LDEB vs LDE3L performance difference

[DavidAdams]

Hello,

The people who designed the spectrometer setup on my microprobe didn't add a diffractor that can detect Be. That's something the chemists around here are very interested in looking to quantify but I can only go down do B at the moment. For some reason they designed my microprobe setup to have LDE1 and LDE1L crystals even though the LDE1L crystal performance is worse than for the LDE1 crystal. 

Does anyone have an LDE3L diffractor on their instrument? I'm trying to determine the performance difference between the LDEB and LDE3L diffractors provided by JEOL. Specifically I'm looking for the P/B and the cps/absorbed current(na) of the LDE3L crystal.

I have performance data for the LDEB and LDE3H crystals but not for the LDE3L crystal.

Thanks!
Dave

[Anette von der Handt]

Hi Dave,

I don't have data for a LDE3L and don't know anyone who has this monochromator. However, if the relative sensitivity changes between LDE1 and LDE5 in their respective L vs H form apply to the LDE3 as well, I would expect to see peak counts of 420-440 cps/nA and a p/b of 62-74 for Be Ka at 10kV on the LDE3L. For comparison, spec for LDEB I see peak counts of 70 cps/na and p/b of 60.

Nevertheless, I would expect that JEOL should be able to give you these numbers for LDE3L, no? I am also a little bit surprised to hear that the LDE1L gives you worse performance than the LDE1, based on specs it should give you 1.7 - 2.8 times better counts (but worse p/b).

Cheers,
Anette

[DavidAdams]

Hi Dave,

I don't have data for a LDE3L and don't know anyone who has this monochromator. However, if the relative sensitivity changes between LDE1 and LDE5 in their respective L vs H form apply to the LDE3 as well, I would expect to see peak counts of 420-440 cps/nA and a p/b of 62-74 for Be Ka at 10kV on the LDE3L. For comparison, spec for LDEB I see peak counts of 70 cps/na and p/b of 60.

Nevertheless, I would expect that JEOL should be able to give you these numbers for LDE3L, no? I am also a little bit surprised to hear that the LDE1L gives you worse performance than the LDE1, based on specs it should give you 1.7 - 2.8 times better counts (but worse p/b).

Cheers,
Anette

Hi Anette,

Thank you for the reply!

I was working off of data provided by JEOL but their list of crystals is missing the performance data for that particular monochromator.

You're correct about the count rate for my LDE1L crystal. It does show the about a 1.8-2.9 better count rate but the p/b is significantly worse.

Cheers,
Dave