Re: [BLAST_ANAWARE] # of kC for projected blast results

From: John Calarco (jrc@einstein.unh.edu)
Date: Tue Jul 20 2004 - 10:19:41 EDT


Tancredi, et al.,

   Let me ask a question to clarify some confusion I have. Is everyone
giving projections for a TOTAL of 300 kC or for 300 kC IN ADDITION to
what we have?

                                                             John

On Thu, 15 Jul 2004, Tancredi Botto wrote:

>
> Hello,
> at the last meeting (the minutes are still in my crashed HD..) we agree
> on using a uniform scaling factor to be applied to projection of future
> data.
>
> We also agreed that one should assume the current target thickness and
> polarization "as is". This eliminates 40,60 cm, M=2, M=4,.. discussions.
> As a benchmark I then take last week's running, when we integrated 23.6 kC
> over 7 days, and 16 shifts (I take out 5 shifts lost due to power failure
> recovery). That makes it 1.5 kC/shift.
>
> So <on average> we should be able to integrate 25.5 kC/week. Counting for
> another 13 weeks, that should add up to be about 330 kC. This corresponds
> to 1000 continuous hrs with a flat 91.2 mA current. So please scale your
> statistics (at the current yield, polarization) to 300 kC.
>
>
> The goal is to have that much by october 17 (with no other contingency).
>
> I guessed that during a typical production week we "lose" 4 shifts of ABS
> data due to a) snake-fill b) empty-tgt c) unpol_running, which corresponds
> to an 80% beam-on-pol-target efficiency. Clearly some weeks it may be
> only 3 shifts, some others we may overall loose more time. You can argue
> that the above estimate is a bit conservative but it is a good start.
>
> Note that last week we had injection current was 140-150 mA, lifetime was
> around 25 mins, with dead time of 20 % at 130 mA, 10 % at 90 mA, adding
> another 15 % inefficiency. We mostly re-injected at 90 mA, which was
> optimal.
>
>
>
>
>

-- 
John R. Calarco
Dept. of Physics
Univ. of New Hampshire
Durham, NH 03824
phone: (603)862-2088
FAX:   (603)862-2998
email: calarco@unh.edu



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