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Neutron Club Application- Zan Chaudhry

Posted: Thu May 19, 2016 3:38 pm
by Zan_Chaudhry
Hi, I am Zan Chaudhry, an eighth grade student (just turned 14) in Howard County Maryland, and I have actually already completed a fusor. I'm just really into physics in general (experimental and theoretical of all types, but especially particle and nuclear). I built this completely on my own, but with funding from my parents. Most of my stuff is from eBay, but some of it comes from vacuum companies, some from my dad (he owns a medical equipment company), and the deuterium from my local Praxair distributor (really nice people) who happened to have a deuterium cylinder in stock and were willing to sell it to me; everyone else gave me a really hard time, especially Sigma Aldrich :(. I'm really sorry that I didn't join earlier, so I have not posted the images from earlier stages, but I can post them if they are needed. I just finished on Sunday and had the following data:
The test was carried out over a ten minute period.
Voltage:
~16.25 KV
Amperage:
~30 mA
Pressure:
I had a few different pressures, but mostly around 14 microns or 22 microns (my two main pressures at different times over 10 mins.)
Neutrons:
My 3He detector was having issues, so it would turn off after 30 seconds, but in that 30 seconds I had a neutron count of 646, so if it had run for the whole minute it would have been around 1,292 cpm. I repeated this a few times and got similar results (anywhere from 387 to 690 in 30 seconds, the average being around 650).

My pictures are attached. I also included an air plasma image at 35 micron (without diff pump, which I achieved earlier). If you have any doubts I have a full video too. Really excited to have done something like this :)!!

Re: Neutron Club Application- Zan Chaudhry

Posted: Thu May 19, 2016 4:44 pm
by Richard Hull
The count sounds a far too high for the voltage and current and pressure. I am deeply concerned about your settings related to the detection levle on the 3He tube.
The 3He tube will barely detect anything at 20kv.

You need to state a background count

You will need to run your fusor with the tube in and out of the moderator.

We need a lot more data.

Richard Hull

Re: Neutron Club Application- Zan Chaudhry

Posted: Thu May 19, 2016 5:29 pm
by Zan_Chaudhry
Hi Mr. Hull,

I ran a background before the test and got (average) 24 cpm. I just ran a background count for 30 seconds (I talked about the issues with my detector). I got 36 cpm and attached the video. The other fusor runs, in and out of moderater, I will post soon.

Re: Neutron Club Application- Zan Chaudhry

Posted: Thu May 19, 2016 6:39 pm
by Zan_Chaudhry
I tried to attach the video file but I can't upload mov files. So I have uploaded the file to onedrive and here is the link.

https://onedrive.live.com/redir?resid=1 ... ideo%2c3gp

Re: Neutron Club Application- Zan Chaudhry

Posted: Fri May 20, 2016 9:14 am
by Nick Peskosky
Zan,

Your background counts seem extremely high for an He-3 detector of the size shown in the attached images. With a moderator you would expect somewhere in the ballpark of 2-5 cpm depending on your geographic location and altitude. I'd recommend checking the tube against a strong Gamma emitter to ensure that you have the discriminator set properly. Your supply level seems a little low for the Fusor itself (as Richard stated) and I'm curious whether your tube is operating outside the proportional region. Could you please provide the detector model number (or gas fill parameter and dimensions) along with the bias voltage applied?

It does hurt your claim when you don't have a lot of background info on your project history. Keep pushing toward the end but just be aware that this board is very hesitant to add people to the neutron club in a push button fashion.

Re: Neutron Club Application- Zan Chaudhry

Posted: Fri May 20, 2016 1:44 pm
by Zan_Chaudhry
I'll try and see if I can use a gamma source from the nuclear medicine department of the hospital where my mom works. The voltage range is really high, from 2000-2800, and I run it at 2000. There's basically no information on the tube except for Operating voltage, model number, and the text neutron detector in Russian, and the model number, CH19H, does not turn up any results online.The tube is about 7.75 in. long and 1.25 in. diameter. I bought it off of eBay about a year ago. The background count that I reported was with the tube out of the moderator, however in the moderator the count was very similar. And again, I'm really sorry for not joining earlier.I'll do all I can to satisfy the board.

Re: Neutron Club Application- Zan Chaudhry

Posted: Fri May 20, 2016 6:03 pm
by Richard Hull
Nick is correct. You need to get your neutron counter working and not cutting off. No properly configured neutron counter ever just cuts off.

I operate a Reuter & Stokes, 23 inch, 4 atm.,3He tube and its bias is on the order of 1600 volts. The background here varies from 6-9 counts per minute. (cosmic radiation).

You need to
1. Get you counter working full time, properly biased and level discrimenated to count only neutrons
2. Take a background count over a period of ten minutes and then divide by ten to get your background CPM.
3. Run your fusor with the tube out of its moderator for 5 minutes - moderator not near the tube. report you counts per minute
4. Re-Run the fusor with the tube inside the moderator for 5 minutes and report your CPM.

I think you will find that once all is working well, that at 19kv, you will have to do a bit of statistics to prove you are doing fusion. You have a great tube, I think. It is far better than most ever have in their fusion quest, but it does take a bit of electronic shepherding to make it work within its design regime.

You probably should have joined a bit sooner to give us a bit of background on your effort as you went along. You are the very first person to ever show up here claiming a win in your first posting. It is only natural that your claims are looked at somewhat ascance by many old hands here. Russion made tubes are notoriously tough to get results from.

Richard Hull

Re: Neutron Club Application- Zan Chaudhry

Posted: Fri May 20, 2016 6:07 pm
by Jim Stead
I believe that first H in your tube model number is actually a Russian character that looks like a backwards N
Carl Willis posted info and a link to the specs for the tube you have - viewtopic.php?f=13&t=6196#p41096

Re: Neutron Club Application- Zan Chaudhry

Posted: Fri May 20, 2016 6:26 pm
by Richard Hull
Thanks Jim for finding this older posting. After reading it and the comments made by Doug Coulter, who claims experience with it, it sounds like a tube that needs a rather experienced hand to bring into useful and continued operation. Hopefully, someone with a small but stable neutron source.

A number of boron lined tubes are also famous for requiring an "experienced hand" to bring to heel in reliably counting neutrons.

But then all neutron counter tubes are not a simple thing for a rank amatuer with no electronics and specifically nuclear instrumention electronics experience to make a good, reliable neutron counter. I considered myself rather experienced and spent about 2 hours with a scope and neutron source to bring my preamp and NIM modules to the point of warranting only neutrons were counted.

Rolling your own neutron counter even with a good tube can be daunting for the amateur.

Richard Hull

Re: Neutron Club Application- Zan Chaudhry

Posted: Fri May 20, 2016 7:18 pm
by Zan_Chaudhry
Again, I'm really sorry for not joining earlier. I've been using fusor.net for a while, actually, and I found answers to all of my specific problems here. I never thought about joining because I was somewhat intimidated due to my lack of experience. I kept track of all of my progresses (and sadly, my failures too :(), and I'll work on compiling them to give the board all of my background (This includes 10's of pictures/videos). And I also have all of my purchases documented with a timeline. I really appreciate your guidance with my detector, and I'll follow through with everyone's advice. Also, thanks to Mr. Stead for noticing my model number and sharing the previous post with the specs.

Re: Neutron Club Application- Zan Chaudhry

Posted: Mon May 23, 2016 8:17 pm
by Zan_Chaudhry
I cleaned up my system a bit. I added a permanent camera with lead vests around the viewport. I got in contact with the nuclear medicine department, and they said that I can go use their Cs-137 on Thursday.

Re: Neutron Club Application- Zan Chaudhry

Posted: Fri Jul 29, 2016 7:01 pm
by Zan_Chaudhry
Sorry for not posting anything for so long, I've been gone for family reasons. But now I'm back, and I've got some work done. The testing of my neutron detector at the hospital was a complete failure due to a simple problem I didn't notice earlier. The wire was shorting randomly, and so the counts went crazy every once in a while. Now I've fixed that by replacing the wire, and I tested again (not with Cesium, just background) and my background was 4 cpm. I tested gamma sensitivity with a decent piece of Uranium ore and had no change in background. I still want to test again with Cesium, so I'll inquire at the hospital again. And for the fusor power, I have acquired an old x-ray transformer, which is meant to give out 65 kv 8 ma half wave, but I'm planning on going at 40 kv. I included the pictures of the tear down and assembly of my transformer. Now I'm getting ready for another run (I, very stupidly, tripped on a wire and knocked my neutron detector down. It didn't break, but the bnc connector on top of it did, so I'm fixing it now), and I'll post the results soon.

Re: Neutron Club Application- Zan Chaudhry

Posted: Sat Jul 30, 2016 2:48 am
by Richard Hull
Keep at it and you will get there. The need for an un-impeachable neutron counter is more important than the fusor, itself when claiming fusion. To detect fusion your tube needs a moderator. The tube should be able to be removed. Counts made with and without the moderator are key to proof of fusion.

Richard Hull

Re: Neutron Club Application- Zan Chaudhry

Posted: Mon Aug 01, 2016 5:30 pm
by Zan_Chaudhry
Okay, I'm getting really frustrated now. In order to fix the BNC connector on my 3He tube, I had to change the wires inside because they broke as well. As soon as I did that, all of my calibration is thrown off and I've been trying for hours, but I think my Uranium ore is not what it was advertised to be, meaning my earlier calibration was screwed up as well. So now I have to work with the Cesium at the hospital, but the people at nuclear medicine won't let me stay there for too long. So instead, I thought of buying my own 10 microcuries of Cs-137 from United Nuclear (I had gone there in the past by accident while researching Polonium), but there's still no guarantee that I can get my system working. So now my plan is to buy a BTI bubble detector and use that for now, while at the same time trying to calibrate my 3He detector with the limited time I can get at the hospital (I'll go multiple times though). Now, Mr. Hull, I really appreciate your statement about how tricky it is to calibrate these detectors.

Re: Neutron Club Application- Zan Chaudhry

Posted: Mon Aug 01, 2016 5:50 pm
by Tom McCarthy
Zan, it might be an idea to think about making a trip to someone who has a calibrated source or two/can help out with getting your tube working rather than spending yonks fiddling with it. There's sure to be someone with a calibrated source/tubes etc that will get you working in no time.

Check out if there are any fusioneers in the area willing to help. I see Maryland is in the vicinity of Richmond on a map. Perhaps Richard knows some people who can help if you give him a shout.

Tom

Re: Neutron Club Application- Zan Chaudhry

Posted: Tue Aug 02, 2016 4:46 pm
by Zan_Chaudhry
Okay, thank you for the suggestion. Does anybody know of someone with a calibrated source in the vicinity of Ellicott City, Maryland?

Re: Neutron Club Application- Zan Chaudhry

Posted: Thu Aug 04, 2016 11:38 pm
by Nick Peskosky
You might want to reach out to Timothy Koeth at UMD. He works in the accelerator/experimental reactor department as a professor and would likely be able to lend you a hand. I know he has given tours to many of the younger board members who have ventured his way and loves anything nuclear related.

Re: Neutron Club Application- Zan Chaudhry

Posted: Fri Aug 05, 2016 12:25 am
by Richard Hull
Dr. Timothy Koeth
Associate Research Professor
Director, Nuclear Reactor and Radiation Facilities
Institute for Research in Electronics and Applied Physics
University of Maryland
301-405-4952 (office)


Tim is a good guy and he might find time to help you out. Your tube might work out OK but it is a crap shoot on whether it can be brought to reliable neutron service free of all gamma detection. Again the real test is put the tube, naked in a fast neutron field, take a one minute count, then jam it into a good moderator and count for another minute. The two counts need to be vastly different if it is counting neutrons.

Richrd Hull

Re: Neutron Club Application- Zan Chaudhry

Posted: Fri Aug 05, 2016 10:32 am
by Zan_Chaudhry
Thank you very much for the information.

I'll give him a call and see if he has time, and if he does I'll see what we can do. Hopefully I can get my tube working, but I'm still going to get a bubble dosimeter (If anyone wants to group purchase with me: viewtopic.php?f=13&t=10962). If my detector works properly, then I'll use the dosimeter for getting an isotropic emission rate conversion factor.

Thank you again very much, this is very helpful.

Zan

Re: Neutron Club Application- Zan Chaudhry

Posted: Mon Sep 19, 2016 6:27 pm
by Zan_Chaudhry
Okay, so a lot has happened. My small x ray transformer turned out to have half a burnt secondary that was kind of intermittently working. So I replaced it. My dad happened to have a broken AMX 4 x ray that I opened and removed the transformer from. It's rated at 120 kv 25 ma and it's pretty big. So I fixed it up to my system and built a new probe out of around 180 2.2 m ohm resistors inside a vinyl tube filled with oil and a 400k ohm resistor on the end. I finished all of this yesterday, and I decided to just try it out. I recently got a usb oscilloscope, and I plugged the probe from the scope to my probe. So I fired it up just to take it for a spin, and I got it working at around 2 microns, 32kv and 30ma and I got some neutrons in my bubble detector. I attached the pictures of my new setup, new transformer, and the bubbles, but I didn't really have the cameras set up for watching my grid. I'll repeat today and post the pictures of that. I counted 3 bubbles.

Re: Neutron Club Application- Zan Chaudhry

Posted: Mon Sep 19, 2016 11:42 pm
by Richard Hull
Remember the key to it all related to neutron counts! You need make two equal timed readings....One with tube in moderator and then the tube out of moderator. Voltages and currents have to be proper for the count noted. 16 kv will not do much detectable fusion.

Richard Hull

Re: Neutron Club Application- Zan Chaudhry

Posted: Tue Sep 20, 2016 5:49 am
by Zan_Chaudhry
But wait. I was not using the tube on this test. I was using a bubble dosimeter. And I also wasn't using 16kv, I was using 32.

Re: Neutron Club Application- Zan Chaudhry

Posted: Tue Sep 20, 2016 1:00 pm
by Kuba Anglin
Your results look promising, but I would recommend organizing your data for clarity's sake.

Voltage:
Current:
Deuterium pressure:
Bubble dosimeter sensitivity:
Bubble dosimeter distance from ideal neutron source:
Bubbles generated:
Combined duration of testing:

Also, you should include a photo of the fusion plasma in your report. I would recommend trying to calculate your isotropic neutron emission rate. You said that you intend to operate your fusor soon. Keep all values as consistent as possible and document everything you can. Your evidence should be able to prove fusion beyond a reasonable doubt.

-Kuba

Re: Neutron Club Application- Zan Chaudhry

Posted: Tue Sep 20, 2016 1:35 pm
by Richard Hull
Kuba is correct. Good data presentation in an orderly fashion is a must. Those of us how have done fusion....know fusion in a way that allows critical review. Critical review demands organized, critical and precise data collection and reporting and not a scatter of numbers blasted out on a page.

With a flawless operational 3He counter the ultimate test is the two count method. One count with the tube in moderator and another with the tube outside the moderator.

The 2 micron level is unbelievably low for a D2 pressure, but experience shows that at the rather high voltage and current you claim, minimal fusion is possible. I find it amazing that you attained a glow at those levels.

Try a good report and fill in these blanks

operational data:

1. period of operation from zero counts or zero bubbles to final count or final bubble talley.
2. average voltage of operation over above time span.
3. average current of operation over time span.
4. average deuterium pressure over time span
5. image of fusor grid taken during the run.
6. if using a counter. 1. 10 minute total background count 2. count with tube in moderator over a stated operational time and 3. another count with tube out of the moderator during operation over same period as #2 count.
7. images of the bubble dosimeter before and after count if such a device is used.

Overall, you have shown most of this over a vast number of postings. Try and do all of this in one single polished report posting.

Note data accumulated over 8 runs is not allowed. fitful starts and stops are not allowed. A single run may not be stable but should be continuous. It is from a single run that the data should be submitted. Do not submit a photo from a pretty photo run and voltage and current data from another run, pressure from another or a total bubble count from three consecutive runs.

For us, you must show that a normal run of your fusor has a good average voltage of X and a current of Y and a pressure of Z and a bubble count and all data taken of a single time period of T.

All fo this is spelled out in a FAQ on how to report for inclusion in claiming fusion.

viewtopic.php?f=24&t=3134&p=12644#p12644

Thanks

Richard Hull

Re: Neutron Club Application- Zan Chaudhry

Posted: Tue Sep 20, 2016 3:51 pm
by Kuba Anglin
The anomalous pressure reading is due to inaccuracies in your equipment. Like you, I used a CPS VG200 vacuum gauge for my fusor. After pumping with only the mechanical pump, the gauge read 0 microns. My mech pump is rated at an ultimate pressure of 12 microns. When that gauge reads 0 microns, the real pressure is likely around 15 microns. If you want an accurate pressure measurement, get a proper tc or ion gauge. The CPS gauge is meant for automotive work, not fusion reactors. I ended up using the CPS gauge anyway and simply used the generated voltage as a more accurate guide for the pressure in the chamber.

-Kuba