MD11 CREW RECEIVES TCAS TA DURING VISUAL CLB IN SCT AIRSPACE.

Narrative

WE DEPARTED ONT AND WERE CLRED DIRECT TO PDZ VOR; THEN OUTBOUND ON THE PDZ 130 DEG RADIAL TO INTERCEPT THE OCN 080 DEG RADIAL. JUST AFTER PDZ; WHILE LEVEL AT 7000 FT; SOCAL DEP POINTED OUT TFC AT OUR 11 O'CLOCK POS; WBOUND; OUT OF 8500 FT FOR 8000 FT. WE RPTED TFC IN SIGHT. ATC THEN INSTRUCTED US TO MAINTAIN VISUAL SEPARATION; CLB AND MAINTAIN 12000 FT. I STARTED A SLOW CLB AS TO GIVE THE TFC TIME TO PASS OFF OUR R SIDE. AS WE BEGAN TO CLB WE GOT THE TCAS TA OF 'TFC; TFC' FOLLOWED BY 'MONITOR VERT SPD.' I DISCONNECTED THE AUTOPLT AND SLOWED OUR CLB RATE TO ABOUT ZERO. THE TFC WAS PASSING OFF TO OUR R AND THE TCAS FOLLOWED WITH 'CLR OF CONFLICT.' WE RESUMED TO CLB AND COMPLETED THE FLT NORMALLY. I DO NOT FEEL IT WAS A PROPER ATC CLRNC TO MAINTAIN VISUAL SEPARATION WHILE CLBING ACROSS ANOTHER ACFT'S PATH; ESPECIALLY AT NIGHT. IT WAS TOO DIFFICULT TO TELL WHETHER WE SHOULD EXECUTE A SLOW CLB AS I DID TO TRY AND LET THE TFC PASS OFF TO OUR R OR CLB AT A FASTER RATE TO GET THROUGH HIS ALT BEFORE OUR PATHS CROSSED. SINCE THE CTLR'S INSTRUCTION TO CLB; I FELT I NEEDED TO START UP AT LEAST AT A NOMINAL RATE. EVEN IF THIS WAS A PROPER ATC CLRNC; I WILL NEVER AGAIN ACCEPT AN ATC CLRNC TO MAINTAIN VISUAL SEPARATION AND CLB OR DSND THROUGH ANOTHER ACFT'S ALT WHILE ON A CONVERGING COURSE. IT IS SIMPLY TOO DIFFICULT AT NIGHT TO DETERMINE DISTANCE AND SEPARATION. MY JOB IS THE SAFETY OF THE ACFT AND CREW REGARDLESS OF ATC CLRNCS THAT ARE DIFFICULT OR DANGEROUS TO COMPLY WITH.