Re: wfd (fwd)

[Brendan Kiburg <kiburg@npl.uiuc.edu>]

Dear Peter,
  Perhaps it would also be valuable to include the muSC if the data stream
/data rate permits it.  I would propose including two of the neutron
detectors via the fan out and the muSC/muSCA, at least for some tests to
learn about how our DAQ (in its now working state) handles the rates.

Best regards,

Brendan

On Wed, 30 Nov 2005, Peter Kammel wrote:

> Dear Tim, dear Rob,
> 
> To answer Tim's question:
> 
> We have 15 WFDs running, as we miss a clock for number 16. 
> Ideally we would run 17 WFDs, 16 for all gondolas and
> the last one #17 for
> 3 neutron detectors and the mSCA counter.
> 
> As you see in the email exchange below, we did not risk
> connecting the neutron detectors (they are not read out
> at the moment). However, Dave proposed to run their
> analog signals through a LRS linear fan out, so that their 
> signals are limited to the fan out range. If that's
> acceptable for Rob, we could still try to get some
> neutron detector information during this run, which would
> be extremely valuable.
> 
> Good luck 
> 
> Peter
> 
> -------------------
> Hi Peter,
> I just wanted to confirm my understanding of the wfd channel
> count. You have 4x14=60 channels instrumenting 60 of 64
> gondola channels and need one additional wfd module to complete
> this set-up. Also how many neutron counters are currently installed?
> At present are simple TDC and ADC signals being recorded
> for neutron triggers (and pre-scaled e/g triggers?).
> Cheers, Tim.
> 
> 
> 
> ---------- Forwarded message ----------
> Date: Mon, 28 Nov 2005 14:18:31 -0600 (CST)
> From: Peter Kammel <kammel@one.npl.uiuc.edu>
> To: Robert M Carey <carey@bu.edu>
> Cc: Fred Gray <fegray@socrates.berkeley.edu>,
>      R. Prieels <prieels@fynu.ucl.ac.be>, Peter Winter <peter.winter@psi.ch>,
>      Brendan Kiburg <kiburg@one.npl.uiuc.edu>
> Subject: Re: wfd
> 
> Dear Rob,
> 
> No rush. If it is dangerous, we won't try it during this run and
> rather wait until Rene and Fred's FADCs are ready. BTW Rene, please
> include an input protection like diode clamps, because one never
> can exclude larger signals.
> 
> Thanks for your advice
> 
> Peter
> 
> On Mon, 28 Nov 2005, Robert M Carey wrote:
> 
> > Dear Peter,
> >     Looking at the circuit and the specs for the flash ADC,
> > this looks like a DANGEROUS idea. The problem is
> > that the front end amplifiers will happily drive signals
> > near to their voltage rails but the flash ADC differential
> > inputs have an absolute differential maximum of
> > 2 volts, while the full scale is 0.5 volts. If you want
> > to pursue this idea, I think you should fashion a diode clamp to keep
> > the input signals in the safe range. If you're not in a rush,
> > we can have someone try that here.
> > 
> >                                                                 Rob
> > 
> > Peter Kammel wrote:
> > 
> > >Dear Rob,
> > >
> > >Thus far 15 wfd are running fine, with occasional
> > >glitches. We would need to get another clock
> > >divider from MuLan for the last clock signal.
> > >I will leave this issue to Tim, who will
> > >certainly have a careful look at the wfd
> > >performance. Our extender board is in, and
> > >Genna is ready to make detailed studies
> > >with Tim, once he arrives on Thursday.
> > >
> > >We also are considering to use the wfd
> > >with our neutron detectors. The dynamic range
> > >of the neutron detectors would be set to 3.5-4 MeV.
> > >However, there would also be 10 times higher signals
> > >coming from Michel electrons running straight
> > >through the neutron detector.
> > >Is this dangerous for the wfd? We won't try that
> > >before getting your advice and ok on this issue.
> > >
> > >Many thanks
> > >
> > >Peter
> > >
> > >  
> > >
> > 
> 
> 
>