From ryu@rcf.rhic.bnl.gov Wed Nov  7 13:34:49 MST 2001
Received: from mailrelay3.lanl.gov (mailrelay3.lanl.gov [128.165.3.1])
	by p2hp4.lanl.gov (8.9.3 (PHNE_22672)/8.8.6) with ESMTP id NAA23548;
	Wed, 7 Nov 2001 13:34:47 -0700 (MST)
Received: from mailproxy1.lanl.gov (localhost.localdomain [127.0.0.1])
	by mailrelay3.lanl.gov (8.11.6/8.11.6/(ccn-5)) with ESMTP id fA7KYsj06995;
	Wed, 7 Nov 2001 13:34:54 -0700
Received: from smtpgw.bnl.gov (smtpgw.bnl.gov [130.199.3.16])
	by mailproxy1.lanl.gov (8.11.6/8.11.6/(ccn-5)) with ESMTP id fA7KYsj19954;
	Wed, 7 Nov 2001 13:34:54 -0700
Received: from bnl.gov ([130.199.128.163])
	by smtpgw.bnl.gov with esmtp (Exim 3.32 #1 )
	id 161ZPO-0000f9-00; Wed, 07 Nov 2001 15:34:50 -0500
Received: from rcf2.rhic.bnl.gov (root@rcf2.rhic.bnl.gov [130.199.6.81])
	by bnl.gov (8.9.2/8.9.2) with ESMTP id PAA13896;
	Wed, 7 Nov 2001 15:34:49 -0500 (EST)
Received: from rcf2 (rcf2 [130.199.6.81])
	by rcf2.rhic.bnl.gov (8.9.3+Sun/8.9.3) with ESMTP id PAA27168;
	Wed, 7 Nov 2001 15:34:47 -0500 (EST)
Date: Wed, 7 Nov 2001 15:34:47 -0500 (EST)
From: Sangsu Ryu <ryu@rcf.rhic.bnl.gov>
X-X-Sender:  <ryu@rcf2.rhic.bnl.gov>
To: britton <brittoncl@ornl.gov>
cc: "John P. Sullivan" <sullivan@rcf2.rhic.bnl.gov>, <younggr@ornl.gov>,
        "Glenn R. Young" <younggr@earthlink.net>,
        Hubert van Hecke <hubert@p2hp4.lanl.gov>, <young@mail.phy.ornl.gov>,
        <aghansen@rcf.rhic.bnl.gov>, <leitch@lanl.gov>, <plm@lanl.gov>,
        <mischke@lanl.gov>, <jhkang@phya.yonsei.ac.kr>,
        <sullivan@rcf.rhic.bnl.gov>, <shiina@p2hp4.lanl.gov>,
        <bobrek@files.ic.ornl.gov>
Subject: Re: mvd noise versus kapton cable length (fwd)
In-Reply-To: <5.1.0.14.2.20011030114720.00a9da90@files.ic.ornl.gov>
Message-ID: <Pine.GSO.4.33.0111071523170.16611-100000@rcf2.rhic.bnl.gov>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
Status: RO

Dear all,

	I made an Mvd noise distribution map at
http://www.phenix.bnl.gov/~ryu/public/mvd/noise.html

Take look at the first plot. X is pannel number along Z (phenix coordinate
system) and Y is row number. Bigger box means the packet is noisier. The
other plots in the page are to explain distribution along Y axis. What I
am wondering about is how we can explain distribution along X axis.
Aparrently north side is much noisier than south. I cannot find any
assymetry in Mvd geometry (or whatever) which can make noise distribution
this assymetrical.

Best regards,
Sangsu


On Tue, 30 Oct 2001, britton wrote:

> Excellent....
>
>
>
> At 11:08 AM 10/30/2001 -0500, John P. Sullivan wrote:
> >Hi,
> >    I do not have the schematic, but I'll see what I can produce.
> >I do have this note from Toshi, which says the shields are connected
> >to the "bias return" -- which is +5V analog, not ground.
> >
> >---------------------------------------------------------
> >
> >This is what I asked Toshi:
> >
> > > Hi Toshi,
> > >     I know that bias return is tied to +5V analog on the Silicon detectors.
> > > I assume that the shield on the back of the kapton cables is tied to
> > bias return.
> > > Is that true?
> > > Thanks,
> > > John
> > >
> >
> >----------------------------------------------------------
> >
> >And here is his reply:
> >
> >yes, John, that's true.  Two bias return lines are connected to the
> >backing shield by via holes.
> >Toshi 17:15MST Monday 10/29/01
> >
> >PS. There are two 0.047uF capacitors between bias and bias return lines
> >on a kapton cable.
> >
> >----------------------------------------------------------
> >
> >Regards,
> >John
>
> Chuck Britton, Ph.D.
> Oak Ridge National Laboratory
> Bethel Valley Rd., MS6006
> P. O. Box 2008
> Oak Ridge, TN 37831-6006
> _________________________
> email: brittoncl@ornl.gov
> Phone: (865) 574-1878
> FAX:   (865) 576-2813
> WWW: http://www2.ic.ornl.gov/monolithic/brittoncl.htm
>