Thanks, Richard
You are right. I was too naive in my reasoning. What I see is more like
an increase of a factor of 1.5 (or 50%). I think that it means that the
next time the hall is open we should probably adjust the nozzle
possition in an attempt to optimize the flow into the cell.
Vitaliy
Richard Milner wrote:
>Vitaliy,
>This is not quite right. The conductance of the tube and so the central
>density is linear in the length. Ignoring the conductance of the inlet
>tube, then the target thickness should scale as the square of the length.
>Thus, the thickess would increase by (3/2)^2 = 2.25. If you take only +/-
>20 cm instead of the full +/- 30 cm you lose only 0.25 so the increase
>becomes 2.0. Now including the inlet conductance will probably reduce the
>increase to about 1.75 - Hauke knows the correct numbers.
>Richard
>
>On Tue, 4 May 2004, vitaliy ziskin wrote:
>
>
>
>>To resolve a general misconseption. Yes, it is true that 60 cm vertex
>>goes from +/- 30 cm and in fact we see that. However, we CANNOT use
>>extra 20 cm at the edges due to a target field change of sign. So we
>>still work with a target of +/- 20 cm. The only gain is due to a
>>conductace change which is linear with the length and thus should go up
>>by a factor of 60/40=3/2 which is what, I think, we see. I would like
>>elastic people :-) verify what I see.
>>
>>
>> Cheers, Vitaliy
>>
>>Manouch Farkhondeh wrote:
>>
>>
>>
>>>Vitaly:
>>>
>>>Why is that the vertex reconstructed for 60 cm (red) goes to 0 near
>>>+/-20 cm? instead of +/-30 cm, and is very much similar to the 40 cm
>>>target? I thought this morning in the counting bay I saw the on line Z-
>>>distribution vanishing at +/-30.
>>>Manouchehr
>>>
>>>vitaliy ziskin wrote:
>>>
>>>
>>>
>>>
>>>>I include the vertex reconstructed for 60 cm cell (red) and 40 cm cell
>>>>(black) normalized to charge. I seems that we are only gaining 25% not
>>>>a factor of 2. What has changed? Are the cerenkov efficiecies still
>>>>the same? Should we adjust the nozzle to maximize the gas flow into the
>>>>cell? Is the reconstruction efficiency the same?
>>>>
>>>> Cheers,
>>>>Vitaliy
>>>>
>>>> ------------------------------------------------------------------------
>>>>[Image]
>>>>
>>>>
>>>>
>>>>
>>>
>>>
>>>
>>>
>
>
>
This archive was generated by hypermail 2.1.2 : Mon Feb 24 2014 - 14:07:31 EST