The sticking coefficient of nitrogen gas on a thick solid nitrogen film on a copper cold finger was studied at low temperature. For surface temperatures of about 12 K the sticking coefficient is measured to be 99.0 +/- 0.6%. Our result implies that it will be possible to make a intense and high brightness slow positron source starting from a small diameter deposit of the gaseous positron emitter N-13(2) produced in the reaction C-12(d,n)N-13. (C) 2007 Elsevier B.V. All rights reserved.