FUTURE OBSERVATIONS OF THE OUTER HELIOSPHERE M. Hilchenbach and H. Rosenbauer Max-Planck-Institut für Aeronomie, D Katlenburg-Lindau, Germany

NASA 1964 Frisch 2000 outer heliosphere....the next frontier

Based on Frisch 2000 Observables

Fisk 1996 Woch 1997 Axford Suess 1994 Sun - Heliosphere

Keppler 1998 Leske 2000 Anomalous Cosmic Rays Charge State Determination based on Dichter 1990 via earth’s magnetic field

Micro-Calorimeter Stacks will be used for the Advanced Cosmic-Ray Composition Experiment for the Space Station (ACCESS 2005)

Russel Ion Detectors

Neutral Hydrogen Solar and Interstellar Kohl 1998 SOHO SWAN 1999

Gruntman 1997 Principles of Neutral Particle Detection

Neutral Particle Detectors ASPERA-3 Mars Express 2003 Cheng 1993 MENA IMAGE 2000

Neutral Particle Detection Efficiency from Gruntman 1997 Barat 2000 H -

Interstellar Helium Detector Witte 1992 Witte 1999 NIHEAD Interplanetary Pathfinder 1998

Borovik 2000 Schwarz-Selinger 2000 Denier van der Gon 2000 Surface conversion and detection Metastable atoms H

Gruntman 1997 Doak 1999 Wave properties of photons or atoms focussing of ‘cold atom beam’ UV Suppression

Morozov 1999 Time-of-flight analyzer with a floatable drift tube Simultaneous energy distribution and ion/neutral fraction measurements using a linear time-of-flight

Hadamard transform time-of-flight mass spectrometer Brock 1999 High duty cycle: about 50%

Clemmons 1998 Mass spectroscopy using a rotating electric field time-of-flight phase E

Funsten 1996 E B Energy-Mass Spectrograph for Measurement of Ions and Neutral Atoms

Vickers 1999 Silicon Anode Detector (CCD)

Keller 1999 A Capacitance Standard Based on Counting Electrons Temperature 40 mK ‘Quantum dots’

Ion Propulsion System Possible ionisation of interstellar atoms of the LISM DS1 1998

SOHO LASCO C Space and Time

2 D Pictures : Example SOHO LASCO C1 Inhester 1998

Model and Observation: Example Inhester 2000

Tools: Photons and Neutral Atoms* *Trajectories are ballistic orbits, for energetic neutrals far off the sun a straight line is appropriate. Towards a 3D Picture Stereoscopy (and Tomography)

Based on Inhester 2000 Stereoscopy of “heliospheric” objects (I) - an overdetermined problem- a well determined problem point-like objectsline objects

Stereoscopy of “heliospheric” objects (II) ambiguities of a single line multiple crossings of the epipolar plane position error The error is proportional to pixel size / sin (  /2), where  is the angle between projection surface normals at intersection. The error is particular large at the line tops.

Stereoscopy of “heliospheric” objects (III) ambiguities for line systems Multiple solutions if a unique correspondence between individual lines in the two images cannot be found Surfaces and clouds - an underdeterminded problem Additional constrains, e.g. assumption of a curvature radius R in the epipolar plane can help.

Stereoscopy vs tomography Fundamental assumption in stereoscopy: Emission from a single spot along line of sight - a second view is sufficient to determine d. Generalisation in tomography: Emission distributed along line of sight - a large number of other views required to resolve F(d). - not possible from the inner heliosphere….

ambiguities for line systems can be resolved Coincidence measurement requires good detection efficiency. Events resolved in time and angular space Fluctuations in time Observations including the event timing tAtA v A * t A v B * t B Inversion from inner helio- sphere possible ? A B C observed f(t) along line-of-sight

View beyond the heliosphere (about 250 years ago)

Stereoscopic (and Tomgraphic) Observations of the Outer Heliosphere Observables in the Inner Heliosphere - Photons - Energetic Neutral Atoms - Solar wind, Pick-up ions, Cosmic Rays Requirements: - Models of Global and Local Structures in Space and Time - Multispacecraft observation with Resolution in 2D Space and Time - High efficiency and resolution instruments (Coincidence Measurements) The Next Frontier

Marckwordt 2000 MCP Detectors and Friction