new timing system for lansce / marie … by los alamos national security, llc for the u.s....

Operated by Los Alamos National Security, LLC for the U.S. Department of Energy’s NNSA

Slide 1

New Timing System for LANSCE / MaRIE

(Conceptual Design)

Eric Björklund Los Alamos Neutron Science Center


P-Rad

PSR

MTS

WNR

H+

H-

LANSCE

Slide 2

  Los Alamos Neutron Science Center

  Multi-Purpose 800 MeV Proton Accelerator


P-Rad

PSR

MTS

WNR

H+

H-

LANSCE

Slide 3

  Isotope Production •  H+ 20 Hz


P-Rad

PSR

MTS

WNR

H+

H-

LANSCE

Slide 4


  Proton Radiography •  H- 2-3 pulses per day


P-Rad

PSR

MTS

WNR

H+

H-

LANSCE

Slide 5



  Ultra-Cold Neutron Source •  H- 5 pulses every 10 secs


P-Rad

PSR

MTS

WNR

H+

H-

LANSCE

Slide 6




  Material Test Stand (future) •  H+ 80 Hz


P-Rad

PSR

MTS

WNR

H+

H-

LANSCE

Slide 7





  Compression Ring for Spallation Source •  H- 20 Hz


P-Rad

PSR

MTS

WNR

H+

H-

LANSCE

Slide 8





  Compression Ring for Spallation Source •  H- 20 Hz

  Neutron Irradiation •  H- 100 Hz


Multi-Probe Hall

12 Gev Electrons

42 Kev XFEL

Optical Laser

MaRIE

Slide 9

P-Rad

PSR

MTS

WNR

H+

H-   Matter Radiation Interactions in Extremes

  Multi-Probe Materials Science Center

  Examine Dynamic Events


Timing System “Tricks”

Slide 10

  Each beam species may be independently enabled or disabled via operator switches or EPICS PVs

  Delivery Modes •  Continuous •  Single-Shot •  Multi-Shot •  Burst •  Burst of Bursts

  Cycle-Stealing •  Allows a particular beam species (the “Thief”) to be scheduled on the same cycle

as one or more incompatible beam species (the “Victims”) •  When the “Thief” species is active, the “Victim” species are disabled. •  When the “Thief” species is inactive, the “Victim” species are allowed to run


Implementation

Slide 11

  Timing Pattern Generator (TPG)

  Slave Synchronization Logic (SSL)

  Gate Enable, Inhibit, Countdown Controller (GEICCO)


Implementation – Timing Pattern Generator

Slide 12

  9 Event Generators •  1 “Master” EVG •  8 “Slave” EVGs

  Master EVG •  Synchronized with AC Zero

Crossing (120 Hz) & 2.8 MHz Ref. •  Contains the pattern for the entire

“Super-Cycle” •  120 sequences (one per machine

cycle)

  Slave EVGs •  One for each beam species •  Contains single sequence for the

events belonging to that beam species

•  Sequence may span several machine cycles.


Implementation – Gate Enable, Inhibit, Countdown Controller (GEICCO)

Slide 13

  Implemented in FPGA of a cRIO with embedded EPICS

  Controls when the slave EVGs get triggered. •  Console Switches •  Delivery Mode •  Cycle Stealing

  Master EVG sends trigger to GEICCO for each beam species scheduled for this cycle.

  GEICCO determines whether beam species can occur, and if so sends a trigger to the Slave EVG’s “AC In” port.


Implementation – Slave Synchronization Logic

Slide 14

  GEICCO’s I/O modules have 10 MHz clock •  Potential for 200 nSec jitter between

incoming and outgoing triggers

  SSL removes the jitter and re-synchs the slave trigger to the 2.8 Mhz reference.


One More Wrinkle

“Dynamic” Experiments   “Filming” turbulence, phase transitions, stress response, etc. in real-

time.

  Large degree of uncertainty (~3 milliseconds) between when the process is started and when the event of interest occurs.

  Probe window can be at most 1 millisecond long.

  Intermediate sensors (pressure, temperature, etc.) can frequently narrow the uncertainty to around 500 microseconds, but the overall start-to-end uncertainty remains high.

  Last part of the beam sequence (the part where the beam comes on) must be de-coupled from the first part of the sequence (where the “start” trigger is generated), and even from the normal AC-driven machine cycle.

Slide 15


Yet Another Wrinkle

Dual Redundant Timing Masters

Slide 16


Yet Another Wrinkle

Why?

Slide 17


Yet Another Wrinkle

Why?

Slide 18

  High degree of confidence we won’t get it right the first time (or the 2nd,....)


Yet Another Wrinkle

Why?

Slide 19

  High degree of confidence we won’t get it right the first time (or the 2nd,....)

  Consequences of not getting it right are not negligible.


Yet Another Wrinkle

How?

Slide 20


Yet Another Wrinkle

How?

Slide 21

  Use Redundant IOC facility.


Yet Another Wrinkle

How?

Slide 22

  Use Redundant IOC facility.

  Use Fanout/Concentrator for event link switch.

new timing system for lansce / marie … by los alamos national security, llc for the u.s....

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