target status report lara howlett university of sheffield

Target Status ReportTarget Status Report

Lara HowlettLara Howlett

University of SheffieldUniversity of Sheffield

Lara Howlett – University of Sheffield Frascati, June 2005

ContentsContents

A look at the specsA look at the specs Reminder of Prototype plansReminder of Prototype plans Meetings with ISIS engineersMeetings with ISIS engineers Testbeam plansTestbeam plans Status of electronics, readout and Status of electronics, readout and

radiation studiesradiation studies Plans / TimescalePlans / Timescale


Updated SpecsUpdated Specs

Frequency 1-3 Hz. Higher may be Frequency 1-3 Hz. Higher may be possible but we may be limited by possible but we may be limited by heatingheating

Target will dip into the beam by 5-Target will dip into the beam by 5-10mm10mm

Only the intersection of the beam in Only the intersection of the beam in the last 1ms is usefulthe last 1ms is useful

We wish to intersect as little beam that We wish to intersect as little beam that is not useful as possibleis not useful as possible


Updated SpecsUpdated SpecsHigher resolution

45

50

55

60

65

70

75

80

0 5 10 15 20 25 30

T(ms)

R (

mm

)

beam

target

4.4mm

2.05ms


Updated SpecsUpdated Specs1000 g

40

45

50

55

60

65

70

75

80

85

0 5 10 15 20 25 30

T (ms)

R (

mm

)

beam

target

7.4mm

2.75ms


Updated specsUpdated specs(3)

20

30

40

50

60

70

80

90

100

-15 -10 -5 0 5 10 15 20 25 30

T (ms)

R (

mm

)

beam

target

9.8mm

3.35ms


Overview of PrototypeOverview of Prototype

The prototype is currently being The prototype is currently being built and is expected to be ready built and is expected to be ready by the end of the monthby the end of the month

The design consists of a a The design consists of a a magnetic shuttle to which the magnetic shuttle to which the target rod is attachedtarget rod is attached

This sits inside a series of coils This sits inside a series of coils which are driven in 3 phasewhich are driven in 3 phase


PrototypePrototype

~8 cm


Target MechanismTarget Mechanism


Meetings with ISISMeetings with ISIS

Several very useful meetings have taken Several very useful meetings have taken place with engineers from ISISplace with engineers from ISIS

These have been very useful for These have been very useful for beginning to look atbeginning to look at– Safety issuesSafety issues– Vacuum issuesVacuum issues– How the target mechanism will be mountedHow the target mechanism will be mounted

A first set of engineering drawings have A first set of engineering drawings have also been produced by Stephanie Yangalso been produced by Stephanie Yang


OutcomesOutcomes

The diaphragm springs will most likely be The diaphragm springs will most likely be replaced by ceramic bearingsreplaced by ceramic bearings

The target will be mounted on a replacement The target will be mounted on a replacement for the current A frame to reduce vibrations for the current A frame to reduce vibrations transmitted to the beam pipe by the targettransmitted to the beam pipe by the target

The possibility of replacing the inductive The possibility of replacing the inductive measurement system with an optical system measurement system with an optical system is under investigationis under investigation

The possibility of mounting the target using The possibility of mounting the target using nested bellows with a gate valve which would nested bellows with a gate valve which would allow the target to be completely removed allow the target to be completely removed from the beam in case of failure is being from the beam in case of failure is being investigatedinvestigated


SchematicSchematic


Status of ElectronicsStatus of Electronics

The electronics consists of two The electronics consists of two separate integrated circuitsseparate integrated circuits– Control logicControl logic– Current controllerCurrent controller


Control LogicControl Logic

Position Decoder/Switching

Sequencer

Optical Isolators

Hex-Bridge Electronic 3 Phase Motor Switch (6

MOSFETS)Hall Switches

(Position Sensors)

ACTUATOR


Current ControllerCurrent Controller

Hex-Bridge Electronic 3 Phase Motor Switch (6

MOSFETS)

Position Decoder/Switching

Sequencer

Active Current Control

PWM @ 19.5

kHz

Current Transducer

User Set Current (8-

Bit Resolution)


Future PlansFuture Plans

To test this prototype circuitry with the actuator in order to ascertain its performance

Development of a quadrature position sensing system (to replace the hall switches) – This will allow greater control of the switching due to improved position information.

To develop an interface that will allow the electronics to be controlled via a PC


Radiation StudiesRadiation Studies

Simulations of radiation levels Simulations of radiation levels have continued have continued

These now include the geometry These now include the geometry of the target mechanismof the target mechanism

Radiation levels in the magnet Radiation levels in the magnet are extremely highare extremely high


Radiation studiesRadiation studies

Units :Grays/year/Unit Density


Status of ReadoutStatus of Readout Problems with the readout board were Problems with the readout board were

experienced which caused jumps in experienced which caused jumps in the counts which were read outthe counts which were read out

After long correspondance with the After long correspondance with the company who provided the board, and company who provided the board, and returning the board for tests twice the returning the board for tests twice the problem has been resolvedproblem has been resolved

The readout system will therefore be The readout system will therefore be ready to be used with the new ready to be used with the new prototype when it arrivesprototype when it arrives

Sheffield will have a summer student Sheffield will have a summer student who will be working on this in the who will be working on this in the coming monthscoming months


Test Beam PlansTest Beam Plans

There are plans to have the prototype There are plans to have the prototype ready for a test operation by Decemberready for a test operation by December

This would involve intersecting a few ISIS This would involve intersecting a few ISIS beam pulses when the machine starts up beam pulses when the machine starts up in Januaryin January

Measurements from the scintillators of Measurements from the scintillators of the Glasgow group will hopefully allow us the Glasgow group will hopefully allow us to gain a better understanding of how far to gain a better understanding of how far into the beam we need to go and how into the beam we need to go and how the beam profile changes with distancethe beam profile changes with distance


Backup plansBackup plans

In parallel with the work In parallel with the work described two ‘backup’ plans are described two ‘backup’ plans are being investigated in the being investigated in the backgroundbackground– The use of a lever to move the The use of a lever to move the

actuator away from the targetactuator away from the target– The use of a cam to provide the The use of a cam to provide the

motionmotion


LeverLever

Despite the hope that a lever would provide Despite the hope that a lever would provide a mechanical advantage discussions with an a mechanical advantage discussions with an engineer indicate that because of the low engineer indicate that because of the low mass of the shuttle this is not possiblemass of the shuttle this is not possible

However the use of a lever would give the However the use of a lever would give the advantage of moving the electronics and advantage of moving the electronics and magnets away from the radiation if this is magnets away from the radiation if this is necessarynecessary

The other advantage of this arrangement is The other advantage of this arrangement is that the target mechanism is isolated from that the target mechanism is isolated from the ISIS vacuum eliminating any possible the ISIS vacuum eliminating any possible problems of contaminationproblems of contamination


CamCam

The idea of a cam has The idea of a cam has also been investigated also been investigated in the background so in the background so that in the instance that in the instance that the em design that the em design does not produce the does not produce the accelerations required accelerations required a backup plan is in a backup plan is in place. This would be place. This would be used in conjunction used in conjunction with a leverwith a lever


PlansPlans

Upcoming milestones:Upcoming milestones:– Prototype should be assembled and Prototype should be assembled and

ready for tests to begin mid Julyready for tests to begin mid July– Prototype should be sufficiently Prototype should be sufficiently

tested to put in the beam by tested to put in the beam by ChristmasChristmas

– Data from beam tests should be Data from beam tests should be used as input for final designused as input for final design


ConclusionsConclusions

Work towards the prototype is Work towards the prototype is progressing and we expect to start progressing and we expect to start tests in the coming weekstests in the coming weeks

Several successful meetings with ISIS Several successful meetings with ISIS engineers have taken place and these engineers have taken place and these have been extremely useful in have been extremely useful in progressing with the designprogressing with the design

Exactly how far we need to go into the Exactly how far we need to go into the beam has significant implications for beam has significant implications for the design, so we should pin this the design, so we should pin this number down as much as we cannumber down as much as we can

target status report lara howlett university of sheffield

Documents

little beam

updated specs4

updated specsfrequency