Outgassing Database

Welcome to the Outgassing Database for High and Ultra-High Vacuum (HV and UHV) Experiments

This database aims to be a comprehensive repository of outgassing data from literature and vacuum laboratories, serving the whole community. Here we include a special section to report about potential contaminants of surfaces, crucial for ensuring the integrity and performance of sensitive optical equipment in large-scale research instruments like the ET project. The policy for data submission is described below and will be discussed among all participating labs, and revised accordingly.

About the Database : The European Gravitational Observatory (EGO), home to the Virgo interferometer in Europe, hosts this database.

Purpose : Our goal is to provide a centralized source of vacuum outgassing for materials, assemblies, and components used in UHV chambers. Additionally, we want to include any relevant surface quality measurement data to indicate the best materials fabrication and treatment processes. By contributing to and using this database, you help advance our collective understanding and capability in maintaining high-performance vacuum systems for cutting-edge research.

Data Submission Policy :

Policy to add data :

Registration : Write an email to vacuum@ego-gw.it to register. You will be given credentials to modify the Outgassing Database.
Literature-Referenced Data : Submissions should reference established literature.
Lab Measurements Data : Data from both ET collaboration and external laboratories are welcome, provided they come with a comprehensive explanatory report.
Report Template: A template for outgassing and surface quality test reports is available.

Database Guidelines :

Component Creation/Selection :

Choose Component from the list or create a new one by selecting '+'. Remember to save by clicking the save icon.
'Item' column : indicates briefly the component origin with a few keywords
'Manufacturer' column : indicates the component producer origin
'Main material' column : indicates the main material composition under study

Vacuum Measurements :

'Test procedure' column : indicate the test method used (Throughput method etc..)
Outgassing rates are generally expressed as N2 equivalents
Low Volatile Compound 'Hydrocarbon' (HC) detection includes all fragments > 44m/z.
Background values are subtracted, and level > 44m/z compounds are flagged as potential contaminants for optical surfaces at room temperature.
'Q_HC (level>44)' column : indicates the sum of outgassing rates for level > 44.
'Peaks N>44' column : List the most relevant peaks > 44 m/z.
'OTHERS' columns refers to gases that do not fit the HC definition, such as CO, CO2, CH4, O2, etc..
'Comments' columns refers to cleaning procedure used including pre-baking
'Units' column: indicates the measurement units used (Torr-L/(cm²-s) or mbar-L/(cm²-s) or Pa-m³/(m²-s) if mono-material or mbar-L/s if multi-material component)

Surface Quality Measurements :

Include a document link containing surface quality measurements (roughness, porosity, surface contamination), using any optical techniques like SEM, XPS, Raman, XRR etc..

Data Updates :

Data can be updated anytime
An 'History' icon in the Entry column allows to trace changes.

References: [1] Vacuum Procedures to Measure and Report Outgassing Rates, [2] Outgassing and Optical Contamination Template Report

Component

Vacuum measurements

Surface Quality measurements

Item

Main material

Manufacturer

Test procedure

Q_H2O @24h

Q_H20 @100H

Q_H20 @1000H

Q_H2

Q_N2+OTHERS @24h

Q_N2+OTHERS @100h

Q_HC (level>44)

Q_HC (peaks N>44) (m/z)

Units

Comments

Experiment

Reference document

Test procedure

Reference document

PTFE cable

PTFE tape + Copper

Axon-cable

throughtput method

2.61e-7

3.81e-8

1.70e-9

2.90e-8

4.23e-9

2.55e-12

mbar-L/s

Per meter of cable! No prebaking. Measured with 40m of cabling.

Virgo

Virgo Logbook Vacuum #223

Test Mass Large Coil

Aluminum frame, Copper insulated by Kapton

EGO

throughtput method

1.34e-4

2.92e-6

7.70e-6

3.72e-6

3.90e-7

7.30e-10

mbar-L/s

After pre-baking 66 hours at 120°C (chamber temperature).

Virgo

Virgo Logbook Vacuum #191

Titanium (ASTM Grade 2)

Ti (ASTM Gr. 2)

N.A.

throughtput method

1.50e-10

3.61e-11

3.61e-12

2.50e-14

mbar-L/(cm²-s)

Q_H2O : Q=Qo*t^-alpha, with Qo=1.3e-3(Pa L s-1 cm-2) and alpha=1

NIST: DOI: 10.1116/6.0000657

Date	Done by	Modification
31-03-2025	sentenac	Comment changed from: Qo=1.3e-3(Pa L s-1 cm-2) and alpha=1
31-03-2025	sentenac	Comment changed from:
25-03-2025	gargiulo	Sample preparation highlights changed from:
25-03-2025	gargiulo	Units changed from:
18-10-2024	gargiulo	Notes changed from: Q_H2O : Q=Qo*t^-alpha, with Qo=1.3e-3(Pa L s-1 cm-2) and alpha=1
25-11-2022	gargiulo	Notes changed from: xxx Reference text changed from: xxx

Baffle PCB#10-21

Pyralux AP

IFAE

throughtput method

1.03e-8

5.43e-9

1.94e-9

3.31e-11

5.00e-13

mbar-L/s

Virgo

IMC Instrumented Baffle, Ref. IFAE-PCB#10-21

Date	Done by	Modification
25-03-2025	gargiulo	Experiment changed from: Units changed from:
25-11-2022	gargiulo	Optical losses (ppm) changed from: 0.5

Al EN AW-6061

N.A.

throughtput method

4.86e-10

1.17e-10

1.17e-11

5.50e-14

mbar-L/(cm²-s)

Q_H2O : Q=Qo*t^-alpha, with Qo=4.2e-3(Pa L s-1 cm-2) and alpha=1

NIST: DOI: 10.1116/6.0000657

Date	Done by	Modification
01-04-2025	gargiulo	Units changed from:
31-03-2025	sentenac	Comment changed from:
18-10-2024	gargiulo	Notes changed from: Q_H2O : Q=Qo*t^-alpha, with Qo=4.2e-3(Pa L s-1 cm-2) and alpha=1

AISI 316L Vacuum Fired

AISI 316L

N.A.

throughtput method

8.64e-11

2.43e-11

3.21e-12

5.10e-14

mbar-L/(cm²-s)

Vacuum fire process: 950°C for 24h Q_H2O : Q=Qo*t^-alpha, with Qo=3.30e-4(Pa L s-1 cm-2) and alpha=0.91

NIST: DOI: 10.1116/6.0000657

Date	Done by	Modification
01-04-2025	gargiulo	Units changed from:
31-03-2025	sentenac	Comment changed from:
18-10-2024	gargiulo	Notes changed from: Vacuum fire process: 950°C for 24h Q_H2O : Q=Qo*t^-alpha, with Qo=3.30e-4(Pa L s-1 cm-2) and alpha=0.91
28-09-2022	gargiulo	Main material changed from: AISI 316L Vacuum Fired

AISI 316L

N.A.

throughtput method

1.20e-10

3.09e-11

3.48e-12

1.00e-12

mbar-L/(cm²-s)

Q_H2 : conventional outgassing rate Q_H2O : Q=Qo*t^-alpha, with Qo=7.25e-4(Pa L s-1 cm-2) and alpha=0.95

NIST: DOI: 10.1116/6.0000657

Date	Done by	Modification
01-04-2025	gargiulo	Units changed from:
31-03-2025	sentenac	Comment changed from:
18-10-2024	gargiulo	Notes changed from: Q_H2 : conventional outgassing rate Q_H2O : Q=Qo*t^-alpha, with Qo=7.25e-4(Pa L s-1 cm-2) and alpha=0.95

AISI 304L

N.A.

throughtput method

2.68e-10

4.19e-11

2.10e-12

1.00e-12

mbar-L/(cm²-s)

Q_H2 : conventional outgassing rate Q_H2O : Q=Qo*t^-alpha, with Qo=7.00e-2(Pa L s-1 cm-2) and alpha=1.3

NIST: DOI: 10.1116/6.0000657

Date	Done by	Modification
01-04-2025	gargiulo	Units changed from:
31-03-2025	sentenac	Comment changed from:
18-10-2024	gargiulo	Notes changed from: Q_H2 : conventional outgassing rate Q_H2O : Q=Qo*t^-alpha, with Qo=7.00e-2(Pa L s-1 cm-2) and alpha=1.3
28-09-2022	gargiulo	Vacuum measurement: Q_H2O @100h changed from: 0.000000000419 Notes changed from: ---

RMC_coil_001

Kapton / PEEK

EGO

Rate of Rise

6.20e-8

2.80e-8

9.30e-9

8.00e-10

mbar-L/s

Pre-baking hours: 147

ISB-VC-0039

Date	Done by	Modification
01-04-2025	gargiulo	Units changed from:
31-03-2025	sentenac	Test procedure changed from: throughtput method
31-03-2025	sentenac	Comment changed from:
01-02-2022	gargiulo	Pre-baking hours changed from: 147
20-10-2021	gargiulo	Test procedure changed from: Rate of Rise