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

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 accelerating") OR ("particle acceleraton")))).
• Removing quotes may allow a broader search: (( particle acceleration ) or ((( particle accelerating ) or ( particle acceleraton )))).
• Adding a wildcard symbol may retrieve word variants: (("particle acceleration") or ((("particle accelerating") or ("particle acceleraton"))))*.