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

Brooke Clarke brooke at pacific.net
Wed Aug 3 21:45:17 UTC 2011


Hi John:

Yes.  I think using the isotope with the shortest half-life will make 
for the most sensitive measurement, nest pas?

Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.End2PartyGovernment.com/


J. Forster wrote:
> 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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>>      
>
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