Callibration of SVD2 RadFET chips ================================= We have two boxes containing 4 mounted RadFET chips each. All chips are from the new batch obtained from A.H. Siedele via IJS in Ljubljana in May 2002, same as will be used in SVD2. Except for capton #3, captons with bonded chips with only one working k range FET were used. r range fets were not bonded at all. Photos of the captons and this text can be found at http://beauty.bk.tsukuba.ac.jp/~stanic/belle/rad/ 0. RadFET and Aminogray responses before irradiation ==================================================== Green sample --------------------- sensor# k1 k2 0 9.91 short 1 9.77 short 2 short 9.53 3 10.85 9.43 --------------------- Average (1k1+2k2)/2 9.65 Average (0k1+1k1+2k2+3k2)/4 9.66 Blue box sample --------------------- sensor# k1 k2 14 -13.6 9.5 20 -1.3 9.5 21 9.5 12.7 22 -13.6 -13.6 Aminograys before irradiation (Terazaki, U.Tsukuba) --------------------------------------------------- Following are the Aminogray results from 2002/7/5. Total dose in the following table is obtained from the amount of free radicals, which is proportional to total dose, but the free radicals of Aminogray dosimeter reduce as long time goes by. The difference of the total dose between before and after the radiation experiment is the amount of the radiation obtained in the experiment. Sample power (mW) Range Pen (mm) Total dose (kRad) ---------------------------------------------------------------- 239 4 2 176 214 240 4 1.25 194 378 245 4 1 223 543 245 1 1 115 548 246 4 1 185 451 246 1 1.25 155 450 247 4 5 157 76 247 1 5 105 76 248 4 5 192 94 248 1 6.3 158 91 010311-31 4 100 13 0.32 ---------------------------------------------------------------- 1. Calibration at high dose rate (80kRad/h) (blue sample) ========================================================= In order to confirm the validity of the calibration curves obtained at TIT with the RadFET chips from SVD1 batch, we repeated the irradiation with the SVD2 RadFET chips as well (to as high a dose as can be obtained in 1-2 days of irradiation) on 2002/8/29-30. Data was continously logged by our standard system (Woolongong RadFET reader and UT data logger). Irradiation on 2002/08/29-30 (with online readout, blue box) ------------------------------------------------------------ #33 2083 #34 2152 --------------- average aminorgray 2117kRad in 25h38m = 82.59 kRad/h from source acitivity at 10cm distance 75.5 kRad/h (by TIT) -------- average = 79 kRad/h (with 10% error) Distance of the samples from 60Co source 10cm, estimated dose rate from source activity 75.5kRad/h. Irradiation time: from 8/29 10:37 to 8/30 12:15. During irradiation all 3 working RadFETs died, 2 of them gradually (#14 k2 and #21 k1) after about 1 hour (80kRad). The third one (#20 k2) died abruptly after 13.3 hours (1000Mrad). Data from this RadFET agrees with previous data from 500kRad irradiation. 2. Calibration at low dose rate (1.6kRad/h) with no readout (green) =================================================================== The sample will be irradiated in the TIT 60Co irradiation facility at a distance of 70cm (50x lower dose rate than previous irradiation experiments) until the total accumulated dose according to the estimate from the source activity and distance reaches 100kRad. After irradiation, dose estimate will be checked by Aminogray readings. As we intend to use 60Co source as a (together with whatever other irradiation will be in progress) we expect the irradiation to take about 1 month. After that, the sample will be rought back to KEK and the RAdFETs and Aminograys re-measured. With this experiment, we intend to find out possible dose rate dependence of the RadFET sensors. Captons are equipped with connectors, and gate and drain of the RadFETs are shortened for the irradiation by inserting an Al bridge in the connector. a. RadFET responses ################### 2002/7/22 (after irrad. to 100kRad, green box sample) ----------------------------------------------------- RadFET 2002/7/11 2002/7/22 2002/8/6 ----------------------------------------------------- sensor# k1 k2 k1 k2 k1 k2 0 9.91 sh 9.57 sh 9.57 sh 1 9.77 sh 9.39 sh 9.35 sh 2 sh 9.53 sh 8.11 sh 8.24 3 10.85 9.43 7.68 7.88 7.80 7.98 ----------------------------------------------------- Avg 1+2 8.79 (0.86) Avg 1+2+3+4 8.78 (0.87) After irrad. to total 500kRad ----------------------------------------------------- RadFET 2002/9/9 2002/9/11 2002/9/17 ----------------------------------------------------- sensor# k1 k2 k1 k2 k1 k2 0 9.34 +12.8 9.36 12.8 9.35 13.0 1 4.07 -13.5 4.17 -13.5 4.19 -13.5 2 +13 4.57 12.8 4.63 13.0 4.66 3 9.57 -13.5 9.45 -11.7 -13.5 -12.47 ----------------------------------------------------- Avg 4.42 (5.23) After irrad. to total 700kRad (no additional sensors died) ----------------------------- RadFET 2002/10/24 ----------------------------- sensor# k1 k2 0 9.12 +12.8 1 3.17 -13.5 2 +12.8 3.65 3 9.65 -13.5 ----------------------------- Avg 3.41 (6.24) After irrad. to total 900kRad ------------------------------------ RadFET 2002/11/21 2002/12/03 ------------------------------------ sensor# k1 k2 k1 k2 0 9.24 +12.8 / / 1 2.32 -13.5 2.53 / 2 +12.8 2.91 / 3.09 3 9.54 -13.5 / / ------------------------------------ Avg 2.62 (7.04) 2.81 (6.84) After irrad. to total 1100kRad ------------------------------ RadFET 2003/01/09 sensor# k1 k2 0 9.3 / 1 1.89 / 2 / 2.49 3 / / ------------------------------ Avg 2.19 (7.46) After irrad. to total 1300kRad ------------------------------------ RadFET 2003/03/17 2003/03/27 sensor# k1 k2 k1 k2 0 8.99 13.03 9.1 / 1 1.54 -13.4 1.68 / 2 12.75 2.32 / 2.47 3 9.30 -13.5 / / ------------------------------------ Avg 1.93 (7.72) 2.08 (7.57) After irrad. to total 1500kRad -------------------------------------------------- RadFET 2003/04/17 2003/03/21 2003/05/01 sensor# k1 k2 k1 k2 k1 k2 0 8.69 12.86 / / / / 1 1.1 -13.6 1.2 / 1.33 / 2 12.7 1.8 / 1.91 / 2.01 3 9.09 -13.56 / / 9.00 / -------------------------------------------------- Avg 1.45 (8.2) 1.55 (8.1) 1.67 (7.98) (in average only 2_k1 and 3_k1 are counted as they are the only two sensors with voltages close to the average of this RadFET batch) Measurement is repeated after a few weeks when the annealing is more or less over. b. Dosimetry ############ To the green sample 4 Aminogray dosimeters were attached: Aminogray 2002/07/11 (before irradiation) Aminogray Meas. dose before irrad. sensor# 2002/7/11 (kRad) --------------------------------- 9602241-247 76 9602241-248 92.5 010311-31 0.32 (new) 010311-32 0. (new) --------------------------------- Aminogray 2002/07/22 (after irrad. to total 100kRad, gren box sample) --------------------------------------------- Aminogray meas.1 meas.2 meas.3 (krad) --------------------------------------------- #247 96.7 97.1 104.0 #248 93.2 101.8 #0103-11-31 99.5 99.5 93.7 #0103-11-32 99.5 99.6 94.4 --------------------------------------------- average 98.1 kRad total average 98.1 kRad Aminogray 2002/8/30 (after irrad. to total 500kRad) --------------------------- sample dose (kRad) #247 454 #248 449 #31 455 #32 455 --------------------------- average 453.25 kRad total average 551.35 kRad Aminogray 2002/10/24 (after irrad. to total 700kRad) ------------------------------------------------------------ Number Total dose (kRad) Irrad.dose this time (kRad) 247 865 248 248 905 291 32 783 247 ------------------------------------------------------------ average 262 kRad total average 813 kRad Aminogray 2002/11/26 (after irrad. to total 900kRad) --( TIT )----------------------------------------------------------- Number Total dose (kRad) Irradiated dose this time(kRad) 247 1093 228 248 1144 229 32 1058 275 -------------------------------------------------------------------- average 244 kRad total average 1057 kRad --( SVD 1.2 )------------------------------------------------------- Number Total dose (kRad) 233 38.2 234 22.4 --( SVD 1.4 )------------------------------------------------------- Number Total dose (kRad) 202 59.0 203 51.2 Aminogray 2003/01/09 (after irrad. to total 1100kRad) -------------------------------------------------------------------- Number Total dose (kRad) Irrad. dose this time (kRad) 247 1345 252 248 1324 179 32 1302 243 -------------------------------------------------------------------- Average 1324 225 Aminogray 2003/03/19 (after irrad. to total 1300kRad) -------------------------------------------------------- Aminogray# Total dose (kRad) This time (kRad) 247 1335 32 248 1410 65 32 1391 68 -------------------------------------------------------- Average 1379 55 Aminogray 2003/04/21 (after irrad. to total 1500kRad) ==( TIT )========================================================== Number Total dose (kRad) Irradiated dose on this time(kRad) 247 1487 77 248 1476 83 32 1434 99 ---- Average 1466 86 Aminogray 2003/06/30 ==( TIT )========================================================== Number Total dose (kRad) Irradiated dose on this time(kRad) 247 1546 59 248 1530 74 32 1512 78 39 171 171 ---- Average 1530 96 Aminogray 2003/12/01 ==( TIT )========================================================== Number Total dose (kRad) 247 2246 248 2295 39 181 == new Aminogray ==================================================== Number Total dose(kRad) 243 0 244 0 Dear monitoring people, Tsuboyama san, Nakano san, and I measured Aminogray. The Total dose of numbers 247 and 248 increased for about 10% with regard to the measurement on 2003/06/30. Best regards, Iwaida Table: ====== Dose [kRad] Avg. (1K1+2K2) Calc. Meas. volt. /2 1K1 2K2 [V] Date ---------------------------------------------------------- 0 0 0 9.65 9.77 9.53 2002/07/11 100 98 0.86 8.79 9.35 8.24 2002/07/22 500 551 5.23 4.42 4.19 4.66 2002/08/30 700 813 6.24 3.41 3.17 3.65 2002/10/24 900 1057 6.84 2.81 2.53 3.09 2002/11/26 1100 1324 7.46 2.19 1.89 2.49 2003/01/09 1300 1379 7.72 2.08 1.68 2.47 2003/03/19 1500 1466 7.98 1.67 1.33 2.01 2003/04/21