HIE-ISOLDE diagnostic boxes Esteban D. Cantero CERN BE-BI-PM HIE-ISOLDE meeting for BE/BI 28 March...
14
HIE-ISOLDE diagnostic boxes Esteban D. Cantero CERN BE-BI-PM HIE-ISOLDE meeting for BE/BI 28 March 2014 The research leading to these results has received funding from the European Commission under the FP7-PEOPLE-2010-ITN project CATHI (Marie Curie Actions - ITN). Grant agreement PITN-GA-2010-264330.
HIE-ISOLDE diagnostic boxes Esteban D. Cantero CERN BE-BI-PM HIE-ISOLDE meeting for BE/BI 28 March 2014 The research leading to these results has received
HIE ISOLDE beam parameters Bunch period ~10 ns Freq RF ~ 100 MHz Projectiles: He to U 2 < A / q < < E/A < 10 MeV/u RIBs (pps to few pA). Stable beam (1 pA to 1 nA). Normal setup procedures use stable beams, and scale the accelerating and transport stages to the desired A/q. Repetition rate: 2 to 100 Hz. Macro pulse length: 50 to 500 s. Micro-bunches separated 9.87 ns. time 3
Citation preview
Experimental tests of HIE-ISOLDE beam instrumentation 28 March
2014
The research leading to these results has received funding from the
European Commission under the FP7-PEOPLE-2010-ITN project
CATHI (Marie Curie Actions - ITN). Grant agreement
PITN-GA-2010-264330.
OUTLINE
Instruments and devices.
Stable beam (1 pA to 1 nA).
Normal setup procedures use stable beams, and scale the
accelerating and transport stages to the desired A/q.
Repetition rate: 2 to 100 Hz.
Macro pulse length: 50 to 500 ms.
Micro-bunches separated 9.87 ns.
Short and Long diagnostic boxes
Due to tight space constraints in the longitudinal direction, we
had to implement two designs for the DBs:
Linac: Short DBs (6).
HEBT: Long DBs (12).
The functionality and operation of the instruments is similar in
the SDBs and LDBs. The only difference between them is that the
SDBs have a compact Faraday cup.
Depending on which devices are included on each DB, there can be up
to 4 different types/configurations of DBs.
scanning slit
stripping foils
2
preamplifier + VME-NIM modules
Collimators 2
Stripping foils
3 setpoints and continuous adjustment
* to avoid collisions, only one device at a time can be inserted on
each plane of the DB.
5
Beam intensity: Faraday cup (+ collimators).
Used every day for setting up the accelerator and aligning and
transporting the beam.
Beam transverse profiles (and position): Scanning slit + FC.
Horizontal and vertical profiles.
Beam longitudinal profile: Silicon detectors.
Energy and time spectra.
To obtain the time of flight, the spectra with the arrival time to
both detectors needs to be combined (measurements might take place
in parallel if we use an annular Si detector).
Energy spectra might be acquired during the cavities phasing
(daily/weekly). TOF spectra will be used to provide a calibration
point for E/A of the bending magnet (~twice a year).
Transverse emittance: 2 scanning slits + FC (or REX slit + grid
emittancemeter).
Once a year.
6
Faraday cup
A negative bias voltage is applied to a repeller cylinder in order
to avoid the escape of secondary electrons.
Current amplification and readout is implemented with a
preamplifier + VME board.
Repeller voltage and integration time can be modified by an expert
user.
Requires the time signal for the EBIS pulse in order to trigger the
charge collection loop.
plate
-Vrep
7
7
Scanning slit
A blade with a V-shaped slit is scanned upstream the FC.
Vertical and horizontal profiles are acquired, and the beam
position is calculated from them.
A 1 mm collimator hole is also included in the blade and can be
used for beam alignment.
The position of the blade needs to be controlled for the full
stroke (135 mm). The actuator is driven by a stepper motor.
Detector
Beam
8
8
Detector bias (60 or 100 V) supplied through the
preamplifier.
Preamplifier power: ±24 V, ±12 V provided by shaper
amplifier.
Leakage current monitoring can be used to determine detector aging
and also to block the beam if dose rate is too high.
Requires the time signal for the RF master-oscillator and the EBIS
pulse for triggering the TDC and gating the acquisition.
Integration time controlled by the user.
Works at an average rate of ~100s particles per second. Beam
intensity needs to be severely reduced placing collimating foils in
DB2 and DB3.
9
9
Si. detector + preamplifier + fast ADC (CAEN) + digital processing
of signal
(outputs peak height + timestamp)
(ADC outputs peak height, TDC outputs timestamp)
From peak height and timestamps, energy and timing spectra are
generated.
Gating with the EBIS pulse and leakage current monitoring is not
yet implemented.
10
10
Preset positions (1 to 4, or OUT) or arbitrary value.
Actuator driven by a stepper motor.
11
11
Beam transverse profiles:
Scan blade position while acquiring beamlet current with the
FC.
Transverse emittance:
Scan position of two blades while acquiring beamlet current with
the FC.
Si detector acquisition:
Time of flight measurements:
If the first Si detector is annular, beam can arrive to both
detectors at the same time.
The RF masterclock pulse is used as a time reference.
12
12
Limit switches, only IN – OUT position needed.
Collimators and stripping foils:
Scanning slit:
Stepper motor Ametek HY200 2226 0160.
Limit switches, accurate positioning (<100 mm) needed for all
the stroke (135 mm).
13
13
Thanks!