Straw manufacturing current status T.Enik, S.Shkarovskiy, I.Polenkevich,Yu.Potrebenikov

“Raw” straw 139 straws (2700 mm) are ready. 46 ring samples from the beginning of straws (5 mm width) and 22 ones from the end of straws were broken off on base material ~ 70 straws from one tape roll “raw” straws per day Example of a bar code 07/02/11Yu.Potrebenikov2

“Raw” straw quality A piece of the straw #3 remain alive at 7 Atm overpressure more then 10 days (end plug is formed by thermo glue) Blue – start of the straw; Red – end of the straw A piece of the straw #14 (~40 cm) remain Alive at 9 Atm overpressure more than 1 min; 1,5 mm elongation after break 07/02/11Yu.Potrebenikov3 We propose min=3 mm

“Raw” straw quality Blue – start of the straw; Red – end of the straw 07/02/11Yu.Potrebenikov4 Min=4 kg Min=3 mm

Last configuration of the welding machine Thermo stabilization zone near welding point New visualization: 2 microscope Visual control Frequency control Automatic (computer) control 07/02/11Yu.Potrebenikov5

Thermo stabilization of the welding area General cooling Local sonotrode cooling ( air blowing by thin injector ) Small air overpressure into straw ( diameter stabilization ) 07/02/11Yu.Potrebenikov6

Straw quality before and after modification of the welding machine Straw #83: only 5 rings from 26 broken along the seam 07/02/11Yu.Potrebenikov7

Straw diameter distribution Blue – star of the straw; Red – end of the straw More than 95% straws have the same diameter 9.77 mm (20 microns precision) 07/02/11Yu.Potrebenikov8

Straw leakage Straw and PVC tube with 4 Atm He overpressure in cooled boiled water 07/02/11Yu.Potrebenikov9

Straw plugging and connection for long term overpressure test 07/02/11Yu.Potrebenikov10

Conclusion and plans 1.After modification of the welding machine straw quality seams good 2.Long term overpressure test and leakage test are under preparation 3.It is necessary to produce more than 500 straw till the end of February to deliver their to CERN at the beginning of March 4.It is necessary to define minimal straw quality test before sending straws to CERN and minimal straw quality test at CERN before their installation into Module-0 07/02/11Yu.Potrebenikov11