Virtual Alignment alignment technique for no CR exposure or very low density case Satoru Takahashi Nagoya Univ.

Introduction Film deformation at transformation and at brick seems same within several micron. –O. Sato reported at last meeting (GS Nov./2007) instead of me. “Virtual alignment” will perform with several micron accuracy. –“Virtual alignment“ is used X-ray mark for global correction CR at transportation for local correction. Tried “virtual alignment” correction : rotation, shrink, shift

Film arrangement film lead film Transportation Brick Using 2 films, we can get deformation map at transportation and brick respectively.

Deformation map between film micron

Deformation map between film 1 – 50micron

RMSy=1.4micron RMSx=2.4micron difference (transportation - brick) (film 1 – 2) 10micron Deformation seems conserving between transportation and brick.

Virtual alignment ･ Used several films of brick:36565 exposed CR ･ Scanned full area ･ Important to read X-ray mark accurately for accurate alignment –Trying now ･ Instead of X-ray mark, used tracks at area near the X-ray mark ･ Global correction is used tracks at area near the X-ray mark. ･ Local correction is used tracks at transportation ･ After virtual alignment, I check position difference using brick tracks. X-ray mark x y 1cm Lead d film

Position difference offset[micron] = ( -13.2, 2.2 ) RMS[micron] = ( 5.8, 5.8 ) Position difference have offset. [micron] dxdy plate

Prospect for offset If films curl at transportation offset appear. CR transportation after scanning If curl effect contribute offset should be had same value.

Offset for several combinations film1 – film2 offset dx[micron] offset dy[micron] 25 – – ｰ Offset is same within several micron.

pl25-26 pl26-27 pl27-28 position x – position difference x distribution full area This is having information of curl. shape is same analyzing now position difference x[micron] position x

Handling of curl effect ･ At only first connection, allow several tens micron to get offset value. ･ After getting offset value, can be predicted several micron accuracy. ･ So curl effect is no problem. Lead film

Summary Deformation seems conserving between transportation and brick Virtual alignment will perform several micron accuracy. In this trial, position difference have offset after virtual alignment. –I assume the offset is caused curl effect Curl effect is no problem –Offset can be gotten by first connection. Virtual alignment will be worked.

After this Read X-ray mark accurately for global correction Evaluate virtual alignment systematically Complete virtual alignment