BNMR

Purpose

These pages describe the Data Acquisition System for the BNMR and BNQR experiments at TRIUMF

Introduction

There are two experiments defined for BetaNMR :

• BNMR running ON the BNMR high-voltage platform
• BNQR running on the BNQR high-voltage platform

Each has their own VME Crate containing a VMIC cpu and modules (see Hardware), and each runs as a separate MIDAS experiment. The DAQ software is mostly common to both experiments, differences being handled by "ifdefs".

There are two Beamline modes that BNMR and BNQR experiments can be run in:

• single channel mode where the beam is sent to one channel only, either BNMR or BNQR
• dual channel mode, where the beam is switched between the two channels BNMR and BNQR.

where the main EPICS system is used to control the beam.

For both BNMR and BNQR experiments, two types of environment are defined (cf MUSR experiments):

• Integral (Type 1)
• Time Differential or TD (Type 2)
• Combination of the above two types

Experimental Modes

A number of different Experimental modes are defined for each of Type 1 (Integral) and Type 2 (TD). These allow different experimental modes to be run (e.g. Frequency scan, Na Cell scan). Many of the modes have been rarely or never used in recent years.

INTEGRAL and TIME DIFFERENTIAL (PPG) Environmental Modes :

Table 1: Type 1 Integral Modes Mode Name Run Parameters Timing Figure Scalers 10 Same as 1f 1a 1a 1a 1b 1b 1b Freq 1f 1f NaCell 1n 1n Laser 1d 1d Camp 1c 1c Fast 1g Not available Combination of 20 and 1f LCR 1j Not available Combination of 20 and 1c

spacer Table 1b: Type 2 Differential Modes Mode Name Run Parameters Timing Figure Status SLR 20 20 *** 2a 2a 2a 2b 2b 2b 2c 2c 2c 2d 2d 2d 2e 2e 2e *** this is a spacer this is a spacer

Hardware Components

DAQ hardware components for each system (BNMR/BNQR) include the following VME modules:

Table 2: Hardware Modules for each Experiment

Module	Description	Manual	VME Base Address	BNMR	BNQR
SIS3801 version E	multichannel scaler A	SIS3801	0x2800	yes	yes
SIS3801 version E	multichannel scaler B		0x1800	yes	no
PPG (Pulseblaster)	Pulse Programmable module	PPG Spincore Pulseblaster	0x8000	yes	yes
PSM	Pol Synthesizer module (RF)	PSM / PSMII AD9857 Quadrature Digital Upconverter	0xC00000	no	yes
PSMII	Pol Synthesizer module II (RF)		0xC00000	yes	no
MVME162	68040 board, cpu runs CAMP (VxWorks)			yes	yes
VMIC	cpu runs frontend (Linux)			yes	yes

CAMP host: MVME162 68040 board, front end computer for CAMP .

Software Components

The DAQ system is based on the MIDAS package. The experiment is controlled using the MIDAS webserver (mhttpd). Due to the large number of experimental parameters required, Midas custom pages have been written for BNMR/BNQR experimenters to control and monitor their experiment. A custom logger (mdarc/midbnmr) saves the data into MUSR MUD format files, and the MUSR CAMP slow control system is used for slow controls. Analysis is done by physica.

The main software components of the BNMR/BNQR experiment are

Table 2: Software Components

Component	Purpose
frontend (runs on VMIC)	set up, operate and read hardware modules
rf_config	check PPG parameters, download program to PPG
mdarc	custom data logger saves data in MUD format
midbnmr	converts MIDAS format saved data files to save in MUD format
mheader	sends out CAMP and EPICS slow-control data to be saved in the MUD data file
fe_epics	sends experimental data to EPICS (can be read by control-room)
perlscripts	various perlscripts control changing experimental mode, checking and maintaining run numbering, etc.
autorun	automatic run controller
lcrplot	plots experimental data
physica	analyse data, reads MUD format files

The DAQ software components are started by the script start-all and stopped by the script kill-all.

DAQ Summary

The VMIC front end computer runs the frontend code which

• controls PSM,PPG, VMEIO
• acquires data from SIS MCS module(s), builds histograms
• acquires data from CAMP, EPICS
• sends the data out into the data buffer

The host computer (isdaq01)

• run all other software components
• starts/stops runs
• acquires the data from the data buffer
• logs the data
• monitors the experiment