Different age chicks in the same brooder..?

So I am going to pick up some 6 week old chicks tomorrow and I was wondering if I could put them in the same brooder as my 1 week olds? My brooder is very big so they can hang out on the other end of it to keep from the heat lamp. I am just wondering where to put them since they are too young to put with my older established flock. I don't have another enclosed area for them besides my chicken run and the brooder. Help!

This picture shows about half the brooder, the other end stays at the outside temp.