The rootfiles countsB.root and countsLi.root contain histograms of count spectra that would be expected at n_TOF for a 10B and a 6Li target, respectively. The units in y are arbitrary. This can be used to check, if we can reproduce the expected trend with our Li and B measurements. So the histograms called "counts" can be directly compared to the histograms called "energy" in Sili_deed.c (they should have the same binning). You need to scale the histogram to get a decent overlap. You can use this also to estimate the neutron energy calibration - the thermal bump at low energy will give you a good idea of the flight path length. Structure at high energy will give you a better idea on the offset.

The files 6Li_endf.root and 10B_endf.root are the original cross section files, and countrate_calc.C is the file used to produce the count spectra.

Setup 5.10.22

dE 20 um (ID 2837-33) and 494 um double sided (ID 1194-9)

46 channels (2 connectors missing)

LiF4 in beam 

dE: Big flat cables from preamp 22 and 23 into 1A and 1B

E: from preamp 24+25 go into 2A, 2B and 3A 3B

LEMO converter box: Cable 1: dE

                                   Cable 3: E n+n

                                  unlabeled cable: E p+n

E detector voltage: -133 V, leakage current -0.53 micro-Amp

dE detector voltage -22 V, leakage current -0.03 micro-Amp

For the E detector one of the edge p+n strip bond-wires is suspected broken.

DEED 6 and 9 no signal throughout the campaign.

EFED 27 high oscillations in baseline throughout the campaign.

Spreadhseet made for shifters to manually enter that they have checked each signal and that they can see gamma-flashes. It is saved as "26Al_EAR2_Signal_Checks.ods", it is located on the second monitor on the right of the control room, next to the monitor used to see the beam intensity (same monitor used to see signals).

It will stay open throughout the campeign. Shifters have been told to check signals more than just the once to record that they're okay, and there is a comments box for shifters to add any comments/issues that arises after they have recorde that they have checked the signals at least once.

14 bit card replaced for DEED 9-12, to prevent issue with pulser arriving before gamma flash.

This morning 2x RAL108 +/-15V PSUs were borrowed from the Edinburgh equipment in the ISOLDE hall to check whether the same transient noise is observed at the +/-15V PSU 
outputs - this was confirmed. See https://elog.ph.ed.ac.uk/nToF/63

Following this test the same 2x RAL108 +/-15V PSUs were tested in the ISOLDE hall ( 19" rack adjacent to the HIE-ISOLDE GP scattering chamber ). 


PSU #1 Coutant HSC15-3.0

Setup and PSU details - attachments 1-4

DSO ch#1 +15V AC/1M, ch#2 -15V AC/1M - y: 5mV/div x: 400ns, 4us & 40us/div - attachments 5-7


PSU #2 Farnell MX2

Setup and PSU details - attachments 8-10

DSO ch#1 +15V AC/1M, ch#2 -15V AC/1M - y: 5mV/div x: 400ns, 4us & 40us/div - attachments 11-13


Conclusion 

The noise of the 2x RAL108 +/-15V PSUs differed somewhat ( frequency and structure of HF transients ) from each other in the ISOLDE test.

Compared to the EAR2, n_TOF test the amplitudes were c. 10x smaller and the HF transient frequency and structure differed.

This appears to confirm that the primary problem is the ac mains power in EAR2, n_TOF - input and/or output filtering is required.

On the morning of Monday 14 August 2x RAL108 +/-15V PSUs were borrowed from the Edinburgh equipment in the ISOLDE hall to check whether the same transient 
noise is observed at the +/-15V PSU outputs.


PSU #2 Farnell MX2

Setup - attachment 1

DSO ch#1 +15V AC/1M, ch#2 -15V AC/1M - y: 50mV/div x: 1us, 500ns, 250ns & 25us/div - attachments 2-5



PSU #1 Coutant HSC15-3.0

Setup - attachment 6

DSO ch#1 +15V AC/1M, ch#2 -15V AC/1M - y: 50mV/div x: 25us/div - attachment 7


Conclusion

Observe same amplitude and HF structure with all 3x RAL108 +/-15V PSUs

PSU Calex

Setup, PSU and ac mains filter - attachments 1-3


DSO ch#1 +15V AC/1M, ch#2 -15V AC/1M - y: 50mV/div x: 100ns, 200ns, 1us, 2us, 10us/div

Without ac mains filter - attachments 4-8



DSO ch#1 +15V AC/1M, ch#2 -15V AC/1M - y: 10mV/div x: 100ns, 200ns, 1us, 2us, 10us/div

With ac mains filter - attachments 9-13

Conclusion - Claud Lyons Ltd STF Series Surge & Transient Power Filter produces c. x 2 attenuation of HF noise transients

PSU Calex

Setup and PSU details - attachments 1-3

DSO ch#1 +15V AC/1M, ch#2 -15V AC/1M - y: 20mV/div x: 100ns, 200ns, 1us, 2us, 10us, 20us & 100us/div - attachments 4-10

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