Since the departure of Keith Curle, Kiwomya has been in the hot-seat at Meadow Lane, while the League One outfit looked for a new permanent manager.
However, the 43-year-old has impressed during his brief spell in charge and Magpies chairman Ray Trew believes he has deserved his chance to manage the team for the rest of the campaign.
He told the club's website: "Chris has shown his desire and enthusiasm for the job and coupled this with a tactical astuteness that has allowed him to turn things around when they haven't been going exactly as we would have liked.
"We will, of course, review the situation at the end of the season. But Chris now has the chance to show us exactly what he can do, in the knowledge that he has an extended spell in charge."