model a halogen lamp which will heat up a metal plate

Hello,

I would like to model a halogen lamp which will heat up a metal plate.
I constructed a solid cube and define 2000W on a face of the cube. the other 5 faces are insulated. I used 'diffuse surface' to model the radiation coming out from halogen lamp and metal plate (radiosity). The heat is dissipated from metal by convection. I used 'heat transfer in solid' to simulate the model. The halogen lamp is 300 mm away from metal plate (aluminium).

However, after heating for 200s, the temperature increment in metal is almost negligible (0.02 degree C).

I suppose the problem might be due to the improper modelling of halogen lamp.

It would be much appreciated if anybody could assist for same.

Thanks and Regards,
Arnab