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Saunders, M.

Publications and source records attributed to Saunders, M..

Workshop on Discovery Lessons-Learned

As part of the Discovery Program's continuous improvement effort, a Discovery Program Lessons-Learned workshop was designed to review how well the Discovery Program is moving toward its goal of providing low-cost research opportunities to the planetary science community while ensuring continued U.S. leadership in solar system exploration. The principal focus of the workshop was on the recently completed Announcement of Opportunity (AO) cycle, but the program direction and program management were also open to comment. The objective of the workshop was to identify both the strengths and weaknesses of the process up to this point, with the goal of improving the process for the next AO cycle. The process for initializing the workshop was to solicit comments from the communities involved in the program and to use the feedback as the basis for establishing the workshop agenda. The following four sessions were developed after reviewing and synthesizing both the formal feedback received and informal feedback obtained during discussions with various participants: (1) Science and Return on Investment; (2) Technology vs. Risk; Mission Success and Other Factors; (3) Cost; and (4) AO.AO Process Changes and Program Management.

Saunders, M.

Thermionic converter output as a function of collector temperature

Surprisingly few data are available on the variation of thermionic converter output with collector temperature. In this study the output power density has been measured as a function of collector temperature (at a fixed emitter temperature of 1650 K) for six converters with different electrode combinations. Collector temperatures ranged from 750 to 1100 K. For collector temperatures below 900 K, converters built with sublimed molybdenum oxide collectors gave the best performance.

Stark, G.

Crossed beam studies of ion-molecule reactions in methane and ammonia

A crossed-beam apparatus is used to measure the product ion velocity and angular distributions for the following ion-molecule reactions in the relative energy range from 2 to 9 eV: CH4(+) + NH3 yields NH4(+) + CH3; CH4(+) + NH3 yields CNH5(+) + H2; NH2(+) + CH4 yields CNH4(+) + H2 (or 2H); and CH3(+) + NH3 yields CNH4(+) + H2 (or 2H). These reactions are also studied by means of deuterium labeling as a further probe of the detailed reaction dynamics. Probability contour plots for the four reactions are constructed in Cartesian velocity space, and product peaks in the plots are discussed. Relative cross sections and Q values are computed for two of the reactions as well as for the corresponding deuterium-labelled reactions. The results show that the present ion-neutral condensation reactions are highly exothermic with a deep well for the internal complex, that little hydrogen scrambling occurs, and that the energy of the reactions is released mainly as internal energy, even to the extent of producing two hydrogen atoms in some cases rather than one hydrogen atom or molecule.

Smith, G. P. K.