Construction/

[mdede439]

I love this project! I am eager to build one of these but I have not seen and construction guides or pictures of a finished device. I am also interested how well this working? Should I try a Beta version of this device or wait for a later version?

[pingud98]

Thanks! I just created an issue to add some hardware photos, inc. one I had on my phone. I've made one change since this upload. The original 2.0 spin of the PCB uses a soft uart in the Raspberry Pi Zero 2 W. However, during testing this was a bit problematic, (out of order characters make GPS decoding impossible!) so for the next hardware spin I've added back the traces to the STM32. Apart from this everything checked out ok.

[mdede439]

Great!! Thanks for the update. I like the pic, however I was more interested in how the scintillator mounts to the SiPM. Is there additional hardware that holds the scintillator to the board? I also see that the SiPM is connected via coax connections. Is this choice to allow the SiPM/scintillator board to be mounted in a separate box?

I look forward to your future updates!

[pingud98]

I've double checked - the kicad files are indeed the latest version already with the GPS link to the STM32 reinstated. For the scintillator mounting, here's how it works: 1) When the board is produced, there are traces that wire up the SiPMs in situ, to allow testing before you snap the SiPM part off. (we didn't do this yet but..) 2) There are mouse bites that facilitate the snap-off of the SiPM + LED module, which has the micro-coax connectors. These replace the test traces for actual use. 3) When snapped off, the SiPM part of the PCB is designed to be screwed to the end of a 100 mm x 200mm x 10mm scintillator (BC-408 or equivalent). This is what the plated holes are for. We have drilled 2 holes in the scintillator matching these holes and we epoxy an M3 grub screw into each hole, with washers and nuts used to secure the PCB to the face of the scintillator. The two scintillators stack and the grub screws hold the SiPMs tight to the surface, with a slight flex on the PCB to maintain the pressure (of course it's important not to overtighten otherwise the PCB might crack!). The scintillator can be wrapped ahead of time with a slot for the SiPMs, or the whole thing can be wrapped as one module. We wrap in aluminium foil (shiny side in) and black electrical tape for the joints. 4) The u.FL connectors can be snapped in and the system will work; make sure not to get them mixed up! (We have tested this, nothing too bad happened.. but to be avoided). We have used u.FL terminated micro coax cables between 10cm and 15cms long. I would recommend keeping these leads short, and of course the same length on both channels. 5) We put the whole thing (scintillators underneath, some of the foam around and then the detector PCB sitting on top) in a small plastic pelican case (the cheap ones, not the $200+ genuine articles - which are excellent), with an IP54 USB and GPS (SMA coax) passthrough and close the lid for light tight and relatively waterproof operation.

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On Tue, 14 Jan 2025 at 21:10, mdede439 ***@***.***> wrote: Great!! Thanks for the update. I like the pic, however I was more interested in how the scintillator mounts to the SiPM. Is there additional hardware that holds the scintillator to the board? I also see that the SiPM is connected via coax connections. Is this choice to allow the SiPM/scintillator board to be mounted in a separate box? I look forward to your future updates! — Reply to this email directly, view it on GitHub <#1 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AANTLJ6PSPUEV6SNPJILNPT2KVVK3AVCNFSM6AAAAABU5TT7BCVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDKOJRGAYTAMZXGI> . You are receiving this because you commented.Message ID: ***@***.***>

[mdede439]

Thanks for the detailed description. I found this, https://www.youtube.com/watch?v=iMmBWL2BVwI, video detailing the assembly of v1.6 of the device. I assume this is, in part, what you are describing. Although you have the assembled device in a Pelican type case rather than a Hammond box.

My biggest issue now is finding the scintillators.