1. BepiColombo Mercury Dust Monitor ( MDM ) P.1 BepiColombo MMO Payload Mercury Dust Monitor (MDM) MMO Science Working Sub-Group Meeting At Kyoto Univ. 22 March 2006

2. BepiColombo Mercury Dust Monitor ( MDM ) P.2 Metal (Mg) frame of the PZT sensor (same as the flight model) PZT Mg Frame

3. BepiColombo Mercury Dust Monitor ( MDM ) P.3 (5cm x 5cm) x 4 plates of PZT fixed in the frame

4. BepiColombo Mercury Dust Monitor ( MDM ) P.4 New big chamber on the dust beam line at HIT accelerator 700 mm Dust beam sensor

5. BepiColombo Mercury Dust Monitor ( MDM ) P.5 (5cm x 5cm) x 4 plates of PZT in the chamber

6. BepiColombo Mercury Dust Monitor ( MDM ) P.6 Installation of MDM and heat flow To be fixed * How to fix the 4 cables. * connector * hole size * cable length (< 20 cm ) * insulator and heat conductor

7. BepiColombo Mercury Dust Monitor ( MDM ) P.7 Local sensitivity of the 5cm sq. PZT Output voltage of the PZT Output electrode Exited points by the needle.

8. BepiColombo Mercury Dust Monitor ( MDM ) P.8 Green/PMT, Blue/ ③, Red/ ② ④ ③ ② ① ビーム ２ ４ １ ２ ６ 50 mm Typical signals from different part of the PZT Iron particle: 2.56km/s 45.7pg To be fixed : optimum electrode and PZT size

9. BepiColombo Mercury Dust Monitor ( MDM ) P.9 Momentum vs. Output Vp ( different area of the PZT ) Momentum ( pg km/s ) Vp ( mV )

10. BepiColombo Mercury Dust Monitor ( MDM ) P.10 Output by different types charge sensitive amplifier ( to be fixed ) Amp1 (Clear Pulse) Amp2 (Ampteck) Momentum ( pg km/s ) Output Vp (mV)

11. BepiColombo Mercury Dust Monitor ( MDM ) P.11 High temperature endurance test of PZT 、 ２００℃、 ２５ｄａ ｙｓ

12. BepiColombo Mercury Dust Monitor ( MDM ) P.12 Change of the signal shape with impact velocity 5.1km/s 19pg 6.3km/s 7.0pg8.4km/s 4.5pg 20km/s 36fg (C) (A)(D) (B) Category I Category II Category III

13. BepiColombo Mercury Dust Monitor ( MDM ) P.13 PZT Thickness Rise time vs. velocity of single peaked pulse High speed impact ( > 8 km/s )

14. BepiColombo Mercury Dust Monitor ( MDM ) P.14 Restructured signal form with different frequency range Original output shape High frequency comp. Low frequency comp.

15. BepiColombo Mercury Dust Monitor ( MDM ) P.15 おわり ( End ) 10 min

16. BepiColombo Mercury Dust Monitor ( MDM ) P.16 Present status Now checking the thermal resistance of the using parts. － 200 ℃ ～ 250 ℃ Piezo electric sensor Sensitivity Long time stability Flexible insulation material Experiment using the Dust accelerator at Max Plank Institute, Germany 4 weeks at November 2005

17. BepiColombo Mercury Dust Monitor ( MDM ) P.17 Result of thermal analyses 10c m PZ T Mg Frame ●PZT Sensor 100 cm 2 5cm x 5cm x1 mm, 4Plates ● Solar Radiation 14 kW/m 2 10 x Solar Constant ● PZT Thermal constant Surface metal plate (Ag) ● Mg Frame ( white paint ) α=0.2, ε=0.8 ● Thermal conductivity (W/mK) PZT: 1.0, Frame: 43.6

18. BepiColombo Mercury Dust Monitor ( MDM ) P.18 MDM master schedule

19. BepiColombo Mercury Dust Monitor ( MDM ) P.19 Local sensitivity of the PZT (Mechanically Exited) 電極１ 電極２ 電極３ 電極４ 5cm

20. BepiColombo Mercury Dust Monitor ( MDM ) P.20 Momentum vs. velocity from the restructured signal ( high frequency ) momentum ( pg km/sec ) velocity ( km/sec )

21. BepiColombo Mercury Dust Monitor ( MDM ) P.21 Rise time vs. velocity from the restructured signal ( Low frequency ) Velocity ( km/sec ) Rise time ( n sec )