In XRD, the decreasing in peak refers to the produced crystal is small may be formed nanomaterials if the crystal size of it at ranged 1-100 nm.

Thanks Thomas Breuer, we will do a thorough alignment check.

Definitely we will put a standard and do the intensity check.

I was only wondering do Goebel mirrors go bad by any chance ?

K. Sreenivas

New detector: What is about the HV working point of your scintillation detector?

You may play around with that voltage a bit to get the right working point.

All power supplies/volatages for detector ok?

Any protective shield (for transportation) left at the detector window?

New tube: is there any filter being left at the tube window or even a protective shield for transportation?

You may check the x-ray output by a dose meter. Dose rates should be mentioned in the tube's data sheet.

Is the kVp setting ok? Too low tube voltage will give low k-alpha yield.

Do the filters in your set up match with anode material of tube?

Adjustment was already mentioned by Thomas.

Goebel mirror: It seems to me very unlikely that just at moment when tube and detector are changed the mirror goes bad.

Luma is right with her answer; but I think you have used standard samples having right crystallite size when making your tests.

But be careful when exposing the detector to the full primary beam. Please use some filtration and work with lowest mA and kVp (only for XRD peaks it is necessary to go for kVp well above k-edge excitation threshold of tube material).

According to

https://www.bruker.com/products/x-ray-diffraction-and-elemental-analysis/x-ray-diffraction/d8-advance/technical-details.html

there is a "SNAP LOCK switch to dedicated optics or different wavelengths".

Is that SNAP LOCK appropriately set after changing of tube and detector ? ( i.e. really snapped and really locked ? for all components in your set up)

We are really thankful to both Dr. Gerhard, and Thomas Breuer for

very valuable suggestions. Definitely I am taking care of all the pitfalls, and cross check mechanisms and hopefully we will try to get the diffractometer into good working condition. I will once again thank you al and keep you updated, on what happens.

Prof. K. Sreenivas

I do thank all the people who provided valuable suggestions.

In the Engineer from Bruker was also kind enough to come over, and help us to examine the problem we were placing.

1) The engineer came and along, and with him we learnt how to solve the problem of low intensity.

2) Firstly the X-ray source module and its alignment were checked, to verify if the x-ray beam coming out of the goebel mirror is falling uniformly over the area where the sample is usually mounted.

3) The soller slit was also adjusted.

4) Finally we had a Nickel filter to cut down behind the soller slit,. We removed this, and the detected intensity almost doubled.

The consideration for removing the Nickel filter was due to the fact that

Goebel mirror itself is already minimising the Kb (K-beta) contribution, besides providing a parallel beam to be incident onto the sample.

Thanks for providing an update of your intensity issue.

there can be two problem- alignment issue or the source itself is faulty.

If straight intensity is high enough then it is an alignment issue.

otherwise please check out the source if it is over used and now full of defects. 2nd the monochromator (generally a quartz or any other kind of crystal) of the beam is properly aligned.

Prof. Sreenivas

I just want to know that with your previous set of x-ray tube and detector were you not using the Ni filter and Goebel mirror together.

Although the parallel beam geometry gives a good accuracy in the measurement. If a little compromise in accuracy is ok, I will suggest to open up the receiving slits to maximum possible. I actually tried it with a Rigaku system and it works very well.