MARI

This page collects information that will be useful for the implementation of the IBEX control system on MARI.

Background & Timeline

MARI is a chopper spectrometer on TS1 at ISIS. The MARI web page describes the background to the instrument.

Control System

It is proposed that MARI will migrate from the SECI control system to the IBEX control system in time for Cycle 2018/04.

MARI Equipment

The equipment listed below is used on MARI. Please add new information (e.g. new items of equipment, new notes, information about drivers, etc. to this table).

Manufacturer	Model	Type	Connection	Driver	Notes
ISIS	DAE 3	Detector Electronics	Ethernet		see DAE note
ISIS	MK3	T0 Chopper	N/C		see T0 Chopper note
ISIS	MK3	Disk Chopper	Ethernet	EPICS	see Disk Chopper note
FZJ	Analogue Drive	Fermi Chopper	RS232	EPICS	see Fermi Chopper note
GALIL	DMC2280	Motion Controller	Ethernet	EPICS	see Galil note
???	???	1 x 4-blade jaws			see Jaws note
Pfeiffer	TPG300	ISIS Vacuum System	RS232	#216	see Pfeiffer note
Eurotherm	Temperature Controller	All models at ISIS	RS-232	EPICS	see Eurotherm note
Oxford Instruments	Dilution Fridge	Cryogenic System	RS-232		see Oxford Instruments note
Oxford Instruments	Triton	Cryogen-Free Dilution Fridge	Ethernet		see Oxford Instruments note
ISIS		Transmission Monitor	via McLennan		see Transmission Monitor note
Neocera	LTC-21	Temperature Controller	RS-232	#1828	see Neocera note
ISIS	One-Off	Cryogenic Sample Changer	ENET & RS232		see Sample Changer note

Note: DAE

Main Detector banks + several fixed monitors. MARI uses DAE-3.

Note: MARI T0 Chopper

T0 chopper is generally operated in read-only mode (i.e. visiting scientists should never change its settings).
T0 is an ISIS MK3 chopper.

Note: MARI Disk Chopper

MARI has two ISIS MK3 disk choppers. User needs the ability to change speed & phase settings.
Ideally, the two choppers should seen as a single pair by visiting scientists; instrument scientists need the ability to control the two choppers independently (e.g. for diagnostic purposes).

Note: MARI Fermi Chopper

The fermi chopper is a Jülich model (FZJ - Forschungszentrum Jülich) - custom built for ISIS (therefore unique, although very similar to models installed on MAPS and MERLIN). A copy of the communications manual (PDF) is here and the operating manual here.
The control program will need to include various safety-critical condition monitoring routines (e.g. overspeed, bearing voltage out-of-range). There are some aspects of the control system which are specific to MARI and will need to be incorporated into the IOC. Ideally, they would be modular (e.g. macro, configuration file) so that the main program would be compatible between the three systems (MERLIN, MAPS, MARI).
David Keymer wrote the original VIs, which are a useful reference.
The Fermi chopper on MARI is primarily controlled via scripts. Scripts are used to calculate the frequency & phase, based on the energy (longer-term this calculation could be folded into IOC). The OPI should merely display the frequency & phase, not allow the user to change them.
Ideally, the Fermi Chopper should have a hierarchy of OPIs - at least, Simple UI (user) & Complex UI (manager). The current VI has too many details on it - instrument scientists would like to hide these. Talk with the instrument scientist about what is important when we design the IOC & OPI(s).

Note: Galil

A Galil is used to drive the jaws.

Note: Jaws

Single 4-blade jaw-set. Jaws are driven by a Galil.

Note: Pfeiffer

Model TPG 300, used for vacuum system read-back. May actually be read back via PLC.

Note: Eurotherm

Eurotherms are in use on MARI. Used to control temperature of all top-loading CCRs, Orange cryostats, heaters and furnaces.

Note: Oxford Instruments

1. Dilution fridge: Triton: Cryogen-Free Dilution Fridge

2. Historically, MARI uses dilution fridges and Blue cryostats only very rarely. Most low temperature experiments use CCRs and Orange cryostats.

Note: Transmission Monitor

MARI has a single, fixed transmission monitor.

Note: Neocera

Neocera is used only occasionally. Neocera LTC-21 Manual

Note: Sample Changer

This is a single-axis cryogenic sample changer with up to 4 positions (sample cans).
The changer is now in use and runs with a Mclennan controller via RS232/MOXI. There is still a plan to use a Beckhoff controller in future.
The changer is driven by an instrument script which has the rotation angle corresponding to each position hard-coded in.
The script will also perform a home scan on request. This is usual done when samples are mounted.
The changer should only be rotated in one direction, otherwise there is a risk the head will unscrew itself. The instrument script knows and enforces this condition.
The temperature control will be handled by a Eurotherm.
Project Details and Project Plan

MARI SECI Configs

MARI has a number of SECI configurations, which need to be migrated.

MARI Genie Scripts

Critical OpenGenie scripts for initialisation and focussing.

MARI has a number of instrument specific Genie scripts. These have now been migrated to genie_python.

MARI Notes

1. MARI does not currently use a script generator, but there is interest in having one in the future.