The past few days I’ve been working on indium activation with my Fusor. To do so, I assembled the following:
6x6” paraffin moderator cut in half
1.5x1.5” sq indium foil
LND7311 pancake at 900v
Nucleus 500 digital scaler
The indium foil was placed between the two 3” paraffin halves and placed 8cm from the Fusor. This would place the indium approx 16cm away as it was in the center of the two paraffin halves (see pic).
-Pre activation background-
The LND7311 registered 359 normal background counts in 10 minutes which equates to 35.9cpm. I conducted the same background assessment two other times which resulted in a ~5cpm difference.
-The run-
The Fusor run consisted of:
5 minutes
43kV
3mA
40mTorr D2 pressure
3.45e5 isotropic n/s
6.91e5 fusions/s
After the run was completed and with the fusor input voltage switched off, the LND7311 pancake registered the following numbers:
Timed 1 minute counts:
1. 103cpm
2. 69cpm
3. 64cpm
4. 60cpm
5. 56cpm
It seemed to stagnate around 50-60cpm but slowly decayed to 40cpm after 1 hour.
Here’s a YT video of the first 2 minutes.
https://youtu.be/3J3jUPI_FPw
Any comments, criticisms, etc welcomed.
Mark Rowley
First attempt at activating Indium
- Mark Rowley
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- Richard Hull
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Re: First attempt at activating Indium
Great work! This is classic activation and only real thermal neutrons can do this. No real-time fallible electronic detection needed. Post bombardment proof that neutrons were produced.
It is a pity that most first pass efforts at fusion rarely make enough neutrons to produce enough activation outside of questionable statistics. it takes a bit of running of a fusor and learning how to handle it to get the numbers needed to make activation a fete accompli
Richard Hull
It is a pity that most first pass efforts at fusion rarely make enough neutrons to produce enough activation outside of questionable statistics. it takes a bit of running of a fusor and learning how to handle it to get the numbers needed to make activation a fete accompli
Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
Re: First attempt at activating Indium
Nice work Mark.
Here is my first gamma spec measurement.
- Indium Foil (100x100x0.1mm) sandwiched with 100x100x50mm LDPE blocks.
- 120sec exposure
- 1in^2 NaI Detector, 900V, 1000sec count
Here is my first gamma spec measurement.
- Indium Foil (100x100x0.1mm) sandwiched with 100x100x50mm LDPE blocks.
- 120sec exposure
- 1in^2 NaI Detector, 900V, 1000sec count
- Mark Rowley
- Posts: 909
- Joined: Sun Dec 29, 2002 12:20 am
- Real name: Mark Rowley
- Location: Sacramento California
- Contact:
Re: First attempt at activating Indium
Thanks Joe.
My gamma spec arrangement is currently in the house but I hope to get another setup in the workshop sometime soon. Capturing telltale photopeaks from activation work would be most interesting and has been on the to-do list for awhile now.
Mark Rowley
My gamma spec arrangement is currently in the house but I hope to get another setup in the workshop sometime soon. Capturing telltale photopeaks from activation work would be most interesting and has been on the to-do list for awhile now.
Mark Rowley
- Richard Hull
- Moderator
- Posts: 14991
- Joined: Fri Jun 15, 2001 9:44 am
- Real name: Richard Hull
Re: First attempt at activating Indium
Great work! Activation is a lot of fun and is one of the key benefits, for me at least, in having a fusor in the first place.
Richard Hull
Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
- Jim Kovalchick
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- Joined: Wed Apr 13, 2011 8:00 pm
- Real name:
Re: First attempt at activating Indium
Nice work Mark! When I read that you used big blocks of parafin, I was reminded of a historic treasure I recently visited in Munich. At the Deutsches Museum, they exhibit Otto Hahn's lab desk complete with version of Meitner's experiment that first measured fission, complete with a big block of wax. Consider yourself in esteemed company!
Jim K
Jim K