[Halla12_software] BaBar magnet yoke question (two more questions then my last email)

[Zhiwen Zhao]

I will replace the SY01 and regenerate map and geometry
But I see the both Poisson geometry and GEANT geometry use actually same 
size cylinders. It should be fine.

Zhiwen

On 02/10/2011 11:01 AM, Eugene Chudakov wrote:
> Yes, it was a mistake in the geometry.
> I should be something like:
>
> GPARVOL41 'SY01' 210 'SOLE' 0. 0. 0. 0 'TUBE' 3 180.0 182.0 187.2
>
> What happens with overlapped volume like that, is that one of them might
> be skipped
> at the tracking stage. Fortunately, it is a part of the yoke barrel and
> not on the way of useful particles. Sitting behind the coil it also
> would hardly affect the background.
>
> The GEANT geometry contained fine steel plates, close to the drawings of
> the BaBar yoke. However, it is cylindrical - a simplification with
> respect to the
> hexogonal BaBar structure.
> The Poisson geometry contained thicker cylinders - in order to speed up
> the calculations (a coarser mesh is sufficient).
>
> Eugene
>
> On Wed, 9 Feb 2011, Zhiwen Zhao wrote:
>
>> On 02/09/2011 11:30 AM, Eugene Chudakov wrote:
>>>>>> for the cryo of the coil, there's the outer part made of Iron. It's
>>>
>>> The cryo tanks are made from stainless steel, non-magnetic.
>> I didn't know that. I only notice in geometry file, they are same
>> material coded as 210
>>
>> GPARVOL30 'SOLE' 0 'HALL' 0. 0. 0. 0 'TUBE' 3 1. 1. 1.
>> GPARVOL31 'CRYO' 210 'SOLE' 0. 0. 0. 0 'TUBE' 3 142. 177. 192.5
>> GPARVOL32 'CRYV' 221 'CRYO' 0. 0. 0. 0 'TUBE' 3 147. 172. 187.5
>> GPARVOL33 'SCL1' 209 'CRYV' 0. 0. 0. 0 'TUBE' 3 152. 154. 175.0
>>>
>>>> Eugene answered this. one of them is commented out in am file, I will
>>>> correct it in geometry file.
>>>
>>> What was there in the geometry file?
>> SY02 was not comment out
>>
>> C -- BaBar barrel yoke simplified
>> C
>> GPARVOL41 'SY01' 210 'SOLE' 0. 0. 0. 0 'TUBE' 3 180.0 186.0 187.2
>> GPARVOL42 'SY02' 210 'SOLE' 0. 0. 0. 0 'TUBE' 3 185.2 189.0 187.2
>> GPARVOL43 'SY03' 210 'SOLE' 0. 0. 0. 0 'TUBE' 3 195.6 199.6 187.2
>> GPARVOL44 'SY04' 210 'SOLE' 0. 0. 0. 0 'TUBE' 3 206.0 210.0 187.2
>> GPARVOL45 'SY05' 210 'SOLE' 0. 0. 0. 0 'TUBE' 3 216.4 220.4 187.2
>> GPARVOL46 'SY06' 210 'SOLE' 0. 0. 0. 0 'TUBE' 3 226.8 230.8 187.2
>> GPARVOL47 'SY07' 210 'SOLE' 0. 0. 0. 0 'TUBE' 3 237.0 246.0 187.2
>> GPARVOL48 'SY08' 210 'SOLE' 0. 0. 0. 0 'TUBE' 3 255.6 264.6 187.2
>> GPARVOL49 'SY09' 210 'SOLE' 0. 0. 0. 0 'TUBE' 3 275.0 290.0 187.2
>>
>>>
>>> Eugene
>>>
>>>
>>> On Wed, 9 Feb 2011, Zhiwen Zhao wrote:
>>>
>>>> On 02/09/2011 10:30 AM, Paul E. Reimer wrote:
>>>>> Hello Zhiwen,
>>>>>
>>>>>> 1.
>>>>>> I notice the there is a overllap between two parts of yoke just
>>>>>> around
>>>>>> the coil, as you can see from the lines of the am file
>>>>> I'll have to look at this in more detail
>>>> Eugene answered this. one of them is commented out in am file, I will
>>>> correct it in geometry file.
>>>>>>
>>>>>> 2.
>>>>>> for the cryo of the coil, there's the outer part made of Iron. It's
>>>>>> not included in AM file. But I think it should because it will affect
>>>>>> the field. Or is there other reasons to exclude it?
>>>>> I don't know what the material is.
>>>> shape materiel inner outer half length
>>>> Tube Iron 142. 177. 192.5
>>>> Tube Air 147. 172. 187.5
>>>> Tube Al 152. 154. 175.0
>>>>>> 3.
>>>>>> Both PVDIS and SIDIS used Babar magnets in their first version of
>>>>>> proposal, then used CDF in the second version. Why is the change?
>>>>>> Maybe the reason was made clearer before I join in?
>>>>> In fact, I was under the impression that Babar was used for the
>>>>> acceptance of both detectors, while CDF was used for the engineering
>>>>> report. This was because we had engineering reports and access to the
>>>>> CDF magnet at Argonne and our engineer's worked on this. At the
>>>>> proposal stage, since we were just dealing with a concept, that seemed
>>>>> to work.
>>>> refer to Xin's reply
>>>>>> 4.
>>>>>> in SIDIS second version proposal, CDF yoke design was very similar to
>>>>>> Babar design, only longer. What's the reason you design CDF yoke very
>>>>>> differently now, Paul?
>>>>> I spent more time looking at the field shape this time. In particular,
>>>>> I tried to obtain the same footprint for the detector area with
>>>>> minimal
>>>>> magnetic field in that area. In reality, the question goes back to the
>>>>> detector designers--how much space to you need? The other thing that I
>>>>> did on the recent CDF design is to assume that the target is moved
>>>>> forward in the magnet.
>>>> Besides the two end cups, the middle part of the yoke are different.
>>>> Are those middle part come with magnet so we can't really modify them?
>>>> BaBar design has many more details in the middle part which I think
>>>> Eugene did it not only for field but also engineering concern. Do want
>>>> CDF to take advantage of that?
>>>>>
>>>>> Paul
>>>>>
>>>> Zhiwen
>>>>
>>