Building a better outdoor fireplace. Infra red transfer optimization.

I am experimenting with an outdoor fireplace. Currently I am using a stainless steel tub from a washing machine. What I am noticing is that while the vessel gets hot it overall radiates very little. (unless fire is intense and vessel is glowing red hot). If I have line of sight to the fire/coals the radiated heat is substantial but drops off dramatically once below the rim of the vessel. I also use a ceramic coated clothes dryer drum placed on top to suppress sparks/embers at times and to safely contain the fire when unattended. *see attached images

Goals-

g1- To maximize heat transfer from fire to area of people seated around the fire.

g2- To keep the fire safely contained to prevent sparks/embers from escaping and igniting dry brush etc.

Ideas thus far- 

i1- mount an inverted aluminum cone above the fire to reflect 45deg (aluminum is supposed to be a decent reflector of infra red radiation) *see attached drawing Fig. A

i2- cut square/rectangular openings in the vessel and insert tempered glass panels to allow infra red to radiate lower

i3- change stainless vessel to an aluminum vessel (beer keg etc.?)

Any comments and ideas appreciated. Fun to experiment and learn!