CIEMAT Spanish WA105 meeting 12 - 09 - 2016 PMTs tests status CIEMAT Spanish WA105 meeting 12 - 09 - 2016

Setup for linearity measurements Monitor 2 R5912-02 @ Room temp Diffuser Fiber splitter Filters box Fiber splitter Laser(405 nm) Optical fiber Fixed Filter LED & Laser controller Black box QDC LabView Diffuser Signal from PMTs PMT under test R5912-02 Monitor 1 R6041-506 @ room temp Details: - A diffuser at the end of each fiber provide an homogeneous illumination of the photo-cathode. - The function of the PMT monitor #1 is to keep track of possible variations in the lighting system. The light input is reduced by a filter to keep the PMT on its linear response region Dewar for LN2

Light setup for light noise background tests Fiber splitter Filters set #1 Fiber splitter Laser(405 nm) Filters set #2 Optical fibers Laser(405 nm) LED & Laser controller QDC LabView Diffuser Signal from PMTs Monitor PMT R6041-506 @ room temp PMT under test R5912-02 Details: - Two independent light sources to pulse signal and noise simultaneously Dewar for LN2

Problems found in the setup Non linearity of the QDC (solved by characterization) Laser in-stability with time. Improved after reparation.

Tests performed Room temperature Gain vs HV Dark current rate Linearity vs light intensity Linearity vs light pulses frequency (TBA) Response with a light noise background (TBA) LN2 temperature Gain vs HV (TBA) Dark current rate (TBU) Linearity vs light intensity (TBA)

Linearity vs light @ room T Gain: 1000V ≈ 10^6 1180V ≈ 10^7 1450V ≈ 10^8

Linearity vs light @ room T (zoom: 0- 100 PE) Gain: 1000V ≈ 10^6 1180V ≈ 10^7 1450V ≈ 10^8

Dark current rate vs HV Room T According to literature the dark rate at LN2 temperature should not depend on the voltage LN2 T

Dark current rate vs time (evolution for a single voltage)

Caracteristicas de la luz esperada en el detector 6x6x6. Resumen 1GeV v -> 10000 PE -> 300 Pes/ PMT/ GeV v Señal max 10GeV -> 3000 Pes/PMT Muon max 6GeV -> 1800 Pes/PMT Rate señal: 100Hz Rate muones: de 7KHz (1 / 143us) a 14KHz (1/71.4us) ->100 muones cada 8ms Duración de la señal (S1): 5us (5x100 = 500us cada 8ms o 1/16 del intervalo Duración de la señal (S2): 30us (6/16 del intervalo) Drift time (6m): 4ms (distancia S1-S2) En una ventana de 25ns: Contribución de S1: 0 a 8000 pe (mayor densidad entre 1 y 500pe) Contribución de S2: 1 a 200 pe (centrado en 50 pe)

Light-noise background tests En el detector tendremos un fondo de ruido producido por los cósmicos con un rate de 14KHz (1/71.4us) ->100 muones cada 8ms (0.001 cada 200ns). Cada cósmico produce una señal S1 con entre 40 y 4000 pe (solo la componente rápida: 20-30ns) y un S2 con entre 0,5 PE y 600 PE (en 400ns). Al ser la duración de S2 mucho mayor que la componente rápida de S1 voy a considerar solo S2 como background de ruido. - Senal de interes (S1 sincrona con el haz) @ 100Hz: de 40 a 4000pe (en 400ns) Tests: Señal de interés: S1 = 10 PE, 40 PE, 200 PE, 400 PE (ventana de 200ns) con una frecuencia de 100Hz Para cada una de las medidas anteriores superponer un ruido de entre 1 y 40 PE distribuido como SPEs en 200ns

light-noise background tests (signal ≈10 spe)

Gain vs Voltage @ room T

Linearity vs light (PMT 8 in) @ room T

Linearity vs light (PMT 8 in) @ room T