[Eg2] Target densities

[Steven L. Manly]

Interesting.  Will, you mentioned in today's meeting that someone has a
file with the original measurements?  I didn't catch the name.  Who came
up with the carbon number for the NIM article?

-Steve


> Hi everybody,
>
> After this afternoon meeting I have some concern about the values for the
> target thickness especially Carbon.
>
> In the NIM paper there is a table indicating areal densities as: C = .38 ;
> Fe = 0.31 ; Pb = 0.16 g/cm2
> Simple calculation with Hyupwoo numbers gives 2H = .325 g/cm2
>
> Then ratios of electrons from the targets in data should give something
> around: C = 1.17 ; Fe = .95 ; Pb = .49
> I found with my cuts: C = .91 ; Fe = .96 ; Pb = .46 It is a good agreement
> except for Carbon!
>
> If I use Hyupwoo numbers for the Carbon areal density, I find the same
> than
> in the NIM paper, but I am concerned with the value of 2.267 g/cm3 because
> graphite seem to have variable density depending on the web site you
> consult, what I could grab was that raw mineral graphite is between 2.09
> and
> 2.3 g/cm3 but that once treated it can get much lighter (I seen 1.57, 1.7
> and 1.8 in various places). On the NIST web site they use density of 1.7
> g/cm3 for graphite and that would lead to an areal density of .29 g/cm2
> which give a ratio in data of .90 in agreement with what I observe in
> data.
>
> --
> Raphaël Dupré
>
>
> Argonne National Laboratory
>
> Université Claude Bernard Lyon 1
> _______________________________________________
> Eg2 mailing list
> Eg2 at jlab.org
> https://mailman.jlab.org/mailman/listinfo/eg2