Effect of transmission losses on measured parameters in multi-ion coincidence momentum spectrometers

• We analyze the effect of transmission loss on the observed properties of molecular fragmentation.
• We calculate the loss factor for particles emitted in isotropic and anisotropic distributions.
• Loss factor for two-body breakup having isotropic distribution is derived.
• Problems in obtaining any general formula for loss factor for three-body and anisotropic distributions are discussed.
• A case of two-body fragmentation (N2++→N+,N+) is considered to highlight the importance of the loss analysis.

We address the effect of transmission losses on the measured kinematic parameters of molecular fragmentation processes in a time-of-flight based ion momentum spectrometer. We suggest means to correct for these losses for two-body fragmentation having isotropic distribution. As an example, we discuss the kinetic energy release spectrum observed in recoil ion momentum spectrometer of doubly ionized nitrogen molecules formed upon high energy electron impact. Further, we highlight the difficulties in calculating losses in many-body fragmentation and anisotropic emissions and show that such effects cannot be accounted without employing additional information about the process. In many cases, such information cannot be extracted from the observed data in the experiment and thus we have to rely on careful assumptions.

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