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The LARP Collimation Program

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Title: The LARP Collimation Program


1
The LARP Collimation Program
US LHC Accelerator Research Program
BNL - FNAL- LBNL - SLAC
  • 19 June 2008
  • LARP DOE Review - LBNL
  • Tom Markiewicz/SLAC

2
Three Collimation Tasks Ended in FY07Investigate
Efficiency, Reliability and Design of Phase I
Collimation
  • Use RHIC data to benchmark the code used to
    predict the cleaning efficiency of the LHC
    collimation system and develop and test
    algorithms for setting collimator gaps that can
    be applied at the LHC
  • Responsible Angelika Drees, BNL
  • Understand and improve the design of the tertiary
    collimation system that protects the LHC final
    focusing magnets and experiments
  • Responsible Nikolai Mokhov, FNAL
  • Use the facilities and expertise available at BNL
    to irradiate and then measure the properties of
    the materials that will be used for phase 1 and
    phase 2 collimator jaws
  • Responsible Nick Simos, BNL

3
FY08 FY09 LARP Collimation Program
  • Design, Build Test 1 of 3 Phase II Secondary
    Collimator Prototypes
  • that can potentially be used in some or all of
    the 30 reserved Phase II Secondary Collimator
    lattice locations as a part of the LHC Phase I
    Luminosity Upgrade
  • Responsible Tom Markiewicz, SLAC
  • Experimentation to Investigate Possible Use of
    Crystals as High Efficiency Primary Collimators
  • in the LHC and other high intensity proton rings
    (PS2, MI)
  • T980 at FNAL Tevatron- Responsible Nikolai
    Mokhov, FNAL
  • added in FY08 after Spring 08 CM
  • CRYSTAL at the SPS Responsible Steve Peggs,
    BNL
  • added as New Initiative after Fall 09 CM

4
LHC Collimation Requirements
  • LHC Beam Parameters for nominal L1E34cm-2s-1
  • 2808 bunches, 1.15E11 p/bunch, 7 TeV ? 350 MJ
  • Dt25ns, s200mm (collisions)
  • System Design Requirement Protect against
    quenches as beam is lost
  • Design shielding for expected lttgt30hr or 3E9 p/s
    or 3.4kW
  • Design collimator cooling for t 1 hour or 8E10
    p/s or 90kW
  • Plan for occasional bursts of t 12 min or 4E11
    p/s or 450kW
  • abort if lasts gt 10 sec
  • Collimation system inefficiency
  • Inefficiency Max Loss Rate lt Quench Loss Rate
  • dQ/dV 1.5mW/gm in SC coil causes quench
  • Estimate inefficiency of collimation system via
    SIXTRACK program
  • Determine minimum required inefficiency via
    FLUKA/MARS
  • 8E6 p/s on TC will quench Q3 in triplet ? 2E-5
    inefficiency _at_ 4E11 p/s loss

5
The LHC Collimation System
  • Betatron Collimation in IR7
  • 3 short (60cm) Primary collimators (H,V,S) at
    6s per beam
  • 11 long (1m) Secondary Collimators (various
    angles) at 7s per beam
  • Momentum Collimation in IR3
  • 4 long (1m) Secondary collimators per beam
  • Other
  • 1m HV Tungsten Tertiary Collimators at
    Experimental IRs at 8.4s
  • 1m Cu or W Absorbers at 10s
  • Warm Magnets, tunnel and shielding absorb
    remainder of lost beam energy
  • Non-Accident Engineering Challenge
  • The first long secondary collimator downstream of
    the primary system must absorb much more energy
    than any other secondary in the system since
    80-85 of list particles interact inelastically
    in the 6s primaries
  • The deformation specification of the collimator
    jaw is set at 25mm in order to maintain system
    efficiency

Accident Scenario When beam abort system fires
asynchronously with respect to abort gap (armed
HV trips accidentally) 8 full intensity bunches 1
MJ will impact collimator jaws
6
Phase I and Phase II Collimation
  • Phase I Use Carbon-Carbon composite as jaw
    material
  • 60cm/1m Carbon undamaged in Asynchronous Beam
    Abort
  • Low energy absorption of secondary debris eases
    cooling tolerances
  • 6-7 kW in first 1m C secondary behind of
    primaries when dE/dt90 kW
  • 10 sec 450 kW load handled as a transient
  • Low, but adequate collimation efficiency to
    protect against quenches at lower L expected at
    startup
  • High, but adequate machine impedance for stable
    operation at low L expected at startup
  • Phase II Metal collimators into vacant slots
    behind each Phase I secondary
  • Good impedance and efficiency allowing LHC to
    reach design L 1E34
  • After stable store open Carbon jaws and close
    Metal jaws
  • Jaw will be damaged how badly? what to do?
  • More energy from primaries will be absorbed
    cooling deformation
  • only pertains to first collimator per beam in
    betatron cleaning insertion!

7
IR7 Collimator Layout 11 Carbon Phase I and 11
Metal Phase II Secondary Collimators per beam in
IR7
8
Impedance Limits LuminosityCarbon Collimators
Dominate Impedance
Unstable
Stable
? Limitation at about 40 of nominal intensity
(nominal b, full octupoles)
9
SIXTRACK simulationcompare materials
collimation efficiencytradeoff with mechanical
performance
Yunhai Cai
  • High Z materials improve system efficiency but
    generate more heat
  • Copper eventually selected for SLAC Phase II
    design because of its high thermal conductivity
    and ease of fabrication
  • Available length for jaws is about 1 meter,
    although gain after 50cm is minimal

Carbon
Copper
Similar result was obtained by Ralph Abmann
10
LARP Rotatable Collimators for LHC Phase II
Collimation
US LHC Accelerator Research Program
BNL - FNAL- LBNL - SLAC
  • Adapt rotatable NLC design concept to LHC RC
  • Build and test one collimator jaw with 10kW
    resistive heaters to verify thermo-mechanical
    performance
  • Minimize deflection when absorbs with 60kW for 10
    sec
  • Build a full collimator test it at CERN
  • 2009 Delivery
  • Gene Anzalone (CAD), Eric Doyle (ME-FEA), Lew
    Keller (FLUKA), Steve Lundgren (ME), Tom
    Markiewicz (Phys) Jeff Smith (PD)

11
NLC Consumable Collimator 32cm diameter, thin,
rotatable jaws 500 to 1000 hits with no cooling
Note short high-Z material.
lt 10 W per jaw gtradiative cooling!
6.0
Aperture control mechanism 5mm accuracy
stability
Movers align chamber to beam based on BPMs
Alignment BPMs upbeam down
12
Exact Nature Extent of Damaged RegionBiggest
DESIGN RISK to RC
Thin Cu sample in FFTB electron beam at SLACHole
Beam Size
2000um 500 kW 20 GeV e- beam hitting a 30cm Cu
block a few mm from edge for 1.3 sec (0.65 MJ)
FNAL Collimator with .5 MJ
13
SLAC Timeline for RCRotatable Collimator
PrototypePre-LAUC Plan
  • 2004 Introduction to project
  • 2005 Conceptual Design Phase II RC using FLUKA,
    SIXTRACK and ANSYS External Design Review
    changes recommended
  • 2006 Hire full time ME and designer Improved
    Conceptual Design fabricate winding tooling,
    2D/3D drawings of test and final parts, braze two
    20cm test pieces collimator test lab set up
    begins
  • 2007 Vacuum test section test parts, braze and
    test 3rd 20cm unit, develop and build rotation
    mechanism, complete Cu/Mo shaft-hub assembly
    hire first postdoc preliminary design RF shield
    design acquire CERN Phase I collimator
  • 2008 Fab 1st full length jaw equip CERN
    collimator with steppers and LVDTs thermal
    tests of single jaw more tests to improve braze
    process, begin to fabricate two more mandrels,
    jaws, shafts, rotation devices, for RC
  • 2009 Finish all parts and assemble into a vacuum
    tank compatible with Phase I adjustment
    mechanism RC Mechanically test RC, ship and
    install in SPS/LHC
  • 2010 Collimator tests at LHC Final drawing
    package for CERN
  • 2011 Await production installation of chosen
    design(s) by CERN
  • 2012 Commissioning support
  • Main Deliverables
  • Thermal tests of single collimator jaw
  • Construct and mechanically test full RC prototype
    to be sent to CERN

14
LHC Phase II Base Concept physical
constraints current jaw design
20 facets
  • beam spacing geometrical constraint
  • Length available 1.47 m flange - flange
  • Jaw translation mechanism and collimator support
    base LHC Phase I
  • gt10 kW per jaw Steady State heat dissipation
    (material dependent)

Glidcop Cu Mo
Cu coolant supply tubes twist to allow jaw
rotation
Helical cooling channels 25mm below surface
Hub area
Cantilever Mo shaft _at_ both ends
15
Cu Jaw-Cu Hub-Mo Shaft Design
2mm shaft-jaw gap gives x5 improvement in thermal
deformation over solid shaft-jaw design 1260 um ?
236 um (60kW/jaw, t12min) 426 um ? 84 um
(12kW/jaw, t60min) Rather than Cu, Moly shaft
improves Gravity sag x3 200 um ? 67
um Thermal bulge 30 339 um ? 236 um
16
Status of RC Program
  • Jaw support rotation mechanism COMPLETE (June
    2007)
  • First full single jaw-hub-shaft unit COMPLETE
  • Preliminary tests indicate performance in accord
    with FEA to 10
  • Work to complete RC1
  • Finalize RF design
  • Test a few new concepts to simplify machining
    brazing process
  • Order parts for 2-3 new jaws
  • Build 2 jaws, supports, RF features in new vacuum
    tank
  • Metrology vacuum tests
  • Mechanical motion tests on existing CERN system
  • Ship to CERN

17
Internally actuated drive and jaw mount for
rotating after beam abort damages surface
Completed 27 May 2007
  • Universal Joint Drive Axle Assembly
  • Thermal expansion
  • Gravity sag
  • Differential transverse displacement

Rotation drive with Geneva Mechanism
18
Brazing Each Moly Shaft End to a Central Copper
Hub
  • After much RD, developed method to braze
    Molybdenum to Copper for inner shaft

Shaft halves
19
Three Braze Cycles
  • Three main brazing steps.
  • Brazing materials set to melt at gradually lower
    temperature.
  • 1.) Braze each shaft end to a central half-hub
  • 2.) In one go
  • Braze shaft half-hubs to Mandrel
  • 25 Gold, 75 Copper
  • Braze copper cooling coil to Mandrel
  • 35 Gold, 65 Copper
  • 3.) Braze jaw quadrants to mandrel surface after
    mating mandrel OD and jaw quadrant ID
  • 50 Gold, 50 Copper

20
Inserting Molybdenum Shaft Ends into Mandrel then
Wind Coil Around Mandrel with Ends of Coil
Protruding Out Each End
Original Grooved Mandrel destroyed by vendor when
drilled out to accept shaft resulting in 2 month
delay
21
Braze Step1 Shaft Assembly Coil to Mandrel
  • On support stand and ready for insertion in
    baking oven
  • Carbon block used to hold thermally expanding
    copper against central hub and shaft (moly and
    copper)
  • Next time may use carbon block full length of
    mandrel

22
Filling Coil-Mandrel Keystone Gaps
  • Three brazing cycles needed before coil-mandrel
    keystone gaps filled adequately
  • On 3rd cycle excess braze material attaches
    support stand to mandrel, which warps

Pix of 2nd braze cycle
23
Recovery after Excess Braze Material Attaches
Mandrel Shaft to INOX Inconel Braze Supports
Machine to constant diameter
Bending fixture
Bent mandrel before hacksaw
24
Measure Machine Quadrants to Mandrel. Assemble
Braze
  • Using 50-50 Au-Cu brazing material ()

25
Results of Jaw Brazing 22 April 2008
  • Looks good!
  • Experience has made us consider
  • Full round jaw segments
  • Over-sizing parts cutting down to proper radius
  • Several ideas to minimize keystoning when coil
    wound on mandrel

26
Machine Flat Facets and Groove for Heater Test
Final brazing was a success! Flat facets and
grooves for heater tests and thermocouple holes
have been machined. Within 25 micron tolerance
along facet surface.
27
First Full Length Jaw Thermal Tests
Use two 5 kW heaters placed along jaw surface
(simulating steady state beam heating) Sensors
measure thermal deflection to confirm ANSYS
simulations. Deflection toward beam during beam
heating must be minimized.
28
Thermal test setup
Jaw in support stand
Heaters strapped on jaw
Extra heater
Heater cable
Water flow tube
Water flow control
29
Measure jaw thermal expansion
Heaters attached on bottom (jaw rotated 180
degrees from previous slide
30
Comparison of Sagitta Temperature with ANSYS as
a function of angle wit respect to heater
  • Jaw with two 5 kW heaters modeled
  • Includes accurate representation of
  • Water flow/temp change
  • Material properties
  • Thermal expansion
  • Heat flow / thermal conductivity
  • Data 10 larger than ANSYS

31
Phase I Graphite Collimator Bought from CERN
mounted and set up in our lab
LVDT Controller
Stepper Controller
32
Motion Control
Open
  • CERN LabView control software modified and
    working with our controllers.
  • Verified full motion of Phase I jaws as test of
    SLAC steppers controllers
  • Will test steppers for increased weight of copper
    jaws and be sure LAR jaws can be controlled by
    CERN software before shipping

Closed
33
RF Design
Short RF Test Jaw with End Socket mounted
Bearing Race
  • UNDER STUDY
  • Contact Resistance Measurements
  • Stretched Wire Impedance Measurements
  • Trapped mode study using Omega3P

SiN4 balls
Low resistance RF contact
Slot for Spiral RF Spring
34
Contact Resistance Experimental Setup for Spira
Spring
35
First results with Spira-Shield Spring
36
Stretched Coil Impedance Measurements
LCR meter obtained (better than Network Analyzer
for low frequency impedance) First step just to
measure inductive by-pass in graphite and copper
and confirm CERN results
  • Agreement between measurement and theory not as
    good as CERN
  • Much more planned for these measurements!

37
Preliminary results onTM monopole modes-Omega3p
run
Beam pipe R42mm, Fc(TE11)2.1GHz,
Fc(TM01)2.73GHz
38
Phase II Task Summary
  • RC Design essentially complete and first jaw
    constructed and tests according to calculation.
    In principle all procedures, methods, parts
    finalized and need only push the button to
    fabricate first full prototype.
  • However, its not over until the fat lady sings
  • In June 2006 DOE was told
  • Expect thermal tests and completely tested RC1
    device by end of FY06 and mid-FY07,
    respectively
  • In June 2007 DOE was told
  • Expect thermal tests to begin and completely
    tested RC1 device by end of FY07 and end-FY08,
    respectively
  • In June 08 DOE is being told
  • Expect RC1 device mid-CY09

39
Experimentation to Investigate Possible Use of
Crystals as High Efficiency Primary Collimators
in the LHC and other high intensity proton rings
(PS2, MI)
US LHC Accelerator Research Program
BNL - FNAL- LBNL - SLAC
  • T980 at FNAL Tevatron- Responsible Nikolai
    Mokhov, FNAL
  • CRYSTAL at the SPS Responsible Steve Peggs,
    BNL
  • BNL, FNAL and SLAC collaborating on both
    experiments with historical groups
  • RD22 team from CERN-Italy-Russia (1990-97 SPS,
    2007 H8 extracted line)
  • Fermilab team (1993-98, 2005-2007 Tevatron)
  • BNL Team (2005 RHIC)

40
Particle-crystal interaction
  • Possible processes
  • multiple scattering
  • channeling
  • volume capture
  • de-channeling
  • volume reflection

41
Angular beam profile as a function of the crystal
orientation
The angular profile is the change of beam
direction induced by the crystal
The rotation angle is angle of the crystal
respect to beam direction
5
1
1
The particle density decreases from red to blue
3
1 - amorphous orientation 2 - channeling 3
- de-channeling 4 - volume capture 5 - volume
reflection
4
42
Can the H8 Result be repeated in a Colliderusing
edge of crystal?
  • Tevatron T-980 Mission Statement
  • We propose an experiment at Fermilabs Tevatron
    to measure the predicted improvement in
    collimation efficiency that could be obtained by
    replacing amorphous primary collimators with bent
    crystals.
  • A repeat of 2005-2007 using existing but improved
    instrumentation
  • 2005 Crystal checked (so-called O-shaped)
    reinstalled
  • Goniometer rebuilt problems found fixed
  • Scintillator flying wires commissioned
  • Considering the unique possibility provided by
    the Tevatron Collider, and having already
    established fruitful collaborative efforts on
    crystal characterization, tests and use for
    collimation, we propose to test and confirm
    models of multi-turn dynamics with crystals by
    exploiting channeling and newly understood
    phenomena such as volume reflection as well as to
    further study collimation.
  • Add tracking in Roman Pots
  • Uncertainty in length of Tevatron run leads
    Scandale et al to propose tracking based CRYSTAL
    experiment in SPS which is APPROVED for 2009
    running

43
E0 Crystal Collimation Layout
23.731 m
33.115 m
44
Beam Instrumentation E1 Scintillation Counters

45
Flying and Crawling Wires at E11

J. Zagel
46
STRUCT/CATCH Simulations Profiles at 9
CriticalLocations in Tevatron with O-Shaped
Crystal

E03 collimator
E11 flying wire
First turn, all collimators are retracted
A. Drozhdin
47
2008 PLANS
  • June Installation in the tunnel during a
    mini-shutdown (two shifts).
  • June August Beam tests (4 End-of-Store
    studies, 8 hours). Tuning the system and
    measuring beams and losses.
  • August - December 12 hours of beam tests.
    Thorough EOS studies of beam dynamics and
    collimation efficiency of upgraded and tuned
    setup aiming at reproducibility and after a BOS
    tests - routine use of crystals in the Tevatron
    stores. In the same period, planning and
    manufacturing of new crystals, hardware and
    electronics for measurements in Configuration 3
    and 4 will be performed to be ready for
    installation in the tunnel during the Spring 2009
    shutdown.
  • 2009-2010 Configurations 3 and 4, scope and beam
    requests depend on outcome of beam tests and are
    subject to FNAL Director and CDF/D0 review and
    2009-2010 run plans.

48
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49
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50
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51
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52
LARP Participation in T980 _at_ FNAL CRYSTAL _at_ SPS
  • Opportunity to participate in cutting edge
    collimator RD for minimal cost
  • Large and highly efficient scattering from a
    thin, robust primary collimator VERY good for any
    high intensity beam
  • T980 LARP contribution for pays for effort, HW
    rebuild, travel
  • subsidized by FNAL
  • CRYSTAL contribution for 1 of 2 Roman Pots part
    of tracking system/electronics, modest of
    finite duration
  • both Pots Silicon will be returned to Tevatron
  • 200k in FY2008 followed by travel costs for
    participation
  • Management challenge to minimize parochial
    attitudes and to consider BOTH experiments as
    part of study
  • Good communication between Mokhov, Scandale,
    Peggs Markiewicz
  • Weekly SLAC-BNL and BNL-CERN meetings

53
Bonus Slides
54
CERN Collimation Plan Schedule
  • 0) Assume SLAC LARP develops Rotatable Collimator
  • 1) Develop TWO other complementary designs
  • 2) Develop a test stand for the three designs
  • 3) Fabricate 30 Phase II collimators of chosen
    design 6 spares
  • The target schedule for phase 2 of LHC
    collimation
  • 2005 Start of phase 2 collimator RD at SLAC
    (LARP) with CERN support.
  • 2006/7 Start of phase 2 collimator RD at CERN.
  • 2009 Completion of three full phase 2 collimator
    prototypes at CERN and SLAC. Prototype
    qualification in a 450 GeV beam test stand at
    CERN.
  • 2010 Installation of prototypes into the LHC and
    tests with LHC beam at 7 TeV. Decision on phase
    2 design and production at end of year
  • 2011 Production of 36 phase 2 collimators.
  • 2012 Installation of 30 phase 2 collimators
    during the 2010/11 shutdown. Commissioning of
    the phase 2 collimation system. LHC ready for
    nominal and higher intensities.
  • RED One year slip from recent white paper,
    Second Phase LHC Collimators

55
Measurements
  • Measure
  • time
  • water flow
  • water pressure in
  • water pressure out
  • water temp in
  • water temp out
  • power supply voltage x2
  • power supply current x2
  • capacitive distance sensors x3
  • thermocouples x22
  • 37 parameters in total

56
Results consistent with ANSYS Simulations
  • Total Sagita 112 microns
  • ANSYS Simulation predicts 100 microns

57
Upstream end vertical section

Lundgren
Jaw
Geneva Mechanism
Worm Gear
Shaft
1-2mm Gap
Water Cooling Channel
U-Joint Axle
Support Bearings
Diaphragm
58
RF Trapped Modes studies
  • Studies have begun on looking into trapped modes
    in our collimator design
  • Many cavities and crevices, hour-glass shape
  • Will RF leak out into chamber behind jaws?
  • Cause wakefields effecting beam?
  • Chamber heating? Melt RF contacts?
  • Studies being carried out by Cho Ng and Liling
    Xiao with help by Karl Bane.
  • Omega3P uses the finite-element method and
    parallel processing. The finite-element method
    allows high-fidelity representation of complex
    geometries so that accurate calculations can be
    obtained. Parallel processing helps tackle
    large-scale problems and shorten computational
    time.

Model of collimator in Omega3P with jaws fully
inserted
Beam path
59
RF Contact Measurements Setup
Test critical RF contact resistance. First
results with silver coated fingers 0.6 mOhm.
59
60
RF Contact Measurements Setup
Test critical RF contacts. work proceeding...
Results by EPAC08
60
61
Vacuum tank, jaw positioning mechanism and
support base derived from CERN Phase I
62
Contact Resistance Experimental Setup
63
T-980 GOALS
  • Measure channeled, volume-reflected and scattered
    beams as well as beam losses (radiation levels)
    downstream of the crystal setup and verify
    simulations.
  • Demonstrate reproducible beam loss reduction in
    the B0 and D0 and verify simulations, aiming at a
    routine use of the crystal based collimation in
    the Tevatron stores.
  • Test and confirm fundamental models of
    single-turn and multi-turn dynamics with
    crystals.
  • Develop optimal crystal/goniometer/instrumentation
    system for one- and two-plane collimation
    exploring and exploiting novel crystal
    technologies and newly understood phenomenon,
    volume reflection.
  • All of the above in conjunction with the CRYSTAL
    experiment at CERN SPS, aiming at a Phase II
    crystal-based collimation system for the LHC
    (performance, reduced impedance and heavy-ion
    option)

64
Crystal
  • Strip crystal and goniometer removed from the
    tunnel in December 2007 after several
    unsuccessful attempts during 2007 of EOS studies
    in the Tevatron. Crystal is too radioactive to
    perform its characterization.
  • The O-shaped crystal of successful studies of
    2005-2006 was shipped to Europe in January 2008
    for its analysis.
  • Analysis with 2-MeV He ions performed by V.
    Guidi at Ferrara, INFN, has shown that quality of
    the surface of the O-shaped crystal is very good,
    and it needs no treatment.
  • X-ray measurements of bending angle and miscut
    angle with 5 accuracy performed by Yu. Ivanov,
    PNPI.
  • The crystal is back at Fermilab.

Successful 0.44mrad O-shaped crystal of
2005-2006 studies
Unsuccessful 0.15mrad strip crystal of 2007
studies
65
Goniometer Design Changes Implemented (1)
  • Swing Motion
  • The inchworm motor has been eliminated, and
    replaced with a linear actuator. The stepping
    motor and LVDT are now external to the vacuum.
    The linear actuator provides .025 linear travel
    per revolution 200 steps. The actuator has a
    vernier scale with 25 marks, each indicating
    .001 linear movement at the outboard end of the
    swing arm.
  • The actuator normally moves 200 steps per
    revolution, but the control provides for 1600
    microsteps per revolution 000015625 per
    microstep.
  • The swing arm length from the actuator to the
    pivot point is 11.471 tan-1 (.000015625/11.471)
    .000078 degrees .000001362 radians 1
    microstep 1.362 urad of swing motion of the
    crystal 10 microsteps 13.62 urad
  • The LVDT is able to read .000025 linear motion
    tan-1 (.000025/11.471) 2.179 urad motion read
    by the LVDT.
  • A movement of 50 steps read a change of 54 mVolts
    on the LVDT and 3.1 marks on the vernier scale.
    Total range of swing motion is /- 2 degrees or
    /- 35 milliradians from the nominal center of
    motion, i.e. with the crystal face parallel to
    the beam line. There is a visual position
    indicator in line with the LVDT.
  • A frictional problem with the swing arm dragging
    on the stationary arm has been repaired.
  • A vibrational problem with the crystal target
    holder has been solved with locking screws.
  • Motion of the swing arm can now be observed
    through a glass viewport on the top.

R. Reilly, A. Legan
66
Goniometer Design Changes Implemented (2)
  • Horizontal Motion
  • The new linear slide has a threaded lead-screw
    drive, as opposed to the previous ball-screw
    drive. This was changed to prevent motion due to
    vacuum loading, and the motor shaft brake is now
    unnecessary and has been eliminated. The ratio is
    .020 per single revolution or 400 steps.
  • 400 steps .020 20,000 steps 1.00 50
    revs 1 step .00005 10 steps .0005 20
    steps .001
  • Total available motion 2 100 revs 40,000
    steps.
  • A movement of 1000 steps read a change of 480
    mVolts on the LVDT.
  • Total range of X motion has been set at 2 by
    limit switches, and the range of the LVDT is also
    2.
  • The fully inserted position (moving out from the
    Tevatron center) puts the face of the crystal
    approximately in the center of the 4 beam tube.
    Fully extracted (moving towards the Tevatron
    center) puts the face of the crystal at the edge
    of the 4 beam tube.

R. Reilly, A. Legan
Hardware is now under vacuum certification
67
Beam Instrumentation E1 Scintillation Counters

Hardware/Software is ready to go
68
Multi-Turn Simulations with 0.44-mrad O-shaped
Crystal

Total losses on E03 and F172 via channeling, VR
and MCS. Inversely proportional to Deans LE033
BLM with E03 out
Channeled beam loss on E03
Edge-scattered in E03 and F172, x 5
Loss at B0, x 140
All collimators are in working positions
TRA_CRY_AP Code received from I. Yazynin on May
27, 2008
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