# Presentation: 051929

## The Plasma and SupraThermal Ion Composition (PLASTIC) Instrument: Final Diagnostic Development Phase for the STEREO Mission

- _L. M. Blush_1, P. Bochsler1, H. Daoudi1, A. Galvin2, R. Karrer1, L. Kistler2, B. Klecker3, E. Möbius2, A. Opitz1, M. Popecki2, B. Thompson5, R. F. Wimmer-Schweingruber4, P. Wurz1

*1** Physikalisches Institut, University of Bern, Switzerland*
*2** University of New Hampshire, Durham, NH, USA*
*3** Max-Planck Institut für Extraterrestrische Physik, Garching, Germany*
*4** Institut für Experimentelle und Angewandte Physik, University of Kiel, Germany*
*5** Goddard Space Flight Center, Greenbelt, MD, USA*

- The PLAsma and SupraThermal Ion Composition (PLASTIC) instrument project is entering the final phases of instrument development prior to integration with the Solar Terrestrial Relations Observatory (STEREO) spacecraft in early 2005. The STEREO mission will provide a unique opportunity to investigate the 3-dimensional structure of the heliosphere, with particular focus on the origin, evolution, and propagation of Coronal Mass Ejections (CMEs). The mission also seeks to determine the sites and mechanisms of energetic particle acceleration as well as develop a 3-D time-dependent understanding of the ambient solar wind properties. As one of four STEREO instrument packages coordinating remote sensing and *in situ* measurements, the PLASTIC instruments will diagnose properties of the solar wind and suprathermal protons, alphas, and heavy ions. PLASTIC will determine bulk solar wind plasma parameters (density, velocity, temperature, temperature anisotropy, and alpha/proton ratio) and the distribution functions of major heavy solar wind ions in the energy per charge range 0.25-100keV/e. A full characterization of the solar wind and suprathermal ions will be achieved with a system that measures ion energy per charge (*E/q*), ion velocity distribution (v), and ion energy (*E*). Two identical PLASTIC instruments located on the separate spacecraft will provide *in situ* plasma measurements in order to study physical processes low in the corona and in the inner heliosphere. Elemental and charge state abundances provide tracers of the ambient coronal plasma, fractionated populations from coronal and heliospheric events, and local source populations of energetic particle acceleration. In this presentation, the PLASTIC operation principles and aims will be presented along with a review of development status and current instrument calibration results.

- Abstract

- The STEREO/PLASTIC Instrument

- PLASTIC Measurement Principle

- PLASTIC FM1 prior to shipment from UNH to University of Bern for detailed ion beam calibrations

**TOF Mass & M/Q Spectrometer**
*Simplified Principle of Operation*** **
**        ****E/Q, ****TOF ******** M/Q**
**        ****TOF, ** **E**meas ****** M**

*PLASTIC Mass Spectrometry Principle*

- Entrance System Ion Beam Calibrations
- in the UBern CASYMS Facility

*The PLASTIC instrument response can be simulated by utilizing instrument parameters and sub-system calibrations*

- Future work will entail refinements to the instrument response, with better instrument parameters and further testing of sub-system operation.
-   SSD response to full range of ion species
-   C-foil SEE, ion scattering

- Paper Number: SH21B-0410

- PLASTIC Instrument Sub-Systems Overview

*The development and detailed testing of instrument sub-systems is necessary to meet the delivery schedule and enhances the understanding of full instrument operation*

- Entrance System Ion Optic Calibration

- Special acknowledgement to J. Fischer, J. Jost, M. Sigrist, A. Etter, and the extended University of Bern team as well as M. Granoff and many others of the University of New Hampshire PLASTIC team.
- This work is supported by the Swiss National Fund and PRODEX Grant C90119.

- Solid-State Detector Ion Energy Measurements

*Energy defect is needed to interpret solar wind (and suprathermal) ion response of the SSD *
*(Canberra PIPS 25nm Si entrance window)*

*Measurement of Ion Energy Response*

- Measurements in MEFISTO Beam Facility compared
- with a LSS analytic model of energy response

- E-Box containing operation and command electronic and power supplies

*Analyzer & Deflection Constants*

- A relation between applied electrode voltages and selected energy as well as selected angle is need to set flight operation value and interpret measurements

- Time of Flight - Integrated Instrument Calibrations

*Deflection & E/q Sweep Operation*

*Anode Localization of Start Pulse*

*Energy & Time of Flight Measurements*

- PLASTIC FM1 Instrument
- in CASYMS Facility

- PLASTIC M-M/Q Matrix

- Instrument Response Simulation