Perhaps you should try some spelling variations:
"particle acceleration" » "particle accelerators"
"particle accelerated" » "particles accelerated", "particle accelerator", "particle accelerators"
"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 accelerated") OR ("particle acceleraton")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"particle acceleration\") or (((\"particle accelerated\") OR (\"particle acceleraton\"))))".
• Removing quotes may allow a broader search: (( particle acceleration ) or ((( particle accelerated ) OR ( particle acceleraton )))).
• Adding a wildcard symbol may retrieve word variants: (("particle acceleration") or ((("particle accelerated") OR ("particle acceleraton"))))*.