Name: Myleen
Date: Wednesday 2006-04-05 17:56:11
Email: mmiralles@pi.ac.ae
Message (question/answer):
i have worked with SEM years ago and will be working on one again this time. however, we shall be acquiring an E-SEM this time which i am not familiar with. Quanta 200. anybody who can share an equipment buy-off checklist? also, anybody who uses the same system? can i bother you with lots of questions? =)
Name: Frank Eggert
Date: Thursday 2006-02-16 17:15:03
Email: eggert@mikroanalytik.de
Message (question/answer):
You should check the output signal of the detector. If there is a ramping and if there are little steps (if electron beam is on), you should be lucky. The detector works then. The other reason could be switches and thresholds in pulse processor or the processor is broken. Anyway, you should contact the service people or you want to risk much higher costs and further damages.
Name: HUSNAIN AHMED
Date: Thursday 2006-02-16 07:28:35
Email: husnain_ahmed_76@yahoo.com
Message (question/answer):
I have Oxford EDX attached with Jeol SEM. I have a problem that i am getting 100% dead time and not being able to acquire any Spectra. On running self diagnostic test, I got very high energy counts. I have run Heating-Cooling-Filling Liquid Nitrogen-Conditioning Cycle but the problem not solved. Is there anybody who can help me out.
With regards
Husnain Ahmed
Name: Frank Eggert
Date: Thursday 2006-01-26 07:02:13
Email: eggert@mikroanalytik.de
Message (question/answer):
Yes, it's true. With kV is meant the high voltage. If an electron was accelerated in this electrical field with e.g. 20 kV, the electron has finally an energy of 20 keV (1 keV is the energy of an electron (or other particle with one elemental charge) accelerated in an electrical field of 1 kV, this is the definition). [E.g. protons would not have the same value in energy and electrical field, like the electrons have (because they have an other mass).] This was wrong (the blue written text)! The correction is in 'italic letters' and 'light green'. Protons have the same value in energy, but because of other mass not the same speed... I've made the answer too quick, sorry...
Therefore you select the high voltage in a electron microscope (SEM or TEM) and the electrons will get the same value of energy (measured in keV units) before hitting the specimen.
Name: Marei Hacke
Date: Wednesday 2006-01-25 18:14:15
Email: a.hacke@postgrad.manchester.ac.uk
Message (question/answer):
Are the units kV and keV interchangeable for stating the accelerating voltage?
Name: Frank Eggert
Date: Thursday 2006-01-19 06:49:10
Email: eggert@mikroanalytik.de
Message (question/answer):
You can see all things, always a question of specimen preparation and possibilities of the SEM. The main problem possibly is the specimen charging. Variable pressure electron microscopes or the minimization of electron beam current can solve the difficulties.
If you want to measure the thickness at different points: With an EDX and e.g. Si-X-rays (base of the coating) you have for Carbon and Oxygen coating (1 um) a reduction of counts to about 86..88%. Therefore a quite simple thickness determination should be feasible.
Name: Shailesh
Date: Saturday 2006-01-14 09:51:37
Email: shailesh_zeo@rediffmail.com
Message (question/answer):
Is it possible to view transparnet thin polymer coating of thickness 1 micron in scanning electron microscope
Name: Frank Eggert
Date: Thursday 2006-01-12 19:15:21
Email: eggert@mikroanalytik.de
Message (question/answer):
I would be interested in getting feedback from people, who have already tested the ColorSEM software. Which opinions are there?
Name: Frank Eggert
Date: Tuesday 2006-01-03 19:42:11
Email: eggert@mikroanalytik.de
Message (question/answer):
Happy and successful new year 2006 to all X-ray spectrometry microanalysts and other visitors.
Name: Frank Eggert
Date: Wednesday 2005-09-07 14:08:42
Email: eggert@mikroanalytik.de
Message (question/answer):
Least Squares Method with EDX is a spectra-fitting method, which minimize the deviation between spectrum and model peaks (parameter optimization). The results are the peak areas (measured count rate) of overlayed peaks (deconvolution). The final \'Chi Square\' is a (weighted?) sum of all squares of deviations. Lower values indicate better fits, but not in all cases. The acceptable value depends from a lot of factors: the number of spectra-channels which are included, acquisition time, elements which are present (and the quality of reference peaks for them) and finally the software code (... the spectrometer you are using). There is no simple answer possible. The better approach for the quality of a quantitative analysis would be the calculation of final result-error for each element (including the deconvolution error).
Name: Jay Otts
Date: Tuesday 2005-09-06 15:33:21
Email: jayotts@comcast.net
Message (question/answer):
For a standardless EDX quantitative analysis, what Chi Square values are acceptable?
Name: Frank Eggert
Date: Thursday 2005-06-09 22:30:19
Email: eggert@mikroanalytik.de
Message (question/answer):
The hint of Lolo Flores is ready considered and the problem is fixed with version 1.12. (advertisement takes not longer the focus during inputs). With continued running time of the program the advertisement comes more rarely, now. I hope, it helps.
Name: -
Date: Saturday 2005-04-30 07:03:45
Email: -
Message (question/answer):
Electron Microscopy at the University of Munich
The Department of Chemistry and Biochemistry at the University of Munich intends to fill two positions at the Center for Electron Microscopy. The Center supports various research groups with projects related to the application of electron microscopy.
a) An electron microscopist to be in charge of the Center for Electron Microscopy. The responsibilities of this position include examinations via scanning and transmission electron microscopy, teaching and training of users, as well as support in the future development of the facility. Applicants should have a degree in physics, materials science or chemistry, an excellent background and experience in electron microscopy, and the ability to work in an interdisciplinary team. Salary will be according to the BAT IIa scale.
b) An engineer or physicist to be in charge of the technical support of the electron microscopes and to study materials as well as biological samples using transmission electron microscopy and scanning electron microscopy (including preparation).
Applicants should have a degree in engineering or a similar qualification and gained experience in electrical engineering and vacuum technology. It would be desirable to have a background in electron microscopy and materials science. Salary will be according to the BAT III scale.
We offer a wide spectrum of activities in a dynamic environment with a modern infrastructure and look forward to your application. Disabled persons with the same qualifications will be given preference. Please send your applications before May 31st, 2005 to: Professor Thomas Bein, Department of Chemistry and Biochemistry at the Ludwig-Maximilians-University, Munich, Butenandtstr. 5-13 (E), 81377 Munich, Tel. 089-2180-77623, Fax -77622, tbein@cup.uni-muenchen.de
Name: Frank Eggert
Date: Saturday 2005-03-26 08:24:03
Email: eggert@mikroanalytik.de
Message (question/answer):
I tried to check, what you meant. Indeed, the focus do really change only with text inputs (e.g. energy to search EDX X-ray line overlaps). I\'m going to fix the problem (or to provide an improved solution for this problem).
Name: lolo flores
Date: Wednesday 2005-03-23 14:21:31
Email: without
Message (question/answer):
Hi there;
The software is excellent, a very nice job.
There is only one thing: the pop up window
with the adds (or the lack of them) takes
the focus. I do not mind the advertisements
but it�s really annoying if it takes the mouse
focus while I�m doing something else.
Hope you can fix it.
Name: service
Date: Wednesday 2004-05-12 08:35:56
Email: service@mikroanalytik.de
Message (question/answer):
Dear David, it should work. More than 100 people have already installed MA-table successfully. May be, the file was injured. Please download the ZIP-file, once again.
Name: David Cousens
Date: Wednesday 2004-05-12 04:35:54
Email: David.Cousens@csiro.au
Message (question/answer):
Hi
I am unable to unzip the database file with Winzip. I get a message saying invalid archive. Is this a known problem?
Name: Frank Eggert
Date: Tuesday 2004-02-10 21:53:53
Email: eggert@mikroanalytik.de
Message (question/answer):
... I found and fixed the problem. For some users the program has produced wrong registration codes (for every tenth!). There is a new version of MA-Table for download (1.05). This version should manage the problem and has fixed the bug. You have to install MA-Table once again.
I have to apologize. For users with problems again, please contact me directly and give me the registration code for checking.
Name: Frank Eggert
Date: Saturday 2004-02-07 09:06:43
Email: eggert@mikroanalytik.de
Message (question/answer):
Obviously there are some problems with free of charge registration. I\'m going to check this. If there are improvements, then I will post it here.
Name: Bruce
Date: Friday 2004-02-06 07:59:50
Email: without
Message (question/answer):
The software sucks!! When I try to get registered, each time it gave me different codes and non of them worked....all \\\"code not valid\\\"!!!
Name: Frank Eggert
Date: Friday 2003-06-13 00:28:29
Email: eggert@mikroanalytik.de
Message (question/answer):
Welcome for questions and discussion in the microanalyst.net internet portal.
You should try it!