B737 Undifferentiated or Other Model
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 7
Distraction; Situational Awareness
ATC Issue All Types; Conflict Airborne Conflict; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance
General None Reported / Taken
Human Factors
I was working the R-side when this occurred. I had no D-Side. I climbed Aircraft Y to FL340; and he was climbing at 4000 feet per minute. As he was out of FL300 I assigned FL320 to Aircraft X; who was only out of FL240 and climbing at around 500 feet per minute. When Aircraft Y hit FL320 he reduced his rate of climb from around 4000 to 400. Aircraft X; conversely who was only doing around 500 increased it to 2000-3000 FPM. It was flashing when it was out of FL260 for 320 but I didn't really believe my conflict alert; because we get a ton of bad advisories and I had just checked the VRI (Velocity Reference Indicator). It flashed for around 2 minutes; and I went on for something else. When I went back to it; Aircraft X had climbed through FL315 and Aircraft Y was through FL325. I was thinking Aircraft Y was still climbing well; but he significantly shallowed his descent and I missed it.Military airspace was hot to the east of both airlines; which had put them on the same route (different fixes but overlapping). This provided for further complications in routes that are normally separate. Prior to plugging back into the position; my wife had called and texted me that she was crying about the shutdown; she was concerned with how long it was going to continue. I had tried to force this from my mind as I worked airplanes; but I believe it played a small part into what happened.I should use positive separation and less interpolation of altitudes and assign what I have available; instead. It's completely my fault.
Miami Center Controller reported a loss of separation due to different climb rates of two aircraft and failing to notice due to distractions.