![]() ![]() The experiments can introduce students to the problem of detecting the dark matter thought to dominate the universe and to the techniques used to detect contraband fissionable nuclear materials. Several other experiments using these neutron sources are also feasible. Alternatively, a more sophisticated experiment using liquid scintillators and n / γ pulse-shape discrimination can be performed. The experiment can be performed with conventional nuclear instrumentation and a 1-D multi-channel pulse-height analyzer, available in most advanced teaching laboratories. This includes a fission-neutron time-of-flight experiment using plastic scintillators, which utilizes the prompt γ rays emitted in 252Cf spontaneous fission as a fast timing start signal. We have recently replaced such sources with sealed 252Cf oil-well logging sources (nominal 10–100 μCi), and developed several experiments using them as neutron sources. One microgram of 252Cf produces 2.3 million neutrons per second, an average of 3.7 neutrons per spontaneous ssion.When 252Cf undergoes spontaneous ssion, it produces 140Xe, 108Ru, neutrons and gammas. However, using a Cf-252 source would minimize such liabilities, making the plug back procedure easier with significant savings in time and money.The removal of PuBe and AmBe neutron sources from many university teaching laboratories (due to heightened security issues) has often left a void in teaching various aspects of neutron physics. 252Cf undergoes alpha decay 97 of the time to form 248Cm, and undergoes spontaneous ssion remaining 3 of the time. A lost-in-hole Am-Be source had to be fished, which prevented the operator from plugging the well. This case study demonstrates the value of using a low radiation energy Cf-252 source compared to using high radiation energy Am-Be source when drilling in a depleted reservoir. There is also much closer agreement between the two neutron measurements while wiping out. This is due to the varying formation exposure time experienced by the tool with the Cf-252 source, an invasion effect observed due to the slow rate of penetration (ROP). The data acquired while drilling showed a slight separation between Cf-252 porosity readings and the readings from the tool using an Am-Be. The Cf-252 source tool was placed on the top of all other tools in the BHA in recorded memory mode. The data was compared while wiping in, wiping out, and drilling. This paper presents new experimental results of correlated, prompt neutron emission from the spontaneous fission of252Cf Specifically, we present correlated-neutron emission probabilities and. By running both sources in the same bottomhole assembly (BHA), the quality of the Cf 252 could be validated by comparing the back-to-back measurements generated from both Cf-252 and Am-Be sources. To prove the effectiveness of the new source, it was decided to run the Cf-252 back-to-back with the Am-Be source. Fission neutrons have an energy range of 0 to 13 MeV with a mean value of 2.3 MeV and a most probable value of 1 MeV. Although higher-output Cf-252 sources can be obtained to lengthen the useful life of the source, cost and safety may be issues. Californium-252 (Cf-252, 252 Cf) undergoes spontaneous fission with a branching ratio of 3.09 and is used in small sized neutron sources. However this reduces the useful life of the source to somewhere between 5 and 10 years. The neutron fluence rate at a distance of 50.0 0. This fission reaction has a half-life of 2.6 years compared to 430 years for Am-Be, which means that the neutron output of the source drops by a factor of two every 2.6 years. Expert Answer 1st step All steps Final answer Step 1/2 A. A typical Cf-252 source with an activity rating of 20 mCi emits about 108 n/s compared to 16 CI from Am-Be. One gram of Cf-252 yields about 1,012 neutrons per second (n/s), which is a much higher neutron yield than Am-Be sources. The Cf-252 sources emit neutrons as a result of spontaneous fission with a probability of about 3%. With the much shorter half-life time Cf-252 neutron source, ADCO could minimize the associated liability of getting stuck downhole by eliminating the use of high energy radioactive sources with 430 year half-lives. In depleted carbonate reservoirs, the low radiation energy, short half-life Californium-252 (Cf-252) neutron source provides a "fit for purpose" replacement to the high radiation energy, long half-life americium-beryllium (Am-Be) neutron source. UAE environmental regulations call for minimizing exposure to radioactive waste while drilling. ![]()
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