SDD status at KEK 30 July 2009 Current

SDD status at KEK 30 July 2009

Current situation Summary of previous meeting report; 1. Installation preamp inside the vacuum chamber works well (resolution: ~150 e. V in FWHM) 2. Checked preamp temperature dependence ~ resolution constant 150 e. V around Chip temperature 255~275 K 3. stability against day-long measurement ~resolution and chip , finger temperature are stable. Contents of Today’s report: 1. Study of the Signal fall down time 2. Checked substrate voltage dependence 3. Test the new SDD rod for the E 17 cryostat

Signal fall down time 1: Trigger rate in ramp up time ~40 Hz is not change through measureme nt. 2: The finger temperature is stable. =>SDD temperature is stable. 270 K (100 us) Tchip[K] Tdrop[us] 270 ~300 260 ~800 A Signal fall down time depends on the chip temperature sencitively. The substrate volatage also affect this time length. 260 K (200 us) Fall down time ( Vsub , Tchip ) should be reduced -> With the information of Resolution (Vsub, Tchip), we decide Vsub voltage and Tchip optimized value.

Result Vsub [V] Tchip [K] Tdrop [μs] Resolution [e. V](Mn. Ka) -6. 0 277. 523 346 145. 35 -6. 0 267. 0059 744 148. 18 -6. 0 255. 379 4700 154. 56 -5. 0 251. 9194 11000 150. 237 -5. 0 262. 6887 1910 150. 863 -5. 0 277. 2408 300 151. 116 -4. 0 250. 2457 6480 154. 454 -4. 0 261. 9153 520 152. 826 -4. 0 273. 9788 248 158. 441 • Preamp “sub” supply was used to as SDD bulk voltage supply. If we use external power supply to apply bulk voltage, unavoidable oscillation caused on preamp out. • ** Tchip means temperature of the preamp chip. Shown values are avaraged value of during time of measurement. • ***Tdrop measured with oscilloscope. • Resolution is FWHM of Mn. Ka spectrum

Fall down time v. s. Temperature Fall down time[μs] The chip temperature should be kept around 270~280 K. Temperature[K]

280 Temperature [K] 260 Minimize fall down time <1 ms Preamp chip 240 220 200 180 Preamp housing Heater temperature 160 Finger temperature 140 120 Time [min] 200 250 300 When the temperature of Preamp housing is around 190 K, we can keep the chip temperature at 270 K. And E 17 cryostat with sato box, we will be able to controll the temperature of preamp housing from 80 K to 230 K.

Resolution v. s. Temperature/ substrate 200 190 180 Mn. Kα resolution [e. V] 170 160 150 140 130 There is no change in an optimized range of substrate voltage(-4. 5 V ~ -6. 5 V) Preamp chip temperature is not affect to resolution. 120 110 100 245 250 255 260 265 270 Temperature[K] 275 280

Substrate voltage monitor Preamp SDD GND SUB V Substrate voltage stability check Time [min] 0 60 150 210 300 Vsub [V] -6. 5 -6. 488 -6. 497 -6. 475 -6. 472

Fall down time v. s. Temperature 100000, 00 Fall down time[μs] ●Vsub=-6. 5 V ●Vsub=-5. 5 V ●Vsub=-6. 0 V ●Vsub=-5. 0 V ●Vsub=-4. 0 V 10000, 00 100, 00 245, 00 250, 00 255, 00 260, 00 265, 00 Temperature[K] 270, 00 275, 00 280, 00

Resolution v. s. Temperature/ substrate 200 190 180 170 Mn. Kα resolution [e. V] 160 150 140 Result of Vsub of -5. 5 V is ~150 e. V. It is consistent to long term measurement. 130 ●Vsub=-6. 5 V ●Vsub=-5. 5 V ●Vsub=-6. 0 V ●Vsub=-5. 0 V ●Vsub=-4. 0 V 120 110 100 245 250 255 260 265 Temperature[K] Vsub = -6. 5 V , Tchip = 275 K (Preamp housing temperature ~ 190 K) 270 275 280

Instllation of the SDD system in the E 17 cryostat 80 K ☑check sdd temperature dependence ~ optimim is around 130 K □Finding setup to keep sdd temperature at around 130 K ☑ New sdd arm ☑ New sdd rod and housing ☑thermal condition of the preamp box~ 80 to 230 K variable, very small effect on 1 K part and sdd support ☑check chip temperature dependence~ constant and stable ☑ check substrate dependence ☑ temperature and sub dependence of signal fall down time

New sdd rod setup 80 K 130 K 1 Plastic sheet was removed 80 K 2 Tefron washer was inserted between (Al)basis and rod. (->130 K) Only by using new sdd rod and some insulator such like teflon washer, We must keep SDD temperature at around 130 K. 3 New sdd rod. It was fixed by SUS/Brass screw.

New sdd rod Teflon washer SDD rod for E 17 cryostat Brass / SUS screw

New sdd rod Alminized mylar (Attach to Finger ) Pt 100

A new sdd housing Cooling(Brass screw) Temperature [K] 300 280 260 240 220 200 180 160 140 120 100 Preamp SDD rod Min. 163. 8 K 0 100 200 300 Time[min] 400 Finger temperature~ 80 K. A minimum value of sdd housing(rod)temperature is 163 K. (w/ tefron washer) Mylar window ~130 K. 500

Result 165 162 2068, 0 160 158 155 Resolution [e. V] Center position[ch] 2069, 0 2067, 0 2066, 0 2065, 0 120 220 320 Time [min] A SDD temperature did not decrease less than 160 K. However, resolution still was kept around 150 e. V. (In the left figure, resolution is around 155 e. V and it is not so good, it was caused noise from thermometer line. We detach these lines, resolution back to 150 e. V(147 e. V)) 156 150 154 145 152 140 150 120 220 320 Time [min] SDD temperature 80[K] 130[K] 180[K]

Summary • Fall down time increase exponentially with decreaseing preamp chip temperature. It is minimized (~<1000 μs)at the chip temperature of 270 K with temperature of preamp housing of 190 K. The temperature of the preamp support in the E 17 cryostat can be controlled from 80 K to 230 K. So we can now install preamp in E 17 cryostat • The optimized range of the substrate voltage is not changed by a preamp position. (set inside of the cryostat or outside. ) • The new SDD rod and other appratus have good thermal insulativity. The rod temperature cannot be cool down less than 160 K, but a SDD resolution is still good ~150 e. V. A sdd operational temperature range is now sured that 130~170 K.

Schedule • Test with E 17 cryostat Substrate -6. 5 V, R 1=-20 V RX=-130 V Back=-60 V Preamp: +-24 V type • Check new sdds from vienna (4)

Fall down time[μs] 14000 12000 10000 8000 6000 4000 2000 0 (7, 00) (6, 00) Substrate voltage [-V] (5, 00) (4, 00)

2000 1800 1600 1400 1200 1000 800 600 400 200 0 (7, 00) (6, 50) (6, 00) (5, 50) (5, 00) (4, 50) (4, 00)

162 160 158 156 154 152 150 158, 8 163, 8 168, 8 173, 8 178, 8 183, 8

Result 165 300 Center position[ch] 2069, 00 Resolution [e. V] 2068, 50 2068, 00 2067, 50 2067, 00 2066, 50 2066, 00 2065, 50 2065, 00 0 0 100 200 Time [min] 300 162 160 250 155 160 200 156 158 154 145 150 152 140 100 150 0 A SDD temperature did not decrease less than 160 K. However, resolution still was kept around 150 e. V. (In the left figure, resolution is around 155 e. V and it is not so good, it was caused noise from thermometer line. We detach these lines, resolution back to 150 e. V(147 e. V)) Next : Mylar wind 0 50 100 150 200 250 Time [min] SDD temperature 80[K] 130[K] 300 180[K] 350

Vsub [V] Tchip [K] Tdrop [μs] Resolution [e. V] -5. 5 250. 25 pm 0. 1 84. 4 148 -5. 5 260. 9 pm 0. 1 12. 7 150 -5. 5 268. 8 1. 76 149. 84 -6. 5 249. 95 30. 2 147. 021 -6. 5 261 4. 92 147 -6. 5 269. 4 1. 27 150