Contact

Dr. Roland Beyer
PostDoc / Beamline scientist
Nuclear Physics
roland.beyerAthzdr.de
Phone: +49 351 260 - 3281

Data Acquisition Manual: How to run Neutron Time of Flight Measurements at nELBE

- Elastic Scattering Experiment -



DAQ preparations:

To run neutron time of flight measurement you first have to do some preparations:

1. Switch on the electronics:  
  switch on
VME and NIM crate in rack 2
NIM crate 2 and Acc.Ref.Signal in rack 3
(see here)
2. Start MBS:  
  login to RIO41: telnet rio41
user name: ntofdaq
password: ***********
  go to working directory cd mbsrun/irmm/
  start MBS mbs
  initialise MBS @start
3. Set MBS initialisation parameters:  
  login to ZIRKONIA (in another terminal window) ssh -X ntofdaq@zirkonia
password: ***********
  go to working directory cd mbsrun/irmm
  open setup.ini for text editing
if you want to do some special settings
xemacs setup.ini &
  or open setup_short.ini for text editing
if you want to change only the important special settings
xemacs setup_short.ini &
4. Open MBS monitoring window:  
  login to ZIRKONIA (in another terminal window) ssh -X ntofdaq@zirkonia
password: ***********
  go to working directory cd mbsrun/irmm
  open mbsprint.l for monitoring (in another terminal window) tail -f mbsprint.l
5. Start LEA:  
  login to ZIRKONIA ssh -X ntofdaq@zirkonia
user name: ntofdaq
password: ***********
  initialize system variables source .profile
  go to working directory cd lea/irmm/irmm_online
  start LEA lea -pro nel -men
  choose right settings Source: MBS samples
Input file/node: rio41
6. Set LEA initialisation parameters:  
  login to ZIRKONIA (in another terminal window) ssh -X ntofdaq@zirkonia
password: ***********
  go to working directory cd lea/irmm/irmm_online
  open setup_loc.ini for text editing if you want to do some special settings xemacs setup_loc.ini &
7. Switch on the detectors:  
  login to FWK103 (HV control PC) rdesktop -g 1240x900 -a 16 -k de fwk103
user name: ntofdaq
password: **********
  switch on the detectors you want to use (cf. cabeling scheme) start "isegCANHVControl" via desktop shortcut
8. Start RFIO server and client:  
  login to ZIRKONIA ssh -X ntofdaq@zirkonia
password: ***********
  go to directory for list mode data files cd /hdd1/ntofdaq/lmd/
  start RFIO dispatcher rawDispRFIO
  In MBS:
connect to RFIO Server

connect rfio zirkonia -disk
9. Start monitor DAQ and monitoring window for ELBE Operators:  
  see Monitor DAQ manual  



Running the DAQ:

Now the measurement can be started. This has to be done in the MBS prompter (prm):

  in LEA
1. start LEA analysis click Analyze events
  in MBS
2. open list mode file open file size=900 -auto -rfio
if it is the first file enter:
open file /hdd1/ntofdaq/lmd/irmm_.lmd first=1 size=900 -auto -rfio
 
  • note down name of first file
3. start acquisition sta acq
 
  • note down start time
4. wait ...
5. stop acquisition stop acq
 
  • note down stop time and live and dead time given at the end of mbsprint.l
6. close list mode file close file
 
  • note down name of last file



If any problem occurs:

Problem Solution
  • one or more of the RIOs freezes or shuts down
  • goto measurement hut 250 and switch of VME crate in rack 2 (see here)
  • wait shortly and switch them on again
  • perform points 2. and the last step of point 8.
  • iseg HV Control shows current trip for one or more detectors
If Vmeas is stable:
  • use button 3 "Status3 software current trip" to reset Status
If Vmeas is not stable:
  • Switch the channel off until the source for the high count rate is eliminated (e.g. while beam tuning)
If Vmeas remains unstable:
  • Replace the HV divider of the PMT
If Vmeas remains unstable:
  • Replace the PMT
  • DAQ is frozen
1. leave MBS prompter CTRL+C
2. reset RIOs resl (2x)
3. restart MBS prompter mbs
  • any other problem related to data acquisition, electronics or detectors
  • call Roland Beyer
  • any other problem related to Pb loop operation
  • call Arnd Junghans or Mike Partzsch

Contact

Dr. Roland Beyer
PostDoc / Beamline scientist
Nuclear Physics
roland.beyerAthzdr.de
Phone: +49 351 260 - 3281