Beam test of Silicon-Tungsten Calorimeter Prototype 7th ACFA workshop, Taipei 2004/11/10 Youngdo Oh (Kyungpook National University) On behalf of Ewha womans University: S.J. Baek, H.J. Hyun, A.L. Jeong, S.W. Nam, I.H. Park, J. Yang Korea University: J.S. Kang, S.K. Park, J.H. Choi Kyungpook National University: Y.D. Oh, K.H. Han, D.H. Kim, J.S. Seo, U.C. Yang Seoul City University: I.K. Park Sungkyunkwan University: I.T. Yu, Y.P. Yu Yonsei University: B.S. Jang, S.H. Jeong, J.H. Kang, Y.J. Kwon I’d like to talk about silicon calrorimetr. Actually what I want to talk about is a sort of report on our experience on silicon production. Let me start with why si is considered and what to be considered, and I will show you our work on silicon for a space experiment. And finally a few words on remarks.

Beam test Condition Beam Test : Aug. 30 – Sep. 7 2004 SPS : 400GeV proton beam Beam interaction with a target (T2) Beam cycle length 18.0 sec. 4.8 sec spill length User controls test beam particle type, energy(10,20,30,50,80,100,150 GeV), focus, and the intensity Test beam energy accuracy +/- 0.3% Beam particle purity > 95%

Tungsten and mechanics Tungsten size : 65.5 mm X 57.5 mm ( ~ sensor size) purity : close to 99% ( Rm = 9mm) thick : 3.5 mm (= 1 X0)

Sensor and analog electronics The heritage from space experiment 1mm inactive gap between sensors Silicon Sensor 32 pixels in a layer 131mm X 115mm Analog Board Aluminum 1.5mm pcb structure 10 mm Tungsten 3.5 mm Aluminum 1.5 mm 15 mm Rt= a layer / tungsten = 15.0/3.5 = 4.8 (CALICE ~ 2) Eff. Rm = 9mm * (1 + Rt) = 52mm Total 20 layers = 20 X0, 30cm thick 19 layers of shower sampling

Assembly & Mechanic support Tungsten 1X = 35mm Rt= a layer / tungsten = 150/35 = 4.8 (CALICE ~ 2) Total 20 layers = 20X (a CALICE prototype.: 30 layers 30X)

Assembly

Beam Test Activity beam 1. Tunning time delay 2. Detector Alignment run 3. MIP calibration of all channels (no tungsten) 4. Data Run (20 layers) (electron 150,100,80 50,30,20,10 GeV hadron 150 GeV muon 150 GeV) 5. Data Run (10 layers) : to study transverse shower profile beam

Monitoring data & alignment Detector alignment Data monitor : online, offline

Data Summary (50GB) Beam Beam Energy (GeV) files Etc 4x4x20 Muon 150 23 TD Check Electron 50 33 TD Check Pion 150 35 Sensor scan 4x4x20 Tungsten Pion 150 12 Muon 150 42 Electron 150,100, 80,50, 30 ,20 ,10 399/37~89 4x8x10 Tungsten Pion 150 3 Muon 150 18 Electron 150, 100, 50, 20 162/36~48

Channel Scan for MIP calibration Channel summary noisy(~10%) ADC unstable(~5%) deal channels (~5%) One panel of sensor shown as an example

Gain Calibration of Individual Channels Pedestal : Gaussian Fit Mean : 5206.9 Sigma : 7.2 150 GeV Muon Beam Scan over All 640 Channels Size of signal from the pedestal level of a channel is used to calibrate the channel S/N (signal to noise rate) = 5.2 (5243 -5207)/7.2 Signal : Landau Fit Peak : 5243 ADC Counts

Detector Response to Different Particles First look of data Just sum of all channels Including noisy, bad and dead channels Not optimized detector No calibration No beam position information considered 50 GeV Electron 50 GeV pion 150 GeV Muon Total ADC of an event / 640

Detector Response to Electron Beam(sum of all channel) First look of data 150 GeV Electron 100 GeV Electron 80 GeV Electron 50 GeV Electron 30 GeV Electron 20 GeV Electron 10 GeV Electron Total ADC of an event / 640

Calorimeter Calibration : ADC vs. Beam Energy First look of data Very preliminary Total ADC above pedestal / 640 Fit to Straight Line -> Slope 4.2 (ADC/GeV) Electron Energy in GeV

Energy Resolution vs Energy First look of data Very preliminary dE / E (%) Electron Energy in GeV

Summary 1. Beam test of Silicon-Tungsten during Aug. 30 to Sep. 7 at CERN 2. ~50GB data collected using electron, muon and pion beam 3. Analysis is under way : noisy, unstable, dead channel. leakage due to large effective RM (52mm) not optimized electronics and detector for LC calorimeter 4. Require detailed MC study for the accurate geometry 5. Si/W Detector is working . The result will be presented in next LCWS. 6. In Korea, R&D for LC calorimeter is going on. This beam test experience will give positive idea for R&D activity.