Glossary

Autoreducer

Server where an instance of Post-Processing Agent is running.

Autoreduction

Automated data reduction that can be triggered when the run NeXuS data file is available. The instrument-specific autoreduction process is configured by the instrument scientist. Autoreduction is a step in the post-processing workflow.

Cataloging

Cataloging of experiment data in ONCat. Cataloging is a step in the post-processing workflow.

DAS

Data Acquisition System.

DASMON

Data Acquisition System Monitor (DASMON) is a per-beamline service that reports PV values and experiment/run meta-data to WebMon. Due to the high volume of PV updates, DASMON writes PV updates straight to the database. DASMON reports its status to WebMon for system diagnostics.

Dasmon listener

Service that subscribes to messages from DASMON and writes to the database.

HFIR

The High-Flux Isotope Reactor at Oak Ridge National Laboratory.

IPTS

Integrated Proposal Tracking System (IPTS) number is the experiment’s proposal ID that is used for grouping runs.

Live Data Server

Service that serves plots to the WebMon front-end. Livereduce and autoreduction can publish plots for a run to Live Data Server.

Livereduce

Service for live monitoring of the data stream for the creation of plots which are published to the Live Data Server.

NeXuS

Data format for neutron, x-ray, and muon science.

ONCat

Catalog for neutron experiment data at SNS and HFIR: https://oncat.ornl.gov.

Post-Processing Agent

Service that performs post-processing tasks like cataloging and autoreduction.

PV

Process Variables (PVs) are variables coming from the control system and can include sample environment variables (e.g. temperature, magnetic field), instrument geometry and experiment metadata. Subsets of PVs are used for monitoring experiments.

PVSD
Process Variable Streaming Daemon

Per-beamline service that subscribes to EPICS Control System PV:s and forwards PV value changes to the SMS. PVSD reports its status to WebMon for system diagnostics.

SMS

Stream Management Service (SMS) is a service that aggregates data from fast neutron event data and slow PVs into a data stream available for both live monitoring and file archiving. SMS reports its status to WebMon for system diagnostics.

SNS

The Spallation Neutron Source at Oak Ridge National Laboratory.

STC

Streaming Translation Client (STC) is a service that translates the experiment data stream from SMS to a NeXus data file. Triggers the post-processing workflow after the NeXus file has been created.

WebMon

Monitor for instrument status and autoreduction status at SNS and HFIR. WebMon can refer to either the whole system or the landing page at https://monitor.sns.gov.

Workflow

Experiment data post-processing workflow. The available tasks are cataloging, autoreduction and reduced data cataloging.

Workflow Manager

Service that orchestrates the autoreduction/post-processing workflow.