Περίληψη:
Three Multiwire Proportional Chambers (MWPC) with high rate capability have been constructed for Fermi National Accelerator Laboratory experiment 705 (Charmonium and Direct Photon production by 7r± , P and p at 300 GeV/c) [1]. Each chamber, with a sensitive area of 308 cm2 consists of three anode planes, wound with 12.5 µm diameter gold-plated Tungsten/Rhenium wire, facing 25 µm graphite-coated kapton cathode planes at a distance of 3 mm. Wire spacing in two of the MWPC (PC-B1 and PC-B2) is 0.75 mm and 1.00 mm in the third one (PC-B3). After a few weeks of running on “Magic Gas” with a beam flux of up to ~ 107 particles/cm2sec, severe damage occurred to the graphite coating. All cathode planes were replaced by aluminized kapton, and the chambers worked successfully for the next 3 months until the end of the run, when a 10% efficiency drop was observed after a total accumulated charge of ~1 C/cm of sense wire. After the end of the run the chambers were disassembled and inspected. A white deposit with a characteristic “wire pattern” etched away from the Al coating was observed in the region of the beam spot. © 1989 IEEE
Συγγραφείς:
Conetti, S.
Kuzminski, J.
Marchionni, A.
Statrs, D.
Haire, M.
Rosati, M.
Simard, A.
Zioulas, G.
Arenton, M.
Cox, B.
Chen, T.Y.
Lai, K.W.
Yao, N.
Delchamps, S.
Mazur, P.O.
Murphy, C.T.
Rameika, R.
Smith, R.
Turkot, F.
Yang, W.
Etemadi, B.
Guffey, K.
Tucker, W.
Fortney, L.
Shen, Q.
Tesarek, R.
Turkington, T.
Ioannu, P.
Kourkoumelis, C.
Koutentakis, I.
Manousakis-Katsikakis, A.
Pramantiotis, T.
Resvanis, L.K.
Vassiliou, M.
Voulgaris, G.
Jenkins, C.M.
Jude, D.J.
Turnbull, L.
Wagoner, D.E.
Mao, H.
Wang, C.
Shen, C.H.
Zhang, N.
Zhang, X.
Rosen, J.
Spiegel, L.
Tzamarias, S.
