Beam Energy Loss (BEL) Devices

BEL devices that exist on MIBEAM.

Device Function Existing Devices Notes
x:BMLOST Tick-by-tick difference in beam intensity. I:BMLOST, R:BMLOST Won't be included in new system
x:BELOST Tick-by-tick energy loss. I:BELOST, R:BELOST Won't be included in new system
x:BEL Beam Energy Loss sum for current machine cycle. I:BEL, R:BEL New system tracks the intensity after the last injection and calculates the difference in intensity rather than summing x:BELOST.
x:BELNRM Normalized (???) Beam Energy Loss I:BELNRM, R:BELNRM
x:BELTOT Integrated BEL total since last reset. I:BELTOT, R:BELTOT
X:RABEL Running average of x:BEL I:RABEL, R:RABEL
x:BEL5MA 5 min Beam Energy Loss average. I:BEL5MA, R:BEL5MA
x:BEL1HA 1 hour Beam Energy Loss average. I:BEL1HA, R:BEL1HA
x:BEL1HT 1 hour Beam Energy Loss total. Sums I:BEL for each pulse over the last hour. I:BEL1HT, R:BEL1HT
x:BTOTRS BEL totals reset. Resets totals and averages. I:BTOTRS, R:BTOTRS
x:BELnn BEL reading at the end-of-flattop. Will need to find out when RR should sample. I:BEL20, I:BEL21, I:BEL23, I:BEL29, I:BEL2A, I:BEL2B, I:BEL2D, I:BEL2E, R:BELE0, R:BELE1, R:BELE2, R:BELE3, R:BELE9 Might make sense to roll this function into cycle devices.
x:BELAnn Average BEL reading at the end-of-flattop (or RR equivalant). I:BELA20, I:BELA21, I:BELA23, I:BELA29, I:BELA2A, I:BELA2B, I:BELA2D, I:BELA2E, R:BELAE0, R:BELAE1, R:BELAE2, R:BELAE3, R:BELAE9
x:BLNAnn Normalized BEL average per cycle (???) I:BLNA20, I:BLNA21, I:BLNA23, I:BLNA29, I:BLNA2A, I:BLNA2B, I:BLNA2D, I:BLNA2E, R:BELNE0, R:BELNE1, R:BELNE2, R:BELNE3, R:BELNE6
x:BELFXT I:BEL Sample and Hold on ramp (???) I:BELFXT
x:BELON BEL calculation on/off switch I:BELON Necessary???
x:BELRMP BEL Energy Ramp (???) I:BELRMP

Cycle Devices

MI and RR both have ACNET array devices that samples the beam intensity at certain points in the machine cycle. These values are held until the next machine cycle (sometimes referred to as the "sample and hold devices" or "I:BEAMxx[] devices"). The devices are -
  • I:BEAM20[] - MI $20 cycle
  • I:BEAM21[] - MI $21 cycle
  • I:BEAM23[] - MI $23 cycle
  • I:BEAM29[] - MI $29 cycle
  • I:BEAM2A[] - MI $2A cycle
  • I:BEAM2B[] - MI $2B cycle
  • I:BEAM2E[] - MI $2E cycle
  • I:BEAM2X[] - MI last cycle
  • R:BEAME0[] - RR $E0 cycle
  • R:BEAME1[] - RR $E1 cycle
  • R:BEAME2[] - RR $E2 cycle
  • R:BEAME3[] - RR $E3 cycle
  • R:BEAME4[] - RR $E4 cycle
  • R:BEAME7[] - RR $E7 cycle
  • R:BEAMEx[] - does not exist yet, will be needed

Each index in the array is sampled on a TCLK event. Index meanings for the MI are -

Array Index Description Sampled On
0 Injection TCLK $1F (BES)
TCLK $9B (muon campus event - obsolete??)
TCLK $F3 (RRBS $A3 / RR->MI)
TCLK $F6 (RRBS $A6 / RR->Muon - obsolete??)
TCLK $F7 (RRBS $A7 / Booster->Recycler - redundant??)
1 Start of Ramp TCLK $22 (Start of MI Ramp)
2 Start of Flattop TCLK $25 (Start of MI Flattop)
3 Transfer 1 TCLK $39 (SY Extraction)
TCLK $81 (MIBS $79 MI->Muon)
TCLK $5B (obsolete)
TCLK $5C (obsolete)
TCLK $86 (obsolete)
TCLK $99 (MIBS $7E MI->Acc)
4 Transfer 2 TCLK $A9 (MIBS $74 MI->NuMI)
TCLK $F0 (obsolete)
TCLK $F2 (obsolete)
5 Transfer 3 / "Sudden Loss" TCLK $2F (MI Cleanup)

And for the RR they are -

Array Index Description Sampled On
0 Injection TCLK $E4 (Beam from Booster)
1 n/a
2 n/a
3 Transfer 1 TCLK $F3 (RRBS $A3 / RR->MI)
4 n/a
5 Transfer 3 TCLK $E8 (RR Abort ???)

It has been requested that index [5] / "transfer 3" be the last sample of beam in the machine before extraction. It appears that the current MIBEAM does this for the MI devices but not the RR devices. See dcct.c / eobGetBeamData(..).

Requirements for Recycler DCCT cycle devices from Kyle Hazzelwood (e-mail from 9-15-2015) -


Index Triggers Description
[0] $e4 + delay (ms) Injection sample
[1] $e4 + ~60ms Sample after collimation bump
[2] not used
[3] not used
[4] not used
[5] $F3 for RR->MI
$F6 for RR->Muon
Beam before first extraction


  • New device, should behave like I:BEAM2X


  • Intensity sample after the nth injection, e.g. [0] is the first injection, [1] is the second, etc.
  • Triggered the same way as R:BEAMEn0.


  • Similar to R:BEAMIn except it samples beam before extraction
  • Triggered the same way as R:BEAMEn5


  • Similar to R:BEAMXn but for Main Injector
  • Triggers:
    • $39 for MI > SY
    • $81 for MI > Muon
    • $99 for MI > Acc
    • $A9 for MI > NuMI