On 11/24/2023 19:22, Joe Gwinn wrote:> On Thu, 23 Nov 2023 15:50:43 -0800, John Larkin <jl@997PotHill.com> > wrote: > >> On Thu, 23 Nov 2023 23:32:35 +0200, Dimiter_Popoff <dp@tgi-sci.com> >> wrote: >> >>> On 11/23/2023 23:13, John Larkin wrote: >>>> On Thu, 23 Nov 2023 23:04:47 +0200, Dimiter_Popoff <dp@tgi-sci.com> >>>> wrote: >>>> >>>>> On 11/21/2023 5:52, John Larkin wrote: >>>>>> >>>>>> There's an electronics assembly joint near us that's going out of >>>>>> business, so we poached three employees and a bunch of equipment. I've >>>>>> always wanted a high-res xray, and I got one and the guy to run it. >>>>>> >>>>>> https://www.dropbox.com/scl/fo/lfdot6a64pg05z2x1ejo1/h?rlkey=p8lmnoy9388d3v20qv5a8qgwf&dl=0 >>>>>> >>>>>> We also got a 3D AOI board inspection machine which makes equally cool >>>>>> images. >>>>>> >>>>> >>>>> Really cool. How long does it take it to scan things, say that PLCC 20 >>>>> part? Resolution looks impressive. >>>>> Can you post a photo of the entire thing? >>>> >>>> I didn't do it, but I think the images are immediate, real-time. I >>>> think they can make movies too. >>> >>> Now this is even more impressive. Are the images directly digitized? >>> I mean CAT scanner like? >> >> I don't know the technology. Maybe a fluorescent sceen and a camera? >> Or some exotic sensor technology? > > Yes. I remembered that it was a CsI screen and an area photo sensor, > but much has changed since I last thought about this, so I did some > digging. > > >> Dentists are using video imagers and not film any more. I wonder how >> that sensor works. > > From Dentron, a Dental X-Ray Sensor manufacturer: "The Dentron Direct > USB sensor offers rounded corners, smooth edges, and two sizes (size > #1 for children | size #2 for adults) to optimize patient comfort > while receiving a dental X-Ray. The thin, tough, and durable > polyamide housing is less than 1/4" and features a CMOS imaging sensor > chip, CSI Scintillator, electronic circuits, shielding foils, and > polyurethane cable and shock absorbers."Thanks for doing the research. So it looks like they have some scintillating foil screen and a "normal" photosensor, not bad at all.
new x-ray machine
Started by ●November 20, 2023
Reply by ●November 24, 20232023-11-24
Reply by ●November 24, 20232023-11-24
On Thu, 23 Nov 2023 15:50:43 -0800, John Larkin <jl@997PotHill.com> wrote:>On Thu, 23 Nov 2023 23:32:35 +0200, Dimiter_Popoff <dp@tgi-sci.com> >wrote: > >>On 11/23/2023 23:13, John Larkin wrote: >>> On Thu, 23 Nov 2023 23:04:47 +0200, Dimiter_Popoff <dp@tgi-sci.com> >>> wrote: >>> >>>> On 11/21/2023 5:52, John Larkin wrote: >>>>> >>>>> There's an electronics assembly joint near us that's going out of >>>>> business, so we poached three employees and a bunch of equipment. I've >>>>> always wanted a high-res xray, and I got one and the guy to run it. >>>>> >>>>> https://www.dropbox.com/scl/fo/lfdot6a64pg05z2x1ejo1/h?rlkey=p8lmnoy9388d3v20qv5a8qgwf&dl=0 >>>>> >>>>> We also got a 3D AOI board inspection machine which makes equally cool >>>>> images. >>>>> >>>> >>>> Really cool. How long does it take it to scan things, say that PLCC 20 >>>> part? Resolution looks impressive. >>>> Can you post a photo of the entire thing? >>> >>> I didn't do it, but I think the images are immediate, real-time. I >>> think they can make movies too. >> >>Now this is even more impressive. Are the images directly digitized? >>I mean CAT scanner like? > >I don't know the technology. Maybe a fluorescent sceen and a camera? >Or some exotic sensor technology? > >Dentists are using video imagers and not film any more. I wonder how >that sensor works. > >> >> >>> >>> Do you want to see the PLCC in a full-field view? Or the whole board? >>> I'll ask Garvin to do that. >>> >> >>I meant the entire machine, from outside - have never seen one. > >Ok, OK. Will do. > >We have another, older Xray machine. It counts parts on reels but >doesn't have the resolution to see what's inside parts.I came in to work on Black Friday to take some boards out of an oven, so shot these: https://www.dropbox.com/scl/fo/nbojo29b3i6b8i54c3mak/h?rlkey=ugvytgyg2y0bp1bfuw7xnls7c&dl=0 Looks expensive. I'll find out what we paid for it. The state of California made us install a bunch of dosimeters before we were officially allowed to use it.
Reply by ●November 24, 20232023-11-24
On Fri, 24 Nov 2023 23:04:50 +0200, Dimiter_Popoff <dp@tgi-sci.com> wrote:>On 11/24/2023 19:22, Joe Gwinn wrote: >> On Thu, 23 Nov 2023 15:50:43 -0800, John Larkin <jl@997PotHill.com> >> wrote: >> >>> On Thu, 23 Nov 2023 23:32:35 +0200, Dimiter_Popoff <dp@tgi-sci.com> >>> wrote: >>> >>>> On 11/23/2023 23:13, John Larkin wrote: >>>>> On Thu, 23 Nov 2023 23:04:47 +0200, Dimiter_Popoff <dp@tgi-sci.com> >>>>> wrote: >>>>> >>>>>> On 11/21/2023 5:52, John Larkin wrote: >>>>>>> >>>>>>> There's an electronics assembly joint near us that's going out of >>>>>>> business, so we poached three employees and a bunch of equipment. I've >>>>>>> always wanted a high-res xray, and I got one and the guy to run it. >>>>>>> >>>>>>> https://www.dropbox.com/scl/fo/lfdot6a64pg05z2x1ejo1/h?rlkey=p8lmnoy9388d3v20qv5a8qgwf&dl=0 >>>>>>> >>>>>>> We also got a 3D AOI board inspection machine which makes equally cool >>>>>>> images. >>>>>>> >>>>>> >>>>>> Really cool. How long does it take it to scan things, say that PLCC 20 >>>>>> part? Resolution looks impressive. >>>>>> Can you post a photo of the entire thing? >>>>> >>>>> I didn't do it, but I think the images are immediate, real-time. I >>>>> think they can make movies too. >>>> >>>> Now this is even more impressive. Are the images directly digitized? >>>> I mean CAT scanner like? >>> >>> I don't know the technology. Maybe a fluorescent sceen and a camera? >>> Or some exotic sensor technology? >> >> Yes. I remembered that it was a CsI screen and an area photo sensor, >> but much has changed since I last thought about this, so I did some >> digging. >> >> >>> Dentists are using video imagers and not film any more. I wonder how >>> that sensor works. >> >> From Dentron, a Dental X-Ray Sensor manufacturer: "The Dentron Direct >> USB sensor offers rounded corners, smooth edges, and two sizes (size >> #1 for children | size #2 for adults) to optimize patient comfort >> while receiving a dental X-Ray. The thin, tough, and durable >> polyamide housing is less than 1/4" and features a CMOS imaging sensor >> chip, CSI Scintillator, electronic circuits, shielding foils, and >> polyurethane cable and shock absorbers." > >Thanks for doing the research. So it looks like they have some >scintillating foil screen and a "normal" photosensor, not bad at all.Welcome. Today it's a fancy kind of Cesium Iodide film and a large-pixel (compared to those in SLR cameras) CMOS Image Sensor. You would probably find the various patents illuminating and perhaps useful. Joe Gwinn
Reply by ●November 24, 20232023-11-24
On Thursday, November 23, 2023 at 3:24:58 PM UTC-6, John Larkin wrote:> On Thu, 23 Nov 2023 12:42:34 -0800 (PST), Klaus Kragelund > <klaus.k...@gmail.com> wrote: > > >On Tuesday, 21 November 2023 at 04:53:36 UTC+1, John Larkin wrote: > >> There's an electronics assembly joint near us that's going out of > >> business, so we poached three employees and a bunch of equipment. I've > >> always wanted a high-res xray, and I got one and the guy to run it. > >> > >> https://www.dropbox.com/scl/fo/lfdot6a64pg05z2x1ejo1/h?rlkey=p8lmnoy9388d3v20qv5a8qgwf&dl=0 > >> > >> We also got a 3D AOI board inspection machine which makes equally cool > >> images. > >Congratulations. > > > >Those pictures of the DCDC converter looks like some chinese thrown together and potted to look nice. Is that right? > I think some dc/dc bricks are worse, just haywired parts gooped in a > shell. > > I love the Murata converter. The toroid core is interior to the PCB > and the vias are the windings. Isolation capacitance is very low. > > > >A big firm in Denmark went bankrupt, so I bought a lot of HP gear, 3 VNAs, 1 EMC test receiver, a 4GHz signal generator, a microscope, .... all for 6000 USD. > >Only one of them doesn't work > Sine waves are booooooring.At my age I don't need the excitement of TD stuff. I want booooooring.
Reply by ●November 25, 20232023-11-25
On a sunny day (Fri, 24 Nov 2023 23:04:50 +0200) it happened Dimiter_Popoff <dp@tgi-sci.com> wrote in <ujr35j$2fd7a$1@dont-email.me>:>On 11/24/2023 19:22, Joe Gwinn wrote: >> On Thu, 23 Nov 2023 15:50:43 -0800, John Larkin <jl@997PotHill.com> >> wrote: >> >>> On Thu, 23 Nov 2023 23:32:35 +0200, Dimiter_Popoff <dp@tgi-sci.com> >>> wrote: >>> >>>> On 11/23/2023 23:13, John Larkin wrote: >>>>> On Thu, 23 Nov 2023 23:04:47 +0200, Dimiter_Popoff <dp@tgi-sci.com> >>>>> wrote: >>>>> >>>>>> On 11/21/2023 5:52, John Larkin wrote: >>>>>>> >>>>>>> There's an electronics assembly joint near us that's going out of >>>>>>> business, so we poached three employees and a bunch of equipment. I've >>>>>>> always wanted a high-res xray, and I got one and the guy to run it. >>>>>>> >>>>>>> https://www.dropbox.com/scl/fo/lfdot6a64pg05z2x1ejo1/h?rlkey=p8lmnoy9388d3v20qv5a8qgwf&dl=0 >>>>>>> >>>>>>> We also got a 3D AOI board inspection machine which makes equally cool >>>>>>> images. >>>>>>> >>>>>> >>>>>> Really cool. How long does it take it to scan things, say that PLCC 20 >>>>>> part? Resolution looks impressive. >>>>>> Can you post a photo of the entire thing? >>>>> >>>>> I didn't do it, but I think the images are immediate, real-time. I >>>>> think they can make movies too. >>>> >>>> Now this is even more impressive. Are the images directly digitized? >>>> I mean CAT scanner like? >>> >>> I don't know the technology. Maybe a fluorescent sceen and a camera? >>> Or some exotic sensor technology? >> >> Yes. I remembered that it was a CsI screen and an area photo sensor, >> but much has changed since I last thought about this, so I did some >> digging. >> >> >>> Dentists are using video imagers and not film any more. I wonder how >>> that sensor works. >> >> From Dentron, a Dental X-Ray Sensor manufacturer: "The Dentron Direct >> USB sensor offers rounded corners, smooth edges, and two sizes (size >> #1 for children | size #2 for adults) to optimize patient comfort >> while receiving a dental X-Ray. The thin, tough, and durable >> polyamide housing is less than 1/4" and features a CMOS imaging sensor >> chip, CSI Scintillator, electronic circuits, shielding foils, and >> polyurethane cable and shock absorbers." > >Thanks for doing the research. So it looks like they have some >scintillating foil screen and a "normal" photosensor, not bad at all.4k is a lot of dollars there is plenty on the web for creating your own xrays, for example: https://hackaday.com/2015/12/31/portable-diy-radiography/ looks like my PMT supply will work! In the old tube days the HV parallel regulator tubes in color TVs also emitted xrays an PD500 tube is all you need: http://www.kronjaeger.com/hv-old/xray/tech/PD500/ I still have some scintillator screen, plenty of cameras. Maybe one day I know about one guy at work who got xray burns working on a color TV with the protection screen around the HV tube removed. After that firebrigade came and tested all color monitors in the studios for radiation.
Reply by ●November 25, 20232023-11-25
On Sat, 25 Nov 2023 05:52:11 GMT, Jan Panteltje <alien@comet.invalid> wrote:>On a sunny day (Fri, 24 Nov 2023 23:04:50 +0200) it happened Dimiter_Popoff ><dp@tgi-sci.com> wrote in <ujr35j$2fd7a$1@dont-email.me>: > >>On 11/24/2023 19:22, Joe Gwinn wrote: >>> On Thu, 23 Nov 2023 15:50:43 -0800, John Larkin <jl@997PotHill.com> >>> wrote: >>> >>>> On Thu, 23 Nov 2023 23:32:35 +0200, Dimiter_Popoff <dp@tgi-sci.com> >>>> wrote: >>>> >>>>> On 11/23/2023 23:13, John Larkin wrote: >>>>>> On Thu, 23 Nov 2023 23:04:47 +0200, Dimiter_Popoff <dp@tgi-sci.com> >>>>>> wrote: >>>>>> >>>>>>> On 11/21/2023 5:52, John Larkin wrote: >>>>>>>> >>>>>>>> There's an electronics assembly joint near us that's going out of >>>>>>>> business, so we poached three employees and a bunch of equipment. I've >>>>>>>> always wanted a high-res xray, and I got one and the guy to run it. >>>>>>>> >>>>>>>> <https://www.dropbox.com/scl/fo/lfdot6a64pg05z2x1ejo1/h?rlkey=p8lmnoy9388d3v20qv5a8qgwf&dl=0> >>>>>>>> >>>>>>>> We also got a 3D AOI board inspection machine which makes equally cool >>>>>>>> images. >>>>>>>> >>>>>>> >>>>>>> Really cool. How long does it take it to scan things, say that PLCC 20 >>>>>>> part? Resolution looks impressive. >>>>>>> Can you post a photo of the entire thing? >>>>>> >>>>>> I didn't do it, but I think the images are immediate, real-time. I >>>>>> think they can make movies too. >>>>> >>>>> Now this is even more impressive. Are the images directly digitized? >>>>> I mean CAT scanner like? >>>> >>>> I don't know the technology. Maybe a fluorescent sceen and a camera? >>>> Or some exotic sensor technology? >>> >>> Yes. I remembered that it was a CsI screen and an area photo sensor, >>> but much has changed since I last thought about this, so I did some >>> digging. >>> >>> >>>> Dentists are using video imagers and not film any more. I wonder how >>>> that sensor works. >>> >>> From Dentron, a Dental X-Ray Sensor manufacturer: "The Dentron Direct >>> USB sensor offers rounded corners, smooth edges, and two sizes (size >>> #1 for children | size #2 for adults) to optimize patient comfort >>> while receiving a dental X-Ray. The thin, tough, and durable >>> polyamide housing is less than 1/4" and features a CMOS imaging sensor >>> chip, CSI Scintillator, electronic circuits, shielding foils, and >>> polyurethane cable and shock absorbers." >> >>Thanks for doing the research. So it looks like they have some >>scintillating foil screen and a "normal" photosensor, not bad at all. > >4k is a lot of dollars >there is plenty on the web for creating your own xrays, for example: > <https://hackaday.com/2015/12/31/portable-diy-radiography/> > looks like my PMT supply will work!Umm, I think I'll pass on the PMT's - the dental sensor is for use inside the patient's mouth. A kilovolt across the tongue will command attention. Also seems a bit large to fit inside a human mouth.>In the old tube days the HV parallel regulator tubes in color TVs also emitted xrays >an PD500 tube is all you need: > <http://www.kronjaeger.com/hv-old/xray/tech/PD500/> >I still have some scintillator screen, plenty of cameras. >Maybe one day >I know about one guy at work who got xray burns working on a color TV with the protection screen around the HV tube removed. >After that firebrigade came and tested all color monitors in the studios for radiation.I would not have thought this possible for lack of sufficient 30 KV X-ray flux, but 30 KV would definitely cause skin burns, as it won't penetrate any farther in water than the skin. Joe Gwinn
Reply by ●November 25, 20232023-11-25
On Sat, 25 Nov 2023 05:52:11 GMT, Jan Panteltje <alien@comet.invalid> wrote:>On a sunny day (Fri, 24 Nov 2023 23:04:50 +0200) it happened Dimiter_Popoff ><dp@tgi-sci.com> wrote in <ujr35j$2fd7a$1@dont-email.me>: > >>On 11/24/2023 19:22, Joe Gwinn wrote: >>> On Thu, 23 Nov 2023 15:50:43 -0800, John Larkin <jl@997PotHill.com> >>> wrote: >>> >>>> On Thu, 23 Nov 2023 23:32:35 +0200, Dimiter_Popoff <dp@tgi-sci.com> >>>> wrote: >>>> >>>>> On 11/23/2023 23:13, John Larkin wrote: >>>>>> On Thu, 23 Nov 2023 23:04:47 +0200, Dimiter_Popoff <dp@tgi-sci.com> >>>>>> wrote: >>>>>> >>>>>>> On 11/21/2023 5:52, John Larkin wrote: >>>>>>>> >>>>>>>> There's an electronics assembly joint near us that's going out of >>>>>>>> business, so we poached three employees and a bunch of equipment. I've >>>>>>>> always wanted a high-res xray, and I got one and the guy to run it. >>>>>>>> >>>>>>>> https://www.dropbox.com/scl/fo/lfdot6a64pg05z2x1ejo1/h?rlkey=p8lmnoy9388d3v20qv5a8qgwf&dl=0 >>>>>>>> >>>>>>>> We also got a 3D AOI board inspection machine which makes equally cool >>>>>>>> images. >>>>>>>> >>>>>>> >>>>>>> Really cool. How long does it take it to scan things, say that PLCC 20 >>>>>>> part? Resolution looks impressive. >>>>>>> Can you post a photo of the entire thing? >>>>>> >>>>>> I didn't do it, but I think the images are immediate, real-time. I >>>>>> think they can make movies too. >>>>> >>>>> Now this is even more impressive. Are the images directly digitized? >>>>> I mean CAT scanner like? >>>> >>>> I don't know the technology. Maybe a fluorescent sceen and a camera? >>>> Or some exotic sensor technology? >>> >>> Yes. I remembered that it was a CsI screen and an area photo sensor, >>> but much has changed since I last thought about this, so I did some >>> digging. >>> >>> >>>> Dentists are using video imagers and not film any more. I wonder how >>>> that sensor works. >>> >>> From Dentron, a Dental X-Ray Sensor manufacturer: "The Dentron Direct >>> USB sensor offers rounded corners, smooth edges, and two sizes (size >>> #1 for children | size #2 for adults) to optimize patient comfort >>> while receiving a dental X-Ray. The thin, tough, and durable >>> polyamide housing is less than 1/4" and features a CMOS imaging sensor >>> chip, CSI Scintillator, electronic circuits, shielding foils, and >>> polyurethane cable and shock absorbers." >> >>Thanks for doing the research. So it looks like they have some >>scintillating foil screen and a "normal" photosensor, not bad at all. > >4k is a lot of dollars >there is plenty on the web for creating your own xrays, for example: > https://hackaday.com/2015/12/31/portable-diy-radiography/ > looks like my PMT supply will work! >In the old tube days the HV parallel regulator tubes in color TVs also emitted xrays >an PD500 tube is all you need: > http://www.kronjaeger.com/hv-old/xray/tech/PD500/ >I still have some scintillator screen, plenty of cameras. >Maybe one day >I know about one guy at work who got xray burns working on a color TV with the protection screen around the HV tube removed. >After that firebrigade came and tested all color monitors in the studios for radiation.For decent imaging, you need a point source of x-rays, which you get from blasting a tiny electron beam at a metal target. The best results happen when you're at the edge of melting the metal.
Reply by ●November 25, 20232023-11-25
On Sunday, November 26, 2023 at 2:00:31 AM UTC+11, John Larkin wrote:> On Sat, 25 Nov 2023 05:52:11 GMT, Jan Panteltje <al...@comet.invalid> wrote: > >On a sunny day (Fri, 24 Nov 2023 23:04:50 +0200) it happened Dimiter_Popoff <d...@tgi-sci.com> wrote in <ujr35j$2fd7a$1...@dont-email.me>: > >>On 11/24/2023 19:22, Joe Gwinn wrote: > >>> On Thu, 23 Nov 2023 15:50:43 -0800, John Larkin <j...@997PotHill.com> wrote: > >>>> On Thu, 23 Nov 2023 23:32:35 +0200, Dimiter_Popoff <d...@tgi-sci.com> wrote: > >>>>> On 11/23/2023 23:13, John Larkin wrote: > >>>>>> On Thu, 23 Nov 2023 23:04:47 +0200, Dimiter_Popoff <d...@tgi-sci.com> wrote: > >>>>>>> On 11/21/2023 5:52, John Larkin wrote:> For decent imaging, you need a point source of x-rays, which you get from blasting a tiny electron beam at a metal target. The best results happen when you're at the edge of melting the metal.Electron microscopes get their tiny electron spot by focussing the beam onto a point. The brightest electron sources are cold field emission guns, which are very unstable. Hot field emitters are almost as bright because the source gets warm enough to get shaped into a sharp spike by the electric field. Both need a very high vacuum in the source because positive ion bombardment degrades the emitter very rapidly. For routine use a single crystal of lanthanum boride is bright enough, and lasts for about six months, in a hard vacuum. -- Bill Sloman, Sydney
Reply by ●November 25, 20232023-11-25
On a sunny day (Sat, 25 Nov 2023 06:59:35 -0800) it happened John Larkin <jl@997PotHill.com> wrote in <eq24mitq9r7sgc73mgaqlovulior2uaht1@4ax.com>:>On Sat, 25 Nov 2023 05:52:11 GMT, Jan Panteltje <alien@comet.invalid> >wrote: > >>On a sunny day (Fri, 24 Nov 2023 23:04:50 +0200) it happened Dimiter_Popoff >><dp@tgi-sci.com> wrote in <ujr35j$2fd7a$1@dont-email.me>: >> >>>On 11/24/2023 19:22, Joe Gwinn wrote: >>>> On Thu, 23 Nov 2023 15:50:43 -0800, John Larkin <jl@997PotHill.com> >>>> wrote: >>>> >>>>> On Thu, 23 Nov 2023 23:32:35 +0200, Dimiter_Popoff <dp@tgi-sci.com> >>>>> wrote: >>>>> >>>>>> On 11/23/2023 23:13, John Larkin wrote: >>>>>>> On Thu, 23 Nov 2023 23:04:47 +0200, Dimiter_Popoff <dp@tgi-sci.com> >>>>>>> wrote: >>>>>>> >>>>>>>> On 11/21/2023 5:52, John Larkin wrote: >>>>>>>>> >>>>>>>>> There's an electronics assembly joint near us that's going out of >>>>>>>>> business, so we poached three employees and a bunch of equipment. I've >>>>>>>>> always wanted a high-res xray, and I got one and the guy to run it. >>>>>>>>> >>>>>>>>> https://www.dropbox.com/scl/fo/lfdot6a64pg05z2x1ejo1/h?rlkey=p8lmnoy9388d3v20qv5a8qgwf&dl=0 >>>>>>>>> >>>>>>>>> We also got a 3D AOI board inspection machine which makes equally cool >>>>>>>>> images. >>>>>>>>> >>>>>>>> >>>>>>>> Really cool. How long does it take it to scan things, say that PLCC 20 >>>>>>>> part? Resolution looks impressive. >>>>>>>> Can you post a photo of the entire thing? >>>>>>> >>>>>>> I didn't do it, but I think the images are immediate, real-time. I >>>>>>> think they can make movies too. >>>>>> >>>>>> Now this is even more impressive. Are the images directly digitized? >>>>>> I mean CAT scanner like? >>>>> >>>>> I don't know the technology. Maybe a fluorescent sceen and a camera? >>>>> Or some exotic sensor technology? >>>> >>>> Yes. I remembered that it was a CsI screen and an area photo sensor, >>>> but much has changed since I last thought about this, so I did some >>>> digging. >>>> >>>> >>>>> Dentists are using video imagers and not film any more. I wonder how >>>>> that sensor works. >>>> >>>> From Dentron, a Dental X-Ray Sensor manufacturer: "The Dentron Direct >>>> USB sensor offers rounded corners, smooth edges, and two sizes (size >>>> #1 for children | size #2 for adults) to optimize patient comfort >>>> while receiving a dental X-Ray. The thin, tough, and durable >>>> polyamide housing is less than 1/4" and features a CMOS imaging sensor >>>> chip, CSI Scintillator, electronic circuits, shielding foils, and >>>> polyurethane cable and shock absorbers." >>> >>>Thanks for doing the research. So it looks like they have some >>>scintillating foil screen and a "normal" photosensor, not bad at all. >> >>4k is a lot of dollars >>there is plenty on the web for creating your own xrays, for example: >> https://hackaday.com/2015/12/31/portable-diy-radiography/ >> looks like my PMT supply will work! >>In the old tube days the HV parallel regulator tubes in color TVs also emitted xrays >>an PD500 tube is all you need: >> http://www.kronjaeger.com/hv-old/xray/tech/PD500/ >>I still have some scintillator screen, plenty of cameras. >>Maybe one day >>I know about one guy at work who got xray burns working on a color TV with the protection screen around the HV tube removed. >>After that firebrigade came and tested all color monitors in the studios for radiation. > >For decent imaging, you need a point source of x-rays, which you get >from blasting a tiny electron beam at a metal target. The best results >happen when you're at the edge of melting the metal.I just found this: https://community.element14.com/members-area/personalblogs/b/linas-karpavicius-s-blog/posts/homemade-high-resolution-x-ray-scanner nice pictures, 35 kV ? There is a lot on the web,
Reply by ●November 25, 20232023-11-25
On 11/25/2023 18:08, Anthony William Sloman wrote:> On Sunday, November 26, 2023 at 2:00:31 AM UTC+11, John Larkin wrote: >> On Sat, 25 Nov 2023 05:52:11 GMT, Jan Panteltje <al...@comet.invalid> wrote: >>> On a sunny day (Fri, 24 Nov 2023 23:04:50 +0200) it happened Dimiter_Popoff <d...@tgi-sci.com> wrote in <ujr35j$2fd7a$1...@dont-email.me>: >>>> On 11/24/2023 19:22, Joe Gwinn wrote: >>>>> On Thu, 23 Nov 2023 15:50:43 -0800, John Larkin <j...@997PotHill.com> wrote: >>>>>> On Thu, 23 Nov 2023 23:32:35 +0200, Dimiter_Popoff <d...@tgi-sci.com> wrote: >>>>>>> On 11/23/2023 23:13, John Larkin wrote: >>>>>>>> On Thu, 23 Nov 2023 23:04:47 +0200, Dimiter_Popoff <d...@tgi-sci.com> wrote: >>>>>>>>> On 11/21/2023 5:52, John Larkin wrote: > >> For decent imaging, you need a point source of x-rays, which you get from blasting a tiny electron beam at a metal target. The best results happen when you're at the edge of melting the metal. > > Electron microscopes get their tiny electron spot by focussing the beam onto a point. > > The brightest electron sources are cold field emission guns, which are very unstable. Hot field emitters are almost as bright because the source gets warm enough to get shaped into a sharp spike by the electric field. Both need a very high vacuum in the source because positive ion bombardment degrades the emitter very rapidly. > > For routine use a single crystal of lanthanum boride is bright enough, and lasts for about six months, in a hard vacuum. >I was wondering exactly if they were doing scanning point by point with a thin beam or something else - turned out it is "something else", Jan posted a link to a DYI project which uses a Hamamatsu 2400x2400 dots 0.05mm pitched sensor, must be something of the sort with a scintillating foil in front or sort of. Focusing x-rays is by far not as doable as it is with electrons, then who knows, may be scanning with an electron beam a plate to do x-ray at the point of scanning... not sure if it is practical, I am at home only with measuring gamma/x-ray spectra, not with making sources.
