Hello!
I recently repaired a planar HPGe, a very old unit, but it works!
It's got a Be window, so it has a very nice response to low energy photons, down to circa 5 keV.
Anything lower than that will be absorbed in the Ges dead layer and Au contact layer.
It nicely shows the low energy peaks in the Am spectrum, but I have not too many nuclides with low energy emissions, so I want to try and build an XRF analyser with the components I have here.
Planar HPGe
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GigaBecquerel
- Posts: 172
- Joined: 04 Jul 2020, 07:34
Planar HPGe
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Sesselmann
- Posts: 1398
- Joined: 27 Apr 2015, 11:40
Re: Planar HPGe
....envy!
I wish there was a way to get these kinds of spectra without the cryogenic cooling. Would love to invent a low cost detector that could do this, but if the energy spread is purely due to molecular movement it obviously can't be done. Thinking about it..
Steven
I wish there was a way to get these kinds of spectra without the cryogenic cooling. Would love to invent a low cost detector that could do this, but if the energy spread is purely due to molecular movement it obviously can't be done. Thinking about it..
Steven
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GigaBecquerel
- Posts: 172
- Joined: 04 Jul 2020, 07:34
Re: Planar HPGe
Steven,
A pure silicon crystal has no molecules in it.
SiPIN diodes, or better SDDs reach a similar resolution, if not better, only peltier cooled.
But due to both their lower Z and volume they are way less efficient, barely usable at or above 50 keV.
Just raising the volume you'd get higher dark current, thus noise, so just making bigger crystals isn't viable either.
If you find a way to make HPGe-like spectra at room temp you did it in life.
A pure silicon crystal has no molecules in it.
SiPIN diodes, or better SDDs reach a similar resolution, if not better, only peltier cooled.
But due to both their lower Z and volume they are way less efficient, barely usable at or above 50 keV.
Just raising the volume you'd get higher dark current, thus noise, so just making bigger crystals isn't viable either.
If you find a way to make HPGe-like spectra at room temp you did it in life.
