CLOUD experiment

Duplissy Jonathan

Detector seminar, 2010 October 22nd

Layout of the talk

1) Introduction to atmospheric particle2) CLOUD chamber3) Detectors

1) Introduction

Indian monsoon & Cosmic rays9500 to 6500 years ago

Neff et al., Nature 411, 2001

North Atlantic ice rafted debris

Bond et al., Science 294, 2001

Aerosol definition

Definition of an aerosol:

Suspension of small (liquid or solid)

particles in a gas

Primary aerosol:

Directly emitted into the atmosphere

Secondary aerosol:

Formed into the atmosphere

(aerosol directly emitted into the atmosphere)

Sea spray Volcano ► Sulfates, dustMineral dust

Biomass burning ►OrganicsTraffic emissions ► Soot

Primary aerosol

Pollen: 10 - 100 μm

Diesel soot: ca. 0.1 μm Ammonium sulfate: ca. 0.1 μm

Sea salt: 0.2 - 10 μm Mineral dust: 0.2 - 10 μm

Primary aerosol example

Zhang et al, science 328, 2010

Secondary aerosolaerosol is formed in the atmosphere

Influence of the galactic cosmic ray via the ionization of the molecule?

Example of Nucleation in a

control enviroment

Observation of ions and nucleation

Hirsikko, ACPD 10, 2010

Radiative forcing

Figure adapted from IPCC report 2005, full figure available on IPCC report

An

thro

po

gen

icN

atu

ral

Leve

l of scie

ntific u

nd

erstan

din

g

Direct Aerosol effect

Scattering and absorption of solar radiation

Indirect aerosol effect

Large droplets Weak reflection

Shorter life-time (rain)

Small droplets

Strong reflection Longer life-time

Steven & Feingold, nature 461 ,2009

Effect of particles on clouds:Ship tracks

Ship tracks on the East Atlantic Aerosol particles emitted by ships (soot

particles with a high sulfur content) act

as cloud condensation nuclei and form

clouds and enhance cloud reflectivity

France

Spain

http://visibleearth.nasa.gov/

Effect of particles on clouds:Contrails

Aerosol composition

Jimenez et al, science 326, 2009

2) Chamber

Smog chamberEnvironmental chamberCloud chamber

Smog chamber principle

• Do a control experiment:

1) Inject gas inside a chamber

2) Start reaction by ozonolysis (adding Ozone) or photo-chemistry (switching the light)

3) Measure the gas evolution and particle formation

(compare to flow tube experiment, smog chamber has longer residence time)

Outdoor smog chamber

The University of North Carolina Outdoor Smog Chamber, U.S.A.in operation since 1971

Fox et al, science 1976

Euphore, Valencia, Spain, 1995. Size: 200 m3

Outdoor smog chamber

http://www.ceam.es/

Outdoor smog chamber

http://saphir.fz-juelich.de

Saphir, Jülich, Germany, 2000. Size: 270 m3

Outdoor smog chamber

Stockholm University outdoor smog chamber, in a boreal forest environment , 2010

Indoor smog chamber

PSI’s smog chamber, Villigen, Switzerland, 2002. Size: 27 m3

Kalberer et al, science, 2004;Metzger et al, PNAS, 2010

Indoor smog chamber

AIDA chamber

85 m3 aluminum chamberTemperature ranging from -90°C to +50°CPressure ranging from 0.1 to 1000hPa

AIDA chamber, Karlsruhe, Germany, 1997. Size: 85 m3

http://www.eurochamp.org/chambers/aida/

Location of CLOUD at CERN

CLOUD in PS-T11

28

PS East Hall, Building 157

T11 beam area (3.5 GeV/c)

CLOUD chamber

Gas supply: Air, water, traces

Fan

Fan

Chamber

Exhaust

~27 m³, cleanliness to the highest standards (stainless steel, ceramic)

CLOUD chamber

Gas supply: Air, water, traces

Detectors

Fan

Fan

Chamber

Exhaust

~27 m³, cleanliness to the highest standards (stainless steel, ceramic)

state-of-the-art detectors (gas phase, ions, particles)

CLOUD chamber

Gas supply: Air, water, traces

Detectors

Fan

Fan

UV light fiber

Chamber

Exhaust

~27 m³, cleanliness to the highest standards (stainless steel, ceramic)

state-of-the-art detectors (gas phase, ions, particles)

CLOUD chamber

Gas supply: Air, water, traces

Detectors

Fan

Fan

UV light fiber

Chamber

IONS

Exhaust

hodoscope

PS Beam3.5 Gev Pi+

~27 m³, cleanliness to the highest standards (stainless steel, ceramic)

state-of-the-art instruments (gas phase, ions, particles)

ions at different concentrations created from CERN PS beam

CLOUD chamber

Gas supply: Air, water, traces

Detectors

Fan

Fan

UV light fiber

Chamber

Exhaust

HV Field cage

HV Field cagehodoscope

PS Beam3.5 Gev Pi+

~27 m³, cleanliness to the highest standards (stainless steel, ceramic)

state-of-the-art instruments (gas phase, ions, particles)

ions at different concentrations created from CERN PS beam

natural ions can be removed by HV field cage (~1s lifetime)

CLOUD chamber

Gas supply: Air, water, traces

Detectors

Fan

Fan

UV light fiber

Chamber

Exhaust

HV Field cage

HV Field cagehodoscope

PS Beam3.5 Gev Pi+

Thermal unit

~27 m³, cleanliness to the highest standards (stainless steel, ceramic)

state-of-the-art instruments (gas phase, ions, particles)

ions at different concentrations created from CERN PS beam

natural ions can be removed by HV field cage (~1s lifetime)

excellent thermal stability (±0.01°C), temperatures from -25°C to 100°C

CLOUD Aerosol chamber

35

• 27 m3

• Pressure: Atmospheric ± 0.3 bar• Only metallic seals• Electropolished inner surfaces

UV are brought to the chambervia optic fiber

- Control of the UV intensity- No heat load from the light

Light system

Light system

UV seen from the bottom

2 * 30 kVolts

Field cage

Mixing Fans

Gas supply: Air, water, traces

Fan

Fan

Chamber

Exhaust

Two mixing fans

Mixing fan

41

CLOUD chamber Temperature

Gas supply: Air, water, traces

Fan

Fan

Chamber

Exhaust

excellent thermal stability (±0.01°C), temperature ranges from -25°C to 100°C

Detectors

Thermal unit

CLOUD isolation

Isolated feet

CLOUD isolation

Temperature stability

More than 40 temperature sensors around the chamber

Temperature stability

47

• Chamber walls & internal temperature stable to ~0.01oC over long periods

• No temperature change when UV lights turned on at 100%

• No T-induced nucleations were observed during entire campaign

UV on at 100%

Tinternal

3h 20min record

2.8oC

2.9oC

2.4oC

2.7oC

2.6oC

2.5oC

16 electropolished sampling probes

Sampling probes

CLOUD chamber

Air supply

• Ultra-pure air is made from the mixture of liquid nitrogen and liquid oxygen

• SO2 and other traces gas are in very clean gas mixture bottles

• Ozone is produced by UV light system

Humidification System

UV

CERN clean and demineralized water

Dry pure air

Air saturated with water to the CLOUD chamber

Temperature controlled

Permapure

Particle filter

Particle filter

Organic filter

Organic filter

Ionsfilter

Very clean water with less than 3 ppb of organic, but still too much…

CLOUD installation

February 2009

CLOUD installation

53Caillebotis #!&?... November 2009!

July 2009 September 2009

CLOUD ready for technicalrun in December 2009

54

CLOUD

Detectors brought by:• Austria (University of Innsbruck, University of Vienna)

• Finland (University of Helsinki, Finish Meteorological Institute, University of Eastern Finland)

• Germany (Goethe University of Frankfurt, IfT Leipzig)

• Portugal (University of Lisbon)

• Russia (Lebedev Physical Institute)

• Switzerland (Paul Scherrer Institute, CERN)

• United Kingdom (University of Leeds)

• USA (CALTEC)

3) Detectors

Mass Spectrometers

• Api-tof-MS (ions)

• PTR-tof-MS (Organic)

• CI-MS (H2SO4)

• PTR-MS (NH3)

Gas Detectors

• O3 analyzers

• SO2 analyzers

• NH3 analyzers

• DewPoint

Beam

• Hodoscope

Particles counters

• Nano-SMPS

• CCNC

• CPC battery

• PSM

Ions counters

• NAIS

• Gerdien

CLOUD collaboration

10 Marie Curie fellows5 more PhD students5 more master students30 seniors scientificsAll great CERN teams

Aerosols nucleation

PS Beam,Hodoscope

API-tof-MS, PTRMS (VOC)

CIMS DewPointNAIS, Gerdien

CPC, SMPS, Snapper, AMS

CCNC, HTDMA

AIS principle

Bigger size

IonsAir flow (60 l/min)

Electrometer

High voltage

The AIS measures the ions distribution

Time

Aerosol inlet

Negative column

Positive column

Main power source, 15V

output

Electrometers’ output

signal collectors

Stabilized voltage units

for analyzers

Electrometers 1 ( at top) to 21

Electrometers 22 (at top) to 42

Pictures from: A.I.S. manual

AIS principle

PTR-MS

H2O

H2O+

O+

H+

OH+

H3O+

H3O+

H3O+

H3O+

VOC

VOC•H+e–

H3O+

H3O+

H3O+

Proton transfer

reaction when

PA(VOC)>PA(H2O)

H3O+ + VOC → VOCH+ + H2O pseudo first-order kineticsk

tkOHi

VOCHi

1

)(

)( VOC

3

PTR-MS How does it work?

PTR Drift Tube TOF-MS

Pulser Detector

Inlet

System Description: PTR-TOFMS

Time of Flight

Sign

al

Aquisition

Timing

Identification:

• Peak Separation

• Exact Mass Measurement

• Isotopic Ratio

HR-ToF-AMS

Inlet

Heater

ToF Mass Spectrometer

Filament

V-Mode

W-Mode

DeCarlo et al., Anal Chem (2006)

High Resolution comparison

DeCarlo et al., Anal. Chem (2006)

Atmospheric Pressure Interface Time Of Flight mass spectrometer

reflector

detector

10-6 mbar

10-4 mbar

10-3 mbar

2 mbar

3-stage turbo

scroll500 l/min

1 mbar

1 mbar

API-TOF scheme

Condensation Particle Counter

Buthanol CPC principle

CPC detection efficiency

Differential mobility analyser (DMA)

SMPS

Neutralizer DMA CPC

Known equilibrium charged of the particle

Select one size of the particle

Count the number of particle

SMPS provides size distribution of the particles

Results: fireworks at CLOUD

Thank you

Acknowledgement

Funding:

- EC's Seventh Framework Programme (Marie Curie Initial Training Network "CLOUD - ITN")

- German Federal Ministry of Education and Research

- Swiss National Science Foundation

- Academy of Finland Center of Excellence

- CERN