vacuum at f11 and the interaction points
DESCRIPTION
Vacuum at F11 and the Interaction Points. Ron Moore FNAL. F11 vacuum and CDF proton halo losses – store 1289. before ferrite replacement @ F11 pressure and losses rise and fall. p intensity. F11 pressure. CDF PHSM. CDF LOSTP. F11 vacuum and CDF proton halo losses– store 1486. - PowerPoint PPT PresentationTRANSCRIPT
TeV Halo Meeting – 3 July 02
Vacuum at F11 and the Interaction Points
Ron Moore
FNAL
F11 vacuum and CDF proton halo losses – store 1289
before ferrite replacement @ F11
pressure and losses rise and fall
before ferrite replacement @ F11
pressure and losses rise and fall
CDF LOSTP
CDF PHSM
F11 pressure
p intensity
F11 vacuum and CDF proton halo losses– store 1486
after ferrite replacement @ F11
pressure reduced, no dramatic rise
losses do not rise
after ferrite replacement @ F11
pressure reduced, no dramatic rise
losses do not rise
F11 temperature
F11 pressure
CDF LOSTP
D0 Pressure Profile FromMike McGee’s Simulation
0 1.03 2.07 3.1 4.13 5.16 6.2 7.230
6.25 109
1.25 108
1.87 108
2.5 108
simulated pointsspline
Distance from IP (m)
Pre
ssur
e (t
orr)
One half of IROne half of IR
D0IG01 pressure
2.4*10-9 torr
D0IG01 pressure
2.4*10-9 torr
Average pressure = 1.26*10-8 torrAverage pressure = 1.26*10-8 torr
0 1.03 2.07 3.1 4.14 5.17 6.2 7.240
6.67 109
1.33 108
2 108
simulated pointsspline
Distance from IP (m)
Pre
ssur
e (t
orr)
CDF Pressure Profile FromMike McGee’s Simulation
One half of IROne half of IR
Average pressure = 1.22*10-8 torrAverage pressure = 1.22*10-8 torr
B0IG01 pressure
2.5*10-10 torr
B0IG01 pressure
2.5*10-10 torr
2 4 6 8 10
time (min)
0.0E0
5.0E-8
1.0E-7
1.5E-7
2.0E-7
2.5E-7
D0I
G01
pre
ssu
re r
ead
ing
(to
rr)
D0 Outgassing Rate Measurement
y = -6.4670E-008 + 3.3185E-008*x
D0 outgassing ratemeasured = 7.3*10-9 torr*liter/sec expected = 29*10-9 torr*liter/sec
CDF outgassing ratemeasured = 7.1*10-9 torr*liter/sec expected = 29*10-9 torr*liter/sec
Both outgassing rates 1/4 the expected rates
23 May 02 R. Moore - FNAL 8
Summary
• Replacing ferrite rods improved vacuum @ F11 and eliminated CDF proton loss bump
• Expected average pressure @ IPs 1.2*10-8 torr
• But, measured outgassing rates are 1/4 expected
• Models are being reexamined
• Vacuum at IPs likely better than initially believed
• IPs are not “hot spots” of poor vacuum
Proton loss rates from experiments divided by narrow-gate intensityProton loss rates from experiments divided by narrow-gate intensity
D0
CDF
Proton halo over past 4 months