Probably not much on the metal surface helping heat, because there there are rubber feet on the bottor to allow airflow on the bottom surface.
You can however place a goodly chunk of aluminum on the top of the main box, like I do on the one inside the graded shield, about 1" thick Al scrap piece. Copper even better. All for heat transfer, not rad shielding
From: "taray singh via groups.io" <sukhjez@...> To: [email protected] Sent: Monday, September 28, 2020 10:40:30 AM Subject: Re: [XRF] Si pin xrf ..1st go
Geo Ok will do it ... As you can see in the pic,I placed the detector on a ?metal surface I hope it also acts as a heatsink? Taray