Experimental Physics and
Industrial Control System

Solal <[email protected]> · Thu, 04 Sep 2008 11:20:23 +0200

					Dear Kazuro,

    I have an experience of Bergoz 352 MHz LR-BPM for Linac.

  Our LR-Bergoz processes in track-Continuous mode. The positions are
effectively noisier and instable due to the input logarithmic amplifier. The
position processed is also more instable and noisier at low intensity beam.

  A hard signal triggers an NI-PXI daq card and we have no problem.

  The LR-BPM has a poor resolution to analyse high order beam.

 Please could you ask precise questions?   And I will ask you more
information if I need it to help you.

                                       Maurice C. Solal

                                       Insitute of Nuclear Physics 
						    CNRS
                                       France

-----Message d'origine-----
De : Gougnaud Françoise [mailto:[email protected]] 
Envoyé : mercredi 6 août 2008 10:24
À : Patrick AUSSET; Maurice Solal
Objet : TR: Bergoz LR-BPM Monitoring system for LINAC

Bonjour,
Je vous transmets ce mail du tech-talk EPICS.
Amicalement,
Françoise.
-----Message d'origine-----
De : [email protected] [mailto:[email protected]] De
la part de Kazuro FURUKAWA
Envoyé : mercredi 6 août 2008 00:01
À : K.M Ha
Cc : [email protected]
Objet : Re: Bergoz LR-BPM Monitoring system for LINAC

Hello, 

>>> On Mon, 04 Aug 2008 12:03:51 JST,  "K.M Ha" <[email protected]> wrote;
>  
> Dose any one has an experience of Bergoz 500 MHz LR-BPM for the Linac Beam
> position monitoring?
>  
> Our Linac installed over 20 sets LR-BPM on the BTL section.
> Now we are consider how to integration of monitoring system. (ex, ADC
board,
> external trigger or beam trigger .)

Once we tried Bergoz (200MHz or 500MHz), but we had difficulties in 
the hardware stabilities and triggering, etc.  (And I've heard a 
rumor he retired?)  Also, we wanted to read each electrode for the 
beam charge as well as the position, and for the higher-order beam 
profile analysis.  Instead, at KEK Linac we decided to utilize 
Windows/EPICS embedded oscilloscopes DPO7104, directly connected to 
the BPM signals, which enables 50Hz read-out as well.  You may loose 
a precision and/or a dynamic range, which can be important for FEL 
machines, etc.  But for the BT line it may be OK.  If the bunch is 
short or single, one oscilloscope may cover many BPMs in time 
direction with rf combiners.  

Another solution which employed log. amp. like Bergoz but with 3GHz 
was done at Spring8. 

> I am waiting any help!

Sorry for no direct answer.  Best regards. 

> Thanks,
> Kiman Ha,
> Pohang Light Source 

-----
Kazuro FURUKAWA <[email protected]>
 Linac&KEKB,  High Energy Accelerator Research Organization (KEK), Japan
 Telephone: +81-29-864-5200 x4316,  Facsimile: +81-29-864-0321

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System