Re: [Ifeffit] current-amp recommendation
HI Matthew: One possibility is the Caen quad amplifier that they made for BPMs. http://www.caenels.com/products/tetramm/ Carlo On Tue, 14 Nov 2017, Matthew Marcus wrote: I've gotten involved with a project in which stabilization of the position of a monochromatic, soft X-ray beam is needed. The offending frequencies seem to be vibration frequencies like 57 and 116Hz. We have in mind to use a thin Au film with a gap in the middle, measuring the drain current from the films, much as people normally use the jaws of slits. Now, I'd like to find a couple of current amplifiers which are small enough so that they can be connected with very short cables to the BNC connectors on the air-side of this detector, and which would have decent frequency response and low noise with inputs of the order of 0.1-1nA. Although this topic is outside the realm of XAFS analysis with IFEFFIT, I figure that people on this group might have some good experience. mam ___ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit Unsubscribe: http://millenia.cars.aps.anl.gov/mailman/options/ifeffit -- Carlo U. Segre -- Duchossois Leadership Professor of Physics Interim Chair, Department of Chemistry Director, Center for Synchrotron Radiation Research and Instrumentation Illinois Institute of Technology Voice: 312.567.3498Fax: 312.567.3494 se...@iit.edu http://phys.iit.edu/~segre se...@debian.org ___ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit Unsubscribe: http://millenia.cars.aps.anl.gov/mailman/options/ifeffit
Re: [Ifeffit] current-amp recommendation
Hi Matthew, At NSLS-II, we use a solution developed here at BNL for quad BPMs and other current-measurement operations. (I am using it for ion chambers at my beam line.) It is a box developed in the Instrumentation Division with a current amplifier, an A2D converter, and a microprocessor all inside a box that's about the size of a box of Pop Tarts. It has 4 SMA input channels and a single gain for all four channels. SMA to BNC cables are readily available from all the standard vendors. The output is an ethernet cable. The microprocessor runs a small debian system and starts an EPICS IOC and a DHCP client on boot. the 4 current get exposed as 4 PVs and the IOC does a lot of useful statistics on the fly. Seems to work pretty well. You could contact Pete Siddons. (Search for Siddons at the BNL website. When I tried it, the second hit was his staff page.) B On 11/14/2017 03:16 PM, Matthew Marcus wrote: I've gotten involved with a project in which stabilization of the position of a monochromatic, soft X-ray beam is needed. The offending frequencies seem to be vibration frequencies like 57 and 116Hz. We have in mind to use a thin Au film with a gap in the middle, measuring the drain current from the films, much as people normally use the jaws of slits. Now, I'd like to find a couple of current amplifiers which are small enough so that they can be connected with very short cables to the BNC connectors on the air-side of this detector, and which would have decent frequency response and low noise with inputs of the order of 0.1-1nA. Although this topic is outside the realm of XAFS analysis with IFEFFIT, I figure that people on this group might have some good experience. mam ___ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit Unsubscribe: http://millenia.cars.aps.anl.gov/mailman/options/ifeffit -- Bruce Ravel bra...@bnl.gov National Institute of Standards and Technology Synchrotron Science Group at NSLS-II Building 743, Room 114 Upton NY, 11973 Homepage:http://bruceravel.github.io/home/ Beamline:https://www.bnl.gov/ps/beamlines/beamline.php?r=6-BM Software:https://github.com/bruceravel Demeter: http://bruceravel.github.io/demeter/ ___ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit Unsubscribe: http://millenia.cars.aps.anl.gov/mailman/options/ifeffit
[Ifeffit] current-amp recommendation
I've gotten involved with a project in which stabilization of the position of a monochromatic, soft X-ray beam is needed. The offending frequencies seem to be vibration frequencies like 57 and 116Hz. We have in mind to use a thin Au film with a gap in the middle, measuring the drain current from the films, much as people normally use the jaws of slits. Now, I'd like to find a couple of current amplifiers which are small enough so that they can be connected with very short cables to the BNC connectors on the air-side of this detector, and which would have decent frequency response and low noise with inputs of the order of 0.1-1nA. Although this topic is outside the realm of XAFS analysis with IFEFFIT, I figure that people on this group might have some good experience. mam ___ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit Unsubscribe: http://millenia.cars.aps.anl.gov/mailman/options/ifeffit
