Staff cannon
From The Stargate Omnipedia
Stationary field weapon used by the Jaffa for large-scale combat operations. The staff cannon is a larger and more powerful version of the staff weapon and death glider cannon technology, delivering a powerful blast of charged plasma at its target.
The cannon is mounted on a large tripod base, which allows the weapon to be turned 360 degrees for target acquisition. It can be deployed into the field of combat relatively quickly, and is operated by a single Jaffa using two handles.
KEY EPISODE
There But For the Grace of God - In a parallel reality, Teal'c uses a staff cannon erected inside the S.G.c. during an invasion to shoot Jack O'Neill dead.