1. Status of the PANDA Solenoid Magnet Production in BINP
PANDA meeting 2017 September E.Pyata

2. PANDA meeting 2017 September 4-9 E.Pyata
PANDA solenoid magnet
The PANDA solenoid is designed to provide a magnetic field of 2 T with a uniformity of ± 2% and radial magnetic field integral in the range 0 to 2 mm over the central tracking region. The magnet is characterized by a warm bore of 1.9 m diameter, a free length of 4 m and 22.4 MJ of stored energy.
Figure 1. Artistic cut side view of the solenoid magnet including contained detector systems.
PANDA meeting 2017 September E.Pyata

3. The main requirements to magnetic field of the PANDA solenoid magnet
Since PANDA is a fixed target experiment, the main technical challenge is the insertion of a warm target pipe vertically to the solenoid axis in correspondence with the interaction point located at 1/3 of the length of the solenoid. In order to meet the above requirement while satisfying the magnetic field homogeneity constraints, the magnet is split in 3 interconnected coil modules
Magnetic field
In the region occupied by the MVD and the central tracker there are very stringent requirements for the magnetic field homogeneity. According to these, the absolute magnitude of the field shall not vary by more than 2% from the nominal field of 2 T over the whole tracker region, which is the main aim of the magnet design.
Parameters of the magnetic field are summarized in Table 1.
Table 1. Parameters of the magnetic fields.
PANDA meeting 2017 September E.Pyata

4. The main milestones of production of the PANDA solenoid magnet
The scope of delivery includes:
Magnetic and engineering design of the magnet including tools and support;
Production and delivery of the magnet (consisting of yoke, cold mass and cryostat, alignment components, proximity cryogenics, support frame and platform beams) and all tools;
Power converter and quench protection and instrumentation.
Start contract
03/2017
Control assembling of the Yoke of solenoid at the BINP site
09/2019
Magnetic tests of the PANDA solenoid including safety system and electrical components at BINP (additional contract)
/2020
Assembling and tests at the FAIR site
Assembling of the Yoke at Darmstadt
03/2021
Acceptant tests at FAIR
08/2022
Installation of the PANDA solenoid magnet at worked position and start final acceptance tests
01/2023
Table 2. The main milestones.
PANDA meeting 2017 September E.Pyata

5. The main milestones of the yoke production
Memorandum BINP/ plant SibElectroTherm (SET)
05/2017
Presentation design of the yoke after technological work of drawings in FAIR
20-25/07/2017
PDR of the yoke
25-29/09/2017
FDR of the yoke
11/2017
Contract with SET
Purchasing raw materials
02/2018
Start of production
12/2017
Production of the first barrel octant
03/2018
Production of the all barrel octants
11/2018
Production of the frame and beams
Production of the doors
03/2019
Control assembling at SET
04/2019
Finalization of the parts
05/2019
Assembling of the Yoke at BINP
09/2019
Table 3. The main milestones of the yoke production.
PANDA meeting 2017 September E.Pyata

6. Figure 2. Process Flow Diagram of the PANDA cryogenic system.
PANDA solenoid 2017, TDR Flowscheme
The Process Flow Diagram (PFD) of the PANDA cryogenic system proposed by Udo Wagner (CERN) is shown in Fig 2. The main components of the cryogenic system are:
1. the cryostat, which includes:
• the superconducting coil cooled indirectly via the thermal contact with the aluminum support cylinder;
• thermal shields cooled by gaseous helium;
• the vacuum vessel;
2. the control dewar, which includes:
• a vessel for liquid helium;
• current leads;
• valves, gauges;
• vacuum shell.
3. a transfer line (Chimney) connecting the vacuum vessels of cryostat and control dewar;
4. transfer lines (TL) connecting refrigerator and control dewar.
Figure 2. Process Flow Diagram of the PANDA cryogenic system.
Flowscheme of the PANDA solenoid was approved.
PANDA meeting 2017 September E.Pyata

7. Figure 3. Modifying design of the cryostat and supports.
CDR of cryostat and Dewar box /2017
TDR cryostat vacuum vessel is designed as two concentric shells with thick annular end plates, all made of aluminum alloy The nominal wall thickness is 45 mm for the outer cryostat shell and 40 mm for the inner shell. The thickness of the flanges is 55 mm. The large thickness of the shells allows to minimize the displacement of the cold mass under the action of magnetic forces relative to its nominal position.
The deviation of the coil position from the nominal one within allowable limits may lead to magnetic decentering forces applied to the coil in axial direction and in a direction normal to the cryostat axis up to 168 kN and 51 kN respectively. So the total maximal force which can be applied to the cryostat in the horizontal plane (additionally taking into account the seismic acceleration of 0.75 m/s2) can be up to 185 kN.
The exact location of the cold mass inside the cryostat after its assembly should be defined with maximum precision. This is necessary to determine an optimal position of the superconducting coil inside the yoke aperture.
The target vertical pipe is traversing the magnet upstream of its centre at about 2/3 of the cryostat length. It will pass in between the two sub-coils of the solenoid through a warm bore in the cryostat. Therefore the cryostat for the superconducting coil is has to have two warm bores of 100 mm diameter, one above and one below the target position, to allow for insertion of internal targets.
The cold mass of the cryostat is suspended on four vertical rods. Eight horizontal tie rods of radial suspension fix the cold mass against shifts under the action of decentering magnetic forces and seismic loads in lateral direction. The axial tie rods (eight pcs.) hold the cold mass against its shifts due to decentering axial magnetic forces acting both in the cryogenic input direction and in the opposite one, as well as against seismic loads acting in axial direction. The position of the cold mass in axial direction is fixed in the area of the hole for the target (the fixation point is placed asymmetrically with respect to the cryostat center).
According to calculations of loads on the support of cold mass made by Helder Pais Da Silva (CERN) the loads are too high and we suggest using a different design of support (Fig. 3). Also material of the vacuum shell of the cryostat is stainless steel now. At this case mechanical and thermal loads should significantly decrease.
Figure 3. Modifying design of the cryostat and supports.
PANDA meeting 2017 September E.Pyata

8. Figure 4. Longitudinal section of the cryostat with cold mass.
PANDA solenoid 2017, cold mass
The PANDA solenoid is designed to provide a magnetic field of 2 T over a length of about 4 m in a bore of 1.9 m.
The solenoid is split in 3 inter-connected coils. A view of the Target Spectrometer, including the magnet is shown in Figure 1. Each coil is a six layers solenoid enclosed in a coil casing to rigidly contain the internal forces exerted on the conductors due to the magnetic field. The coils and the coil casing constitute the cold mass, which must be maintained at liquid helium temperature (~ 4.2 K) in order for the winding to be in the superconducting state. The cooling of the cold mass is achieved indirectly through the circulation of liquid helium in pipes welded on the coil casing. The TS solenoid is designed to operate at a current of ~5 kA. The conductor is a superconducting NbTi/Cu wire based Rutherford cable co-extruded in a high purity aluminum stabilizing matrix, featuring high electrical and thermal conductivity. The production design and contractual follow-up of the construction of the cold mass including the conductor manufacturing, its integration into the cryostat and test have been committed by the PANDA Collaboration to BINP.
Thickness (after cold work) at 300 K mm
7.93
± 0.03
Width (after cold work) at 300 K
10.95
Critical current (at 4.2 K, 5 T) A
> 14690
Critical current (at 4.5 K, 3 T)
> 16750
Overall Al/Cu/sc ratio
10.5/1.0/1.0
Aluminum RRR (at 4.2 K, 0 T)
> 1000
Al 0.2% yield strength at 300 K
MPa
> 30
Table 4. Conductor mechanical and electrical parameters.
Figure 4. Longitudinal section of the cryostat with cold mass.
Figure 5. Cold mass cross-section.
PANDA meeting 2017 September 4-9 E.Pyata
Figure 6. Drawing of the conductor.

9. PANDA meeting 2017 July 20-25 E.Pyata Conductor
PANDA solenoid 2017, Conductor Cost ???
Conductor`s manufacturers
Furukawa, Japan - according to CERN specification, 1.5 year production time
But now absent possibility to produce extrusion of Rutherford cable to Al.
2. BINP, 1.1 year production time, if samples will produce according to CERN specification
A.A. BOCHVAR HIGH-TECHNOLOGY SCIENTIFIC RESEARCH INSTITUTE FOR INORGANIC MATERIALS (VNIINM), Russia – strands - according to CERN specification
VNIINM and k - Rutherford cable, according to CERN specification
BINP, extrusion of Rutherford cable to Al, according to CERN specification
Hitachi, Japan - according to CERN specification, ? year production time – closed production from 2013 (last project – Mu2e)
Supercon, USA - according to CERN specification, ? year production time
Production of the Rutherford cable: Furukawa, VNIINM, Supercon, Bruker…
PANDA meeting 2017 July E.Pyata Conductor

10. PANDA meeting 2017 September 4-9 E.Pyata
PANDA solenoid 2017, Power Supply and Energy Extraction System for the PANDA magnet
Responsible person - Dr. Erokhin Alexandr, BINP
Requirements for the external protection system (Quench detection and Energy Extraction):
The amount of the stored energy to be extracted is 22.4MJ. Stored energy should be extracted to the external dump resistor with the value of 0.1 Ohm. The active elements of the dump resistor should not be hotter than 100C.
Power Supply (four VCH1300) – parameters
Nominal output power 61,2kWt;
Nominal output current 5100А;
Nominal output voltage 12V;
8 hours run Stability - < 0.01% from nominal;
Output ripples in voltage:
0-300Hz - < 10mV rms,
0-40кГц – < 100mV rms;
Control Interface – CAN
Form factor 19” x 3U
Conceptual Design Report was presented in FAIR GSI,
FDR /2018
PANDA meeting 2017 September 4-9 E.Pyata

11. Thank you for your attention
PANDA meeting 2017 September 4-9 E.Pyata