some photos in high resolution of the test setup 5-10 October 2015

Observe c. 2mV p to p noise with DSO ( Z_in = 50 Ohm ) c. 60us period with HF structure. DSO connected to junction box via 34-way IDC - 16x Lemo-00 adaptor.

Origin of noise upstream of 4x34-way to 8x16-way Junction Box. Not microphonics from Edwards RV5 Rotary Pump.
No change observed with simple ground connections between NIM bin/+/-15V PSU/Junction Box and MSL type W1 preamplifier units/vacuum chamber/support assembly.


Estimate of electronic noise

Pulser BNC PB-5

Amplitude 0.5V
Attenuation x1
Decay time 1ms
Frequency 50Hz

Preamplifier RAL108
Output impedance 100 Ohm
Sensitivity 20mV/MeV ( into high Z load ), 6.7mV/MeV ( into 50 Ohm load ) 

Amplifier EG&G Ortec 571
Input terminated by 50 Ohm
Gain x1 (internal) x 1.0 (fine gain) x 50 (coarse gain ) = 50
Shaping time 0.5us

MCA Amptek 8000D
Input FSR 10V
12 bit ADC


Nominal gain = 6.7mV/MeV x 50 = 335mV/MeV

12 bit ADC input FSR = 10V / 0.335V/MeV = 29.85MeV FSR or 7.3keV/channel


dE p+n junction strip # 4 ( of 0-15 )

pulser peak centroid = 799.8 ch
pulser peak width = 7.8 ch FWHM = 57 keV FWHM


E p+n junction strip # 4 ( of 0-15 )

pulser peak centroid = 864.8ch
pulser peak width = 3.5 ch FWHM = 26 keV FWHM


E n+n Ohmic strip # 4 ( of 0-15 )

pulser peak centroid = 913.0 ch
pulser peak width = 5.3 ch FWHM = 39 keV FWHM


Noise estimates are probably accurate to c. 10% level.

Check RAL108 +/-15V PSU

Measured output voltages +15.21V -15.18V - OK

Observe output voltages with DSO ( ch #1 AC/1M +15V, ch #2 AC/1M -15V ) - see attachments 1 & 2

What we should observe is c. 1mV rms ( white ) noise but we clearly observe similar noise transients ( c. 60us period with HF structure ) to those observed at RAL108 
outputs. The RAL108 preamplifier units do have RC filters on the +/-15V - typically c. 100 Ohm and 4.7uF. Some additional, inline filtering with a lower rolloff 
frequency may be required.

> 
> Observe c. 2mV p to p noise with DSO ( Z_in = 50 Ohm ) c. 60us period with HF structure. DSO connected to junction box via 34-way IDC - 16x Lemo-00 adaptor.
> 
> Origin of noise upstream of 4x34-way to 8x16-way Junction Box. Not microphonics from Edwards RV5 Rotary Pump.
> No change observed with simple ground connections between NIM bin/+/-15V PSU/Junction Box and MSL type W1 preamplifier units/vacuum chamber/support assembly.
> 
> 
> Estimate of electronic noise
> 
> Pulser BNC PB-5
> 
> Amplitude 0.5V
> Attenuation x1
> Decay time 1ms
> Frequency 50Hz
> 
> Preamplifier RAL108
> Output impedance 100 Ohm
> Sensitivity 20mV/MeV ( into high Z load ), 6.7mV/MeV ( into 50 Ohm load ) 
> 
> Amplifier EG&G Ortec 571
> Input terminated by 50 Ohm
> Gain x1 (internal) x 1.0 (fine gain) x 50 (coarse gain ) = 50
> Shaping time 0.5us
> 
> MCA Amptek 8000D
> Input FSR 10V
> 12 bit ADC
> 
> 
> Nominal gain = 6.7mV/MeV x 50 = 335mV/MeV
> 
> 12 bit ADC input FSR = 10V / 0.335V/MeV = 29.85MeV FSR or 7.3keV/channel
> 
> 
> dE p+n junction strip # 4 ( of 0-15 )
> 
> pulser peak centroid = 799.8 ch
> pulser peak width = 7.8 ch FWHM = 57 keV FWHM
> 
> 
> E p+n junction strip # 4 ( of 0-15 )
> 
> pulser peak centroid = 864.8ch
> pulser peak width = 3.5 ch FWHM = 26 keV FWHM
> 
> 
> E n+n Ohmic strip # 4 ( of 0-15 )
> 
> pulser peak centroid = 913.0 ch
> pulser peak width = 5.3 ch FWHM = 39 keV FWHM
> 
> 
> Noise estimates are probably accurate to c. 10% level.

Neutron beam profile - film exposure overnight 12/13.9.24

08.35 Vacuum chamber pressure OK - see attachment 1

MWDdetector and UserInput

MSL type W1(SS)-20

3186-9  20um Depletion voltage 3V Operating voltage 6V
3585-12 20um Depletion voltage 2V Operating voltage 4V

MSL type W1(DS)-150

3458-1 157um Depletion voltage 22V Operating voltage 52V
3458-4 144um Depletion voltage 18V Operating voltage 48V

Process alpha data
- Compare pulser width and alpha width to calibration spectra (shaping amp with 1us and gain 50x)
- Does photodiode data process OK or is it a problem with the oscillations?

Process LiF data
- Any pile up issues? Problems with gamma flash?

Online monitoring:
- Check leakage every few days, check lab temp.
- Check alpha peaks of 26Al contaminants - Gd, B.
 

Photos setup

Excel Sheet 

We switched from 10B target (number 1) to LiF target (number 3). We planned to take this measurement for one day.

Processed scans of both sides of the Li target showing the beam spot, and an image showing what it looks like to the eye.

 Steady for dE, E. Possibly rising on PHDI- monitor closely.

 E = 0.03uA
dE = 0.04uA
PHDI = 0.09uA

- Monitor PHDI - increasing slowly...

 E = 0.03uA
dE = 0.04uA
PHDI = 0.06uA

- Monitor PHDI - increasing slowly...

 At lunchtime (12.45)

E = 0.03 uA
dE  = 0.04 uA
PHDI = 0.06 uA

EFED 0.04uA
DEED 0.05uA
PHDI 0.13uA

 Morning - 9am

E= 0.03uA
dE= 0.04uA
PHDI= 0.06uA

Afternoon - 4.30pm

E=0.03uA
dE= 0.03uA
PHDI=0.05uA