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

- Transmission Experiment -

(old version up to July 2013)

DAQ preparations:

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

		trigger matching	continuous storage
1.	Switch on the electronics:
	switch on VME/NIM mixed crate in rack 1 Acc.Ref.Signal in rack 3	(see here)
2.	Start MBS:
	login to RIO42:	telnet rio42 user name: ntofdaq password: ***********
	go to working directory	cd mbsrun/ntot	cd mbsrun/ntot_cont
	start MBS prompter	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/ntot	cd mbsrun/ntot_cont
	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 only want to change only the important special settings	xemacs setup_short.ini &
4.	Open MBS monitoring windows:
	login to ZIRKONIA (in another terminal window)	ssh -X ntofdaq@zirkonia password: ***********
	go to working directory	cd mbsrun/ntot	cd mbsrun/ntot_cont
	open mbslog.l, mbsprint.l and mbs_ratios.l for monitoring (each in its own terminal window)	tail -f mbslog.l tail -f mbsprint.l tail -f mbs_ratios.l
5.	Start LEA:
	login to ZIRKONIA	ssh -X ntofdaq@zirkonia password: ***********
	initialize system variables	source .profile
	go to working directory	cd lea/ntot_online	cd lea/ntot_cont_online
	start LEA	lea -pro ntot -men
	choose right settings	Source: MBS samples Input file/node: rio42
or	Start Go4: (not for continuous storage mode)
	login to MARGE	ssh -XC ntofdaq@marge password: ***********
	go to working directory	cd $GO4WORKDIR/ntot
	start Go4	go4 ntot.hotstart &
6.	Set LEA initialisation parameters: (if LEA is used)
	login to ZIRKONIA (in another terminal window)	ssh -X ntofdaq@zirkonia password: ***********
	go to working directory	cd lea/ntot_online	cd lea/ntot_cont_online
	open setup.ini for text editing if you want to do some special settings	xemacs setup.ini &
7.	Switch on the detectors:
	login to FWK21 (HV control PC)	rdesktop -g 1240x900 -a 16 -k de fwk21 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 /hdd2/ntofdaq/lmd/
	start RFIO dispatcher	rawDispRFIO
	In MBS: connect to RFIO Server	connect rfio zirkonia -disk
9.	Open MBS monitoring windwos for ELBE Operators:
	login to ZIRKONIA from any Windows PC using putty (usually in "Start"->"Programme"->"PUTTY"; if not installed get it from "S:\Putty")	putty Host Name: zirkonia (leave all other values default) login as: ntofdaq password: ***********
	go to working directory	cd mbsrun/ntot	cd mbsrun/ntot_cont
	open mbs_ratios.l for monitoring	tail -f mbs_ratios.l

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 /hdd2/ntofdaq/lmd/filename_.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 Attention: Never stop acquisition, when the absorber is moving! -> check MBS output 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
RIO freezes or shuts down	goto measurement hut 250 and switch of VME/NIM mixed crates (see here) wait shortly and switch them on again perform points 2. and the last step of point 8.
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 RIO resl (2x) 4. 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 Maik Partzsch