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