Diamond based particle detectors for LHC machine protection

Diamond based particle detectors for LHC machine protection

analysis of data from Run 1 and detector characterization experiments

Oliver Stein TE-MPE, [email protected] 2

MotivationIntroduction- Ionisation Chamber Beam Loss Monitors (icBLM)- Diamond Beam Loss Monitors (dBLM)dBLM characterization- Analysis of LHC dBLM data from run 1- Specialised experiments with dBLMs at the BTF in Frascati, ItalyOutlookConclusion


The detection of beam losses is important for the safe operation of the LHC and its pre accelerator complex at CERN!

Beam losses are THE indicator for the existence of an (unacceptable) danger in the accelerators:- Beam instabilities- Orbit offsets- Equipment failures

The installed Beam Loss Monitors (BLM) are implemented in the Beam Interlock System Losses above the defined thresholds cause a beam dump!

Motivation


Ionization chambers (icBLM) are used as the standard BLM - N2 filled cylinder (1.1 bar)- 60 cm length- Parallel electrodes (0.5 cm)- 40µs time resolution (half turn of LHC beam)- More than 3600 icBLMs installed

Electrode setup inside an icBLM

Introduction >> Ionization Chamber BLM

icBLMs in IP6

icBLM


What happens within 40µs?New BLM type: diamond based BLMs (dBLM).- 1.5 ns rise time resolution (5 ns FWHM)- Large dynamic range (1 (30) – (1010?) MIPs)

Courtesy of M. Hempel

Courtesy of M. Hempel

50 ns

Introduction >> Diamond BLM

E


dBLM should detect fast beam losses during LHC operation and help to understand the underlying loss mechanisms.

- Abort gap monitoring- Stable beams- Ramp/squeeze- Injection- Extraction

Introduction >> Diamond BLM


14 dBLMs experimentally installed along the LHC.- Diamond type: pCVD (cividec) 10 mm x 10 mm, wire bonded (8@LHC)- Analysis of dBLM data lead to a better understanding of UFO-events

Special dBLMs designed for high particle fluncies were used during damage tests in HighRadMat.- Diamond type: pCVD (civdec) 5mm Ø, clipped

CMS and Atlas are using dBLMs for beam condition monitoring (BCM).

Introduction >> Current status


Making the dBLMs fully operational and improve their usability for Post Mortem checks! Additional diagnostics

Steps:- Better understanding of the detector

- Detector response (linearity)- Efficiency- Saturation limits- Detection limits

- Development of DAQ system

Florian Burkart, Oliver Stein, Daniel Wollmann

BI, Bernd Dehning et al.

Introduction >> Future plans


dBLM characterization

Analysis of LHC dBLM data from run 1Specialised experiments with dBLMs at the BTF in Frascati, Italy


- (re) analyzing dBLM data from 2011/2012- Using UFO events for showing linearity- First attempt to compare dBLM signal with icBLM signals from the same event

difficult because a lot of uncertainties affect the analysis

40 db -6 db20 dbDiamond

Scope channel 1 (C1)


40 db -6 db20 dbDiamond



Beam 1

Beam 2

Analysis of LHC dBLM data from run 1 >> detector response


Analysis of UFO signals- Taking data of different signal intensities- Integration of single bunch losses



Linear?



dBLM characterization

Analysis of LHC dBLM data from run 1Specialised experiments with dBLMs at the BTF in Frascati, Italy


Characterization of the diamond detectors in at the Beam Test Facility (BTF) at the INFN in Frascati, Italy.- Electron beam at 450 MeV- Adjustable intensity from 1-1010 particles per bunch- Repetition rate 50Hz

Experiments at the BTF >> Introduction

BTF


Goals:- Voltage scans at different electron intensities for measuring the charge collection

distance (CCD) of different diamond detectors (100µm and 500µm)- Response and LimitsBeam time from 14.10.-20.10.2013 (Collaboration with UA9, low intensities)- Detectors:

- 3 x 100µm (5 mm )- 2 x 500µm

Experiments at the BTF >> Introduction

E

E


Experiments at the BTF >> Experimental setup

Beam window Detector setup Rail on X-Z-Table

calorimeter

Oliver Stein TE-MPE, [email protected] 17electron beam

Detector holder



electron

beam

Detector/PCB

SMA signal cable

LEMO HV cable



Medipix installed after the pCVD (10 cm)Beam profiles for different intensities: 1000e, 1850e, 2200e

1000e 1850e 2250e

Integration: 10s Integration: 10s Integration: 100s

Fitting measured beam profiles with 2D-gaussian:

Experiments at the BTF >> Beam profile measurements

sx

sy


- Beam size increases with higher intensities- Beam position changes with different intensities- Influence on the measurements?

Measurement mx(mm)

Dmx(mm)

my(mm)

Dmx(mm)

sx(mm)

Dsx(mm)

sy(mm)

Dsy(mm)

1000 e 6.60 0.006 7.31 0.002 4.32 0.007 1.57 0.009

1850 e 8.11 0.008 7.54 0.002 5.59 0.012 1.62 0.010

2250 e 7.39 0.006 7.50 0.001 8.06 0.013 1.66 0.012

Experiments at the BTF >> Beam profile measurements

Measurement mx(mm)

Dmx(mm)

my(mm)

Dmx(mm)

sx(mm)

Dsx(mm)

sy(mm)

Dsy(mm)

1000 e 6.60 0.006 7.31 0.002 4.32 0.007 1.57 0.009

1850 e 8.11 0.008 7.54 0.002 5.59 0.012 1.62 0.010

2250 e 7.39 0.006 7.50 0.001 8.06 0.013 1.66 0.012

Measurement mx(mm)

Dmx(mm)

my(mm)

Dmx(mm)

sx(mm)

Dsx(mm)

sy(mm)

Dsy(mm)

1000 e 6.60 0.006 7.31 0.002 4.32 0.007 1.57 0.009

1850 e 8.11 0.008 7.54 0.002 5.59 0.012 1.62 0.010

2250 e 7.39 0.006 7.50 0.001 8.06 0.013 1.66 0.012

Measurement mx(mm)

Dmx(mm)

my(mm)

Dmx(mm)

sx(mm)

Dsx(mm)

sy(mm)

Dsy(mm)

1000 e 6.60 0.006 7.31 0.002 4.32 0.007 1.57 0.009

1850 e 8.11 0.008 7.54 0.002 5.59 0.012 1.62 0.010

2250 e 7.39 0.006 7.50 0.001 8.06 0.013 1.66 0.012


Experiments at the BTF >> dBLM measurements


- Large variance of the measured data- Which parameters cause these variances?

- Changing beam size between shots?- Changing beam position?- Variation of beam energy

30% 14%




Beam setup 1

Beam setup 2


Assumptions:- Gaussian shaped beam- Beam size:

- sx: 4.32 mm- sy: 1.57 mm

- Max. signal: 75.2 %

Experiments at the BTF >> data analysis/results

Sign

al


Sensitivity:- Intensity dependency- Variation of relative beam position- Variation of the beam size

Experiments at the BTF >> data analysis/results

Sign

al

2 0 1 0 0 1 0 2 0

1 5 1 0 50

5

1 0

1 5

in te ns i ty

signal

Sign

al


- Continue data analysis (LHC, Frascati)- Request for own high intensity beam time for finalising measurements- Preparation of experiment setup

- Improvement of beam diagnostics, beam size, intensity measurements- Stage system- DAQ optimization (speed, scans,…)

- Collaboration with BI for LHC-DAQ system

Outlook


Analysis of dBLM data from run1- Detector linearity shown

Experiments at BTF, Frascati- Detector setup is working- DAQ successfully tested - Data shows variation of detector and calorimeter signals- Measurements at different intensities (low intensities, up to 2000 electrons)- Voltage scans performed uncertainties have to be identified request for high intensity measurements improve beam diagnostics- Preparation/optimization of the experimental setup and DAQ

Analysis of data (LHC/BTF) will be continued

Conclusion


Thank You!Any Questions?

Diamond based particle detectors for LHC machine protection

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