Fermilab Booster Operational Status:
Beam Loss and Collimation*
Robert C. Webber1
Fermi National Accelerator Laboratory, Batavia, IL 60510, USA
Abstract. Beam loss reduction and control challenges confronting the Fermilab Booster are presented in the context of
the current operational status. In Summer 2002 the programmatic demand for 8 GeV protons will increase to 5E20/year.
This is an order of magnitude above recent high rates and nearly as many protons as the machine has produced in its
entire 30-year lifetime. Catastrophic radiation damage to accelerator components must be avoided, maintenance in an
elevated residual radiation environment must be addressed, and operation within a tight safety envelope must be
conducted to limit prompt radiation in the buildings and grounds around the Booster. Diagnostic and performance
tracking improvements, enhanced orbit control, and a beam loss collimation/localization system are essential elements in
the approach to achieving the expected level of performance and are described here.
INTRODUCTION
Fri 31- MAY-2992 1 4 : 4 5 : 1 3
Efforts are underway to meet forthcoming demands
on the Fermilab Booster. In addition to supplying
IE 16 protons per hour (pph) for antiproton production
for Collider Run II, Booster is requested to provide up
to 9E16 pph for the MiniBooNE experiment [1][2].
The highest historical beam rate was about 2E16 pph,
under much less restrictive radiation constraints than
apply today. Booster currently operates near the 5E12
protons per pulse (ppp) expected by each user. The
increased hourly beam throughput will be achieved by
increasing average beam pulse rates to approximately
6 Hz. Recently Booster has provided beam at average
rates less than 1 Hz. Reduction and control of beam
loss and resulting radiation impacts is essential.
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FIGURE 1. Recent 14 weeks of operation.
Top: per pulse intensity. Middle: protons per minute
accelerated. Bottom: average beam power lost.
RECENT OPERATIONS
The Booster has operated for the past year in
support of Tevatron Collider Run II operations and
Recycler Ring commissioning. Figure 1 shows
operation for the first 14 weeks of 2002 at typical peak
pulse intensities of about 4.5E12 ppp and peak rates of
1.2E14 protons per minute (7.2E15 pph). These rates
are typically sustained for 12-16 hours per day for
antiproton production with much lighter demands the
remainder of the time. During these 14 weeks, a total
of 7.06E18 protons were accelerated corresponding to
an overall time-averaged rate of 3E15 pph.
radiation monitors (chipmunks), installed around
Booster as radiation safety interlocks, provide useful
average beam loss information that is data logged.
Performance relative to interlock trip levels is tracked
and used to project the potential trouble spots as beam
rates are increased. This information is available at
http://www-bd.fnal.gov/proton/booster/chipmunks/.
Improvements have been made in the data
acquisition and data logging aspects of the Booster
Beam Loss Monitor (BLM) system. The beam loss
observed by each of >50 BLMs during each
millisecond of each Booster cycle is measured and
individually accumulated for each time interval. The
accumulated values and the total accumulated loss are
logged to provide long-term capability of tracking
performance as a function of time in the cycle at each
BLM location. Figure 2 is a typical BLM plot that can
Several measures of beam loss performance have
been recently established or improved to track the
effectiveness of machine improvements. More than 50
Work supported by the U.S. Department of Energy under contract
No. DE-AC02-76CH03000.
^ webber@ fnal. gov
CP642, High Intensity and High Brightness Hadron Beams: 20th ICFA Advanced Beam Dynamics Workshop on
High Intensity and High Brightness Hadron Beams, edited by W. Chou, Y. Mori, D. Neuffer, and J.-F. Ostiguy
© 2002 American Institute of Physics 0-7354-0097-0/02/$ 19.00
167
radiation
levels. Data
Data on
on current
current machine
machineperformance
performance
radiation
radiation levels.
levels.
relative
to
initial
limit
settings
is
currently
relative
to
initial
limit
settings
is
currently
atat
relative to initial limit
http://www-bd.fnal.gov/proton/booster/blms/.
http://www-bd.fnal.gov/proton/booster/blms/.
http://www-bd.fnal.gov/proton/booster/blms/.
Another real-time
real-time measurement
measurement of
of total
total beam
beam
Another
Another
real-time
energy
lost
is
obtained
from
the
Booster
beam
current
energy
lost
is
obtained
from
the
Booster
beam
current
energy lost is obtained from the Booster beam
monitor.
That signal
signal isis effectively
effectively differentiated
differentiated
monitor.
monitor. That
That
effectively
differentiated
throughout
each machine
machine cycle
cycle and
and weighted
weighted by
by the
the
throughout
throughout each
each
machine
the
energy
at the
the time
time of
of the
the loss.
loss. The
The result
result is
is integrated
integrated
energy
energy at
at
the
time
of
the
loss.
The
result
is
integrated
throughout
each cycle
cycle to
to yield
yield aa total
total beam
beam energy
energylost
lost
throughout
throughout each
each
yield
value
and then
then accumulated
accumulated over
over all
all cycles
cycles to
to provide
provide
value
value and
and
then
accumulated
aa running
running
five-minute time-average
time-average of
of beam
beam power
power
running five-minute
five-minute
lost.
Typical
levels
of
150
to
250
watts
during
peak
lost.
lost. Typical
Typical levels
levels of 150 to 250 watts during peak
operations
are
shown
in
Figure
1.
Given
the
474-meter
operations
are
shown
in
Figure
1.
Given
the
474-meter
operations are shown in Figure 1. Given the 474-meter
Booster
circumference this
this represents
represents an
an average
average
Booster
Booster circumference
circumference
power loss
than 0.5
0.5 watts/meter.
watts/meter.
power
loss just
just less
less than
FIGURE
FIGURE2.
2. Color
Color gradient
gradient BLM
BLM plot.
plot.
Horizontal:
Horizontal: BLM
BLM location.
location. Vertical:
Vertical: time
time in
in cycle.
cycle.
Each shutdown,
shutdown, typically
typically 22 to
to 88 hours
hours after
after beam
beam
Each
typically
after
has been
been turned
turned off,
off, the
theradiation
radiation
level
at
a
fixed
set
of
has
level
at
a
fixed
set
of
radiation level at fixed
radiation survey
on or
or near
near the
the Booster
Booster beam
beam
radiation
survey points
points on
line is
and recorded
recorded to
to be
be compared
compared and
and
line
is measured
measured and
recorded
correlated with
real-timebeam
beam loss
lossmeasures.
measures.Data
Data
correlated
with the
the real-time
real-time
beam
loss
measures.
has been
sinceJune
June 2001.
2001.Figure
Figure33shows
shows
has
been accumulated
accumulated since
since
June
the residual
levels for
for the
the last
last 999 months
months atat
the
residual radiation
radiation levels
levels
the
last
months
“normal” long
short straight
straight sections
sections around
around
"normal"
long and
and short
short
straight
Booster, i.e.
i.e. excluding
excluding injection,
injection, extraction,
extraction, and
and RF
RF
Booster,
injection,
cavity locations.
shows data
data from
from the
the same
same
cavity
locations. Figure
Figure 44 shows
from
time period
RFcavity
cavitylocations.
locations.The
TheRF
RF
time
period at
at the
the Booster
Booster RF
RF
cavity
locations.
The
RF
cavity data
important because
because the
thepower
power
cavity
data is
is particularly
particularly important
amplifiers, located
directly on
on top
top of
of the
the cavities,
cavities, are
are
amplifiers,
located directly
directly
the
are
the highest
items in
in the
thetunnel.
tunnel. Note
Notethat
that
the
highest maintenance
maintenance items
items
Figure 33 has
logarithmic vertical
vertical scale
scale and
andthat
thatrates
rates
has aa logarithmic
logarithmic
vertical
scale
that
rates
Figure
“at contact"
contact” on
are
are "at
on or
or near
near the
the beam
beam pipe,
pipe, whereas
whereas
has aa linear
linear scale
“one
Figure
foot"
Figure 44 has
scale and
and rates
rates are
are at
at "one
“one foot”
foot”
the cavities.
cavities. This
This data
data
from
from the
data corresponds
correspondsto
tooperation
operationatat
aa time-averaged
time-averaged beam
beam rate
rate of
of 3E15
3E15 pph.
pph.
be
be generated
generated from
from either
either current
current or
or logged
logged BLM
BLM data
data
showing
ring vs.
vs.
showing color-coded
color-coded loss
loss levels
levels around
around the
the ring
time
lower
horizontal
time in
in the
the acceleration
acceleration cycle.
cycle. The
The lower
lower horizontal
band
losses
band in
in Figure
Figure 22 shows
shows widely
widely distributed
distributed losses
during
band midmidduring the
the first
first 55 msec
msec of
of the
the cycle
cycle and
and the
the band
way
losses
transition.
The vertical
vertical
wayup
upthe
theplot
plot shows
showslosses
lossesatattransition.
transition. The
bands
left
the
plot
are losses
losses due
due
bandsnear
near the
theleft
left and
and center
center of
of the
theplot
plot are
to
Booster
extraction
regions.
toapertures
aperturesat
atthe
thetwo
twoBooster
Booster extraction
extractionregions.
AA real-time
the
real-time 100-second
100-second running
running average
average of
of the
total
produced and
and
total loss
loss at
at each
each BLM
BLM location
location isis also
also produced
data
incorporated
data logged.
logged. These
These running
running averages
averages are
are incorporated
into the
the Booster
Booster Alarms
Alarms and
and Limits
Limits system
system to
into
Limits
system
to alert
alert
machine operators
operators and
and potentially
potentially inhibit
inhibit beam
beam should
machine
should
the loss
loss at
at any
any location
location exceed
exceed aa predetermined
predetermined limit.
the
exceed
predetermined
limit.
This feature
feature isis expected
expected to
to be
be the
the front-line
front-line defense
This
front-line
defense in
in
controlling component
component irradiation
irradiation and
and residual
residual
controlling
Normal Locations
mrem/hr
mrem/hr on
on contact
contact
10000
10000
10000
1000
1000
06/21/01
HO
6/21701
06/21/01
06/27/01
106/27/01
06/27/01
08/06/01
DO
8/06/01
08/06/01
08/28/01
108/28/01
08/28/01
09/10/01
SO
9/10/01
09/10/01
09/20/01
HO
9/20/01
09/20/01
02/21/02
102/21/02
02/21/02
S03/07/02
03/07/02
03/07/02
100
100
10
10
11
FIGURE3.
3. Residual
Residualradiation
radiation levels
levels on
on contact
contact at
“normal” locations
locations
FIGURE
FIGURE
3.
Residual
radiation
levels
on
contact
at "normal"
“normal”
locations around
around Booster
Booster over
over recent
recent 99 months.
months.
168
mm
rem/hr
rem/hratat1 1foot
foot
Upstream RF Cavity Locations
Upstream
Upstream RF
RF Cavity
Cavity Locations
Locations
B
a
6/21/01
6/21/01
06/21/01
6/27/01
6/27/01
^6/27/01
8/6/01
8/6/01
D 8/6/01
8/28/01
8/28/01
H 8/2
8/01
9/10/01
9/10/01
m 9/10/01
9/20/01
9/20/01
09/20/01
2/21/02
2/21/02
^2/21/02
3/7/02
3/7/02
M 3/7/02
.JnJj.irtJI—^illi.irfyfcliai
L2L2
1 _1 _
RR
L2L2 F9F_9_
1 _1 _ u u
ss
L2L2 RFR9F9
2_2_ _ d_ d
RR s s
L2L2 F1F1
2_2_ 1_1_
R R usus
L2L2 F 1F111
3_3_ _ d_
R R sds
L2L2 F1F313
3 _3 _ _ _
R R usus
L2L2 F 1F313
4_4_ _ _
R R dsds
L2L2 F1F515
4 _4 _ _ u_ u
RFRF s s
L1L1 151_5 _
4_4_ dsds
RR
L1L1 F 1F 1
4_4_ _u_u
RR s s
L1L1 F 1F_1_
5 _5 _ dsds
RR
L1L1 F 3F 3_
5_5_ _ u u
RR s s
L1L1 F 3F_3_
6 _6 _ d sd s
RR
L1L1 F 5F_5_
6 _6 _ u u
RR s s
L1L1 F 5F_5_
7 _7 _ d sd s
RR
L
L1 1 F7F7_
7 _7 _ _ u u
RR s s
L1L1 F 7F 7
9_9_ _ d_ d
RR s s
L1L1 F1F17
9_9_ 7_ _ u
R RF us s
F1 1
7_7_
dsds
*ns
300
300
300
250
250
250
200
200
200
150
150
150
100
100
50
50
50
0
0o
FIGURE 4. Residual radiation levels at one foot at RF cavity locations around Booster over recent 9 months.
FIGURE4.4. Residual
Residualradiation
radiationlevels
levelsat
at one
one foot
foot atatRF
RF cavity
cavity locations
locations around
around Booster over recent 9 months.
FIGURE
IMPROVEMENT
ACTIVITIES
IMPROVEMENT ACTIVITIES
ACTIVITIES
IMPROVEMENT
Long 5
Short 5
Long 6
Short 6
Long 66
Short 6
LongS
Long
D Long 5 D
FShort 5 F
D
D
F Short 6F
]D————rp"FT"l-l
F
H
D
I
I
D
H
F
D
D
F
F
D
D
F h
F
One
avenue
to
reduced
beam
loss
through
One avenue
avenue to
to reduced
reduced beam
beam loss
loss is
through
One
isis through
improved
orbit
control
with
the
addition
of
improved orbit
orbit control
control with
with the
the addition
addition of
of ramp
ramp
improved
ramp
capability
toto the
Booster
dipole
corrector
magnet
capability
the
Booster
dipole
corrector
magnet
capability
to the shows
Boosterfirst
dipole
corrector ramped
magnet
system.
Figure
test
results
system. Figure
Figure 555 shows
shows first
first test
test results
results of
of ramped
ramped
system.
of
correctors
attempting
to
hold
position
fixed
throughout
correctors
attempting
to
hold
position
fixed
throughout
correctors
attempting toutility
hold of
position
fixed throughout
the
cycle.
Operational
the
ramping
thecycle.
cycle.Operational
Operationalutility
utility of
ofthe
the ramping
ramping capability
capability
the
capability
will
rely
on
soundly
and
robustly
engineered
willrely
relyon
onsoundly
soundlyand
androbustly
robustly engineered
engineered software
software
will
software
with
simple
and
friendly
user
interface
with aaa simple
simple and
and friendly
friendly user
user interface
interface to
to enforce
enforce
with
to
enforce
and
facilitate
operational
discipline.
andfacilitate
facilitateoperational
operationaldiscipline.
discipline.
and
A beam
collimation
system
has
been
beamcollimation
collimation system
system has
has been
been designed
designed [3]
[3]
AAbeam
designed
[3]
and
recently
installed
in
Booster
to
and recently
recently installed
installed inin Booster
Booster to
to localize
localize
and
localize
unavoidable
beam
losses.
The
system
unavoidable beam
beam losses.
losses. The
The system
system spans
spans two
two of
of
unavoidable
spans
two
of
Booster’s
24
lattice
periods
and
includes
in
each
Booster's24
24lattice
latticeperiods
periodsand
and includes
includes in
in each
each plane
plane
Booster’s
plane
aathin
carbon
primary
collimator
followed
thincarbon
carbon primary
primarycollimator
collimator followed
followed by
by two
two 0.6
0.6
ameter
thin
by
two
0.6
copper
energy
absorbing
secondary
collimators.
meter
copper
energy
absorbing
secondary
collimators.
meter
copper
absorbing
secondary
collimators.
See
Figure
6.6.energy
Initial
tests
ofofthe
collimation
SeeFigure
Figure6.
Initialtests
testsof
thecollimation
collimation system
system are
are
See
Initial
the
system
are
just
beginning
and
an
acceptable
collimator
shielding
just
beginning
and
an
acceptable
collimator
shielding
just
beginning
an acceptable collimator shielding
design
isisstill
totoand
be
completed.
designis
stillto
becompleted.
completed.
design
still
be
Long 7
Long
Long 77
D
D
* p H F M-m-p-i—-El
D
D
Primary
Primary
Horizontal
Primary
Horizontal
Horizontal
Primary
Secondary
Primary
|_Secondary
Vertical
Vertical
Primary
Secondary
Vertical
|
Vertical
Vertical
Vertical
Secondary
Secondary
Horizontal
Secondary
Horizontal
Horizontal
T
Secondary
Secondary
Horizontal
Secondary
Horizontal
and
Vertical
Horizontal
and
and Vertical
Vertical
FIGURE
FIGURE 6.
6. Collimator
Collimator layout.
layout.
FIGURE
6.
Collimator
layout.
CONCLUSION
CONCLUSION
CONCLUSION
Booster
requested
Booster is
is still
still far
far from
from achieving
achieving the
the
Booster
is
still
far
from
achieving
the requested
requested
1E17
pph
beam
rate.
Improved
orbit
control
and
IE 17 pph
pph beam
beam rate.
rate. Improved
Improved orbit
orbit control
control and
and clean
clean
1E17
clean
collimation
to
improved
collimation system
system operation
operation will
will be
be key
key
to
improved
collimation
system
operation
will
be
key
to
improved
performance.
be
performance. Operational
Operational loss
loss limits
limits must
must
be
performance.
Operational
loss
limits
must
be
established
to
avoid
disastrous
component
radiation
established to
to avoid
avoid disastrous
disastrous component
component radiation
established
radiation
damage
damage and
and unmanageable
unmanageable maintenance
maintenance problems.
problems.
damage
and
unmanageable
maintenance
problems.
Operational
discipline
with
automated
loss
monitoring
Operational
discipline
with
automated
loss
monitoring
Operational
discipline
with
automated
loss
monitoring
and
is
important. In
In any
and limiting
limiting and
and data
data logging
logging tools
tools
is
any
and
limiting
and
data
logging
toolsera
is important.
important.
Inwith
any
case,
Booster
will
face
a
new
in
dealing
case,
Booster
will
face
a
new
era
in
dealing
with
case,
Booster
will
face
a
new
era
in
dealing
with
operations
operations in
in aaa high
high radiation
radiation environment.
environment.
operations
in
high
radiation
environment.
E:VST06L T U R N BY T U R N
REFERENCES
REFERENCES
REFERENCES
MiniBooNE,
MiniBooNE, http://www-boone.fnal.gov/.
http://www-boone.final.gov/.
http://www-boone.fnal.gov/.
MiniBooNE,
R.
Webber,
“Challenges
Fermilab Linac
Linac and
and
R. Webber,
Webber, “Challenges
"Challenges to
to the
the
R.
to
the Fermilab
Fermilab
Linac
and
Booster
Accelerators”,
Proceedings
of
the
2001
Particle
Booster
Accelerators",
Proceedings
of
the
2001
Particle
Booster Accelerators”,
Proceedings
of the# 2001
Particle
Accelerator
Conference,
IEEE
Catalog
01CH37268,
Accelerator Conference,
Conference, IEEE
IEEE Catalog
Catalog ## 01CH37268,
Accelerator
01CH37268,
pp.
pp. 2581-2583.
2581-2583.
pp.
2581-2583.
3.
and
3. A.
A. Drozhdin
Drozhdin et
et al.,
al., “Beam
"Beam Loss,
Loss, Residual
Residual Radiation,
Radiation,
and
3.
A.
Drozhdin
et
al.,
“Beam
Loss,
Residual
Radiation,
and
Collimation
and
Shielding
in
the
Fermilab
Booster”,
Collimation
and
Shielding
in
the
Fermilab
Booster",
Collimation of
and
Shielding
in the
Fermilab
Booster”,
Proceedings
the
2001
Particle
Accelerator
Conference,
Proceedings of
of the
the 2001
2001 Particle
Particle Accelerator
Conference,
Proceedings
Accelerator Conference,
IEEE
IEEE Catalog
Catalog ## 01CH37268,
01CH37268, pp.
pp. 2569-2571.
2569-2571.
IEEE Catalog # 01CH37268, pp. 2569-2571.
1.1.
1.
2.
2.
2.
Position
without
Positionwithout
without
Position
ramped
correctors
ramgejd
correctors
ramped correctors
Position
with
Positionwith
with
Position
ramped
correctors
ramped
correctors
ramped correctors
FIGURE
FIGURE5.5. Ramped
Rampedcorrectors
correctorsininaction.
action.
FIGURE 5. Ramped correctors in action.
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