Cryo-target wall contamination

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The normalized yield is equal to Ngood/Q/density. Here I neglected the density of the 3He gas.


Kinematic 5.2

Target window thickness Total charge # of good evts
upstream downstream
He3 0.0274 cm 0.0328 cm 6.92E+8 253254
Dummy 0.1581 cm 0.1585 cm 2.16E+8 3588

Result: An estimate of 2186 events wall events remains within the cut ==> Contamination is less than 1%.


He3 5.2 all.gif

Dummy 5.2 all.gif


Kinematic 6.5

Target window thickness Total charge # of good evts
upstream downstream
He3 0.0274 cm 0.0328 cm 1.045E+9 110050
Dummy 0.1581 cm 0.1585 cm 1.316E+7 294

Result: An estimate of 4439 events wall events remains within the cut ==> Contamination is 4%.


He3 6.5 all.gif

Dummy 6.5 all.gif


  • With the full statistic collected till run 4039 (the last plot has the dummy histo multiply by 30) and the following cuts were applied to 3He and dummy runs:
 -  sprintf(cutnom,"L.tr.n==1 && DBB.edtpr[0]==0 && (DBB.evtypebits>>3)&1");
 -  sprintf(cutdum_y,"abs(L.tr.tg_y-0.0025)<0.030"); or sprintf(cuthe_y,"abs(L.tr.tg_y)<0.030");
 -  sprintf(cutphi,"abs(L.tr.tg_ph)<0.020");
 -  sprintf(cuttheta,"abs(L.tr.tg_th)<0.040");
 -  sprintf(cutcer,"L.cer.asum_c>300 && L.cer.asum_c<8000");
 -  sprintf(cutcalo,"(L.prl1.asum_c+L.prl2.asum_c)>1000");
 -  sprintf(cutdum_all,"%s && %s && %s && %s && %s && %s", cutnom, cutdum_y, cutphi, cuttheta, cutcer, cutcalo); or sprintf(cuthe_all,"%s && %s && %s && %s && %s && %s", cutnom, cuthe_y, cutphi, cuttheta, cutcer, cutcalo);

Dummycont 6.5.gif