JLab SRF tour

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JLab SRF tour

• September 28, 2005

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Class 100 Clean Room
Left high pressure rinse
Right chemical etching A cavity string is inside
The stricter class 10 clean room is through
the left door.
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Cavity Tuning facility Danny Forehand
Bead pull iteratively measure axial electric
field profiles and deform cavities
Want uniformity among the cavities in the string
Typical uniformity begin 30-40, end 1
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Cavity tuning
Additional supports added to avoid bending of
original support
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Cavity tuning Danny Foreman (left) and Bob
Wagner
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Cavity tuning
Stiffening rings
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Cavity tuning
HOM
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Furnace Mike Lamm
Heat cavities to 600C for 10 hours to eliminate
hydrogen degassing which causes Q disease
Higher temperatures used by others make the
cavities too soft, which might be ok for smaller
cavities
A LabView program monitors the Residual Gas
Analyzer channels
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Furnace room
A titanium box which holds a cavity in
the furnace. This one shows the effects of
multiple heatings in its large grains
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Just outside the clean room door
RGA
Can attach vacuum pump to cavity inside clean
room. Pumping system contains residual gas
analyzer
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Close-up of the RGA on the pump outside the
cleanroom
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Inside the VTF assembly area
Two assemblies shown
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Inside the vertical test assembly area
Test of a single cavity
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Vertical test facility mezzanine area
Top covers of vertical test assemblies
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Vertical test mezzanine
Two top covers shown With instrumentation
Cavity string
Single cavity
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Vertical test mezzanine
Crane hook
Top cover of the cavity string assembly
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From the vertical test mezzanine looking down on
the vertical test facility
Vertical test dewars (3/6 shown) with movable
blue radiation shields
Shielding is 1 foot thick, composed of lead
bricks with 1 inch steel plate
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A vertical test dewar
RF switching network to switch among 6 test
dewars
Dewar cover
Fixed radiation shield with instrumentation
Movable radiation shield
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Vertical test dewar
Note shielding mates when closed no cracks
Movement control switches
Solenoidal winding around entire dewar under
yellow tape
Cables run through a labyrinth in the lead
shielding bricks in false floor
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Vertical test dewar
Radiation shield
Radiation shielding moves along rails, controlled
with buttons like high-bay roll door
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Vertical test facility
Another view of the shielding rails
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Vertical test dewar
Another view of the radiation shielding
Movement controls
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Vertical test facility
Magnetic switches indicate radiation shield
closed/open Interlocked personnel safety system
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Vertical test facility control room Joe Ozelis
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Vertical test facility
Some cryo stuff separated by dewar
Two additional un-(rad-)shielded small dewars at
the edge of The vertical test facility for, e.g.,
thermal measurements (no RF)
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Horizontal assembly area between horizontal test
facility (shielded cave) and clean room
Clean stuff is valved off, then mated along rails
here
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At the door to the horizontal test cave
This piece of concrete slides up on jacks for rad
shielding
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View into horizontal test facility
Shielding door
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Horizontal test cave Tom Powers, Joe Ozelis,
Mike Lamm
degaussing cables
This room has been de-gaussed note cables along
wall and surrounded by silicon-steel magnetic
shielding wallpaper on 5 sides
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Another view of the horizontal test facility
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Horizontal test cave ceiling showing passthroughs
for waveguides
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Horizontal assembly area
Some pieces of AD-MU-80 magnetic shielding for
horizontal cryostat Shielding is stiff but
wobbly. Thickness ltlt 1mm
Some instrumentation passthrough holes were cut
in-house Use rivets to connect sheets use
larger holes to account for temp shrinkage Tape
up tight with mylar tape
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Electropolishing facility
Takes longer than BCP, due to numerous safety
issues and slower layer removal, but best way to
get to highest cavity gradients
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A two-cavity string with tuners Joe Ozelis,
Mike Lamm