[Halld-cal] comments to BCAL calibration (fwd)

[Zisis Papandreou]

Hello Alex:

Excellent!  Thanks and cheers, Zisis...

On Jan 28, 2014, at 2:15 PM, Alexander Somov <somov at jlab.org> wrote:

> 
> Hi Zisis,
> 
> We'll be able to acquire calibration triggers (like cosmic, led)
> concurrently with physics triggers.
> 
> Cheers,
>      Alex
> 
> 
> ---------- Forwarded message ----------
> Date: Tue, 28 Jan 2014 12:39:09 -0500
> From: Elton Smith <elton at jlab.org>
> To: Zisis Papandreou <Zisis at uregina.ca>, Sean Dobbs <s-dobbs at northwestern.edu>,
>    Yi Qiang <yqiang at jlab.org>, "halld-cal at jlab.org" <halld-cal at jlab.org>
> Subject: [Halld-cal] comments to BCAL calibration
> 
> Hi Zisis,
> 
> Here are some belated comments to your document GlueX-doc-2379. I notice
> I made my comments on the version on Dec 17 and there is an updated
> version. In a  cursory glance I did not the changes, but I could be
> providing redundant suggestions.
> 
> 
> General: It is good to have the GlueX-doc number at the top. My hard
> copy lacked this and it took me a while to find where I got the document.
> 
> Th first table (conditions parameters) contains very similar information
> to what may be included in online data bases. These are still under
> discussion, so the two need to be designed together so that they
> complement each other and minimize duplication. For example, the SiPM
> bias voltages will be recorded and monitored by EPICS and I don't know
> how this information will be needed beyond that.
> 
> LED_cntl_clock, LED_cntl_width, LED_bias
> There are a total of 32 independent pulsers (16 upstream, 16
> downstream). Each of 4 pulses are duplicated 12 times and delivered to
> quadrants, up or down.
> I assume the clock is the rate at which the pulser is pulsed.
> 
> These next two are clearly DAQ settings and would be part of the
> configuration files
> ADC_threshold. Is this the same as the pedestal subtracted for the
> trigger? Is it a sparcification threshold?
> TDC_threshold. Is this the discriminator threshold?
> 
> The next will be recorded and monitored by EPICs
> SPM_bias_hv
> SPM_bias_lv. There are a total of 48 independent channels (24 +5V, 24
> -5V). Each channel serves 4 readout assemblies on one side.
> SPM_crate
> N2_flow. At the moment we do not monitor the N2 flow, they are visual
> flow meters. However, we do monitor temp and humidity inside the readout
> assemblies
> 
> This information should be set in a configuration file
> COOLING_temp - I assume this is the set point for the chiller? This
> would be the temperature of the water in the cooling loop
> 
> The following information should be monitored and controlled from EPICS
> SPM_temp - There is one RTD temperature probe on each cooling plate,
> i.e. 96.
> Readout assembly temperature and humidity. There are 8 probes (4
> upstream, 4 downstream) in the air (N2) volume of the readout
> assemblies. They measure temperature and humidity, so the dew point can
> be calculated.
> HALLD_humidity - There is only discussion at the moment to add a probe
> to determine the general conditions of the hall.
> 
> Table 2 (Calibration constants)
> 
> I assume we need an offset and gain for each ADC channel is related to
> the ADC_...._position and width information.   While I agree that there
> may be different methods of determining the gain (cosmics, pulser,
> physics, etc), I think we probably want to store somewhere the "best
> estimate" of the actual gain information for each ADC channel. The
> procedure for determining this value is yet to be determined and may use
> several of the inputs so far mentioned.
> 
> ADC_gain 1536 channels
> ADC_offset: 1536 channels
> ADC_time_offset: 1152 channels
> 
> For the ADC_physics
> What is meant to the ADC_physics_position or TDC_physics_position, etc
> values? The intent is to use pi0 and eta production to extract the
> information. However, these will not yield a single peak, but rather pi0
> peaks will be determined using combination of two showers (each shower
> with multiple ADC channel). From this a  procedure will have to be
> developed to determine the gains of each channel.
> 
> For the TDC_physics_
> What would be used for the source of this information?
> 
> Thanks, Elton.
> 
> 
> -- 
> Elton Smith
> Jefferson Lab MS 12H5
> 12000 Jefferson Ave STE 16
> Newport News, VA 23606
> (757) 269-7625
> (757) 269-6331 fax
> 
> _______________________________________________
> Halld-cal mailing list
> Halld-cal at jlab.org
> https://mailman.jlab.org/mailman/listinfo/halld-cal


Dr. Zisis Papandreou
Professor of Physics, Ph.D, P.Phys.
---------------------------------------------------------
Department of Physics   
University of Regina	    
3737 Wascana Parkway
Regina, SK  S4S 0A2	 CANADA

Phone: (306) 585-5379
Fax: (306) 585-5659
Email:  zisis at uregina.ca
Website: http://kronos.phys.uregina.ca/~zisis/professional/




-------------- next part --------------
An HTML attachment was scrubbed...
URL: https://mailman.jlab.org/pipermail/halld-cal/attachments/20140128/fa812f69/attachment.html