Quickcal 4 Jun 1999

> Minutes for quick cal meeting 11-00, 4 Jun 1999
> Present B.Kennedy, R.M.Brown, P.S.Flower
> 
> BWK  
> Reported on developments in designs of the spacing between supermodules in
> the end caps.
> The engineers want to go to a parallel spacing rather than a tapered one.
> Their proposal is a 0.5 mm spacing with a 0.5 mm tolerance. This would
> result in parallel spacings of between 0.5 and 1.0 mm.
> BWK is cross checking the new calculations of block positions.
> 
> BWK also reported on his latest studies to determine the best way of
> matching a restricted number of supermodule shapes to the required solid
> angle of the end cap. 
> The latest models he reported on were:
> 1. TDR aperture - 3 cm and only full supermodules
> 2. 	TDR aperture - 6 cm and only full supermodules.
> 
> BWK had also reworked his graphical presentation to highlight differences
> between endcap arrangements.
> Initial indications are that the fall off in the precision of energy
> measurement with decreasing aperture is small but the effect extends to
> higher eta values. To get a better understanding he is going to extend
> modelling to higher values of eta 
> 
> Next week
> Further calculations on supermodule positions in collaboration with Len
> Denton
> Extend energy calculations to higher eta.
> Interview new sandwich student Monday
> 
> PSF 
> Presented results from a set of radiation damage measurements on resins he
> had carried out at Brunel. 
> 4 samples, had been exposed to approximately 0.5 M rad by irradiation with
> a 60Co source for 8 days. More work was needed to understand properly the
> radiation dose and express the change as absorbance.
> Damage was estimated by measuring the induced the change in optical
> transmission
> Sample
> Damage     
> Plain glass,
> Significant
> plain quartz,
> None
> a thin layer ( 0.066 mm)of Dow 3145 between quartz,         None
> a thick layer (1.155 mm) of Dow 3145 between quartz        Slight
> It was concluded that glass could not be used for radiation damage tests,
> but quartz was fine.
> The damage to the resin was slight and in the 300 to 400 nm region. 
> Variations in the base line of the spectrophotometer meant that it was not
> possible to determine the damage to a thin layer of resin.
> 
> PSF also reported that he had worked at least 2 hours each day on his
> thesis
> 
> Next week
> RMB suggested that PSF circulate a provisional note on radiation damage to
> Dow 3145 resin before carrying out a more detailed analysis.
> 
> RMB
> Most of week taken up with administrative issues and meetings.
> Reported on steering committee meeting highlighting current tracker
> issues.
> 
> 
> P.S.Flower
> 8 June 1999
>