Hi Bob, The polycapillary lenses are not very efficient; I.E. they lose source energy in the process of focusing. If you are starting with a high intensity x-ray source, you can get a substantial amount focused into a 10-100 micron spot of high intensity. This is used in micro-XRF where a spot is illuminated by a high intensity, high energy source causing local ionization and when neutralization occurs, characteristic x-rays are emitted and measured typically with a silicon SDD detector. This type of lens is not used with the detectors due to its high loss.
The best detectors for low energy x-ray are probably the silicon detectors having a FWHM of about 120eV at 3.5 keV. However, NIST has a superconducting threshold spectroscopy technology that is the best in the world. Superconducting pixels are regulated to a temperature that is on the threshold of going out of the superconducting state. When a single photon hits, it heats the pixel enough that the change in its superconductive resistivity can be measured to provide how much energy was in the photon. They are probably able to measure to better than 0.1 eV the energy of the incident photon - I don't remember the actual spectral resolution. I remember when hearing of it that it was an absolutely phenomenal capability. It made HPGe look shabby. On Sun, Oct 27, 2019 at 9:56 AM [email protected] < [email protected]> wrote: > Bob— > > > > One such spectrometer is summarized here: > > > “Abstract > > Polycapillary X-ray optics (capillary X-ray lens) are now popular in X-ray > fluorescence (XRF) analysis. Such an X-ray lens can collect X-rays emitted > from an X-ray source in a large solid angle and form a very intense X-ray > microbeam which is very convenient for microbeam X-ray fluorescence (MXRF) > analysis giving low minimum detection limits (MDLs) in energy dispersive > X-ray fluorescence (EDXRF). A new method called position sensitive X-ray > spectrometry (PSXS) which combines an X-ray lens used to form an intense > XRF source and a position sensitive detector (PSD) used for wavelength > dispersive spectrometry (WDS) measurement was developed recently in the > X-ray Optics Laboratory of Institute of *Low Energy Nuclear Physics > (ILENP) at Beijing Normal University*. Such a method can give high energy > and spacial resolution and high detection efficiency simultaneously. A > short view of development of both the EDXRF using a capillary X-ray lens > and the new PSXS is given in this paper.” > > However the frequency sensitivity is not so good IMHO. It will take 4 or > 5 significant figures to help define/validate a good nuclear model and be > taken seriously as a nuclear source of a reasonable transition. The WDS > technology may achieve the sensitivity needed. > > > > Do you know the state -of-art probe frequency sensitivity? The paper > abstracted above is nearly 20 years old!!! > > > > Bob Cook > > > > > ------------------------------ > *From:* Bob Higgins <[email protected]> > *Sent:* Saturday, October 26, 2019 4:51:29 PM > *To:* [email protected] <[email protected]>; Jones Beene < > [email protected]> > *Subject:* Re: [Vo]:Nick Danger's Top 10 answers for symptom 7 > > @Jones Beene <[email protected]> The putative 3.5 keV is, of course, > detectable in pancake GM detectors and most x-ray sensors and > spectrometers. No esoteric detectors required for this. > > On Sat, Oct 26, 2019 at 8:48 AM Jones Beene <[email protected]> wrote: > > Of interest in the identification of LENR "mystery radiation" (if it is > found in the range of 3.5 keV) ... > > > > <http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> > Virus-free. > www.avg.com > <http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> > <#m_4945925743225898710_x_DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2> >
