GTSnext

1. GTSnext About GTSnext Website of collaboration EU proposal GTSnext http://www.gtsnext.eu/index.php?contentid=3 http://www.earthtime-eu.eu/OpenDocuments/GTSnext.pdf

2. People involved Vrije Universiteit Amsterdam – project staff Faculty of Earth and Life Sciences scientist in charge Dr. Leah Morgan Leah.morgan@falw.vu.nl Ing. Onno Postma Faculty of Earth and Life Sciences system engineering Onno.Postma@falw.vu.nl Rob Stoevelaar mechanical workshop R.Stoevelaar@beta.vu.nl mechanical workshop DJ.van.Iperen@beta.vu.nl Dick van Iperen Wim van der Plas electronics department Wim.van.derPlas@beta.vu.nl GTSNext science collaborators Dr. Jan Wijbrans Vrije Universiteit - Faculty of Earth and Life Sciences Jan.Wijbrans@falw.vu.nl Klaudia.Kuiper@falw.vu.nl Dr. Klaudia Kuiper Vrije Universiteit - Faculty of Earth and Life Sciences Dr. Darren Mark Scottish Universities Environmental Research Centre (SUERC) D.Mark@suerc.gla.ac.uk igor@geo.unibe.ch Dr. Igor Villa University of Bern

3. Process scheme File: system_map.pdf

4. Process description The system will act to store, clean, and quantitatively measure high purity 40Ar.  The source gas will be attached to the system via valve 1.  By taking a 10mL pipette from here, we will store and clean a smaller quantity of this gas in the getter region (parts #15,16,25).  Another 10mL pipette will allow a fraction of that gas into the main reservoir/pipette region, which will have well calibrated volumes and a pressure gauge attached.  After measuring the pressure of the gas at ~1 torr, the pressure gauge valve (#22) will be closed, and then two expansions of gas trapped in the pipette will decrease the pressure to workable levels.  Then, 2mL pipette shots of acceptable levels for measurement in mass spectrometers will be taken from the reservoir to calibrate the mass spectrometer.

5. Argon reservoir: set up

6. Argon reservoir: description To be written. Relates to preceding reservoir figure

7. Pressure gauge MKS 690A ; 0 – 1 torr ; part #19 high accuracy Baratrons.pdf A note about high accuracy capacitive pressure gauges High accuracy MKS pressure gauges general information 600hi_ac-1_MKS.pdf Pressure gauge MKS type 690A01TRA manual MKS_690_manual.pdf Relative error of MKS 690A pressure gauge Some specifications Full scale: 1 torr Output voltage : 0-10 Volts Temperature regulated at 45 °C Warm up time before adjusting zero: 4 hours minimum Transducer must be powered continuously. Highest pressure for proper zero adjust: 10-6 torr Materials exposed to gasses: Inconel, stainless steel Accuracy of reading : 0.05 % Resolution 10-5 of full scale 1 torr Temperature coefficients Zero: 4×10-6 of full scale/°C Span: 20×10-6 of span/°C The unit must be mounted horizontally. AD converter Accuracy full : 0.05% × 10 V = 0.5 mV 16 bit AD converter: 10 V / 216-1 = 0.3 mV

8. Swagelok 4BG valves + VCR connectors: parts # 9,10,22 Pipette construction using 4BG valves parts #9,10 Valve type specification: SS-4BG-VCRVD-5C Valve body: male VCR connectors, solid body (no Argon welds), 316SS/A479 Stem + bellow + weld ring: 316 SS/A479, 2 Argon welds between bottom and top plates Vacuum stem tip adaptor: copper with vented slot Gasket: Silver-plated 316 SS/A580 Volume of valve between valve ends and stem tip: 0.5 mL 4bg_Swagelok.pdf 4BG valves documentation VCR components 316L VAR stainless steel SEMI F20‑0305 High-Purity VCR_Swagelok.pdf VCR documentation

9. VAT manual valves, parts # 7,8,11 • VAT manual valves series 57 • -DN16 mm • -Conflat seals • -Valve body, mechanism AISI 304L (1.4306), AISI 316L (1.4435) • Bellows AISI 316L (1.4404) • Cycles until first service 10 000 • Heating and cooling rate ≤ 60°C h-1 • Leak rate: body, valve seat < 1 · 10-10 mbar Is-1 • Seal: bonnet, plate metal • -Valve body ≤ 450°C open / ≤ 350°C closed • Manual actuator (hex-head) DN 16 ≤ 450°C • -More info in VAT catalogue: Catalog2012_VAT.pdf Valve volume Reihe 57 Volumenberechnung.pdf Cut through of VAT manual valve

10. Components: steel general information General information on steel quality From scrap metal to vacuum components …., how is metal processed to give the characteristics required for vacuum processes?... Design considerations in the use of stainless steel for vacuum and cryogenic equipment. …..The properties making austenitic stainless steel a preferred material for the construction of high vacuum equipment are reviewed. …. Outgassing of vacuum materials …. it presents outgassing rates for various materials in tabulated form…… scrapmetal.PDF steel_ESR_CERN.pdf outgassing.pdf

11. Insert: part #18 The insert is made of 316LN vacuum fired stainless steel and has a well known volume, approximately 200 mL

12. Visit Nederlands Meet Instituut- NMI 20 april 2010 Onno and Leah visited NMI in Delft Contact person: mr. van Veghel Cylinder The slug design was presented The design appeared to be measurable by NMI Achieved accuracy in measuring is < 1 mm Diameter will be measured at several points along the length axis of the cylinder The diameter form error of the cylinder diameter will be measured along the full length of the cylinder The round offs at the cylinder ends of R=0.5 mm can be measured. NMI however has to find an appropriate measuring procedure but they are optimistic. The parallelism of the end faces will be measured with the stated accuracy of < 1 mm . The form error of the end faces will be measured . NMI will assist us in calculating the confidence interval for the slug total volume The indicated surface roughness of 0.025 mm is sufficient with respect to the accuracy we want to achieve. Sphere We also discussed the possibility of using multiple spheres instead of a cylinder. He was very positive about using spheres especially because the form error of the sphere (roundness or sphericity) is easier to measure with the high accuracy we intend to achieve. Spheres are produced in mass quantities at precision grades and are therefore much cheaper than a specialty cylinder.

13. Argon source gas Source of Argon test gas : Oak Ridge National Laboratory Composition of Argon test gas Lee_atmAr.GCA.2006.pdf Full description of Oak Ridge Argon test gas preparation and properties Bottle with CF16 flange (scale in inches)