Re: [BLAST_ANAWARE] BLAST - calibration, measurements, last minute ideas

From: Michael Kohl (kohlm@MIT.EDU)
Date: Fri Apr 22 2005 - 18:44:38 EDT


Hi Taylan,

is your suggestion to do more field-off running based on insufficient
statistics or data quality of the so far taken field-off runs?
I'm not sure completely, but I think that we have taken some of these runs
with the present configuration, haven't we?
Were really all fields off including the holding field in those runs?

Regards,

   Michael

On Fri, 22 Apr 2005, Taylan Akdogan wrote:

> Hi Doug,
>
> I find neural network (yours and more general methods) approach
> for the event reconstruction intriguing. For -satisfying- future
> curiosity, it would be nice to have -more- Field-Off (Blast AND Holding
> field) data with blast where new approaches can be tested
> -relatively- easily. Field off data reduces the complexity of the
> fitting, by introducing two coupled -left-right- set of information,
> and removing -any- possible higher degree of local uncertainties in
> magnetic field due to materials in the volume and holding field near
> vertex: like pumps on the road.
>
> Off course, this can not be justified just to satisfy a curiosity
> which is not guaranteed to be pursued. If you think any other
> reason for Field-Off data (such as detector alignment) from which
> Blast can benefit, you can also consider it to be a potential
> resource for new analysis techniques. Something to think about...
>
> Taylan
>
> --
> ---=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=---
> Taylan Akdogan Massachusetts Institute of Technology
> akdogan@mit.edu Department of Physics
> Phn:+1-617-258-0801 Laboratory for Nuclear Science
> Fax:+1-617-258-5440 Room 26-559
> ---=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=---
>
> On Apr 22, 2005, at 2:46 PM, Douglas Hasell wrote:
>
> > Dear Colleagues,
> >
> > As you are hopefully aware BLAST will run until May 31. After that
> > there will be approximately 1 week for TeraHz studies and then we will
> > make some final calibration measurements. So far these include:
> >
> > - surveying the detector position (primarily the wire chamber but
> > also the sub-detector frame) - 1 week
> > - map the target holding field - <1 week
> > - map the toroidal field - 2 weeks
> >
> > We will try to do enough empty and unpolarised H and D runs before
> > the end of May during the normal running.
> >
> > We will also try to get as many cosmic runs as possible within the
> > TeraHz period, as well as during the survey and holding field
> > measurements, after hours, as possible.
> >
> > But please realise that after the end of May BLAST will start to be
> > disassembled and it will be non-reversible except with great pain and
> > suffering.
> >
> > For the holding field maps the target cell will be removed.
> >
> > For the toroidal field map, after a preliminary set of measurements
> > are made at a small number of points with the wire chambers in place;
> > the wire chambers will be removed. This means all neutron detectors
> > and the lead glass will also be de-cabled and removed. TOF's and
> > Cerenkov's will stay in place but will be de-cabled. BAT's may also
> > need to be de-cabled and possibly removed.
> >
> > So, if there are any other measurements or tests that should be done;
> > please let me know as soon as possible.
> >
> >
> > Cheers,
> >
> > Douglas
> >
> > 26-415 M.I.T.
> > Tel: +1 (617) 258-7199
> > 77 Massachusetts Avenue Fax: +1 (617)
> > 258-5440
> > Cambridge, MA 02139, USA E-mail:
> > hasell@mit.edu
> >
>
>

-- 

+-------------------------------------+--------------------------+ | Office: | Home: | |-------------------------------------|--------------------------| | Dr. Michael Kohl | Michael Kohl | | Laboratory for Nuclear Science | 5 Ibbetson Street | | MIT-Bates Linear Accelerator Center | Somerville, MA 02143 | | Middleton, MA 01949 | U.S.A. | | U.S.A. | | | - - - - - - - - - - - - | - - - - - - - - -| | Email: kohlm@mit.edu | K.Michael.Kohl@gmx.de | | Work: +1-617-253-9207 | Home: +1-617-629-3147 | | Fax: +1-617-253-9599 | Mobile: +1-978-580-4190 | | http://blast.lns.mit.edu | | +-------------------------------------+--------------------------+



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