Report of recent DSSD status R. Kiuchi (SNU) 2012/10/20 E07
Sci.PMT Cooling box DSSD SSD Final try of DSSD (2012July) Cosmic-ray ・ Cooling of DSSD by dry ice ・ For confirmation, set SSD between DSSD and scintillator ・ 3 sci. coincidence of cosmic-ray I have checked all events which have on hits on SSD(due to setting efficiency ~ 70%), but there is no clear hits on DSSD (after last E07 meeting)
Pedestal distribution & IV curve of cooling RMS became SSD level !
Miss-Line on DSSD Recently discovered by Watabe-san REPIC just repaired it. (only DSSD #1)
DSSD – photo II. Line route “GND2” ”GND1” +1.25V 0V0V
SSD – photo I. ### 比較のためにSSDの写真も撮ってみ た 糊がボンディング上にある ためDSSDの写真よりも 不鮮明
Line route SSD – Photo II. “GND2” “GND1” +1.25V 0V0V
Bias voltage and current Before repair After repair almost same
Pedestal Noise(RMS) distribution between 2 APV chips and 1 new APV chip
Comparison of RMS Bias vol. =0V Bias vol. =40V Bias vol. =80V Bias vol. =0V Bias vol. =80V before after
Summary ・ It seems depletion of sensor part itself has some problem. ・ For (my) confirmation, I am going to try cosmic-ray test. ・ Currently the performance is not good, and we should choose SSD.
DSSD – 写真 1 N側の APV25 チップへのボンディング 写真 ### DSSD”1” 中央部分
SSD – 写真2 下側のパッ ド 上側のパッ ド ・4箇所で半田付けされているに見 える ・2箇所で半田付けされているに見え る