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

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 accelerator") OR ((((("particle accelerate") OR ("particle accelerators"))) OR ("particle accelerationd")))).
• Removing quotes may allow a broader search: (( particle accelerator ) or ((((( particle accelerate ) or ( particle accelerators ))) or ( particle accelerationd )))).
• Adding a wildcard symbol may retrieve word variants: (("particle accelerator") or ((((("particle accelerate") or ("particle accelerators"))) or ("particle accelerationd"))))*.