[time-nuts] Variation in Radioactive Decay Rate with Solar Activity

J. Forster jfor at quikus.com
Wed Aug 3 21:39:52 UTC 2011


You measure the number of counts in a constant time interval. That gives
you a rate, which is predictable from the known half-life of the source.

What you are looking for ius deviations from the rate that correlate wqith
the sun's rotation (or something else).

The best way might be to measure the rate, and then auto-correlate it or
cross-correlate it with, say, the known sun rotation.

-John

===================

> Hi Jim:
>
> The problem I'm having is that just counting the clicks from a source is
> a way to get random numbers.  If you average the clicks over a large
> amount of time and plot that average, it will decrease over time.  So to
> see the change in decay rate the source needs to have a short half-life.
>
> The article mentions (ordered by half life):
> manganese-54 (312.03 days or 26.9E6 sec)
> cesium-137 (30.17 years)
> silicon-32 (170 years or 5.4E9 sec)
> radium-226  (1601 years)
>
> manganese-54 looks like the shortest half life that was mentioned and
> it's avaialble from United Nucular:
> http://unitednuclear.com/index.php?main_page=product_info&cPath=2_5&products_id=819
> Here's their table of Disk Sources which has some isotopes that have a
> shorter half life:
> *Cobalt^57 *270 days
> *Zinc^65 *244 days
> *Polonium^210 * 138 days (also available as a needle source)
>
> So in the disk sources Polonium-210 has the shortest half life.
> http://en.wikipedia.org/wiki/Polonium
>
> ISOTOPE 	ACTIVITY 	HALF-LIFE 	ENERGIES (KeV)
> *Barium^133 * 	1uCi 	10.7 years 	*Gamma: *81.0, 356.0
> *Cadmium^109 * 	1uCi 	453 days 	*Gamma: *88.0
> *Cesium^137 * 	*1*uCi 	30.1 years 	*Gamma: *32, 661.6
> *Beta: *511.6, 1173.2
> *Cesium^137 * 	*5*uCi 	30.1 years 	*Gamma: *32, 661.6
> *Beta: * 511.6, 1173.2
> *Cesium^137 * 	*10*uCi 	30.1 years 	*Gamma: *32, 661.6
> *Beta:* 511.6, 1173.2
> *Cobalt^57 * 	1uCi 	270 days 	*Gamma: *122.1
> *Cobalt^60 * 	1uCi 	5.27 years 	*Gamma: *1173.2, 1332.5
> *Europium^152 * 	1uCi 	13.5 years 	*Gamma: *121.8, 344.3, 1408.0
> *Manganese^54 * 	1uCi 	312 days 	*Gamma: *834.8
> *Sodium^22 * 	1uCi 	2.6 years 	*Gamma: *511.0, 1274.5
> *Strontium^90 * 	0.1uCi 	28.5 years 	*Beta: *546.0
> *Thallium^204 * 	1uCi 	3.78 years 	*Beta: *763.4
> * Polonium^210 * 	0.1uCi 	138 days 	*Alpha: *5304.5
> *Zinc^65 * 	1uCi 	244 days 	*Gamma: *511.0, 1115.5
>
>
> Have Fun,
>
> Brooke Clarke
> http://www.PRC68.com
> http://www.End2PartyGovernment.com/
>
>
> Jim Lux wrote:
>> On 8/3/11 12:14 PM, J. Forster wrote:
>>> Hi Brooke,
>>>
>>> Maybe. The photon counting gear is pretty trivial. You'd need:
>>>
>>> A scintillator
>>> A PMT (Photo Multiplier Tube) and HV stable HV PS.
>>> A preamp
>>> A SCA (Single Channel Analyzer). These can be built.
>>> A counter, stable time base, and data recorder
>>>
>>> The main difficulty, IMO, would be getting a sufficient sized lump of
>>> the
>>> material. Chunks of Cs don't grow on trees, at least not where I live.
>>>
>>
>> Does it have to be Cs?  United Nuclear sells a wide variety of
>> calibration sources for <$100.  Yes, they have Cs137 (10 microCuries)...
>>
>>
>>
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