24 Feb 2006

Following changes to trigger was made:

1. The BigBite trigger is now just the Shower Sum. The Shower Sum goes
directly to the Total Shower Sum skipping the AND with the Preshower sum.
To compensate for this change 8ns cable was added after the Total shower
sum.

2. Remove the pulser from BigBite trigger and Neutron Arm Trigger.

25 Feb 2006

First time we have beam.
Electron trigger(T2) rates dependence to BB Total Sum(TS) threshold values was measured, based on run 2195.

Current: 5uA

Threshold (mV / MeV)	20 / 100	40 / 200	60 / 300
Rate (Hz)	1.014 *106	5.980 *104	1.830 *104

Current: 2uA

Threshold (mV / MeV)	60 / 300	80 / 400
Rate (Hz)	7430	2800

Current: 10uA

Threshold (mV / MeV)	80 / 400	100 / 500	120 / 600
Rate (Hz)	1.5 *104	6200	2700

26-27 Feb 2006

DC VME crates was changet to FastBus? crates.

28 Feb 2006

BB HV was adjasted using run 2429.
HV setting before adjastment:
/w/work3503/e02013/GEn/adaq.bk/adev/slowc/HV_BB/hv_set/bb_hv_28_02_2006_adj.set

Hv settings after adjastment:
/w/work3503/e02013/GEn/adaq.bk/adev/slowc/HV_BB/hv_set/bb_hv_28_02_2006_adj2429.set

Adjastment factors based on run 2429:
/w/work3503/e02013/GEn/adaq.bk/adev/slowc/scripts/adj_sh_2429.dat - for Shower.
/adj_ps_l_2429.dat - for left PS.
/adj_ps_r_2429.dat - for right PS.


Mean elastic scattering energy (860 MeV) was used for calibration.

01 Mar 2006

Background rate calculation for different beam positions.

Run #	Target	Current (uA)	Time (sec)	Ax	Ay	Bx	By	Rate (Hz)	Rate per uA (Hz/uA)
2461	Reff cell empty	1.194	290	-0.221	-1.451	-0.352	-0.751	0.328	0.275
2462	Reff cell empty	5.217	330	-0.318	-1.599	-0.387	-0.864	1.882	0.361
2463	Reff cell empty	0.625	325	-0.274	-1.333	-1.493	0.478	0.185	0.296
2464	Reff cell empty	0.629	295	-0.240	-1.433	-1.559	-2.826	0.234	0.372
2465	Reff cell empty	0.628	305	-0.263	-1.297	0.880	-0.920	0.262	0.417
2466	Reff cell empty	0.558	300	-0.281	-1.325	0.926	0.390	0.357	0.640

02 Mar 2006

Counting rates was calculated for Vacuum, HE3 and H2 targets, both for electrond and pions.
Based on runs 2461, 2473 and 2485.

Run #	Target	Current (uA)	Time (sec)	Ax	Ay	Bx	By	Electrons rate per uA (Hz/uA)	Pions rate per uA (Hz/uA)
2461	Vacuum	1.194	290	-0.221	-1.451	-0.352	-0.751	0.275	0.436
2473	He3	1.192	1837	-0.215	-1.639	-0.347	-0.817	4.551	3.194
2485	H2	2.145	1826	-0.268	-1.659	-0.354	-0.809	4.416	2.994

03 Mar 2006

BB Scintillators time resolution study.

For scintillators 5 and 6 was ploted following distribution:

(LT₅ + RT₅)/2 - (LT₆ + RT₆)/2, where
LT - left PMT time, RT - right PMT time, numerical index - scintilator bar number.
Sigma for this distribution was 1.48ns.


Then same distribution was ploted with cut on scintillators amplitude value:
LA₅>400 && RA₅>400 && LA₆>400 && RA₆>400, where
LA - left PMT amplitude, RA - right PMT amplitude, numerical index - scintilator bar number.
Sigma for this distribution was 0.45ns.

Same calculations was made form all scintillator bars, combined into pairs:
1&2, 2&3, 3$4 ... 11&12, 12&13.

Scintillator bars	Distribution	Cuts	Sigma	Comment
1 & 2	(LT1 + RT1)/2 - (LT2 + RT2)/2	LA1>400 && RA1>400 && LA2>400 && RA2>400	0.55	Small statistic
2 & 3	(LT2 + RT2)/2 - (LT3 + RT3)/2	LA2>400 && RA2>400 && LA3>400 && RA3>400	0.79	Small statistic
3 & 4	(LT3 + RT3)/2 - (LT4 + RT4)/2	LA3>400 && RA3>400 && LA4>400 && RA4>400	0.50
4 & 5	(LT4 + RT4)/2 - (LT5 + RT5)/2	LA4>400 && RA4>400 && LA5>400 && RA5>400	0.57
5 & 6	(LT5 + RT5)/2 - (LT6 + RT6)/2	LA5>400 && RA5>400 && LA6>400 && RA6>400	0.45
6 & 7	(LT6 + RT6)/2 - (LT7 + RT7)/2	LA6>400 && RA6>400 && LA7>400 && RA7>400	0.51
7 & 8	(LT7 + RT7)/2 - (LT8 + RT8)/2	LA7>400 && RA7>400 && LA8>400 && RA8>400	0.66
8 & 9	(LT8 + RT8)/2 - (LT9 + RT9)/2	LA8>400 && RA8>400 && LA9>400 && RA9>400	0.62
9 & 10	(LT9 + RT9)/2 - (LT10 + RT10)/2	LA9>400 && RA9>400 && LA10>400 && RA10>400	0.62
10 & 11	(LT10 + RT10)/2 - (LT11 + RT11)/2	LA10>400 && RA10>400 && LA11>400 && RA11>400	0.49
11 & 12	(LT11 + RT11)/2 - (LT12 + RT12)/2	LA11>400 && RA11>400 && LA12>400 && RA12>400	0.44
12 & 13	(LT12 + RT12)/2 - (LT13 + RT13)/2	LA12>400 && RA12>400 && LA13>400 && RA13>400	0.50

04-08 Mar 2006

Taking production runs on 1-st kinematics.

08 Mar 2006

Found out that signal from PS modules goes to ADC after 10X amplifier, Shower signal goes through summator, which amplification factor is 5x. Therefore in calibration program should be used PS amplitudes values divided by factor 2.

Starting second kinematics. Delays on trigger was changed.

1" acrylic shielding was installed on the front face of chamber 3 and a wall of plastic and aluminum was installed on the right side (facing detectors from target).

09 Mar 2006

Shower and Preshower HV has been changed to old - cosmic calibrated values.

HV setting file:
/w/work3503/e02013/GEn/adaq.bk/adev/slowc/HV_BB/hv_set/bb_hv_28_02_2006_adj.set

10 Mar 2006

Shower X and Y position finding algorithm in analyzer was changed.
Before it we used

X = x_ie_i / E,
where x_i and e_i is x-position and deposited energy of i-th block of the cluster.

Now X and Y position is X and Y position of central block of cluster.

11 Mar 2006

Starting PS calibration based on pion peak position.