Tube tech is simple. The beam is combination of Bremsstrahlung X-Rays from the electron beam stopping on the target and XRF from the tungsten (or other target) caused by the electron stream. Same Ka and Kb and La and Lb as we use. Notice in my tungsten target tube, the W La and Lb are filtered out internally and on purpose.

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With Bremstrahhlung, the emitted energy starts at zero and goes up to the highest accelerating Voltage appled, but the bulf of the generated energy will be at 1/3 of that peak V.

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Geo

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From: "taray singh via groups.io" <sukhjez@...>
To: [email protected]
Sent: Friday, February 12, 2021 9:08:06 AM
Subject: Re: [XRF] Xrf coffee ground

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Geo

Unlike Am241,I am not familiar with the X-ray xrf??spectrum yet

Yes I will stack if I have to go beyond 3 secs to cool off.

Regarding Br ,it is coming ?likely?from the coffee

The clear??colorless thin kitchen wrap??is not contributing??to??bromine

Anything with Br will probably??have a??darker shade in my opinion?

Yes I will??keep a file

My ALARA is inverse square law

Get out of the room??and use remote control??to trigger X-ray at a safe distance?

There will be ringing sound until completion

Seems to work

Scatter within room will always be there?

Thanks

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On Friday, February 12, 2021, 10:17 PM, GEOelectronics@... wrote:

Thanks for that analysis Taray. We should keep quite about the free vitamins that are unknowingly being included in coffee, they will raise the price!(joke).

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A few real ideas -

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We can see clearly on your scan the internal filtering and physics of the beam. Notice the "hump" on? the right right side above 20 keV.?

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Scan the kitchen wrap alone to establish baseline. Maybe a compressed ball of it. Keep that file, it can be subtracted from scans of actual samples

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Think about "stacking". This is when the beam needs to be cooled off between scans or the scan needs to be interrupted. Pause the Si-PIN from counting until the beam is ready again, then start it up and apply beam. If the setup is unchanged, the peaks of interest will stack up on top of the previous ones.

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ALARA-

Geo

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From: "taray singh via groups.io" <sukhjez@...>
To: [email protected]
Sent: Friday, February 12, 2021 4:04:13 AM
Subject: Re: [XRF] Xrf coffee ground

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Hi guys
No analysis is complete without a control
Here is an xrf of the? same fresh coffee beans (partly crushed to make it more homogenous)
Wrapped in a thin kitchen plastic sheet.
In line with the higher count rate,peaking time? increased to 32.
Xray exposure 3 secs
?This time peaks are seen more clearly
This is partly due to the hot water scavenging effect? of the coffee beans? by the coffee maker? releasing ingredients into the cup.
This time peaks noted are Fe,Ni ,Br and Rb plus Pb
Pb is probably due to residual contamination?
Rb is obvious this time
Brazilian coffee is well known for this.
Mine is Vietnamese
Bromine is something unexpected
.It?could be? due to bromine pesticides used in the plantation.
Looks like I? cannot find any faults in Nescafe Milano? coffee maker used in my office
But I will not drink the coffee
Coffee fresh? mca attached.
Taray

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