production pmt testing and work on site with prototype tank university of california, los angles...
DESCRIPTION
Production PMT test system in push-button operation Detailed understanding of energy calibration of individual tanks in engineering array Using this to understand energy cal of showers Regular contributions to site In One Year…TRANSCRIPT
Production PMT Testing and Work
on Site with Prototype Tank
University of California, Los AnglesDepartment of Physics and
Chris JillingsChris Jillings
November, 2000
Production PMT testing1. Requirements2. Light source3. Electronics and DAQ
Prototype tank (Sept 2000) Low gain or high gain
Talk Outline
Production PMT test system in push-button operation
Detailed understanding of energy calibration of individual tanks in engineering array
Using this to understand energy cal of showers
Regular contributions to site
In One Year…
48 PMTs in one day Measure
1. Linearity2. Gain / Dark rate vs voltage3. Pulse shape4. Afterpulsing
Production PMT Testing
The Lab in the STRB
Schematic
Overview
Need 1% stability for linearity
Timing on 25 ns scale Wide range of brightness
Light Source
Blue LEDBlue LED
TTL logic to control two LEDs in each source
Analog line to control brightness
Counter/timer to trigger source PCI 6025E from Nat. Inst. Small amount of custom TTL
circuitry
Light Source
Our current triggering circuit will work
High Voltage Standard system (CAEN SY403) HV supply on the base
Needs 5V for powerAnalog level to control HV
Disc. for noise rate Two ADC’s per PMT
1. Auger has 15 bits dynamic range
2. Commercial ADC has 10 to 12
Multiplexing for PMT signal digitization
CAMAC/NIM System
Either1. Digital scope with GPIB2. PCI card with 100 MHz
digitizer Both require multiplexing
Pulse Shape
Automated analysis1. Yes/no/maybe?2. Linearity curve3. Gain/Dark Rate vs HV4. Pulse shapes
Archive plots and complete data tables using HTML interface
Root macros to read data
Analysis and Archiving
On-Site Work
Clear sky
High elevation
Plateau
Fluorescence detector
September 2000
On-Site Progress
On-Site Progress
On-Site Goals
Test over-wintered tank Number of pe per muon
Learn electronics/DAQ Requirements for PMT
tests Contribute to site
Prototype Tank
Muons in Tank
PMT 1 PMT 2
PMT 3
10 mV per division
100 ns per division
Muons in Tank
Gain = 106
Average Muon Pulse
12 m atten length
Low Gain (105)1. Amplify last dynode for
small signals2. Use anode for large
signals High Gain (106)
1. Anode for small signals2. Deep dynode for large
signals
Gain???
Back at UCLA… Tap dynode 8 of 12 of ETL
PMT The signals look beautiful
Deep Dynode Tap
Deep Dynode Tap
Linearity Still Not There
Run at about 2105 gain PMT test stand designed
PMT test stand to be built Contribution to site Energy calibration
Conclusions