Is this no good?
Better, but not as good as I hope for. As far as I know the scintillator material has the following FWHM:
CsJ(TI): 10-12 %
NaJ(TI): 8-9 %
CsI(TI): 6-7 %
I already are using CsJ(TI) scintillators. The NaJ(TI) (in your link) is an improvement but CsI(TI) is the one I want.
No comment about the car?! I thought you would want to take a ride with me in Poland… 
Hi. I have a complete gamma spec you can borrow for as long as you need it..
Thanks Alan, very nice of you. However I have already built all the electronic and data acquisition software for the radiation spectrometer. It’s an integrated system together with other sensors (over Ethernet) and a common database. The goal I want to achieve is to increase the resolution of the current device by change the scintillation crystal.
By the way, what do you think about the picture on my new T-shirt I plan to use this summer?
Regards
Bo, SM6FIE
.PS Please note that I have taken the original photo from the Internet and that it can be copy protected. I will contact them and see if they will allow me to use the photo to move the boundaries forward for Cold Fusion.
Does anybody know where I can buy a CsI(TI) scintillation crystal to a good (cheap) price? I currently use CsJ(TI) but this crystal has an FWHM of about 12%. The CsI(TI) is typically in the range of 6-7%.
I have of course checked sites like eBay etc. but have not been able to find an offer that fits the budget. Any advice, tips etc. are appreciated.
Regards
/Bo, SM6FIE
If you produce high energy neutrons e.g. if you get 3-He then classic shields will increase the neutron flux up to 10x and not decrease it!! Same for muons!
Use water filled pet bottles to shield neutrons!
Thanks for the tip about the paper/book, interesting reading. Good catch! However I’m a little confused about your statement to use “Use water filled pet bottles to shield neutrons!”. Reading the conclusion of the report it seems that Iron would be a must better choice, see text snippets below.
“Our analysis concludes that the common belief that more material is better holds up well when considering low-Z hydrogenous materials for cosmic shields. The hydrogenous materials modeled for this study were polyethylene (PE), borated polyethylene (BPE), and water. The effectiveness of each of these materials in shielding cosmic neutrons, protons and muons was similarly poor.”
“Iron proves to be optimum better material than lead since it has a lower rate of Secondary neutron production. For a given thickness, iron outperforms lead by a factor of 5 and hydrogenous materials on average by a factor of 20, making it the shielding material of choice for neutrons above 20 MeV.”
See figure below.
Finally, what do you mean by classic shields will increase the neutron flux up to a factor 10X? Can you clarify what you mean?
Regards
Bo, SM6FIE
Eventually some experimenters will find the following utility to be useful in their work.
The intention of this utility application is to be able to collect data from up to four DMM’s and simultaneously measure and collect data. Data for each DMM is presented on the PC and a graph can be shown of the collected data. Data can also be saved to a CSV file or database for later analyze.
The main goal was to be able to quickly set up the system to catch several parameters from an experiment like volt, current, temperature, resistance etc. No programing is necessary, just plug and go. A schematic sketch is shown in below:
If you are interested to get a copy of the application please contact the author and I will send a Zip file with the necessary files.
Attached is a PDF file that describes the application closer in some details.
Regards
Bo, SM6FIE
Display MoreBeen looking at details for the scope of independent replication. Started to brainstorm about cell construction and candidates for BOM. I think I found an easy cheap way and went ahead to modeling it tho show you:
It's a draft, please imagine in the missing HV insulation and gas ports.
Features such as see-through and gap adjustment were considered, and it should hold the gas in, I guess. I wouldn't bet any money on that gap adjustment solution, but I thought it's still better than no adjustment.
What do you think?
FreeCad?
The 1400V max is a problem. The input to George's device is anything up to 3kV, the output is higher. But it does look like a nice piece of kit.
A quick and dirty method would be to modify the input circuit of the probe. Typically the input circuit looks like the schematic below. You could for example change R19 and R78 from 1 Mohm to say 9.1 Mohm. These resistors need to be handpicked and closely matched. They are probably of the SMD 1208 type so it should be a fairly easy task to replace them.
This will have the effect of scaling up the max voltage with a factor of about 3 (3.030). So now you are in the position to be able to cover the primary voltage span you are interested of. Of course there is some safety issues involved in this that has to be considered. The frequency response and CMRR will be affected. So it would be wise to do a total recalibration and test. Eventually also tweak the RC part of the input circuit.
/Bo, SM6FIE
Quote
I am in the market for a high voltage high frequency scope probe (about 1000:1) . Most - even 'used' ones are in excess of $1000.00 . I have one similar already, but it's only good for low frequency use - up to 60Hz..
Hi!
I could recommend the HVP70 70 MHz differential probe from EEVBLOG. The quality of the product is excellent. They recently had a ”sales promotion” with a good discount. I gave about 270 US $. However I don’t know if that offer is still available. The general specs. Are as follows:
Bandwidth DC to 70MHz (-3dB)
Attenuation Ratio 1:10/100
Accuracy ±1%
Rise Time: 5ns
Input
Impedance 4 MΩ, 5.5pF each side to ground
Category CAT III
Differential Range ±70V (DC+AC Peak) and 70Vrms @1/10
±700V (DC+AC Peak) and 700Vrms @1/100
Common Mode Range ±700V (DC+AC Peak) and 700Vrms @1/10 & 1/100
Absolute Max. Voltage ±1400V (DC+AC Peak) and 1000Vrms @1/10 & 1/100 (Differential or Common Mode)
Output
Swing ±7V (into 50
Offset (typical) <±5mV
Noise (typical) 1.5mVrms
Source Impedance (typical) 50Ω (for using 1M input system oscilloscope)
CMRR (typical) -80dB @ 50Hz, -60dB @20kHz -50dB @1MHz, -40dB @ 10MHz
Here is a link: https://www.eevblog.com/product/hvp70/
Reagards
Bo, SM6FIE
Here is an update (see attached PDF) with 0.1 mF capacitators and some other reflections about your measurement problem.
/Bo, SM6FIE
I did some simulations based on the parameters given. See attached PDF file.
Regards
Bo, SM6FIE
The following simulations was done with National Instruments Ni Multisim 11.pdf
