and b) consideration of solar wind convection caused anisotropy (different solar wind speed, real time ACE s/c data) and c) consideration of anisotropy due to Earth‘s orbital motion around the Sun (30 km/s, Compton-Getting anisotropy) FINAL RESULT OF NUMERICAL SOLUTION best fit anisotropy vector ξ x, ξ y, ξ z and I i,j obs (t) in GSE coordinate system