PC-12
Air Traffic Control Fully Certified
Air Traffic Control Radar 25
Distraction; Human-Machine Interface; Situational Awareness
ATC Issue All Types; Conflict Airborne Conflict
Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance
Human Factors
There was a refueling track active blocking FL200B220 at the time. A PC12 was handed off at FL220 and I requested control to descend them. They were from the north moving south landing. When they checked on I descended them to 150 for the refueling track and start a slow descent for destination. I then received a call from approach NON-Radar sector requesting an altitude for a LJ60 off of ZZZ1 to ZZZ2. I approved 140 for the LJ60. When the LJ60 checked on freq I called them radar; and then stopped the PC12 at 170 so I could keep the LJ60 climbing to 160. I had put a circle on the PC12 and was waiting for them and the LJ60 to separate at which time the refueling aircraft would be opposite direction of the LJ60 and I would be able to climb the LJ60 to my top alt of 230. While waiting I received a call from requesting the LJ60 to be at 140 for traffic he had. I told him I would and immediately descended the LJ60 to 140 seeing the traffic. At that time I had in my mind that everyone was separated so no conflictions. I then had a thought of an issue at home and wrote myself a note about it; stuck it in my pocket and started my scan. Seeing what I had done I turned the PC12 to the west just as he was going though 161 and then in the hope that the LJ60 would see the PC12 called traffic trying to get visual and then climb the LJ60. The LJ60 did have the PC12 in sight and asked if he should climb or descend. I climbed him to FL190 under the refueling track. I was so surprised that I had trouble getting the heading out for the PC12 and stammering on frequency. I'm sure that was what leads the LJ60 to ask the question that he did.It was my distracting thought that took my attention away. We only occasionally have refreshers about these types of things; it is normally about things in the area; which has always been a problem.
ARTCC Controller has a plan to separate aircraft; becomes distracted thinking about a personal situation; and loses separation between two aircraft.