tevatron ionization profile monitors
DESCRIPTION
Tevatron Ionization Profile Monitors. Andreas Jansson. Team rooster. Accelerator Division A. Jansson, C.Lundberg, D.Slimmer, L.Valerio, J.Zagel, T.Anderson, A. Chen, R.Dysert , S.McCormick , S. Suleimani , C.Rivetta, B.Hively , D.Miller , J.Volk Particle Physics Division - PowerPoint PPT PresentationTRANSCRIPT
9/25/2006 All experimenters meeting A. Jansson 1
Tevatron Ionization Profile
Monitors
Andreas Jansson
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Team rooster
Accelerator DivisionA. Jansson, C.Lundberg, D.Slimmer, L.Valerio, J.Zagel, T.Anderson, A. Chen, R.Dysert , S.McCormick , S. Suleimani , C.Rivetta, B.Hively , D.Miller , J.Volk
Particle Physics DivisionK.Bowie, T.Fitzpatrick, A.Bross, H.Nguyen, T.Zimmermann Z.Tang
Computing DivisionR.Kwarciany, M.Bowden
Technical DivisionH.Glass, D.Harding, V. Kashikin
Also thanks to the DOE for the RunII upgrade money!
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Motivation
• Luminosity is inversely proportional to beam size.
• Don’t dilute the emittance!
• Measure beam size turn-by-turn, especially at injection (to detect focusing errors).
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IPM detector
0.2T
MCP-1kV-100V
0V
0V
-9.9kV-10kV
All signal cables are enclosed in a Faraday cage!
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DAQ system
• CMS-QIE chip digitizes signal in tunnel.
• Serial data uplink on optical fiber.
• Receiver and data buffer in upstairs PC
• Timing + QIE clock + QIE clock supplied from PC thru cat-5E cable
Timing card(PCI)
Timingfanout
QIE cards(16x 8 ch)
Data Buffer(2x 8 links)
(PCI)
Host PC (LabView)
Service buildingTunnel
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Setup
Control PCE0 service building
IPM detector and QIE boardsTev E0 straight section
Nitrogen injection systemTev E0 straight section
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Beam profile at 150GeV
• Proton bunch #22 at 150GeV during store #4772.
• Measured beam size 1.05mm, turn-by-turn variation ~50um.
• Total signal per bunch ~1.7pC.
1 cm
30 turn average
single turn
Single bunch proton profiles
Magnet at 200A
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Flying wire comparison
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1 4 7 10 13 16 19 22 25 28 31 34
Bunch
Bea
m s
ize
(mm
)
Flying wire
IPM
y = 1.0089x
0
0.5
1
0 0.5 1
Flying wire
IPM
Known electronics problem (cross talk from timing pulse)
Comparison of vertical beam size from IPM and nearby Flying Wire.Tuning of abort gap cleaner timing had caused blow-up of certain bunches. From MAD lattice file, expect a 13% wider beam at Flying Wire. See ~1%.
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Injection turn-by-turn
0.2 0.4 0.6 0.8
0.1
0.2
0.3
0.4
Proton bunch #21 turn-by-turn
1 cm
Store #4772 Magnet at 200A
RMS profile width
0.9
1.0
1.1
1.2
1.3
[mm
]
0.0 0.5 1.0
0 10 20
FF
T0 10 20 30 40
0
5
10
15
20
25
30
0
35
turn
s
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Transfer tuning study
• September 20th: changed selected x-fer line quads
• Nominal settings• Q701 at -22A• Q701 at -42A• Q711 at -25A
NB. Q711 was found to steer the beam significantly
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Measured mismatch vectors
• Nominal settings• Q701 at -22A• Q701 at -42A• Q711 at -25A
• Need to increase Q711 by ~15A (saturation?)
• Should result in 5-10% smaller vertical emittance
• Should have very little effect on horizontal plane.
• Should have been tested this morning…
-0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
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A first look at pbars
• First look at circulating pbars during store 4963 on Tuesday September 19th !
(average over 40 turns)
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Conclusions
• Tevatron Ionization Profile Monitor see vertical injection mismatch, which can be mitigated with transfer line quad corrections.
• Should result in 5-10% smaller emittance, and corresponding increase in luminosity. May also alleviate beam-beam effect on protons.
• Still need to look at horizontal plane (need to fix tunnel hardware).
• Have seen coasting pbars, but pbar mismatch measurements (single turn) may need higher vacuum pressure.
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Extra slides
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100 turns
Four injection measurements superimposed
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500 turns
FFT of:
First 100 turnsTurn 100-400
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P150 transfer line
Plot from M. Berdnikov
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Beam profile at low beta
• Proton bunch #1 at low beta during store #4758.
• Measured beam size 0.55mm, turn-by-turn variation (noise) 20µm.
• Total signal per bunch ~1.3pC.
30 turn average
single turn
Magnet at 200A
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QIE card
• 8 channels (CMS QIE8) per board.
• Achieved noise ~1.8fC with 4’ cable.
• Data is combined with timing information, serialized by CERN GOL ASIC (rad hard) and sent thru optical fiber at 1.1Gbps data rate
• Timing fanout board cleans up and distributes clock and timing signals
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Data buffer card
• Handles 8 incoming optical links (64 channels, 1.1 GB/s of data)
• Can sparsify data on–the-fly based on timing masks
• 512MB RAM allows for– 20.000 turns of continuous
data– 90.000 turns for 72 bunches– 6 million turns for a single
bunch
• Read out thru PCI64 bus.• Two boards are used to
handle 128 channels.
• IPM buffer board doubled as prototype for BTeV L1 data buffer.
• Considered for use in MICE experiment.
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Timing card
• Produces the 15MHz (2/7 RF) QIE clock
• Decodes and transmits beamsync revolution marker + injection and trigger events
• Controls QIE settings.
396 ns (21 buckets)
p-pbar separation ~120ns
RF
2/7
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Software
• Both IPMs now have new software and firmware.
• Software/Firmware still being improved.
• Vertical IPM works pretty well.
• Horizontal IPM has some hardware problems (one dead FE board, one FE board with a sync problem, several broken channels) that require an access.
NB. REAL DATA!