Search found 128 matches

by Bruce Meagher
Fri Jan 11, 2019 7:49 am
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Neutron Test Sources Po210+Be or U238+Be?
Replies: 15
Views: 5508

Re: Neutron Test Sources Po210+Be or U238+Be?

Great job trying to answer my questions. The specific activities you found are accurate, and you correctly observed the huge difference. One thing you might not fully understand yet is what the units mean. A becquerel (Bq) is the unit of radioactivity. 1 Bq = one radioactive disintegration (decay) p...
by Bruce Meagher
Wed Jan 09, 2019 3:58 pm
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Neutron Test Sources Po210+Be or U238+Be?
Replies: 15
Views: 5508

Re: Neutron Test Sources Po210+Be or U238+Be?

Yes. Look up the specific activity of U238 and Po210. What does this tell us about the two substances? How much U238 would you need to create 1 million alphas/second? Can you find out approximately how many 4 - 5 MeV alphas/second are needed to create one neutron/second with the type of beryllium yo...
by Bruce Meagher
Mon Jan 07, 2019 8:32 pm
Forum: Vacuum Technology (& FAQs)
Topic: Cleaning/Repairing Edwards E2M5
Replies: 27
Views: 14247

Re: Cleaning/Repairing Edwards E2M5

... I still need to find a proper inlet valve for gauging. I can't find anything so far for a good price. I need it to be a KF flange which is the biggest problem. Any recommendations? You could try <https://www.ebay.com/itm/292158415411> for $12.50 shipped. The image below is what I received. It d...
by Bruce Meagher
Sun Jan 06, 2019 4:56 pm
Forum: Fusor Construction & Operation (& FAQs)
Topic: Creation, usage, and destruction of a cathode
Replies: 12
Views: 4938

Re: Creation, usage, and destruction of a cathode

Great question! but i do not know for sure? my theory is that they would be the same because an X-ray is created by an exelorated electron that collides with a material 'brimsstraholing' and the power supply (voltage and current) is giving the electrons so i think it will be the same for the same V...
by Bruce Meagher
Sun Jan 06, 2019 6:15 am
Forum: Vacuum Technology (& FAQs)
Topic: The Importance of TC Gauge Calibration
Replies: 13
Views: 9069

Re: The Importance of TC Gauge Calibration

Glad the gauge helped. Finn's sweet vacuum controller sure makes it easy for a quick measurement.
by Bruce Meagher
Sun Jan 06, 2019 6:11 am
Forum: Fusor Construction & Operation (& FAQs)
Topic: Creation, usage, and destruction of a cathode
Replies: 12
Views: 4938

Re: Creation, usage, and destruction of a cathode

Enzo, I'd second Richard's warnings about the high voltage. You might consider getting a long (3'+) insulating rod to use as a pointer instead of using your hands. Best to train yourself early to minimize the chance of a mistake in the future. Also for your x-ray experiment what happens when you run...
by Bruce Meagher
Fri Jan 04, 2019 7:45 pm
Forum: Vacuum Technology (& FAQs)
Topic: MKS 901p
Replies: 58
Views: 34383

Re: MKS 901p

Rich, I don’t have any insight into your broken 901p, but can you dump of all the parameters? Cut and paste the following commands into your favorite terminal program when you’re connected to the device. @254PR1?;FF @254PR2?;FF @254PR3?;FF @254PR4?;FF @254BR?;FF @254AD?;FF @254RSD?;FF @254MD?;FF @25...
by Bruce Meagher
Thu Jan 03, 2019 10:56 pm
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: How to figure out the specs of old Rigaku scintillation tube probe?
Replies: 24
Views: 11894

Re: How to figure out the specs of old Rigaku scintillation tube probe?

Harald, It would have helped if you included a picture or a link to the detector you were considering. A quick eBay search turned up a Rigaku scintillator detector such as this <https://www.ebay.com/itm/153324151509>. Is this similar to what you were considering? I’ve included a couple images below ...
by Bruce Meagher
Tue Jan 01, 2019 5:49 pm
Forum: Vacuum Technology (& FAQs)
Topic: The Importance of TC Gauge Calibration
Replies: 13
Views: 9069

Re: The Importance of TC Gauge Calibration

Luke, I have a calibrated MKS 901p you can borrow. PM me your address and I'll send it over. You can use it to check the results against your two other gauges. I also have a similar varian 531 controller as the one pictured above. I have to zero the gauge for each specific 531 TC in order for it to ...
by Bruce Meagher
Sun Dec 30, 2018 8:23 am
Forum: Vacuum Technology (& FAQs)
Topic: Poor performance of old diff pump.
Replies: 13
Views: 9649

Re: Poor performance of old diff pump.

I looked up your roots booster backing pump and it does have a tremendous throughput. From the paper specs when the diffusion pump is at 1e-4 Torr and the foreline is at 5e-3 Torr the throughputs look similar at 2 Torr*liter/sec (assuming your DP is similar to the Varian HS-20). Your realized throug...