[G14_run] Fw: [EXTERNAL] Re: Locations of the Kel-F windows

[Tsuneo Kageya]

Privet Igor,

 thank you for the curves
 They are very useful to let our work forward.

      Paka, Tsuneo Kageya.
________________________________
From: Igor Strakovsky <igor at gwu.edu>
Sent: Monday, May 8, 2023 9:59 AM
To: Tsuneo Kageya <kageya at jlab.org>
Cc: g14_run at jlab.org <g14_run at jlab.org>
Subject: Re: [G14_run] Fw: [EXTERNAL] Re: Locations of the Kel-F windows

Dear All,

As a small update....
Andrey and Kirill were ill and now they are back. I will update plots when I will get BnGa recent results

Cheers, Igor


On Mon, May 8, 2023 at 9:54 AM Tsuneo Kageya via G14_run <g14_run at jlab.org<mailto:g14_run at jlab.org>> wrote:
I just forgot to include g14_run to respond to the email from Alessandra the last Friday and am sending it to
everybody.

Ciao Alessandra,

 thank you for the updates.

 I am still reading your email and note.
 I think we may have the following conclusions about empty target subtractions for your case.

(1)  If we are interested only in the range of your z vertex cut of -9.5 < z < -5.8 cm and entrance and exit Kel-F windows' contributions could be
negligible to this z range, the empty target distributions normalized with the downstream Kel-F can be used without complicated
calculations, I think.

(2)  We can use the factors ρrel= 0.7 (in your note) for Gold target (19b) and ρrel= 1.0 for the Silver target (21a) to be multiplied to the empty
distributions for the subtractions.

(3)  Still we may need to shift the z vertex distributions for 21a and 10b target cell positions like you are doing in the note.

 Discussions on the eq. 36 - 38 are for the wider cuts like -10 < z < -2 cm, I think.   Probably you got the ways of calculations from Andy's
 notes.   I used the 0.903 for the subtractions for Gold target with the wider z cut.

 I will try to give you more detailed info. like Al wire's diameter and total number of wires later.

      Ciao, Tsuneo Kageya.
________________________________
From: filippi at to.infn.it<mailto:filippi at to.infn.it> <filippi at to.infn.it<mailto:filippi at to.infn.it>>
Sent: Friday, May 5, 2023 10:22 AM
To: Tsuneo Kageya <kageya at jlab.org<mailto:kageya at jlab.org>>
Cc: alessandra filippi <filippi at to.infn.it<mailto:filippi at to.infn.it>>; g14_run at jlab.org<mailto:g14_run at jlab.org> <g14_run at jlab.org<mailto:g14_run at jlab.org>>; Tsuneo Kageya <kageya at jlab.org<mailto:kageya at jlab.org>>
Subject: [EXTERNAL] Re: Locations of the Kel-F windows

Hi Tsuneo,

>
> Ciao Alessandra,
>
>
>  here is an expanded view of Fig. 28 (attached to this email).
>
>  I would like to suggest to show z range -15 < z < -5 cm for Fig. 28.
>
>  I don't think we need the range of z > -5 cm.

ok, I just put there what I had ready, I can zoom it a little bit.

>
>  We can see the following things from the figure.
>

aaaah, now I understand... the "Aluminum wire" is that sort of messy hank
inside the cell! I believed the wires were tensioned along the walls of
the cylinder. So, they make an overall contribution in the central part
which could potentially be relevant, it makes sense.
We know the density of this wire, has anybody ever weighted the total
amount of Al mass in this region? its length and its cross section, to be
more quantitative?
I'll correct the text accordingly. Sorry my bad, I never understood this
was the real target structure.

>
>  (1) Relative positions of three Kel-F windows for Gold2 (19b) and Empty
> (21a).
>
>  I am attaching the info. about target cell 19b and 21a.
>
>
>  (a) The positions of downstream Kel-F windows for Gold2 and Empty are
> close at Fig. 28.
>
>
>  (b) As can see L1 on the table of the attacment, the difference of 96.21
> - 95.74 = 0.47 mm

ok. Do we care about what happens in the very upstream region, L4?
I assumed not.

>
> is seen at the exit windows at Fig. 28.
>
>
>  (c) L4 difference shown on the table as 36.90 - 34.10 = 2.8 mm can be
> seen at the entrande windows at Fig.28.
>
>

ok

>  (2) Small diffence of downstream Kel-F positions between Silver (21a) and
> Empty (21a) can be observed as 1 mm or so
>
> which could be negligible.
>

yes, I believe the important information is how long is the "HD" volume,
that is l = L1-L3-L4

>
>  In order to understand eq. 35, can you define, l_empty, l_gold, Z
> ^gold_KelF1 and Z^empty_KelF1 ?
>
> What are their equivalent numbers at the table ?

l_{cell} = L1-L3-L3 - they differ for about 1 mm (61.63-59.20 mm), you can
see them in the table. This means that the HD length is slightly different
in the two cases.
Z^whatever_KelF1 is the z I get from a gaussian fit of the entrance window
peak for each cell. I need this and the HD length (see above) to write the
transformation for the z coordinate, to "align" the targets, ie bring the
gold2 entrance window to level up with the empty target entrance. These
are the values reported on the table.
Cheers,
    Alessandra



>
>  Ciao, Tsuneo Kageya.
>
>
>


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