FXT Target Evaluation

Executive Summary:
Were were able to run FXT during CeC run with 26.53 GeV/n Au beam (sqrt(sNN) = 7.1 GeV).  We look at EPD/BBC ew coincidences and the inclusion of TOF > 0.  We did see FXT collisions, what we will need to do next time is:
1) Adjust the timing for the FXT.
2) Scan in TOF threshold
3) Scan in EPD # hits

We will also reproduce the data without the beamline and expanding Vr out to 6 cm.  This can be done prior to the next CeC run.  (Done - See drupal.star.bnl.gov/STAR/system/files/RReedFXT04242018.pdf - This definitely brings back the peripheral collisions!)

Analysis

A first look at the data:
drupal.star.bnl.gov/STAR/system/files/RReedFXTv1_04212018.pdf


Figure 1. FXT ADC from the East on the left.  FXT ADC from the West on the Right.  Blue represents hits with good TAC (300 < TAC < 4095), Red represents hits with bad ADC.  We see on the right that the timing was not set quite right for the west.


Figure 2. TAC from the FXT on the East on the left and TAC from the FXT on the West on the right.  We see here that the timing needed to be adjusted as the TAC distribution is not centered.

Some results from the 1.5M produced by hand:


Figure 3. (Left) Refmult for fixedTarget_bbc (BBC-E +!BBC-W+TOF0, black), fixedTarget_bbc with Vy < -1 cm (red), fixedTarget_bbc_notof (BBC-E +!BBC-W, blue) and fixedTarget_bbc_notof with Vy < -1 cm (green).  The same distributions using the number of tracks used to construct the vertex is on the right.  These are only for the index 0 vertex.

Figure 4. (Left) Refmult for fixedTarget_epd (EPD-E +!EPD-W+TOF0, black), fixedTarget_epd with Vy < -1 cm (red), fixedTarget_epd_notof (EPD-E +!EPD-W, blue) and fixedTarget_epd_notof with Vy < -1 cm (green).  The same distributions using the number of tracks used to construct the vertex is on the right.  These are only for the index 0 vertex.


Figure 5. (Left) Vertex distribution for all vertices (black) and for those with Vy < -1 (red).  (Right) Vx vs Vy for all vertices.

Akio's proposal: (gate for BBC/EPD moved earlier by 15nsec)

BBC_QT_E_Sm_Gate_End_Delay 16   -> 1
BBC_QT_E_Sm_Gate_Start_Delay 1    -> 93
BBC_QT_E_Sm_TAC_Max  2400 -> 1500
BBC_QT_W_Sm_Gate_End_Delay 16   -> 1
BBC_QT_W_Sm_Gate_Start_Delay 1    -> 93
BBC_QT_W_Sm_TAC_Max         2400 -> 4000

TCD config/RCC/BBC              -1 (176=0xB0) -> 146=0x92

EPD_QTc_Gate_End_Delay  39  -> 24
EPD_QTc_Gate_Start_Delay 23  ->  8
EPD_QTc_TAC_Stop  64  -> 34

and we should take 3 quick short runs (~50k events)

enabled "bbce" only (unprescaled to reasonable rate)
enabled "epde" only (unprescaled to reasonable rate)
all trigger enabled


Notes from Bill regarding FXT running:

During this dedicated CeC running RHIC is operated
with Au beam, only in the Yellow ring, at a beam energy of 26.53 GeV/n.
In the current store it is with just 6 bunches.

  Akio set the BBC HV values to those used for pp running, to make it
sensitive to single mips.

I'd told C-AD to expect to find the upped edge
of the target at about -1.8 cm, +- 2 mm. In this year's installation
we'd set the target foil Z location at 200 cm to the West of the center
of STAR (i.e. at West edge of TPC), and our goal was to set the height
at about the same level as earlier running.
     We first saw that it looked like the target was getting hit with
the beam elevation at -~ 1.6 cm. We then had Angelika drop the beam
elevation by ~30 um, and saw the trigger rate increase by something like
15%. This tells us that there is a profile to the beam, and we should be
able to dial in a desired trigger rate, assuming that the RHIC beam
orbit is stable through STAR.

Notes on trigger and from run log below

TRIGGER LABEL    STREAM    DAQ TRIGGER ID(s) OFFLINE TRIGGER ID(s) PRESCALE EVENTS
fixedTarget_bbc        physics        1    1    1.0    343370
+TOFmult0
+EPD-E
-EPD-W
-Laser-protection
fixedTarget_bbc_no_tof     physics     2     2     284.9     16805
+BBC-E
-BBC-W
-Laser-protection
fixedTarget_epd     physics     8     4     1.0     311277
+TOFmult0
+EPD-E
-EPD-W
-Laser-protection
fixedTarget_epd_no_tof     physics     10     5     262.0     17804
+EPD-E
-EPD-W
-Laser-protection

Run Log notes:

Run 19109035 - fixedTarget_2018 TRG+DAQ+TPC+iTPC+BTOW+TOF+eTOF+MTD+GMT+L4
Run 19109035 - Run stopped per Jeff’s request. Start next run: fixedTarget_2018 TRG+DAQ+TPC+iTPC+BTOW+TOF+eTOF+MTD+GMT+L4.
Run 19109036 - Run stopped after ~30 minutes. Start next run.
Run 19109037 - fixedTarget_2018 TRG+DAQ+TPC+iTPC+BTOW+TOF+eTOF+MTD+GMT+L4 stopped after ~35 minutes. Start next run.
Run 19109038 - fixedTarget_2018 TRG+DAQ+TPC+iTPC+BTOW+TOF+eTOF+MTD+GMT+L4 stopped as the laser was ready.
Run 19109039 - TPC laser switched off after 3.8k laser triggers had been recorded.
Run 19109039 - Run stopped after ~20 minutes after Angelika made a (further) adjustment to the beam position. The "physics" trigger rates are now ~350Hz, about an order of magnitude higher than for the previous runs.
Run 19109040 - fixedTarget_2018 TRG+DAQ+TPC+iTPC+BTOW+TOF+eTOF+MTD+GMT+L4 stopped after ~30 minutes. Start next run.
BBC-E ~6.3 kHz, BBC-W ~3.6kHz, VPD-E ~1.7kHz, VPD-W ~0.1kHz, fixedTarget_bbc trigger ~290Hz, fixedTarget_epd trigger ~265Hz.
Run 19109041 - fixedTarget_2018 TRG+DAQ+TPC+iTPC+BTOW+TOF+eTOF+MTD+GMT+L4 stopped after ~30 minutes. Start next run.
16:15 General Ion beam intensity has dropped to ~0.9x10^9 per bunch.
Run 19109042 - fixedTarget_2018 TRG+DAQ+TPC+iTPC+BTOW+TOF+eTOF+MTD+GMT+L4 stopped after ~30 minutes. Start next run.

Took over a working experiment from the overnight shift and continued data collection with Zr fill 21608. About 19M events were collected. Subsequently, fixed-target running was brought online concurrent with (and parasitically to) CeC development, c.f. Bill's summary to starops. Runs x040, x041, and x042 were taken with 200-300 Hz "physics" rates. When isobar running is resumed, the BBC gains need to be restored and Akio wants to be called.

run number | status | nEvents | glbSetupName             | runFlags       
----------------------------------------------------------------------------
19109030   |      ? |   40544 | fixedTarget_2018         | Just at Test Run
19109031   |      ? |   97099 | fixedTarget_2018         | Just at Test Run
19109032   |      ? |  418747 | fixedTarget_2018         | Just at Test Run
19109033   |      ? |  231003 | fixedTarget_2018         | Just at Test Run
19109034   |      ? | 2493213 | fixedTarget_2018         | Just at Test Run
19109035   |      ? | 1312816 | fixedTarget_2018         | Just at Test Run
19109036   |   good |  277816 | fixedTarget_2018         |                
19109037   |   good |  279877 | fixedTarget_2018         |                
19109038   |   good |  277765 | fixedTarget_2018         |                
19109039   |   good |  187548 | fixedTarget_2018         |                
19109040   |   good |  733203 | fixedTarget_2018         |                
19109041   |   good |  536048 | fixedTarget_2018         |                
19109042   |   good |  628232 | fixedTarget_2018         |                

Run 19109043 - fixedTarget_2018 TRG+DAQ+TPC+iTPC+BTOW+TOF+eTOF+MTD+GMT+L4
Run 19109044 - fixedTarget_2018 TRG+DAQ+TPC+iTPC+BTOW+TOF+eTOF+MTD+GMT+L4
Run 19109044 - At JH's direction:
Added 2 triggers to fixedTarget_2018:
1. a bare tof trigger
2. a tof0 along with the logical or of BBCE, EPDE, VPDE, ZDCE with a veto of !BBCW and !EPDW and !VPDW and !ZDCW. This is meant to be as clean a trigger as possible for the fixed target (though heavily biased).
Also added a new configuration file fixedTarget_clean_2018, with modified BBC/EPD gates, for use by Akio
Run 19109045 - fixedTarget_2018 TRG+DAQ+TPC+iTPC+BTOW+TOF+eTOF+MTD+GMT+L4

Monitors below
bbce             physics     80     8     293.4     16893
bbcw             physics     100     9     132.9     20125
bbcew             physics     200     10     8.5     19865
epde             physics     400     11     271.8     17995
epdw             physics     800     12     22.0     21796
epdew             physics     1000     13     9.8     23087