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

(old version up to July 2011, latest version)

- Transmission Experiment -

The transmission experiment are done with the same electronics setup like the inelastic scattering experiments, with the difference that the electronics for the BaF2 data is ignored.

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

1. Switch on the electronics:  
  switch on NIM crate 1 and 2, VME crate 1 and 2 and Acc.Ref.Signal (see here)
2. Start MBS:  
  login to RIO7: telnet rio7
user name: ntofdaq
password: ***********
  remove interrupt request settings vmeconfig -c
  go to working directory cd mbsrun/ntot_rio6_mst_rio2_slv/
  start MBS prompter prm
  initialise MBS @start
3. Set MBS initialisation parameters:  
  login to URANIA (in another terminal window) ssh -X ntofdaq@urania
password: ***********
  go to working directory cd mbsrun/ntot_rio6_mst_rio2_slv
  open setup_vme_0.ini and setup_vme_1.ini for text editing
if you want to do some special settings
xemacs setup_vme_0.ini &
xemacs setup_vme_1.ini &
  or open setup_vme_0_short.ini and setup_vme_1_short.ini for text editing
if you only want to change only the important special settings
xemacs setup_vme_0_short.ini &
xemacs setup_vme_1_short.ini &
4. Open MBS monitoring windows:  
  login to URANIA (in another terminal window) ssh -X ntofdaq@urania
password: ***********
  go to working directory cd mbsrun/ntot_rio6_mst_rio2_slv
  open mbslog.l, mbsprint_vme_0.l, mbsprint_vme_1.l and mbs_ratios.l for monitoring
(each in its own terminal window)
tail -f mbslog.l
tail -f mbsprint_vme_0.l
tail -f mbsprint_vme_1.l
tail -f mbs_ratios.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/ntot_online
  start LEA lea -pro ntot -men
  choose right settings Source: MBS samples
Input file/node: rio7
6. Set LEA initialisation parameters:  
  login to Zirkonia (in another terminal window) ssh -X ntofdaq@zirkonia
password: ***********
  go to working directory cd lea/ntot_online
  open setup.ini for text editing if you want to do some special settings xemacs setup.ini &
7. Initialise TAPS Modules:  
  run the automatic setup of the V874B TAPS Modules (see here)
8. Switch on the detectors:  
  login to FWT31 (HV control PC) rdesktop -g 1240x900 -a 16 -k de fwt31
user name: ntofdaq
password: **********
  switch on the detectors you want to use (cf. cabeling scheme) start "isegCANHVControl" via desktop shortcut
9. Start RFIO server and client:  
  login to ZIRKONIA ssh -X ntofdaq@zirkonia
password: ***********
  go to directory for list mode data files cd /hdd2/ntofdaq/lmd/
  start RFIO dispatcher rawDispRFIO
  In MBS:
connect to RFIO Server

connect rfio zirkonia -disk
10. Start OPC client:  
  login to RIO2 telnet rio2
user name: ntofdaq
password: ***********
  go to working directory cd mbsrun/ntot_rio6_mst_rio2_slv
  start OPC readout with 1 second update time ./opc2shm 1
11. Open MBS monitoring windwos for ELBE Operators:  
  login to URANIA from any Windows PC using putty
(usually in "Start"->"Programme"->"PUTTY"; if not installed get it from "S:\Putty")
putty
Host Name: urania (leave all other values default)
login as: ntofdaq
password: ***********
  go to working directory cd mbsrun/ntot_rio6_mst_rio2_slv
  open mbs_ratios.l for monitoring tail -f mbs_ratios.l


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 /hdd2/ntofdaq/lmd/filename_.lmd first=1 size=900 -auto -rfio
 
  • note down name of first file
3. start acquisition rio6::sta acq
 
  • note down start time
4. wait ...
5. stop acquisition rio6::stop acq
 
  • note down stop time and live and dead time given at the end of mbsprint_vme_0.l and live times given at the end of mbsprint_vme_1.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 220 and switch of VME crates 1 and 2 (see here)
  • wait shortly and switch them on again
  • perform points 2. and 10. and the last step of point 9.
  • MBS message:
    "<ERROR>: number of events in TDC and ADC doesn't match ..."
  • can be ignored
  • LEA message:
    "<ERROR>: Value out of bounds of TRGTIME ..."
  • can be ignored
  • 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 resa (2x)
3. wait until reset is done -> no more network processes with rio3 and rio6 should show up netstat
4. restart MBS prompter prm
  • any other problem related to data acquisition, electronics or detectors
  • call Roland Beyer
  • any other problem related to Pb loop operation
  • call Arnd Junghans

Contact

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