Perhaps you should try some spelling variations:
"particle acceleration" » "particle accelerators"
"particle acceleraton" » "particles acceleration", "particle accelerations", "pareticle acceleration"
"particle accelerator" » "particle accelerators"

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (("particle acceleration") OR ((("particle acceleraton") OR ("particle accelerator")))).
• Removing quotes may allow a broader search: (( particle acceleration ) or ((( particle acceleraton ) or ( particle accelerator )))).
• Adding a wildcard symbol may retrieve word variants: (("particle acceleration") or ((("particle acceleraton") or ("particle accelerator"))))*.