The desired residence time within the cracking chamber, which is the time available for photolysis should be in {HEAD ~ the range} of {TAIL ~ a few milliseconds to several hundred milliseconds} 
The desired residence time within the cracking chamber , which is the time available for photolysis should be in { HEAD ~ the range } of { TAIL ~ a few milliseconds to several hundred milliseconds }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL