TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: The reaction system is multiple reaction zone tubular reactors and/or autoclave reactors.    TECHNOLOGY FOCUS - POLYMERS - Preferred Components: The polyethylene resin comprises 5-95 wt.% of polymer units derived from the polar comonomer and 5-95 wt.% of polymer units derived from ethylene. The 3-12C unsaturated modifiers is present at 0.4-4 wt.%, based on the total first amounts of ethylene, polar comonomer, 3-12C unsaturated modifiers and initiator in the reaction system. The polyethylene resin has a melt index of 0.40-0.45x 102 decigram/minute and a polar comonomer content of 30-35 wt.%, and a crosslink index (MH-ML) of at least 2 (preferably greater than 2.4) dNasteriskm. The polar comonomer is vinyl acetate. The copolymer has a melt index of 40-45 decigram/minute and a vinyl acetate content of 30-35 wt.%. The copolymer has a melt index, as measured according to ASTM D1238 (2.16 kg, 190 degrees C), of 0.40x 102-0.50x 102 g/10 minute. The polar comonomer comprises vinyl acetate, where the copolymer comprises 30-45 wt.% of polymer units derived from vinyl acetate monomer and at least 50 wt.% of polymer units derived from ethylene. Preferred Process: The reaction conditions comprise an average reactor temperature of 190 degrees C or less, and a reactor pressure of at least 18x 102 bar. The step of removing a portion of the purge gas recycle comprises removing at least 30 vol.% of the purge gas recycle, or at least 30 wt.%, preferably 100 wt.% of the purge gas recycle, and removing at least a portion of remaining portion of the polar comonomer from the reaction system includes removing at least 30 vol.%, or at least 30 wt.%, preferably 100 wt.% of the remaining portion of the polar comonomer from the reaction system. The process for producing high pressure polyethylene having increased crosslinkability, comprises: contacting first portions of ethylene, the polar comonomer and the unsaturated modifiers in the presence of a first portion of an initiator in a reaction system at sufficient reaction conditions to produce the effluent comprising polyethylene resin, an unreacted portion of polar comonomer and purge gas; controlling the reaction conditions to maintain a ratio of the concentration of the unsaturated modifiers to the concentration of the polar comonomer to provide the polyethylene having the target crosslink index (MH-ML); and isolating the polyethylene resin having the target crosslink index (MH-ML), where the target crosslink index (MH-ML) is at least 5% higher than the crosslink index (MH-ML) of a comparable high pressure polyethylene prepared under substantially the same conditions except that the controlling step is not performed. In the process: controlling the reaction conditions includes removing a portion of the purge gas recycle stream before returning the remaining portion of the purge gas recycle stream to the reaction system; controlling the reaction conditions includes removing at least a portion of unreacted portion of the polar comonomer from the comonomer recycle stream before returning the comonomer recycle stream to the reaction system; controlling the reaction conditions includes maintaining an average reactor temperature of 190 degrees C or less, preferably 140 degrees C; and controlling the reaction conditions includes maintaining a reactor pressure of at least 18x 102 bar. EXAMPLE - No suitable example given.