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Incorrect LYSO Density #99

Closed dfreese closed 7 years ago

dfreese commented 7 years ago

Not sure if this has been brought up before, but the density for LYSO in the materials database has a listed density of 5.37 g/cm3, but it should be 7.4g/cm3, like LSO.

dfreese commented 7 years ago

Sorry, close to LSO, at 7.11g/cm3 as per L. Pidol et al., "High efficiency of lutetium silicate scintillators, Ce-doped LPS, and LYSO crystals," in IEEE Transactions on Nuclear Science, vol. 51, no. 3, pp. 1084-1087, June 2004.

mchamberland commented 7 years ago

Yes, this has been discussed on the mailing list before. The problem is that there is no "one" correct density for LYSO. Please see Michaela's post. I'm not sure how the Gate developers should handle this...

patayg commented 7 years ago

Indeed, LYSO density varies from vendor to vendor. However, not all users are aware of such subtleties, so a "not so bad" value should be provided (e.g. 7.3 g/cm3 or something similar is still better than the current 5.37).

mchamberland commented 7 years ago

Yes, I agree. Hopefully, someone on the Gate team also agrees!

dfreese commented 7 years ago

@mchamberland and @patayg thanks for clarifying that. Hopefully it can be changed to something generically useful. People who know their exact crystal specs are going to change it anyway.

dsarrut commented 7 years ago

Hello, what do you suggest ? Could you provide a "not so bad" replacement for the current values ? thanks

dfreese commented 7 years ago

I would suggest anything between the reference I posted previously at 7.11g/cm3, and the 7.3g/cm3 @mchamberland mentioned from the mailing list post. (The previous google cache link was dead)

I haven't seen any values in literature quoted outside of this range, though I'm always happy to be proven wrong. My preference would be to chose a value with a valid reference in literature, so I would suggest 7.11g/cm3, but I there are perhaps other references that could be cited.

dsarrut commented 7 years ago

Done : commit 70c112c676ba4be345a8a5945d5a64d2ce7cfba2

dfreese commented 6 years ago

I noticed commit 18d42d1 reverted this change. Was that intentional? It doesn't seem related to the PR.

dsarrut commented 6 years ago

Revert the reversion ... (don't know why it was reverted) e4ef6b551b204e7f25ba62e1f50718707ec4d1b0 fda5f9f347723d98ea7e236068e59204e9f7bf39

MarieleStockhoff commented 6 years ago

The LYSO in the main database is updated but the incorrect definitions are still hiding in the .db in the examples.

dfreese commented 6 years ago

I'm not super familiar with the GATE development process, but it looks like those files are there from whenever the benchmarks were run after a breaking change.

Have you noticed a situation where these have caused confusion? If so, perhaps a readme could be added to those data folders cautioning against that, or something similar.