14/1/20097 January 2009 MICE CM23 - Harbin - Beamline Session 1

MICE Beamloss Data

Adam Dobbs

14/1/20097 January 2009 MICE CM23 - Harbin - Beamline Session 2

MICE Beam Loss Studies Overview

• Purpose – understand beam loss in ISIS due to MICE target

• Analogue ISIS beam loss signals (total ring loss, total sector 7 and 8 loss) readout by a MICE DAQ

• ISIS beam intensity, position and MICE target position signals also recorded by the DAQ

• DAQ operates at 100 kHz

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14/1/20097 January 2009 MICE CM23 - Harbin - Beamline Session 3

Raw Data

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14/1/20097 January 2009 MICE CM23 - Harbin - Beamline Session 4

Averaged Data

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MICE beamloss

ISIS at normal rep rate, 5 spills shown, MICE target dip on first spill

14/1/20097 January 2009 MICE CM23 - Harbin - Beamline Session 5

Averaged Data – reduced rep rate

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ISIS at reduced rep rate => No spills without target present so cannot subtract background!

14/1/20097 January 2009 MICE CM23 - Harbin - Beamline Session 6

Background-subtracted Data (not averaged)

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-used to make lookup table of target depth and beamloss for every actuation

14/1/20097 January 2009 MICE CM23 - Harbin - Beamline Session 7

Averaged and BG-subtracted

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Data set 15-12-08_07

14/1/20097 January 2009 MICE CM23 - Harbin - Beamline Session 8

Averaged and BG-subtracted

Electronics artefactPossible losses from target scraping beam at injection

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14/1/20097 January 2009 MICE CM23 - Harbin - Beamline Session 9

Target Depth Vs Time

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Data set 19-12-08_00-03

- maximum target depth of each actuation over period of a run (of order hours). Below is for the evening of the target failure on 19-12-08

14/1/20097 January 2009 MICE CM23 - Harbin - Beamline Session 10

Data set 15-12-08_00-01

Target Position Vs Beamloss: actual-from a typical run

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Depth(mm) =Grad*Depth(V)+OffGrad = 10.1737Off= 22.5089

1V -> 32.68mm,1.25V -> 35.23mm

14/1/20097 January 2009 MICE CM23 - Harbin - Beamline Session 118 January 2009 MICE Target Meeting 11

Data set 19-12-08_00-03

Target Position Vs Beamloss: actual-from a night of target failure on 19-12-08. Severely reduced beamloss

14/1/20097 January 2009 MICE CM23 - Harbin - Beamline Session 12

Zoomed

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Data set 19-12-08_00-03

Quantisation of data for target position – note scale

14/1/20097 January 2009 MICE CM23 - Harbin - Beamline Session 13

Further Zoomed

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Data set 19-12-08_00-03

A 2nd quantisation of data for target position at smaller scale. Possible causes are discrete ruler measures used by laser position system, and the digitisation process