Launch: March 2, 2004
The ROSINA-DFMS flight model. Credits ...
In 1993 the Science Program Committee of ESA approved the ROSETTA mission as a planetary cornerstone mission of its long-term science program. The ROSETTA spacecraft fulfilling this mission was launched in 2004 and performed a rendezvous with comet 67P/Churyomov-Gerasimenko, after a swing-by of planet Mars and two asteroid flybys.
Layout of the DFMS instrument. Credits ..
One of the instruments selected for this mission was the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA), part of which was the Double Focusing Mass Spectrometer (DFMS). During the feasibility study for the ROSINA DFMS magnetic mass spectrometer, the need arose for a focal plane ion detector having a large sensitivity range and being capable of recording simultaneously a series of ion mass peaks with high mass resolution.
Rosetta spacecraft with Rosina-DFMS in the top right corner. Credits ...
The device consists of a focal plane array for the recording of positive ion mass spectra, in combination with a stack of two Micro-Channel Plates (MCPs) mounted in front of it. The adjustable ion to electron conversion gain of the MCP stack realizes the desired variable sensitivity, while the analog charge collection and read-out system in the chip is responsible for the collection of the MCP output charge with high spatial resolution, low noise, and large dynamics range.
DFMS installed on the vibration table. Credits ...
Only a few detector types fulfill the requirement of combining widely adjustable MCP gain and the simultaneous recording of ion spectra over a wide sensitivity range and high spatial resolution. However, those devices do not comply with other requirements like circuit redundancy and on-chip integration of analog read-out electronics. Therefore, a new detector chip was designed in standard Complementary Metal–Oxide–Semiconductor (CMOS) technology.
The chip integrates two identical but independent detector units, each composed of a row of 512 separate floating anodes, an analog multiplexer addressed by a shift register, a voltage reference, and a charge sensitive amplifier. The chip is named LEDA512, which stands for Linear Electron Detector Array with 512 anodes.
The DFMS detector with its Remote Detector Pack (RDP) electronics (top left), the LEDA detector (top right), one board of the RDP (bottom left), one board of the Floating Detactor Pack (FDP) electronics (bottom right). Credits ...
A stack of two MCP devices is mounted in close proximity in front of the chip surface. The MCPs emit an electron cloud each time the front of the stack is hit by an impinging ion. The impact position of this ion is selected by the mass spectrometer according to its mass-to-charge ratio. The electrical field applied between the MCP back and the chip guides the electrons produced by the MCP towards the chip. Subsequently, the floating anodes—deposited using the metal layer on top of the CMOS chip—collect these electrons.
Mass spectra from DFMS Examples of low (top) and high resolution (middle and bottom) mass spectra from DFM.
Publications
- De Keyser, J.; Gibbons, A.; Dhooghe, F.; Altwegg, K.; Balsiger, H.; Berthelier, J.-J.; Fuselier, S.A.; Gombosi, T.I.; Neefs, E.; Rubin, M. (2019), “Calibration of parent and fragment ion detection rates in Rosettas ROSINA/DFMS mass spectrometer”, International Journal of Mass Spectrometry, Vol. 446, A116233, DOI: 10.1016/j.ijms.2019.116233
- De Keyser, J.; Altwegg, K.; Gibbons, A.; Dhooghe, F.; Balsiger, H.; Berthelier, J.-J.; Fuselier, S.A.; Gombosi, T.I.; Neefs, E.; Rubin, M. (2019), “Position-dependent microchannel plate gain correction in Rosetta's ROSINA/DFMS mass spectrometer”, International Journal of Mass Spectrometry, Vol. 446, A116232, DOI: 10.1016/j.ijms.2019.116232
- De Keyser, J.; Dhooghe, F.; Gibbons, A.; Altwegg, K.; Balsiger, H.; Berthelier, J.-J.; Briois, C.; Calmonte, U.; Cessateur, G.; Equeter, E.; Fiethe, B.; Fuselier, S.A.; Gombosi, T.I.; Gunell, H.; Hassig, M.; Le Roy, L.; Maggiolo, R.; Neefs, E.; Rubin, M.; Semon, T. (2015), “Correcting peak deformation in Rosetta's ROSINA/DFMS mass spectrometer”, International Journal of Mass Spectrometry, Vol. 393, 41-51, DOI: 10.1016/j.ijms.2015.10.010
- Balsiger, H.; Altwegg, K.; Bochsler, P.; Eberhardt, P.; Fischer, J.; Graf, S.; Jäckel, A.; Kopp, E.; Langer, U.; Mildner, M.; Müller, J.; Riesen, T.; Rubin, M.; Scherer, S.; Wurz, P.; Wüthrich, S.; Arijs, E.; Delanoye, S.; De Keyser, J.; Neefs, E.; Nevejans, D.; Rème, H.; Aoustin, C.; Mazelle, C.; Médale, J.-L.; Sauvaud, J.A.; Berthelier, J.-J.; Bertaux, J.-L.; Duvet, L.; Illiano, J.-M.; Fuselier, S.A.; Ghielmetti, A.G.; Magoncelli, T.; Shelley, E.G.; Korth, A.; Heerlein, K.; Lauche, H.; Livi, S.; Loose, A.; Mall, U.; Wilken, B.; Gliem, F.; Fiethe, B.; Gombosi, T.I.; Block, B.; Carignan, G.R.; Fisk, L.A.; Waite, J.H.; Young, D.T.; Wollnik, H. (2007), “Rosina - Rosetta orbiter spectrometer for ion and neutral analysis”, Space Science Reviews, Vol. 128, Issue 1-4, 745-801, DOI: 10.1007/s11214-006-8335-3
- Neefs, E.; Nevejans, D.; Schoon, N.; Arijs, E. (2004), “Le système de détection du spectromètre de masse à double focalisation de l'expérience ROSINA: la participation belge à la mission Rosetta", Ciel et Terre, Vol. 120, Issue 2, 42-44
- Neefs, E.; Nevejans, D.; Schoon, N.; Arijs, E.; Illiano, J.-M.; Berthelier, J.-J.; Altwegg, K.; Fischer, J. (2001), “The Detection System of the Double Focusing Mass Spectrometer (DFMS) for the ROSINA Experiment on the Rosetta Mission”, Space Scientific Research in Belgium, Vol. II Space Sciences, Issue Part 2 (1994-2000), 119-130
- Thomas, N.; Keller, H.U.; Arijs, E.; Barbieri, C.; Grande, M.; Lamy, P.; Rickman, H.; Rodrigo, R.; Wenzel, K.-P.; A'Hearn, M.F.; Angrilli, F.; Bailey, M.; Barucci, M.A.; Bertaux, J.-L.; Brieß, K.; Burns, J.A.; Cremonese, G.; Curdt, W.; Deceuninck, H.; Emery, R.; Festou, M.; Fulle, M.; Ip, W.-H.; Jorda, L.; Korth, A.; Koschny, D.; Kramm, J.-R.; Kührt, E.; Lara, L.M.; Llebaria, A.; Lopez-Moreno, J.J.; Marzari, F.; Moreau, D.; Muller, C.; Murray, C.; Naletto, G.; Nevejans, D.; Ragazzoni, R.; Sabau, L.; Sanz, A.; Sivan, J.-P.; Tondello, G. (1998), “Osiris - The optical, spectroscopic and infrared remote imaging system for the Rosetta orbiter”, Advances in Space Research, Vol. 21, Issue 11, 1505-1515, DOI: 10.1016/S0273-1177(97)00943-5
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