Minor Interruptions, Major Destruction

My supervisor has a terrible habit of interrupting constantly with inane questions.  Here is a summary of a conversation we had Monday many times this week.  (My thoughts are in parentheses.)

supervisor from hell:  WHERE IS THE SAMPLE ADMISSIONS LETTER YOU CAME UP WITH?

me:  IN THE FILE SHARE IN THE ADMISSIONS FOLDER (why does she even need to know this?!  she has done nothing regarding admissions)

supervisor from hell:  I CAN’T FIND IT.

me:  IT’S IN THE ADMISSIONS FOLDER, RIGHT–HERE–JUST, HOLD ON, I’LL JUST EMAIL IT TO YOU. (why do you even need this!?  why are you bugging me?)

supervisor from hell:  WHAT ARE YOU DOING?  (standing in my door way)

me:  (not looking at her, working at my computer)  I’M TRYING TO SEND THE ADMIT LETTERS BEFORE THE END OF THE DAY.  I’M FORMATTING THE LETTERS AND THEN CONVERTING THEM TO PDF–

supervisor from hell:  –YOU SHOULD REALLY CONVERT THEM TO PDF.  THAT’S WHAT THEY DO IN THE OTHER DEPARTMENTS–

me:  –I KNOW.  I AM.  I SENT THAT FILE YOU ASKED FOR.  IT SHOULD BE IN YOUR EMAIL INBOX NOW.  (get out of my office.  why are you bugging me!!?)

supervisor from hell:  OH YOU ARE SO SMART.  SEE, I DON’T EVEN HAVE TO TELL YOU.  I DON’T KNOW WHY I COULDN’T FIND THAT FILE BEFORE.  THANKS.  HOW WEIRD.  DO YOU NEED HELP?

me:  (it’s 4:47.  i have worked all day and all of Monday trying to accomplish this stuff.  not once have you asked if i needed help.  this is just like that time you asked me if i needed help on a friday at 6:45 pm and i’d been staying late every day that week.)  I’M FINE.  I’M ALMOST DONE.

supervisor from hell:  YOU’RE AMAZING.  I TOLD THE WHOLE STAFF.  IT’S LIKE YOU’RE A PRO.  (yes, you sent out a thank you email to me and then decided to send it to everyone so you resent it to show everyone what an amazing supervisor you are and how kind you are to bestow your gratitude.)

me:  (looking at the clock.)  I’M DONE.  I WANT TO GO HOME NOW.

supervisor from hell:  YOU SHOULD GO HOME.  YOU’VE BEEN WORKING SO HARD.  LET’S WALK TO THE PARKING LOT TOGETHER.

me:  (great…)

I don’t know what other tactics I can employ to get my supervisor to leave me alone so I can do my work.  Even if I close my office door she’ll just knock on it and let herself in.  It’s so aggravating.  Suggestions?