Light Element Crystal Refractive Index Values

[John Donovan]

Two questions on JEOL LDE crystals:

1. What is the 2d spacing for the JEOL LDEC? I see 100A but also 200A elsewhere. Which is correct?  😕

2. What is the refractive index (k) for LDEB?  The default K value (0.01) I have for LDEB is clearly too low! 

[irisbuisman]

John, Julien, -
Thank you for all your help and advice.  I have used the values Julien found/calculated for the LDE1 (2d = 61.4A and k= 0.013) and have now got an offset of just -0.0624 mm.  An incredible improvement over the close to 2mm offset I had before.

(my first forum post! and I finally figured out how!)

[John Donovan]

John, Julien, -
Thank you for all your help and advice.  I have used the values Julien found/calculated for the LDE1 (2d = 61.4A and k= 0.013) and have now got an offset of just -0.0624 mm.  An incredible improvement over the close to 2mm offset I had before.

(my first forum post! and I finally figured out how!)

Very nice!

[John Donovan]

I'd still like to get an answer to my questions here from anyone:

https://smf.probesoftware.com/index.php?topic=375.msg12962#msg12962

[Anette von der Handt]

Two questions on JEOL LDE crystals:

1. What is the 2d spacing for the JEOL LDEC? I see 100A but also 200A elsewhere. Which is correct?  😕

It is 100A and uses V/C. I don't know where the 200A comes from, probably a type. With a 'd' of 200A you would not reach C Ka on a JEOL spectrometer.

2. What is the refractive index (k) for LDEB?  The default K value (0.01) I have for LDEB is clearly too low!

Julien got the following for his Boulder probe (see first page of this thread).
- LDEB (150 Å): 2d = 149.4 Å / k = 0.035

[John Donovan]

Two questions on JEOL LDE crystals:

1. What is the 2d spacing for the JEOL LDEC? I see 100A but also 200A elsewhere. Which is correct?  😕

It is 100A and uses V/C. I don't know where the 200A comes from, probably a typo. With a 'd' of 200A you would not reach C Ka on a JEOL spectrometer.

2. What is the refractive index (k) for LDEB?  The default K value (0.01) I have for LDEB is clearly too low!

Julien got the following for his Boulder probe (see first page of this thread).
- LDEB (150 Å): 2d = 149.4 Å / k = 0.035

This is very helpful, thank-you!

Here is what we have as defaults for the LDE type Bragg crystals in our CRYSTALS.DAT file:

 "WSi45"     45.0           0.010       "o"     "ka"
 "LDE45"     45.0           0.010       "o"     "ka"
 "PC0"       45.0           0.006       "o"     "ka"
 "WSi55"     55.0           0.014       "o"     "ka"
 "LDE1L"     60.2           0.014       "o"     "ka"
 "WSi60"     61.0           0.01483     "o"     "ka"
 "LDE1"      61.1           0.01        "o"     "ka"
 "LDE1H"     62.5           0.008       "c"     "ka"
 "WSi63"     63.0           0.015       "o"     "ka"
 "LDE1L"     60.2           0.014       "o"     "ka"
 "PC1"       60.6           0.00832     "o"     "ka"
 "NiCrBN"    65.0           0.016       "o"     "ka"
 "LDE5L"     80.1           0.018       "c"     "ka"
 "NiC"       80.2           0.018       "c"     "ka"
 "LSM"       80.0           0.03        "c"     "ka"
 "PC2"       95.0           0.021       "c"     "ka"
 "OV95"      96.8           0.02        "c"     "ka"
 "STE"       98.0           0.          "c"     "ka"
 "LDE2"      98.0           0.01        "c"     "ka"
 "LDE2H"     98.0           0.01        "c"     "ka"
 "LDEC"      100.           0.04        "c"     "ka"
 "PbSd"      100.6          0.          "c"     "ka"
 "PbSTEA"    100.6          0.          "c"     "ka"
 "ODPB"      100.7          0.0175      "c"     "ka"
 "LDE6H"     120.0          0.02        "c"     "ka"
 "WC144"     144.0          0.03        "b"     "ka"
 "LDEB"      145.0          0.035       "b"     "ka"
 "PC25"      147.66         0.02        "b"     "ka"
 "OV160"     160.0          0.03        "b"     "ka"
 "MoB4C"     194.57         0.04        "b"     "ka"
 "OV200"     197.4          0.04        "b"     "ka"
 "LDE3H"     200.0          0.02        "be"    "ka"
 "PC3"       200.5          0.02        "be"    "ka"

Any other suggestions?