Quick Report on Silicon G-APDs (a.k.a. Si-PM) studies XIV SuperB General Meeting LNF - Frascati Report of the work done in Padova Dal Corso F., E.F., Simi G., Stroili R. University & INFN Padova
Outline Studies on-going on different Silicon G-APDs FBK (Irst), Hamamatsu, 1 mm2 to 9 mm2 Measuring the gain Radiation Tests @ LNL (INFN Legnaro National Labs) Different energy, fluence and G-APDs Preliminary Comparison Low Cost Power supply Stability 2
Measuring the gain Hamamatsu 9mm2 50μm FBK 1mm2 40μm Measuring the distance between two photoelectrons peaks, but... 3
Fitting the spectrum FBK 1mm2 40μm 0 1 2 3 Poisson Gauss CrossTalk: Binomial Probability 4
Fit Results FBK 1mm2 40μm Hamamatsu 1mm2 50μm Hamamatsu 3x3mm2 50μm 5
Fit Results: No AfterPulsing Hamamatsu 1mm2 50μm FBK 1mm2 40μm Hamamatsu 3x3mm2 50μm 6
Neutrons irradiation tests @ LNL Device irradiated during tests in June and July: 2 G-APD (1 mm2-50 μm pixel size from Hamamatsu) 1 G-APD (1 mm2-40 μm pixel size from FBK) 1 G-APD (2x2 mm2-50 μm pixel size from FBK). Deuteron beam over beryllium thick-target: 9Be(d,n)10 B Ed: 4 MeV Beam current: ~ 40 na Temperature 20ºC 2 different sets of measurements 28,29-June and 8,9 July 1 Hamamatsu & 1 FBK both 1 mm2 23 and 26 July 1 Hamamatsu 1mm2 & 1 FBK 4mm2 7
Neutron Fluence First set Dark counts rate [Hz] 6.00E+06 9-July 8-July 29-June 7.00E+06 28-June Reached Fluence of N1MeV eq ~ 2x10 10 : 5.00E+06 4.00E+06 3.00E+06 2.00E+06 1.00E+06 0.00E+00 0.00E+00 5.00E+09 1.00E+10 1.50E+10 2.00E+10 2.50E+10 FluenceNeq/cm2 8
6.00E+06 9-July 7.00E+06 8-July 28-June 8.00E+06 29-June First sets: Dark Counts Rate vs Time Dark Counts [Hz] 5.00E+06 4.00E+06 3.00E+06 2.00E+06 1.00E+06 0.00E+00 0 100000 200000 300000 400000 500000 600000 Time[sec] 9
First Set Comparison: Before/After Gain, Hamamatsu Before and After the Irradiation for different temp. 35 C 10 C 7.5 6 6.5 5 5.5 mv 4 A fte r B e fo r e mv 7 4.5 3 3.5 2 2.5 1 6 8.2 6 8.7 6 9.2 6 9.7 7 0.2 7 0.7 1.5 69.5 7 1.2 A fter B e fo r e 70 7 0.5 71 71.5 72 V V 20 C 40 C 8 6.8 7 5.8 6 4.8 Afte r Be fo r e 4 A fter B efo r e mv mv 5 3.8 3 2.8 2 1 6 8.5 69.9 1.8 69 6 9.5 70 V 7 0.5 71 71.5 7 0.4 7 0.9 7 1.4 V 71.9 10
Neutron Fluence Second set neutron 1 MeV eq. /cm2 9.0E+09 8.0E+09 7.0E+09 6.0E+09 Flunce 5.0E+09 4.0E+09 3.0E+09 2.0E+09 1.0E+09 0.0E+00 0 3600 7200 10800 14400 18000 21600 25200 28800 32400 36000 39600 43200 Time [sec] 11
Hamamatsu 26-July 23-July 24/25-July Dark counts rate FBK 12
Comparison Before/After Second set Hamamatsu 40 C 20 C 6.8 0 5.5 5 5.8 0 4.5 4.8 0 mv 3.5 Before After 3 B e fo r e Ir r a d ia tio n A fte r Ir r a d ia tio n mv 4 3.8 0 2.5 2.8 0 2 1.5 1 69.5 1.8 0 71 70 70.5 71 71.5 72 72.5 73 73.5 7 1.5 72 7 2.5 73 7 3.5 74 V 74 V 2.4 71 f(x) = 0.06x + 68.18 2.2 70.5 2 69.5 1.8 slope V0(V) f(x) = 0.06x + 68.18 70 69 f(x) = 0.01x + 1.54 f(x) = 0x + 1.93 1.6 1.4 68.5 1.2 68 1 67.5 10 15 20 25 T(C) 30 35 40 10 15 20 25 T[C] 30 35 1340
Healing These two devices have been monitored for more than a month 14
Extreme Low Costing G-APD Power Supply (35$ w/ PCB) Evaluated the Maxim MAX15031: consists of a constant-frequency (400kHz) pulse-width modulating (PWM) step-up DC-DC converter with an internal switch and a high-side current monitor with high-speed adjustable current limiting. can generate output voltages up to 76V provides current monitoring up to 4mA (up to 300mW) operates from 2.7V to 11V operates over the -40 C to +125 C temperature range Very small dimension (Chip SMD) ~4mm2 15
Maxim Stability Variation of the Maxim APD Voltage as a function of the LV setting Variation of the Maxim APD Voltage as a function of the Temperature for different LV setting 71.02 70.99 70.98 LV = 5.0 V 71 APD Voltage [V] APD Voltage [V] 70.97 70.96 70.95 70.94 70.93 70.92 70.91 70.9 70.89 70.98 70.96 70.94 LV = 3.3 V 70.92 70.9 70.88 3 3.5 4 4.5 5 5.5 LV [V] 6 70.86 0 10 20 30 40 50 60 T[ C] 70 16
Switching Frequency 17
Summary/to-do Finish the comparison before/after irradiation for FBK G-APDs Compare the noise too Setup a faster way to measure the gain (maybe with threshold scan?) Perform further irradiation test with neutron at LNL with different Si G-APDs Study the power supply noise induced by switching frequency 18
Backup Backup slides 19
NIEL-scaling theory Any particle fluence can be reduced to an equivalent 1 MeV neutron fluence producing the same bulk damage. The scaling is based on the hypothesis that generation of bulk damage is due to non-ionising energy transfer to the lattice. Φ eq = k Φ abs Φ abs Y ( E ) sr µc = S cm 2 k=k(ed) : hardness parameter D ( E ) σ ( E ) de k= σ ( E ) de n La Biodola, 31 May 2010 20
Temperature Stability during August Si-PM monitoring Temperature Sensor on the inner box layer Temperature Sensor near the Si-PM 21
Maxim Description The MAX15031 consists of a constant-frequency pulse-width modulating (PWM) step-up DC-DC converter with an internal switch and a high-side current monitor with high-speed adjustable current limiting. This device can generate output voltages up to 76V and provides current monitoring up to 4mA (up to 300mW). The MAX15031 can be used for a wide variety of applications such as avalanche photodiode biasing, PIN biasing, or varactor biasing, and LCD displays. The MAX15031 operates from 2.7V to 11V. The constant-frequency (400kHz), current-mode PWM architecture provides low-noise output voltage that is easy to filter. A high-voltage, internal power switch allows this device to boost output voltages up to 76V. Internal soft-start circuitry limits the input current when the boost converter starts. The MAX15031 features a shutdown mode to save power. The MAX15031 includes a current monitor with more than three decades of dynamic range and monitors current ranging from 500nA to 4mA with high accuracy. Resistor-adjustable current limiting protects the APD from optical power transients. A clamp diode protects the monitor's output from overvoltage conditions. Other protection features include cycle-by-cycle current limiting of the boost converter switch, undervoltage lockout, and thermal shutdown if the die temperature reaches +160 C. The MAX15031 is available in a thermally enhanced 4mm x 4mm, 16-pin TQFN package and operates over the -40 C to +125 C automotive temperature range. 22