Experimental Facilities Division ANL-ORNL

SNS Experimental Data Standards(Status)

Richard Riedel

SNS Data Acquisition Group Leader

Experimental Facilities Division ANL-ORNL

DAS Group Mandate (From shared DCD)

• Provide electronics for detectors and controls

• Provide control software

• Provide basic analysis software as needed for monitoring of experimental performance.

Experimental Facilities Division ANL-ORNL

Instrument Private Network Links

CISCO 3524Ancillary Controls

EPICS GatewayChoppers

Sample Environment

SwitchFirewall

Control Computer Analysis Computer

Site

Eth

erne

t

192.168.XXX.XX

Local RaidDetector

Electronics

Fiber Channel, Switched Fabric

Wireless Link

Experimental Facilities Division ANL-ORNL

Control Software Highlights

• XML based communications language

• Modular Structure with well defined interfaces

• O.S. and platform restrictions more severe than analysis software.

Experimental Facilities Division ANL-ORNL

Control Software Interfaces

Control Computer Satellite Computer

File S

ys tem

ServerClient

GUI

LabviewEpicsVBC++Java

Client API Server APIs

Experimental Facilities Division ANL-ORNL

Control Software Interfaces

Control Computer

Analysis Computer

New Run File

PreprocessorCluster

Monitor Data

Lots of Data

Analysis Computercan determine next

experimental parameters

Experimental Facilities Division ANL-ORNL

Control Software Requires Same Infrastructure as Analysis Software

• Version control (CVS)

• Bug control and reporting

• Code review and testing procedures

Experimental Facilities Division ANL-ORNL

Data Components

SearchableDatabase(Meta-data)

Experimental Record

Meta-Data

Data

Correctional Data

Background DataNormalization Data

Runfile

Experimental Facilities Division ANL-ORNL

Data Sources

Control Computer

Detector Electronics

Ancillary Controls:(Slits, Beam Monitors)

Choppers

Sample Environment

SNS Data Base(User Info)

Experimental Facilities Division ANL-ORNL

Data Format Requirements

• Same for all instruments

• Adaptable to both histogrammed and pulse (individual events) formats

• Extraction of parametric data should be simple—and fast (pointer tables?…..)

• Read, write speeds >95% of native C code.

• Prefer existing standard

Experimental Facilities Division ANL-ORNL

Data Size Estimates

Parameter Backscat. Spect. Magnetism Reflect.

Liquids Reflect. Powder Diff. Single Xtal Diff. Chopper Spect.

Disord. Mat’ls Diff.

Spatial pixel

area (cm2)1 0.01 0.01 1.2 0.01 6.25 1.2

Total # of pixels 7,000 10,000 10,000 230,000 5,000,000 50,400 150,000Time of flight precision (microsec)

1 10 10 0.5 1 0.2 0.2

Max # of time channels

8,400 1,500 1,500 60,000 1,000 2,000 1,000

Max instantaneous rate/pixel (cts/sec)

4,000 1.3 x 106 1.30 x 106 40 3.8 x 104 30,000 2,000

Max total instantaneous rate (cts/sec)

3 x 107 1.2 x 108 1.2 x 108 1.4 x 106 1.7 x 107 1.5 x 109 8.4 x 107

Max time-average rate/pixel (cts/sec)

12 6.2 x 105 6.2 x 105 4 2.8 4 360

Max total time-average rate (cts/sec)

8.5 x 104 5.9 x 107 5.9 x 107 1.4 x 105 1.4 x 107 2.0 x 105 1.6 x 107

Total # of channels per data set

5.9 x 107 1.5 x 107 1.5 x 107 1.4 x 1010 5.0 x 109 1.0 x 108 1.5 x 108

Typical # of channels per data set

6 x 107 7 x 106 7 x 106 3 x 109 1 x 109 5 x 107 8 x 107

Total # of counts per data set

7.7 x 107 3.5 x 109 3.5 x 109 1.2 x 108 4.3 x 109 2.4 x 108 3.0 x 1010

# of data links

1 6 6 1 2 1 2Preprocessor Memory Required

256MB Ch / 640MB Ev

5GB per board Ev. / 256MB ch.

5GB per Board Ev. / 256MB ch.

1GB Ev only 10GB per Board (Ev. Or

Ch.)

2GB ev. / 512MB ch.

1GB per Board (ch. Only)

Experimental Facilities Division ANL-ORNL

Constraints

• Speed and file size rule out HDF4 based APIs.

• Data size rules out ASCII

• ASCII-binary mix or all binary are viable options

Experimental Facilities Division ANL-ORNL

What is in it? (Direct and Indirect)

• General

• Sample state (includes hardware I.d.s of controllers)

• Instrument state (chopper phase) slit data

• Data

• Background

• Normalization files

• Run file

Experimental Facilities Division ANL-ORNL

Leaning toward?…….

• Nexus is strongest contender.

• Formal decision waiting on requirements documents and testing

• Testing includes storage simulated data and meta sets from the seven approved instruments.

Experimental Facilities Division ANL-ORNL

Present SNS Shared Focus

• Define meaning of SNS “supported” software

• Define Quality control ---testing, revision control, bug reporting internal and external.

• Define data format

Experimental Facilities Division ANL-ORNL

SNS supported

• Documented testing (known input data)

• Peer review

• Support

• Upgrade and bug management

• Documentation packet

Experimental Facilities Division ANL-ORNL

Software Documentation

• Requirements document

• Users manual

• Technical reference document

• Testing documentation

• Web site management

• Review committee sign off procedure