You can try...
But lemme just tell you, it either won't work, or would take literally hours (the barrier is a bit special, Keiko did put it up to keep you guys out after all, so it has pretty high resistances to damage, you'll have to deal alot of damage at once repeatedly instead of just alot over time).
Keep firing it and it would break after well... well after the boss fight is over.
Or when Keiko dies.
But right now, I recommend trying something else. Probably a good time to bust out something new.