Re: list of assignments for bcal decision

[Elton Smith <elton@jlab.org>]

HI George,

See below:


On Wed, 11 Apr 2007, George Lolos wrote:

> Hi Elton:
>
> A couple of comments with regards to your e-mail below:
>
> 1. The review (teleconference I presume) next Monday is a good idea and
> we will participate from Regina.

We are planning for 1:00 pm on Monday.

To connect by telephone:

1.) dial:
 800-377-8846 : US
 888-276-7715 : Canada
 302-709-8424 : International

2.) enter participant code: 39527048#  (remember the "#")

>
> 2. I thought that the meeting on the 23rd is not to make any decision
> regarding the BCAL read-out, but instead we will discuss in great
> technical details the various options (SiPM's, Planacons and mesh
> PMT's).  Yet you refer to a decision that gets my blood flowing.
> Anything changed or it was a Freudian slip? :-)
>
What we present at the Lehman review this June and how this is presented
must definitely be decided. We are already turning in budget estimates
based on assumptions of the readout, and we need to be able to back them
up with quantitative arguments.

In addition need to satisfy one of our internal milestones for FY07 which
is a "decision on the readout for the barrel calorimeter." This was
presented at the last Lehman review and is also shown as slide #6 in the
manpower and budget presentation that Elke showed the collaboration less
than two weeks ago (see /group/halld/INFO-FOR-COLLAB/Budget_manpower.ppt)

Also, the deadline for the following Recommendation #27 IPR (2005) Sec 2.5
is June 2007:

"Develop a plan for readout of GlueX barrel calorimeter based upon
conventional photomultiplier tubes.  The plan should include fiber
routing, end iron configuration, shielding, and cost estimate."

So, yes, decisions need to be made. Are they final? No, but the longer we
wait the harder they are to change, and we must make our best effort to
make the best and most informed decisions possible.

> 3. I have received notification from SensL that a couple of their people
> will be able to visit JLab next week and perhaps be able to take part in
> some of the discussions on the April 23-24.  I would strongly encourage
> this possibility to hear from the source directly the update and be able
> to ask all the specific questions we need.  This partly addresses your
> suggestion of persons outside the project.  What other names do you have
> in mind and what is their role or expertise?  Meetings that have too
> many persons involved get cumbersome and not as productive as smaller
> groups of persons directly in the know.  On the other hand, we don't
> want to exclude anyone with specific knowledge on field resistant
> sensors and electronics expertise.  Please, don't invite Domingo and
> others just for an audience and ideas on the fly.
>
We have not heard anything about anyone from SensL visiting JLab, and we
want to make sure that their time he is productive. So they should let us
their schedule ASAP. Depending on who is coming and their expertise
(technical? sales?), it may or not be appropriate for them to participate
in our discussions.

One of the single most important numbers we need from them (an informal
budgetary estimate is fine, but needs to written down) is the cost per
channel of SiPMs in production (including all auxiliary
mounting/electronics/etc that would be necessary for a particular
configuration).

> 4. Before Zisis and George commit themselves to yet another document,
> please have a look at 739, 708 and 664 (all by Zisis) and see if the
> info is not already there.  I am also working on a detailed report
> showing BCAL response to photons, spectra and read-out segmentation and
> how it matches the SiPM parameters.  Manpower at the UofR is so tight
> now, any duplication of effort on material already readily available
> will only make things worse on other fronts.
>
I hear you. I will try to collect together the necessary info.

> The topics you listed look fine to me.
>
> So sprach Georg
>
> George
>
>
>
> >>> Elton Smith <elton@jlab.org> 04/11/07 6:04 AM >>>
>
> Hi Bcal enthusiasts,
>
> I would like to reserve an hour on Monday afternoon (I suggest 1:00 pm)
> to
> review issues that need addressing before the Bcal decision meeting the
> following week. Below is a list of issues that need updates. I have put
> some names down on the likely candidates for reporting on these.
>
> It might also be useful to go over the format/schedule for the Bcal
> review
> (times, format, etc). Do we want to ask a couple of persons which are
> not
> direcly in the project to give us some feedback?
>
> I would also ask George/Zisis to prepare a 1-2 page table of Bcal design
> parameters in a format similar to what was done for the drift chambers
> before the DC review (See for example GlueX-doc-740). We will need this
> for all subsystems in preparation for CD-2, so this is a good time to
> create it for the Bcal. (This information is in various documents and it
> will be useful to summarize it into a couple of pages).
>
> Topics (please send me items that are missing)
>
> 0.  How to summarize how physics needs drive the design specs
>         - energy resolution
>         - energy threshold
>
> 1.  SiPM
> 	- linearity/dynamic range
> 	  - need for amplification
> 	- need for cooling?
>           - measurements of dark rate (Carl)
>           - spectrum of dark noise (Carl)
> 	- lifetime (DESY experience) (George)
>         - outline of single electronics channel (LV/disc/signal/etc)
>           (George/Zisis)
> 	- budgetary estimate from SensL
>
> 2.  Planacon
> 	- amplifier/shaper (Carl/Vladimir?)
> 	- light guide design / optics of light collection of WC into
>           fibers (George?)
> 	- placement
>           - B-field map of fringe field (David)
> 	- lifetime
>         - measurements of dark rate (Carl)
>
> 3.  Wire Mesh
>         - use in combination with SiPMs?
>
> --
>
>