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The acceleration of charged particles by interplanetary shocks (IPs) candrain a non-negligible fraction of the plasma pressure. In this study, we haveselected 17 IPs observed in-situ at $1\,\text{au}$ by the Advanced CompositionExplorer (ACE) and the Wind spacecraft, and 1 shock at $0.8\,\text{au}$observed by Parker Solar Probe (PSP). We have calculated the time-dependentpartial pressure of supra-thermal and energetic particles (smaller and greaterthan $50\,\text{keV}$ for protons and $30\,\text{keV}$ for electrons,respectively) in both the upstream and downstream regions. The particle fluxeswere averaged for 1 hour before and 1 hour after the shock time to remove shorttime scale effects. Using the MHD Rankine-Hugoniot jump conditions, we findthat the fraction of the total upstream energy flux transferred tosupra-thermal and energetic downstream particles is typically $\lesssim\!16\%$,in agreement with previous observations and simulations. Notably, by accountingfor errors on all measured shock parameters, we have found that for any givenfast magnetosonic Mach number, $M_{f}\!<7$, the angle between the shock normaland average upstream magnetic field, $\theta_{Bn}$, is not correlated with theenergetic particle pressure; in particular, the partial pressure of energizedparticles does not decrease for $\theta_{Bn} \gtrsim 45^\circ$. The downstreamelectron-to-proton energy ratio in the range $\gtrsim\!140\,\text{eV}$ forelectrons and $\gtrsim\!70\,\text{keV}$ for protons exceeds the expected$\sim\!1\%$ and nears equipartition ($>\!0.1$) for the Wind events.

In-situ Measurement of the Energy Fraction in Supra-thermal and Energetic Particles at ACE, Wind, and PSP Interplanetary Shocks