Wow. In order to answer this, you need to go look up a couple definitions.
Relax. Keep your seat. Don't trouble yourself. I'll go look them up for you.
It's a small price to pay to earn the whopping 5 points that awaits me at the
end of the rainbow.
1 Coulomb = 6.2415 x 10¹⁸ elementary charges
1 electron volt = 1.60217657 × 10⁻¹⁹ joules
Each proton carries one elementary charge, just like an electron does.
8.6 mA = 0.0086 Ampere =
0.0086 coulomb per second = 5.3677 x 10¹⁶ charges per second
Energy delivered to the target =
(number of protons) x (energy of each proton) =
(5.3677 x 10¹⁶)x(20 MeV) x (1,000 eV / MeV)x(1.60217657 × 10⁻¹⁹ joules / eV) =
172 joules per second
(172 watts)