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

[Zhiwen Zhao]

Hi, Paul,Eugene,Xin

Four questions

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

==================================================
&reg mat=	2	&            	; 	6
&po y=	-187.2	,x=	180	&
&po y=	187.2	,x=	180	&
&po y=	187.2	,x=	186	&
&po y=	-187.2	,x=	186	&
&po y=	-187.2	,x=	180	&

;&reg mat=	2	&            	; 	4
;&po y=	-187.2	,x=	185.2	&
;&po y=	187.2	,x=	185.2	&
;&po y=	187.2	,x=	189.2	&
;&po y=	-187.2	,x=	189.2	&
;&po y=	-187.2	,x=	185.2	&
===================================================
Then I notice it's the same in Eugene's geometry input file for comgeant
So I just want to confirm with you guys before I correct it.

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?

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?

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?

Thanks

Zhiwen