Ethylene polymers

A process comprising polymerizing ethylene with at least one olefin to produce a polymer,

• wherein said polymerizing is conducted in a polymerization zone,
• where said polymerization zone is essentially free of cocatalyst, and
• wherein said polymerizing is conducted using a catalyst,
• where said catalyst comprises chromium oxide on a support, and
• where the amount of said chromium on said support is from about 0.01 to 5 weight percent, and
• where said support comprises silica, and
• where said support is essentially free of titania, alumina and, phosphates, and
• where said support has a surface area from about 200 to about 550 square meters per gram, and
• where said support has a pore volume from about 0.7 to about 2.5 cubic centimeters per gram, and
• where said catalyst has been activated at a temperature in the range of about 600° C. to about 900° C. by using a oxidizing ambient, and
• where said catalyst after being activated is then reduced at a temperature in the range of about 200° C. to about 550° C. by using a reducing ambient, and
• wherein said polymerizing is conducted in the presence of hydrogen, and
• wherein the majority of said olefin is produced by said catalyst, during said polymerizing.